4866 4870.output

* GB785273 (A)

Description: GB785273 (A) ? 1957-10-23

Improvements in and relating to a holder for a thermionic valve, electricalplug or other device having projecting terminal prongs

Description of GB785273 (A)

PATENT SPECIFICATION 785273 m Date of Application and filing Complete Specification: March 16, 1956. No 8367156. Application made in United States of America on May 27, 1955. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 38 ( 1), E 3 (A 4 C: Al IB: C 2 A: C 2 C: D 3: E 4 B), E 1 OX. International Clasification:-HO 2 f. COMPLETE SPECIFICATION Improvements in and relating to a Holder for a Thermionic Valve, Electrical Plug or other Device having Projecting Terminal Prongs We, CINCH MANUFACTURING CORPORATION, a Corporation organised according to the laws of the State of Ilinois, United States of America, of 1,026, South Homan Avenue, S Chicago 24, Illinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to holders for thermionic valves, electrical plugs or other devices having projecting terminal prongs and is particularly adapted for holders for use with supporting panels having electrical circuits, printed, etched or otherwise formed thereon. According to the present invention a holder for a thermionic valve electrical plug or other device having projecting terminal prongs comprises a body of insulating material having prong-engaging contacts mounted thereon, each of said contacts having a terminal portion extending beyond one face of the body and formed with an attaching portion at its outer end, said attaching portion including a resilient reverse-bend end portion adapted to be inserted into an aperture in a

supporting panel so as to resiliently engage the portion of the panel adjacent to said aperture. The invention also includes an electrical assembly comprising a panel having a series of apertures, electrical circuits carried by said panel and having ends terminating adjacent said apertures, a holder for a thermionic valve or electrical plug assembled on said panel and including a body of insulating material, carrying prong-engaging contacts, each of said contacts having a terminal portion extending beyond said body and formed with an attaching portion at its outer end, including a reverse-bend portion disposed in one of said apertures and resiliently engaged with an end portion of said electrical circuits. To enable the invention to be fully underF Pr stood it will now be described with reference to the accompanying drawings, in which: Fig 1 is a side elevation of a valve holder according to one embodiment of the inven 50 tion; Fig 2 is a plan view of the holder shown in Fig 1; Fig 3 is an under plan view of the holder shown in Figs 1 and 2; 55 Fig 4 is a side elevation of an assembly including a supporting panel carrying printed circuits and a holder having contact terminals positioned with relation to the printed circuits for permanent electrical connection 60 with the circuits; Fig 5 is a plan view of a fragment of the supporting panel showing the openings in the panel through which the attaching elements of the contact members of the holder are 65 adapted to extend, Fig 6 is an under plan view of the assembly illustrated in Fig 4; Fig 7 is an enlarged view showing the attaching portion of a contact member in 70 soldered electrical connection with a printed circuit, Fig 8 is an enlarged section taken along the line 8-8 of Fig 6; Fig 9 is an enlarged section taken along 75 the line 9-9 of Fig 6; Fig 10 is a front elevation of the contact member carried by the holder; Fig 11 is a side elevation of the contact member shown in Fig 10, and go Fig 12 is a partial section taken along the line 12-12 of Fig 9 illustrating the bowed shape of the terminal portion of the contact member. Referring to the accompanying drawings, 85 Figs 4 and 6 illustrate an assembly which includes a supporting panel 1 of insulating material having an upper surface 2 and a lower surface 3 The panel 1 has a circular series of openings 4 each of which is prefer 90 ably of rectangular shape and an opening 5 disposed in the centre of the series of openings 4 The panel 1 may carry printed circuitry on both upper and lower surfaces, but as shown printed circuits 6 are disposed on the lower surface 3 only Each of the printed circuits 6 has an end portion 7 which terminates adjacent an opening 4 An earth printed circuit element 8 is also provided which has an end portion 9 terminating adjacent the opening 5 A holder 10 for a thermionic valve

or plug (not shown) carrying contact members 11 is secured in presoldering assembly with the panel 1 Each of the contact members 11 has a terminal element carrying an attaching element at its free IS end which extends through an opening 4 of the panel I and in final assembly of the parts is soldered into electrical connection with a printed circuit 6. Referring in detail to the construction of the holder 10, it includes a lower insulating plate 12 and an upper insulating plate 13. The lower plate 12 has a plurality of contactreceiving openings 16 which are arranged substantially in a circle Notches 17 (Fig 3) are preferably formed in the outer marginal edge of the plate 12 spaced radially of the openings 16 for receiving terminal elements 11 of the contact members The upper plate 12 has a circular series of openings 18 conforming to the spacing and arrangement of the openings 16 of the plate 12 The plates 11 and 12 carrying the contact members 11 are secured in assembly by a centre shield or rivet-like member 19 which extends through aligned openings (not shown) in the centres of the superposed plates in the manner well known in the art. Referring to Figs 10 and 11 which illustrate one form of the contact member 11, the contact is formed from a single piece of spring metal and provides a substantially flat base element 20 having an opening 21 Wing elements 22 in opposed relation one to another extend downwardly from opposed sides of the base element and form a generally rectangular body (viewing the broad surface of a wing 22) adapted to be snugly received within the openings 16 of the plate 12 The wing elements 22 are formed of stiff yet flexible material and have, converging portions 23 at their outermost ends The space between the outermost edges 24 of each pair of converging portions 23 is normally less than the diameter of the prong terminals (not shown) of a valve or plug to be engaged by f tie outer edges and flexing of the portions 21 is limited by the wvalls of the openings 16 of the plate 12 Each of the contact members 11 has a relatively stiff terminal portion 25 integrally joined to the base element 20 adjacent an end 20 a thereof, and normally extending away from the base 20 at an angle slightly greater than a right angle. Each of the terminal portions 25 is of generally bowed cross-sectional shape, as illustrated in Fig 12, thereby increasing the stiffness and rigidity of this part of the contact member It will be noticed that the base 20 is of bowed cross-sectional shape adjacent its junction 20 a with the terminal portion 25 70 (Fig 11) so that flexing of the terminal portion 25 relative to the base 20 is restricted. An attaching portion 25 a is joined to the outer end of each terminal portion 25 and includes a leg portion 26 which is integrally 75 joined to the central end portion of the terminal portion 25 The leg portion

26 is of reduced width compared with the terminal portion 25 with the result that shoulders 27 are formed at the outermost end of the ter 80 minal portion 25 adjacent its junction with the leg portion 26 A spring portion 28 is integrally joined to the outermost end of the leg portion 26 The spring portion 28 is in the form of a reverse-bend portion and pro 85 vides a curved lead portion 29 on its lowermost side and a shoulder element 30 adjacent its outermost end substantially facing the plates 12 and 13 of the holder. In assembly of the contact members 11 90 with the insulating plates 12 and 13, the base elements 20 of the contact members are disposed between the plates and supported by the plate 12 Opposed wing elements 22 of each contact member are seated within an 95 opening 16 of the plate 12 and the terminal elements 25 are disposed within the notches 17 of the plate 12 As a result of the fact that each of the terminal elements 25 is joined to its respective base element 20 at an angle 100 greater than a right angle, the terminals 25, in final assembly of the parts of the socket, will diverge slightly from the vertical axis of the holder as represented by the centre shield 19 l O In assembling the holder 10 to the supporting panel 1, the lower ends of the attaching portions 25 a are moved into their respective apertures 4 to engage the lead portions 29 with the outer walls 31 of the apertures 110 4 As a result of the fact that the greatest distance between the leg 26 and the reversebend portion 28 is greater than the distance between opposed walls 31 and 32 of the opening 4, the spring portions 28 will be 115 contracted during passage through the apertures 4 after which they will expand to engage portions of the shoulders 30 behind the lower surface 3 c' the panel 1 as most clearly shown in Fig 8 it will be noted that during 120 the action in which the attaching portions a are forced throughl the apertures 4 the terminal portions 25 will move inwardly slig htly by flexure at the Points of junction a to move the leg portions 26 into engage 125 meat with the wjalls 32 of the apertures 4. When Lhe reverse-bend portions 28 are in final 2 ssembly xvith the nanel 1, the shoulders 27 abut the nupper surface 2 of the panel 1 and serve to relieve the strains on the soldered 130 785,273 terminating adjacent said apertures, a holder for a thermionic valve or electrical plug au 60 sembled on said panel and including a body of insulating material carrying prong-engaging contacts, each of said contacts having a terminal portion extending beyond said body and formed with an attaching portion at its 65 outer end, including a reverse-bend portion disposed in one of said apertures and resiliently engaged with an end portion of said electrical circuits. An electrical assembly according to 70

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* GB785274 (A)

Description: GB785274 (A) ? 1957-10-23

Artillery cartridge-cases and their manufacture


A high quality text as facsimile in your desired language may be available amongst the following family members:

BE546873 (A) DE1037322 (B) FR1125581 (A) BE546873 (A) DE1037322 (B) FR1125581 (A) less Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPECIFICATION 785,274 Date of application and filing Complete Specification: March 21, 1956. No 8840/56. Application made in France on May 3, 1955. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Classes 9 ( 1), A 1 A; 83 ( 2), A 25; and 83 ( 4), U 3, Z. International Classification:-B 21 d B 23 j, p F 07 f.

COMPLETE SPECIFICATION Artillery Cartridge-Castes and their Manufacture We, FORGES ET ATELIERS DE CONSTRUCTIONS ELECTRIQUES DE JEUMONT, of 5 Place de Rio de Janeiro, Paris ( 8), France, a French Body Corporate, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:The invention relates to artillery cartridgecases comprising a tubular portion in the form of a rolled-up sheet, and a metallic base to which an inturned end of said tubular portion is secured, as by setting or clamping in order to provide a sliding joint. It has already been proposed to secure the parts together, either by a screw and nut connection, or by crushing down a wall or parallel lips, provided upon the base and arranged to secure the inturned end of the tubular portion, or again by interposed washers. When the cartridge-cases are of great length and especially of small diameter, the application of these known methods of assembly presents numerous practical disadvantages, such as high cost price, excessive weight and volume of the fixing, difficulties of manufacture, impossibility of utilising the most appropriate qualities of steel for the base, and so on More particularly, the positioning of the inturned extremity of the tubular portion between the lips of the base imposes excessive strains on the metal of the tubular portion. The present invention has for its main object to avoid these disadvantages and difflculties by improved structure and a novel method of manufacture, characterised in that the base comprises a deformable crown which is surrounded by a rigid washer adapted to compress the inturned end of the tubular portion against the base, said washer being provided with a central frusto-conical hole into which the deformable crown is expanded to take a bell-mouthed shape for selPrice 3 s 6 d l curing the parts together so as to obtain a sliding joint. The invention is hereinafter described with reference to the accompanying draw 50 ing, which represents diagrammatically and by way of example one embodiment thereof; in this drawingFig 1 is a vertical section of a cartridgecase before the securing of the tubular por 55 tion, and Fig 2 a partial vertical section of a finished cartridge-case. In Fig 1, there is seen a tubular portion 1 of the cartridge-case which may be cylindrical, or frusto-conical as represented, as 60 well as its base 2, which is made of steel of good quality, these two parts having to be assembled by a setting or clamping operation A rigid washer 3 having a frusto-conical hole in the middle is lodged in the in 65 terior of the part 1; if this latter is conical, as shown, the

washer 3 must be inserted into the part 1 before turning in the lower end 4 as represented. The base 2 comprises a deformable crown 70 A having a vertical axis, the lower part of this crown being surrounded by the inner bevelled edge of the washer 3 In order to effect the setting, there is first applied to the washer 3 a suitable vertical pressure by 75 means of a hollow punch 6, in order to hold the inturned edge 4 upon the base 2, after which an axial punch 7 having a frusto-conical lower end is made to descend, which expands the crown 5 A and gives it the bell 80 mouthed shape represented at 5 B in Fig 2. This deformation ensures the correct assembly of the parts 1 and 2, while yet retaining the appropriate compression of the inturned edge 4, necessary for the obtain 85 ing of the desired sliding joint. It will be seen that the invention eliminates the disadvantages and difficulties pointed out above, by simple and inexpensive means In comparison with the analo 90 gous arrangements already known utilising locking washers, the new arrangement is distinguished particularly by the fact that the compression of the sliding joint and the final deformation of the base crown only, intended to secure the assembled parts together, are effected successively by distinct operations, which allow of accomplishing these stages of manufacture in the respective optimum conditions. It is to be understood that the shapes of the parts 1, 2 and 3 may be modified in divers ways. If the tubular portion 1 of the cartridgecase is of frusto-conical shape, as represented, the washer 3 will conveniently be inserted therein before the lower end is inturned Moreover, the number of successive operations may be different from two. it is possible, for example, first to lower the punch 7 in order to deform the crown 5 A and give it the shape 5 B, thereafter to apply an appropriate internal hydraulic pressure in order to shape the tubular portion 1 and to compress its inturned edge 4, and to utilise the punch 7 a second time in order to complete and finish the final deformation of the crown SB.


* GB785275 (A)

Description: GB785275 (A) ? 1957-10-23

Electric ceiling switch


A high quality text as facsimile in your desired language may be available amongst the following family members:

BE557043 (A) DE1017680 (B) FR1147883 (A) NL95474 (C) BE547378 (A) FR71185 (E) NL93680 (C) BE557043 (A) DE1017680 (B) FR1147883 (A) NL95474 (C) BE547378 (A) FR71185 (E) NL93680 (C) less Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPECIFICATION f i ' Date of Application and filing Complete Specifica NO 12549156. Application made In Germany on April 27, 1955. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 38 ( 5), B 1 N( 3: 6: 11), B 2 (A 18: C 6 C 2). International Classification:-HO 2 c. COMPLETE SPECIFICATION Electric Ceiling Switch We, BUSCH JAEGER DURENER METAL WERKE AKTIENGESELLSCHAFT, a Body Corporate organised and existing under the laws of Germany, of Ludenscheid, Westphalia, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - Electric switches with pressure contacts exist, in which contact springs are controlled by radial or axial cams If such switches, which

are better suited for alternating current, are designed as ceiling switches, there are required in addition to the control cams special intermediate members which complicate an otherwise simple switch and increase the cost thereof. According to the invention, therefore, the driving means of known rotary ceiling switches are combined with those of cam switches In this arrangement, a form of control cylinder, rotated step-by-step by a pull-cord through a pawl, and periodically axially displaced by a detent, controls by means of its axial movements a contact spring which cooperates with fixed contacts provided in the switch The contact spring in turn engages in the manner of a claw around a projection or flange extending around the control cylinder, such projection or flange carrying the contact spring with it in its axial movements. A further feature of the invention resides in a stirrup mounted on a base of insulating material, the said stirrup being U-shaped in itself, while the U-arms thereof, which serve to support the switch pin, are in turn of stepped form The ends of the said U-arms extend through slots in the base, and are twisted to secure them therein The web of the U-shaped stirrup is formed with a hole through which a pull cord passes and in which the pull-cord is guided. The invention further provides an improved method of securing a cover member lPrice 3 s 6 d l ji 5275 tion: April 24, 1956. on the switch For this purpose, projections are pressed out of the material of the upper ends of the U-arms of the stirrup to engage in the turns of the internal screwthread of 50 the mounted cover and thus hold the latter fast upon the base. The invention may be carried into practice as diagrammatically illustrated in the seven figures of the accompanying drawing, 55 in which Figures 1 and 2 each show a side elevation of a switch according to the invention with its cover removed and illustrate the alternative positions of the control cylinder with the contact lever, 60 Figure 3 is a plan view of the switch with its cover removed, Figure 4 is a side elevation, also with the cover removed, Figure 5 is a view, partly in section, of the 65 switch with its cover in position, Figure 6 is a sectional view of the switch with the cover removed and, Figure 7 shows the forward end of the Uarms on a larger scale 70 A control cylinder 1 (Figure 1) mounted on a spindle 2 and driven by a pawl 3 is held fast by the engagement of recesses in the cylinder 1 with detents 4 formed in one arm of a U-shaped member 5 When the cord is 75 pulled, the control cylinder is disengaged from the detents 4 against the pressure of an axial spring 6 and brought into the next position of engagement, in which the recess is only of small depth While the detent pro 80 jections in the U-shaped member 5 are of equal height

the recesses in the control cylinder are alternately deeper and shallower. The control cylinder is thus axially displaced from one position into the other to the ex 85 tent of the difference of the depths of the recesses in the cylinder. The control cylinder 1 is provided with a surrounding projection or flange 7, around which a contact spring 8 engages from both 90 sides in the manner of a claw The contact spring 8 is rocked by the axial movements of the control cylinder The positions of the spring 8 are apparent from Figures 1 and 2 and 3 As shown in Figure 5, the arms 9 of the U-shaped member 5 are stepped and are passed through apertures 10 in a base 11. The ends 12 of these arms are twisted so as to secure them in position on the base. Projections 13 are pressed out of the material of the lower U-arms below the base 11 (Figures 5 and 7) and engage in the internal screw-thread of a cover member 14. When the cover is tightened, the turns of the screwthread bear against the projections 13 and the lower edge of the cover 14 bears on the edge of the lower face of the base 11.


* GB785276 (A)

Description: GB785276 (A) ? 1957-10-23

A hearth stand


PATENT SPECIFICATION T 75,276 Date of Application and filing Complete Specification: May 3,

1956 No 13637156. Complete Specification Published: Oct 23, 1957. Index at aceeptance:-Classes 39 ( 3), Hl(D: E: J 2); 66, A( 131: 6 K); and 126, B( 14: 18 89: 43 C), H. International Classification:-A 47 j F 24 b HO 5 b. COMPLETE SPECIFICATION A Hearth Stand I, JAMES KENYON, a British Subject, of 4, Eckersley Road, Bolton, Lancashire, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention concerns hearth stands. The object of the present invention is to provide an improved hearth stand which serves a dual purpose. According to the present invention a hearth stand comprises a strip-like member adapted to be secured into the ground, or a is part of a house foundation and to extend upwardly in abutting relationship with the side of a fireplace, said strip-like member having thereon means for removably securing thereto an attachment such as a "coinpanion set", and at least one ring adapted to be positioned over a fire in the fireplace, or an electric fire and/or fireguard. The invention will be described further, by way of example, with reference to the accompanying drawings in which: Fig 1 is an elevation showing the hearth stand in position, and some of the attachments therefore in position, Fig 2 is an elevation of one alternative attachment, and Fig 3 is a section on the line Ill-Ill of Fig 2. As shown in Fig 1 the stand comprises a strip-like member 10 made from a suitable metal, for example, steel, the member 10 being located, at its lower end in the ground or in a part of the foundations not shown of the house or building having therein a fireplace (generally designated at 11) Secured to the strip 10 in that part adapted to be located in the ground are two strips 12 which are at right angles to the strip 10 and assist in firmly anchoring the strip 10 Intermediate the upper end of the strip 10 and ground 4# or hearth level is a rag bolt 13 which secures the upper end of the strip 10 in abutting re11 Wee 3 r 6 dl lationship with the edge of the fireplace, said bolt being secured into the side of the fireplace, or the brickwork of the chimney breast adjacent the fireplace The bolt 13 also 50 serves to secure in position a plate 14 having hooks 15 thereon upon which can be hung a poker, brush and shovel This latter part being generally known as a "companion set". Above and below the bolt 13 are two cylin 55 drical brackets 16 each of which is adapted to receive a ring 17 carried on an arm 18 The

rings 17 serve as platforms upon which a kettle or pan can be placed over a fire to neat the contents thereof 60 Referring now to Figs 2 and 3 which illustrate an electric fire attachment there is provided a back plate 19 having an overhang part 20 at the top and a box-like lower part 21 The back plate 19 has two apertures 22 65 and 23 therein, one, 22 being rectangular and located near to the overhang 20 The longitudinal edges of this aperture are turned back at right angles to the plate 19 and serve as runners and attaching ledges for a kettle 24 70 The lower aperture 23 is substantially square and has its upper longitudinal edge 25 rollec to form a channel into which the depending edge 26 of a box 27 can be located A lug 28 is located on the face of the plate 19 above 75 the edge 26 of the lower aperture serves to accommodate a peg 29 which is adapted to hold in place a front cover 30 for the box. Across the aperture 22 is an electric element 31 and on the cover 30 is a second electric 80 element 32, suitable cable 33 being provided so that the elements can be plugged into the electricity supply to enable the attachment to be used as an electric fire If the kettle 24 is in place water therein can be boiled, and 85 food placed in the box 27 can be warmed or kept warm. Two cylindrical lugs 34 are provided on the edge of the plate and through these passes a peg 35 whereby the electric fire 90 attachment may be suspended on the brackets 16. The invention is not restricted to the details above described For example, a rod or bar could be secured to the underside of the overhang 20, to extend transversely of the electric fire attachment This bar could be used to support tea towels and the like whilst the latter are being dried. In a further modification a further arm similar to that illustrated at 18 could be secured to the device either above or below the existing arms. In a still further modification a folding clothes horse would be pivotally secured to the plate 14 and be adapted to be located in front of the fire in use or folded against the fireplace when not in use Alternatively the clothes horse could be completely removed for storage.


* GB785277 (A)

Description: GB785277 (A) ? 1957-10-23

Improved method of loosening portable marine structure from a marine bottom


PATENT SPECIFICATION 78 59277 Date of Application and filing Complete Specification: May 15, 1956. > No 151621/56. Application made in United States of America on May 16, 1955. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 68 ( 2), HIE, I 4. International Classification:-E 02 b, d. COMPLETE SPECIFICATION Improved method of Loosening Portable Marine Structure from a Marine Bottom We, DELONG CORPORATION, a Corporation organised and existing under the laws of the State of Delaware, United States of America, of 29 Broadway, New York, State of New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to portable, abovewater marine platforms, which may be in the nature of a dock or in the nature of an offshore installation More particularly, this invention relates to methods of loosening such portable marine structure from a marine bottom in order that it may be moved to another location for re-erection thereat. The marine platform comprises a barge having a buoyant hull equipped with a plurality of extensible upright supporting elements or legs Such legs are caissons which are loosely mounted for vertical movement relative to the hull in corresponding guiding means in the form of wells in the latter. Jacks are mounted on the hull and are releasably engageable with each caisson for forcefully effecting relative vertical movement in either direction between each caisson and the hull, that is, such jacks can

extend or retract the caissons The jacks also can be operated to prevent such relative vertical movement In use of this apparatus, the barge can be floated to any selected marine location and the caissons moved down to engage with the marine bottom while the hull is still afloat Thereafter, by operation of the jacks, the hull can be raised to any desired elevation on the caissons and supported thereon, to thus provide a stable marine platform which can be used as a dock, as a base for drilling operations, or for any other appropriate purpose When it is desired to move the platform to another loca4 S tion, the hull is lowered by the jacks back down into the water until the hull is again lPrice 3 s 6 d J afloat Thereupon, the caissons are pulled up by their jacks out of engagement with the marine bottom and the entire apparatus floated to another erection site 50 Certain problems are encountered in the operation of the aforementioned type of portable, above-water marine platform In particular, such apparatus is presently in use for oil drilling in the Gulf of Mexico, and the 55 marine bottom in certain areas of the Gulf of Mexico, as well as in other locations, is composed for the most part of a deep layer of alluvial mud, that is, a mixture of silt and water overlying harder understrata In its 60 upper portions, the mud layer may contain as much as 80 per cent water, while its deeper parts have small water content Because of the nature of this type of marine bottom, the supporting legs of the aforemen 65 tioned type of above-water marine platform tend to sink deeply into the mud when supporting the weight of the platform and the supplies and equipment carried thereby In fact, when the platform is being erected, each 70 supporting leg is deliberately driven to refusal into the marine bottom in order to prevent settling of any one of the supporting legs deeper into the mud after a prolonged bearing therein In actual practice, support 75 ing legs in the form of tubular steel caissons of the order of 6 feet in diameter have been driven to depths of the order of 70 feet into the marine bottom of the Gulf of Mexico. Because the supporting legs of above 80 water marine platforms of the aforedescribed type are driven deeply into a soft marine bottom, there are problems involved in pulling the legs out of the mud before the platform can be moved to another location When a 85 supporting leg penetrates deeply into a soft marine bottom, the lower portions of the leg tend to become substantially rigid in the mud, so that the latter tends to pack and settle around the legs and substantially 90 freeze the leg in the bottom Hence, in many cases the mud exerts a gripping action on the legs that can be overcome only by a pulling force in excess of the maximum force that can be exerted by a single jack on a stuck leg This situation can also exist even when a supporting leg is equipped with a spread footing When apparatus of the aforedescribed

type is erected in locations where the marine bottom is not particularly soft, a force in excess of that exertable by a single jack may still be required to pull a leg out of the marine bottom A leg may become so stuck in a relatively hard bottom because the leg has been driven thereinto with a piledriving hammer, or the like Furthermore, even in an ordinary mud bottom, wherein a leg does not penetrate very deep, the force required to pull a leg therefrom may become excessive. Additional problems exist in the pulling of a stuck leg other than those encountered by the inherent limitation of the pulling force of any one jack In particular, the imposition of a pulling force on a leg creates an equal and opposite reaction force on the barge or platform In many instances, such reaction force is sufficient to cause the platform to tilt When such a tilting action occurs, the resulting angularity, though small, between the stuck leg and its guide means on the platform tends to cause a binding action between the guide means and the leg Such a binding action renders the pulling of a stuck leg even more difficult Furthermore, the continued application of a pulling force on a stuck leg, when the latter is at the limit of its possible angularity with respect to its guiding means on the platform, imposes a strong bending force on the leg. Such a bending force in many instances may become large enough to actually bend and damage the supporting leg, whether it is in the form of a caisson as described hertofore or in the form of an openwork tower It also is pointed out that the large force sometimes needed to pull a stuck leg also can impose dangerously high stresses in the barge hull. Such streses can be particularly severe when the stuck caisson is located adjacent a corner of a generally rectangular hull, so that the danger of breaking off the corner actually can arise. Consequently, an object of this invention is to provide novel methods for pulling stuck supporting legs of a portable, above-water marine platform, which will avoid a binding action between the legs and their guiding means on a platform, prevent the imposition of excessive bending forces on the stuck leg, prevent the imposition of excessive stresses on the platform, and enable the imposition of a pulling force in excess of the maximum force exertable by the corresponding pulling instrumentality. In order that the disclosure will be more fully understood and readily carried into effect, the following detailed description is given with reference to the accompanying drawings in which: Figure 1 is an enlarged, fragmentary, vertical sectional view illustrating jack mechan 70 ism of the type which can be utilised for practising msthods involving this invention.

The jack is shown mounted on a marine platform and exerting an upward force on a platform-supporting leg 75 Figure 2 is a view corresponding to Figure 1 but showing the jack mechanism exerting a downward force on a platform supporting leg. Figure 3 is an elevational view of an 80 erected, generally triangular, marine platform having three supporting legs, the platform being of the type to which the methods embodying this invention are applicable. Figure 4 is a plan view of the platform 85 shown in Figure 3, with parts broken away to illustrate details. Figure 5 is a perspective view of the platform shown in Figure 3 illustrating the normal result of an attempt to pull one of the 90 platform-supporting legs free of the grip of the marine bottom. Figure 6 is a vertical sectional view taken substantially on line 6-6 of Figure 4 and illustrating a step in one of the methods em 95 bodying this invention. Figure 7 is a view corresponding to Figure 6 but illustrating a step in another of the methods embodying this invention. Figure 8 is a view corresponding to Figure 100 3 but illustrating a rectangular platform having four supporting legs. Figure 9 is a plan view of the platform shown in Figure 8, with parts broken away to illustrate details 105 Figure 10 is a view corresponding to Figure 8 but illustrating a step in a method embodying this invention. Figure 11 is a perspective view of the platform illustrated in Figure 8 showing the nor 110 mal result of an attempt to pull one of the supporting legs free of the grip of the marine bottom. Figure 12 is a vertical sectional view taken substantially on line 12-12 of Figure 9 and 115 illustrating a step of one of the methods embodying this invention. Figure 13 is a view corresponding to Figure 8 but showing the platform lowered back down into the water and afloat before 120 the supporting legs are pulled up from their engagement in the marine bottom. Figure 14 is a view corresponding to Figure 13 but illustrating the normal effect of an attempt to pull up one of the supporting legs 125 free of the grip of the marine bottom. Figure 15 is a plan view of the platform shown in Figure 13 with parts broken way to illustrate details and swng a step in one of the methods embodying this invention 13 C 785,277 785,277 3 Figure 16 is an elevational view of the platform shown in Figure 15. Figure 17 is a plan view of the platform shown in Figure 13 with parts broken away S to illustrate details, and showing a step in one of the methods embodying this invention. Figure 18 is an elevational view of the platform shown in Figure 17.

Figure 19 is a view corresponding to Figure 17 and illustrating a step in one of the methods embodying this invention. Figure 20 is a side elevational view of an erected platform having more than four supporting legs, the platform being of the type to which the methods embodying this invention are applicable. Figure 21 is an end view of the platform shown in Figure 20. Figure 22 is a plan view of the platform shown in Figure 20, with parts broken away to illustrate details. Referring now to Figures 1 and 2 of the drawings, there is shown a jack J mounted on a platform 40, which may be in the nature of a barge having a buoyant hull, for releasable engagement with a platform supporting element or leg L The leg L in this instance is illustrated as a hollow circular steel caisson that is somewhat loosely slidably guided for substantially vertical linear movement relative to the platform 40 in a guiding well 42 that extends vertically therethrough. The guiding well 42 is of a diameter slightly greater than that of the caisson mounted therein so as to somewhat loosely receive and linearly guide the latter In an actual operating embodiment, the caisson is of the order of six feet in diameter uniformly throughout that section of the length thereof receivable in its well, while the latter is about six feet, one inch in diameter Consequently, it will be seen that it is possible for the leg L to cant slightly in its well 42 In Figures 1 and 2 of the drawings, the clearance between the caisson L and its well 42 has been greatly exaggerated for illustrative purposes only. Although all of the supporting legs shown herein have been illustrated as caissons, it is to be understood that this invention is applicable to and may be practised with hulls or platforms having upstanding, supporting legs of any type, whether of an openwork tower-like construction or of the caisson-like construction shown herein Furthermore, it will be realised that the invention can be practised with supporting elements or legs of any suitable configuration in cross section. The jack J is secured to the platform at the well and is disposed in surrounding relation to the leg L The jack shown in Figure 1 and 2 includes vertically spaced upper and lower gripper sections 44 and 46, each comprising a caisson-surrounding rigid collar or sleeve 48 having a plurality of inner circumferential channels which are disposed hollow fluid-pressure-constrictable resilient rings 50 for positively yet releasably gripping the caisson L Between the upper and lower sections 44 and 46 is a caisson -surrounding 70 fluid-pressure-expansible bellows-like section 52 capable of exerting a powerful but controllable force to move the upper and lower jack sections apart, while several pressure-cylinder retractors (not shown) are 75 spaced about and connected to both the upper and lower jack

sections to draw them toward each other when the bellows 52 is exhausted. Abutment means are provided on the plat 80 form 40 to limit both downward movement of the lower jack section 46 relative to the platform and upward movement of the upper jack section 44 relative to the platform In the embodiment of the jack shown 85 herein, the lower gripper section 46 is engageable against the deck of the barge 40, while the upper gripper section 44 is fastened to the barge by a plurality of tie rods 54, usually about four such rods being arranged 90 circumferentially about the jack J The upper gripper section 44 is slidable on the rods 54, but upward movement of such section relative to the rods is limited by heads 56 on the latter engageable by the upper 95 gripper section The connection between the upper gripper section 44 and the rods 54, or the connection of the rods to the platform 40, is such that the entire jack J can move slightly in any transverse direction relative to 100 the guiding well 42 and also can cant with the leg L as the latter cants in its well. Each jack J can be operated to impart step-by-step vertical linear relative movement in either direction between the leg L 105 and the platform 40 Thus, for example, in order to move the leg L upwardly relative to the platform 40, as shown by the upwardly pointing arrow in Figure 1, the lower jack section 46 engages the deck of the platform, 110 the upper jack section 44 is engaged with or grips the leg L, and the bellows 52 is inflated. It further will be realised that if the leg L is stuck in a marine bottom and the jack J is operated, as shown in Figure 1, in an 115 attempt to pull the leg, there will be a reaction force on the platform 40, equal to the force being exerted by the jack on the leg L in an attempt to pull the latter Such reaction force is indicated by the downwardly 120 pointing arrow in Figure 1. When the jack J is being operated to exert a downward force on the leg L to move the latter downwardly relative to the platform 40, as indicated by the downwardly 125 pointing arrow in Figure 2, it will be seen that the upper jack section 44 is engaged against the heads 56 of the tie rods 54 while the lower jack section 46 is engaged with or grips the leg, so that by inflating the bellows 130 785,277 785,277 52 the leg will be forced downwardly relative to the platform Again, there is an opposite reaction force on the platform 40 as indicated by the upwardly-pointing arrow in Figure 2 This operation normally will be carried out only when the leg L is engaged with a marine bottom, and by operating the jack J in the manner shown in Figure 2, the leg will continue to be driven deeper into the marine bottom until the resistance to further penetration of the leg thereinto becomes substantially equal to the force exertable on the leg by the jack

without lifting the platform. When a plurality of legs are engaged with a is marine bottom and have been so driven to refusal, continued operation of the jacks in the manner shown in Figure 2 will serve to raise the platform on the legs. It also will be seen that the jack J can be operated to prevent any relative vertical movement between the leg L and the platform 40 In this operation the upper section 44 is engaged with the tie rod heads 56 and the leg L and the lower section 46 is engaged with the deck of the platform 40 and the leg. Normally, the bellows 52 will be fully inflated to so position the jack sections 44 and 46 Controls (not shown) are provided for a plurality of jacks to enable their selective individual operation or their operation in unison. It also is pointed out that other types of jacks which operate on somewhat the same general principles as the above described jack can be employed for practising this invention Additionally, the methods of this invention can be practised with other types of mechanisms for forcefully moving upright supporting legs vertically in either direction relative to a platform or for restraining such movement, so that the practice of this invention is not necessarily limited to the employment of a jack type of apparatus for forcefully effecting relative vertical movement between a supporting leg and a platform It is pointed out, however, that the amount of movement-effecting force developed by any moving instrumentality is inherently limited by the size of the moving instrumentality and that economy dictates a limitation on the size of any moving instrumentality. PLATFORM HAVING THREE SUPPORTING LEGS. Referring now to Figures 3 and 4 of the drawings, there is shown a portable marine platform of the type with which this invention is concerned In this instance, the apparatus is shown as a generally triangular buoyant platform 58 having three supporting legs LI, L 2, and L 3, in the form of caissons, extending through corresponding guiding wells in the platform and operated by corresponding jacks J 1, J 2, and J 3 of the aforedescribed type The supporting legs L are located at the corner portions Cl, C 2, and C 3 of the platform 58 in order to provide stable support for the latter when it is in its erected position shown in Figure 3 wherein the supporting legs L have engaged and penetrated at various depths into a marine bottom 60 and the platform has been 70 elevated above the surface 62 of the water by operation of the jacks J As stated heretofore, certain marine bottom conditions, such as these existing in the Gulf of Mexico, require the legs L to penetrate quite deeply 75 into a marine bottom before they reach a bearing sufficient to support the weight of the platform when the latter has been elevated out of the water sufficiently to

eliminate or substantially eliminate its buoyancy 80 support, and such deep penetration is shown in Figure 3. When it is desired to move the erected platform 58 to another location, the problem arises of pulling the supporting legs L loose 85 from the marine bottom 60 As previously described, no upward pull can be exerted by a jack J on its corresponding supporting leg L without exerting an equal and opposite downward reaction force on the platform 58 90 In the present instance, when the platform 58 is elevated out of the water, as shown in Figure 3, and an upward pull is exerted on any one leg L by its jack J, the resulting downward reaction force on the platform 95 will be substantially unopposed, because the platform is supported at only two other locations, i e, by the other two legs The result will be to tilt the platform 58 Hence, if a platform is of generally triangular configura 100 tion and has only three supporting legs, i e, one at each corner, the platform must be lowered back down into the water for buoyancy support before the supporting legs can be pulled up 105 When the platform 58 has been so lowered by the jack J and is afloat, the normal manner of pulling up all of the legs L from the marine bottom is to operate all of the jacks in unison Before this is done, however it 110 is desirable to assure that each leg L can be pulled loose from the marine bottom 60 withiout the use of an excessive pulling force. Hence, the first step is to operate each jack J in succession in a direction to pull its cor 115 responding leg L slightly If each leg L can be moved up slightly by its jack J, without the corresponding reaction force causing the platform 58 to tilt excessively, the next operation preferably will be to operate all of 120 the jacks individually until the lower ends of the deeper penetrating legs, i e, LI and L 2 as shown in Figure 3, are on substantially the same level as the lower end of the shallowest penetrating leg, i e, L 3 All of 125 the jacks usually are then operated in unison to pull up all of the legs L at the same rate so that the lower ends of the latter will clear the marine bottom 60 at substantially the same time Hence, the platform 58 can float 130 and the platform 58 to hold the platform in a stationary position That is, the jacks J are operated to prevent the corner portion Cl of the platform from bobbing up unduly and thus tilting the platform sufficiently to 70 cause possible damage to the legs L and/or their wells While the platform 58 is held in such a stationary position the water ballast is then unloaded from the tanks T 2 and T 3 or evenly distributed among all the tanks 75 T and the jacks are then operated to level the platform if it is out of level Thereupon, all of the jacks J are operated in unison to control the rise of the platform 58 to its normal draft, as indicated, for example, by the 80 dotted line 64 in Figure 6, as the tanks T are

pumped dry After its normal draft 64 has been reached, the jacks J are operated to pull all the legs L clear of the marine bottom 60 as described hereinbefore in order to 85 float the apparatus to another erection site. During the course of the foregoing operation of freeing the leg L 1 from the grip of the marine bottom 60 thereon, it will be seen that the pulling force exerted by the jack J 1 90 is opposed primarily by the buoyancy of the corner tank TI As stated heretofore, however, the pulling force exertable by any one jack J on its leg L is inherently limited by the size of the jack Consequently, the maxi 95 mum pulling force exertable by the jack J 1 on the leg L 1 may be insufficient to loosen the latter in the marine bottom 60 Additionally, this force normally is not great enough to force the corner Cl of the plat 100 form 58 down into the water to any great extent below the normal draft 64 of the platform 58 In this connection, the tilt-down of the corner Cl shown in Figure 5 has been greatly exaggerated for illustrative purposes 105 only Of course, as the corner Cl is forced deeper and deeper into the water, more and more of the latter is displaced so that the buoyancy force opposing the fulling force of the jack J 1 correspondingly increases 110 Hence, at the maximum pulling force exertable by the jack J 1 without loosening the stuck leg Ll, normally there still will be a considerable amount of freeboard at the corner of the platform 58 Il S In such an event, wherein the maximum pulling force of the jack J 1 is insufficient to free the leg L 1 by the aforedescribed procedure, this invention also provides a method whereby a pulling force in excess of that ex 120 ertable by the jack J 1 may be imposed upon the stuck leg L 1 in an effort to loosen the latter from the marine bottom 60 For this purpose, all of the jacks J are disengaged from their respective leg L and all of the 125 tanks T are slowly flooded substantially equally to sink the platform 58, while maintaining it level, deeper in the water until a substantially minimum uniform freeboard is obtained as shown in Figure 7 At this point, 130 free without being pinned to the bottom 60 by any one leg L Thereafter, the entire apparatus can be floated, as by a tug (not shown) to another erection site. In many instances, however, it will be found that a leg, e g Ll, will be gripped so tightly in the marine bottom 60 that the reaction force developed by independent operation of its jack J 1 in an effort to pull it loose will merely force the corresponding corner portion Cl of the platform 58 lower into the water as is shown in Figure 5 This forceful tilting of the platform 58, if continued, not only eventually will cause all the legs L to become tightly bound in their wells or other equivalent guides, but also obviously will exert a strong bending force on all the legs Hence, as previously pointed out,

continued efforts to pull a stuck leg by its jack might possibly severely damage all the legs as well as impose dangerous stresses on all the guiding wells and those portions of the platform adjacent thereto. The aforedescribed difficulties can be avoided, however, by the methods embodying this invention One of such methods involves counterbalancing the platform 58 so that it will remain on an even keel, i e substantially level in the water, while a strong upward pull is being exerted upon the stuck leg L 1 by its jack J 1 This levelling of the platform 58 can be accomplished by releasing the jacks J 2 and J 3 on the legs L 2 and L 3, and slowly adding weight to that portion of the platform remote from the leg Li, i e, the portion between the legs 2 and L 3, in a manner to cause that portion to sink deeper in the water and maintain the platform substantially level as the corner Cl tends to be pulled down while the jack J 1 is being operated to pull the stuck caisson Li This added weight may take the form of heavy equipment, e g, a crawler crane, portable air compressors, or the like (not shown, carried in some instances upon such a platform, which can be shifted to the general area between the two legs L 2 and L 3 to counteract the tilting effect caused by the reaction force of thl jack J 1 on the platform 58 In the event So that such heavy equipment will not be available or will not be heavy enough, the platform 58 can be prefabricated with a number of interior buoyance tanks, such as the three tanks TI, T 2, and T 3 shown in Figure 4, and by controllably flooding the tanks T 2, and T 3, sufficient weight can be added slowly to that portion of the platform 58 opposite the corner Cl to maintain the platform level, as shown in Figure 6, while the jack J 1 is being operated with increasing force in an attempt to free the stuck leg Li. When the stuck leg L 1 starts to come loose, all of the jacks J are immediately actuated to grip their legs L and restrain relative vertical movement between the latter 785,277 the jack J 1 is engaged with the stuck leg L 1 to restrain any relative vertical movement between the latter and the platform 58, and water is slowly pumped from the tank T 1. As the tank T 1 is slowly emptied of water, the corner portion Cl of the platform becomes more and more buoyant, and eventually a buoyancy force will be obtained in excess of the maximum pulling force exertable by the jack J 1 This buoyancy force normally will be sufficient to loosen the leg L 1 from the marine bottom 60 In this connection, it will be seen that water is allowed to remain in the tanks T 1 and T 2 so that the platform 58 will not tilt during the deflooding of the corner tank Ti Such tilting possibly would occur even if the jacks J 2 and J 3 were engaged with their legs L 2 and L 3 because the latter are assumed to be loose, i e, not stuck, in the

marine bottom 60. As soon as the leg L 1 starts to break loose in the marine bottom 60, the tanks T 2 and T 3 are started to be de-flooded to prevent tilting of the platform 58 Additionally, at this time, all of the jacks J are appropriately operated to exert opposed forces between their respective legs L and the platform 58 to control the latter while it is rising due to its increased buoyancy In other words, as the tanks T 2 and T 3 are being de-flooded, all the jacks J must be operated to maintain the barge 58 substantially level, until all of the tanks T have been de-flooded and the barge is at its normal draft 64 and in a level position Were the platform 58 allowed to tilt appreciably during the foregoing procedure, possible damage to the legs L or to the structure of the platform obviously could occur. It will be seen that in some instances, more than one of the legs L might be stuck quite tight in the marine bottom 60 In theevent that it is found that all of the legs are so stuck, after the platform 58 has been lowered back down into the water until it is afloat, all of the jacks J can be operated in unison to the maximum extent of their pulling force in an effort to free the stuck legs. This simultaneous pulling operation of all So the jacks J obviously will force the entire platform 58 deeper into the water while maintaining it substantially level Consequently, if one of the stuck legs L starts to break loose, all of the jacks J must be operated in a manner to maintain the platform 58 on an even keel, while the jacks J are being operated to allow the platform to rise on the legs to its normal draft 64. If the foregoing procedure does not loosen any or all of the three stuck legs L, the jacks J can be disengaged from the legs and all three tanks T evenly flooded until the platform 58 has sunk to a minimum freeboard, as shown in Figure 7 Thereupon, the jacks J are re-engaged with the legs L to restrain any relative vertical movement between the latter and the platform and all the tanks T are evenly and slowly de-flooded By this procedure a buoyancy pulling force can be developed on each of the three stuck legs 70 normally greatly in excess of the pulling force exertable by any one of their jacks J. Again, if any one of the three stuck legs L starts to break loose in the marine bottom 60, all the jacks J must immediately be 75 operated in a manner to maintain the platform 58 level. Assuming that one of the three stuck legs L has been loosened so that it can be pulled up readily by the operation of its jack J, 80 there will remain two legs stuck in the mud. Thus, for example, assuming that leg L 1 has been loosened and that legs L 2 and L 3 remain stuck, the latter two legs can be loosened by procedures similar to those out 85 lined hereinbefore First of all, an

attempt can be made to free either or both of the two stuck legs L 2 and L 3 by exerting simultaneous pulling forces thereon by their respective jacks J 2 and J 3 To avoid tilting 90 of the platform 58, the jack J 1 is released and weight slowly added to the corner portion Cl of the platform, as by flooding the tank Ti, to cause such portion to sink deeper into the water and thus maintain the entire 95 platform 58 substantially level as the two corner portions C 2 and C 3 are being forced deeper into the water by the reaction force exerted thereon by the jacks J 2 and J 3 in their efforts to pull the two stuck legs L 2 and 100 L 3 If either or both of the two legs L 2 and L 3 are loosened in the marine bottom 60 by this procedure, the tank T 1 is immediately started to be de-flooded to prevent tilting of the platform Also, as the corner Cl 105 tends to rise because of its increasing buoyancy, all of the jacks J are operated in a manner to cause the platform 58 to rise to its normal draft 64 without becoming appreciably out of level 110 If the aforedescribed procedure fails to loosen the two stuck legs L 2 and L 3, all of the jacks J can be released, and all of the tanks T flooded substantially equally to thus sink the platform 58 deeper into the water 115 until it has substantially minimum freeboard At this time, the jacks J 2 and J 3 are operated to restrain relative vertical movement between the platform 58 and the legs L 2 and L 3 and the two tanks T 2 and T 3 are 12 a slowly de-flooded Thus, the buoyancy of the two corner portions C 2 and C 3 will slowly increase until an upward pulling force is exerted on the two stuck legs L 2 and L 3 in excess of the maximum pulling force ex 125 ertable thereon by their respective jacks J 2 and J 3 As previously stated, such force normally will be sufficient to loosen either or both of the stuck legs L 2 and L 3 in the marine bottom 60 Again, when either or 13 ( 785,277 by the marine bottom 68, so that the aforedescribed testing procedure merely serves to force down the corresponding corner C of the platform 66 when the leg-pulling force of the jack J begins to overcome the afore 70 described counterbalancing effect of the diagonally opposite corner portion and leg thereat In such an event, the following procedure may first be attempted in order to try to free a stuck caisson 75 First of all, all of the loosened legs L are driven back down to a firm bearing into the marine bottom 68 by operation of their jacks J Thus, for example, assuming that leg Li is stuck and the remaining legs L 2, L 3, and 80 L 4 are loose, after the aforedescribed testing procedure the latter legs L 2, L 3, and L 4 are driven back to a firm bearing, i e, their original bearing, in the marine bottom by their respective jacks J Thereupon the 85 jacks on the legs L 2, L 3, and L 4 are engaged with their legs in a manner so that no relative vertical movement can occur between the three legs L 2, L 3, and L 4 and the

platform 66 The jack J 1 for the stuck leg L 1 90 then is operated to exert a pulling force on the latter, with the consequent development of an equal downward reaction force on the corner portion Cl of the platform 6 This reaction force, which obviously urgesthecor 95 ner portion Cl downwardly, is opposed primarily by the support afforded by the two legs L 2 and L 4 so that the reaction force also tends to raise the diagonally opposite corner portion C 3 of the platform 66 If the 100 leg L 3 holds fast in the marine bottom 68, the platform 66 will not tilt, but if the leg L 3 pulls loose from the marine bottom, and it is assumed to be loose therein, the corner Cl will drop and the corner C 3 will rise, and 105 thus tilt the platform as shown in Figure 11. As aforedescribed, such a condition is highly undesirable, because all the legs L will immediately start to bind in their wells as soon as the limit of angularity between each leg 11 O and its well is reached This binding action serves to reduce the effective pulling force exertable on the leg L 1 by its jack J 1 and also to impose strong and possibly damaging bending forces on all the legs and possibly il S damaging stresses on their wells and associated platform structure. In order to eliminate the aforedescribed tendency of the platform 66 to tilt if the leg L 3 pulls loose, weight is added slowly to the 120 opposite corner portion C 3 of the platform, as the pulling force of the jack J 1 is increased, in order to counterbalance such tilting effect As described before, such weight can take the form of heavy equipment (not 125 shown) which can be shifted to the corner C 3 In the event that the weight of such equipment is not sufficient to counterbalance the tilting tendency or such equipment is not available or shiftable, it is desirable for the 130 both of the two stuck legs L 2 and L 3 start to break loose in the marine bottom, the tank T 1 is started to be de-flooded and all of the jacks are operated to maintain the S platform 58 substantially level while it rises to its normal draft 64. PLATFORM HAVING FOUR SUPPORTING LEGS. Referring now to Figures 8 and 9 of the drawings, there is shown another type of portable marine platform embodying apparatus with which this invention is concerned. In this instance, the apparatus is shown as a generally rectangular buoyant platform 66 having four supporting legs LI, L 2, L 3, and L 4, one located adjacent each corner portion Cl, C 2, C 3, and C 4, in the form of caissons extending through corresponding guiding wells in the platform and operated by jacks J 1, J 2, J 3, and J 4 of the aforedescribed type The platform 66 is shown erected in Figure 8 wherein the supporting legs L have engaged and penetrated at various depths relatively deeply into a soft marine bottom 68, and the

platform has been elevated above the surface 70 of the water on the legs by operation of the jacks J. As hereinbefore described with reference to a three-legged triangular platform, when the platform 66 is to be moved to another location, it is desirable to assure that each leg L can be pulled up easily out of the marine bottom 68 before all the legs are raised in unison as described hereinbefore. When a platform is supported by more than three legs, such initial procedure can be accomplished before the platform is lowered back down into the water into its floating condition This is highly desirable since it shortens the time of transition of the apparatus after the platform is in the water from its bottom-pinned to its free floating condition, which shortened transition time is greatly advantageous if heavy seas are running Hence, before the platform 66 is lowered back down into the water by operation of the jacks J, each jack can be operated in succession in a direction to pull its corresponding leg L slightly because the platform will be substantially stably supported by the SO other three legs In other words, the reaction force of any one jack J, if not excessive, will not force down the corresponding corner C of the platform 66 because of the counterbalancing weight of the diagonally opposite corner portion and the weight and bottom-grip on the leg thereat when the jack of the latter restrains vertical movement of the same relative to the platform. If a leg L can be moved up slightly by its jack J, the leg will be able to be pulled up completely by its jack when the platform 66 is lowered back down into the water Frequently, however, the aforedescribed testing procedure will reveal that one, or possibly more, of the legs L is gripped tightly 785,277 platform to be provided with interior compartments or tanks T, as shown in Figure 9, into which water can be pumped for adding weight thereto Hence, as is shown in Figure 12 of the drawings, sufficient water has been added to the tank T 3 to counteract the tendency of the platform 66 to tilt when the jack J 1 is being operated in a direction to pull the stuck leg Li Thereupon, a large pulling force can be exerted effectively by the jack J 1 in an effort to loosen the leg L 1 in the marine bottom 68. It is obvious that the foregoing procedure will exert large stresses in the platform 66, and if the latter does not possess sufficient structural strength, there actually may be a danger of breaking off the corner portion Cl. Hence, if the platform 66 cannot safely absorb the stresses imposed therein when the jack J 1 is operated with its maximum pulling force, the latter must be operated with a reduced force. Even when the jack J 1 is operated with its maximum pulling force in an effort to loosen the stuck leg L 1 by the foregoing procedure, in

some instances such procedure will not serve to loosen the stuck leg In that event, the following procedure may next be employed, assuming that the platform 66 has sufficient structural strength to enable the employment of such procedure. The jack J 1 is engaged with the leg Li, to prevent relative vertical movement between the latter and the platform 66, and 3 g simultaneously the jacks on the other three legs L 2, L 3, and L 4 are operated in a manner to lift the platform 66 on such legs By means of this procedure, it will be seen that the combined forces of all three jacks J 2, J 3, and J 4 can be utilised in an effort to loosen the stuck leg Li If the combined lifting forces of the jacks J 2, J 3, and J 4 fail to loosen the stuck leg Li, the jack J 1 of the latter is operated to exert a pulling force on the leg L 1 while the other three jacks are being operated to exert liftinn forces on the plattorm 66 Thus, the combined efforts of all four jacks can be emn Dloved to loosen the leg Li It will be realised, However that the upward forces so exertable on the leg L 1 through the platform 66 by the jacks J 2, J 3, and 34 are limited by the weight of the platform Of course, both of these procedures exert tremendous stresses in the platform 66 SS so that due regard must be had to its structural strength Additionally, the platform 66 may also have a tendency to tilt downwardly at the corner Cl and to rise at the opposite corner C 3 during such procedures Such a tendency also can be restrained by the hereinbefore described counterbalancing steps, e.g by pumping sufficient water into the tank T 3 to counterbalance the pulling force on the leg Li. The aforedescribed procedure of utilising the combined force of all of the jacks J to loosen a single leg can also be employed if all, or any lesser number, of the legs are stuck in the marine bottom 68 by operating on each stuck leg in succession Although 70 the foregoing procedure of utilising the combined force of all of the jacks J to loosen a single stuck leg L is possible, marine platforms of the type under consideration normally are not designed to withstand such ex 75 treme stresses The imposition of such extreme stresses can be avoided, however by lowering the platform 66 back down into the water until it is afloat at normal draft 72, as shown in Figure 13, and then utilising the 80 following procedures in an effort to free stuck legs. Assuming that leg Li is stuck in the marine bottom 68 and that the remaining legs L 2, L 3, and L 4 are loose therein, the 85 exertion of a pulling force by the jack JI on the stuck leg Li, with the remaining jacks J 2, J 3, and J 4 disengaged from their respective legs, serves to force the corner Cl deeper into the water with a resulting undesirable 90 tilting of the platform 66, as exaggeratedly shown in Figure 14 The tendency of the platform 66 to so tilt can be avoided, however, by the hereinbefore described procedures of adding sufficient

weight to the 95 diagonally opposite corner C 3, as by slowly flooding the tank T 3 as shown in Figure 15, to maintain the platform level as shown in Figure 16 as the pulling force of the jack J 1 is increased and forces the corner Cl deeper 1 i O in the water It will be seen that during this procedure, the platform 66 is supported in the water by the uniform pressure of the latter thereagainst, and that the downward reaction force of the jack J 1 is opposed prim 1 (S arily by the buoyancy of the corner portion Cl of the platform so that no concentrated and damaging stresses are imposed on the latter by such procedure During this procedure the tanks T 2 and T 4 can be flooded 110 selectively and partially, if need be, in order to counteract any tendency of the nlatform to tilt down at the opposite corner C 4 or C 2. respectively. If by this procedure, the leg L 1 starts to 115 pull loose, the remaining jacks J 2 J 3, and J 4 are immediately operated to restrain vertical movement between the legs L 2, L 3, and L 4. while the tank T 3 is de-flooded, and also the tanlks T 2 or T 4, if also flcoded Thereupon, 120 the jacks J are operated to level the platLorm 66 if necdssarv, and to control the rise of the platform to its normal draft 72. If all or more than one of the legs L is stuck in the marine bottom attempts can be 125 made to free such legs bv operating on them in succession in accordance with the foregoing procedure Still another procedure can be utilised, however When the platform is afloat, the jacks for such stuck legs can be 130 785,277 and T 2 are slowly de-flooded. PLATFORM HAVING MORE THAN FOUR SUPPORTING LEGS. Substantially all of the foregoing procedures are likewise applicable to marine plat 70 forms of the type under consideration having more than four supporting legs Thus, for example, as shown in Figures 20 to 22, a generally rectangular marine platform 74 may have twelve such supporting legs Li to 75 L 12 arranged in two rows extending along both longitudinal sides of the platform. When the platform 74 is in its erected position, as shown in-Figures 20 and 21, with the legs L penetrating at various depths into the 80 marine bottom 76, each leg is first tested by its jack J to see if it can be loosened in the marine bottom before the platform is lowered back down into the water Such testing procedures were outlined hereinbefore 85 with reference to the platform shown in Figure 8. In this connection, it will be seen that the maximum pulling force of each jack J can be exerted on its corresponding leg L with 90 substantially no possibility whatever of causing the platform 74 to tilt because of the geometrical arrangement of the legs on the

platform Even if the maximum pulling force of the jack J is exerted on a corner leg, such 95 as leg Li, it will be seen that any tendency of the corresponding corner of the platform 74 to be pulled down, because of the resulting reaction force on the platform, will be completely counteracted by the weight of 100 those portions of the platform on the opposite side of a line, connecting the legs L 2 and L 3, from the leg Li. In the event, however, that a leg L is stuck so fast in the marine bottom 76 that the 105 maximum pulling force of its jack J is insufficient to loosen the leg, the following procedure can be used to exert a pulling force on the stuck leg in excess of the pulling force exertable thereon by its jack 110 Thus, for example, assuming that the leg LI cannot be freed from the marine bottom 76 by its jack J 1, the latter jack is engaged with its leg L 1 to prevent downward nmovement of the latter relative to the platform 74 a 115 and then all of the other jacks J 2 to J 12 are operated to lift the platform on the legs L 2 to L 12, thus utilising the combined force of eleven of the jacks J in an effort to free the stuck leg Li Of course, as heretofore men 120 tioned, the combined force of the aforementioned eleven jacks J 2 to J 12 effective to pull the stuck leg Li is limited somewhat by the weight of the platform 74 and the equipment carried thereon and therein Nevertheless, 125 the aforementioned combined force normally is greatly in excess of the pulling force of any single jack J If the foregoing procedure is not successful in freeing the stuck leg Li, the jack J 1 on the stuck leg can be operated to 130 operated in unison to exert pulling forces on the stuck legs while counterbalancing any tilting tendencies of the platform 66 by adding weight to appropriate portions of the S platform as described hereinbefore with reference to a three-legged platform Thus, for example, if the legs LI and L 2 are stuck, while their jacks J 1 and J 2 are being operated in unison to pull them, the tanks T 3 and T 4 are flooded sufficiently to maintain the platform 66 level as that side of the platform extending between the corner Cl and C 2 sinks deeper in the water. As aforedescribed, the maximum pulling force exertable by a single jack on its leg in many instances will be insufficient to loosen a leg that is stuck in a marine bottom Accordingly, if the foregoing procedure is unsuccessful, the following procedure may be utilised in an attempt to free a stuck leg, e g, Li All of the jacks J are disengaged from their legs L and all of the tanks T are slowly and uniformly flooded as shown in Figure 17 until the platform 66 has sunk into the water to a minimum freeboard, as shown in Figure 18 At this point the jack JI is operated to grip or engage its leg Li in a manner to prevent relative vertical movement between the latter and the platform 66 The tank TI then is slowly de-flooded, as shown in Figure

19, so that the increased buoyancy of the corner portion Cl of the platform 66 will exert an upward pulling force on the stuck leg Ll in excess of that exertable thereon by the jack J 1 In the event that this buoyancy force is insufficient to loosen the leg Li, the tanks T 2 and T 4 may be slowly and controllably de-flooded, in a manner to prevent tilting of the platform 66 toward either of the corners C 2 or C 4, to resultingly increase the upward buoyant force on the leg Li If necessary, additional water can be pumped into the tank T 3 to prevent upward tilting of the corner C 3 because of the increasing buoyancy of the tanks T 2 and T 4. The foregoing procedure, i e, first deflooding tanks T 3 and then de-flooding tanks T 2 and T 4, if necessary, usually will be quite sufficient to loosen the stuck leg Li As soon as the leg Li starts to loosen in the marine bottom, the tank T 3, and T 2 and T 4 if flooded, is controllably de-flooded and all of the jacks J are operated on their legs to maintain the platform 66 level while it is rising due to its increasing buoyancy. Similar procedures can be employed to free more than one stuck leg, either by operating on them in succession, or in unison as described hereinbefore with reference to a three-legged platform Thus, for example, if the legs Li and L 2 are stuck, after the platform 66 has been sunk to a minimum freeboard, the jacks J 1 and J 2 are operated to restrain downward movement of their legs relative to the platforms while the tanks TI 785,277 pull the leg Li while all of the other eleven jacks J 2 to J 12 are being operated in a manner to lift the platform. Of course, the employment of the foregoing procedure is limited by the structural strength of the platform 74, and in particular if a corner leg Li, L 2, Lii, or L 12 is stuck, there may be some danger of actually damaging the structure of the platform by any of the foregoing procedures Accordingly, if any of the foregoing procedures do not succeed in freeing a stuck leg by exerting pulling forces thereon to the maximum extent permitted by the structural strength limitations of the platform 74, the platform should be lowered back down into the water 78 until it is afloat, and the following procedures employed. Again, assuming that leg L 1 is stuck in the marine bottom 76, the jacks J 2 to J 12 are released and the jack J 1 is operated to exert a pulling force on the stuck leg As the pulling force of the jack JI is increased, the resulting reaction force will tend to force the corner portion Cl of the platform 76 deeper into the water To counteract this tilting of the platform 74 and to maintain it on an even keel while the jack J 1 is being operated in an effort to free the stuck leg Li, weight is added or shifted to the opposite side of the platform Thus,

for example, the ballast tanks T 2 and T 4 may be partially flooded sufficiently to maintain the platform on an even keel athwartship If necessary, the tanks Ti 1 and T 12 may also be sufficiently partially flooded in order to maintain the platform on an even keel fore and aft or longitudinally. Much the same procedures may be followed in the event that a leg remote from a corner of the platform is stuck Thus, for example, assuming that leg L 6 is stuck in the marine bottom, while the jack J 6 is being operated in an effort to free the stuck leg L 6 weight must be shifted or added to the other side of the platform in order to maintain the latter on an even keel athwartship. Hence, the tank T 5 may be sufficiently partially flooded to maintain such an even keel. It is obvious that when a stuck leg is located at a position remote from the ends of the platform 74, there usually will be no necessity for flooding any of the end tanks to maintain the platform 74 on an even keel longitudinally When a stuck leg starts to pull loose, all of the jacks are immediately operated to engage their corresponding legs in order to hold the platform 74 stationary while the interior tanks which were flooded are de-flooded and then all of the jacks are operated to maintain the platform on an even keel while it rises to its normal draft. If any of the foregoing procedures do not succeed in freeing a stuck leg, the following procedure may then be followed A number of symmetrically disposed tanks, such as the tanks Ti, T 2, Til, and T 12 are slowly and evenly flooded until the platform sinks levelly into the water to a minimum freeboard If necessary, additional tanks, such 70 as tanks T 3, T 4, T 9, and T 10 may also have to be flooded in order to obtain such a minimum freeboard After such a minimum freeboard is had, the jack for the stuck leg is then operated to engage therewith Thus, 75 for example, assuming that leg L 1 is stuck in the marine bottom, the jack J 1 is engaged therewith, while the other jacks are disengaged from their respective legs, and the tank Ti then is slowly de-flooded so that the 80 increasing buoyancy of the corner Cl of the platform exerts a progressively increasing upward force on the stuck leg Li Additional tanks, such as T 2 and T 3, also can be slowly de-flooded in the event that the buoy 85 ancy force of the tank Ti is insufficient to free the stuck leg Li from the grip of the marine bottom 76 In the event that the platform tends to tilt in any direction during the foregoing operation, other tanks may be 90 flooded or de-flooded as necessary in order to maintain the platform level As before, when the stuck leg Li starts to break loose from the marine bottom, all of the jacks are operated to grip their respective legs L in 95 order to hold the platform stationary while the tanks T

which had been flooded are deflooded Thereupon, all of the jacks are operated to control the rise of the platform to its normal draft 100 If more than one leg is found to be stuck in the marine bottom, they can be freed by operating on them in succession in accordance with the foregoing procedure, or in unison in accordance with comparable proce lo S dure hereinbefore with reference to threelegged and four-legged platforms. It will be realised that all of the foregoing methods can be practised with non-buoyant platforms that are detachably carried, 110 for example, on a barge and have the supporting legs of the platform disposed outboard of the peripheral outline of such barge for effective operation of such legs Those methods described above wherein the plat 115 form is afloat while a stuck supporting leg is being pulled, still can be practised with a non-buoyant barge-carried platform by securely fastening the latter to the barge Of course, in all of those methods wherein a 12 C stuck leg is being pulled while the platform is above the water, the platform can be nonbuoyant and the barge used only for installation and transportation of the platform.


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