MACHINE PISTOL HAVING HYDRAULIC BREECH' LOCKING ANDv OBTURATION

Filed Jan. 27, 1966

.Aug.~22,19s7 ‘c. L. WILSON 3,336,838

INVENTOR C'Zzrz‘zk J. Wilson

United States Patent .0 1

3,336,838 MACHINE PISTOL HAVING HYDRAULIC BREECH

LOCKING AND OBTURATION Curtis L. Wilson, 3103 Elizabeth, Space 25,

Pueblo, Colo. 81003 Filed Jan. 27, 1966, Ser. No. 523,474

2 Claims. (Cl.'89-197)

ABSTRACT OF THE DISCLOSURE A machine pistol having a spring loaded, divided bolt

locked and obturated by hydraulic pressure. The bolt sections have enlarged mating heads with bores there through which align when one of the bolt sections is ro tated to relieve hydraulic pressure and permit manual retraction of the bolt sections.

This invention relates to a machine pistol and more particularly to an automatic ?rearm employing hydraulic breech locking and obturation.

Brie?y, the invention consists of a spring loaded di - vided bolt normally locked and obturated in a closed, ?ring position by pressure of hydraulic ?uid in a cham ber in the receiver body of the weapon. The ?uid further acts as a recoil buffer. The bolts have enlarged mating heads having bores therethrough. By rotating one of the bolt sections, the bores are aligned to relieve hydraulic pressure thereon whereby the bolt may be easily retracted by hand. i 7

It is a primary object of this invention to provide an automatic ?rearm in which the bolt mechanism is locked and obturated by hydraulic pressure.

It is another object to provide means in the bolt mech anism whereby the bolt may be retracted easily by hand. A further object is to provide means for adjusting the

hydraulic pressure in the hydraulic ?uid chamber so as to automatically relieve the hydraulic pressure upon re coil of the bolt. A still further object is to provide an automatic weapon

that does not depend upon mechanical lugs to obturate vthe breech mechanism thereby eliminating wear and necessary replacement of the bolt mechanism.

These and other objects and advantages of the present invention will be fully apparent from the following de scription when taken in connection with the annexed drawing, in which: FIG. 1 is a somewhat schematic axial section view of

the weapon of the invention showing the bolt mechanism in locked position; FIG. 2 is a similar view showing the bolt mechanism

in full recoiled position; I .

FIG. 3 is a cross sectional view taken along line 3-3 of FIG. 1; FIG. 4 is a perspective view of the forward bolt sec

tion; .and, FIG. 5 is a perspective view of the rearward bolt sec

tion. With reference to'the drawing in detail, wherein like

reference numerals indicate like parts throughout the several views, numeral 1 indicates generally the pistol of the- invention. As shown in FIGS. 1 and 2, only the operating ele

ments essential for illustrating the invention are shown. Such elements or mechanisms as the stock, ?ring means, trigger, ejecting means are not shown since they consti tute no part of this invention, the invention being in the bolt mechanism per se. The pistol 1 includes a receiver body 2 and a barrel 3

which is attached to body 2 by threads 4. Barrel 3 is pro

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3,336,838 Patented Aug. 22, 1967

2 vided with a bore 5, and a ?ring chamber 6 at its breech end. ‘

Receiver body 2 is provided with a central bore 7 which extends completely therethrough. A counterbore 8 is provided substantially midway of bore 7 and forms a chamber 9 for hydraulic ?uid. A second smaller coun terbore 10 is provided as shown for a purpose to be de scribed later. A threaded plug 11 is provided to close the rearward

end of bore 7. , An opening 12 in the forward end of body 2 receives

a conventional magazine 13 which contains rounds 14. One round is shown in FIG.‘ 1 in the ?ring chamber 6. The vbolt mechanism comprises a forward bolt section

15 and a rearward bolt section 16. Forward bolt section 15 carries the cartridge case ejector and the ?ring pin. both not shown. Bolt 15 is provided at its rearward end with an enlarged head 17 which is perforated with lon~ gitudinally spaced relief bores 18.

Bolt 16 is also provided with an enlarged head 19 and similar bores 20*.

Bolts 15 and 16 slide in bore 7 and heads 17 and 19 slide in counterbore 10. Bolt 16 may be prevented against rotation as by a key 21 which rides in a keyway 22.

Bores 18 and 20 are circumferentially spaced in heads 17 and 19 respectively and will register when the head 17 is rotated one eighth of a turn. Eight bores are shown in each head. More or less can be provided as expedient for the e?icient operation of the bolts. ‘ ' A bolt spring 23 in chamber 9 and encircling bolt sec tion 16 normally urges bolt section 16 forwardly to closed position for ?ring. Means for rotating bolt section 15 to align bores 18

with bores 19 for easy retraction of the bolt sections manually are provided and may consist of a handle 24 attached to bolt section 15 and extending through the ejecton slot 25. Means for relieving the hydraulic pressure in body 2

to permit full recoil of the bolt sections are provided and comprise a bore 27 extending for a length therein and a port 28 extending between bore 27 and chamber 9 as shown. A threaded pressure plug 29 is threada‘bly mount ed in the rearward end of bore 27 and a plunger 30, nor mally urged forwardly in bore 27 by a spring 31 com plete the assembly. A plug 32 of compressible material, such as soft rub

ber, is mounted in central bore 7 between the rearward end of bolt section 1.6 and closure plug 11 to form a seal therebetween.

' Operation

The pistol 1 is shown in its position for ?ring in FIG. 1 and bores 18 and 20 in heads 17 and 19 are in o?set relation. Chamber 9 is ?lled with a hydraulic ?uid and some

of the ?uid will ?ow through bores 20 in head 16 to form a seal between the abutting faces of bolt sections 15 and 16 and between the periphery of heads 17 and 19 and counterbore 10 to obturate the bolt bores thus providing a positive “lock-up” for a predetermined amount of hy draulic ?uid pressure against heads 17 and 19.

This “lock-up” is possible due to the “step” or reduc tion in wall dimensions due to counterbore 10 into which heads 17 and 19 ?t.

It will be} obvious that unless the hydraulic pressure of ?uid in chamber 9 is relieved, bolt heads 17 and 19 cannot move rearwardly and into chamber 9, or unless bores 18 and 20 are aligned to permit ?uid therethrough.

In ?ring position, the heads 17 and 19 are seated in counterbore 10, and bores 18 and 20 are not aligned. Rearward thrust on the forward face of forward bolt

15 caused by ?ring of a round in ?ring chamber causes

3,336,838 3

some of the hydraulic ?uid in chamber 9 to be forced through port 28 and against piston 30 which is biased forwardly by the spring 31 which has a preset load value. No ?uid can be forced into this area against the spring load pressure applied to piston 30 until the ?uid pres sure exceeds in p.s.i. the pressure preset against spring 31 and piston 30 by adjusting plug 29.

Plug 32 provides a buffer for bolt 16 when the weapon is ?red. As the bolt section 15 retracts, the empty cartridge

shell of round 14 in ?ring chamber 6 is‘ removed by the ejecting mechanism, not shown, and is ejected through the ejection slot 25.

Piston 30 returns to its forward position in bore 27 when the ?uid enters counterbore 10, since the pressure has been relieved in chamber 9. Spring 23 returns the bolt sections forward to its ?ring position and also the bolt section 15 strips another round 14 from magazine clip 13 and rams it into ?ring chamber 6.

After ?ring of the ?rst round, the ?ring of the other rounds will be automatic for as long as the trigger (not shown) is pulled. When the pistol 1 is exhausted of ammunition it will

be necessary to move the bolt sections to retracted posi tion by hand to reload.

Handle 24 is rotated in a counterclockwise manner to align bores 18 with bores 20 in heads 17 and 19 to per mit the heads to ‘be moved easily through the hydraulic ?uid since as the bolt sections 15 and 16 are retracted by handle 24, the ?uid ?ows through bores 18 and 20 in heads 17 and 19 to the forward side of the heads.

Bolt spring 23 forces bolt sections 15 and 16 closed for ?ring the initial round.

Hence, it is obvious that the bolt sections 15 and 16 are held in locked position by the hydraulic ?uid while ?ring the round 14 in ?ring chamber 6 and are obturated fully thereby.

While only a preferred form of the invention has been shown and described, other forms of the invention are contemplated and numerous changes and modi?cations may be made therein without departing from the spirit of the invention as set forth in the appended claims. What is claimed is: 1. A machine pistol comprising in combination, a re

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4 ceiver body, a barrel having a ?ring chamber at its breech end and being attached to said receiver body, there being an axial bore through said receiver body and in axial alignment with said barrel, said axial bore being counter bored to de?ne a chamber and a counterbore having a smaller diameter than said chamber, said chamber adapt ed to be ?lled with a hydraulic ?uid, means housed in said receiver ‘body for relieving the ?uid pressure in said chamber, a spring loaded forward bolt section slidable in said axial bore in said receiver body, a rearward bolt section slidable in said axial bore, an enlarged head in tegral with each bolt section and arranged in abutting relation, there being a series of circumferential, longi tudinally arranged bores through each head and the bores in the forward head being in offset relation with the bores in the rearward head during automatic oper ation of said pistol, both of said heads being slidable in said counterbore, said bolt sections being obturated and locked by the hydraulic ?uid when in ?ring position, the ?uid pressure in said chamber being automatically re lieved by said means upon recoil of said bolt sections whereby they are permitted to be fully recoiled, and means attached to said forward bolt section for rotating said forward bolt section to align said bores in said heads whereby said bolt sections may be retracted manually.

2. A machine pistol as set forth in claim 1 wherein said means for retracting said- bolt sections manually comprises a handle detaehably secured to the forward bolt section and extending through the ejection slot of said pistol.

References Cited UNITED STATES PATENTS

2,497,350 2/1950l Ferda ____________ __ 89-198 2,632,391 3/1953 Kintzinger ______ __ 89—194 X

FOREIGN PATENTS 339,486 6/ 1921 Germany.

BENJAMIN A. BORCHELT, Primary-Examiner. SAMUEL FEINBERG, Examiner. S. C. BENTLEY, Assistant Examiner.

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