3 way finger joint

8/10/2019 3 Way Finger Joint

1/5

United S t a t e s Patent

[ 1 9 1

[ 1 1 ] 4 , 3 8 3 , 7 8 0

D a v i s o n [ 4 5 ] May 1 7 ,

1 9 8 3

[ 5 4 ]

THREE-WAY

FINGER JOINT

OTHER PUBLICATIONS

[ 7 6 ] I n v e n t o r : J o h n E . D a v i s o n , 2 3 6 6 C e d a r S t . ,

E r n e s t

J o y c e , E n c y c l o p e d i a o f F u r n i t u r e M a k i n g , S t e r

A p t .

2 ,

B e r k e l e y ,

C a l i f . 9 4 7 0 8 l i n g

P u b .

C o . ,

1 9 7 9 , p . 2 0 9 .

[ 2 1 ] A P P I -

N O - i 3 1 3 1 7 8 2

P r i m a r y

E x a m i n e r - A n d r e w V . K u n d r a t

_ A t t o r n e y ,

A g e n t , o r

FirmMichael

F .

Brown

[ 2 2 ] F 1 l e d : O c t . 2 1 ,

1 9 8 1

[ 5 1 ] I n t . C l . 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. .

F16B 12/00 [ 5 7 ] ABSTRACT

[ 2 g ]

h

4 0 3 / 2 1 9 ;

4 0 3 / 3 8 2 A t h r e e - w a y ? n g e r j o i n t f o r

j o i n i n g

t h r e e s t r u c t u r a l

[ 1 e o e a r c

/

4 1 g 2 1 7 3 8 2 3 6 4 e l e m e n t s c o m p r i s i n g a t l e a s t ?ve

l a y e r s

o f i n t e r l o c k i n g

3 / 3 3 9 3 4 7 4 0 0 ? n g e r s a n d s l o t s . The t o p a n d b o t t o m ? n g e r e l e m e n t s

o n

56 _ one member re i d e n t i c a l t o

each

other

a n d

t o the corre

[ 1 R e f e r e n c e s C t e d s p o n d i n g e l e m e n t s on t h e o t h e r m e m b e r s .

The

m i d d l e

U . S . PATENT

DOCUMENTS l a y e r s c o m p r i s e

a f u l l y i n t e r l o c k i n g

a r r a n g e m e n t

o f

3 6 6 , 8 6 5

7 / 1 9 8 7 N e w e l l

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 0 3 / 3 8 2

? n g e r s

39d

S I M S

i n

w h i f h

a l o n g

?nger

n

e a c h

member

7 2 5 4 2 2 4 / 1 9 0 3

Dorgan

4 0 3 / 3 8 2

mates

w1th c o r r e s p o n d i n g s l o t s on

t h e

o t h e r t w o . The

757:8]; 4/1904 Keyes _ _ _ _ _ 403/364 long ?nger

may

be

formed or

cut

off

to be ?ush i t h the

1 , 1 0 1 , 7 3 6

6 / 1 9 1 4 c r a in e 4 0 3 / 3 6 4 j o i n t s u r f a c e .

The

o i n t t h u s f o r m e d i s s t r o n g , r i g i d a n d

1 , 2 1 2 , 2 6 2

l / l 9 l 7

Rockwell

. . . . . . . . . . . . . . . . . . . . . . . . . . 403/364 a e s t h e t i c a l l y p l e a s i n g .

FOREIGN PATENT DOCUMENTS

102403

11/1937

Australia . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 403/364

180 0 4 76 6/1969 Germany . . . . . . . . . . . . . . . . . . . . .

4

C l a i m s ,

3

D r a w i n g F i g u r e s


2/5

US.

Patent May

1 7 , 1 9 8 3

S h e e t 1 0 1 2 4,383,780


3/5

US. P a t e n t M a y 1 7 , 1 9 8 3

S h e e t

2 0 1 - 2 4,383,780

F I G 3

I O / l i i n . n i i i


4/5

. .

THREE-WAY

FINGER JOINT

FIEL

OFTHEINVENTION

T h e

i n v e n t i o n

p e r t a i n s t o

j o i n t s h a v i n g

i n t e i ' i ? t t e d

m e m b e r s .

M o r e p a r t i c u l a r l y ,

t h e

i n v e n t i o n p e r t a i n s ' v t o

j o i n t s f o r

t h r e e

i n t e r c o n n e c t i n g

s t r u c t u r a l :

m e m b e r s

m e e t i n g i n a s i n g l e

p o i n t ,

i n

which

a l l t h r e e

members

have longitudinal

axe s

lying

in

a

single plane.

DESCRIPTION OFTHE RIOR ART

T h r e e - w a y j o i n t s a r e u s e d

t o

j o i n t h r e e s t r u c t u r a l

member, s u c h a s

t h e s t r e t c h e r s

u s e d

t o j o i n t h e l e g s o f a

t a b l e ,

c h a i r , o r s i m i l a r a r t i c l e o f f u r n i t u r e .

There a r e

two methods

m o s t o f t e n

u s e d

i n s u c h

a p p l i

c a t i o n s : b e n t l a m i n a t i o n s

and

s p l i n e s . The b e n t l a m i n a

t i o n

t e c h n i q u e c a l l s

f o r p r e s s i n g

t h i n l a y e r s o f

w o o d ,

c o a t e d w i t h

g l u e , i n t o

t h e d e s i r e d s h a p e w i t h f o r m i n g

b l o c k s ,

a n d h o l d i n g

u n t i l

t h e

g l u e

s e t s .

The l a m i n a t i o n

method c a n n o t , o b v i o u s l y , b e

u s e d

when j o i n i n g

s o l i d

p i e c e s o f w o o d .

The s p l i n e method

t i l i z e s

p e g s , o r s p l i n e s , g l u e d i n t o

s l o t s on

t h e

e n d s o f

t h e

members

t o b e j o i n e d . These

p e g s i n t r o d u c e an e l e m e n t o f

weakness

a t t h e j o i n t ,

and

r e q u i r e a d d i t i o n a l p i e c e s o f wood a n d

g l u i n g .

The

? n g e r - t y p e j o i n t

i s w e l l k no w n

i n t h e a r t

a s

a

m e t h o d o f j o i n i n g

two

e l e m e n t s s t r o n g l y a n d

r i g i d l y

( s e e ,

e . g .

K e y e s , U . S . P a t .

N o . 7 5 7 , 8 1 2 ,

o r D o r g a n , U . S .

P a t . N o . 7 2 5 , 4 2 2 ) . A n o t h e r e x a m p l e i s t h e w e l l - k n o w n

t r a d i t i o n a l b o x ,

o r

c o r n e r - l o c k , j o i n t f o r j o i n i n g

two

p i e c e s o f wood,

a s

i s commonly u s e d i n d r a w e r s and

t h e

l i k e .

I n h i s E n c y c l o p e d i a o f

F u r n i t u r e M a k i n g

( S t e r l i n g

P u b . C o . ,

1 9 7 9 ) ,

on

Page 2 0 9 ,

E r n e s t J o y c e shows s e v

e r a l t h r e e - w a y j o i n t s , i n c l u d i n g a

s p l i n e

a n d

two

? n g e r

t y p e

j o i n t s .

The

? n g e r

j o i n t s

d i f f e r

f r o m

t h e p r e s e n t

i n v e n t i o n

i n t h a t t h e ? n g e r s a r e n o t i d e n t i c a l among

t h e

t h r e e e l e m e n t s a n d

d o

n o t f u l l y

i n t e r l o c k , p r o d u c i n g

j o i n t s which a r e not a s

r i g i d ,

nor a s

b e a u t i f u l .

SUMMARY OF THE INVENTION

The

i n v e n t i o n i s a t h r e e - w a y j o i n t u s i n g p r o j e c t i n g

e l e m e n t s ,

formed a t

t h e

e n d s o f

t h e

members t o be

j o i n e d ,

a s

f u l l y - i n t e r l o c k i n g

? n g e r s

a n d m a t c h i n g

s l o t s

t o j o i n t h r e e s t r u c t u r a l members

i n a

w a y which s

a t

t h e

same

t i m e

s t r o n g , r i g i d ,

e a s y

t o a s s e m b l e , and b e a u t i f u l .

The

u s e o f

?nger

e l e m e n t s

which a r e i d e n t i c a l among

t h e t h r e e

members e n h a n c e s b o t h

t h e s t r e n g t h

and

t h e

e l e g a n c e

o f

t h e j o i n t , and e a s e s m a n u f a c t u r e and assem

b l y .

No

a d d i t i o n a l p i e c e s

b e y o n d

t h e

s t r u c t u r a l

membes

t h e m s e l v e s

a r e r e q u i r e d .

DESCRIPTION

OF THE

DRAWINGS

FIG. 1 shows

t h e j o i n t

i n e x p l o d e d v i e w .

FIG.

2 shows

t h e

j o i n t i n

? n i s h e d ,

a s s e m b l e d

f o r m .

FIG. 3 shows a t a b l e b u i l t u s i n g t h e j o i n t a s t a u g h t by

t h e i n v e n t i o n .

DESCRIPTION OF THE PREFERRED

EMBODIMENT

R e f e r r i n g

t o

FIGS.

1 a n d

2 ,

t h e

i n v e n t i o n c o m p r i s e s

a j o i n t f o r j o i n i n g t h r e e s t r u c t u r a l

members t o i d e n t i c a l

c r o s s - s e c t i o n ( A , B , a n d C ) h a v i n g l o n g i t u d i n l a x e s

l y i n g

i n

a

s i n g l e

p l a n e ,

a n d

r a d i a t i n g

o u t w a r d f r o m a

s i n g l e

p o i n t . The o i n t

u s e s a

p l u r a l i t y o f

e l e m e n t s

( ? n

g e r s a n d s l o t s ) t o j o i n

t h e

m e m b e r s , w i t h a

minimum

o f

?ve l a y e r s o f

? n g e r s

a n d s l o t s ,

a s

shown ( ? n g e r s 1 ,

3 ,

and 5 ; s l o t s 2 and ) .

The

r e f e r e n c e numbers a r e c o n s i s

4 , 3 8 3 , 7 8 0

710

20

2

t e n t

f r o m

member

t o member,

w i t h

t h e a p p e n d e d

l e t t e r

i n d i c a t i n g

t o

which member a n e l e m e n t b e l o n g s .

Thus

? n g e r ; 1 a , _ i s

t h e

t o p e l e m e n t o n m e m b e r , ~ . A , ? n g e r 1 b

t h e

i d e n t i c a l e l e m e n t on member

B , and s o

o n .

p Thetop ( 1 ) a n d

bottom

( 5 ) ? n g e r ' e l e m e n t s a r e i d e n t i

c a l

i n f o r m

t o

e a c h

o t h e r ( i . e . ( 1 a ) i s t h e

s a m e

a s

( 5 a ) )

a n d

i n

f o r m a n d t h i c k n e s s t o t h e c o r r e s p o n d i n g e l e m e n t

on t h e

o t h e r

members ( ( 1 a ) i s t h e same

a s ( 1 b ) and

1 0 ) ) .

W h e n a s s e m b l e d , t h e t o p ( 1 ) ? n g e r s

m e e t

a t a

p o i n t ( 1 4 )

w i t h o u t l e a v i n g g a p s , a s do t h e

b o t t o m ? n g e r s

( 5 ) .

I d e

a l l y , t h e

t o p

a n d b o t t o m ? n g e r e l e m e n t s a r e v f o r m e d i n

t h e ' s h a p e o f

a w e d g e , h a v i n g f a c e s m e e t i n g

a t

a n

a n g l e

o f 1 2 0

d e g r e e s a t

a p o i n t on

t h e

c e n t e r

a x i s

o f

t h e

mem

b e r .

The t h r e e wedge p o i n t s m e e t

a t

t h e s i n g l e p o i n t ,

w h i c h s

t h e c e n t e r

o f t h e

o i n t .

T h i s j o i n i n g r e p e a t s

t h e

p a t t e r n o f , t h e members

o f

t h e j o i n t

i t s e l f ,

l e n d i n g

a

p l e a s i n g a s p e c t

t o

t h e w h o l e .

The

m i d d l e t h r e e ( o r m o r e ) l a y e r s c o m p r i s e

t h e

i n t e r l o c k i n g o f l o n g ? n g e r s

m a t i n g w i t h

m a t c h i n g

s l o t s .

Looking a t t h e t o p m o s t

m i d d l e

l a y e r i n FIG.

1 , one

c a n

s e e t h a t

e a c h

l a y e r

c o m p r i s e s

a

l o n g

' ? n g e r

( 3 0 )

f r o m

one member

? t t i n g

i n t o s l o t s

on

t h e o t h e r t wo members

( ( 2 a ) , ( 4 b ) )

which

a r e

s o

formed a s

t o

mate with

t h e

? n g e r

w i t h o u t

a g a p . S i m i l a r l y , t h e n e x t l a y e r

i s made

up o f ( 3 a ) ? t t i n g i n t o ( 2 b ) and ( 4 c ) ; and t h e bottommost

3 0

3 5

4 5

5 5

m i d d l e l a y e r

s

( 3 b ) , ( 2 c ) a n d ( 4 a ) .

Each

t r u c t u r a l

mem

b e r

h a s a t

l e a s t o n e l o n g ? n g e r ( 3 ) a n d two

l o t s

( 2 ) a n d

( 4 ) . The minimum

number

o f

m i d d l e

l a y e r s

t h u s

s t h r e e ,

a s

shown, b u t i t

w i l l

be r e a d i l y a p p a r e n t t o

one

s k i l l e d i n

t h e a r t

t h a t

a d d i t i o n a l

l a y e r s may

be

added

i n a

s i m i l a r

f a s h i o n

t o t h e ? r s t t h r e e , i f

d e s i r e d . For

e x a m p l e , t h e

j o i n t

c o u l d

b e

made

up o f a l a r g e r number o f t h i n n e r

e l e m e n t s , i f

t h e

d e s i g n e r w i s h e d , w i t h o u t d e p a r t i n g

from

t h e t e a c h i n g s

of

t h e

i n v e n t i o n .

The

e n d

( 6 )

o f

t h e

l o n g ? n g e r e l e m e n t

( 3 )

f o r m s

p a r t

o f t h e

o u t s i d e s u r f a c e

o f t h e

j o i n t ,

a s shown

i n

FIG. 2 .

The ? n g e r may b e

f o r m e d i n i t i a l l y

w i t h

a n

e n d a d a p t e d

t o become

a

?ush p a r t o f t h e s u r f a c e , a s

i n

end

( 6 )

o f

? n g e r ( 3 a ) ,

o r ,

i f d e s i r e d ,

t h e

? n g e r may b e l e f t s q u a r e ,

a s i n e n d ( 7 )

o f . ? n g e r

( 3 b ) , a n d l a t e r

t r i m m e d

f l u s h ( 8 )

f o r

a n exact ?t a f t e r assembly. _

The e l e m e n t s

o f

t h e o i n t may

e

f a s t e n e d

t o g e t h e r

by

g l u i n g , o r by any

o t h e r

method known o t h e a r t , form

i n g

a s t r o n g , r i g i d , and a t t r a c t i v e j o i n t , a s may b e u s e d

i n

t h e c o n s t r u c t i o n o f ?ne f u r n i t u r e .

FIG.

3 shows a t a b l e d e s i g n e d by t h e i n v e n t o r which

u s e s t h e j o i n t a s

t a u g h t

by t h e i n v e n t i o n .

The t a b l e

h a s a t o p

( 9 ) , f r a m e ( 1 1 )

a n d

f o u r l e g s ( 1 0 ) .

The

l e g s

a r e

h e l d

by

a

s t r e t c h e r

made

up

o f

f o u r

l e g

s t r e t c h e r s ( 1 2 )

a t t a c h e d

t o

a

c e n t e r l o n g i t u d i n a l

s t r e t c h e r

( 1 3 ) . The s t r e t c h e r s m e e t

a t

( 1 5 )

a n d

( 1 6 )

i n

j o i n t s c o n s t r u c t e d a c c o r d i n g t o t h e

t e a c h i n g s

o f t h e

i n v e n t i o n .

A c c o r d i n g l y ,

i t

i s t o b e u n d e r s t o o d

t h a t t h e

embodi

ments o f t h e i n v e n t i o n

h e r e i n

d e s c r i b e d a r e merely

i l l u s t r a t i v e

o f t h e a p p l i c a t i o n o f t h e

p r i n c i p l e s

o f t h e

i n v e n t i o n .

R e f e r e n c e

h e r e i n

t o d e t a i l s o f

t h e

i l l u s t r a t e d

embodiment are

not

intended to

l i m i t the scope of

the

c l a i m s ,

w h i c h

t h e m s e l v e s r e c i t e

t h o s e

f e a t u r e s

r e g a r d e d

a s e s s e n t i a l

t o

t h e i n v e n t i o n .

I c l a i m :

1 . A o i n t

f o r

j o i n i n g t h r e e s t r u c t u r a l members o f

i d e n t i c a l

c r o s s - s e c t i o n

h a v i n g

l o n g i t u d i n a l

a x e s

l y i n g

i n

a s i n g l e

p l a n e a n d m e e t i n g a t

a s i n g l e

p o i n t , c o m p r i s i n g :

t h r e e

s t r u c t u r a l

members o f i d e n t i c a l c r o s s - s e c t i o n t o

b e j o i n e d , e a c h

h a v i n g

a n

a r r a n g e m e n t

o f ? n g e r

e l e m e n t s

formed a t one e n d , s u c h t h a t

t h e

?nger


5/5

4 , 3 8 3 , 7 8 0

3

e l e m e n t s i n t e r l o c k t o f o r m t h e j o i n t , j o i n i n g t h e

members

r i g i d l y

w i t h o u t g a p s ;

t h e ? n g e r e l e m e n t s f o r m i n g

t o p , b o t t o m ,

a n d a t

l e a s t

t h r e e m i d d l e l a y e r s ;

t h e t o p a n d b o t t o m

l a y e r s

c o m p r i s i n g

? n g e r e l e m e n t s

of a ?rst type which re i d e n t i c a l on l l three mem

b e r s ;

e a c h

m i d d l e

l a y e r c o m p r i s i n g

o n e

? n g e r e l e m e n t

o n

one member and t wo s l o t s

on

t h e t wo a d j o i n i n g

m e m b e r s ;

t h e ? n g e r e l e m e n t o f e a c h m i d d l e l a y e r b e i n g o f

a

s e c o n d t y p e , o f

s u f ? c i e n t

l e n g t h t o p r o t r u d e

f r o m

t h e s u r f a c e

o f

t h e j o i n t ;

t h e s l o t s o f

e a c h m i d d l e

l a y e r b e i n g a d a p t e d t o m a t e

w i t h t h e ? n g e r

e l e m e n t

o f t h e a d j o i n i n g

s t r u c t u r a l

member w i t h o u t g a p s ;

1 5

20

2 5

30

3 5

4 5

5 0

5 5

6 5

4

t h e ? n g e r

e l e m e n t s

a n d

s l o t s o f t h e m i d d l e l a y e r s

b e i n g a r r a n g e d s u c h t h a t e a c h

s t r u c t u r a l

member

h a s

a t l e a s t one ?nger e l e m e n t

o f

t h e s e c o n d

t y p e

m a t i n g w i t h

c o r r e s p o n d i n g s l o t s o n e a c h

a d j o i n i n g

member.

2 . The o i n t o f c l a i m

1

i n

which

t h e ? n g e r

e l e m e n t s

o f

t h e middle l a y e r s a r e trimmed

i n

l e n g t h a f t e r

a s s e m b l y

such

t h a t

t h e

end

o f each ?ng er e l e m e n t

o f

t h e

middle

l a y e r s i s ? u s h

w i t h

t h e s u r f a c e s o f

t h e

a d j o i n i n g s t r u c

t u r a l

m e m b e r s .

3 . The o i n t

o f

c l a i m 1 i n which t h e

e n d

o f

t h e

? n g e r

e l e m e n t s o f

t h e

m i d d l e

l a y e r

a r e

a d a p t e d t o

b e

?ush

w i t h t h e

s u r f a c e s

o f t h e a d j o i n i n g

s t r u c t u r a l

members

a f t e r a s s e m b l y o f

t h e j o i n t .

4 . The o i n t o f c l a i m

1

i n

which t h e ? n g e r

e l e m e n t s

o f

t h e

t o p and bottom

l a y e r s a r e

w e d g e - s h a p e d w i t h

t h e

f a c e s o f t h e

we d g e

m e e t i n g

a t

a n

a n g l e o f 1 2 0

d e g r e e s .

t * i i i

3 way finger joint

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