US2382404A

US2382404A - Artificial hand and means for actuating the same

Info

Publication number: US2382404A
Application number: US468950A
Authority: US
Inventors: Frank V Eberle
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-12-14
Filing date: 1942-12-14
Publication date: 1945-08-14
Anticipated expiration: 1962-08-14

Description

ARTIFICIAL HAND AND MEANS FOR ACTUATING THE SAME Filed Dec. 14, 1942 3 Sheets-Sheet l IINVENTOR. FRANK 1 EBA-R45 Aug. 14*, LE ARTIFICIAL HAND AND MEANS FOR ACTUATING THE SAME 3 Sheets-Sheet 2 Filed Dec. 14, 1942 if 58 65a 1 65 56 I 6/ i G 4 o I I [3 625 l 24/ 4T TOE/VEV g 1945' F. v. EBERLE ARTIFICIAL HAND AND MEANS FOR AGTUA-TING THE SAME Filed Dec. 14, 1942 3 Sheets-Sheet 5 INVENTOR. FRANK 1 EBEELE BY Mia 27% Patented Aug. 14, 1945 OFFICE ARTIFICIAL HAND AND MEANS FOR ACTUATING THE SAME Frank V. Eberle, Newark, N. J.

Application December 14, 1942, Serial No. 468,950

6 Claims.

This invention relates to artificial limbs and more particularly to an improved artificial hand and means for actuating the same. This application is a continuation-in-part of my co-pendlng patent application, Serial No. 443,889, filed May Another object is to provide a novel and i proved means controlled by the movement of the remaining limb stump for actuating the artificial hand.

Other objects and advantages inherent in the invention will become apparent from the following specification taken in conjunction with the accompanying drawings which disclose by way of example an embodiment of the invention together with possible modifications.

Artificial appliances have heretofore been used to replace the missing member. However, because of the unsatisfactory experiences with the ordinary mechanical limb, attention has been directed toward the development of a substitute limb in which the control can be achieved by the movements of the remaining limb stump. In order to accomplish the intended purpose, it is imperative that the artificial limb be highly sensitive and immediately responsive to even minor impulses produced by the limb stump.

It is,. therefore, the particular purpose of the present invention to provide an artificial limb in which prosthesis can be activated by impulses provided by the limb stump.

In the drawings:

Figure 1 is a cross-sectional view of an artificial hand according to the invention with the adjacent portions of the wrist and the actuating lever mechanism;

, Figure 2 is a top plan view with the top plate removed:

Figure 3 is a detailed view of the locking mechanism;

Figure 4 is a plan view of the mechanism transmitting impulses of the arm stum to the lever mechanism of the artificial hand;

Figure 5 is a side view of Fig. 4 with a portion broken away;

Figure 6 is a side view of a modification together with a portion of the stump in which the prosthesis is activated by the mechanical movement of the stump;

Figure 7 is a side view of another modification together with a portion of the stump for mechanical activation of the prosthesis;

Referring in detailto the drawings, a frame or casing Ill represents the palm and the back of the hand. The front portion of casing I0 is provided with an opening I I in which the knuckle portions of fingers l2 are pivoted on a shaft l3.

The thumb I4 is similarly pivoted to a shaft l8 and extending through an opening l5 of casing l0.

An arched actuating lever ll extends from the knuckle portion of the fingers l2 into the casing I ii. A corresponding arched lever l8 extends from the thumb M in opposite relationship to a lever l1. Levers IT and I8 are so disposed that their ends move in substantially parallel planes toward and away from one another.

A crank I9 is keyed to the shaft 20 which is rotatably mounted in a boss 2|, which latter is preferably cast integrally with casing Ill.

An arched link 22 connects lever l1 to the crank 19. A second straight link 23 connects the lever I8 to crank l9. The pivot point of the link 23 is spaced from the pivot point of link 22 on crank it for the purpose of providing the relative movement between fingers I2 and thumb I t.

Crank I9 is actuated by a linear movement of a rod 2 lwhich is pivoted to a pin which, in turn, is anchored to crank i9.

To shaft 20 is also keyed a toothed segment 28 so as to move jointly with crank it. A pawl 21 cooperates with toothed segment 28 and is pivoted at 28 to a lever 29 which, in turn, is journaled at 20 to boss 2 l.'

Lever 29 has an arm 3|, the end of which is connected to the inside of the casing ill by means of a heavy spring 32. A light spring 88 connects pawl 21 with a second arm 34 of lever 29. By virtue of this construction, the pawl will become disengaged from the toothed segment 26 immediately upon release of the'locking mechanism,

which will be hereinafter described, and jump back to its normal position. The arm it limits the return movement of the lever 29 by striking the underlying surface of the casing Hi; this position is shown in Figure 3.

The locking mechanism comprises a plate 35 which is pivoted at 36 to a boss 37. The plate is rotatedby a lever 38 which projects into the palm through the opening 39 in casing Ill. A link an is pivoted at one end to plate 35 and at the other end to pawl 21 eccentrically of pivot point 28 of pawl 21.

When lever 38 is pushed forward in the direction of the arrow in Figure 3, it first brings the pawl into engagement with the toothed segment 28 against the strength of spring 38 and without rotation of segment 28. Further movement of the lever 38 will rotate the segment 28 together with the crank l8 and thus bring the fingers i2 and the thumb i4 tight together. The various levers and pivot points are arranged so that spring 82 will lock lever 88 in its forward looking position. By reason of this construction the force of the grip can be increased once contact has been made between the object and the fingers and the thumb and a tight grip of small objects is secured. It will also be understood that the fingers and thumb can be locked in any position intermediate the fully opened and fully closed position.

The casing i8 is providedwith a wrist collar 4| which may be rotatable with respect to the casing so as to provide pronation and supination of the hand. To the wrist collar 4! is attached a cuflf 88 by any suitable means.

As shown in Figures 4 and 5, the prosthesis is activated by the movement of the limb stump. The limb stump is supported in a cup 58 which is pivoted at 88 to braces 81 fastened to a support 88. This support is secured to the limb stump by any suitable means. Braces 81 are pivoted to brace 88 at 8i to form an elbow joint. Braces 88, in turn, are fastened to the cuif 88. The casing I8 is rotatably mounted in the cuff 88, as illustrated in Figure 1. Rod 24 is connected to one arm of a lever 82 by means of a link 83, but is rotatable in relation to said link. This is attained by providing the end of rod 24 with a flange which is rotatable in a suitable recess provided in the member 88. The other arm of lever 82 is pivoted to a shackle 84 which at the other end is connected to braces 81 by a pivot 88a. Shackle 84 is bent at 88 so as to cause longitudinal movement of the shackle 84 and a pivotal movement of lever 82 when the stump and the cup 88 are moved. The lever 82 is pivotally supported at 82a upon a support 82b connected to the cuif 88.

An artificial limb according to my invention is operated as follows:

If the artificial hand is to be opened or closed, the person using the hand moves cup 88, for example, by bending his limb stump. Any movement oi cup 88 causes an upward or downward movement of shackle 84 which, in turn, will rock lever 82. Assuming that the right arm of lever 82 is moved downward, rod 24 will be pushed into the hand. This movement of rod 24 will cause crank l8 to pivot about its axle 28. The pivotal movement of crank i9 is transferred to fingers l2 b links 22 and I 1 and to thumb it by links 23 and Hi. It is obvious from Figs. 4 and the original movements of cup 88 will be transmitted to the artificial hand at an increased ratio so that even slight movements of the limb stump will be sufiicient to actuate the hand.

As previously explained, a movement of rod 24 into the hand will result in an opening of the hand. Conversely a retraction of the rod 24 from the hand by an opposite movement of cup 88 will cause a closing of the hand. The locking device permits a locking of the fingers and the thumb in any desired intermediate position. It also secures a tight grip on any small object. If a hard object is-to be gripped between the fingers the user of the hand first closes his fingers as tight as he is able to do by a movement of the limb stump or with his good hand. Then lever 88 of the locking device, located in the palm of the hand, is slowly pushed upwards. Light spring 38 will close the fingers partly but not too tight.

The final tightening is made by heavy spring 82. In other words, if a hard object is to be gripped, the light spring will yield to a certain extent and permit a closure of the above-described locking device without any strain on any part of the lock, yet the hard object will be securely gripped betweenthe fingers.

In the modification shown in Figure 8, the prosthesis is activated by movement of the stump supported in a cup 88. A two-arm lever 81 which is pivoted to a brace 88 is rocked by the movement of cup 88 by means of a leverage mechanism including links 88 and 18 which are pivoted to a cross-bar II. The brace 88 is connected at 88a to the cup 88. One end of cross-bar H is connected to one arm of lever 81 by means of a link T2. The other end of cross-bar H is pivoted to a bell crank 13 which, in turn, is pivoted to the other arm of lever 81. A second leverage mechanism includes the following parts. Bell crank I8 is connected by means of a link 16 to one arm of another bell crank 15 which is pivoted at 18 to a brace 11. The other-arm of bell crank 18 is pivoted to rod 24. The joint between braces 88 and 11 corresponds to the elbow joint in the arm which is activated by separate means not forming part of the instant invention.

As it is apparent from Fig. 6, movements of cup 88 will result in a rocking of lever 81. The rocking motion of lever 81 is transmitted by bellcrank 13, link I4 and bell-crank '|8 to rod 24. Due to the arrangement of the various links and bell-cranks, the original impulse produced by a movement of cup 88 will be conveyed to the hand at an increased ratio.

A movement of cup 88 in one direction will causea movement of rod 24 resulting in an opening of the hand as previously explained, and a movement of cup 88 in the opposite direction will result in a retraction of rod 24 from the handle and hence in a closing of the hand.

Figure 7 shows another modification wherein the prosthesis is activated by the mechanical movement of the stump. A lever 18 is pivoted to a brace 18. One arm of lever 18 is connected through a link 88 to a bracket 8| which is fixed to a cup 82. The other arm of lever 18 is connected through a link 83 to a bell crank 84. Bell crank 84 is. in turn, pivoted to a bracket 88 which is anchored to brace 19. The other arm of bell crank 84 is connected to actuating rod 25.

A movement of cup 82 will be transmitted, by link 88 to lever 18 and cause a rocking movement of this lever. The movements of lever 18 will be conveyed by link 83 to the rod 24 and cause an opening or closing oi the hand as previously explained. It will be noted that the arrangement of the various levers and links results in a transmission of the cup movements at an increased ratio. The wrist collar 4| shown in Figure 1 may be conveniently employed in connection with the devices shown in Figures 6 and '7.

It will be understood that the invention has been described by way of example and not by way of limitation. The invention lends itself to a variety of expressions within the scope of the appended claims.

What is claimed is 1. An artificial limb comprising an artificial hand including a frame, a series of fingers and a thumb pivoted to said frame, a pair of arcuate levers connected to said fingers and thumb to open and close the hand, said levers being disposed in opposing relationship with their free ends movable in substantially parallel arcs, a

crank, a longitudinally movable rod for actuating said crank, a link connecting each of said levers with said crank, said links being so disposed as to transform the linear movement of said rod into' the pivotal movement or said fingers and thumb, a toothed rackmovable with said rod and connected to said crank, a pawl for engaging said rack, a leverage'mechanism connected to said pawl for moving said rack a predetermined distance, a two-armed lever pivoted to said pawl, a light spring between one arm of said lever and said pawl whereby said pawl will be disengaged from said rack immediately upon release oi said leverage mechanism, a second heavier spring between said lever and said frame for locking said pawl in a predetermined position oi said leverage mechanism and means controlled by the remaining stump for moving said rod.

2. An artificial limb comprising an artificial hand including a frame, a series of fingers and a thumb pivoted to said frame, a pair of arcuate' levers connected to said fingers and thumb to open and close the hand, said levers being disposed in opposing relationship with their free ends movable in substantially parallel arcs, a crank, a longitudinally movable rod for actuating said crank, a link connecting each of said levers with said crank, said links being so disposed as to transform the linear movement of said rod into the pivotal movement of said fingers and said thumb, a toothed rack movable with said rod and connected to said crank, a pawl for engaging said rack, a leverage mechanism connected to said pawl for moving said rack a predetermined distance, a two-armed lever pivoted to said pawl, a light spring between said lever and said pawl whereby said pawl will be disengaged from said rack immediately upon release of said leverage mechanism, a second heavier spring between said lever and said frame for locking said pawl in a predetermined position of said leverage mechanism, and means controlled by the remaining stump for moving said rod, said means including a leverage mechanism for actuation by said limb stump and a link mechanism for transmitting the movement of said latter leverage mechanism to said rod.

3. An artificial limb comprising an artificial hand including a frame, a series of fingers and a thumbpivoted to said frame, a pair of arcuate levers connected to said fingers and thumb to open and close the hand, said levers being disposed in opposing relationship with their free ends movable in'substantially parallel arcs, a crank, a longitudinally movable rod for actuating said crank, a link connecting each of said levers with said crank, said links being so disposed as to transformthe linear movement of said rod into the pivotal movement of said fingers and said thumb, a toothed rack movable with said rod and connected to said crank, a pawl rod, said means including a leverage mechanism for actuation by said limb stump and a link mechanism for transmitting the movement of said latter leverage mechanism to said rod at an increased ratio.

4. An artificial limb comprising an artificial hand including a frame, a series of fingers and a thumb pivoted to said frame, a pair of arcuate levers connected to said fingers and thumb to open and close the hand, said levers being disposed in opposing relationship with their free ends movable in substantially parallel arcs, a crank, a longitudinally movable rod for actuating said crank, a link connecting each of said levers with said crank, said links being so disposed as to transform the linear movement of said rod into the pivotal movement of said fingers and thumb and means controlled by the movements of remaining stump of the natural limb for moving said rod, said means including a cup secured to said limb stump, a leverage mechanism for actuation by movements of said sturnma two-arm lever actuated by said leverage mechanism, a second leverage mechanism actuated by said two-arm for engaging said rack, a leverage mechanism connected to said pawl for moving said rack a predetermined distance, a two-armed lever pivoted to said pawl, a light spring between said lever and said pawl whereby said pawl will be disengaged from said rack immediately upon release of said leverage mechanism, a second heavier spring between said lever and said frame for locking said pawl in a predetermined position of said leverage mechanism, and means controlled by the remaining stump for moving said lever for transmitting the movement of said twoarm lever to'said rod.

5. An artificial limb comprising an artificial hand including a frame, a series of fingers and a thumb pivoted to said frame, a pair of arcuate levers connected to said fingers and thumb to open and close the hand, said levers being disposed in opposing relationship with their free ends movable in substantially parallel arcs, a crank, a longitudinally movable rod for actuating said crank, a link connecting each of said levers with said crank, said links being so disposed as to transform the linear movement of said rod into the pivotal movement of said fingers and thumb and means controlled by the movements of the remaining stump of the natural limb'for moving said rod, said means including a cup secured to said limb stump, a pivotally supported two-arm lever, a leverage mechanism connectin said cup to one arm of said two-arm lever for transmitting movements of said cup to said arm and a second leverage mechanism connecting said rod to the second arm of said two-arm lever for transmitting movements of said two-arm lever to said rod.

6. An artificial limb comprising an artificial hand including a frame, a series of fingers and a thumb pivoted to said frame, a pair of arcuate levers connected to said fingers and thumb to open and close the hand, said levers being disposed in opposing relationship with their iree ends movable in substantially parallel arcs, a crank, a longitudinally movable rod for actuating said crank, a link connecting each of said levers with said crank, said links being so disposed as to transform the linear movement of 'said rod with the pivotal movement of said fingers and thumb and means controlled by the movements of the remaining stump of the natural limb for movin said rod, said means including a cup secured to said limo stump, a pivotaily supported two-arm lever, a bell-crank pivotaliy connected to one arm of said two-arm lever, a leverage mechanism connecting said cup with one arm of said bell-crank, a second pivotally supported bell-crank, a link connecting one arm of said first bell-crank to one arm of said second bell-crank and a pivotal connection between the other arm of said second bell-crank and. said rod.

FRANK V. EBERLE.