US48659A - Improvement in artificial arms - Google Patents

Description

PATBNTED JULY 11, 1865.

J. OONDELL. ARTIFICIAL ARM.

' UNITED STATES PATENT ()FFICE.

JOHN GONDELL. or MORRISTOWN,'NEW roux.

IMPROVEMENT m ARTIFICIAL ARMS. I

Specification forming part of Letters Patent No: 48,659, dated July 11, 1865.

To all whorl "it may concerm.

Be it known that I, J omv CONDELL, of Morristown, in the county of .St. Lawrence and State of New York, have made certain new and useful Improvements in Artificial Arms; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying draw-, ings, which are made part of this specification, and in which' Figure 1 represents the arm with the ap My arm is adapted to be "used. incases of amputation of the upper arm-that'is to say, where the operation is performed between the shoulder and elbow, and it isin-tended to give the wearer the command of the elbow-joint by flexion and extension, and also to command themotion of the hand, these operations being'performed independently of the assistance of the opposite armor exterior objects.

Myimprovementsconsist,first,intheappendage by which the arm. is supported without interference with the. action of .the thorax, and

which afi'ords practically rigid points, in connection with'which the vibration or rotation on combined motions of the stump are caused to produce the requisite motions of the elbow.

and hand; second, in the method of producing the flexor and extensor motions of the forearm; third, in the combination of springs and levers by which the said fiexor and extensor motions are induced, modified, and controlled; fourth, in the construction of the elbow-joint; fifth, in. the radial or rotary movement of the lower end of the forearm; sixth, in the method of producing the motions of the metacarpns; seventh, in the'plia-langeal articulations and action.

To enable others skilled in the artto which my invention appertainsto fully understand and use the same, I will proceed to describe its construction and operation.

A is the socket or upper portionof the arm,

being attached to the other portion or frame A, to which the lower arm is pivoted.

The supporting appendage or band, Fig. 4, by which the artificial arm is supported, consists of two belts, B B, of webbing'o'r other suitable material, which are united at the end and terminate in a strap, 0, which is under the axilla of the natural arm of the patient; thencepassinginfrontof and behind the shoulder respectively, they cross on the back at O, and by their continuations D D and buckles D D, which latter are on the front and rear of theishoulder, are attached to the straps E and Gr, respectively, by which the arm is suspended. I

The forearm is pivoted to the upper arm by a bolt, Q, which passes through the frame A of the latter and through two side bars ormetallic connections, T, which are riveted to the former. The bolt is rigidly secured to the bars T, so that it rotates with the flexing and extension of the elbow-joint and upon it is'a radial arm, P, the purpose of which will be prc sently described.

,K is a pillar which extends across inside the frame A of the arm and is secured by a bolt,-K', which is parallel to the hollow boltQ, which forms the axis of articulation of the elbow. Upon this pillar K and vibrating at' right angles to the axis of the same-is aframe, L, which is connected at the points F H, with the flexor and extensor straps'E G, which, as

has been said, are connected to the back-straps at D D. a l

Screwed or riveted to the frame U of the lower arm is a plate, W, to which an arcshaped connecting,-rod,R, is pivoted at S, and the rod R is at its other-end pivoted at O to the apex of the triangular frame L. By the motions of this frame communicated through the rod R to the forearm, the fiexion and'extension of the latter is directly efl'ected, I wish to remark here, however, that in addition to the forces which act directly upon theframe L- namely, the straps E and G and the springs E and N-the motion of the stump will have the effect of communicating an impetus to the forearm in the direction in which it is moved, and also that when the arm is placed in certain positions its gravitation will cause it to vibrate upon the elbow-joint in either direction, according as the axial point Q is inclined in one direction or the other. The fiexorspring I is attached at 70 to the socket A, and by a link and strap, J, to the end F of the frame L. The extensor-springN is attached at M to a hook on the frame L, and at its other end to the arm P, which projects radially from the axial elbow-boltQ. These springs are proportiened totheir respective duties, but the main agent in producing the flexion and extension of the forearm are the straps E G, which being secured at D D to points which are practically rigid, are caused by the forward and backward motions of the stamp to become tightened or slackened. The forward motion of the stump tightens the strap E, rocking the frame L, and causing the point S to move inwardly in the direction of the arrow, the motion being assisted by the contractile power of thesprin'g I, and being in opposition to the spring N which is elongated by the rotation of the arm P around the elbow articulation, which describes a longer are than the com paratively slow moving point M. The extension of the arm is directly due, independent of' mere impetus derived from an outward motion of the arm to the tightening of the strap Gas the stump is moved backwardly, and this motion is assisted by the contractile power of the spring N exerted on the arm Pof the axial bolt Q, and it is in opposition to the power of the spring I.

The object of the arrangement ofthe definitive and elastic forces is to bringa nicely-a djusted and certain but gently-acting pressure to bear in the required direction, so that the motion may be attained without jerking or unnatural movement, but smoothly and noiselessly, in imitation of the livingvmcmber.

Themetacarpus is hinged to the wrist by means of the plates j, one on each side, which are pivoted to the plate which embraces the back ofthe Wrist. Upon this pivoted point the metacarpus rocks forward under'the impulse of a cord, e, connected by a vibrating l'ever, d, which rocks upon a' plate, g, under the tension of a cord, 0, and strap a, the latter connected to the crossing-place O of the bands B D B D. The required tension upon the said series of strap and cords to pro'duce the forward motion oft he metacarpusis effected by a forward and rotary movement of the stump which, strains the strap a, rigidly attached at C over the point of the shoulder.

This motion is in opposition to the spring Z and its tendons Y f, which connecta pillar, X, in the frame U of the forearm with the metacarpus, back of or above its center of vibration, so as to cause it to incline backward when at rest. Thus the forward motion. of the metacarpns, which, as will be presently shown, opens the hand, is effected by a definite pull upon the cords, while the backward motion of the metaearpns, closing the hand, is effected. by the eonstant spring Z and its tendons, and is constituted the normal position of the hand.

The rotary motion in imitation of the relative movement of the radius and ulna on each other, of the forearm is effected by means of It is now in order to describe the motions of the fingers, anda description'of one will substantially apply to each of the others, as they only dift'erin the matter of proportion. This difference arises from two circumstances: One istheir difference in point otlength, and the other that in following the natural motion of the phalanges it becomes necessary to increase in speed from the fore to the little finger, as the metacarpus.- Upon this point the, frame,m.vi-

brates as the-hand opens and closes. The point 2 on the frame is connected by a rod, '19, with the wrist-plate I, where it is'pivo'ted in common with the similar rods 1) p from the other fingers. 'To point-3on the said; frame is pivoted a second frame, g, which is pivoted at 5 to the terminal section, r, of the finger.

Beyond the metacarpus the phalang'eal frame may be'said to be the pieces on and q,- but for thepurpose of smying these and connnunicatin g motion to them fourrods are used, besides the rod p,which passes up the back of the hand from the wristplate to the point 2, which rep resents the first .knnckle at the connection of the phalange with the metacarpus. The first of these rods is-s,-which connects the points 2 and 3 fromthe knuckle to the firstjoint of the finger. The principal use ot'this is to strengthen, as the definitive motion of the frame in does not depend upon it, though it becomes nearly in line with p when the hand is expanded,and forms a good outer surface to keep the buckskin covering of the hand from getting among the levers. The second of these rods, t, is riveted to the metacarpus, and is a fixed point relativcl y to that, but pal-takes of its vibratory movements when the latter is acted upon by the cords f e, respectively, to close and to open the hand. One end of the rod to is pivoted to the end of rod 25 at g, and the other end is pivoted to the point 7 on the piece q, its elfect being, as the hand closes, to draw the said point inward, vibrating the piece q upon the'point 3 of the frame 112. One other rod remains to be described, and that is marked w. it extends from the point 4 of the frame at to the point 8, which is at the upper part of the terminal section of the finger. i

The open and the closed positions of the fingers are shown in the respective section S,.Figs.

tion. To preserve a .graceful motion of the fingers which is pivoted to it at 8 and to the frame in The closing of the hand is caused,'as has been said-,by theconstant spring Z and its tendons,

- and the actions on the metacarpus and fingers is substantially the reverse of the opening mothe rate of their motionincreases from the forefinger to the little finger, so that when closed the little finger shall be most bent and the others proportionably. This is accomplished by modifying the length of the moving parts.

. Some of the, plates and rods, such-as the plate q and the rods 8, u, and w, are duplicated, as

. will be seen more especially in the upper view of the band, Fig. 3. This is to insure steadiness and strength. I may duplicate other parts than those mentioned, or may make changes in these. In speaking of these rods, I have .mentioned them in the singular number for brevity and for clearness, as too rigid persp1 two definite pivoted points, 1011, at ,the .base

of the thumb, and they are connected, by the frame in and the rod 9 with the pivoted points 12 13 on the base of theierminal section of the thumba. The frame a: is prolonged at an angle, where it connects by a rod, z, ;with the wrist-plate L, which is attached to the forearm. The rod b acts as a stay, and also maintains the proper contour of the part. The opena ing of the thumb is efiected by the forward -motion of the metaearpus,-which pulls upon the rod 2, which withdraws. the short arm of the frame a, rocking "the said frame on its pivoted point 11, drawing back the second phalange of the thumb, while the rod 3 rocks backwardlyand rotates the terminal section of the thumb outwardly.

In'cases of disarticulation at the elbow it 4 becomes necessary to abandon the whole inte'rior of the socket to the use of the stump,

and, as anartificial elbow-joint is still required,

the arrangement of rocking plates andconnec- .jtions must be located outside. Presuming that a short addition to the length of the humerus might not be objectionable, the axial-bolt may still be placed in the endof the socket, close to the end of the stump, and the arm P on the bolt maybe reached by an orifice in the socket.

I do not think it necessary to define the exact modification that would be rendered desirable under possible circumstances, but shall rest my claims to a set of devices irrespective of exterior or interior location.

Having thus described my invention, what I claim therein as new, and desire to secure by Letters Patent, is-

11. The appendage, Fig. 4, which is adapted to maintain its place by means of its axiliary attachment, so as to afiord two definite and practically rigid points, D D", to which the flexor and extensor straps or cords are to be attached, so as to produce those motions by the forward and backward movements of the stump. I

'2. The cord a c e, or its equivalent, with or without the intervening lever (1, and attached substantially as described, by which the forward motion ofthe metacarpns is obtained.

-3. Attaching the flexor and extensor cords or straps to points on the front and rear of the shoulder-joint, so as to be brought into action by the forward and rearward motions of the. stump.

- 4. The combination of the flexor and extensor straps with the rocking frame L or its equivalent, which connects by link or otherwise with the forearm. v

5. The flexor-spring I,'attached to the socket and tothe rocking frame L, or its equivalent.

6. The combination of the springN with the arm P, on the axial bolt, and the rocking frame L. I g

7. The spring Z, with its tendons Y F, or their equivalent, and extending from apoint in the forearm to a point back of the center of vibration of the metacarpus, substantially as described.

8. Artie'ulatin g the metacarpus tothe end of,

' motion. however induced, of the metacarpus.

11. .Pivoting the frame-piece m of the fingers to a point on the 'metacarpus, and the rods, which, under, the motion of the metacarpus, primarily induce the deflection of the fingers to a point ,on the forearm.

, l2. Pivoting the second joint of the framepan 9 to a point of the frame-piece m, and the rod which gives the additional deflection due to the second joint to a point attached to or con nected with the metacarpus.

13. Giving the additional deflection due to the terminal section or first joint of each finger by a rod attached toitand to a point on the frame-piece m. r

14. Governingthe motion of the thumb by a rod attached to the endoftheforearm, which, under the vibration of the metacarpus, infinences the frame-piece a: and gives the deflection due to the second joint of the thumb.

15. Givingthe deflection due to the first joint of the thumb by means of the rod 3 which performs thatoflice as the frame-piece w is vibrated by the rod Z when the metacarpus is moved.

Witnesses: V JOHN OONDELL.

EDWARD H. KNIGHT, CHARLES D. SMITH.

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