US1725588A - Artificial limb - Google Patents

Description

Aug. 20, 1929. J, H. KosEK ARTIFICIAL LIMB Filed Sept. 10, 1925 Patented Aug. 29, 1929.

UNITED STATES 1,725,588 PATENT OFFICE.

JOSEPH H KOSEK, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO DAVID W. DOB

RANGE, OF MINNEAPOLIS, MINNESOTA.

ARTIFICIAL LIMB.

Application filed. September 10, 1925.

My invention relates to improvements in artificial limbs and particularly to a hand appliance adapted to be attached to an armstump socket and operated through the usual pullcord anchored to one of the shoulders of a wearer.

An object of the invention is to provide a simple, durable and relatively inexpensive substitute for the human hand, the same including a pair of complementary fingers and means for opening and yieldingly closing said fingers, said means embodying a toggle mechanism through which a pullcord easily acts to open said fingers, but by virtue of which said fingers otherwise are powerfully held against opening.

Another object is to supply an article of the present nature in which finger tip members on oppositely bowed fingers form convenient hooks.

With the foregoing and other objects 1n view, which will appear in the following description, the invention resides in the novel combination and arrangement of parts and in the details of construction hereinafter described and claimed.

In the drawings, Fig. 1 is a perspective view of an article embodying my, invention, the same being illustrated as applied to an arm-stump socket, Fig. 2 is a plan View of said article, a portion of the shank head being broken away to show clearly those portions of the fingers and toggle mechanism that are otherwise concealed, and Fig. 3 is a detail view partly in plan and partly in sec tion, the same illustrating particularly the butt end of the shank and the plunger of the toggle mechanism.

Referring to the drawings, it will be seen that my improvement includes a shank A and fingers 10. The shank A is threaded exteriorally at the butt thereof, the tip being bifurcated to form a yoke-like head having opposed, spaced head members or plates a. The shank A, formed with an axial bore 11 therein opening between the head plates at, provides a socket for a plunger spring 12 and plunger 13 to be more fully hereinafter described. The fingers 10 are oppositely bowed and are pivoted at their butts to and between the ends of the head plates a by means of pintles 14, said fingers being formed with inter-meshing gear segments 15 formed thereon and struck from centers in' the axes of their respective pintles 14:. Ex-

Serial No. 55,485.

tending rearwardly and outwardly from the butt of each finger 10 is an arm 10 The previously mentioned plunger spring 12 is a helical expansion spring which is seated at one end thereof in the bore 11 in the shank A. One end of the plunger 13 is fitted within this spring, said plunger having an arm 13 thereon, the same abutting against the free end of the spring and extending outwardly from and between the head plates w. The head of the plunger 13 is kerfed as at 13 the ends of the arms 10 of the fingers 10 being also kerfed as at 10 and in the same plane as the kerf in the plunger 13. A pair of toggle links 16 are disposed at their inner ends in the kerf 13 of the plunger 13 and pivoted to said plunger by means of pintles 17. The outer end of one toggle link 16 is fitted in the kerf 10 of one arm 10? and pivoted to said arm by a pintle 18, the outer end of the other toggle link 16' being likewise fitted in the kerf 10 in the other arm 10 and pivoted to said arm.

The free end of each finger 10 merges into a flattened tip member 10 which extends bearing against a resilient washer 21 re-,

cessecl in said head of said socket. With the article thus attached to the socket 19, the pull cord 22 is connected with the actuating arm 13 on the plunger 13. In retracted position of the stump socket, wherein the cord 22 is loose, the spring 12 operates through the plunger 13 and toggle links 16 to yieldingly close the fingers 10 and clamp the tip members 10 together face-to-face (solid lines, Fig. 2). Under a forward thrust of the arm socket 19 and due to the pulling of the cord 22 on the arm 13 as a result of such thrust, the plunger 13 is retracted against the action of the spring 12. Thus retracted, the plunger 13 separates the fingers 10 through the medium of the toggle links 16, the movements of said fingers 10 being co-ordinated by reason of the intermeshing gear segments 15. With the tip members 10 of the fingers engaged one with the other (solid lines, Fig. 1), the toggle links 16 are almost on center, the result being that forces required in opening the fingers 10 by application to said fingers themselves must be much greater than the strength of the spring 12. And the same holds true in the various separated positions of the fingers 10. In taking the bail of a bucket or in catching any such small object through which weights or pulls are to be met in the artificial hand, it is convenient to catch the same in one of the hooks formed by one of the fingers 10 and its respective tip member 10. With an object caught in one of these hooks, none of theiesistance occasioned thereby has any tendency to spread the fingers 10, My device, therefore, is adaptedto uses that could not be served in the absence of a spring 12 so powerful as to negative ease of operation in carrying out other important uses.

Changes in the specific form of my invention, as herein disclosed, may be made with in the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Letters Patentisz' 1. In an article of the class described, a shank for attachment to an arm-stump socket, said shank having a bifurcated head and an axial bore opening into the space between the spaced head members, co-operating fingers fitted at the butts thereof between said head members and pivoted thereto, said fingers being geared together and each thereof formed with a rearwardly projecting arm, a coiled expansion spring seated within said bore in said shank, a plunger fitted within said spring, said plunger having an arm near the head thereot, said arm extending out- Ward between said head members and abutting against the head of said spring, and a pair 0t links, one for each finger, each link being pivoted at one end thereof to the arm of its respective finger and at its other end to the head of said plunger.

2. In an article of the class described, a shank for attachment to an arm-stump socket, co-operating fingers pivoted on said shank and geared, one to the other, a spring pressed plunger mounted on the shank, toggle links connecting said plunger with said fingers, and an arm on said plunger for retracting the same to open said fingers.

3. In an article of the class described, a shank for attachment to an arm-stump socket, a pair oi oppositely bowed complementary pivoted fingers carried on said shank, means to bring said fingers together at the tips thereof, each finger having a flattoned tip member, a portion of each member extending back into the space between said bowed fingers to form an inside hook, the remaining portion of each member extending toone side and co-operating one with the other to grip articles at the side of said fingers. V

4. In an article of the class described, a member for attachment to an arm stump socket, a second member movable relative to said first named member, a pair of complemental fingers pivoted to one of said members, and a pair 01": links each pivoted at on end to one of said fingers and at its other end to said other member, the pivots or said links being adapted to lie in substantial alignment in the closed position of said fingers.

, In testimony whereof, I have signed my name to this specification.

JOSEPH H. KOSEK.

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