US1458923A - Artificial arm - Google Patents

Description

June 19, 1923. 1,458,923

D. M. ANDERSON ARTIFICIAL ARM Filed June 5, 1922 wrn.

Patented June 19, 1923.

DUNCAN, MACKENZIE ANnERs0N',..or MAIN'Z, GERMANY.

ARTIFICIAL ARM...

' Application filed June 3,

To all whom it may concern:

Bevit known that. I, DUNCAN MACKENZIE ANDERSON, a citizen of Canada, residing'at' Mainz, Germany, have invented certain new and useful Improvements in Artificial Arms, ofwhich the following is a specification.

To produce the movement of the forearm of an artificial arm attached to a stump of the upper arm by traction means connected with the forearm and with a fixed point of the human body and conducted over inter-.

posed reversin elements, has become known already. The ending position of the upper arm is produced. with devices of thistype by the stump.

This invention relates to an improvement of artificialarms of this type in such a sense, that thetransformation of the lifting movement of the shoulder into the lifting move-- ment of the artificial arm is effected, with exclusion of elements. situated outside the artificial arm except thepoints of attach-' ment to the human body, from points which are-all situated in the artificial arm, and enclosed and hidden by the same,- the ele ments for changing the direction of I the traction element being supported in *the shoulder joint of the artificialarm, whereby further the angular torsion of the guiding elements in the shoulder joint, which occurs at the lifting of the shoulder, is transferred at first only upon the joint of the forearm to produce the bent position of the forearm to be transferredonly hereafter for producing the lifting of the whole ar'm.. Owing to the suppression of reversing elements for the pull rope arranged outside the artificial arm, the attachment and the carrying of the artificial arm is facilitated and rendered morecomfortable, its use. is

less exposed to disturbances and the elements for transmitting and executing the movements are well protected inthe artificial arm. The increase. of weight is of little importance as the principal mass of the reversing elements is situated in the shoulder joint and has to be drawn along only very little at the lifting of the arm.

An embodiment of the invention is shown on the accompanying drawing, wherein 5-- Fig. 1 is a diagram illustrating the idea of the invention.

Fig. 2 isa front elevation, the artificial arm being shown cut open.

Fig. 3 is a side elevation viewed from the left, the artificial arm being omitted.

1922. Serial No. 565,760.

If to the human body and upon'the cor- I respondingshoulder, with the aid of a bandage 1, an artificialv armis'attach'ed"whose upper arm 2 is articulated to the bandage by a pivot pin'and whose forearm is articulated in the well known manner to the up-- per'arm, andif' further from a fixed point 4: of the human body a pull rope 5 isguided over; a pulley 6 pivotally mounted in'the shoulder joint where theend of saidrope is made fast after having been wound partly or completely around said pulley, in. y order that the rope with the pulley can 6X8 cutean angular rotation, and. if a second pulley 7 rigidly coupled with the first mentioned pulley is connected in the same manner but in inverse succession by a pull rope 8 with the artificial;forearm, the pulleys 6 and .7 can executean'angular rotation if the shoulder .with the artificial arm is lifted, OWlIlgtO the lengthening of the distance between theffixed point a and the joint of the shoulder, the artificial forearm and later, on thewhole arm being thus able to execute a bending movement ill-the direction of the arrow. At the loweringof the shoulderthe initial position is resumed by the action of the natural weight or with the aid of springs.

This is'the principle upon'which' the form of. construction shown in Figures 2 and 3 is-based'. Y

The artificial armis attached to the body in the Well known manner by straps which terminate at the shoulder joint in a leather sleeve or having a metal bow b withthe trav erse 0 serving as'bearing. This travel-sec forms together with thefrontend of the journald; theQsho-ulder oint. Upon the rear part of the journal (Z the: pulleys e, f for changing the direction of the ropes are 1 mounted which are rigidly connected the one with the other. Uponthefront parti of the journal 03' a joint cross is mounted which embracesa connecting rod h from: both sides. The artificial upper arm z is connected with the front ends of the cross 9 (Fig.

2). The artificial upper arm 11 is open at the upper end and covered by a leather cap is (Fig. 3). Parallel rods Zhinged tothe cross 9 are mounted at their lower ends each by an eye upon the pivotpin n. The jointcross 9 has further two parallel arms 9" which are bent at a convenient angle and have each an angularly bent slot 0. Be-

tween the arms 9 an arm 72, of the con-,

necting rod 71. is located which has laterally projecting studs p engaging with. the slots 0. The connecting rod it has a vertical longitudinal slot Q traversed by the journal cl and by an upper stud 7" supported by the traverse c. The connecting rod h is hinged by an articulation t to a rod 14 which has a longitudinal slot 1) guided upon the bolt 72. To this bolt n the artificial forearm i is attached by means of lug-straps 'w, the forearm being. united with the artificial upper arm by a ball joint the pivot pin of which is formed by bolt n. Upon'the bolt n inclined arms :0 arranged in pairs are fixed which have longitudinal slots at and enclose a lug; u. of the rod a, which engages by a bolt y withthe longitudinal slots 00. Upon the bolt 1 a rod 2 is further mounted by its lug, said rod being extended by a chain 2 guided uponthe pulley f and fixed to the crown of the same. The pull rope j attached with one end at a convenient point of the: body is guided over the pulley e and attached with its other end in the groove of the pulleyafter it has been wound around part of the pulley. 1

If the shoulder is lifted the pulley is revolved by the pull rope of acorresponding angle. The pulley f participates in this revolving movement so that the chain .2 is wound upon the pulley f whereby the rod 2 is lifted in the direction of the arrow 1. Herefrom results that the arms 00' are also turned upward in the direction of the arrow IT whereby the pivot bolt n and consequently the artificial forearm are turned in the direction of arrow 111. As the rod is however also connected with the connecting rod u and as this rod is hingedly connected with rod 72 these rods are lifted in linear direction (arrow IV). This movement has at first no consequences until the stud p enters the inclined part of the slot 0. At this'moment the automatic lifting movement of the forearm is terminated. The stud p which continues to move in the same direction will now make the arm 9' turn in the direction of arrow V and. with it the cross g or the artificial upper arm attached to the same.- This artificial upper arm is however lifted by the rods Z connected with the cross 9' which. cause, owing to their connection with the pivot bolt a, the simultaneous oscillation of the forearm and of the upper arm in the direction of arrow VI.

the direction to the forearm and adapted to be put under tension by the lifting of the shoulder" the combination of a. pull rope made fast with one end to a fixed point of the body and withthe other end to the fore arm, with pulleys having their. geometrical axes of rotation coinciding with the axis of rotation of the artificial shoulder joint,.and

means for stopping this bending; movement.

2. An artificial: arm of'the type described and shown comprising in combination with a pull rope attached with one end to a: fixed point of the human'body and with the other end to the forearm, a large rope pulley, and

a small rope pulley, the axle upon which said rope pulleys are mounted situated in the axis of articulation of the shoulder joint, a straight guide for the pull rope, a pivot bolt for the forearm, a pair ofarms connected' with said pivot bolthaving slots and designed to; transfer the angular rotation of the rope pulleys to theforearm for making the same oscillate, a jointedcrossmounted. upon said axle of the shoulder joint, a slotted arm of said joint cross, a linear guide link upwardly extending from the pivot bolt of the forearm, an arm of said linear guide link, a stud projecting from said arm engaging with'said slotted arm of the joint cross so that the joint cross is partly revolved, and rods rigidly connecting said joint cross with said pivot bolt for transferring the part rotation of the joint cross to the artificial forearm for'oscillating' the same together with the artificial upper ELI'IH.

In testimony whereof I affix my signature in presence of two witnesses.

' DUNCAN" MACKENZIE ANDERSON; Witnesses:

H. Bnonnw, EMILE BLOUIN'.

I lit)

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