US2707478A - Crutch - Google Patents

Description

May 3, 1955 R. G. DAVIES CRUTCH Filed Jan. 14, 1952 oe oag i Fig 2.

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mvmon Roland Gwynne Davies BY T2 ATTORNEY United States Patent CRUTCH Roland Gwynne Davies, Leeds, England Application January 14, 1952, Serial No. 266,272

Claims. (Cl. 135-52) This invention relates to crutches and is directed to the provision of a crutch which is more comfortable in use.

Usually crutches are constructed having an upright or limb of two or more struts, the handle being between two struts and parallel with the body of the user. The shoulder rest, which is shaped so as to be placed under the armpit in use, is a rigid part of the crutch and invariably causes chafing and soreness. Such shoulder rests generally comprise rubber or like pads, but although such material affords comfort for a short time, if the crutch is in constant use, the shoulder rest causes discomfort due to the pressure under the users armpit. Also the flow of blood and lymph through the area about the armpit may be impeded, causing further discomfort. Such pressure is caused by the design of the crutch, which causes the users shoulder to rise as it swings forwardly about the foot of the crutch, and by the fact that all the thrust is transmitted up the crutch limb directly under the armpit.

It is the main object of this invention to provide a crutch which will not place any real strain on the users shoulder and thus may be used over long periods without undue discomfort.

More specifically, an object of the invention is to provide for permitting substantially level transition of the user's shoulder in moving forward with the crutch rocking on its lower end as a pivot.

Other objects of the invention will appear to persons skilled in the art to which it appertains as the description proceeds, both by direct reference thereto and by implication from the context.

According to the present invention, there is provided a crutch embodying a shoulder rest capable of downward movement relative to the crutch limb. The construction may be such that at least the shoulder-receiving part of the rest is wholly or mainly behind the crutch limb. The rest may be pivotally or slidably or otherwise depressibly mounted.

There may be provided a crutch including a limb, a hand grip fixed to said limb, and a movable shoulder located wholly or partly rearwardly of the limb, said shoulder rest being spring loaded to resist downward pressure.

The spring means may be anchored to the limb of the crutch and to a forward extension of the shoulder rest pivotally attached to the upper part of the limb. Also said pivot may comprise a ball or universal joint. The hand grip preferably extends sideways from the limb to enable the user to grip it and rest the body weight thereon, more easily.

The above-described device of this invention in use places most of the strain of walking upon the arms, especially the forearm, thus taking the strain away from the shoulder. The provision of a shoulder rest that will give under pressure allows for the guidance of the crutch by the shoulder and yet takes the strain away from under in said drawing,

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it and places it on the arms, and some, but reduced, pressure on the front part of the shoulder.

Referring to the accompanying drawing in which like numerals of reference indicate similar parts throughout the several views:

Figure l is a side elevation showing my improved crutch with the shoulder rest in normal position;

Figure 2 is an elevation looking at the right of Fig. 1,

and at the front of the crutch as preferably used;

Figure 3 is a top View;

Figure 4 is an enlarged view of the upper end of the crutch showing the shoulder rest and its mounting on the limb;

Figure 5 is a diagrammatic view showing the arc A of travel of the upper end of the crutch limb and several positions assumed in use by the shoulder rest with an oval S thereon representative of a shoulder, and a horizontal line H for showing the substantially horizontal transition of the shoulder as the shoulder and crutch move forwardly in use.

In the particular embodiment of the invention shown the reference numeral designates a limb or upright portion of a crutch, which may be made of tubular material of a required length to suit the height of the user. The basal end is fitted with a rubber pad 11 or other device to prevent slipping when in use. At about midway in the length of the limb is fixed a hand grip 12, which is preferably, but not necessarily, adapted to extend laterally and arranged so as to extend slightly back from right angles to the body of the user. Holes 13 at intervals in the limb enable the handle to be adjusted for height. Also the limb may be made of telescopic tubular sections secured by a removable stud 14 in one of another series of holes 15 in the limb to allow adjustment in the height or length of the limb to suit the user.

A spring-loaded shoulder rest 16 is pivotally mounted at the top of the limb It). For that purpose a stud 17 is shown with a neck 18 depending into the upper end of the tubular stock comprising the limb, said stud having a flange 19 to rest upon said upper end of the limb and having an upwardly projecting stem 20 to constitute the fixed hinge member for the pivotal mounting. The shoulder rest 16 has a downwardly directed hinge member a, 21 overlapping said fixed member and hinged thereto by a pivot pin 22. One form of spring-loading comprises a pair of longitudinally coiled springs 23 secured at their lower ends at the front of the crutch by a yoke 24 attached at its middle by a screw 25.fast in the limb. The upper ends of the springs hook into eyelets 26 depending from the shouder rest forwardly from the pivotal mounting thereof. The springs have sufiicient tension to nearly support the weight normally applied by the user on the shoulder rest, taking into consideration the leverages involved.

The shoulder rest has a greater length of projection rearwardly than forwardly from its pivot and is of curved formation, here shown as having an upwardly curved forward end 27 and an upwardly curved rear end 28 and with the up-curved rear end longer than the up-curved forward end. These curvatures form a good seating for the front and rear of the users shoulder next the armpit. Furthermore the shoulder rest is provided with suitable padding to form a good seating for the users shoulder. The rest is of narrow formation so as not to be objectionable under the armpit, and its greater length to the rear is to enable the users shoulder to be supported thereon wholly or mainly behind the limb.

The shoulder rest may have a permitted twist or rotation about the axis of the limb if so desired, and for this purpose a slot 29, extending in a circumferential direction, is provided near the top of the limb in the region occupied by the neck 18 of stud 17, and a screw 30 passing through said slot and fixed in the said neck keeps the stud assembled upon the limb but permits the desired rotation. Furthermore, the amount of vertical swing of the shoulder rest may be limited, and this limitation may be made adjustable by an adjusting screw 31 interposed between the stud and rest. Also, adjustment of spring tension may be included, for instance by providing a choice of holes in the limb for screw 25 by which the spring yoke 24 is attached. If desired, the springs may be enclosed in the limb or an associated part.

The limb need not be tubular, but may be a rod or bar of desired section, for instance, round, rectangular, T or U-shaped, a simple angle or the like. The upper part of the limb may be shaped or otherwise provided with means to accommodate the shoulder rest to pivotally mount the same.

A crutch having a movable shoulder rest as above described will allow the shoulder of the user to sink when pressure is applied so that the shoulder does not ride forcibly upwardly, as with an ordinary crutch, along the arcuate path indicated by are A in Fig. 5. Instead, when the crutch is swing forwardly, the shoulder sinks and goes forwardly and thus the real strain can be taken on the arm of the user. The only real increase in pressure on the shoulder will be on the front firmer part and thus there is freedom from severe pressure and chafing under the armpit. It may be further pointed out, that as the shoulder rest swings under applied weight or pressure of the user, the springs stretch and this might be assumed at first glance as disturbing the balance be tween applied pressure and spring pressure. However, the swinging of the rest moves the springs laterally toward the pivot which therefore increases the leverage 2.

ratio to the advantage of the applied force of the user in overcoming the increased tension of the springs. Thus the users shoulder will move forwardly substantially on a horizontal line H as indicated in Fig. 5.

I claim:

1. A crutch comprising a limb, a shoulder rest at the upper end of said limb, a stud interposed between the said limb and shoulder rest, a pivot transverse to said stud mounting said shoulder rest pivotally on said stud, and means holding the stud assembled with the limb, said stud having a limited rotational attachment to the limb by said holding means, and said holding means and stud cooperating with said pivot for permitting a pivotal teetering of said shoulder rest and permitting a rotational movement of the shoulder rest about the longitudinal axis of the limb.

2. A crutch in accordance with claim 1 wherein a stop is provided for limiting downward pivotal movement of the shoulder rest in one direction of teetering of said rest.

3. A crutch comprising a limb, a movable shoulder rest at the top of said limb, and a handle at the side of said limb, said handle having an outward rearward slopc from the limb in relation to the limb in its normal position of use and said handle and limb having cooperating means securing the handle to the limb with said slope predetermined and invariable.

4. A crutch comprising a limb, a shoulder rest having a pivot intermediate of its ends mounting said rest pivotally upon and above the upper end of said limb, said rest having forward and rearward portions extending uneven distances forwardly and rearwardly of said pivot, and spring loading applied to the shorter of said portions at a distance from said pivot such that the angle of the spring axis to the limb decreases as swing of the shoulder rest increases tension on the spring, whereby the users shoulder may have forward motion in use of the crutch in substantially a horizontal line chordal to the arc of: swing of the upper end of the limb with a substantially constant resistance to depression effective on the longer said portion of the shoulder rest.

5. A crutch comprising a limb, a shoulder rest having a pivot intermediate of its ends mounting said rest pivotally upon and above the upper end of said limb, said rest having forward and rearward portions extending uneven distances forwardly and rearwardly of said pivot, and spring loading applied to the shorter of said portions at a distance from said pivot such that the angle of the spring axis to the limb decreases as swing of the shoulder rest increases tension on the spring, whereby the users shoulder may have forward motion in use of the crutch in substantially a horizontal line chordal to the arc of swing of the upper end of the limb with a substantially constant resistance to depression effective on the longer said portion of the shoulder rest and a stop between said short portion of the shoulder rest and the limb in opposition to direction of swing imposed by said spring loading.

References Cited in the file of this patent UNITED STATES PATENTS 254,348 Maine Feb. 28, 1882 1,183,008 Hipwood May 16, 1916 1,244,928 Walters Oct. 30, 1917 2,568,654 Neptune Sept. 18, I951 FOREIGN PATENTS 176,777 Canada May I, 1917

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