US2544957A - Crutch - Google Patents

Description

March 13, 1951 N- R, HENRY y 2,544,957

CRUTCH Filed Aug. 2, 1948 ATTORNEYS.

Patented Mar. 13, 1951 UNITED STATES PATENT.' FF'CE CRUTCH Nelson R. Henry, Atlanta, Ga., assignor to Joseph'C. Watters, Atlanta, Ga.

n Application August'Z, 1948, Serial N."41,'990

3 Claims. l K

This invention relates to a telescoping crutch. More particularly, the invention has reference to a telescoping crutch construction wherein a leg member can be adjusted longitudinally of a frame section, a novel means being provided whereby said member and section are locked against movement relative to each other after the adjustment is made.

A telescopic crutch is not in and of itself new, such a crutch being shown in Patent Number 2,426,074, to Joseph C. Watters. The main purpose of the present invention is to provide, in such a crutch, an improved locking arrangement wherein the cooperating lock means on the leg member and frame section respectively can be brought into engagement by the simple expedient of giving a one-quarter turn to the leg member; wherein they can be disengaged with the same ease; and wherein, when said lock means are in engagement, they will cooperate to hold the leg member and frame section both against relative rotatable and relative slidable movement.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts, hereinafter more fully described vand pointed out in the claims, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

Referring to the drawings:

Figure 1 is an elevation of a crutch constructed in accordance with the invention.

Figure 2 is an enlarged fragmentary view, partly in elevation and partly in vertical section, through the lower portion of the crutch, the parts being shown in locked engagement.

Figure 3 is a perspective view of a lock collar carried by the leg member.

Figure 4 is a perspective View of a cambered spring washer positioned in a socket member that is carried by the frame section.

Figure 5 is a perspective View of the socket member.

Figure 6 is a perspective view of a, clamping shoe.

Figure '7 is a plan view of a clamping ring, in which the clamping shoe is mounted.

Referring to the drawings in detail, the crutch includes a shoulder rest 8, parallel side frame members 9 rigidly secured at their upper ends to the shoulder rest, and a guide sleeve Ill to which the coverging lower ends of the side frame members are rigidly secured. A hand hold II is as bolts or the like.

The parts so far 'described together constitute the frame section of the crutch.

Slidably mounted in lthe guide sleeve It is the tubular leg member'l comprising the-movable or telescoping section of the crutch. 1 In the position of the parts as illustrated in Fig.' 1, the leg member is telescoped into the-frame section for its full length.

Mounted on the leg'member I3 is a lockv collar i I4, having aligned openings I5receiving fastening means I6 preferably comprising a y'bolt and self-locking nut. VSpaced longitudinally of the leg member is a series'ofi openings I1 and'thus it can be observed that the lock collar -I4 is adapted to be secured to the leg member I3 in selected positions of adjustment longitudinally ofthe leg member. Y

The lock collar I4 vis preferably -split longitudinally as shown atf'l8, for tighter clamping in adjusted positions to the leg member, andat its lower end is integrally formed with a squared flange or shoulder I9 from two sides of which extend opposed arcuate'ribs 20. The upper surfaces of the ribs 20 are disposed in a lower plane than the upper surfaces ofthe' portions of the shoulder I9, as best seen from Fig. '3. 'The corners of the shoulder I9 are preferablyL rounded off as at 2l, said rounded corners merging into, and conforming to the curvature of, the ribs 2Q.

Integrally formed with the upper endA of the guide sleeve I 0 is a cup or socket member 22 through which the leg member I3 extends, and which is of greater diameter than the leg member to provide a space for receiving shoulder I9 and ribs 20 of the lock collar I4. Extended inwardly from the side wall of the'cup 22 at the upper or outer end thereof, arer diametrically opposed shoulders 23vand these, when viewed in plan, have substantially the same conformation as the arcuate ribs 20. The inner edges of the shoulders 23 are straight and parallel, and are spaced apart a distance substantially equal to the distance between any-two opposite sides' of the shoulder I9 of the lock collar I4.

An opening 24 is formed in thev cup v22, and through this opening is extended the tongue 25 of a cambered spring washer 26, so asi-to hold the spring washer against rotatable movement in the cup. The raised portions of--the-spring it washer 26 are disposed below the shoulders 23, as best seen from Fig. 2.

Assuming that the crutch is to be prepared for use by one having need of the same, the lock collar I4 will rst be adjusted longitudinally of the leg member I3, so that when thelock collar is engaged in the cup 22, the overall length of the crutch will be adjusted exactly for said person. Ordinarily, as long as the crutch is to be used by that particular person, the lock collar I4 would not be again adjusted along the leg member.

To extend the crutch for use, the leg member I3 is now withdrawn through the guide sleeve Iii, and the lock collar I4 entered into the cup 22. In entering the lock collar, the user positions it so that the ribs 2! are disposed between the shoulders 23 of the cup since obviously, the collar could not be entered into the cup if the ribs were positioned otherwise. The lock collar is now drawn into the cup against the action of the spring washer 26, until the upper surface of shoulder I9 clears the undersides of the shoulders 23. Now a one-quarter turn is given to the lock collar by rotating the leg member I3 and when this is done, the lock collar will snap upwardly into the position illustrated `in Fig. with ribs 2li engaged under shoulders 23, and the flange I9 engaged between the straight inner side edges of said shoulder. The engagement of ribs 20 under the shoulders holds the leg member and frame section against relative slidable movement while the crutch is in use, and the engagement of flange i9 between the shoulders holds the leg member and frame section against relative rotation. The spring washer 26 retains these locking means, in engagement.

It may be noted that during regular use of the crutch, there would be no appreciable tendency of the locking means to become accidentally disengaged. This is due to the fact that a downward pressure is exerted through the side members described above, I provide an enlarged opening` 21 in the guide sleeve I0 near the lower `end thereof. An arcuate vshoe 2d iits loosely in this opening, and the inner surface of the shoe is adapted to engage the surface of the leg member I3. A knurled clamping ring 21 is iitted upon the guide sleeve I0, rather loosely. The clamping ring 29 is concentric with the guide sleeve and leg member I3, but has formed in its inner surface an eccentric groove 3i) receiving the shoe 28.

It will be observed as a result of this construction, rotatable movement of the clamping ring in one direction will wedge the shoe 28 tightly between the ring and the leg member I3, so as to provide a clamp for the leg member. Rotation of the ring in the other direction will break the clamping action of the shoe. The shoe of course, being disposed partly in opening 21 and partly in groove S, holds the clamping ring mounted to the guide sleeve.

When it is desired to bring the parts to the inoperative position of Fig. l, the clamping ring 29 is loosened. Then, lock collar I4 is released from collar 22 by pulling downwardly on the leg member, and giving a one-quarter turn thereto 4 in either direction, as a result of which the collar I4 is freed from cup 22.

A rubber tip 3I is fitted onto the lower end of the leg member I3, for engagement with a supporting surface.

Advantageous characteristics of the construction may now be noted. The user, when he desires to collapse the crutch, does so by the simple expedient of giving a partial turn to the clamping ring 29 and to the leg member I3, after which the crutch is collapsible to half its normal length. When the user again desires to extend the crutch, the same operation is followed, in reverse. When the crutch has been extended, and the parts engaged as in Fig. 2, a completely rigid lock, that cannot be accidentally disengaged or loosened, results.

It may be observed that the clamping ring and shoe not only serve as a supplemental lock when the main lock means is engaged, but also discharges the function of locking the leg member and frame after the leg member is telescoped to the position oi Fig. l.

What is claimed is:

l. A crutch including relative rotatable and slidable frame and leg sections, a lock collar carried by the leg section, a non-circular flange on the collar, opposed ribs extended from the ange, a socket member carried by the frame section, opposed shoulders on the socket member the side edges of which define between them a space of non-circular shape into which said ange nts to engage the iiange to hold said sections against relative rotatable movement, said ribs being so located relative to the flange that tting of the ange into said space causes the shoulders to overlie the ribs to hold the sections against relative slidable movement, and means interposed between the collar and socket member yieldably holding them interengaged comprising a cambered spring washer anchored against rotation in the socket member and having diametrically opposed raised portions respectively underlying said shoulders of the socket member to exert pressure against the ribs when said ribs underlie the shoulders.

2. A crutch including relatively slidable and rotatable leg and frame sections, a lock collar on the leg section, means for adjusting the collar longitudinally of the leg section, a square flange on the collar, a pair of arcuate ribs extended from opposite sides of the flange and disposed in a plane offset from the plane of said square flange, a socket member on the frame section, opposed shoulders having straight side edges extended inwardly from the side wall of the socket member at diametrically opposed points thereof, the side edges of said shoulders dening between them a space into the plane of which the square iiange can be iitted to hold the sections against relative rotation, said shoulders adapted to overlie the ribs when the shoulders and flange are coplanar, and a cambered spring washer anchored against rotation in and relative to the socket member and having diametrically opposed raised portions respectively disposed under said shoulders to press said ribs against the undersides of said shoulders.

3. A crutch including a frame section, a socket member rigid with the lower end thereof, a leg member slidably and rotatably mounted in the socket member, a square flange rigid with the leg member, opposed arcuate ribs rigid with and extending laterally from the ange at opposite 7| sides thereof, said ribs being in a plane oiset from the plane of said square ange, the socket member having a ared end, inwardly extended` shoulders formed upon the flared end of the socket member, said shoulders having parallel straight side edges dening between them a spawj the side limits of which are straight and paralv l' and spaced apart a ditsance sufficient to engage the square -ange when said ilange is moved into the plane of said space, to hold the frame and leg sections against relative rotatable movement',

said shoulders adapted to overlie the ribs when said flange is co-planar with and engaged by the` side edges of said shoulders, to hold said sectio against relative sliding movement, and yielding'`-` means interposed between the` ribs and socket member to releasably hold the flange. ribs, arid shoulders interengaged, said yielding means corri;4 prising a cambered spring washer seated within the flared end of the socket member and below4 REFERENCE S CITED The following references are'of record in the le of this patent:

lUNITED STATES PATENTS Number Name Date 1,194,793 Styers Aug. 15, 1916 1,232,193 Bowes, Jr. July 3, 1917 Watters Aug. 19, 1947

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