US2665701A - Crutch - Google Patents

Description

n- 12, 1954 c. K. THACKERAY CRUTCH Filed Jan. 22, 1949 INVENTOR 6. 7Z4k ay BY I ATTORNEY Patented Jan. 12,1954

CRUTCH Charles K. Thackeray, Stamford, Conn., assignor to Rehabilitation Center for the Physically Handicapped, Incorporated, Stamford, Conn., a corporation of Connecticut Application January 22, 1949, Serial No. 72,163

3 Claims.

This invention relates to a crutch, and more particularly to that class of crutch equipped with a prong or other device whereby the crutch may be used with safety on slippery icy surfaces. Crutches of the particular class are well known in the art, but none of the prior art crutches have been commercially successful because of cumbersome, heavy and complicated constructions which have required complete and expensive variations of the usual crutch structure.

It is the object of my invention to contribute a crutch of the class described that will be very simple and inexpensive to manufacture, and will follow very closely the construction of the usual commercial crutch now well known in the art.

As one feature of my invention, I form one of the usual bowed legs of a crutch with a groove, preferably on the surface, that readily lends itself to covering by a simple wood strip, and then mounting the prong operating means in this groove where they are confined by the wood strip against flexing outwardly of the groove.

As a further feature of my invention, I use for my operating means a long thin rod adapted to slide in the groove. It is quite obvious that this rod, even though preferably quite thin so as to permit flexing thereof when required, will accept considerable endwise pressure and will resist endwise movement because of the shape of the groove in which it lies. Therefore, the rod lends itself admirably for use in transmitting motion from a handle to a prong or the like, the handle being mounted crosswise in the usual fashion between the bowed legs of the crutch, while the prong preferably rests entirely within the foot formed by the usual union of the two bowed legs of the crutch.

As a further feature of my invention, the handle is adapted to rotate a cam, the cam in turn moving the rod endwise in its groove. By particularly forming the cam, rotation of the handle in either of opposed directions will move the rod effectively. As a particular feature of this part of the invention, the cam is equipped with a detent surface whereby it is interlocked with the rod, holding the rod in a downward effective position while the rod in turn holds the cam and handle against rotation.

A further feature of the invention resides in the utilization of a prong mounted in the foot of the crutch and spring pressed upwardly out of operating position by a spring, the spring in turn holding the prong against the operating rod.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that fol lows may be better understood, and in order that my contribution to the art may be better appreelated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the are will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims to be granted me shall be of sufiicient breadth to prevent the appropriation of my invention by those skilled in the art.

Referring now to the drawings, Fig. l is an elevation and partial section of a crutch embodying my invention. Fig. 2 is a section taken along lines 2-2 of Fig. 1. Fig. 3 is a view of the parts of Fig. 2 with the handle cam rotated Fig. 4 is an enlarged section showing the method of mounting my handle for rotation relatively to one of the legs of the crutch. Fig. 5 is a section taken along lines 5-5 of Fig. 1.

Referring now more particularly to the drawings, my crutch is formed of a right bowed leg l0 and a left bowed leg H meeting at l2 to form a foot. At their upper ends the legs H], H are joined by an arm support I3. A handle it is provided, and is positioned in the usual manner well known in the art between the bowed legs l0, H. The handle I4 is adapted for rotation relatively to the bowed legs and for that purpose is formed with a bore l5 through which extends a rod 16 headed at both ends at I! relatively to the bowed legs 10, ll. Preferably, a washer I8 is fitted between each head I! and each of the two legs. It is quite obvious that the hanclllse M will rotate readily relatively to the rod .The leg H of my. crutch, as shown in the several figures, is formed with a groove l9 leading from the lower end of the bowed leg I I upwardly to the point where the handle I4 is mounted for rotation. For covering the groove, I preferably use a strip of wood 20 that may be glued or otherwise fastened in position as will. be readily apparent. Within the groove 19 I mount a long thin and flexing rod 2!, this rod being adapted for sliding movement within the groove l9 as is quite obvious. Because of the bowed nature of leg II and the consequent form of the groove l9, rod 2| will be held frictionally against movement in the groove I 9 while bending to conform to the groove. Moreover, it is obvious that the relatively thin rod 2] will be capable of accepting a great deal of end pressure because of the manner in which it is mounted.

The bowed leg H is formed with an opening 22 communicating with the upper end of the groove 19, and rotating in this opening 22 is a cam 23 that is fixed to the handle M by a pair of screws 24. Cam 23 is so shaped that when rotated by the handle I4 relatively to the opening 22, it will effect linear movement of the rod 2| as is best seen in Figs. 2 and 3. It will be noted further that the cam 23 is heart-shaped and that it does not matter whether it is rotated clockwise or counter-clockwise by handle l4. Cam 23 is preferably equipped with a detent notch 25 whereby when the cam occupies the position of Fig. 3, it is yieldingly held against rotation by the rod 2|. It in turn holds the rod 2| against upward movement to the position of Fig. 2. Therefore, it may be said that the rod and cam are in mutual retaining relation when they are positioned as shown in Fig. 3.

The foot |2 of the crutch is formed by the union of legs H), H and is covered by the usual rubber member 26, this member 26 being here shown with a bore 27 for a prong 28. Prong 28 rests in a bore 29 formed in the foot i2 and in communication'with the bore |9 of leg A spring 39 operates between the shoulder 3| of prong 28 and a washer 32 carried by the rubber member 26. It is thus the function of the rubber member through the washer 32 and spring 39 to maintain the prong 28 in its position of Fig. 2.

In operation, the prong will be maintained normally as in Fig. 2 by spring 3|), while rod 2| is held upwardly by friction. When it is desired to extend the prong, the handle may be rotated in either of opposed directions from the position of Fig. 2 to the position of Fig. 3. The rod 2| and the cam 23 are now in mutual retaining relationship and the prong 28 is extended for use. Upward endwise thrust will be readily accepted by the rod 2| and cam 23 to hold the prong extended. When it is desired to allow the prong to return to its position of Fig. 2, the cam 23 is rotated to its position of Fig. 2. Then with the application of pressure to the prong 28, the prong will move upwardly to the position of Fig. 2 and will carry with it the rod 2|. Thereafter, friction will hold the rod 2| in position while the prong will be maintained in position by the spring 30. My invention is so arranged that pressure must'preferably be applied to the prong 28 to move the rod 2| upwardly to its position of Fig. 2, the pressure exerted by spring 3|] being very slight. Therefore, the spring cannot function to move the parts back to the position of Fig. 2 from Fig. 3. Spring 30 is of sufficient power, however, to maintain the prong itself in the position of Fig. 2 once pressure has been applied to move the rod 2| to that particular position.

I believe that the construction of my invention and the rather considerable contribution I have made to this highly developed art will now be apparent to those skilled in that art.

I now claim:

1. In a crutch of the class described, a pair of bowed legs joined at their lower ends to, form a foot, a handle rotatably mounted on said legs in cross-relation thereto, one of said legs having a surface groove therein, a relatively thin flexing rod in said groove extending between said foot and handle and per se incapableof accepting the compressive force required for supporting the weight of a person thereon, a covering strip secured to said leg in covering relation to said groove to form with said groove an internal bore for said rod, said covering strip and said groove being of such size and form that said bore formed therebetween confines said thin rod for movement axially of its length within said bore in the path determined by said bore and holds Gil the rod against flexing relatively to said bore upon the application of linear compressive force against said rod, said rod thereby becoming effective to accept linear compressive force, a prong in said foot engaged with said rod for applying linear compressive force against the said rod when said prong extends beyond said foot, and means whereby rotation of said handle moves said rod linearly in said groove to effect movement of said-prong relatively to said foot between a position inwardly of said foot and a position outwardly of said foot.

2. In a crutch of the class described, a pair of bowed legs joined at their lower ends to form a foot, a handle rotatably mounted on said legs in cross-relation thereto, a covering strip applied to the outer surface of one of said legs, said strip and said one of said legs having internal cooperating surfaces forming therebetween an internal bore, .a relatively thin flexing rod in said bore extending between said foot and handle and per se incapable of accepting the linear compressive force required for supporting the weight of a person thereon, said bore being of such size as to confine said thin rod for movement axially of its length within said bore in the path determined by said bore and to hold the rod against flexing relatively to said bore upon the application of linear compressive force against said rod, said rod thereby becoming eifective to accept linear compressive force, a prong in said foot for applying linear compressive force against the said rod when said prong extends beyond said foot, and means whereby rotation of said handle moves said rod linearly in said groove to effect movement of said prong relatively to said foot from a position inwardly of said foot to a position outwardly of said foot.

3. In a crutch of the class described, a pair of bowed legs joined at their lower ends to form a foot, a covering strip applied to the outer surface of one of said legs, said strip and said one of said legs having internal cooperating surfaces forming therebetween an internal bore, a relatively thin flexing rod in said bore and per se incapable of accepting the linear compressive force required for supporting the weight of a person thereon, said bore being of such size as to confine said thin rod for movement axially of its length within said bore in the path determined by said bore and to hold the rod against flexing relatively to said bore upon the application of linear compressive force against said rod, said rod thereby becoming effective to accept linear compressive force, a prong in said foot for applying linear compressive force against the said rod when said prong extends beyond said foot, and means for moving said rod linearly in said groove to effect movement of said prong relatively to said foot from a position inwardly of said foot to a position outwardly of said foot.

CHARLES K. THACKERAY.

' References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 404,303 Remillard May '28, 1889 1,127,893 Hover Feb. 9, 1915 1,257,181 Bradford Feb. 19, 191.8 1,441,317 Walsh et a1. Jan. '9, 1923 1,748,875 Fisher Feb. 25, 1930 2,088,786 Gilbert et a1. 'Aug. 3, 1937 2,376,282 Schroeder May 15, 1945 2,437,076 Clemens Mar. 2, 1948

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