US2426594A - Crutch - Google Patents

Description

Patented Sept. 2, 1947 CRUTCH James A. Buell, Vallejo, and Freeman A. Riter, Contra Costa, Calif.

Application October 29, 1945, Serial No. 625,418

(Granted under the act ofMarch 3, 1883, as amended April 30, 1928; 370 0. G. 757) 1 Claim.

This invention relates to crutches and more particularly to crutches of the type used to support persons who have sustained foot or leg injuries.

Objects of the invention are to provide improved crutches in which cushioning means are employed to ease the shock or jolt caused by contact of crutch tips with supporting surfaces; to provide improved crutches which are longitudinally adjustable both as to length between hand hold and tip and as to length between hand hold and shoulder piece; to provide improved crutches in which the shoulder pieces are supported from single uprights; and to provide for carrying out the foregoing objects in a facile, economical and. efiicient manner.

In accomplishing these and other objects of the present invention, we have provided improved details of structure, the preferred forms of which are illustrated in the acocmpanying drawing, wherein:

Fig. 1 is a side elevational View of a crutch embodying the features of the present invention.

Fig. 2 is a longitudinal sectional view of cushioning means employed in the crutch shown in Fig. 1.

Fig. 3 is a longitudinal sectional view of a modified form of cushioning means.

Referring more in detail to the drawing:

There is shown at I, Fig. 1, a crutch embodying the features of our invention. The crutch comprises a leg member 2, a hand-hold member 3 and a shoulder support member 4, having a shoulder piece 5, all preferably formed of light weight metal or other suitable material.

The upper end portion of the leg member 2 is tubular and the hand hold member 3 has a depending portion 6 telescopically received in said tubular portion for longitudinal adjustment with respect to the leg member. Means are provided for retaining the hand hold in longitudinally adjusted position and may conveniently comprise set screws I threadedly engaged with the tubular portion of the leg member.

The hand hold member 3 has a portion 8 adapted to be gripped by the hand of the user and preferably has a single upstanding portion 9 adjacent one side thereof. Preferably the hand hold member is hollow in order to decrease its weight.

The shoulder support member 4 has a tubular portion adjacent its lower end that telescopically receives the upstanding portion 9 on the hand hold member for longitudinal adjustment with respect thereto. Means are provided for retaining the shoulder support member in longitudinal- 1y adjusted position and may conveniently comprise set screws IE] threadedly engaged with the tubular portion of the shoulder support member. The member 4 preferably curves inwardly adjacent its upper end, as indicated at I I, and is connected to the shoulder piece 5 midway of the length of the latter. Preferably the shoulder support member and the shoulder piece are hollow in order to decrease their weight.

Means are provided in the leg member for cushiOIlillg the crutch to ease the shock or jolt caused by contact of the crutch tip with a supporting surface.

As shown in Figs. 1 and 2, the leg member 2 comprises an upper section I2 and a lower section I3. The lower portion of the upper section is tubular and telescopically receives the upper portion of the lower section. The latter has an external shoulder I4 formed intermediate its ends. The upper section I2 has an external screw threaded portion I5 adjacent its lower end. A hollow sleeve I6 is threadedly engaged with the threads I5 and has an internal shoulder I'I formed intermediate its length and cooperable with the external shoulder I4 to limit outward movement of the lower section. Preferably a lock the plug I9 and the upper end of the lower section I3.

Preferably the lower end of the lower section 13 carries a crutch tip 2| which may be of conventional design.

Operation The crutch of our invention may be utilized in the usual manner by a person who has sustained a leg injury. Preferably the crutch is first adjusted in length to suit requirements of the individual who is to use it. The distance between the shoulder piece 5 and the hand hold 8 is adjusted by moving the shoulder support member 4 with respect to the upstanding portion 9 on the hand hold member. The hand hold member is then adjusted longitudinally with respect to the leg member 2,

The cushioning means in the leg member eases the shock or jolt caused by contact of the tip with a supporting surface. At such contact the and retains the lower section within the upper section.

Modification In Fig. 3 we have shown a modified form of cushioning means, in which hydraulic means are provided to cooperate with the spring means and thereby enhance the cushioning effect.

In this modification the leg member comprises an upper section 2| and a lower section 22. The upper section 2| is tubular and has an external collar 2'3 and an internal collar 24 secured thereto adjacent its lower end 'as by the set screws 25. The lower portion 22 is telescopically received within the upper section 2| and has an enlarged portion 26 forming an external shoulder '2? cooperable with the internal collar 24 to retain the lower section within the upper section. A plunger or piston 28 of reduced diameter is formed on the upper end of the lower section preferably integrally therewith.

A'second internal collar 29 is secured within the tubular upper section 2| and a hollow cylinder 3!] is secured thereto and slidably receives the piston 23. A compression spring 3| is provided between the collar 29 and the portion 26 of the lower section 22 to normally-urge the lower section to extended position. Preferably a leather cup 32 surrounds the piston 28 ad- J'acent the lower end of the collar 29. g

The cylinder 30 has a tubular plug 33 fitted into its upper end portion. The plug 33 has radial grooves 34 formed in its upper end. A cap member 35 is threadedly engaged or other-.- wise secured to the upper end of the plug 33 and has a circular bore 36 extending through its face. A valve member 37 is loosely fitted between the face of the cap member 35 and the plug 33. The valve member has a bore 3 3 of small diameter extending therethrough.

A plug 40 is fitted within the upper section 2| to close off the tubular portion.

A suitable hydraulic fluid 4| is placed within the cylinder 30 and may occupy a portion of the tubular end of the upper section 2| external to the cylinder.

When longitudinal force is applied to the leg member, as by an individual placing his weight thereon, the lower section 22 telescopes into the upper section 2|. Such telescopic action compresses the spring BI and forces the piston 28 upwards through the cylinder 36. The fluid 4| is forced upwardly through the tubular plug '33 and through the bore 38 in the valve member 3?! from which it spills into the tubular upper section 2| externally of the cylinder 30. During such upward movement of the piston, the valve member 31 is forced upwardly intoengagement with the under face of the cap 35 and fluid must pass through the aperture 33 which offers considerable resistance thereto. 7

At the start of upward movement of the piston the fluid 4| may flow out of the cylinder through V a series of ports 42, as well as through the bore 38. As upward movement of the piston continues, the piston covers the ports 42, preventing further flow therethrough. The resistance to movement of the piston is increased, since after the ports are closed, fluid may escape only through the bore 38. The effect is thus to permit relatively easy inward movement when the force is first applied to the crutch, but to decrease the ease of movement as the force con-' tinues to be applied. Such an effect cushions the crutch additionally over that obtained by spring action alone.

When force is removed from the leg member, the spring 3| forces the lower section 22 downwardly and thereby pulls the piston 28 downwardly in the cylinder 38. The valve member 3! is drawn downwardly and the fluid 4| may flow back into the cylinder 30 around the sides of the valve member without passing through the bore 38. There is less resistance to such flow and hence the fluid readily returns to the cylinder. The leather "cup prevents leakage of .the fluid into the space below the collar 29. It is thus seen that the hydraulic means cooperates with the spring means to provide an increased cushioning .eifect.

While we have shown but certain embodiments of our invention, it is susceptible to further modification without departing from the spirit of the invention. We do not wish, therefore, to be limited by'the disclosures set "forth, but only by the scope of the appended claim.

The invention described herein may be manufactured and used by or for the Goverm'rent of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. We claim:

In a crutch, an elongated support having a pair of sections, one of said sections being {tubular and telescopically receiving the :other of said sections, stop means limiting the extension of said sections, means forming anabutmentin said tubular section, spring means in' said tubular section engageable with said abutment and said telescopically received'section' urging? said telescopically received section to extended position, a cylinder fixed 'to said abutment and adapted toreceive a hydraulic fluid, a piston fixed to said telescopically. received section "and slidably received within said cylinder, and valve means in cylinder offering greaterresistance' to flow of fluid on inward 'movemento'f' said pistonthan on outward movement, said spring means and said piston and cylinder cooperating to pip vide a cushioning effect when a longitudinal coinpressive force is applied to said support.

Number Name 7 f Date 190,392 Weldon May 1, 1877 2,312,786 Wilson Mar. 2, 1943 2,388,778 Wheeler Nov. 13, 1945 1,609,139

Philpy Nov. so,

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