Crutch Tip With Insert

Abstract

A resilient rubber-like crutch tip is provided with a crutch socket having therewith a generally cup-shaped insert of rigid material. The insert provides a recess for receiving the end of a crutch or the like, with the recess having a non-convex central portion and an outwardly tapering upwardly extending rim portion. As the crutch is tilted during normal use, the crutch end will apply pressures to the insert rim portion which in turn spreads the downward and sideways force components through a large area of the flexible tip socket side walls. In addition, in the embodiment shown, a generally V-shaped annular channel or groove is disposed in the outer wall of the insert to reduce the tendency of the insert to tilt. The neck portion of the tip socket is provided with undulations forming lands and grooves, with the lowermost undulation being a land.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a crutch tip, and more particularly to a tip for application to the ends of crutches and the like which provides an improved action and tip life.

Heretofore, many types of crutch tips have been available commercially and/or have been disclosed to the public. Some of these tips have included a disc-like insert at the bottom of the crutch socket. See the U.S. Pat. to Pratt, No. 960,700 and the U.S. Pat. to Smith No. 3,040,757. While such inserts have, among other things, protected the rubber-like bottom of the socket from wear due to frictional forces created by the usual tilting of the crutch end, they have not adequately protected the sides of the socket, and horizontal forces on the disc have even tended to damage or cut into the tip material.

The present invention solves the aforementioned and other problems, and provides a resilient rubber-like crutch tip with a crutch socket having therewithin a generally cup-shaped insert of rigid material. The insert provides a recess for receiving the end of a crutch or the like, with the recess having a non-convex central portion and an outwardly tapering upwardly extending rim portion. As the crutch is tilted during normal use, the crutch end will apply pressure to the insert rim portion which in turn spreads the downward and sideways force components through a large area of the flexible tip socket side walls. In addition, in the embodiment shown, a generally V-shaped annular channel or groove is disposed in the outer wall of the insert to reduce the tendency of the insert to tilt. The neck portion of the tip socket is provided with undulations forming lands and grooves, with the lowermost undulation being a land.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate the best mode presently contemplated by the inventor for carrying out the invention.

In the drawings:

FIG. 1 is a front elevational view of a crutch incorporating the tip mounted thereon;

FIG. 2 is a central vertical section through the crutch tip with the crutch removed;

FIG. 3 is a perspective view of the tip insert;

FIG. 4 is a view similar to FIG. 2 with a crutch end inserted therein and in a vertical position; and

FIG. 5 is a view similar to FIG. 4 with the crutch end tilted, as during use.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1 of the drawings, the invention is for use in connection with a crutch 1 having an elongated shaft 2 which terminates in a bottom end 3. In the present embodiment, end 3 is shown as curved. A crutch tip 4 is applied to the lower end of the crutch to assist the user and prevent slipping, and provides a unitary outer tip body 5 preferably of molded flexible material, such as a rubber-like composition of about 55 Durometer. Body 5 is shaped to form an elongated upper vertical neck 6 which merges downwardly into an enlarged base 7. Annular concentric grooves 8 or other suitable floor gripping means may also be included on the bottom surface 9 of base 7.

As best shown in FIG. 2, tip 4 is provided with a crutch socket 10 which extends downwardly through neck 6 into base 7. The upper socket walls within hollow neck 6 are formed with undulations comprising alternating crutch-gripping lands 11 and grooves 12.

In accordance with the invention, and referring to FIGS. 2 and 3, a recessed generally cup-shaped insert 13 is disposed in the bottom of socket 10 within base 7 and with the side and bottom walls of the insert firmly encapsulated by the material of the tip body. Insert 13 is provided with an upwardly facing imperforate crutch-end receiving surface 14 having a smooth non-convex central portion 15 which merges into an outwardly tapering upwardly extending rim portion 16. In the embodiment shown, surface 14 is concave curved throughout, and terminates in an annular flat edge 17 which is held downwardly in position by an undercut 18 below the lowermost land 11. Insert 13 is of rigid material, such as high tensile strength molded plastic similar to "Nylon." The insert is formed to provide an enlarged base 19 and an annular peripheral inwardly extending generally V-shaped channel or groove 20 for purposes to be described. In the present embodiment, the upper wall 21 of groove 20 is curved, while the lower wall 22 is straight. In any event, groove 20 receives a complimentary portion of the rubber-like material of the tip body.

As shown in FIG. 4, when a crutch shaft 2 is inserted vertically into tip 4, the land and groove undulations tend to straighten out, and shaft end 3 engages at least central portion 15 of insert 13. As shown, the radius of surface 14 is slightly larger than the radius of end 3.

During use of the crutch, the crutch shaft will be moved by the user between the vertical position shown in FIG. 4 and a tilted position, as shown in FIG. 5. The maximum tilt is usually about 15.degree.. When the crutch is tilted, the crutch shaft 2 will bear downwardly and the angular force components will cause neck 6 to tilt and will also shift crutch end 3 relative to insert 13 so that said forces are applied more to the insert rim portion 16. These forces will then be transferred to the tip body 5. Since the insert recess is larger than crutch end 3, and also because of the outwardly tapered rim portion, the horizontal forces will be spread over a substantial area of the sides of the socket of the body. This will reduce wear previously caused by friction of the crutch end on the socket side walls and by sideways shifting of a thin disc, as in the aforementioned patents.

FIG. 5 shows that base 5 will distort during crutch tilting. In addition, insert 13 will tend to tilt slightly. However, the construction provides means to resist tilting of the insert about a horizontal axis. This means comprises the interlock between groove 20 and the tip body material disposed therewithin.

In the embodiment shown, it is preferable that when the crutch is tilted, crutch end 3 will roll on curved surface 14. However, if crutch end 3 is of a smaller radius then surface 14, the end, which is in more or less point contact with the insert, may tend to shift or slide sideways rather than roll. By providing the lowermost undulations as a land 11 instead of a groove 12, crutch shaft 2 will be gripped at the lowermost possible point relative to insert 13, which will help resist the aforementioned sideways shifting. When a flat-ended crutch is used, the peripheral contact of the end with the curved insert recess shown in the present embodiment should help to prevent such shifting.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

Claims

I claim:

1. A crutch tip comprising, in combination:

a. a unitary flexible tip body having an elongated upper neck which merges downwardly into a base,

b. said base having a bottom surface for engaging the floor,

c. a socket formed in said tip body for receiving the end portion of a crutch,

d. the upper wall of said socket being provided with undulations forming alternating lands and grooves,

e. a cup-shaped rigid insert disposed in the bottom of said socket within said base and with its side and bottom walls generally encapsulated by said tip body,

f. said insert including an imperforate upwardly facing crutch end receiving surface having a generally smooth concave central portion which merges into an outwardly tapering upwardly extending annular portion terminating in a flat edge,

g. a generally V-shaped annular peripheral groove in the side wall of said insert and receiving a complimentary portion of said tip body to resist tilting of said insert when a crutch end disposed in said insert is tilted,

h. and an undercut at the lower end of said undulations and engaging said flat edge to hold said insert in position within the tip body.