Patent Application
20060219280
1. Field of the Invention
The present invention relates generally to a sliding device, and in particular to a sliding foot assembly for engaging a support leg of a walker.
2. Discussion of the Related Art
Presently, a number of different types of walkers have been developed to assist aging and disabled persons. Such walkers enable users to stand and walk relatively freely across level and moderately inclined ground, as well as up and down stairs. Conventional walkers require both strength and stability because an invalid user, for example, must rely upon the walker as their sole or primary source of support. Such walkers are often lightweight, and constructed of an arrangement of aluminum tubing frames.
Many walkers have three, four, or more legs. Each of the legs is generally equipped with a device, such as a wheel or rubber foot, which makes contact with the ground. The wheel or rubber foot provides two primary functions. One function is to provide stable support to the walker, and consequently to the user of the walker. Another function is to allow the user to advance or otherwise move across the ground with minimal effort. Existing devices have made strides to achieve these functions, but improvement is still needed.
In accordance with one embodiment, a foot assembly of a unique shape for use with a walker may include an attachment assembly for engaging a leg tube of the walker. The attachment assembly may be designed to accommodate walker legs with varying inside diameters. A coupling device, such as a screw, may be used to couple the attachment assembly with the uniquely shaped slider foot. The coupling device permits rotational and angular movement between the attachment assembly and the slider foot. In some embodiments, the walker may include three or four legs which are connected by a structure which maintains the legs in a fixed spatial relationship. A separate foot assembly may be affixed to one or more of the legs of the walker.
The above and other aspects, features, and advantages of the present invention will become more apparent upon consideration of the following description of preferred embodiments, taken in conjunction with the accompanying drawing figures, wherein:
In the following detailed description, reference is made to the accompanying drawing figures which form a part hereof, and which show by way of illustration specific embodiments of the invention. It is to be understood by those of ordinary skill in this technological field that other embodiments may be utilized, and that structural, as well as procedural, changes may be made without departing from the scope of the present invention.
As a matter of convenience, various embodiments of the invention will be described in the context of a four-leg walking device which implements a walker foot assembly coupled to one or more of its legs. However, the teachings of the present disclosure are equally applicable to walking or support devices (for example, three-leg and four-leg walking canes) for which relatively smooth movement along a surface is desired. Furthermore, various components of a walker foot assembly will be described using exemplary materials, sizes, shapes, and dimensions, but the present invention is not limited to the stated examples.
One purpose of slider foot 15 is to support attachment assembly 20, along with an attached walker (not shown in this figure). The slider foot permits the walker to easily slide or otherwise pass along a surface. The slider foot may be made from a number of different materials which are sufficiently durable to withstand forces encountered during use, and which permits an attached walker to easily slide across a surface. Specific materials which may be used for the slider foot are discussed below.
The slider foot is shown having a substantially flat bottom portion 55. At a radial distance from central axis 57 of the slider foot, the bottom of the foot begins to angle upward to form angled portion 60, which is an optional feature. The angle between angled portion 60 and a plane parallel to bottom portion 55 is shown increasing as a function of radial distance from the central axis. Angled portion 60 allows the slider foot to encounter and negotiate small objects and obstructions which may be present on a surface. Note that angled portion 60 need not be formed at any particular angle.
Slider foot 15 may include cavity 65, which is sized to receive and contain screw 45 and washer 50. The slider foot also includes a centrally located aperture 70, which receives projection 75 of the tubing retainer. Once assembled, curved surface 80 of the retainer engages cooperating curved surface 85 of the slider foot for slideable relative movement. This arrangement permits relative motion (rotational, angular, or both) between attachment assembly 20 and slider foot 15. The diameter of the projection may be sized to form a gap between the projection and the inner wall of aperture 70. This gap permits the attachment assembly and the slider foot to tilt, and to rotate 360° relative to one another. The tilting aspect will be discussed in more detail in conjunction with later figures.
Tubing retainer 25 is shown formed with annular recess 90, which is sized to receive a lower portion of expansion tubing 30. The upper portion of the expansion tubing may be stabilized using tubing cap 40. In the embodiment of
The slider foot, tubing retainer, tubing cap, screw, and washer may be formed from any sufficiently rigid and durable material (for example, plastic, thermo plastic, metal, alloy, and the like), which permits these components to perform their respective functions as part of walker foot assembly 10. Specific examples of materials which may be used for these components include acrylonitrile-butadiene-styrene (ABS), injection molded ultrahigh molecular weight polyethylene (UHMWPE), and injection molded nylon 6/6 plastic, among others.
Expansion tubing 30 may be formed from a material, such as rubber or a thermoplastic elastomer (TPE), that has sufficient durometer and shore, yet pliable under pressure exerted by tubing retainer 25 and tubing cap 40. Extruded acid-resistant neoprene rubber is one of the many types of materials that may be used for the expansion tubing. Slider foot 15 is preferably made from a low friction materials such as PTFE. There are many suitable such materials.
Furthermore, the attachment assembly and slider foot may also be structured so that they individually tilt at an angle relative to each other. For instance, in
As noted above, no particular size or dimensions are required for the various components of walker foot assembly 10. By way of non-limiting example, the slider foot may be sized so that it has a diameter 105 of about 1.2-4.5 inches, and an overall height 110 of about 0.3-1.3 inches. The overall height 120 of the walker foot assembly may be about 0.75-3.2 inches. In accordance with some embodiments, attachment assembly 20 has diameter 125, which permits this component to be received within a tube leg of a walker (not shown in this figure). Diameter 125 will typically vary in size since the inside diameter of a tube leg of a typical walker also varies. However, in many applications, diameter 125 is about 0.5-1.5 inches. Note further that that the various components are shown having dimensions which are substantially circular, but other geometries (for example, rectangular, oval, and the like), may alternatively be used to meet the needs of a particular application.
It is to be understood that in accordance with some embodiments, slider foot 15 and attachment assembly 20 may be structured so that they individually rotate and tilt relative to each other. This aspect allows the walker foot assembly to more-easily encounter and negotiate uneven surfaces, small objects, and obstructions which may be present on a surface. If desired, the walker foot assembly may alternatively be constructed so that it only provides the above-described rotational movement but does not have the tilting feature. Another alternative is to construct the walker foot assembly so that it only provides the tilting feature, but does not have the rotational feature. Yet another alternative is to construct the walker foot assembly so that it is essentially fixed, such that the attachment assembly and the slider foot neither rotates nor tilts with respect to each other.
Note that leg end 160 is in contact with an upper portion of tubing retainer 25. Specifically, the leg end contacts one of three tiered portions of the tubing retainer. Each tiered portion may be designed to engage a leg tube having a different inside diameter. As shown in
An appropriate device, such as screw 210, may be used to secure assembly 200 to the leg tube. Leg housing 205 and screw 210 collectively form an attachment assembly. Note that this attachment assembly and the slider foot may be tilted and rotated relative to one another in a manner similar to that described above with respect to attachment assembly 20. The leg housing may be formed from the same or similar materials as those used for the tubing retainer, for example.
If desired, screw 210 may be omitted. In such an embodiment, leg housing 205 may be sized so that the inner surface of the leg housing frictionally receives and engages the outer surface of leg 150. Another alternative is to size leg housing 205 so that it may be received within cavity 155, and frictionally engage an inner surface of the leg. To facilitate this frictional engagement, portions of the leg housing may include a pliable material such as rubber.
During use, a user may grasp grips 280, and place their weight onto the walker. To advance, the user may push the walker forward causing the end portions of some or all of the legs to slide along the surface. Since front legs 255 and 260 each include a walker foot assembly, the walker may be advanced along the surface with considerably less effort than that which would be necessary if rubber feet, for example, where used on these legs.
Walkers 250 and 300 may alternatively be constructed using any of the various walker foot assemblies disclosed herein. Although only the two front legs (walker 250) or the single front leg (walker 300) are shown having a walker foot assembly, alternative embodiments may are possible by configuring some or all of the legs of each respective walker with walker foot assembly 10, for example.
While the invention has been described in detail with reference to disclosed embodiments, various modifications within the scope of the invention will be apparent to those of ordinary skill in this technological field. It is to be appreciated that features described with respect to one embodiment typically may be applied to other embodiments. Therefore, the invention properly is to be construed only with reference to the claims.
