This application relates to personal mobility aids, such as walkers. In particular, this application relates to a glide tip or a glide tip assembly for use on or as part of a walker or other personal mobility aid.
Walkers are known in the art as an aid for individuals who require support while walking. When using a walker, an individual grasps the walker at the hand grips, lifts and repositions the walker in front of them, then steps toward the walker while using the walker to support a portion of their weight. During this process, the walker leg tips often come in contact with the floor while the walker is moving forward. Thus, the rear legs can drag if the user does not lift them sufficiently or if the user sets the rear legs down while the walker still has some forward movement. This contact can (1) interfere with smooth, forward movement of the walker, (2) create an unwanted vibration in the walker, and (3) create unwanted noise.
Individuals have attempted to solve these problems by placing a tennis ball on the end of each of a walker's rear legs, as a glide cap. This is done by forming a cross-shaped slice in the tennis ball then pushing the tennis ball over the rear leg tip and onto the walker rear leg. Once the tennis ball is over the tip of the walker leg, the outer surface of the tennis ball, not the walker tip, comes in contact with the ground surface. The tennis ball surface, which is flocked, reduces the friction between the walker rear legs and the ground surface, thus allowing smooth, forward movement and reduced noise. This solution, however, is temporary because continued use of the walker results in wear on the outer surface of the tennis ball. As the wear continues, the problems return.
The present invention relates in one aspect to a glide tip for a leg of a personal mobility aid. The glide tip includes a holder, and a replaceable ball supported on the leg by the holder. The ball may be rotatable relative to the holder about a plurality of axes. The ball may be a sports ball, such as a tennis ball.
This application relates to personal mobility aids, such as walkers. In particular, this application relates to a glide tip or a glide tip assembly for use on or as part of a walker or other personal mobility aid, which can take various different configurations.
The walker 12 shown in
Each front leg 16 is illustrated as including a swivel wheel 28, or caster, for engagement with the ground. The front legs 16, however, may alternatively use a fixed wheel, a conventional walker tip, or any other walker tip device, including a glide tip assembly, for engagement with the ground.
Each rear leg 18 is illustrated as including a glide tip assembly 10. Each glide tip assembly 10 (
As with the typical leg of a walker 12, the lower leg portion 30 (
The holder 50 (
The leg attachment portion 60 has a bore 62 for receiving the lower leg portion 30. The bore diameter of the bore 62 is slightly larger than the diameter of the lower leg portion 30, so that a frictional fit between the bore and the lower leg portion can be the sole means of attaching the holder 50 to the lower leg portion 30. Alternatively, the holder 50 can be secured by fasteners, threads, adhesive, or otherwise. The holder 50 could, of course be alternatively directly connected to the walker leg itself.
The enclosing portion 80 of the holder 50 is joined to the leg attachment portion 60 of the holder by the connecting portion of the holder. In the embodiment shown in
The enclosing portion 80 has a generally hemispherical overall configuration including a domed top wall 82 and a generally ring-shaped side wall 84. The side wall 84 is located at the bottom of the top wall 82 and extends for 360 degrees around the top wall 82. The top wall 82 has two large cutouts or access openings 86 on opposite sides of the arms 72, thus providing the top wall 82 with a C-shaped configuration as viewed from the side (for example, as viewed in
The top wall 82 and the side wall 84 of the holder 50 together define a chamber 90 in the enclosing portion 80 of the holder, for receiving the ball 100. The side wall 84 defines a bottom opening 92 into the chamber 90 for inserting and removing the ball 100. The access openings 86 in the top wall 82 of the enclosing portion 80 of the holder 50 help to enable removal of the ball 100 from the holder 50, as described below.
When the ball 100 is in the chamber 90, the inner surface of the top wall 82 of the holder 50 extends at least partially around the ball 100. The side wall 84 of the enclosing portion 80 is adapted to retain the ball 100 in the chamber 90. The side wall 84 has a lip or ridge 93 with an inner diameter that is less than the outer diameter of the ball 100 at its equator. As a result, the side wall 84 functions as a retaining structure to retain the ball 100 in the chamber 90. A variety of different retaining structures can be used to facilitate retaining the ball 100 within the chamber 90.
For ease of manufacturing, the retaining structure illustrated in
The holder 50, in the embodiment illustrated in
The chamber 90 is sized to allow the ball 100 to move between a first position, as shown in
If the user does not wish the ball 100 to retract into the holder 50, the user may use a lockout mechanism for selectively limiting retraction of the ball. In
The holder 50 is designed to allow the ball 100 to be easily replaceable. As shown in
The glide tip assembly 10 is installed on the walker 12 so that when the ball 100 is in the first position it engages the ground 101 and thus supports the ground engaging portion 36 of the leg 30 spaced apart from the ground 101. When a sufficient downward force, such as the user's weight, is applied to the walker 12, the ball 100 retracts to the second position, bringing the ground engaging portion 36 of the lower leg portion 30 into contact with the ground 101. The ground engaging portion 36 provides a slide resistant interface with the ground 101, increasing the stability of the walker 12 while under load.
During the ordinary course of movement of the walker 12 across the ground surface 101, the ball 100 may be in sliding contact with the ground surface or in rolling contact with the ground surface, depending on the amount of friction between the ball and the ground surface. For example, if the ball 100 is a tennis ball with a flocked surface, then on relatively smooth ground surfaces 101 such as linoleum or tile, the friction between the tennis ball and the ground surface is not sufficient to overcome the friction between the tennis ball and the holder 50 (including the spring 102). As a result, the tennis ball 100 slides across the ground surface 101 when the walker 12 moves horizontally. The flocked surface and the resilience of the tennis ball 100 help the walker 12 to move in a smooth, quiet fashion.
If the tennis ball 100 is used on a relatively rough ground surface 101, such as carpet or concrete, the friction between the tennis ball and the ground surface is greater than the friction between the tennis ball and the holder 50 (including the spring 102). As a result, the tennis ball 100 rolls along the ground surface 101 when the walker 12 moves horizontally. The rolling contact helps the walker 12 to move in a smooth, quiet motion. Further, because the ball 100 is retained within the holder 50 without the use of an axle, the ball rotates about a plurality of axes, allowing the smooth, quiet rolling motion to be achieved in any direction. There is no chatter as might occur with a caster or other device during sideways movement. The rolling (rather than sliding) movement of the ball 100 over the rough surface 101 also limits abrasion of the ball outer covering and thus helps to lengthen the life of the ball as used in the glide tip 10.
If a ball 100 with a different outer surface is used, the nature of contact between the ball and the ground surface 101 may change. For example, if a rubber-surfaced ball 100, such as a racquetball, is used on the aforementioned relatively smooth surface 101, the friction between the rubber surface of the racquet ball and the ground surface is increased and could be sufficient to overcome the internal friction of the ball and the holder 50. As a result, the rubber ball 100 could roll along the ground surface 101 when the walker 12 moves horizontally. Thus, the movement of the walker 12 can be customized by selection of the particular ball or sports ball 100 and/or the tension applied by the spring 102 tension.
The holder 120 shown in
When the holder 140 (
The enclosing portion 170 of the holder 140 includes at least two, and preferably at least three, elongated grip members 172 that attach to and extend outward from the base 160. The grip members 172 are adapted to receive and support a ball 100, such as a sports ball. As illustrated, the grip members 172 are curved with a rectangular cross section (
The ball 100 fits between the grip members 172, which extend at least partially around the ball 100. When the ball 100 is within the grip members 172, the free ends 174 of the grip members contact the ball below the ball's equator, and a portion of the ball extends beyond the free ends of the grip members. Because the grip members 172 contact the ball 100 below the ball's equator, the grip members retain the ball in position relative to the base 160, without the ball falling out or off. The design of the grip members 172 and base 160 can result in the ball 100 being solely in contact with the grip members or being in contact with both the grip members and the base 160. Further, even though the grip members 172 retain the ball 100 in position, they allow the ball to rotate relatively freely within the grip members about a plurality of axes. The embodiment including the grip members 172 illustrates that the ball 100 need not be enclosed or covered for a 360° around.
The shape of the grip members 172 allows the ball 100 to compress partially if a sufficient force is applied. For example, if a sufficient force is applied to the ball 100 in a direction parallel to the axis of the walker leg 30, the force may partially compress the ball 100 against the grip members 172 and/or base 160. Further, the configuration of the grip members 172 and the base 160 allows the ball 100 to be replaced easily.
When the holder 140 is installed on the walker 12, the ball 100 engages the ground 101 and thus supports the ground engaging portion 36 of the leg 36 spaced apart from the ground 101. When sufficient downward force, such as the user's weight, is applied to the walker 12, the ball 100 compresses, bringing the ground engaging portion 36 of the lower leg portion 30 into contact with the ground 101. The ground engaging portion 36 provides a slide resistant interface with the ground 101, increasing stability of the walker 12 under load.
During the ordinary course of operation of the walker, there is a first amount of friction between the ball 100 and the ground surface 101 and a second amount of friction between the ball 100 and the holder 140. As discussed above regarding the first embodiment, if the first amount of friction is less than the second amount of friction, the ball 100 will slide across the ground surface 101. If the first amount of friction, however, is greater than the second amount of friction, the ball 100 will roll across the ground surface 101.
The enclosing portion 220 of the holder 200 includes a cavity 222, a recessed area 224, a collar 226, and a ground engaging portion 228. The collar 226 of the enclosing portion 220 is positioned at the top of the enclosing portion 220 and includes an outer lip 230 and a stem bore 232 for receiving a stem 242 on the grip portion (discussed below). The collar 226 is generally circular in cross-section allowing the adjustment knob 260 fit over top of the collar 226. The stem bore 232 is internally linked to the cavity 222 by the recessed area 224. The cavity 222 of the enclosing portion 220 is configured to receive the grip portion 240 within the cavity. The cavity 222 includes an inner surface 223 which generally conforms with the outer surface 244 of the grip portion 240. When the grip portion 240 is fully positioned within the cavity 222, the ground engaging portion 228 of the enclosing portion 220 extends beyond the grip portion.
The grip portion 240 of the holder 200 has a similar configuration to the enclosing portion 80 in the first embodiment (
The grip portion 240 further includes a stem 242 extending perpendicular from an outer surface 244 of the grip portion 240 and through the stem bore 232 in the enclosing portion 230. The stem 242 includes external threads 252 near its upper end that engage internal threads 262 on the adjustment knob 260. The adjustment knob 260 is cup shaped and includes a stem receiving opening 264 with the internal threads 262, an inner stop surface 266, an outer surface 268 for engagement by the user, and an open end 270. The open end 270 of the adjustment knob 260 is positioned opposite the stem receiving opening 264 and over top of the collar 226 on the enclosing portion 220. The diameter of the open end 270 of the adjusting knob 260 is larger than the diameter of the collar 226, so that the adjusting knob is free to move axially along the collar.
The holder 200 also includes at least one spring positioned to act between the grip portion 240 and the enclosing portion 220. The spring may consist of an elastic device such as a metal or plastic strip or coil of wire, or an elastomer. In the embodiment of
The holder 200 is designed to allow the grip portion 240 to move within the enclosing portion 220 between a first position (
The range of movement of the grip portion 240 and the ball 100 is adjustable by use of the adjustment knob 260. The threaded engagement between the knob 260 and the stem 242 of the grip portion 240 results in the grip portion 240 and adjustment knob 260 moving together within the cavity 222. When the ball 100 and grip portion 240 are in the first position, the stop surface 266 of the adjustment knob 260 engages the collar lip 230 limiting the distance the ball and the grip portion extend from the cavity 222. By turning the adjustment knob 260, the user can modify the positional relationship between the grip portion 240 and the knob 260. Modifying the positional relationship modifies the distance the ball 100 extends from the cavity 222 when the stop surface 266 engages the collar lip 230. Thus, the range of motion of the grip member 240 and ball 100 between the first and second position, as well as the distance the 100 extends from the cavity 222, can be modified. The activation force also can be changed by changing the compressed height of the spring, for example by changing the spring material, or by shimming.
When installed on a walker leg, the glide tip assembly function generally as described in the earlier embodiments above. Specifically, the ball 100 and holder 200 are normally in a first position such that the ball engages the ground 101 with the ground engaging portion 228 of the holder 200 spaced apart from the ground. When sufficient downward force is applied to the walker, the ball 100 retracts, bringing the ground engaging portion 228 into contact with the ground 101.
During the ordinary course of operation of the walker, there is a first amount of friction between the ball 100 and the ground surface 100 and a second amount of friction between the ball and the holder 200. As discussed above regarding the first embodiment, if the first amount of friction is less than the second amount of friction, the ball 100 will slide. If the first amount of friction, however, is greater than the second amount of friction, the ball 100 will roll.
The enclosing portion 310 of the holder 280 is attached to the leg attachment portion 290 by the connecting portion 300. In
The enclosing portion 310 of the holder has a similar configuration to the enclosing portion 80 in the first embodiment (
From the above description of the invention, those skilled in the art will perceive improvements, changes, and modifications in the invention. Such improvements, changes, and modifications within the skill of the art are intended to be included within the scope of the appended claims.
This application claims the benefit of U.S. Provisional Application No. 60/553,701, the entire disclosure of which is hereby incorporated by reference.
Number | Date | Country | |
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60553701 | Mar 2004 | US |