Abstract:
A collapsible side wheeled walker accommodates a user walking to one side of the walker while holding the walker and supporting at least a portion of the user&#39;s weight on the walker. The walker can be collapsed in a tripod-like manner into a compact configuration that is easily transported and stowed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority to Provisional Application Ser. No. 60/383,621, filed May 29, 2002, the disclosure of which is incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to walkers, and in particular, to collapsible walkers with wheels. 
   2. Description of the Related Art 
   Wheeled walkers may be used as a walking aid by people who are temporarily or permanently disabled and who may have difficulty walking unaided. Some walkers roll on three or four sets of wheels. Some walkers have handles that are grasped by the user. The user holds the handles for support and pushes the walker forward as the user walks. These walkers are often pushed in front of the user, and thus provide generally symmetric support. 
   Some people, however, have asymmetric disabilities. Asymmetric disabilities are those disabilities that affect one side of a person&#39;s body more than the other side. Polio or post-polio syndrome, for example, can produce muscular weaknesses or structural deformities on one side of a person&#39;s body. Some stroke or accident victims may be affected similarly. Asymmetric disabilities thus create a need for support on one side of a person&#39;s body. 
   A cane is an example of a support on one side of a person&#39;s body. A cane is placed on the ground to support a person between steps. A cane, therefore, provides cyclical support synchronized with a person&#39;s gait. There are people, however, who need a constant, steady support. The intermittent support offered by a cane may not be an acceptable solution for many of these people. 
   Walkers often have to be picked up and carried during use. Walkers may need to be picked up, for example, when climbing stairs, entering vehicles, crossing barriers, or traversing narrow doorways. Walkers also need to be stored in compartments such as closets, overhead bins on airplanes and buses, automobile trunks, and under seats in theaters or restaurants. It would be desirable therefore for a walker to collapse down to the smallest possible size for case of transport and storage. 
   SUMMARY OF THE INVENTION 
   The foregoing, and other, shortcomings of conventional walkers are overcome by a collapsible side-wheeled walking aid for assisting a user walking to one side of said aid. The walking aid is selectively configurable in either a functional or a stowable state and includes a frame having three frame members interconnected with one another proximate upper ends thereof. At least two of the frame members are interconnect so as to be moveable between first and second positions. In the first positions, when the aid is in the functional state, the frame members extend away from each other toward lower ends thereof so that the frame is in a stable, weight supporting configuration. In the second positions, when the aid is in the stowable state, the lower ends of the frame members are in close proximity to each other so that the frame is in a compact configuration. A wheel assembly is disposed on a lower end of at least one of the frame members. A handle is disposed on an upper end of the frame. The handle is constructed and arranged in relation to the frame to permit a user to grasp the handle with one hand and to walk while supporting at least a portion of the user&#39;s weight on the aid while rolling the frame on the wheel assembly with the aid positioned to one side of the user. 
   In one embodiment, the walker includes a frame generally having the shape of a triangular pyramid and including a main leg, a rear, and a side leg. The main, rear, and side legs are interconnected proximate a vertex of the pyramid. At least two of the legs are connected within the frame so as to be pivotable with respect to the third leg when the frame is collapsed. 

   
     DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a perspective view of an embodiment of the collapsible side wheeled walker of the present invention in use; 
       FIG. 2  is a rear view of the embodiment of the collapsible side wheeled walker shown in  FIG. 1  in use; 
       FIG. 3  is a side view of the embodiment of the collapsible side wheeled walker shown in  FIG. 1 ; 
       FIG. 4  is a view of the embodiment of the collapsible side wheeled walker shown in  FIG. 1  in a collapsed configuration; 
       FIGS. 5A-5C  are partial views of a foldable strut in accordance with one aspect of the invention; and 
       FIG. 6  is a partial view of a wheel and brake mechanism of an embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A collapsible walking aid (or walker) is shown in  FIGS. 1 through 4 . Aid  10  is adapted to be selectively reconfigured in either the functional state shown in  FIGS. 1-3  or the stowable state shown in FIG.  4 . Walking aid  10  includes a frame  20 . Frame  20  includes three leg members  102 ,  112 ,  120  interconnected proximate their respective upper ends  106 ,  114 ,  122 . The leg members  102 ,  112 ,  120  are interconnected so as to be movable between first positions extending away from each other toward their respective lower ends  110 ,  118 ,  126  so that frame  20  is in a stable, weight-supporting configuration, as shown in  FIGS. 1-3 , when the aid  10  is in its functional state and second positions in which the lower ends  110 ,  118 ,  126  of the frame members are in close proximity with each other, as shown in  FIG. 4 , when the aid  10  is in the stowable state. In the context of the present disclosure, “close proximity” means that the lower ends of adjacent frame members are physically separated by a distance that is significantly smaller than the physical distance separating the lower ends when not in close proximity to each other, i.e., when the walking aid  10  is in the functional state. Close proximity may or may not mean that the lower ends of adjacent frame members contact each other. 
   In the illustrated embodiment, collapsible walking aid  10  includes a main leg (or frame member)  102  having a main upper end  106  and a main wheel assembly  108  at a main lower end  110 . Main wheel assembly  108  may be a single wheel as shown, or a set of wheels. Wheel assembly  108  is castered in the illustrated embodiment. Main leg  102  is preferably formed of a light weight, tubular material, such as extruded aluminum, or one of the many strong light-weight man-made materials, such as carbon-based composite materials. 
   A rear leg (or frame member)  112  having a rear upper end  114  is fastened pivotably to main upper end  106  of main leg  102  using a fastener  182 . Rear leg  112  is preferably formed of a light weight tubular material, such as extruded aluminum, or one of the many strong light-weight man-made materials, such as carbon-based composites. Fastener  182  comprises a bracket  183  firmly secured to the upper end  106  of main leg  102 . Bracket  183  may be secured to main leg  102  by mechanical fasteners (e.g., screws, bolts, rivets), by welding (if both bracket  183  and leg  102  are made of metal), by a suitable adhesive, or by any means for securely fastening bracket  183  to main leg  102 . The upper end  114  of rear leg  112  is secured to bracket  183  by a pin  185  (for example a metal pin, a bolt, an axle, etc.) which allows rear leg  112  to pivot with respect to main leg  102 . Rear leg  112  may have a rear wheel assembly  116  at a rear lower end  118 . Rear wheel assembly  116  may be castered and may be a single wheel or a set of wheels. 
   A side leg (or frame member)  120  having a side upper end  122  is fastened pivotably to rear upper end  114  of rear leg  112  using a fastener  184 . Side leg  120  is preferably formed of a light-weight tubular material, such as extruded aluminum, or one of the many strong man-made materials, such as carbon-based composites. Fastener  184  comprises a bracket  187  firmly secured to the upper end  114  of rear leg  112 . Bracket  187  may be secured to the rear leg  112  by mechanical fasteners (e.g., screws, bolts, rivets), by welding (if both bracket  187  and leg  112  are made of metal), by a suitable adhesive, or by any means for securely fastening bracket  187  to leg  112 . The upper end  122  of side leg  120  is secured to bracket  187  by a pin  189  (for example, a metal pin, a bolt, an axle, etc.) which allows side leg  120  to pivot with respect to rear leg  112 . Side leg  120  is canted outwardly from main leg  102  and rear leg  112  when collapsible walker  10  is in its functional state to provide lateral support. 
   Side leg  120  may have a side wheel assembly  124  at a side lower end  126 . Side wheel assembly  124  may include a single wheel or a set of wheels, and side wheel assembly  124  may be castered. It is preferable that only one or two of the legs  102 ,  112 ,  120  include a castered wheel assembly. As an alternative to the arrangement shown, side leg  120  may be pivotally attached toward an upper end  106  of main leg  102 . In an alternate embodiment, the wheel assembly may be omitted from the side leg  120  and replaced by a ground engaging foot or pad attached to the lower end of leg  120 . 
   Main, rear and side legs  102 ,  112 ,  120  thus form an interconnected frame  20 , with side leg  120  connected to rear leg  112 , and rear leg  112  connected in turn to main leg  102  to form a frame having the general shape of a triangular pyramid when the walking aid  10  is its functional state. Main, rear and side legs  102 ,  112 ,  120  are thus interconnected at or near the vertex of the pyramidal frame  20 , and at least two of the legs (the rear leg  112  and side leg  120  in the illustrated embodiment) are pivotable with respect to the third leg (e.g. main leg  102 ) so that, when the frame  20  is collapsed, collapsible walking aid  10  occupies the smallest possible amount of space. 
   More specifically, as shown in the example embodiment illustrated in  FIG. 4 , main, rear and side legs  102 ,  112 ,  120  can be folded adjacent to each other in a tripod-like manner when the walker  10  is in its stowable state, making a compact package that may be easily transported or stored. Collapsible walking aid  10  may be stored easily in the baggage lockers and overhead bins above airline seats or under a seat in a theater or restaurant. 
   An asymmetric disability may affect either the left or the right side of a person. It would be desirable therefore for a user to be able to use the walker as either a left-handed walker or a right-handed walker. It would be further desirable for the walker to be easily convertible from a left-handed walker to a right handed walker, and vice-versa. 
   Side leg  120  may be oriented to extend to the right of main leg  102  for right-handed users or to the left of main leg  102  for left-handed users. In this embodiment, collapsible walker  10  may be used in a left handed orientation and a right handed orientation. Thus, in an alternate embodiment, bracket  187  of fastener  184  is removably fastened (e.g., by bolts or screws) to rear leg  112  so that the bracket  187  can be oriented and fastened to leg  102  pointing to the left or the right hand side of frame  20 . 
   A handle  144  is positioned proximate an upper end of frame  20 . Handle  144  includes a generally horizontally—oriented grasping portion  143  and a lower portion  145  arranged at an angle (obtuse in the illustrated example) with respect to grasping portion  143 . Handle  144  is also made from a strong, light-weight tubular material, such as extruded aluminum or a man-made material such as a carbon-based composite. Portion  145  fits telescopically with respect to the upper portion  106  of the main leg  102 . Handle  144  is preferably secured by a pin  150  extending into leg  102  and into one of a plurality of aligned, longitudinally-spaced apertures (not shown) formed in the lower portion  145  when one of the apertures of the lower portion is aligned with pin  150 . In the illustrated example, pin  150  is a threaded rod with a head at one end and a star-shaped, manually operable threaded nob  151  at an opposite end. In one embodiment shown in  FIGS. 1 and 2 , pin  150 , (e.g., a bolt and nut combination) also secures a utility hook  152  to the frame  20 . Accordingly, the height of the gripping portion  143  may be adjusted by sliding the lower portion  145  relative to leg  102  and inserting the pin  150  into one of the apertures formed in lower portion  145  so as to secure the handle  144  with the gripping portion  143  at the desired height. 
   A first foldable strut  128  is fastened pivotably to main leg  102  at a first end  130  and to rear leg  112  at a second end  132 . First foldable strut  128  has a first hinge  134  disposed substantially intermediate between first end  130  and second end  132 . First foldable strut  128 , main leg  102  and rear leg  112  form a frame in the shape of a triangle when collapsible walker  10  is set up for use in the functional state. 
   A second foldable strut  135  is fastened pivotably to side leg  120  at a first end  136  and to rear leg  112  at a second end  138 . Second foldable strut  135  includes a second hinge  140  disposed substantially intermediate between first end  136  and second end  138 . Second foldable strut  135 , side leg  120  and rear leg  112  form a frame in the shape of a triangle when collapsible walker  10  is set up for use in the functional state. If side leg  120  is pivotally connected to main leg  102 , strut  135  would preferably be pivotally connected at its ends  138 ,  136  to main leg  102  and side leg  120 . 
   First and second hinges  134 ,  140  are lockable when collapsible walker  10  is in the functional state and are releasable when collapsible walker  10  is collapsed in the stowable state. More specifically, first and second hinges  134 ,  140  are locking, over-center hinges. Suitable alternative locking hinges include clasp hinges and sliding bar hinges. 
   In a conventional manner, illustrated in  FIGS. 5A-5C , over-center locking hinge  134  ( 140 ) permits halves  176  and  178  of first strut  128  to pivot in one direction about their anchor points  130  and  132 , connected to main leg  102  and rear leg  112 , respectively, to permit main leg  102  and rear leg  112  to collapse with respect to each other. To lock the strut  128  in the extended position, halves  176 ,  178  are moved past an aligned arrangement to an over-center position, shown in  FIGS. 5B and 5C , into a position where further rotation of the halves  176 ,  178  is arrested by contact with stop  180 . 
   To collapse the collapsible walker, the locking action is overcome by applying an upward force on the middle of the strut  135  to relieve the over-center condition. Second hinge  140  may be designed similarly. 
   In the example shown, the walker  10  includes a braking mechanism for selectively arresting rolling progress of the walker. More specifically, as shown in  FIGS. 1-3  and  7 , a brake  142  is disposed proximate to rear wheel assembly  116 . A lever  147  is pivotably connected to handle  104 . A tension member  146  is connected at a first end to lever  147  and at a second end to brake  142 . 
   In the embodiment shown in  FIG. 6 , brake  142  includes an L-shaped member  145  pivotally connected to rear leg  112 . Upon activation of the lever  147 , tension member  146  transmits a pivoting force to member  145  causing a lower end thereof into braking engagement with wheel  116 . Spring  149  causes the member  145  to disengage when the handle  147  is released. Tension member  146  urges rear brake  142  into braking engagement with rear wheel  116  when lever  147  is pivotably actuated. Tension member  146  may be a cable, a wire, a rope, or a chain in various embodiments. As is conventional in such manually actuated braking mechanisms, one or more resilient members (e.g., springs) are operatively arranged to relieve the braking engagement when lever  147  is released. Moreover, a locking mechanism (not shown) may be provided (preferably on or near handle  147 ) for selectively locking the handle in the braking actuated position when released to provide a “parking brake” functionality. 
   Braking mechanisms may also be provided on main wheel assembly  108  and/or side wheel assembly  124 , and the multiple braking mechanisms may operate independently or in conjunction with each other. Alternative braking mechanisms include bicycle-style caliper brakes. 
   In use, collapsible walker  10  may be held to the side of a user (as shown in FIG.  2 ), supporting the user while the user walks forward at a rate of speed of the users choosing. The user grasps the gripping portion  143  of the handle  144  on the top of main leg  102 , which is supported by side leg  120  having side wheel assembly  124  and rear leg  112  having rear wheel assembly  116 . While walking, with wheel assemblies  108 ,  116 , and  124  rolling on the ground, the user can support some portion of his or her weight on the walker  10  to help the user maintain his or her balance. Similarly, the user may use the walker as a balance aid when standing still. If the wheel assembly  124  is omitted from side leg  120 , the user tips the walker slightly inwardly to lift the lower end of side leg  120  off the ground and thereafter walks supporting some portion of his or weight on the main leg  108  and rear leg  112 . 
   While the invention has been described in detail above, the invention is not intended to be limited to the specific embodiments as described. It is evident that those skilled in the art may now make numerous uses and modifications of and departures from the specific embodiments described herein without departing from the inventive concepts.