Abstract:
A foldable walker includes upstanding legs arranged in a generally square pattern, each of which is capped by a fixed joint member and each of which has a slider member slideably disposed on it. Two forward legs are interconnected by two rigid links arranged in a scissors arrangement with the uppermost end of each link pivotally connected to a fixed joint member and the lowermost end of each link pivotally connected to a slider. Each forward leg is interconnected to its associated rearward leg in the same way. Each pair of rigid links is interconnected to one another by a pivot pin. The linkage enables the width and the depth of the walker to be reduced to a very small space and telescoping legs reduce the height dimension of the walker. Handles are folded when the walker is stored and pivoted into their operable position when the walker is deployed.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to currently pending U.S. Provisional Patent Application No. 61/227,246, entitled “FOLDABLE WALKER”, filed on Jul. 21, 2009, the contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates, generally, to medical appliances known as walkers. More particularly, it relates to a walker that has a storage configuration that has less height, depth and width than its fully deployed configuration. 
     2. Description of the Prior Art 
     A walker is a three-sided tubular frame device having a transversely disposed front end and a pair of side frames disposed at roughly right angles to opposite ends of the front structure and in trailing relation thereto. The person using the walker stands in a space where the front end is forward of the person and the side frames are to the left and right. The top of each side frame provides a horizontal, longitudinally extending handle for grasping by the user. 
     The front end includes two (2) transversely spaced apart legs and each side structure includes one (1) leg that trails its associated front leg. A total of four (4) legs, roughly arranged in a square pattern, provide a stable structure upon which a person can lean or otherwise use for support when standing or walking. Walking requires that the user lift the walker and move it in the direction of walking after each step or steps. Some walkers include wheels for the front two (2) legs so that the walker can be rolled forwardly after each step. 
     It is a simple matter to add hinges to the opposite ends of the front structure so that the two side frames can be folded toward one another when the walker is not in use. Such folding reduces the depth of the walker but not its height or its width. Such reduction in depth is desirable because it enables a number of folded walkers to be stored in a space occupied by a single unfolded walker. 
     Walkers have also been developed that have telescoping or folding legs so that the height dimension of the walker can also be reduced to further optimize storage space. 
     However, a foldable walker that has a reduced depth, a reduced height, and a reduced width would represent an important advance in the art of foldable walkers. No such walker appears in the prior art. 
     The known foldable walkers cannot fit into small spaces such as airline overhead storage compartments, compact car front seats, and other such limited space environments. 
     Moreover, most of the known foldable walkers are mechanically complex and cause their owners to seek help when deploying them for use or folding them after use. Such dependence on others reduces the user&#39;s sense of independence and thereby is detrimental to the user&#39;s mental well-being. 
     Thus there is a need for a foldable walker that is foldable in all three dimensions so that it can fit into airline overhead compartments, compact car front seats and the like. 
     There is a need as well for a foldable walker that is mechanically simple to fold and unfold so that the user need not seek assistance from third parties when beginning or ending use of the walker. 
     SUMMARY OF THE INVENTION 
     The long-standing but heretofore unfulfilled need for a walker that is foldable in three dimensions to maximize storage space is now met by a new, useful, and non-obvious invention. 
     The novel walker includes first, second, third, and fourth upstanding legs arranged in a generally square pattern. The first and second upstanding legs are disposed in transversely opposed, lateral relation to one another and collectively form a front end of the walker. The first and third upstanding legs are disposed in longitudinally spaced apart relation to one another and collectively form a left side of said walker, and the second and fourth upstanding legs are disposed in longitudinally spaced apart relation to one another and collectively form a right side of the walker. 
     First, second, third, and fourth fixed joint members are respectively disposed in surmounting relation to the first, second, third, and fourth upstanding legs. First, second, third, and fourth slider members are respectively slideably disposed on the first, second, third, and fourth upstanding legs below the fixed joint members. 
     A first rigid link has a first end pivotally connected to the first fixed joint member and a second end pivotally connected to the second slider. A second rigid link has a first end pivotally connected to the second fixed joint member and a second end pivotally connected to the first slider. A third rigid link has a first end pivotally connected to the second fixed joint member and a second end pivotally connected to the first slider. A fourth rigid link has a first end pivotally connected to the first fixed joint member and a second end pivotally connected to the third slider. A fifth rigid link has a first end pivotally connected to the second fixed joint member and a second end pivotally connected to the fourth slider. A sixth rigid link has a first end pivotally connected to the fourth fixed joint member and a second end pivotally connected to the second slider. 
     Each rigid link of the first, second, third, fourth, fifth and sixth rigid links has a circular hub that is centrally apertured. A first pivot pin extends through the respective central apertures of the respective central hubs of the first and second rigid links and thereby pivotally interconnects the first and second rigid links. A second pivot pin extends through the respective central apertures of the respective central hubs of the third and fourth rigid links and thereby pivotally interconnects the third and fourth rigid links. A third pivot pin extends through the respective central apertures of said respective central hubs of the fifth and sixth rigid links, thereby pivotally interconnecting the fifth and sixth rigid links. 
     Displacing the first and second upstanding legs toward one another causes the third and fourth legs to be displaced toward one another and toward the first and second upstanding legs, respectively. Displacing the first and second upstanding legs away from one another causes the third and fourth legs to be displaced away from one another and away from the first and second upstanding legs, respectively. 
     A first handle has a first end pivotally connected to the third fixed joint member and has a stored configuration where it is substantially vertically disposed, parallel to the third upstanding leg and disposed in abutting relation thereto. The first handle has an elongate extent substantially equal to the longitudinal spacing between said first and third fixed joint members and has a fully deployed configuration where it is substantially horizontally disposed. The first handle has a second end that releasably engages the first fixed joint member when fully deployed. 
     A second handle has a first end pivotally connected to the fourth fixed joint member and has a stored configuration where it is substantially vertically disposed, parallel to the fourth upstanding leg and disposed in abutting relation thereto. The second handle has an elongate extent substantially equal to the longitudinal spacing between the second and fourth fixed joint members and has a fully deployed configuration where it is substantially horizontally disposed. The second handle has a second end that releasably engages the second fixed joint member when fully deployed. 
     Each of the upstanding legs has a cylindrical shape and each of the fixed joint members has a downwardly opening blind cylindrical bore formed therein to securely receive an uppermost end of a respective upstanding leg therein. 
     The first and second fixed joint members have a base formed by four flat sides and a square configuration when viewed in plan. Both of the first and second fixed joint members also have a pair of transversely spaced apart lugs formed integrally with their respective bases and the lugs projecting upwardly from their respective bases. 
     The second end of the first handle is flat and is disposed between the pair of transversely spaced apart lugs formed integrally with the first fixed joint member when the first handle is fully deployed and the second end of the second handle is flat and is disposed between the pair of transversely spaced apart lugs formed integrally with the second fixed joint member when the second handle is fully deployed. 
     The third and fourth fixed joint members also have a base formed by four flat sides and a square configuration when viewed in plan. Both of the third and fourth fixed joint members have a pair of transversely spaced apart lugs formed integrally with their respective bases and the lugs extend longitudinally in trailing relation to their respective bases. 
     The first end of the first handle is flat and is disposed between the pair of transversely spaced apart, longitudinally extending lugs. It is permanently pivotally connected to said pair of transversely spaced apart, transversely extending lugs. The first end of the second handle is also flat and is permanently disposed between the pair of transversely spaced apart, longitudinally extending lugs formed integrally with the second fixed joint member when the second handle is fully deployed. 
     The primary object of this invention is to provide a walker that can be folded into a very small space. 
     A closely related object is to provide a walker that can be reduced in height, depth, and width. 
     Another object is to accomplish the foregoing object in a mechanically elegant way so that a walker user need not seek third party assistance when deploying or folding the walker. 
     These and other important objects, advantages, and features of the invention will become clear as this description proceeds. 
     The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which: 
         FIG. 1  is a front perspective view of the novel walker in a partially deployed and partially folded configuration; 
         FIG. 2  is a rear perspective view of the walker when opened to its full width and depth but not its full height; 
         FIG. 3  is a front perspective view when the walker is fully deployed; 
         FIG. 4  is a rear perspective view of the walker when fully folded; 
         FIG. 5  is a top plan view of the walker when fully folded; 
         FIG. 6  is a rear elevational view of the walker when fully folded; 
         FIG. 7  is a right side elevational view of the walker when fully folded; and 
         FIG. 8  is a front elevational view of the walker when fully folded. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIG. 1 , it will there be seen that the novel walker is denoted as a whole by the reference numeral  10 . In  FIG. 1 , the telescoping legs are fully retracted so walker  10  is in its shortest configuration. However, walker  10  is depicted in a partially but not quite fully open configuration both in the width and depth dimensions. 
     Novel walker  10  includes four upstanding cylindrical legs denoted  12 ,  14 ,  16 , and  18 . Each is respectively capped at its bottom by conventional protective covers  12   a ,  14   a ,  16   a , and  18   a  that form no part of the invention per se. Conventional rollers could also be provided in a well-known way. 
     Forward legs  12  and  14  are transversely opposed to one another when the walker is fully deployed and oriented in a forward direction of travel, i.e., said legs are in lateral relation to one another when the walker is so deployed and oriented. Legs  12  and  14  collectively form the front end of the walker. Rearward legs  16  and  18  are also transversely opposed to one another when the walker is fully deployed and oriented in a forward direction of travel, i.e., said rearward legs are in lateral relation to one another when the walker is so deployed and oriented. Legs  12  and  16  are longitudinally spaced apart from one another and collectively form the left side of the walker. Legs  14  and  18  are longitudinally spaced apart from one another and collectively form the right side thereof. 
     First fixed joint member  20  surmounts first leg  12 . It has a downwardly opening blind cylindrical bore formed therein to slidingly and securely receive the uppermost end of leg  12  therewithin. Fixed joint member  20  has a base formed by four flat sides and therefore has a generally square configuration when seen in plan view. It includes a pair of transversely opposed lugs, collectively denoted  20   a , that project upwardly from the base, each of which is centrally apertured as depicted. 
     Opposite ends of a connecting pin are disposed within the apertures. The connecting pin is spring-loaded so that it may be released by squeezing its opposite ends toward one another, i.e., such squeezing causes retraction of the opposite ends from the apertures so that an item held by such pin is released and can be removed from the space between said lugs. The opposite ends of the pin are rounded so that said pins momentarily retract when an item to be locked into the space between the lugs is inserted into the space. The self-bias then causes the opposite ends of the pin to extend into the apertures to lock the item into place until the opposite ends of the pin are manually squeezed as aforesaid. 
     Second fixed joint member  22  surmounts second leg  14 . It has a downwardly opening blind cylindrical bore formed therein to slidingly receive the uppermost end of leg  14  therewithin. Fixed joint member  22  has a base having four flat sides and therefore has a generally square configuration when seen in plan view. It includes a pair of transversely opposed lugs, collectively denoted  22   a , that project upwardly from said base. Each lug is centrally apertured as depicted so that a spring-loaded connecting pin, mentioned above, may be extended therebetween. 
     First and second fixed joint members  20  and  22  have a common length as depicted. 
     Third fixed joint member  24  surmounts third leg  16 . It has a downwardly opening blind cylindrical bore formed therein to slidingly receive the uppermost end of leg  16  therewithin. Fixed joint member  24  has a base including four flat sides. It includes a pair of transversely opposed, longitudinally-extending lugs, collectively denoted  24   a , that extend in trailing relation from said four-sided base. Each lug is centrally apertured near its trailing end as depicted to receive opposite ends of solid connecting pin  24   b , said opposite ends being press fit into their respective openings so that pin  24   b  is permanently installed as depicted in  FIG. 1 . The opposite ends of pin  24   b  are flat and flush with the respective outer surfaces of lugs  24   a . Handle  48 , disclosed hereinafter, is pivotally connected to pin  24   b  and is free to rotate about said pin as disclosed hereinafter in connection with said handle  48 . Fixed joint member  24  has the appearance of an inverted “L” when viewed in side elevation. 
     Fourth fixed joint member  26  surmounts fourth leg  18 . It has a downwardly opening blind cylindrical bore formed therein to slidingly receive the uppermost end of leg  18  therewithin. Fixed joint member  26  has a base including four flat sides. It further includes a pair of transversely opposed, longitudinally-extending lugs, collectively denoted  26   a , each of which is centrally apertured near its trailing end as depicted to receive opposite ends of solid connecting pin  26   b , said opposite ends being press fit into their respective openings so that pin  26   b  is permanently installed as depicted in  FIG. 1 . The opposite ends of pin  26   b  are flat and flush with the respective outer surfaces of lugs  26   a . Handle  50 , disclosed hereinafter, is pivotally connected to pin  26   b  and is free to rotate about said pin as disclosed hereinafter in connection with said handle  50 . Fixed joint member  26  has the appearance of an inverted “L” when viewed in side elevation. 
     Third and fourth fixed joint members  24  and  26  have a common length as depicted. The common length of fixed joint members  24 ,  26  exceeds the common length of fixed joint members  20 ,  22 . 
     First slider  28  slideably engages first leg  12  and has four flat sides sharing a common size and said slider has a square configuration when viewed in plan. A central bore is formed therein for sliding reception of first leg  12 . Second, third, and fourth sliders  30 ,  32 , and  34  have the same structure and are respectively slidingly received on second, third, and fourth legs  14 ,  16 , and  18 , respectively. 
     First rigid link  36  has a first end pivotally connected to first fixed joint member  20  at pivot point  36   a  and has a second end pivotally connected to second slider  30  at pivot point  36   b . Rigid link  36  has a circular central hub  36   c  that is centrally apertured to receive pivot pin  37 . 
     Second rigid link  38  has a first end pivotally connected to second fixed joint member  22  at pivot point  38   a  and has a second end pivotally connected to first slider  28  at pivot point  38   b . Second rigid link  38  has a circular central hub  38   c  that is centrally apertured to receive pivot pin  37 . 
     Circular central hub  36   c  of link  36  underlies circular central hub  38   c  in  FIG. 1  as indicated by the dotted lead line associated with said circular central hub  36   c . Pivot pin  37  is common to links  36 ,  38  and said links rotate about said pivot pin in a scissors-like action as legs  12  and  14  are brought closer to one another when walker  10  is being folded from a deployed configuration and said links rotate about said pivot pin as legs  12  and  14  are separated from one another when walker  10  is being deployed from a folded configuration. Sliders  28  and  30  slide downwardly relative to their respective legs during a folding action and they slide upwardly when walker  10  is being deployed for use. 
     Third rigid link  40  has a first end pivotally connected as at  40   a  to a flat outer side wall of first fixed joint member  20  and has a second end pivotally connected as at  40   b  to a flat outer sidewall of third slider  32 . Third rigid link  40  has a circular central hub  40   c  that is centrally apertured to receive a pivot pin like pivot pin  37  but the central hub and pivot pin are not numbered in  FIG. 1  to avoid cluttering the drawing. The respective pivot points  40   a  and  40   b  and central hub  40   c  are obscured in  FIG. 1  but share the same structure as pivot points  36   a ,  36   b  and central hub  36   c.    
     Fourth rigid link  42  has a first end pivotally connected as at  42   a  to a flat outer sidewall of third fixed joint member  24  and has a second end pivotally connected as at  42   b  to a flat outer sidewall of first slider  28 . Fourth rigid link  42  has a circular central hub  42   c  that is centrally apertured to receive a pivot pin like pivot pin  37 . The respective pivot points  42   a  and  42   b  and central hub  42   c  are not numbered in  FIG. 1  to avoid cluttering the drawing. 
     The circular central hub of link  42  underlies the circular central hub of link  40  as depicted in  FIG. 1 . A pivot pin  41  like pivot pin  37  is common to links  40  and  42  and said links rotate about said pivot pin as legs  12  and  16  are brought closer to one another when walker  10  is being folded from a deployed configuration and said links rotate about said pivot pin as legs  12  and  16  are separated from one another when walker  10  is being deployed from a folded configuration. Sliders  28  and  32  slide downwardly relative to their respective legs during a folding action and they slide upwardly when walker  10  is being deployed for use. 
     Fifth rigid link  44  has a first end pivotally mounted as at  44   a  to a flat outer side wall of second fixed joint member  22  and has a second end pivotally connected to a flat outer sidewall of fourth slider  34  as at  44   b . Fifth rigid link  44  has a circular central hub  44   c  having a dotted lead line because it is obscured in  FIG. 1 . Central hub  44   c  is centrally apertured to receive pivot pin  45 . 
     Sixth rigid link  46  has a first end pivotally mounted to a flat outer sidewall of fourth fixed joint member  26  as at  46   a  and has a second end pivotally connected as at  46   b  to a flat outer sidewall of second slider  30 . Sixth rigid link  46  has circular central hub  46   c  that is centrally apertured to receive pivot pin  45 . 
     The circular central hub  44   c  of link  44  underlies circular central hub  46   c  of link  46  as depicted in  FIG. 1 . Pivot pin  45  is common to links  44  and  46  and said links rotate about said pivot pin as legs  14  and  18  are brought closer to one another when walker  10  is being folded from a deployed configuration and said links rotate about said pivot pin as legs  14  and  18  are separated from one another when walker  10  is being deployed from a folded configuration. Sliders  30  and  34  slide downwardly relative to their respective legs during a folding action and they slide upwardly when walker  10  is being deployed for use. 
     Handles  48  and  50  are depicted in their folded, undeployed configuration in  FIG. 1 . When so folded, they lie parallel to legs  16  and  18 , respectively, in abutting relation thereto. 
     A first end of handle  48  is flat and pivotally connected to fixed joint member  24  between longitudinally-extending lugs  24   a ,  24   a  by permanent pivot pin  24   b  disclosed in detail above so that a second flat end of said handle can be releasably inserted between lugs  20   a ,  20   a  of fixed joint member  20 . When so inserted, spring-loaded pin  20   b  releasably secures said second flat end between said lugs. Spring-loaded pin  20   b  has rounded opposite ends that protrude from the respective outer surfaces of lugs  20   a ,  20   a  so that a user may compress said pin to release handle  48  when said handle is to be returned to its storage configuration. 
     A first end of handle  50  is flat and pivotally connected to fixed joint member  26  between lugs  26   a ,  26   a  by permanent pivot pin  26   b  disclosed in detail above so that a second flat end of said handle can be inserted between lugs  22   a ,  22   a  of fixed joint member  22 . When so inserted, spring-loaded pin  22   b  releasably secures said second flat end between said lugs. Spring-loaded pin  22   b  has rounded opposite ends that protrude from the respective outer surfaces of lugs  22   a ,  22   a  so that a user may compress said pin to release handle  50  when said handle is to be returned to its storage configuration. 
       FIG. 2  depicts handles  48  and  50  when operatively deployed. Walker  10  is therefore at its maximum depth. It is also locked into its maximum width but it is not at its maximum height because the telescoping legs are retracted. 
       FIG. 3  depicts the legs in their respective fully extended configurations and the walker is thus in its fully deployed configuration. Of course, the amount of leg extension depends upon the height of the user. Tubes  12   b ,  14   b ,  16   b , and  18   b  are slideably received within the hollow interiors of legs  12 ,  14 ,  16 , and  18  in a well-known way and said tubes are provided with equidistantly spaced apart apertures  12   c ,  14   c ,  16   c , and  18   c  along their respective extents to accommodate spring-loaded locking pins  12   d ,  14   d ,  16   d , and  18   d  having rounded opposite ends that protrude so that the height of walker  10  can be adjusted by momentarily compressing said locking pins in a well-known way. 
     Now that walker  10  has been depicted in partially and fully deployed configurations, the various views that depict it in its fully folded configuration will be more easily understood.  FIG. 4  is a rear perspective view of the fully folded walker and  FIG. 5  is a top plan view thereof.  FIGS. 6 ,  7 , and  8  are rear elevational, right side elevational, and front elevational views respectively. The various pivot points obscured in  FIGS. 1-3  are not obscured in  FIGS. 4-8 . 
     It should also be understood that the four (4) legs are parallel to one another when the walker is totally folded, but they are oblique to one another when the walker is deployed, i.e., the legs are slightly further apart at their lowermost ends relative to their uppermost ends as is clear from the drawings. This stabilizes the walker in the two (2) directions of front-rear and left-right. 
     Deploying the novel walker from its fully folded configuration merely requires grasping any two of the legs and pulling them apart from one another. The elegant scissors-like linkage ties all of the legs together so that when two contiguous legs are pulled apart, all four of them diverge from one another. Handles  48  and  50  are easily rotated into position to lock the walker frame into a stable, safe configuration, there being no need to squeeze any connecting pins to accomplish said deployment of the handles. The legs are then extended to the desired length, again in the absence of any need to squeeze any pins. A pin associated with each leg and handle is squeezed to release those items when the walker is returned to its folded configuration. When the handles are pivoted back to their respective storage configurations, pushing any two contiguous legs toward one another will return all four legs to their storage configuration. When all four legs are totally closed, pins  12   d ,  14   d ,  16   d , and  18   d  are pressed momentarily to allow retraction of the extended legs as aforesaid. 
     It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.