Abstract:
A knee walker for use as a walking aid by disabled persons includes multiple wheels operably coupled to a frame and a steering assembly. A knee pad is supported by the frame intermediate front and rear wheels to support a user&#39;s bent knee and lower leg thereon. A suspension or shock absorbing assembly is disposed intermediate the knee rest pad and the frame. The knee walker is adjustable to accommodate users of varying sizes.

Description:
RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Application Ser. No. 62/267,408, filed Dec. 15, 2016. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to the field of ambulatory assistive devices for the physically impaired. More particularly, the present invention relates to a knee mobility walker for aiding the disabled in walking. 
         [0003]    In situations where an individual has injured, or had a surgical procedure on, a lower portion of the leg, ankle or foot, it is preferred medically to keep weight off of the lower leg or foot while recuperating. Traditionally, this has been achieved by the use of wheelchairs or crutches. 
         [0004]    A wheelchair is generally prescribed for patients who do not have the balance, strength or stability to use crutches or a walker. However, medical studies have demonstrated that a wheelchair can contribute to a deterioration of cardiovascular health, strength and overall energy. Doctors and patients alike recognize that the earlier a patient is able to be mobile and stay out of a wheelchair, the more progress a patient makes toward his or her recovery. Moreover, wheelchairs can be undesirable for reasons such as transporting the wheelchair and limited access during use. 
         [0005]    Traditionally, doctors have recommended crutches when a patient is required to keep their bearing weight off of a foot or leg. Unfortunately, crutches exhibit a number of requirements and restrictions, including requiring the patient to maintain their balance, hold up the weight of the injured leg, and require the patient to constantly shift their weight back and forth to move forward. Crutches can be difficult to maneuver on uneven or loose ground. Sore or bruised body tissue, sprained and sore wrists and a propensity for falling also typically go hand-in-hand with the use of crutches. Moreover, anyone with a history of shoulder injury or surgery, breast cancer, wrist injury or surgery, or certain other conditions, may be restricted from the use of crutches. 
         [0006]    Knee walkers, also referred to as knee scooters or knee rollers, have become increasingly popular in recent years as canes, crutches and the like have been found inconvenient and unstable for certain persons with leg, foot and ankle injuries or ailments. Such knee walkers typically provide more stability and mobility than crutches, a walker or a wheelchair. The knee walker will generally have wheels attached to a frame and a pad supported by the frame intermediate the front and back wheels so as to allow the user to rest his or her injured leg on the pad and use his or her non-injured leg to propel the device across a surface. The knee walker&#39;s wheels and user&#39;s ability to maintain one leg on the ground during use adds to the stability and mobility of the knee walker. Such knee walkers have been advantageous to assist in easier and safer mobility and for traveling longer distances. 
         [0007]    While the benefits of knee walkers are a significant improvement over crutches, walkers and wheelchairs, prior art knee walkers have several shortcomings and drawbacks. Bumps and the like caused by uneven surfaces transmit forces up through the frame and into the user&#39;s knee which is rested on the knee pad. This can cause discomfort and even pain over time. Moreover, while the patients using such knee walkers vary significantly in size, prior art knee walkers are limited in their adjustability to accommodate the sizes of such users. 
         [0008]    Accordingly, there is a continuing need for an improved knee walker which provides suspension between the frame and knee resting pad of the walker and which is easily adjustable to accommodate patients of varying size. The present invention fulfills these needs, and provides other related advantages. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention resides in a knee walker for use as a walking aid by disabled persons. The knee walker generally comprises a frame having at least three wheels comprising front and rear wheels operably coupled to the frame. A steering assembly is operably coupled to at least one of the wheels. The steering assembly comprises a handlebar rotatably disposed within a steering tube of the frame. The at least three wheels may comprise two wheels operably coupled to the steering assembly and a front portion of the frame. A single rear wheel may be coupled to a rear portion of the frame. The frame may be offset such that the rear wheel is generally aligned with the steering tube of the frame. 
         [0010]    The knee pad is supported by the frame intermediate the front and rear wheels. The knee pad is configured to support a user&#39;s bent knee and lower leg thereon. Typically, the user utilizes his or her other leg and foot to propel the knee walker. The knee pad includes an elongated depression formed in a top portion thereof. The depression is configured to receive a knee and at least a portion of a lower leg of the user. 
         [0011]    A suspension assembly is disposed intermediate the knee rest pad and the frame. The suspension assembly in a particularly preferred embodiment comprises a telescopic mechanism having a damper between the knee rest pad and the frame. The suspension assembly may comprise a suspension seat post. The suspension seat post may comprise a hydraulic piston or a pneumatic piston. 
         [0012]    The knee walker typically also includes a hand brake assembly for controllably stopping the knee walker. The hand brake assembly includes a brake cable which extends to a brake caliper of a disc brake. Preferably, the brake cable extends through at least a portion of the frame. 
         [0013]    The knee walker also preferably includes an adjustment mechanism for selectively adjusting the distance between the knee pad and the frame. 
         [0014]    The frame of the knee walker may also include a foot rest platform between the front wheels. The platform is disposed at an angle of approximately ten degrees to thirty degrees towards the user. This enables the user to comfortably rest his or her foot on the foot rest platform when seated on the knee pad, such as when stopped and resting or the like. 
         [0015]    Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The accompanying drawings illustrate the invention. In such drawings: 
           [0017]      FIG. 1  is a side perspective view of a medical knee walker embodying the present invention; 
           [0018]      FIG. 2  is a side perspective view of the knee walker of  FIG. 1 , but in a folded and compact state; 
           [0019]      FIG. 3  is a side view of the knee walker of the present invention illustrating a user operating the knee walker, in accordance with the present invention; 
           [0020]      FIG. 4  is an enlarged perspective view of area “4” of  FIG. 1 , illustrating a brake cable entering a frame of the knee walker, in accordance with the present invention; 
           [0021]      FIG. 5  is an enlarged perspective view of area “5” of  FIG. 1 , illustrating the brake cable exiting from the frame to a brake caliper, in accordance with the present invention; 
           [0022]      FIG. 6  is a cross-sectional view of a knee pad of the knee walker; 
           [0023]      FIG. 7  is a bottom perspective view of the knee pad and a height adjustment mechanism of the knee walker; 
           [0024]      FIG. 8  is a partially sectioned perspective view, illustrating a suspension assembly disposed intermediate the knee rest pad and frame of the knee walker, in accordance with the present invention; and 
           [0025]      FIG. 9  is a rear elevational and diagrammatic view of the knee walker, illustrating the offset frame and alignment of a rear wheel with a steering tube of the frame, in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    As shown in the accompanying photographs and drawings, for purposes of illustration, the present invention is directed to an improved medical knee walker, referred to generally by the reference number  10 . As will be more fully described herein, the knee walker  10  of the present invention overcomes problems and drawbacks of prior medical knee walkers, including providing increased height adjustability and knee pad suspension. 
         [0027]    With reference now to  FIG. 1 , a knee walker  10  embodying the present invention is shown. The knee walker  10  of the present invention is specifically designed as a medical device for those who have a lower leg, ankle or foot injury, have had surgery on these areas of the body, or for amputees of these body parts or have other ailments affecting these body parts. 
         [0028]    The knee walker  10  includes a frame  12 . As illustrated in the various figures herein, the frame  12  may be comprised of generally tubular or hollow members which are operably joined to one another, such as by welding, or the frame may be created by molding techniques or the like. As illustrated, the frame  12  includes an upper frame member  14  and a lower frame member  16 . 
         [0029]    The knee walker  10  includes a plurality of wheels to support the frame  12  and provide mobility to the knee walker  10 . Typically, as illustrated, there are at least three wheels, although the invention contemplates utilizing four wheels. Utilizing three or four wheels provides stability to the knee walker  10  which is important for those utilizing the knee walker  10  who have a medical condition and need the knee walker  10  for support and mobility. The wheels may be inflated with air, enabling rubber to be utilized for the tires and provide sufficient grip and also providing a degree of dampening due to uneven surfaces across which the knee walker  10  is passed. 
         [0030]    In a particularly preferred embodiment, as illustrated, the upper and lower frame members  14  and  16  are joined to one another or otherwise adjacent thereto at one end where a rear wheel  18  is attached to the frame  12 . Opposite ends of the upper and lower frame members  14  and  16  diverge from one another due to bends within the frame members  14  and  16  so as to connect to a generally vertical steering tube  20  of the frame. A lower end of the steering tube  20  and an end of the lower frame member  16  are coupled to an axle cross member  22  which extends in a generally horizontal plane. 
         [0031]    A steering assembly  24  includes a handlebar  26  rotatably disposed within the steering tube  20  of the frame  12 . The handlebar  26  typically has hand grips  28  at ends thereof which can be easily and comfortably gripped by the user of the knee walker  10 . Pushing or pulling the hand grips  28  causes the handlebar  26  to rotate within the steering tube  20  of the frame  12  and pivot and change the angle of front wheels  30  and  32  which are operably coupled to the steering assembly  24 . The front wheels  30  and  32  are typically coupled to generally opposite ends of the crossbar  22  and operably connected to the steering mechanism  24 , such as by tie bars, linkages or the like which interconnect the handlebar  26  and the wheels  30  and  32 . Axle wheel assemblies  34  and  36  may be utilized which are pivotally attached to the axle crossmember  22  of the frame  12  and the front wheels  30  and  32 , and which rotate or pivot as the handlebar  26  is rotated. The wheels  30  and  32  are typically rotatably coupled, such as by an axle or the like, to the axle wheel assemblies  34  and  36 . Assemblies and mechanisms for transferring rotational movement of a handlebar to one or more wheels are well known and can be incorporated in the present invention, and thus it will be appreciated that other types of handlebar assembles and steering mechanisms and assemblies can be incorporated into the present invention so as to enable the knee walker  10  to be controllably turned. Preferably, however, there are two wheels  30  and  32  at the front of the knee walker  10  so as to provide stability and support while the user is operating the knee walker  10 , such as preventing the knee walker  10  from tipping over easily during use. 
         [0032]    With reference now to  FIGS. 1 and 2 , the present invention contemplates the adjustability of the handlebar  26  relative to the user so as to raise or lower the handles or grips  28  to provide comfort and convenience to the user. This can be done, for example, by means of an adjustable clamp  38 , which upon being loosened allows the vertical tube or shaft  40  or the handlebar  26  to be raised and lowered within the steering tube  20  of the frame  12 . In a particularly preferred embodiment, the adjustment means comprises a quick lever clamp  38  which enables the handlebar tube  40 , which is telescopically received within the steering tube  20  to be raised and lowered, as needed. In one embodiment, as illustrated in  FIG. 2 , the handlebar  26  is also pivotally connected to the frame  12 , such that it can be pivotally lowered, as illustrated in  FIG. 2 , for transporting and storing the knee walker  10 , or raised uprightly, as illustrated in  FIG. 1  when in use. 
         [0033]    A knee supporting or rest pad  42  is attached to the frame  12 , such as by a support tube  44 . The knee pad  42  is of such a width and length so as to be able to place one&#39;s knee and a portion of the lower leg thereon to support, balance and stabilize the individual on the knee walker  10 , as illustrated in  FIG. 3 . As mentioned above, typically the user operating the knee walker  10  device will have an injury to his or her foot, ankle or lower leg, such as the result of an accident, surgery, or the like, which prevents the user  2  from placing weight on his or her foot, ankle, and/or lower leg and thus prevents the user from walking on that foot and/or leg. Placing the knee  4  and portion of the lower leg  6  onto the knee rest supporting pad  42  enables the user  2  to suspend his or her ankle and foot and lowermost portion of the leg so that pressure is not exerted thereon. 
         [0034]    Preferably, the knee rest support  42  is comprised of foam or other cushion material so as to provide comfort. As illustrated in  FIGS. 1-3 and 6 , in a particularly preferred embodiment, the knee rest pad  42  is designed so as to have a depression  46  formed therein on a top surface thereof such that the knee and lower leg can fit within the depression. However, the front  48  of the knee pad  50  does not have the depression, so that the knee of the user does not slide forward off of the knee rest pad  42 , such as when stopping the knee walker  10 . However, the rear end  50  of the knee rest pad  42  does have the depression and an opening, such that the lowermost portion of the leg, ankle and foot can extend therefrom, as illustrated in  FIG. 3 . 
         [0035]    With reference now to  FIG. 3 , in use, the user  2  places one of his or her knees  4  and lower legs  6  onto the knee rest pad  42  with the other foot on the ground or floor surface, as illustrated. The user  2  grasps the hand grips  28  of the handlebar  26  in order to be able to steer the knee walker  10 . The user  2  then utilizes his or her foot in contact with the ground to repeatedly push so as to propel the knee walker  10 , and thus the user  2 , forward. 
         [0036]    With reference to  FIGS. 1-5 , the knee walker  10  preferably includes a brake assembly for selectively slowing or stopping the knee walker  10  when in use. The brake assembly includes at least one manual brake lever  52  which is connected to a brake cable  54  which extends from the lever  52  to a brake mechanism  56  disposed adjacent to one or more of the wheels for stopping the rotation of the wheel. Although a variety of different types of brakes could be used in accordance with the present invention, in a particularly preferred embodiment, a disc  58  is coupled to the rear wheel  18  so as to rotate therewith and the braking mechanism comprises a pair of calipers and/or brake pads  60 , which are brought into contact with the brake disc  58  as the brake lever  52  is actuated by the user, causing the brake cable  54  to actuate the caliper  60 , causing the pads to come into contact with the disc  58  of the disc brake, causing the rear wheel  18  to increasingly slow down and stop, and thus the knee walker  10  to stop. The use of disc brakes increases performance and provides durability. 
         [0037]    As illustrated in  FIGS. 4 and 5 , preferably, the brake cable  54  enters into the frame  12 , such as the upper frame  14  through aperture  62  and extends through the hollow frame member  14  until it exits aperture  64  adjacent to the brake mechanism  56 . Aside from being visually appealing, this protects the brake cable  54  from being caught on objects which come into contact with the frame. 
         [0038]    The three-wheeled design of the present invention provides inherent benefits. The braking system is able to be coupled only to a single rear wheel  18 , resulting in manufacturing cost savings. In a four-wheel configuration two different sets of brake mechanisms would have to be associated with the rear wheels in order to avoid a sudden pulling movement to the left or right as the walker is stopped, which could cause instability of the walker. Having a single rear wheel  18  enables the overall footprint and size of the knee walker  10  to be smaller. Moreover, the knee walker  10  is able to be manufactured with only three wheels, instead of four wheels. 
         [0039]    With reference now to  FIG. 9 , in a particularly preferred embodiment, the frame is angularly offset, as illustrated, such that the front end of the frame and the rear end of the frame do not lie generally in the same plane, but instead the rear end of the frame is offset at a predetermined angle. That is, the rear end of the frame  12  which is coupled to the rear wheel  18  is offset to either the right or the left in order to center and align the rear wheel  18 , as well as the knee rest pad  42 , with the steering tube  20  and handlebar  26 . This provides additional stability and control to the knee walker  10 . 
         [0040]    The knee walker  10  of the present invention is also adjustable to accommodate users of different sizes. Adjustment clamp  38  can be actuated in order to enable the user to raise or lower the handlebar  26 , such as by means of the handlebar tube  40  being raised and lowered in a telescopic manner with respect to an outer tube, such as the steering tube  20  or an intermediate tube. Moreover, the knee rest pad  42  may be selectively raised and lowered. As illustrated in  FIG. 7 , a quick adjust lever  66  can be actuated by the user, such as by lifting up on the lever  66 , in order to move the seat post  68 , and thus the knee rest pad  42  upwardly or downwardly. The seat post tube  68  is telescopically received within an outer tube  70 , and lifting the quick adjust lever  66  enables the seat post tube  68  to be raised and lowered in any desired increment and to any height within the range of the tubes  68  and  70 . Releasing the lever  66  will automatically lock the tubes  68  and  70  in place with respect to one another, and thus lock the height of the knee rest pad  42  in place. Thus, the knee rest pad  42  can be adjusted upwardly and downwardly to meet the desired height for any individual&#39;s needs as the adjustment mechanism allows for endless iterations of height. In prior art knee walkers, there is either no height adjustability or limited height adjustability by a series of preset spaced apertures and a spring-loaded pin, requiring the height adjustment to be in increments of height in accordance with the spacing of the apertures. However, in accordance with the present invention, the adjustment mechanisms of the present invention allows for selectively adjusting the distance between the knee pad  42  and the frame  12  in any desired increment within the range of movement between the posts and the adjustment mechanism. 
         [0041]    The adjustability of the knee rest pad  42  also enables the knee walker  10  to be moved into a more compact state for transport and/or storage. The knee rest pad  42  would be lowered to its lowermost state. The handlebar  26  would be lowered to its most lowered state and/or folded downwardly, such as by actuating handlebar adjustment clamp  38 , as illustrated in  FIG. 2 . This more compact state enables the knee walker  10  to be more easily placed in an automobile for transport or stored when not in use. 
         [0042]    With reference now to  FIGS. 1-3,7 and 8 , in accordance with the present invention a suspension assembly  72  is disposed between the knee resting pad  42  and the frame  12 . This allows the knee support pad  42  to have a limited amount of vertical travel to provide comfort to the user&#39;s knee and leg as the user pushes his or her weight onto the knee support pad  42 , encounters uneven surfaces and the like. Such forces are dissipated by a shock absorber or suspension of the suspension assembly  72 . 
         [0043]    In a particularly preferred embodiment, the suspension is disposed immediately below the knee rest support pad  42 , such as being incorporated into the knee rest stem between the knee support pad  42  and the frame  12  of the device  10 , such that the forces that would otherwise be transferred directly up into the knee support pad  42  will be dissipated. For example, the suspension assembly  72  may comprise a telescopic mechanism having a damper between the knee rest pad  42  and the frame  12 . Preferably, the suspension device is incorporated within the tubing of the stem. Such suspension devices may be spring-based, elastomeric, or in a particularly preferred embodiment pneumatic. 
         [0044]    With reference to  FIG. 10 , a pneumatic suspension device embodying the present invention is shown. The suspension assembly  72  comprises a rod  74  having a piston  76  coupled to an end thereof. The movement of the rod  74  will correspond with the movement of the knee rest pad  42 , such as by being connected to stem tube  68 , the knee rest pad  42  directly, or intermediate components and linkages and the like. Movement of the piston  76  is dampened by virtue of air, or hydraulic fluid, which is compressed and decompressed as the frame  12  travels upwardly and downwardly as the knee walker  10  travels across uneven surfaces. 
         [0045]    As illustrated in  FIGS. 1-3 , the outer tube  70  of the suspension assembly  72  resides within the frame tube  44 . Thus, as the frame  12 , and thus the frame tube  44  moves upwardly and downwardly due to travel of the knee walker  10  across uneven surfaces, these forces are transmitted through the suspension assembly causing the rod  74  and the piston  76  to travel upwardly and downwardly, and to dampen these forces as they are transmitted to the knee rest pad  42 , such that the knee rest pad  42  travels upwardly and downwardly, but the forces are dampened and dissipated by means of the compression and decompression of the air or hydraulic fluid  78  or the like within the suspension assembly  72 . 
         [0046]    It will be understood that in place of a hydraulic or pneumatic piston arrangement, as illustrated in  FIG. 8 , a coiled spring or a compressible elastomeric pad or the like could alternatively be used. However in a particularly preferred embodiment, the suspension assembly  72  comprises a suspension seat post, as illustrated in  FIG. 8 , interconnecting the knee rest pad  42  and frame  12 . The important aspect of the present invention is that the upward and downward forces that would otherwise be transferred through the knee rest support pad  42  be dampened to provide comfort to the user of the knee walker  10 . 
         [0047]    It will be appreciated that the knee walker  10  can be used over prolonged periods of time as the individual is using the knee walker  10  in lieu of walking from location to location. This can create stress on the individual&#39;s knee and leg as he or she utilizes the walker  10  throughout the course of the day. Moreover, either due to the individual&#39;s lower leg, ankle or foot ailment, surgery, or the like forces that would otherwise be transmitted through the knee rest pad  42  could potentially cause pain to the area where the surgery was performed, the ailment or injury is or the like and be felt much more profoundly by such individuals if not dampened by the suspension assembly  72  of the present invention. While suspension devices could be placed associated with the wheels or the handlebar assembly, it is believed that these placements would not be nearly as effective in reducing the forces transmitted to the user&#39;s knee and lower leg, foot, etc. as the placement directly below the knee support pad  42 , as in the present invention. By placing the suspension in the vertical path of the weight bearing portion of the knee rest pad  42  provides the most relief of discomfort and dampening of stress transmitted at the contact point. This greatly reduces the hot spot sensation that many patients feel as they use other knee walkers for any prolonged period of time. 
         [0048]    There are times when the user will sit on the knee rest pad  42 , such as when stopped for a period of time and resting, waiting, or the like. It can be uncomfortable for the user to place his injured foot or ankle directly onto the ground or floor, and in many instances the user has a cast, boot, or protective bandaging surrounding the ankle and foot area. Thus, the present invention provides a foot rest platform  80  on top of the axle cross member  22 . As can be seen in  FIGS. 1 and 2 , the foot rest platforms  80 , on either side of the steering tube  20  of an enlarged area so that the user may comfortably place his or her foot thereon. As illustrated in  FIG. 10 , the foot rest platform has an angle ø of approximately 10°-30° such that the platform  80  is angled towards the user so that it is comfortable for the user to place is or her foot thereon. The angle of the foot rest platform  80  provides a natural resting angle for the foot and ankle so as to reduce the stress thereon. Anti-skid or other gripping material may be placed on the upper surface of the platforms  80  to prevent the user&#39;s foot from slipping off of the platform. 
         [0049]    Although several embodiments have been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.