Abstract:
A pseudo-frustoconical shaped unitary rubber end unit for an ambulatory device, such as a cane, comprising, a bottom hexagonal base and a top circular rim, wherein said base is about four times the diameter of said rim and functions to provide significantly enhanced support and stability; and a central cylindrical “socket” created by six deeply recessed side walls and a resultant six member rib-like frame that functions to optimize device&#39;s shock absorption capabilities and forward propulsion of the user. The hexagonal base may be asymmetrical or symmetrical, and the ribs may be of uniform or non-uniform dimensions. The hexagonal base and the rib-like frame act synergistically to compress and rebound under loads creating a twisting “spring assist” action that both absorbs shock and helps propel users forward. The broad base has a slightly recessed underside permitting the mobility device to be self-standing.

Description:
PRIORITY CLAIMS TO RELATED PROVISIONAL APPLICATIONS 
       [0001]    The present application claims priority benefit to U.S. Provisional Patent Application Ser. No. 61/343,129, filed Apr. 23, 2010 by Michael E. Adams, entitled “6 sided substantially conical elastomeric broad base shock absorbing floor tip for canes and crutches”, the disclosure of which is incorporated by reference. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    This invention relates generally to tips and bases for canes and related ambulatory aids, and more specifically to those tips and bases having both sufficient size so as to markedly improve the support and stability of such devices, and an overall construction specifically designed to actively assist a user moving through a gait cycle. 
       BACKGROUND OF THE INVENTION 
       [0003]    Tips or bases of different sizes and configurations have long been fitted to the bottom end of canes and other ambulatory aids. To a greater or lesser degree, each is designed to absorb shock, increase support and stability, and improve the traction of the associated device. The traditional tip is a simple molded rubber piece press fitted onto the lower shaft of a cane or crutch. Typically conical in shape, it tapers from a narrow upper collar to a bottom rim approximately twice the shaft diameter, and features a concave underside with concentric rubber rings that contact the ground as the tip compresses. While preferable to a blunt wood or metal shaft, these tips contribute little to improving user comfort, safety or convenience. One of the most well-known conical tips is the “Tornado” Tip (U.S. Pat. No. 4,881,564) by Thomas Fetterman, Inc. Top quality materials and a resilient “core structure” between the bottom rim and the main body, and a “pivoting mid-section” combine to improve both shock absorption and traction. Improvements in overall support are marginal, however, and the combination of expensive materials and a sophisticated construction are reflected in its premium price. 
         [0004]    So called “quad” bases have long been the most popular alternative to conical tips. Rectangular plates with downward pointing, rubber tipped tubes at each corner, they are best known for providing improved stability when held at a user&#39;s side, and for making a cane self-standing when it is not in use. For all these benefits, however, quad bases offer just intermittent support, and are typically comprised of several cumbersome and heavy steel parts. Additionally, large gaps between the tubular legs, and the ease with which those legs can snag or catch on any number of surfaces, make quad bases a real trip hazard. The Quadruple Cane Tip by Sky MedSupply International Corporation shows four contact points configured in a cross-rather than a rectangular-orientation. While this does make a device self-standing, the deep voids between the “tip arms” still present a trip hazard, and the north/south/east/west orientation of the contact points is even more problematic than a typical quad base in terms of abrupt, “on again-off again” support. 
         [0005]    A newer alternative is the “Able Tripod” cane tip marketed by LA Care Industries, LLC. Three ground contacting lobes flare out from a central molded body with the forward facing lobe containing a strip of spring steel. The broad “footprint” made by the three lobes combines with the resilience of the spring to improve support and stability, while also actively assisting a user as they move through a gait cycle. However, the effectiveness of the spring-biased lobe in response to loads is highly variable, and the large voids between the lobes provide no support to stabilize the user throughout their gait. 
         [0006]    In addition to the tip and base styles outlined above, various manufacturers offer spring-biased conical tips, “articulated body” conical tips, rigid “tri” (three tip) bases, spring mounted quad bases, flexible molded plastic quad bases, and other variations on these themes. To date, however, no known device has been of sufficient size, configuration and construction to offer greatly enhanced support and stability, omnidirectional shock absorption and spring assist, an “unbroken” bottom rim, a self-standing feature, improved traction, and a low cost to manufacture all in a single product. Accordingly, there is a need within the art of tips for the ends mobility devices that provide support to a standing and walking user that offers these enhanced features: makes devices self-standing, increases support and stability for the user, optimizes shock absorption and floor traction; and actively assists users moving through a gait cycle by generating a “spring-like” forward propulsive force. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is a new type floor tip for canes and crutches that employs a novel, resilient shape to reconcile desirable functions and features of numerous competing designs in a single, simple device. More specifically, the present invention is a unitary molded rubber device that combines a squat, hybrid, main body-spring element with a shallow, ground contacting pad element, to increase user support, stability and safety, make an associated ambulatory aid self-standing, improve traction, absorb shock, and actively assist a user moving through a gait cycle. 
         [0008]    The present invention is directed to an improved tip for a mobility device, wherein the device is used to provide support to a standing user throughout their gait, such as a cane or crutch. The design of the present invention comprises a unitary molded rubber device of essentially a conical shape with a bottom hexagonal base and a top circumferential collar, otherwise known herein as a “pseudo-frustoconical shape”. Furthermore, it comprises: a hexagonal concave floor engaging base; six side walls with deeply recessed panels surrounded by a rib-like frame; and a top rim encircling a cylindrical cavity. This cavity houses the mobility device cane or crutch cylindrical tube, and thus is also known as the “central tube receiving socket”. The mobility device&#39;s cylindrical vertical tube, such as that found in canes or crutches, is press fitted to the tip of the present invention within the central tube receiving socket. 
         [0009]    The hexagonal base of the present invention is significantly wider in diameter as compared to the prior art, thus altering the dimensions and the functionality of the components of the end piece. The base is between about 100 and 130 millimeters in diameter; the “rib-like” frame lies at about a 40-50 degree angle above the horizontal plane; and in a preferred embodiment is about 45 degrees. The associated recessed panels are of about 37 to 41 millimeters in height; and the ribs of about 7 to 11 millimeters in thickness. This structural alteration provides enhanced levels of compressibility, otherwise known as shock absorption, and stability of the mobile device, while also providing a novel mechanism to affect forward propulsion of the user. 
         [0010]    In a further embodiment of the present invention, the ribs framing the mobility device tip are of two different sizes to enhance shock absorption, stability, and the forward propulsion of the user. From an overhead, cross-sectional view of the tip for forward motion, the two ribs in the tip front  1100  and  100  (at 11 and 1 o&#39;clock) and the two ribs in the tip rear  500  and  700  (at 5 and 7 o&#39;clock) are thicker than the two ribs on the tip sides  300  and  900  (at 3 and 9 o&#39;clock). The front and rear ribs are also slightly longer than the side ribs. Furthermore, the width of each rib may be uniform or not. All six ribs possess a wider end connecting with the bottom floor hexagonal base as compared to remainder of their rib length. The wider, terminal end of each rib at the floor engaging base improves stability, while the thinner mid-section of the ribs provides enhanced compressive and rebound forces and flexibility in the tip as a whole, while also providing a variably manifested “spring-like” force to assist in propelling the user forward. 
         [0011]    In another aspect of the present invention, the bottom floor engaging base is hexagonal in shape, and concave in a downwardly facing surface direction, and with a plurality of alternating rubber rings and recesses. Additionally, the perimeter, and tallest protrusion ring is quickly angled vertically from its outer rim towards the tip center such that the only point-of-contact of the mobility device with the floor when the device is in a vertical, unloaded position is the outer rim of the perimeter ring. This is for the purpose of minimizing the traction force that must be overcome when lifting the mobility device off the floor, while optimizing the traction and compressive forces when the mobility device is supporting the user&#39;s weight. As either vertical or oblique compressive forces are applied to the mobility device by the user, the perimeter protrusion ring laterally expands and flattens downward such that the entire diameter of the ring ultimately comes in contact with the floor. The plurality of alternating rubber rings and recesses provide enhanced traction and compression by permitting the floor engaging rings (e.g. protrusion rings) to laterally expand and thus maximize contact with the floor when under compressive loads. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention and its different aspects and advantages will be better understood from the following detailed description of preferred embodiments of the invention with reference to the following drawing: 
           [0013]      FIG. 1  is an elevated perspective view of the end piece or tip of the present invention. 
           [0014]      FIG. 2  is an overhead view of the present invention. 
           [0015]      FIG. 3  is a side, cross-sectional view of the present invention. 
           [0016]      FIG. 4  is an underneath view of the bottom end piece of the present invention. 
           [0017]      FIGS. 5A-C  are illustrations of snapshots in time through the gait of a user employing the present invention on his/her right side.  FIG. 5A  illustrates the end piece at the moment the device is placed in front of the user;  FIG. 5B  illustrates the end piece as the user is essentially parallel to and leaning vertically onto the device; and  FIG. 5C  illustrates the end piece as the user is completing his stride and the invention is unloading. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Previously, the prior art of the inventor of the present invention disclosed and claimed a mobility device comprising a hexagonal end tip as shown in U.S. Pat. No. 7,610,926 issued Nov. 3, 2009 entitled “Mobility Device”, the entirety of which is incorporated by reference. In particular, FIGS. 13-18 of U.S. Pat. No. 7,610,926 disclosed a pseudo-frustoconical shape with six facets or side walls  62 . Each side wall  62  includes a depressed panel  64  surrounded by an outstanding rib-like frame  66 , wherein the depressed panels are of a few millimeters in depth such that the side walls are almost vertical. The present invention is based on an unexpected discovery that a user of a mobility device experiences much increased stability, compressibility and measureable spring assistance to their ambulation when the end piece is re-modeled by dramatically increasing the depth of the depressed panels so as to make the resultant, circumferential ribs much more prominent. Additionally, a novel springing, or propulsive force is generated to assist the user in forward motion by the variably deflecting, twisting and rebounding action of the front, rear and side ribs. The springing action is further refined by the variable width of the front and rear versus the side ribs, and by modifying the individual ribs along their length such that they are thicker at the floor base than in the middle. For the purpose of the present invention, the term “about” is defined as +/−5%. 
         [0019]    The floor engaging end piece  58 , or otherwise known alternatively herein as tip, of the mobility device of the present invention comprises a frustum or pseudo-frustoconical shape, such that its basic shape is conical, but with the top tip removed so as to form a plane essentially parallel to the base. As shown in  FIG. 1 , the top plane is comprised of an outer circular rim  20  about 4 to 7 millimeters thick and about 22 to 32 millimeters in diameter (as measured from the outer rim) with an inner cavity, otherwise known as a central tube receiving socket  30  of about 1.25 inches to 1.75 inches, or 31.75 millimeters to 44.45 millimeters in depth. In a preferred embodiment as illustrated in  FIG. 1 , the central tube receiving socket  30  has a depth of about 1.5 inches, or 38.1 millimeters deep. As shown in  FIG. 3 , end piece  58  is press fitted (defined as the process by which the friction between two parts is sufficient to securely join them together) to the lower portion of a mobility device  14 , which is preferably formed from one-piece hollow metallic tubing such as aluminum and most preferably “aircraft grade” aluminum. End piece  58  may be made of rubber, or a resilient rubber-like plastics material. Preferably, end piece  58  is made from a molded elastomeric material which is solid in composition and semi-rigid in structure. In a preferred embodiment of the present invention, a flat support disc, preferably metal, may reside between the base of the cavity of the end piece and the metallic tubing  14 , as illustrated in  FIG. 3 , item  40 . The disc may comprise preferably about 1.5 to 2.5 millimeters in thickness and functions to prevent erosion of the end piece cavity bottom surface from various load forces exerted by the metallic tubing  14 . 
         [0020]    As illustrated in  FIGS. 1 and 2 , end piece  58  preferably has a pseudo-frustoconical shape with six facets or side walls wherein each side wall includes a vertical standing rectangular-like depressed panel  64  adjoined to an approximately horizontal standing trapezoidal-like ramp  68  surrounded by a rib-like frame  66 . The depressed panels  64  are about 90 degrees to the horizontal trapezoidal-like ramps  68 , while the rib-like frame lies about 40 to 50 degrees from a horizontal position. In a preferred embodiment, the rib-like frame lies at about a 45 degree angle from the horizontal. The end piece  58  height may range from about 2.0 inches to 2.5 inches; and the end piece floor engaging base may range from about 4.0 inches to 5.0 inches in diameter. The actual dimensions of each end piece  58  model is a function of the overall size of the mobility device for which it is designed. In a preferred embodiment, the end piece height is about 2.15 inches or 54.6 millimeters; and the floor engaging hexagonal base is about 4.5 inches or 114 millimeters in diameter. 
         [0021]    The rib-like frame of the present invention furthermore comprises, as illustrated in  FIG. 1 , six flexible “ribs”  66  extending from the top, outer rim  20  of the central tube receiving socket  30  to one each of the six points of the hexagonal base  72 . The six ribs are separated by the six adjacent, deeply recessed pockets, comprising the horizontal trapezoids  68  residing at about 90 degrees angle to the essentially vertical rectangular-like panels  64 . The ribs  66  may be of uniform size or not. In a preferred embodiment as exemplified in  FIG. 2  and as viewed overhead from the perspective of  FIGS. 5A-C , the front ribs  1100  and  100  (at 11 and 1 o&#39;clock in forward motion) and the rear ribs  500  and  700  (at 5 and 7 o&#39;clock) are thicker than side ribs  300  and  900  (at 3 and 9 o&#39;clock). Additionally, each rib may be of uniform thickness along its length or not. In the preferred embodiment, the width of front and rear ribs are thicker at the hexagonal base than in the rib midsection for the purpose of providing more compressibility and thus comfort to the user throughout their gait. 
         [0022]    As can be seen in  FIGS. 3 and 4 , for example, the bottom of end piece  58  is concave downward towards the floor wherein only the outer rim of perimeter ring  72  makes contact with the floor in an unloaded state as shown in the side view of end piece  58  in  FIG. 3  A view of the bottom, floor engaging part of end piece  58  shows that it is hexagonal in shape and is comprised of two non-touching six-sided rings  72  and  70  encircling a solid center pad  80 , wherein the rings are prevented from contacting each other via recesses  84  and  86 . It is an essential feature of the present invention that the rings are not touching so as to provide space for the rings to compress, laterally expand and maximize contact with the floor for optimal compression, stability and then rebound throughout a user&#39;s gait and range of motion. In a preferred embodiment of the present invention, the perimeter ring  72  possesses an inward angle of about 45 degrees such that only its outer rim contacts the floor in an unloaded state, and due also to the fact that the bottom ring  70  and the bottom center pad  80  are of less height than the perimeter protrusion ring  72 . The outer rim of perimeter ring  72  provides enough traction with the floor for the mobility device to be self-standing. 
         [0023]    BIOMECHANICAL OVERVIEW: As force is applied during a complete stride by the user of the mobility device attached to the present invention, the different portions of the end point  58  deform and progressively cooperate in a manner to maximize the shock absorption and stability afforded the user, as well as the type and degree of rebounding gait assistance provided.  FIGS. 5A-C  are illustrations of snapshots in time through the gait of a right-handed user employing the present invention for the purpose of substantially demonstrating the various “spring-like” actions performed by the novel structural elements of the present invention in response to the shifting loads it undergoes during the course of one complete stride. As shown in these figures, the recessed panels, rib-like frame and broad, compliant hexagonal base of the end piece cooperate with each other, variably deflecting and rebounding in a seamless fashion to provide substantial levels of support, stability and gait assistance. 
         [0024]      FIG. 5A  illustrates the present invention at the moment the device is placed in front of the right handed user at the beginning of a stride. The front of the hexagonal base is in an unloaded state, while the “left, inside rear” of the base (from an overhead perspective) is subjected to compressive loads, primarily inwardly deflecting the rib  700  (at the 7 o&#39;clock), and beginning to compress or flatten the underside of the bottom of the hexagonal base. 
         [0025]      FIG. 5B  illustrates the tip as the user is essentially parallel to, and leaning vertically onto the device. In this figure the axial compressive loads are maximized and principally absorbed by the inward deflection towards the ground and slight clockwise bowing (as viewed overhead) of the rib  900  (at 9 o&#39;clock), and, to a lesser extent, inward deflection and slight bowing in the counter-clockwise direction of rib  700  (at the 7 o&#39;clock). Additionally, the maximum compression and expansion of bottom rings  72  and  70  occurs during this phase of the gait (See  FIG. 3 ) such that the bottom hexagonal base is significantly depressed from ribs  700  to  900  to  1100 . 
         [0026]    And  FIG. 5C  illustrates the tip as the user is about to lift the device off the ground. At this point in the stride, the innermost rib  900  (at 9 o&#39;clock) is slightly bowed to the rear (e.g., counterclockwise), and the front inner rib  1100  (at 11 o&#39;clock) is partially deflected inward, and then-along with rib  900 -rebounds to its original shape as the device is lifted off the ground, cooperating with the rebounding/unloading force generated by the hexagonal base to help propel the user forward. 
         [0027]    The foregoing description and the accompanying drawings are illustrative of the present invention. Still other variations in arrangements or orientations of parts are possible without departing from the spirit and scope of this invention.