Tips for ambulatory aids such as canes or crutches in use today are conventionally molded from rubber to have a flat or concave bottom surface about one and one-half to two inches in diameter. I have discovered that these conventional cane and crutch tips perform poorly for several reasons. First, because they are made of molded flexible rubber, conventional tips tend to slip on smooth floors, wet surfaces, and loose surfaces such as gravel and sand, resulting in a potentially dangerous situation for the user. Second, because these conventional tips are often flat bottomed, they must be placed precisely flat on the surface of the floor in order to provide stable support to their user. Third, I have found that conventional tips are often too small to provide adequate support on a ground surface covered by a loose material such as snow, sand or gravel. Conventional tips often sink several inches into loose sand and cause the user to lose balance or even fall, and I have noticed that many individuals have foregone the use of a cane in favor of a more stable, albeit cumbersome walker. Fourth, I have found that because conventional cane tips use a molded flexible rubber material, they tend to become unstable and wobble when in use. Fifth, because the conventional tips are made of molded flexible rubber and because there is little or no rigid material supporting these rubber tips, the conventional tips have a very limited life as they tend to crack easily with use. Thus, conventional cane tips often have to be replaced quite frequently.
There have been several efforts to overcome some of the above deficiencies. The Crutch Tip Construction of Urban, U.S. Pat. No. 4,630,626 proposes a tip made of a resilient, elastomeric rubber, an enlarged tip, and a rigid plastic or metallic socket for receiving the cane or crutch. A later effort, Wilkinson, U.S. Pat. No. 4,899,771 for a Walking Aid discloses a rocker shaped tip for a cane having a large rectangular bottom surface area and a pair of curved edges to permit the user to permit limited tilting of the cane or crutch during walking. Another effort, U.S. Pat. No. 4,098,283 for Specialized Crutch Tips to Tritle, Jr. provided a cane tip with a disk having a convex lower surface surrounded by a flat peripheral disk, or ride, to cut into and grab sand to prevent slippage. More recent designs such as the Radial Crutch Tip Assembly shown in U.S. Pat. No. 5,409,029 to Davis and the Walking Cane Usable on Slippery and Icy Surfaces in U.S. Pat. No. 5,301,704 to Brown rely upon a curved lower surface generally configured in the shape of a knob allowing the user to slightly tilt their appliance while walking. I have discovered however, that in use these knob-like tips tend to restrict the motion of the appliance to a direction lying within a plane parallel to the ground, a limitation that tends to make the use of the cane or crutch awkward while changing direction in mid-stride. Both designs purport to use a non-slip bottom surface.