1. Field of the Invention
The present invention relates to a friction device for footwear wherein a friction body such as a nonslip body to be used on footwear such as golf shoes is held on the sole of footwear by a holder being provided on the sole of footwear, and in particular, a friction device for footwear, which effectively prevents sand grains or the like from penetrating into any space between the friction body and the holder, and the friction body and the sole of footwear of said friction device for footwear.
2. Description of the Prior Art
For a nonslip body for golf shoes, which is an example of a friction body for footwear, metal and ceramic spikes have been used. In recent years, however, nonslip bodies of synthetic resins are used increasingly to prevent damages to the green, etc. and to improve the comfortableness to wear. Such nonslip bodies of synthetic resins, however, are easy to wear in comparison with metallic ones. Hence nonslip bodies of synthetic resins are provided with a fit-in protrusion, for example, a male screw of a metal or a synthetic resin, on their rear side, and the soles of the golf shoes are provided with holders, for example, holders having a female screw of a metal, which fits together with the male screw by screwing, so that the nonslip bodies can be detached and replaced as easily as possible.
However, when the nonslip body is fitted with the holder by screwing, etc. and held by the holder, if any of fine stone particles, sand grains, soil particles, lawn, dust, etc. penetrate into any space between the nonslip body and the holder, in particular, between the fit-in protrusion and the holder, it may become difficult to undo the fitting such as a screwed one, or the operation to undo the fitting may damage the holder or the friction body, or strained operation may cause injuries.
The present invention was made in view of the above-mentioned problems posed by the prior art, and one object of the present invention is to provide a friction device for footwear, which effectively prevents sand grains or the like from penetrating into any space between the friction body and the holder, any difficulties in undoing the fitting, any undoing operation of the fitting from damaging the holder or the friction body, and any strained operation from causing injuries, and to provide the friction body of said friction device for footwear.
The friction device for footwear according to the present invention comprises a friction body comprising a friction part, which is used in a state of being held on a sole of footwear to contact an object to be stepped on by the sole of footwear and generate frictional forces between itself and the object, a fit-in protrusion, which fits in and is detachably held by a holder provided on the sole of footwear, said fit-in protrusion being provided, in a condition being held on the sole of footwear, on the rear part of said friction part corresponding to the face of the sole of footwear and/or the surface part of the holder, and an annular rib or an annular groove, and an annular packing part, on said rear part of the friction part, on the outer circumference side of said fit-in protrusion, and
an annular groove or an annular rib corresponding to said annular rib or annular groove, and an annular packing part corresponding to said annular packing part, on the face of the sole of footwear and/or the surface part of the holder,
wherein one or both of said both annular packing parts is made of an elastic material, and
that when the fit-in protrusion is fitted in and held by the holder and the friction body is held on the sole of the footwear, said annular rib fits in said annular groove, and said both annular packing parts tightly and elastically contact and press each other over the entire circumference.
The friction body according to the present invention comprises a friction part, which is used in a state of being held on a sole of footwear to contact an object to be stepped on by the sole of footwear and generate frictional forces between itself and the object, and
a fit-in protrusion, which fits in and is detachably held by a holder provided on the sole of footwear,
wherein said fit-in protrusion is provided, in a condition being held on the sole of footwear, on the rear part of said friction part corresponding to the face of the sole of footwear and/or the surface part of the holder, and
that, of said rear part of the friction part, a part on the outer circumference side of said fit-in protrusion is provided with an annular rib or an annular groove, and an annular packing part.
The sole of footwear according to the present invention is a sole for footwear which is provided with a holder for fitting with and holding a fit-in protrusion of a friction body, said friction body comprising a friction part to be used in a state of being held on the sole of footwear to contact an object to be stepped on by the sole of footwear and generate frictional forces between itself and the object and the fit-in protrusion, wherein
on the face of the sole of footwear and/or the surface part of the holder, with said holder on the sole of footwear serving as the center, an annular groove or an annular rib, and an annular packing part are provided.
When the friction body is fitted with and held by the holder, if any of fine stone particles, sand grains, soil particles, lawn, dust, etc. penetrate into any space between the friction body and the holder, in particular, between the fit-in protrusion and the holder, it may become difficult to undo the fitting between them, or the operation to undo the fitting may damage the holder or the friction body, or strained operation may cause injuries.
In the case of this friction device for footwear, the friction body and the sole of footwear, an annular rib or an annular groove, and an annular packing part are provided on the rear face of the friction part of the friction body, in such a way that one is located on the inner circumference side of the other, and in correspondence with them, an annular groove or an annular rib, and an annular packing part are provided on the face of the sole of footwear and/or the surface part (sole of footwear) of the holder, and when the fit-in protrusion is fitted in and held by the holder and the friction body is held on the sole of footwear, said annular rib fits in said annular groove, and said both annular packing parts press and contact each other tightly and elastically over the entire circumference. In other words, when the friction body has the annular rib, the sole of footwear has the annular groove, and when the friction body has the annular groove, the sole of footwear has the annular rib.
When the footwear is in the state of use, namely, the fit-in protrusion of the friction body is fitted in and held by the holder provided on the sole of footwear, and the footwear is ready to step on the ground, the annular rib of the friction body or the sole of footwear fits in the annular groove of the other, and on the inner circumference side or the outer circumference side of them, the annular packing part of the friction body tightly and elastically contacts and presses the annular packing part of the sole of footwear over the entire circumference.
As described above, the double shielding structures, namely, the fit-in structure of the annular rib and the annular groove and the sealing structure of tight and elastic contacting and pressing of both the annular packing parts over the entire circumference, effectively prevent any foreign matters such as sand grains from penetrating into any space between the friction body and the holder, irrespective of any deformations that may be generated in various parts of the friction body and the sole of footwear when the footwear is used. Furthermore, the sealing structure by tight and elastic contacting and pressing over the entire circumference between both the annular packing parts can exhibit an effect of absorbing dimensional errors to some extent while preventing penetration of foreign matters.
Said friction body may have the annular rib or the annular groove on the outer circumference side of the annular packing part (preferably in the outer circumference edge part of the friction part). In this case, the annular groove or the annular rib corresponding to the annular rib or the annular groove of the friction body is provided on the outer circumference side of the annular packing part. The annular rib or the annular groove of the friction body may be located on the inner circumference side of the annular packing part.
The friction device for footwear according to the present invention may be one wherein said friction body has an outer circumference side annular rib or annular groove and an inner circumference side annular rib or annular groove on the outer circumference side and the inner circumference side of the annular packing part, respectively, and in correspondence with these annular ribs or annular grooves, an outer circumference side annular groove or annular rib and an inner circumference side annular groove or annular rib are provided on the outer circumference side and the inner circumference side of the annular packing part, respectively, on the face of the sole of footwear and/or the surface part of the holder, and when the fit-in protrusion is fitted in and held by the holder and the friction body is held on the sole of footwear, said respective annular ribs fit in said respective annular grooves and said both annular packing parts tightly and elastically contact and press each other over the entire circumference.
The friction body of this case has the outer circumference side annular rib or annular groove and the inner circumference side annular rib or annular groove on the outer circumference side and the inner circumference side of the annular packing part, respectively. The sole of footwear has, in correspondence with these annular ribs or annular grooves, the outer circumference side annular groove or annular rib and the inner circumference side annular groove or annular rib on the outer circumference side and the inner circumference side of the annular packing part, respectively, on said face of the sole of footwear and/or the surface part of the holder.
In the case of the above-mentioned friction device for footwear, the friction body and the sole of footwear, the annular packing part is provided on the rear part of the friction part of the friction body, and the outer circumference side annular rib or annular groove and the inner circumference side annular rib or annular groove are provided on the outer circumference side and the inner circumference side of the annular packing part, respectively, and in correspondence with them, the annular packing part and, on the outer circumference side and the inner circumference side of the annular packing part, the outer circumference side annular groove or annular rib and the inner circumference side annular groove or annular rib are provided on the face of the sole of footwear and/or the surface part of the holder (sole of footwear). When the fit-in protrusion is fitted in and held by the holder and the friction body is held on the sole of footwear, said respective annular ribs fit in said respective annular grooves, and said both annular packing parts tightly and elastically contact and press each other over the entire circumference. In other words, when the annular rib is provided on the corresponding position of the friction body, the annular groove is provided on the sole of footwear, and when the annular groove is provided on the corresponding position of the friction body, the annular rib is provided on the sole of footwear.
Moreover, the friction device for footwear according to the present invention is preferably one wherein, on the rear part of the friction part of said friction body, an outer circumference side annular rib is provided on the outer circumference edge part, and on the inner side of the outer circumference side annular rib an inner circumference side annular rib is provided and with an interval in between, and the annular part between both the annular ribs is formed into an annular packing face,
on the face of the sole of footwear of an elastic material, an annular packing protrusion corresponding to said annular packing face and an outer circumference side annular groove corresponding to said outer circumference side annular rib are provided,
on the face of the sole of footwear and/or the surface part of the holder, an inner circumference side annular groove corresponding to said inner circumference side annular rib is provided, and
when the fit-in protrusion of said friction body is fitted in and held by the holder and the friction body is held on the sole of footwear, said both annular ribs fit in said both annular grooves, respectively, and said annular packing face tightly and elastically contacts and presses said annular packing protrusion over the entire circumference almost in the direction in which the fit-in protrusion of the friction body fits in the holder.
When the footwear is in the state of use, namely, the fit-in protrusion of the friction body is fitted in and held by the holder, which is provided on the sole of footwear, and the footwear is ready to step on the ground, the annular packing part of said friction body tightly and elastically contacts and presses the annular packing part of the sole of footwear over the entire circumference, and on the outer circumference side and on the inner circumference side of them, the annular ribs of said friction body or said sole of footwear fit in the annular grooves of the other.
The triple shielding structures, namely, the fit-in structures of an annular rib and an annular groove on the outer circumference side and on the inner circumference side and the sealing structure of tight and elastic contacting and pressing, over the entire circumference, of both the annular packing parts being present between them, very effectively prevent any foreign matters such as sand grains from penetrating into any space between the friction body and the holder, irrespective of any deformations that may be generated in various parts of the friction body and the sole of footwear when the footwear is in use. The sealing structure by tight and elastic contacting and pressing over the entire circumference between said annular packing parts can also exhibit an effect of absorbing dimensional errors to some extent while preventing penetration of foreign matters.
The friction device for footwear according to the present invention comprises the friction body of the present invention, which is used in a state of being held on the holder being provided on the sole of footwear, annular grooves or annular ribs, and an annular packing part all being provided on the face of the sole of footwear and/or the surface part of the holder.
Footwear within the scope of the present invention may be exemplified by sporting shoes such as golf shoes, conventional low shoes, boots and sandals, and is not limited in any way. The sole of footwear means the sole of such footwear, and its material may be exemplified by synthetic rubbers and synthetic resins. The sole of footwear may be substituted with a part of any articles other than footwear, which requires friction against the ground surface, road surface, floor surface, etc.
The friction body comprises a friction part, which contacts an object to be stepped on by the sole of footwear and generates frictional forces between itself and the object, and a fit-in protrusion, which fits in and is detachably held by a holder provided on the sole of footwear. The fit-in protrusion is provided, in a condition being held on the sole of footwear, on the rear part of said friction part corresponding to the face of the sole of footwear and/or the surface part of the holder.
The friction body can be formed of synthetic resins (For example, nylon resins such as Nylon 6/6, polyurethane resin, polypropylene resin, and acrylonitrile-butadiene-styrene copolymer resin, etc. can be used according to circumstances. For example, for a part requiring certain levels of strength and rigidity, nylon resin such as Nylon 6/6 resin may be used, and for a part requiring a certain level of elasticity or flexibility, polyurethane resin, etc. may be used.), metals, ceramics, or combinations of these materials according to circumstances.
The friction part can be formed of synthetic resins, synthetic rubbers, metals, ceramics or combinations of these materials according to circumstances, to have, as a whole, a certain level of elasticity. The frictional forces that work between the friction part and the ordinary objects of friction (for example, the ground comprising soil, gravel, stone, rock, plants, etc., road surfaces of concrete, asphalt, stone, etc., floors of concrete, synthetic resins, stone, wood, etc., snow-covered surfaces, ice-covered surfaces, etc.) can be made greater than the frictional forces that work between the sole of footwear and the ordinary objects of friction.
The friction part may comprise, for example, a base and a plurality of protrusions protruding in a height direction, which is the direction from the base to an object at the time of use. Furthermore, for example, the part that touches the object of friction may be one having a flat face, one having minute ups and downs over the entire surface or in some parts, and one having a protruding part on the side of contacting the object of friction (for example, the bottom side of the sole of footwear) such as a group of small protrusions, a group of ribs, a group of straight ribs radially arranged or a group of ribs spirally and radially arranged. The entire configuration of the friction part may be, for example, an approximately plate-shaped body having a protruding part, and preferably, an approximately disk-shaped body.
The fit-in protrusion part may be, for example, one that is made of a material such as metals and synthetic resins and is provided protrusively on the rear of the friction part. Examples of such fit-in protrusion parts include, one having a male screw part on an outer circumference part, which is to be screwed in and held in a holder having a holding hole with a female screw and being provided on a sole of footwear, and one having a fit-in and holding mechanism other than a screw (when the fit-in protrusion and the holder being provided on the sole of footwear are provided with a fit-in holding mechanism that is based on rotation of an item other than a screw or that is not based on rotation). As for the friction body, one friction body or two or more friction bodies may be held on the sole of footwear.
Said holder to be provided on the sole of footwear may be formed of synthetic resins, metals, ceramics or combination of these materials. Such a holder may be used, for example, in a state of being buried and fixed in a sole of footwear, which is made of synthetic rubbers, synthetic resins, etc. (for example, shoe sole, in particular, sporting shoe sole such as golf shoe sole). Or such a holder may be integrally formed on such a sole of footwear, be integrally formed on the base of the sole of footwear to be used in a state of being exposed on the bottom of the sole of footwear.
The friction part has, on the rear part thereof, an annular rib or an annular groove, and an annular packing part (preferably concentrically) on the outer circumference side of the fit-in protrusion, or an outer circumference side annular rib or annular groove and an inner circumference side annular rib or annular groove (preferably concentrically) on the outer circumference side and on the inner circumference side of an annular packing part, respectively. The face of the sole of footwear and/or the surface part of the holder have an annular groove(s) or an annular rib(s) that is provided in correspondence with said annular rib(s) or annular groove(s), and an annular packing part that is provided in correspondence with said annular packing part. Both, the friction part, and the face of the sole of footwear and/or the surface part of the holder may have one extra or two or more extra annular rib(s) or annular groove(s), or one extra or two or more extra annular packing part(s) (preferably concentrically), each of which has a corresponding counterpart.
The sectional configuration of each annular rib and that of the corresponding annular groove may be arranged in such a way that, for example, when the fit-in protrusion is fitted in and held by the holder and the friction body is held on the sole of footwear, the rib and the groove can fit with each other almost without any gap between them, and at least, the base of the annular rib can contact (preferably contact and press) the edge of the opening of the annular groove (for example, the annular rib has a triangular section, which is tapered on the rear side of the friction part, and the annular groove has a square section, and the base of the annular rib contacts the edge of the opening of the annular groove).
Each annular rib may have a constant sectional configuration, for example, a triangular section which is tapered almost in the direction in which the fit-in protrusion of the friction body fits in the holder. When two or more annular ribs are provided, the height and configuration of each annular rib may be identical or different. For example, the annular rib on the outer circumference side may be higher than the other. When annular ribs are provided both on the outer circumference side and the inner circumference side, the interval or radial distance between them may be, for example, the height of a rib being not higher than other (the height of the lower one or the height of ribs when they have the same height) times about 0.7 through 3, preferably, about 1 through 2.
Either one or both of the annular packing part of the friction part and the annular packing part of the face of the sole of footwear and/or the surface part of the holder is made of an elastic material (for example, a synthetic rubber material), and as for their configurations, for example, one may be an annular packing protrusion, and the other one may be an annular packing face. Or both of them may be annular packing protrusions with a trapezoidal section. Or one may be an annular packing protrusion, and the other may be an annular packing concave. In any case, when the fit-in protrusion is fitted in and held by the holder and the friction body is held on the sole of footwear, both the annular packing parts tightly and elastically contact and press each other over the entire circumference almost in the direction in which the fit-in protrusion of the friction body fits in the holder.
It is desirable that the respective annular packing parts are integrally provided on the friction body, and the face of the sole of footwear and/or the surface part of the holder. In this sense, it is desirable that the annular packing part of an elastic material (in particular, the annular packing protrusion) is integrally provided on the sole of footwear made of a synthetic rubber material.
It is desirable that the annular packing protrusion has a longitudinal section of which width gradually decreases from the base towards the end almost in the direction in which the fit-in protrusion of the friction body fits in the holder. In this case, as the width of the longitudinal section of the annular packing protrusion decreases gradually from the base towards the end, the portion of the annular packing protrusion closer to the end thereof is easy to be compressed and deformed towards the base thereof. Hence the sealing effect by the elastic contacting and pressing between the annual packing protrusion and the counterpart annular packing part (for example, an annular packing face) over the entire circumference is enhanced.
It should be noted that an annular groove or an annular rib provided on the face of the sole of footwear and/or the surface part of the holder, and the annular packing part provided on the face of the sole of footwear and/or the surface part of the holder includes an annular groove or an annular rib, and an annular packing part provided on either one of the face of the sole of footwear and the surface part of the holder, and an annular groove or an annular rib, and an annular packing part provided across both the face of the sole of footwear and the surface part of the holder (for example, on their boundary part).
It is desirable that the above-mentioned respective annular ribs, respective annular grooves and respective annular packing parts are all concentric annuli, in particular, all concentric annuli having the axis of the fit-in protrusion in a state of the friction body being fitted in and held by the holder as the center. The reason for this is that it is convenient for realizing and maintaining the fitting between the annular ribs and the annular grooves and tight and elastic contacting and pressing between both the annular packing parts over the entire circumference when the friction body can be rotated on the axis of the fit-in protrusion or when the fit-in protrusion of the friction body and the holder provided on the sole of footwear can be fitted together and detached from each other by a fitting and holding mechanism relying on rotation of screws or structures other than screws (for example, a mechanism wherein fitting is maintained by rotation of the friction body in one direction and fitting is undone by rotation of the friction body in the other direction).
It is desirable that the outer circumference side annular rib is one provided in the outer circumference edge part of the friction body. In this case, when the friction body is fitted with and held by the holder, the annular body and the annular groove fit with each other in the outer circumference edge part of the friction part, hence penetration of any foreign matter into the space between the friction body and the face of the sole of footwear and/or the surface part of the holder is prevented effectively. The outer circumference side annular rib of this case may have a constant section of a triangle, wherein the outer circumferential face is cylindrical, and the inner circumferential face is a slope and the triangle is tapered towards the rear face of the friction part. With this arrangement, when the outer circumference side annular rib and the outer circumference side annular groove fit with each other, penetration of any foreign matter into the space between the friction body and the face of the sole of footwear and/or the surface part of the holder can be prevented more effectively.
When the fit-in protrusion of the friction body and the holder provided on the sole of footwear can be fitted together or detached from each other by a fitting and holding mechanism based on rotation of screws or structures other than screws, in a condition of being fitted and held together, the annular packing part of the friction part and the annular packing part of the face of the sole of footwear and/or the surface part of the holder tightly and elastically contact and press each other over the entire circumference, and they generate a resisting force against rotation of the friction body. Accordingly, inadvertent loosening of the friction body under the fitting and holding condition and eventual undoing of the fitting can be prevented.