GRINDING APPARATUS AND ASSOCIATED FOOTWEAR
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a grinding apparatus for attachment to footwear, and the footwear associated therewith. More particularly, the present invention relates to a grinding plate and footwear to which the grinding plate can be attached. Grinding is an activity usually associated with skateboards or in-line rollerskates, and involves sliding the bottom of the skateboard or in-line rollerskate along a hard surface such as concrete or metal in such a way that the wheels do not contact the hard surface. The sliding or scraping is referred to as grinding. Usually the lengthwise axis of the skate or skateboard is transverse to the direction of movement of the skater.
2. Description of the Prior Art
Grinding has early origins is skateboarding where the skateboards moved back and forth in a concrete half cylinder. At the edge of the cylinder the skateboarders began sliding the bottoms of the skateboards along the edge before rolling back down the half cylinder or pipe. In these maneuvers the wheels of the skate or skateboard are transverse to the direction of skate or skateboard movement. As a result the bottom of the skate or skateboard scraps or grinds against the surface being ridden over, and thus the term grinding.
While skateboarders are familiar with grinding, with the advent and greater appeal of in-line roller skates and the corresponding intricate movements, grinding has become an even more popular activity.
SUMMARY OF THE INVENTION
The inventor of the present invention has developed a shoe and grinding plate which allows people to experience and enjoy the activity of grinding without wheels or wheeled vehicles. The grinding plate of the present invention is intended to be attached to the side of the shoe of the present invention. The grinding plate can be attached to either the medial or lateral side of the shoe, or both medial and lateral sides. The grinding plate may be curved to have a substantially U-shape and runs across the bottom of the shoe from the medial to the lateral side of the shoe.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described with respect to the following drawings in which:
FIG. 1 is a perspective view of a shoe and grinding plate according to a first embodiment of the present invention;
FIG. 2 is a bottom view of the shoe and grinding plate shown in Fig. 1 ;
FIG. 3 is a perspective view of an insert molded unit for a shoe to support a grind plate in a second embodiment;
FIG. 4 is a perspective view of a shoe and grinding plate incorporating the insert mold unit of Fig. 3 ;
FIG. 5 is perspective view of the shoe shown in Fig. 3 with a strap to stiffen the midfoot;
FIGS. 6a and 6b are side views of grinding plates according to a second embodiment of the present invention;
FIGS. 7a and 7b are perspective views of the shoe shown in Fig. 4 without a grind plate and with a multiple piece sole;
FIG. 8 is a detailed side view of a shoe and grinding plate according to a third embodiment of the present invention;
FIG. 9 is a bottom view of the shoe and grinding plate shown in Fig . 7 ;
FIG. 10 is a bottom view of a shoe and grinding plate according to a fourth embodiment of the present invention;
FIG. 11 is a cut-away side view of the sole of the shoe shown in Fig. 3;
FIG. 12 is bottom view similar to Fig. 9 having a different grinding plate;
FIG. 13 is a bottom view of the shoe and grinding plate according to a fifth embodiment of the present inven ion;
FIGS. 14a and 14b are bottom views of a shoe and grinding plate according to a sixth embodiment of the present invention;
FIGS. 15a- f are side view of grinding plates similar to the grinding plates shown in Figs. 6a and 6b according to the present invention;
FIG. 16 is a perspective view of a shoe according to the present invention with the sole cut away for a heel grind plate;
FIG. 17 is an end view the shoe of Fig. 16;
FIG. 18 is perspective view of the sole of a shoe according to the present invention having a full length shock pad and separate shock pads for the fore-foot and heel;
FIGS. 19a and 19b are a perspective view and an end view of the sole of a shoe according to the present invention having a lateral flange for heel grinding extending laterally from a heel of the shoe; and
FIG. 20 is a bottom view of a shoe according to the present invention with a midfoot shank to strengthen the shoe during grinding shown in phantom.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figs. 1 and 2, a first embodiment of the present invention is illustrated. Fig. 1 shows one of a pair of footwear 20 for grinding according to the present invention. The footwear or shoe 20 is designed so that a wearer can walk in it in a normal manner in addition to using it to perform grinding maneuvers. The shoe, while also having elements found in ordinary shoes, includes a grind plate 25. In the embodiment shown in Figs. 1 and 2 the grind plate 25 is U-shaped and runs widthwise across the bottom of the shoe 20 from the medial side to lateral side of the shoe 20. The grind plate 25 is made from either metal, plastic, such as high density polyethylene nylon or Ptex™, or nylon. The shoe 20 may also have additional protection such as toe grind protector 30 and heel grind protector 35. The toe grind protector 30 and heel grind protector 35 are made from material hard enough to withstand repeated scraping against metal, concrete, and other similar hard substances. The arc of the U-shaped grind plate 25 can vary across the arch of the shoe 20. While the grind plate 25 of Figs. 1 and 2 runs straight across the width of the shoe 20, the grind plate 25 can have many different shapes. For example Fig. 13 shows another embodiment in which the grind plate 25 runs from the toe to the heel of the shoe 20. Similarly, Figs. 14a and 14b show embodiments where the grind plate 25 is U-shaped and extends across the width of the shoe 20. However, unlike the embodiment shown in Figs. 1 and 2, the grind plate 25 does not run directly across the width of the shoe but is angled so that the grind plate is further forward on the lateral or medial side of the shoe 20 than on the opposing medial or lateral side.
The grind plate 25 does not have to be U-shaped, as shown in the embodiment of Figs . 1 and 2. An insert molded unit 40 is shown in Fig.3, and is designed to fit in the midsole and/or outsole of a shoe. The insert molded unit 40 has a recessed channel 42, similar to the U-shaped configuration of the grind plate 25 of the first embodiment. The edge 44 of the insert molded unit 40 has threaded holes 46. The edge 44 shown
in Fig. 3 is the medial side edge of the shoe, but it can be the lateral side edge or both the medial and lateral side edges. The insert molded unit 40, in addition to providing attachment for a grind plate {not shown), adds strength to the complete sole. The insert molded unit 40 of Fig. 3 is intended to be used with grinding plate 25' and 25" as shown in Figs. 6a and 6b. Unlike the U-shaped grind plate 25 shown in Figs. 1 and 2 the grinding plates 25' and 25" do not run along the bottom of the shoe 20, but rather are intended to run along the side of the shoe 20. The grind plate 25' shown in Fig. 6a is pre-molded or shaped so that it has a U-shaped groove 48 along its lower edge 48. The grind plate 25", shown in Fig. 6b, is not pre-molded or shaped and thus its lower edge 48 is flat. Both grind plates 25' and 25" have a pair of holes 49 in them, corresponding to the holes 46 in the insert molded unit 40. The grind plates 25' or 25" are attached to the insert molded unit 40 by threaded screws (not shown) . The grind plates 25' and 25" can be made from either metal or a plastic such as nylon.
The insert molded unit 40 is incorporated in the shoe 20 in Fig. 4. The midsole/outsole 27 of the shoe 20 is cut away to allow room for the grind plate 25' in such a way that the grind plate 25' does not come into contact with the ground during normal walking. The grind plate 25" can also be used in place of grind plate 25' . A power strap 50 is shown in Fig. 5 extending around the heel 21, over the tongue 22 and under the heel 23 of the of the shoe 20. The power strap is provided to strengthen the midfoot 24 of the shoe 20 thereby enabling the wearer to perform more aggressive street maneuvers, such as grinding, sliding, jumping, and combinations thereof. The strap 50 can be formed internal to the shoe 20, and may be removable. An external power strap 50 may be made from nylon webbing and have hook and loop fasteners. The power strap 50 may be made as an integral part of the shoe 20, installed at production by either sewing to the interior or to the exterior of the shoe 20.
Figs. 15a-15f shown alternative configurations of the grind plate 25 than those shown in Figs. 6a and 6b. The location
of the groove 48 can vary from the front, middle and rear portion of the lower edge 49 of the grind plate 25 as shown in Figs. 15a- 15c. Similarly, the depth of the groove 49 can be considerably smaller and simultaneously have its location vary from rear to middle or front of the lower edge 49, as shown in Figs. 15d-15f . The shoe 20 is shown in Figs. 7a and 7b without a grind plate 25. The sole 31 of the shoe 20 has two parts fore-sole 32 and aft-sole 33. Fig. 7a shows the fore-sole 32 and aft-sole 33 attached to the shoe 20, while Fig. 7b shows the fore-sole 32 and aft-sole 33 separated from the shoe 20. By making the sole 31 from separate parts 32 and 33 a void is created in the mid-sole for accommodating the insert molded unit 40. The fore-sole 32 and the aft-sole 33 provide grind protection to the shoe 20 so that it shoe will not wear out in these areas due to grinding. The fore-sole 32 and the aft sole 33 can be laminated pieces that are attached to the shoe 20 and eliminate the need for a separate grind plate 25. The fore-sole 32 and the aft sole 33 would be attached between the upper and lower of the shoe 20 thereby offering a simplified version of grinding. A more detailed side view of grinding plate 25' is shown in Fig. 8 attached to an out-sole 31 of shoe 20. The pair of holes 49 in grind plate 25' are oval here to allow for adjustment of the position of the grind plate along the length of the shoe 20. The bottom of the out-sole 31 has a groove similar to the groove 48 on the bottom edge of the grind plate 25' . Referring to Fig. 9 the threaded holes 48 in the sole 31 can extend all the way through the sole 31 from the medial side to the lateral side. In such a configuration, the grind plate 25 can be attached to the medial side, the lateral side, or both the medial and lateral sides of the shoe 20. The threaded holes are formed integrally with the sole 31 during the manufacturing process .
Fig. 10 shows a cut-a-way bottom view of another preferred method of attaching the grind plate 25. Instead of having the holes 48 run all the way through the sole 31, separate T-shaped inserts 60 are formed in the sole 31. Each T-shaped insert 60 has a hollow threaded base portion 61, to accommodate
screws attaching the grind plate 25, and a flange 62 to anchor the insert 60 in the sole 31. The grind plate 25 is attached with two screws 70 which thread into the holes 48 in the T-shaped inserts 60. Unlike the embodiment shown in Fig. 9, the holes 48 on opposite sides of the sole 31 do not have to coplanar. As a result, the grind plate can be attached in a manner so that it better follows the contour of the side of sole 31.
The sole 31, shown in Figs. 9 and 10, also has cushioning or shock absorbing material 80 provided therein. The cushioning or shock absorbing material 80 is preferably made from elastomeric polymer material to deaden impact on the forefoot or heel. The cushioning or shock absorbing material 80 could run through the entire foot in the mid-sole or out-sole. The placement of the cushioning or shock absorbing material 80 can be seen clearly in Fig. 11, between the mid- sole and the out- sole.
Referring to Fig. 18, the shock absorbing material 80 can run the full length of the shoe 20 and be disposed underneath the insole of the shoe 20. Additional shock absorbing pads 91 and 92 may be positioned under the heel and the fore-foot of the shoe, respectively.
The grind plate 25 need not be a single plate which is flat on both sides. As shown in Fig. 12, the grind plate 25 can have a flat outer surface 85 and a shank 86 projecting trans- versely from the flat outer surface 85 under the sole 31. The shank 86 may be curved so that it conforms to curve of the side of the shoe 20. Such rounding off of the shank 86 reduces pressure from the shanks edge on the plantar surface of the foot and provides an even transition from supported to unsupported areas. The shank 86 can be inserted in between the midsole and the outsole and acts to strengthen the lateral stiffness of the shoe 20 to aid in the performance of aggressive maneuvers.
Heel stiffeners may be inserted in the heel counter of the shoe 20 to strengthen the shoe 20 for normal walking. Furthermore, a semi-rigid foot support or shank 100 as shown in Fig. 20 can be included in the shoe to help keep the shoe 20 from counterflexing while grinding. In the embodiment illustrated in
Fig. 20 the shank 100 is disposed in the middle of the sole of the shoe at the mid- foot. The shank 100 can be made from graphite or metal. The shoe 20 of Fig. 20 has two grind plates 25, one each on the lateral and medial sides of the shoe 20. The shank 100 in the midsole strengthens the middle of the shoe 20 and eliminates bending over the grinding surface (s) . The semirigid foot support can be in conjunction with the shank 86 and be placed through the midfoot to strengthen the midsection of the shoe where the most pressure is applied. Alternatively, a medial and lateral bracing system could be employed to keep the shoe 20 from counterflexing while grinding.
The U-shaped type plate shown in Figs. 1 and 2 can be attached in the same manner as the side mounted grind plate 25 in Fig. 8, by using T-shaped inserts in the mid-sole/out-sole and screws 70.
A grind plate 25 can be attached on the lateral heel aspect of the shoe 20 as shown in Figs. 19a and 19b where a lateral flange 25''' projects from the side of the shoe 20 for "locking on". Such a protrusion could be insert molded or be an integral part of the mid-sole/out-sole combination. Instead of screws 70 the grind plate 25 can be removably attached by a quick release type system so that the grind plate can be rapidly changed without requiring tools, for example when the shoes are to be worn just for walking. Finally, a heel grind plate 110 may be provided as shown in Figs. 16 and 17, where a portion of the sole 31 is cut away to accommodate a grind plate on the heel of the shoe 20. Such a grind plate can be attached with T-shaped inserts 60 and screws 70 as discussed previously. Having described several embodiments of the grinding plate and shoe in accordance with the present invention, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the description set forth above. It is therefor to be understood that all such variations, modifications and changes are believed to fall within the scope of the invention as defined in the appended claims .