Variable friction sole for bowling and other shoes

Abstract

The effective friction of a shoe is adjusted by changing the angle of a portion of the sole, relative to the shoe centerline. In one embodiment, the heel is effectively hinged and an adjustment device is spaced from the hinge axis, whereby the wearer can hold the shoe in one hand and manually adjust an actuator connected to a drive member that increases or decreases the angle of the hinge. The hinge axis can be perpendicular to the centerline, either in the front of the heel with the drive member embedded in the back of the heel, or in the back of the heel, with the drive member embedded in the front of the heel. Angulation can be effected in the foresole, about an axis perpendicular to the shoe centerline, or about an axis that is parallel to but offset from the centerline.

1 . A shoe having an adjustable weight bearing bottom surface, comprising: 
 an upper supported by a sole extending generally along a longitudinal centerline, said sole having an arch, a foresole defining a first weight bearing bottom surface longitudinally forward of the arch, and a heel defining a second weight bearing bottom surface longitudinally behind the arch, each of said first and second weight bearing surfaces having front and back regions and lateral side regions; and    an adjustment device at least partially embedded in the sole for selectively angulating one of said first or second weight bearing bottom surfaces in relation to said centerline.    
   
   
       2 . The shoe of  claim 1 , wherein the adjustment device includes a thumbwheel.  
   
   
       3 . The shoe of  claim 1 , wherein 
 said sole includes an exterior outsole having said bottom weight bearing surfaces and a midsole between the upper and the outsole;    said adjustment device spans said mid sole and outsole; and    said adjustment device selectively expands or contracts to push or pull the outsole away from or toward the midsole.    
   
   
       4 . The shoe of  claim 3 , wherein 
 said first or second weight bearing surface angulates about an axis on one side of the adjustment device, thereby forming a gap between the sole and midsole on the other side of the adjustment device; and    a curtain is provided over said gap between the sole and the midsole.    
   
   
       5 . The shoe of  claim 1 , wherein 
 said sole includes an exterior outsole having said bottom weight bearing surfaces and a midsole between the upper and the outsole;    the outsole and midsole are partially affixed to each other, leaving a gap therebetween and establishing a hinge axis; and    said adjustment device comprises a disc of varying thickness that spans said gap and is rotatable to selectively angulate the outsole relative to the mid sole.    
   
   
       6 . The shoe of  claim 1 , wherein 
 the adjustment device is in the heel;    the weight bearing surface of the heel is in one position, substantially flat and coplanar with the weight bearing surface of the foresole;    the heel angulates to other positions about an axis that is perpendicular to the shoe centerline; and    the adjustment device has an adjustment ranging in both positive and negative angles for the other positions, relative to said plane.    
   
   
       7 . The shoe of  claim 1 , wherein said adjustment device has a drive member at least partially embedded in the sole and an actuator connected to the drive member such that adjustment of said actuator angulates one of said first or second weight bearing surfaces in relation to said centerline.  
   
   
       8 . The shoe of  claim 1  wherein said adjustment device has a drive member at least partially embedded in the sole and an actuator connected to the drive member and accessible when the shoe is held in one hand, such that manual adjustment of said actuator angulates one of said first or second weight bearing surfaces in relation to said centerline.  
   
   
       9 . The shoe of  claim 8 , wherein the angulation is about an axis that is perpendicular to the centerline.  
   
   
       10 . The shoe of  claim 9 , wherein the angulation axis is in the front of the heel and the drive member is embedded in the back of the heel, such that said adjustment raises or lowers the back of the heel relative to the front of the heel.  
   
   
       11 . The shoe of  claim 9 , wherein the angulation axis is in the back of the heel and the drive member is embedded in the front of the heel, such that said adjustment raises of lowers the front of the heel relative to the back of the heel.  
   
   
       12 . The shoe of  claim 8 , wherein the angulation is in a direction around the centerline.  
   
   
       13 . The shoe of  claim 12 , wherein the drive member is embedded in the heel laterally of the centerline such that said adjustment raises or lowers one side of the heel relative to the other side of the heel.  
   
   
       14 . The shoe of  claim 12 , wherein the drive member is embedded in the foresole laterally of the centerline such that said adjustment raises or lowers one side of the foresole relative to the other side of the foresole.  
   
   
       15 . The shoe of  claim 8 , wherein 
 said sole includes an exterior outsole having said bottom weight bearing surfaces and a midsole between the upper and the outsole;    said drive member spans said mid sole and outsole; and    said actuator selectively expands or contracts said drive member to push or pull the outsole away from or toward the midsole at the location where the drive member is imbedded.    
   
   
       16 . The shoe of  claim 8 , wherein the actuator is a worm screw.  
   
   
       17 . The shoe of  claim 16 , wherein 
 the sole has an active portion defining said weight bearing surface and a base portion between the active portion and the footbed;    the worm screw has one end accessible at the weight bearing surface for receiving an adjustment tool and another end connected to a stationary disc bearing on the base portion; and    a movable member is supported in the active portion and threaded to the screw between the ends;    whereby rotation of the screw displaces the movable member along the screw, thereby displacing the active member commensurately.    
   
   
       18 . The shoe of  claim 16 , wherein a ratchet is operatively associated with the screw, for retaining the screw in a selected rotational position upon completion of the adjustment.  
   
   
       19 . The shoe of  claim 16 , wherein indicia are associated with the driven end of the worm screw and uniquely correlated to the rotational position of the screw.  
   
   
       20 . The shoe of  claim 8 , wherein indicia are associated with the actuator and uniquely correlated to the position of the drive member.  
   
   
       21 . The shoe of  claim 1 , wherein 
 at least one of the first and second weight bearing surfaces, for contacting the ground or a floor, comprises a plurality of materials that are present in predefined surface areas; and    the adjustment of the angulation changes the proportion of each material that contacts the ground or floor.    
   
   
       22 . The shoe of  claim 21 , wherein the shoe is a bowling shoe.  
   
   
       23 . The shoe of  claim 1 , wherein the shoe is a bowling shoe.  
   
   
       24 . The shoe of  claim 1 , wherein the shoe is a driving shoe.  
   
   
       25 . The shoe of  claim 1 , wherein the shoe is a court game shoe.  
   
   
       26 . In a bowling shoe having a substantially flat foresole and a substantially flat heel in substantially coplanar relation to the foresole for contacting a floor, the improvement comprising an adjustment device in the heel for angling the heel out of said substantially coplanar relation with the foresole.  
   
   
       27 . The bowling shoe of  claim 26 , wherein the heel has front and back regions, and the angling hinges the front or back region of the heel relative to the back or front region of the heel, respectively.  
   
   
       28 . The bowling shoe of  claim 27 , wherein the adjustment device has a neutral position in which the heel and foresole are substantially coplanar, and a range of adjustment about the neutral position including raising the front region relative to the back region and lowering the front region relative to the back region.  
   
   
       29 . The bowling shoe of  claim 27 , wherein one region has a surface having a first coefficient of friction and the other region has a surface having a different coefficient of friction.  
   
   
       30 . The bowling shoe of  claim 26 , wherein the heel has left and right side regions, and the angling hinges the left or right region of the heel relative to the right or left region of the heel, respectively.  
   
   
       31 . The bowling shoe of  claim 26 , wherein 
 the heel has a heel base in fixed relation to the footbed of the shoe and the underside overlying a movable heel outsole that contacts the floor in use;    the heel outsole has an internal cavity defined by an upstanding support wall extending from a transverse support surface up to close or contact relation with the underside of the heel base;    an active disc is fixed to the transverse support;    a passive disc is seated in fixed position for rotation at the underside of the heel base;    a worm screw spans the discs, fixed to the passive disc and threaded through the active disc;    an actuating end of the worm screw penetrates the transverse support surface for accessibility externally of the heel outsole;    whereby external rotation of the screw forces the active disc to move away from or toward the passive disc such that as the active disc and moves toward or away from the passive disc the heel outsole is displaced relative to the heel base to angle the heel outsole out of coplanar relation with the shoe foresole.