Coupling device and method for making a molded shoe sole

Abstract

An improved coupling device for a slipper or sandal-type footwear having two or more coupling devices for detaching the upper shoe part from the plastic sole. The coupling devices are distributed around the edges of the shoe upper and have teeth-like prongs which mesh with resilient tongues positioned within sockets that are embedded in the sole. Buttons are provided on the sidewalls of the sole for releasing the prongs from the sockets when it is desired to exchange the shoe uppers on the sole. The coupling device has an enclosing cap that, in a method for molding, prevents flowable resin from entering the socket and the air space around the button during the resin molding process, which could render the device inoperable.

1 . A coupling device for use in detachably coupling a shoe upper to a shoe sole to enable a user to assemble and disassemble the shoe at will, where the coupling device is molded into the shoe sole, the coupling device comprising: 
 (a) a socket having a shaft passage therethrough and comprising a tongue disposed in the shaft passage and having a plurality of ratchet teeth movable from an unbiased engaged position and a biased disengaged position in response to depression of a button affixed to the tongue, where the button extends through an opening in the socket,    (b) a plug having an upper portion affixable to the shoe upper; and at least one prong insertable into the socket and having a plurality of complementary ratcheted teeth that detachably engage with the ratcheted teeth of the tongue in its unbiased engaged position upon insertion of the plug into the socket, and    (c) a socket enclosure configured to surround the socket and button, to prevent flowable resin from entering the socket and the air space surrounding the button during molding of the sole.    
   
   
       2 . The coupling device according to  claim 2  wherein the socket further comprises an inner wall, and outer wall, and two connecting side walls, forming the shaft passage that has a slotted opening penetrable through a foot-bearing topside of the sole, the tongue is resiliently movable from a unbiased engaged position and a biased disengaged position and the button has a first rest position and a second depressed position, whereby when the button is in its rest position, the tongue is in its unbiased engaged position, and when the button is in the depressed position, the tongue is in its biased disengaged position.  
   
   
       3 . The coupling device according to  claim 1 , wherein the socket enclosure seals the shaft passage at the base.  
   
   
       4 . The coupling device according to  claim 1 , wherein the socket walls, tongue, stem and button are integral in a single piece.  
   
   
       5 . The coupling device according to  claim 1 , wherein the socket is formed with a thin membrane sealing off the orifice from the shaft to prevent flowable resin from entering the socket during molding of the sole, the membrane being breakable by pressing the button after the sole has been molded.  
   
   
       6 . The coupling device according to  claim 1 , wherein the socket enclosure comprising an outer resilient wall enclosing an air space environment surrounding the button.  
   
   
       7 . The coupling device according to  claim 6 , wherein the outer wall is convexly curved to provide resilient inward flexure.  
   
   
       8 . The coupling device according to  claim 7 , wherein the outer wall has a larger area for the finger than that of the button to apply the disengaging force.  
   
   
       9 . A shoe sole comprising an embedded socket of the coupling device according to  claim 1 .  
   
   
       10 . A method for manufacturing footwear, comprising the steps of: 
 (a) providing a socket having a shaft passage therethrough and comprising a tongue disposed in the shaft passage and having a plurality of ratchet teeth movable from an unbiased engaged position and a biased disengaged position in response to depression of a button affixed to the tongue, where the button extends through a opening in the socket, and a plug having an upper portion affixable to the shoe upper; and at least one prong insertable into the socket and having a plurality of complementary ratcheted teeth that detachably engage with the ratcheted teeth of the tongue in its unbiased engaged position upon insertion of the plug into the socket;    (b) providing a socket enclosure configured to surround a lower portion of the socket and the button,    (c) affixing the socket enclosure to the socket, thereby covering the opening to the shaft passage and enclosing the air space surrounding the button, and    (d) molding the socket into a resin-based shoe sole using a flowable resin, wherein the flowable resin is prevented from entering the socket and the air space surrounding the button.    
   
   
       11 . The method according to  claim 10 , the socket enclosure is a cap that snaps onto the bottom of the socket.  
   
   
       12 . The method according to  claim 10 , wherein the tongue of the socket is secured from movement during the molding process by pressure upon the button of the device.