Strap-on shoe anti-slip device

Abstract

A strap-on shoe anti-slip device includes a ground-contacting belt-like main body connected at two lateral ends to two extension straps, and a fastening unit having a male and a female fastener separately assembled to outer ends of the two extension straps. The male fastener can be detachably connected to variable positions on the female fastener for the strap-on shoe anti-slip device to form a circumference-adjustable loop structure, which internally defines a size-adjustable opening for a front portion of a shoe to extend therethrough and be bound thereto. The fastening unit is operable to selectively open or close the loop structure. The belt-like main body is provided on an underside with an anti-slip element, which may be differently configured to provide different anti-slip effects. A user may conveniently change shoes to have a specific anti-slip effect by selecting a strap-on shoe anti-slip device with a suitably configured anti-slip element.

What is claimed is: 
     
         1 . A strap-on shoe anti-slip device, comprising:
 a belt-like main body including a thin strip of pad matching a width of a shoe and an anti-slip element integrally formed on an underside of the pad; and the thin strip of pad having a left end defining a first end line and a right end defining a second end line;   a left extension strap defining a first inner end line and a first outer end line, and being connected at the first inner end line to the first end line of the pad;   a right extension strap defining a second inner end line and a second outer end line, and being connected at the second inner end line to the second end line of the pad; the right extension strap being adapted to connect at the second outer end line to the first outer end line of the left extension strap for the strap-on shoe anti-slip device to form a loop structure, which internally defining an opening for a front portion of a shoe to extend therethrough and be bound thereto; and   a fastening unit being assembled to the first outer end line of the left extension strap and the second outer end line of the right extension strap, and being operable to selectively open or close the loop structure.   
     
     
         2 . The strap-on shoe anti-slip device as claimed in  claim 1 , wherein the fastening unit includes a male fastener and a female fastener, and the male fastener being adapted to engage with the female fastener at variable positions thereon, whereby a circumference of the loop structure and a size of the opening can be adjusted via the male and female fasteners. 
     
     
         3 . The strap-on shoe anti-slip device as claimed in  claim 1 , wherein the fastening unit includes a male fastener and a female fastener, the male fastener being adapted to engage with the female fastener at an invariable position thereon; and the left extension strap and the right extension strap being made of an elastic and extensible material to allow elastic adjustment of the loop structure to different circumferences and accordingly adjustment of the opening thereof to different sizes. 
     
     
         4 . The strap-on shoe anti-slip device as claimed in  claim 1 , wherein the anti-slip element includes a plurality of round recessed areas sunken into an underside of the thin strip of pad; and the round recessed areas functioning like suction cups and having different diameters to thereby include a plurality of larger suction cups and a plurality of smaller suction cups. 
     
     
         5 . The strap-on shoe anti-slip device as claimed in  claim 1 , wherein the anti-slip element includes a plurality of grooves sunken into an underside of the thin strip of pad; and the grooves forming shoe tread patterns. 
     
     
         6 . The strap-on shoe anti-slip device as claimed in  claim 4 , wherein the thin strip of pad has a front portion with a predetermined thickness sufficient for effectively forming the round recessed areas thereat without extending through the pad, and the thickness at the front portion of the pad gradually reducing toward a rear portion of the pad. 
     
     
         7 . The strap-on shoe anti-slip device as claimed in  claim 1 , further comprising at least one ornament connected to an outer surface of one or more of the left extension strap, the right extension strap and the fastening unit. 
     
     
         8 . A strap-on shoe anti-slip device, comprising:
 a belt-like main body including a thin strip of pad matching a width of a shoe, and a set of replaceable anti-slip elements removably attached to the thin strip of pad; and the thin strip of pad having a left end defining a first end line and a right end defining a second end line;   a left extension strap defining a first inner end line and a first outer end line, and being connected at the first inner end line to the first end line of the pad;   a right extension strap defining a second inner end line and a second outer end line, and being connected at the second inner end line to the second end line of the pad; the right extension strap being adapted to connect at the second outer end line to the first outer end line of the left extension strap for the strap-on shoe anti-slip device to form a loop structure, which internally defining an opening for a front portion of a shoe to extend therethrough and be bound thereto; and   a fastening unit being assembled to the first outer end line of the left extension strap and the second outer end line of the right extension strap, and being operable to selectively open or close the loop structure.   
     
     
         9 . The strap-on shoe anti-slip device as claimed in  claim 8 , wherein the fastening unit includes a male fastener and a female fastener, and the male fastener being adapted to engage with the female fastener at variable positions thereon, whereby a circumference of the loop structure and a size of the opening can be adjusted via the male and female fasteners. 
     
     
         10 . The strap-on shoe anti-slip device as claimed in  claim 8 , wherein the fastening unit includes a male fastener and a female fastener, the male fastener being adapted to engage with the female fastener at an invariable position thereon; and the left extension strap and the right extension strap being made of an elastic and extensible material to allow elastic adjustment of the loop structure to different circumferences and accordingly adjustment of the opening thereof to different sizes. 
     
     
         11 . The strap-on shoe anti-slip device as claimed in  claim 8 , wherein the thin strip of pad is provided with a plurality of through holes corresponding to the set of replaceable anti-slip elements, and each of the replaceable anti-slip elements includes a forward protruded anti-slip body and a stop flange located around a bottom of the anti-slip body; the stop flange having an overall diameter larger than a diameter of the through hole, and the anti-slip body having a predetermined height sufficient for the anti-slip body to extend through the through hole and project from the thin strip of pad by a desired distance. 
     
     
         12 . The strap-on shoe anti-slip device as claimed in  claim 11 , wherein the anti-slip body has a tip with a predetermined width, which is selectable according to different environment requirements. 
     
     
         13 . The strap-on shoe anti-slip device as claimed in  claim 11 , wherein the anti-slip bodies are downward extended from an upper side of the thin strip of pad through the through holes to project from an underside of the pad, while the stop flanges are abutted on the upper side of the pad around the through holes and fixedly clamped in place between the upper side of the pad and an outsole of the shoe, preventing the replaceable anti-slip elements from moving relative to the through holes or separating from the thin strip of pad. 
     
     
         14 . The strap-on shoe anti-slip device as claimed in  claim 8 , further comprising at least one ornament connected to an outer surface of one or more of the left extension strap, the right extension strap and the fastening unit.