Injection molded mushroom type hook structure and hook strap including the same

Abstract

One aspect of the present invention provides an injection molded mushroom type hook structure. The injection molded mushroom type hook structure of the present invention includes a stem portion and a substantially planar head portion formed at a top end of the stem portion, wherein the head portion includes two protrusion portions extending outwardly at two opposite sides of the head portion in a first direction, at least one extended portions extending outwardly from one side of the head portion in a second direction substantially perpendicular to the protrusions, and four connection portions that are formed at locations where the lateral sides of the two protrusion portions meet adjacent extended portion and the head portion. These structural features allow the injection molded mushroom type hook structure of the present invention to have a substantially same hook-to-loop engagement rate in each direction and an improved hook-to-loop engagement/peeling-off strength. Another aspect of the present invention provides an injection molded hook strap including the hook structure.

What is claimed is: 
     
         1 . A mushroom type hook structure comprising:
 a stem portion;   a substantially planar head portion formed at a top end of the stem portion, the head portion comprising:   two protrusions each protruding outwardly from a respective one of two opposite sides of the head portion in a first direction along a portion of a length of the side;   two extended portions each extending outwardly from a side of the head portion in a second direction that is perpendicular to the first direction along a substantial length of the side, wherein a free end of each of the extended portions curves downward slightly as a hook; and   four connection portions formed at locations where the lateral sides of each of the two protrusions meet adjacent lateral sides of each of the extended portions.   
     
     
         2 . An injection molded mushroom type hook structure according to  claim 1 , wherein the connection portion is a curved connection portion that has a radius of curvature R that is larger than or equal to 0.03 mm (R≥0.03 mm). 
     
     
         3 . An injection molded mushroom type hook structure according to  claim 1 , wherein the stem portion and the head portion are integrally formed as a single entity. 
     
     
         4 . An injection molded mushroom type hook structure according to  claim 1 , wherein the head portion has a polygonal contour. 
     
     
         5 . An injection molded hook strap comprising:
 a substrate; and   a plurality of injection molded mushroom type hooks according to  claim 1  integrally formed on a surface of the substrate.   
     
     
         6 . An injection molded hook strap according to  claim 5 , wherein the connection portion is a curved connection portion that has a radius of curvature R that is larger than or equal to 0.03 mm (R≥0.03 mm). 
     
     
         7 . An injection molded hook strap according to  claim 5 , wherein the stem portion and the head portion are integrally formed as a single entity. 
     
     
         8 . An injection molded hook strap according to  claim 5 , wherein the head portion has a polygonal contour.