Concealed slide fastener

Abstract

In a concealed slide fastener in which coupling elements 11, 13, 15 are injection moulded on the edge 25, 27 of a tape 17, 19 , a coupling portion 53 of a coupling element is provided on one side of the tape 17, 19 and a shelf 47 of the coupling element on the other side of the tape 17, 19 . A coupling portion 53 bears on the shelf 47 of the opposed coupling element with the respective tape 17, 19 sandwiched between them, to limit out of plane separation of the coupling elements. The coupling portion 53 can be made the full thickness of the coupling portion on one side of the tape without the need to provide any recess or undercut in the coupling head 43 and the coupling element can be moulded using a two part mould.

1 . A concealed slide fastener comprising a pair of stringers in which moulded coupling elements are provided on the edge of a respective tape, the coupling element including a body straddling the edge of the tape, a coupling portion extending from the body on one side of the tape and a shelf projecting from the body on the other side of the tape; when the coupling elements of the opposed stringers are engaged, the coupling portions of the coupling elements of one stringer bearing on the shelves of the opposed elements of the other stringer through the respective tape. 
   
   
       2 . A concealed slide fastener as claimed in  claim 1 , the coupling element further including projections formed so as to project from the body at each outer end on the side of the tape opposite to the side whereon the coupling portion extends from the body, the shelves being formed on the side of the projections which face the tapes. 
   
   
       3 . A concealed slide fastener as claimed in  claim 1  or  2 , wherein the coupling elements can be moulded only with a mould which can split into two mould parts substantially along the plane of the tapes. 
   
   
       4 . A concealed slide fastener as claimed in  claim 1 , wherein the tape is positioned at a mid plane of the body. 
   
   
       5 . A concealed fastener as claimed in  claim 1 , wherein two shelves are provided on a coupling element and a recess is formed between the shelves. 
   
   
       6 . A concealed slide fastener as claimed in any of  claims 1  or  2 , wherein the shelves of opposed coupling element are spaced from each other at such a distance as to allow the respective tapes to be interposed therebetween. 
   
   
       7 . A slide fastener as claimed in  claim 1  or  2 , wherein the coupling portion comprises a neck extending from the front face of the body and a head formed on the neck, and shoulders are formed on the body adjacent the neck, wherein the coupling portion abuts the adjacent opposed coupling portions at the shoulders and at the transition regions between the head and the neck.