Safe structure of cord set for window curtain

Abstract

An improved safe structure of cord set for a window curtain includes a base, a plurality of towing cords, a shade body and a pulling cord unit. The shade body is provided for each towing cord with buckles and a connector for connecting an end of the towing cord. The connector includes a socket fixed on the shade body, an insertion connecting member connected with the socket for fixing an end of the towing cords, the insertion connecting member has a blind hole for placing therein an end segment of the towing cords, thereby blocking of the end segment in the buckle is prevented when the connecting member is released from the socket, the buckle has thereon a breaking slit, thereby the towing cord can be loosened and released from the buckle when it is exerted with an axial pulling force over a predetermined value.

1 . An improved safe structure of cord set for a window curtain, said curtain includes a base, a plurality of towing cords pending below said base, a shade body provided below said base to be controlled by said towing cords to manipulate actions of contracting/stretching, a pulling cord unit extending out of said base to connect with said towing cords to allow a user to manipulate said actions of contracting/stretching with said towing cords; said shade body is provided for each of said towing cords with a plurality of buckles for extending therethrough of said towing cord and with a connector for connecting an end of said towing cord; said improved safe structure of cord set is characterized in that:
 said connector includes a socket fixed on said shade body, an insertion connecting member insertion connected with said socket, caliber of each of said buckles allows extending of said insertion connecting member therethrough; said socket is provided with a jack which is provided on its two inner lateral sides with at least a pair of mutually symmetrical grooves; a front end of said insertion connecting member is a V shaped plug, while a rear end of said insertion connecting member is a connecting portion for connecting said cord set; said V shaped plug is provided in its middle with a spare slit for compression, and is provided on its two lateral sides with curved protruding portions in correspondence with said grooves; a tailing end of said connecting portion for connecting said cord set is provided with a guide hole for extending of said towing cord therethrough; a blind hole is in communication with said guide hole to make an end segment of said towing cord not protruding out of the surface of said connecting portion when being placed in said blind hole, in order that said insertion connecting member is released from said socket when said towing cord is exerted with an axial pulling force over a predetermined value, and in order that said end segment of said towing cord is prevented from protruding out of said surface of said connecting portion to block said buckle; said buckle is provided thereon with a breaking slit having a width smaller than that of a diameter of said towing cord, thereby said towing cord is released from said buckle when it is exerted with said axial pulling force over a predetermined value.   
     
     
         2 . The improved safe structure of cord set for a window curtain as in  claim 1 , wherein: said buckle is in a “D” shape, and said breaking slit is extended from a central position on an inner curved side of said buckle obliquely to a non-central position on an outer curved side of buckle. 
     
     
         3 . The improved safe structure of cord set for a window curtain as in  claim 1 , wherein: said jack is provided on its two inner lateral sides with two sets of mutually symmetrical grooves, said calibers of said two sets of mutually symmetrical grooves are different, so that when said curved protruding portions on said two lateral sides of said V shaped plug are engaged in one set of said grooves, a combining force is provided, different set of grooves provides different combining forces.