Patent ID: 6966527

Claim:
A closed cable drag chain comprising a number of intermediate frames, removable opening/closing lid members and removable outer frame members, each of said intermediate frames includes an articulated outer peripheral side and an articulated inner peripheral side, said intermediate frame includes an intermediate frame body, each said intermediate frame body includes an inner portion, side wall portions, a front portion and a rear portion, each said intermediate body includes a cable holding groove residing in said inner portion, each said side wall portion includes an engagement portion, said front and rear portions include connecting portions, said removable opening/closing lid members are fitted to said engagement portions of said side walls, each said intermediate frame body includes upper and lower open end surfaces, said upper open end surfaces of each intermediate frame body are brought into contact with adjacent open end surfaces of adjacent intermediate frame bodies on said articulated outer peripheral side of said chain to maintain a straightly extended position and said lower open end surfaces of each intermediate frame body are brought into contact on said articulated inner peripheral side of said chain while circulating to maintain a required articulated position, said intermediate frames are articulately connected through said connecting portions, and said cable is inserted into said chain and said removable outer frames cover connecting spaces between said adjacent intermediate frames to close the respective connecting spaces between said adjacent intermediate frames, whereby said cable is held and guided, characterized in that: at least any one of said front and rear connecting portions of each of said intermediate frame bodies is integrally two-color injection-molded; a first polymer resin is used to form all portions of each of said intermediate frame bodies except said at least any one of said front and rear connecting portions of each of said intermediate frame bodies; and, a second polymer resin material softer than said first polymer resin material is used to form said at least any one of said front and rear connecting portions of each of said intermediate frame bodies; and, each of said removable opening/closing lid members includes front and rear bend limiting end portions and at least any one of said front and rear bend limiting end portions of each of said opening/closing lid members is integrally two-color injection-molded; said first polymer resin is used to form all portions of each of said opening/closing lid members except said at least any one of said front and rear bend limiting end portions of each of said opening/closing lid members; and, said second polymer resin material softer than said first polymer resin material forms said at least any one of said front and rear bend limiting end portions of each of said opening/closing lid members.