Abstract: A telescoping mast for supporting and raising a load may be telescopically extended by a zipper-action chain extension system further comprising a system for the management of one or more cables, such as power or communication cables traversing the length of the mast, and is capable of being locked into a rigid formation along a range of telescopic lengths.

Abstract: An elongated transmission chain is formed by roller assemblies and pairs of link plates extending in parallel spaced relationship outwardly of the roller assemblies to provide a pivotable connection therebetween. A master link pivotably connects the ends of the elongated chain and includes a pair of link plates overlapping the side plates of the roller assemblies at the ends of the chain. These master link plates have a pair of spaced apertures therein which are coaxially aligned with the apertures in the adjacent rollers of the roller assemblies at the ends of the chain. A pair of threaded fasteners seat in these apertures and extend between the master link plates and through the side plates and rollers. These fasteners are threadably engaged in assembly with the master link plates and are of length not greater than the spacing between the outer surfaces of the master link plates so that they do not extend outwardly thereof.

Abstract: A chain joint for a power transmission chain comprises a joint pin and a projecting bush having brims swelling outwardly both its ends with at least one a slit extending longitudinally through the bush. The projecting bush is inserted into a pin hole and a bush hole of the chain, and the joint pin is pressed in an inner hole of the projecting bush. Then, the projecting bush is spread outwardly due to the slit and fits in the pin hole perfectly. Furthermore, the brims engage with the outer link plates on their outsides to prevent the projecting bush from coming off.

Abstract: An improved articulate chain (10) including pivotally interconnected sections (12,14,16) of spaced, coacting links (18,20,22) having the chain driving members (54) intermediate the pivot connections (58,60) to reduce the chain loads thereon. The links (18,20,22) are locked together in a common plane (56) by integral externally splined projections (82) extending therefrom into the internally splined drive bushing (96) to resist torque loads and increase the structural integrity of the chain (10). The links (18,20,22) are releasably coupled together to permit expeditious disassembly and reassembly thereof for servicing.