Versatile cost effective Bowden cable - has outer spiral tube of steel sheet hot press bonded to pref. fibre-reinforced low friction plastic film with per-fluoro-alkoxy adhesive

摘要

A Bowden cable system consists of an outer spiral tube, inner coaxial cable, and intermediate low friction polymer layer; the tube itself consists of a substrate and outer coating in the form of a low friction plastic film. This latter film is preferably PTFE bonded to its substrate with a perfluoroalkoxy adhesive, and preferably has fibre reinforcement(s). ADVANTAGE - The product saves material and operations in its production. It is versatile, it enables a wide variety of filling materials to be used, reinforcements can be used, and the substrates chosen to suit the applications concerned. In an example, a laminate is used for the spiral tube, consisting of 0.5 mm etched stainless steel sheet bonded to a 0.15 mm film of PTFE emulsion polymer with 25 wt.% aromatic polyester filler, using heat and pressure plus a thin film of perfluoralkoxy as adhesive. The laminate is cut into strips 2.75 mm wide and then made into spiral tubing of i.d. 3.3 mm. The finished Bowden cable was tested at -40 -/+ 150 deg.C under loads of 120-800 N, with amplitude +/- 50 mm, frequency 1 Hz and at least 1,000,000 cycles. After 3,000,000 cycles the test showed 91.2% effectiveness over the complete path, with 0.82 mm stroke in tension and pressure. (Dwg.3/3)