GB846162A - Improvements in chain or belt tensioning devices - Google Patents

Abstract

846,162. Belt and chain tensioning. PERRY CHAIN CO. Ltd. Oct. 31, 1958 [Dec. 12, 1957], No. 38599/57. Addition to 810,274. Class 80(1). In a tensioning-device wherein a piston 5 and cylinder 3 are movable relatively to each other by a spring 7 to press a slipper 6 or other part against a chain or belt, return movement being prevented (except, if desired, for a limited amount) by oil or other liquid which enters the cylinder 3 from a reservoir 2 through a non- return valve comprising a resilient blade 10 located in the hollow piston 5, as in the parent Specification, the blade 10, Figs. 4, 5, is carried by a sleeve 11, or a transversely-curved part, which is fitted into the hollow piston and serves to retain the blade 10 in position. The necessity for riveting the blade 10 to the piston wall, as in the parent Specification, is thus avoided. As shown, the blade 10 is integral with a resilient sleeve 11 which is longitudinally split at 12 to grip the piston frictionally and has a small bent-out ear 14 which springs into a hole in the wall of the piston. If the sleeve is a tight fit in the piston, the ear 14 may be dispensed with. Alternatively other co-operating projections and holes may be provided between the sleeve and piston. The head 13 of the blade 10 is curved to fit over an oil inlet hole 8 in the piston wall, the hole 8 communicating with a hole in the bottom of the reservoir 2 by a passage which may be formed by a flat on the piston or by a groove in the underside of the reservoir. A small hole may be provided in the head 13 to allow slight return movement of the slipper 6. The arrangement shown, wherein the cylinder 3 is fixed and the slipper 6 is carried by the piston 5, may be modified as in the parent Specification so that the cylinder is movable and carries the slipper.