GB587033A - Improvements in and relating to band brakes and actuating means therefor - Google Patents

Abstract

587,033. Brakes. SELF-CHANGING GEAR CO., Ltd., WILSON, A. G., and MILLER, A. A. March 13, 1944, No. 4655. [Class 103 (i)] Substantially semi-circular brake-shoes 3, 4 are located between the band 2 and the drum 1, the shoe 3 being fixed to the band whilst the shoe 4 is loosely secured to the band and is provided with a lug 5 extending through a slot in the band for attachment to links 5b pivoted to a fixed member 5c. Alternatively, a pair of lugs 5, one on each side of the band, are provided. The shoe 4 is loosely secured to the band 2 by studs 4b having flattened portions accommodated in slots 4c which permit the shoe to slide circumferentially relatively to the band. The shoe 4 may, instead, be secured to the band by a pin or pins passing through a slot or slots in the band, the outer end of the pin being secured to a leaf or other spring bearing on the back of the band. The band is formed at 7, 8 with pairs of spaced cheeks between which are confined compression springs 7b housed in bores in the ends of levers 7a, 8a. The springs may bear directly on the cheeks or piston-like caps may be interposed, the arrangement being such that the band is frictionally constrained, when released, to open concentrically of the drum. The levers 7a, 8a have tails 7d, 8b engageable with stops to limit the swing of the levers. The fluidoperated piston 9 for applying the brake pressure to the end 2b of the band is recessed to receive a split ring 9d, the ring having axial play in the recess. The ring 9d is located in the cylinder by the outward movement of the piston, but it has sufficient friction with the cylinder wall to act as a stop for the piston, on its return stroke, thereby limiting the extent to which the resilience of the band 2 can retract the brake shoes This stop means forms the subject-matter of Specification 587,068. The end 2c of the band is anchored by link 11 pivoted on the cylinder cover lOb.