GB1458581A - Spring-force applying devices - Google Patents

Abstract

1458581 Spring-applied; fluid-pressure released brakes SVENSKA AB BROMSREGULATOR 17 Dec 1974 [2 Jan 1974] 00043/74 Heading F2F In a vehicle spring brake actuator or other spring-force applying device comprising a spring 5 acting between two members 1, 2 one of which may be coupled by a clutch to a force transmitting element 15 and both of which define a chamber 4 for pressure fluid for relieving the element 15 of the spring load, the clutch is disengageable by a rotary manual member 126 which is accessible from outside, but is not axially movable of, the device. The clutch comprises a series of balls 115 disposed in an annular space defined by an internal groove 124 of a tubular extension 103 of the piston 2, an end of an extension 105 of the element 15, a ring 118 urged by a spring 116 and the exterior of a stepped extension 110 of an axial member 106 which is urged outwardly by a spring 109. From the inactive condition shown with the chamber 4 expanded, on release of the pressure fluid the spring force is transmitted through the clutch to the element 15 to an arm 28 and brake rigging. To disengage the clutch an end 126<SP>1</SP> is rotated clockwise, rotating the member 106 by means of a key 10611, when a radial pin 125 causes the member 106 to move axially together with its extension 110 so that the balls 115 may move inwards to the reduced diameter portion of the extension.