GB744573A - Improvements relating to apparatus for arresting vehicles such as mine cars, tubs orthe like - Google Patents

Abstract

744,573. Railway stops. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd., and HARRIS, M. R. Oct. 29, 1954 [Dec. 8, 1953], No. 34109/53. Class 104 (2). In an apparatus for stopping mine cars, tubs or the like by an axle or wheel engaging resilient means the stiffness of the resilient means absorbing the shock is less for empty or lightly loaded vehicles than for heavily loaded vehicles. A stop member 6, pivotally mounted about a pin 10 on a frame 12, is raised or lowered by a pneumatic device 11 pressing a roller 9, through a link 15 and arms 17, 19 attached to a shaft 18, against the underside of the member 6. The control of compressed air to the device 11 is effected by manual operation. The stop member is of telescopic construction and has an outer member 28 and a hollow sleeve 2 closed at one end by a head 3. Within the stop 6 an abutment 25 formed with a forwardly facing projection 26, separates a light spring 27 and a heavy spring 22. When a lightly loaded vehicle wheel or axle strikes the head 3 the spring 27 only is compressed but with a heavily-loaded vehicle the spring 27 is compressed until the projection 26 abuts the head 3 and the load is then passed onto the spring 22. A plug .23 screwed into the member 28 extends into a slot 24 in the sleeve 2 limits the outward movement thereof. The sleeve 2 has a key 4 which engages a slot 5 in the member 28 and when in the inoperative position between the rail ends 1a, 1b the upperside of the member 28, the key 4 and the head 3 form a running surface for the vehicle wheels. In an alternative arrangement a light spring is arranged around the outside of and is slightly longer than the heavy spring so that the light spring is initially compressed and later the heavy spring. In further modifications a conical or a volute spring is used so that as the load increases the resistance of the spring increases.