GB1036690A - Improvements in or relating to mechanical actuating means for emergency operation ofan air brake system - Google Patents

Abstract

1,036,690. Compressed-air brakes. NEWAY EQUIPMENT CO. June 25, 1965, No. 26947/65. Headings F2E and F2F. An emergency mechanical actuator for compressed-air braking systems of heavy road vehicles, e.g. tractor/trailers, comprises, in addition to the usual air motor 10, a spring- operated unit A adapted to be held in the inoperative position shown by compressed air acting on a diaphragm 29a and supplied via line 24 from the reservoir 13 which feeds, via the usual driver's valve 48, the motor 10, there being provided also a lever 14 which is freely pivoted on a brake-actuating shaft 17, e.g. a cam-shaft, to which is secured a brake arm 15, the lever being connected at 38 to a rod 32 operated by the diaphragm 29 of the motor 10, while the brake arm, which has a face 20 normally engaging part of the lever 14, is connected by a cable 25 with piston 22 of the spring-operated unit. The arrangement is such that in normal service operation, with springs 21 of unit A compressed, the lever 14 and brake arm 15 are rocked as a unit by operation of motor 10, the brake release springs (not shown), and a spring 47, maintaining the lever 14 and arm 15 in engagement, and the sheath 49 of the cable 25, which abuts a thrust member 57 on a bifurcated portion 18 of the lever 14, flexing as shown by the dash-dot lines. Should air pressure fail, however, causing springs 21 to urge piston 22 to the right, the cable 25 is able to rock the brake arm 15 independently of the lever 14 to an extent exceeding the normal travel. Should it be desired to release the brakes thus applied before air pressure is restored a pin 61, which together with a pin 62 detachably secured a cable clip 59 to the arm 15, is removed so that the clip may pivot and thus slacken the cable. The lever 14 is journalled on a worm-wheel 41 secured to shaft 17 and which is engaged by a worm 44 disposed within the bifurcated part of lever 14 and journalled in the arm 15, for rotation by a hand tool which is adapted to be engaged with a suitably formed end 45 of the worm shaft, to enable adjustment of the angular position of the lever relative to the shaft.