GB840986A - Improvements in or relating to steering control mechanisms of crawler-tracked vehicles - Google Patents

Abstract

840,986. Steering vehicles by declutching and braking. AVELING-BARFORD Ltd. June 17, 1958 [June 20, 1957], No. 19434/57. Class 79(2). A crawler-tracked vehicle, such as a crane or excavator, has two tracks 1, 2 connected with a power source through clutches 12 which may be alternatively disengaged by manually-controlled reversing gear driven by a torque limiting device 34 from a continuously rotating shaft 33. The clutches 12 are slidably splined on sleeves 7, 8 fast with an axle 9 driven by gearing 27, 28, 30 and 32 from the power unit of the vehicle and have holes or recesses to engage dogs 11 on a brake drum 10 fast with a sprocket for driving the corresponding-track. Each drum 10 is surrounded by a brake band 23 which is anchored at one end to a bell crank lever provided with screw adjusting means and at its other end to a bell crank lever 26. The latter is connected by a further bell crank lever 55 and a ball-and-socket to a fork 21 in engagement with a groove 22 in the clutch 12. The two forks are slidably mounted on a rod 57, Fig. 2 (not shown) biased apart by a spring 58 and connected by chains 54 to a bracket 53 extending radially from the bottom of a shaft 51. Gearing 47..50, band gears 39..41, a shaft 38, a chain 36 and the device 34, in the form of a slipping clutch, connect the shaft 51 to the shaft 33. A manually-operated clutch 43 may be moved to either side of the neutral position shown to engage one or other of the bevel gears 39, 40 with the shaft 38 to cause angular displacement of the bracket 53 in the desired direction to declutch and brake one of the tracks.