Patent GB-281746-A (GB)
Title: An automatic braking device, particularly for motor vehicles
IPC: B60T1/06
Filed: 1926-08-09
Abstract: 281,746. White, A. E., (Stewart-Warner Speedometer Corporation). Aug. 9, 1926. Brakes, arrangement and disposition of, and braking. - A brake having connections with a driving member or mechanism and with a. driven member or mechanism adapted to bring the brake into action when the speed of the driven member &c. exceeds the speed of the driving member &c., is provided with a torque controlling device for preventing a predetermined maximum torque being exceeded. The brake is applied by the motion of a driven member, or resistance to rotation of a portion of the brake, during rotation of the driven member in only one direction, the driven member being adapted to be driven in two directions by a driving member between which and the driven member are connections controlling the application of the brake and permitting its application when the speed of the driven member exceeds that of the driving member. As applied to the driving gear of a motor vehicle, a pinion 6, Fig. 2. driving the crown wheel 8 of the differential is carried by a short shaft 5 mounted in roller bearings in a casing 15 which encloses the braking mechanism and is screwed into the differential casing 14. The driving shaft 4 isconnected by a universal joint 26 to the flange 24 of a member 23 which rotates on a member 19 splined on the shaft 5, the member 23 being held on the member 19 bv the nut 22 which secures the member 19 to the shaft 5. The member 19, Fig. 5, is formed integrally with a drum 35 having internal longitudinal grooves 34 engaged by splines 33, Fig. 8, on a member 29, having internal left hand helical threads 28 engaging corresponding external threads on the member 23. When the shaft 5 over-runs the shaft 4 the member 29 moves forward against the action of springs 31. The drum 35 is formed with external righthanded helical threads 36 engaging internal grooves 37. Fig. 10, of a member 38 which is formed with external left-handed threads 41 engaging internal grooves in a member 43 to which one set of brake discs 45 are splined, the other set of discs 46 being splined to the casing 15. The member 38 normally abuts against a flange 30 on the member 29, but when the latter member moves forwardly the member 38 follows up and applies the brake through springs 39 arranged between the member 38 and a flange 43<a> on the disc carrying member 43. If the braking torque exceeds a predetermined value, the member 38 moves forwardly independently of the member 43 owing to the action of the helical threads 41 on the member 38 and corresponding grooves on the member 43. The brake is adjusted by a ring 49 screwed into the forward end of the casing 15 and bearing against the forward disc of the set 46, the ring 49 having internal teeth engaged by a pinion 52 operated through a universal joint 54 by a shaft extending forwardly and rotated by suitable gearing under the control of the driver. The sets of discs 45, 46 are of steel and cast iron respectively, and in order normally to separate the discs, the discs 45 are formed with spring tongues 79, Fig. 24. The brake is lubricated by oil passing from the differential casing through the space 71 around the shaft 5, the oil being thrown centrifugally through apertures 73 from whence it passes through the brake springs 39 and apertures 76 to the brake discs.