Patent GB-197299-A (GB)
Title: Improvements in or relating to brakes for vehicles
IPC: B60T8/52
Filed: 1923-03-06
Abstract: 197,299. Hallot, P. May 6, 1922, [Convention date]. Void [Published under Sect. 91 of the Act]. Operating clutches.-Relates to vehicle brake mechanism of the kind in which the brake application force is wholly or in part derived from or controlled by a drum adapted to be clutched to a running axle or shaft of the vehicle by centrifugally controlled masses. The Specification describes: (a) means whereby the force applied to the pedal or equivalent is transmitted directly to the brakes and when the force exceeds a predetermined value the centrifugal clutch device also becomes operative ; (b) centrifugal clutch devices driven by friction or other gearing in combination with winding gear for applying the brakes; (c) continuous cable or like means for simultaneously bringing the centrifugal clutch devices on a number of vehicles into operation to apply the brakes. (a) As shown in Fig. 2 the rod 1 connected for example to brakes on the front and rear wheels of a motor vehicle is attached to rods 4, 5, and connected respectively to the brake operating pedal and to the end of a friction band 6. the rod 4 having an interposed spring 17. The other end of the band 6 is connected by a lever 8 pivoted at 9 to the rod 4. The centrifugal clutch device shown comprises a drum 16 keyed for example to the driving shaft of the vehicle and having recesses in which are disposed masses 12 adapted to be urged into contact with the drum or pulley 7 by centrifugal force and also to a limited extent by springs 14. When force is applied to the rod 4 this rod and the rods 1, 5 move together until the brakes are applied, the band 6 is therefore not tightened at this stage. If, however, the pull on the rod 4 is sufficient to overcome the spring 17, this rod by its further movement tightens the band 6 by the lever 8 and additional force is applied to the brakes by the centrifugal clutch device acting through this band. If the wheels tend to scotch the force applied by the centrifugal device is reduced to that due to the springs 14. The initial compression of the spring 17 may be adjusted by a nut and a scale. To indicate when the centrifugal device has been brought into operation, a tappet may be provided on the rod 4 adapted to engage a gong sounding or indicating needle device. An electrically controlled indicating device may also be arranged to be operated when the cylinder of the spring device which is fixed to the rod 1 reaches a given position. Arrangements are also shown in which an internal band and internal segments adapted to engage the drum 7 are substituted for the external band 6. The plate which carries the pivot of the segments and also that of the operating cam is shown as adapted to be turned about the central shaft by the rod 5 to which it is connected while the cam lever is connected to the rod 4. (b) Fig. 11 shows a centrifugal clutch device 37 adapted to be engaged by friction or other gearing with the drum 38 on the shaft of a wheel and combined with a windlass adapted to drive a drum 41 provided with a cam 42 upon which is wound a member 43 connected to the brake-blocks. By means of the cam the blocks are rapidly engaged with the wheels and a high mechanical advantage obtains when the blocks are engaged. Fig. 14 shows a centrifugal device E' arranged to drive a windlass D<1> the shaft C' being carried by oscillating supports 61 whereby a friction wheel A' may be engaged with the vehicle wheel B' by the rod 60 of a brake piston when it is desired to drive the device E<1> and thus apply the brakes. The windlass, the vehicle wheel and the lever to which the cable of the windlass is connected may be so arranged that the pull on the cable when the brakes are applied may act to increase the pressure by which the friction wheel is applied to the vehicle wheel. (c) The friction wheel shown in Fig. 17, of the centrifugal device is adapted to be applied to the vehicle wheel by the weighted lever 48 which is normally held raised by a continuous chain or cable 53 passing around a pulley 50 on the lever and extending to a controlling windlass 54 which may be operated directly by hand or by the rotation of the axle. The brakes are also applied if the couplings break and in shunting operations.