Patent GB-359264-A (GB)
Title: An improved device for automatically preventing the locking and slipping of vehicle wheels when braking
IPC: B61H7/02
Filed: 1930-11-26
Abstract: 359,264. Vehicle brakes. COMPAGNIE INTERNATIONALE DES FREINS AUTOMATIQUES, SOC. ANON., 70, Rue Louvrex, LiÞge, Belgium. Nov. 26, 1930, No. 35655. Convention date, Nov. 26, 1929. [Class 103 (i).] In a device for preventing the locking and skidding of the wheels of a vehicle when the brakes are applied, a block which is spring-pressed against the track or a wheel is arranged to release the brakes and also to operate a sanding apparatus, if desired, if the frictional drag on the. block due to fall of the coefficient of friction between it and the track, or wheel becomes reduced to a predetermined value. In another arrangement the control is effected by the slipping of an auxiliary wheel to a drum on which spring-pressed blocks are applied. A block 4, Fig. 1, arranged to be forced against the track rail 5 by a spring 9 is connected to a lever 7 controlling contacts 12, 13, 14. Springs 8 tend to hold the lever in the position shown in which the contacts 12, 13 are connected. In the normal position shown of the main controller S, contacts 24, 25 are bridged so that the circuit of a magnet 10 is completed to raise the block 4. If the controller is moved to the position F to apply the brakes, the magnet 10 is de-energized so that the block 4 is applied to the track by the spring 9 and the frictional drag on the block is normally sufficient to move the lever 7 to the position in which the contacts 12, 14 are bridged. The circuit of the braking magnet 19 is thus closed from the battery B through the contacts 12, 14 and the controller contacts 17, 18. If however on account of a fall in the value of the coefficient of friction between the block 4 and the rail, the spring 8 is able to return the block and the lover 7 to the position shown, the circuit of the magnet 19 is broken and that of the brake releasing magnet 15 is closed through the contacts 12, 13. The circuit of the magnet 21 of a sanding apparatus is also completed through the contacts 12, 13 and the controller contacts 32, 23, The brakes are automatically re-applied when the friction reaches the normal value. The contacts 22, 23 may be so arranged that the sanding apparatus comes into action before the braking position of the controller is reached. In the third position of the controller S the release magnet 15 is energized through contacts 16, 20. In the arrangement shown in Fig. 2, a pair of blocks 39 forced by a spring 41 against a drum 38 on a wheel 37 which is not braked by the vehicle brakes are attached by rods 40 to a lever 42..As long as the adhesion or coefficient of friction between the wheel 37 and the rail is above a predetermined value, the lever 42 is turned by the drag of the blocks 39 against the pressure of one or other of the springs 34, 35 so as to bridge the contacts 12, 14 or 14<1> and enable the main controller to complete the circuit through the application magnet 19. If however the wheel 37 tends to skid the lever 42 is returned to the position shown by the springs and the circuit of the release and sanding magnets 15, 21 is completed through the contacts 12, 13. A pair of blocks 4 or wheels 37 coupled together may be provided one for each rail.