GB307831A - - Google Patents

Abstract

307,831. Bragg-Kliesrath Corporation, (Assignees of Sorensen, J.). March 14, 1928, [Convention date]. Fluidpressure.-Power brake mechanism for vehicles comprises a valve controlled actuator or cylinder, a power applying member or lever pivoted at a fixed point and connected to the actuator, a second lever or member pivoted to the power applying member and connected to the brakes and means for applying the physical force of the operator to the second member whereby this force reacts on a connection of the second member to the brakes to operate the power actuator through the valve mechanism. The arrangement is such that the pressure applied by the power actuator reacts upon the foot of the operator, the valve mechanism has a follow-up action and the operator can apply a direct effort to the brakes. The power applying lever 28 mounted on a fixed pivot 29 is connected by a cable &c. 27 to the piston of the brake cylinder or actuator and has secured to its upper end the valve casing 39. The lever is of channel section and has pivoted within it at 36 a lever 35 which is connected to the brakes by the link 38 pivoted at 37. An extension 59 of the valve rod 49 abuts on the lever 35. The valve rod also carries a pedal plate 55. The valve casing has connections 44, 45 and an aperture 47 leading respectively to the suction pipe of the vehicle engine, to the brake cylinder and to the atmosphere. The valve casing 39 extends through the vehicle dashboard. Fig. 3 shows the parts in the normal position in which the brake cylinder is connected to atmosphere through the aperture 47. If the pedal 55 is depressed and the brake piston is adjacent its stop, the lever 28 remains stationary and the lever 35 turns upon the pivot 36 and starts the application of the brakes through the link 38; the valve 53 then covers the aperture 47 and the valve 54 uncovers the aperture 44 as in Fig. 4 thus connecting the brake cylinder with the engine suction pipe whereby power is applied by the piston to the brakes through the lever 28, pivot 36 and link 38. If the movement of the pedal is stopped the continued movement of the lever 28 moves the valve casing sufficiently to re-close the aperture 44 and the brakes are held applied. The pressure felt by the operator indicates the pressure that is being applied to the brakes. The pedal may be depressed sufficiently to cause a boss 55<a> to contact with the valve casing and thus enable the operator to add his direct effort to the full power of the piston. If in starting an application of the brakes, the brake piston is not against its stop or if it takes less pressure to move the piston towards its stop than it does to overcome the resistance of the brakes, the lever 28 will be moved and power will be immediately applied by the brake piston to the brakes.