GB848806A - Brake control system - Google Patents

Abstract

848,806. Controlling vehicles. SAFETY AUTOMATIC BRAKE CORPORATION. March 31, 1958, No. 10298/58. Class 79(5). [Also in Group XXXIV] In a motor vehicle the accelerator pedal 40, Fig. 1, has a lost motion connection with the throttle 3 and is connected by a rigid linkage with a brake control valve 20 so that as the pedal is depressed the brakes are gradually released before the lost motion is fully taken up and the throttle begins to open. The pedal is pivoted at 41 and connected by links 42, 43, 44 with an actuating lever 97 on the valve 20, a bracket 44b secured to the link 44 and a pair of stops 45x on a link 45 forming the lost motion connection to the throttle. When the vehicle is standing still and the engine idling, suction in the engine manifold 2 is transmitted through a pipe 21 to a chamber 55 in the valve 20 and through pipes 22 and 23 to booster cylinders 15 and 16. The cylinder 15 applies the service brakes 5..8 through a linkage 17, 18, a master cylinder 14 and hydraulic connections 12, 13 while the cylinder 16 releases emergency brakes through a pull rod 39, a lever 33 and cables 30-30. A hand lever 35 for operating the emergency brakes is connected to the lever 33 by a cable 36 and a spring 37 which permits the cylinder 16 to release the emergency brakes even when they have been applied by hand. To start the vehicle moving, the pedal 40 is depressed to rotate the lever 97 and a cam 95, Fig. 3, secured thereto, the cam follower 93 and a slide 82 being displaced to the left to reduce the pressure applied by a spring 87 to a diaphragm 54. The latter is pulled to the left by the suction in the chamber 55 so that a valve 76 is closed by a spring 77 to trap the vacuum in the cylinder 16 while a valve 68 isolates the chamber 55 from the suction in the pipe 21. Air entering through a filter 50, slide 82, a port 66<SP>1</SP>, and the space between the valve 68 and its seat 67, enters the pipe 22 through a hole p in a valve 79 to release the service brakes gradually. Loss of fluid from the cylinder 14 causes an arm 125 to depress a valve 120, Fig. 6, and admit air through ports 118 and 119 to the cylinder 16 so that the emergency brakes are applied by the spring 37. Simultaneous closure of a port 124 prevents loss of vacuum in the chamber 55. The pedal 40 may be held in any set position by a pawl 133 and a toothed wheel 130 which are brought into engagement when a solenoid 132 is energized by closure of a switch on the instrument panel of the vehicle. Closure of the horn circuit may be arranged to energize a second solenoid whose core strikes that of the first solenoid to release the pedal 40 in an emergency. In a modified construction the booster cylinder 15 and the master cylinder 14 are coaxial and form a unit to which the valve 120 is secured. The latter is of modified construction and includes a lost-motion connection to seal the chamber 55 before the cylinder 16 is opened to atmosphere.