Patent GB-452308-A (GB)
Title: Improvements in pedal operated controllers for electrically propelled vehicles
IPC: G05G13/00
Filed: 1935-03-12
Abstract: 452,308. Controlling electric vehicles. ENGLISH ELECTRIC CO., Ltd., 28, Kingsway, London, and MARDIS, P. L., WILSON, F., and CALDBECK, C. J., Phoenix Works, Bradford. March 12, 1935, No. 7671. [Class 79 (v)] [See also Group XXXVII] Means for controlling the motors and brakes of an electric vehicle, having a controller biassed to an "off" position situated between power and rheostatic braking positions, comprises a power pedal 6 to move the controller to its power positions, a brake pedal 2 for applying mechanical or fluid-pressure brakes, and yielding or lost-motion connections between the pedals and the controller allowing the brake pedal to be depressed to apply the brakes when the controller is held by the power pedal in its " off " position or in any power position and both to apply the brakes and to move the controller through all its braking positions if the power pedal is not depressed. In the construction shown the brake pedal 2 is connected by a link 1 and a lost-motion device 1<a>, 3<a> to one arm of a bellcrank 3 the other arm of which is connected to the controller (not shown). The power pedal 6 has an arm 6<a> connected by a link 5 to a lever 7 which may be, as shown, coaxial with the bell-crank 3 but is not connected thereto. When the power pedal is depressed an adjustable stop 8 on the lever 7 acts on the bell-crank 3 and operates the controller. In the position shown in Fig. 1, both pedals are released and the controller and the bellcrank 3 are in the "off position. When the brake pedal 2 is depressed it preferably first applies the brakes and takes up part of the lost-motion at 1<a>, 3<a> as shown in Fig. 2. Further movement of the brake pedal takes up the rest of the lost-motion and finally rocks the bell-crank 3 clockwise for rheostatic braking. When the power pedal 6 is in the released position shown the gap between the stop 8 and the bell-crank 3 is sufficient to allow the controller to be moved to its braking positions without affecting the pedal 6. If the power pedal is depressed to rotate the controller to any of its power positions there is sufficient lost-motion at 1<a>, 3a to allow the brake pedal to apply the brakes without interfering with the power pedal, but the power is cut off in that case by a switch (not shown), operated by the brake pedal. As applied to fluid-pressure brakes a brake valve 12 biassed to the braking position is normally held in the " off " position by means of an arm 11, link 10, and a loose arm 9 having an adjustable stop 9a bearing against an abutment 2b on the lower arm 2a of the brake pedal 2. Thus, when the brake pedal is depressed the abutment 2b moves away from the stop 9<a> and allows the valve 12 to move to its braking position. In a modification the collar 1<a> on the link 1 may be moved back and a spring provided between the collar and the bell-crank 3 so that the first movement of the brake pedal compresses this spring and moves the controller, if it is in its " off " position, to the braking positions. The mechanical or fluid-pressure brakes may be applied simultaneously with or later than the electric braking, the brake pedal acting on the arm 9 at any desired portion of its stroke so as to move the brake valve 12 to its braking position. The spring on the link 1 may be used as the biassing spring returning the controller to its " off position.