Patent GB-267577-A (GB)
Title: Improvements relating to brake or other mechanism operated from the suction obtainable from the induction system of internal combustion engines
IPC: B60T13/48
Filed: 1925-11-13
Abstract: 267,577. Kennington, W. O. Nov. 13, 1925. Fluid-pressure; hand, foot, and personal actuation. - Consists in means for controlling the degree of suction applied to a pneumatic con. trivance from the induction system of an internalcombustion engine, in which a control space, in permanent communication with said contrivanceis provided with a pair of ports associated with one or more control valves, the ports serving to control entry and exit of combustible into and from the control space. The control space h, Fig. 2, may be the space comprised between twc throttle valves 2, 3 arranged in series in the passage 5 leading from the carburettor. The space is connected at 6 to the pneumatic device and the throttles, when in the normally closed positions, leave small openings at 7, 8 thus ensuring a sufficient flow of mixture for the slow running of the engine. During normal running the valve 2 is kept fully open, the engine being controlled by the valve 3. To apply the brakes the valves 2 and 3 are both closed and then valve 3 is opened to transmit suction in a progressively increasing degree to the space h and the pneumatic device. To release the brakes, valve 3 is closed and valve 2 is opened fully thus admit.- ting combustible mixture at atmospheric pressure to the pneumatic device. In a modification, the control space is in a by-pass to the induction pipe. Thus a casting a, Fig. 4, is bored to form the control space h which receives a sleeve b provided with diametrically opposite ports n, o of the shapes shown in Figs. 5, 6 these ports controlling ducts k, m. The duct j is connected to the pneumatic device, and the ducts k, m to the induction pipe on the engine and carburettor sides respectively of the throttle valve. The sleeve b is loaded by a spring f. is prevented from rotating by a washer p and flat face e, and is actuated by the foot through a pad d. To apply the brakes, the throttle valve is closed and sufficient mixture for slow running is supplied through duct m, large part of port o, port n, and duct k. The pad is now depressed so that duct m is restricted and duct k more fully opened to transmit suction to the duct i and the pneumatic device. To release the brakes it is only necessary to release the sleeve b. In place of one sleeve, two separate ported sleeves may be employed. In either of the above cases an auxiliary connection to the pneumatic device may be provided to apply suction to the release side to keep the brakes " off " prior to the admission to that side of combustible mixture to apnlv the brakes. Two constructions are described showing the application of the auxiliary connection to the forms of apparatus shown in Figs. 2 and 4. In lieu of the auxiliary communication, the release side may be connected to the engine crank casing so that a certain amount of oil mist may enter to act as a lubricant. A normal brake pedal may be coupled through a lost-motion device to the mechanism for actuating the suction-controlling valves, thus enabling the application of the brakes to be augmented by the foot, or to be effected if the suction system fails. Such an arrangement is shown in Fig. 10, in which the pneumatic cylinder 13 is connected by pipe 19 to a device h, as shown in Fig. 4, connected by pipes 20, 21 to opposite sides of the throttle 23. Brake rods 24, 25 are attached to an equalizer bar 26 connected through a link 27 to a bent lever 19 connected at one end to the sleeve b and at the other end to the pedal 18. A stiff spring 31 is also inserted between lever 29 and pedal 18, The suction side of the cylinder 13 is connected to the crank case by a pipe 16, and the piston is connected through a 'rod 33, sector 31a, and chain 32 to the bar 26. To apply the brakes, the throttle is closed and pedal 18 depressed and the bar 26 drawn forward. The spring 31, is then extended and lever 29 is rocked to withdraw sleeve b and apply engine suction to cylinder 13. If the engine is not working the brakes may be applied by foot pressure alone. Specification 228,225 is referred to.