Patent GB-451579-A (GB)
Title: An improved method of and means for effecting economy in the running of motor vehicles
IPC: F02B77/08
Filed: 1934-12-07
Abstract: 451,579. Controlling motor vehicles ; electric switches. GUY, S. S., Sauchieleigh, Albrighton, Wolverhampton. Dec. 7, 1934, No. 35141. [Class 79 (v)] [See also Group XXXYII] A delayed-action device is provided in connection with the steering wheel or the hand brake of a motor vehicle, so that when the brake is applied or the steering wheel is released, the engine is automatically stopped after the expiration of the time interval determined by the delayed-action device. In the construction shown in Figs. 2 and 3, a switch d, comprising a slidable insulated rod d<1> with a conducting ring d<2> co-operating with spring contacts d<3>, is inserted in the circuit of an electromagnet e and is normally closed when the hand-brake is " off " by means of a Bowden wire c connected to the brake hand lever (not shown). The armature g of the magnet completes the ignition circuit. When the brake is applied, the wire c is released and a spring d<4> opens the switch so that the magnet circuit is broken and the armature g opens the ignition circuit after a time lag depending on the strength of a spring g<1> and the residual magnetism of the magnet. In the construction shown in Figs. 4 and 5, the steering hand wheel b contains a switch comprising a contact ring b<1> in the wheel, a movable contact ring b<2> and spring b<3>, this switch being inserted in the ignition circuit and being normally closed by the grip of the driver on the wheel. When the driver releases the wheel the switch is opened, but the ignition circuit is still completed through a shunt comprising a thermostatic switch i with a heating coil i<1>. After a predetermined time interval the switch i is opened due to the heating of the coil and the ignition circuit is broken until the driver again closes the steering wheel switch. In the construction shown in Fig. 6, the switch is combined with a dashpot and comprises a cylinder m with contact strips m<1>, m<2>, adapted to be bridged by an insulated contact ring l fixed to a plunger j controlled by a spring n and a cable c. When the hand-brake is " off " the cable c is pulled and the ring l completes the ignition circuit. When the brake is applied the cable c is released and the spring n breaks the ignition circuit by returning the plunger and the ring l to the top of the cylinder at a rate determined by the size of the air outlet o. Alternatively, the application of the hand brake may tension a spring connected to the plunger j, so that the plunger moves slowly under the influence of this spring to break the ignition circuit. In a modification, a straight or circular rack adapted either to make and break the ignition circuit or to open and close a valve in the engine fuel or air supply pipe is controlled by a spring or weight wound up by the action of releasing the brake. When the brake is applied a pawl is released to free the rack which then moves under the influence of the spring or weight at a rate controlled by an escapement, so that the ignition circuit is broken or the fuel supply cut off at a predetermined time interval.