Patent GB-503263-A (GB)
Abstract: 503,263. Engine stop-gear. MANNHEIMER, G. Dec. 29, 1937, Nos. 36035 and 36036. Convention dates, Jan. 30 and Dec. 13. [Class 122 (iv)] In stop - gear for internal - combustion engines a fluid-pressure controlled operating device controls an electric circuit so that this circuit is operative when the pressure is more than a predetermined value. A timing device holds the circuit operative for a fixed time period, an auxiliary device automatically rendering the circuit operative and actuating the primary device. The diaphragm 5, Fig. 1, is subject to lubricating oil pressure. The solenoid 7 is connected to an electrical starting device 9. A soft iron core 10 therein is connected through insulation to the diaphragm 5 and by wires 13, 15 to the ignition switch 16 which in closed position connects the negative pole of the battery to the ignition device 30. The core 10 carries a contact 17 which engages a spring-pressed control 18 in an armature sleeve 20. The armature is carried by a spring 25 connected to the device 30, carries an insulation ring 22, and has a recess 24 which is engaged by a projection 27 on a bimetallic or thermostat member 26. When the switch 16 is closed on starting the engine, the piece 17 is connected to the battery. When the pedal 9 is operated, a current through the solenoid causes the armature 20 to move down, the projection 27 engages the notch 24, and a current passes through contacts 17, 18, recess 24 and heating-winding 28, and also to the device 30. The starting device 9 having ceased, if the oil pressure has built up sufficiently, contact between the parts 17, 18 is maintained upon release of th& notch 24. If the pressure 'is inadequate, upon the release of the notch, the contacts 17, 18 separate and the engine stops. A modification is described, applied to an ignition coil, wherein the spring 25 is connected with a number of accessories, e.g. petrol gauge &c., and with one end of the primary wire of an ignition coil the other end of which is earthed by a wire and a cam operated make-and-break contact. Upon stoppage of the oil supply, the primary circuit is interrupted. In a further modification of this construction, the armature 20 is coupled mechanically to the starting pedal. In the arrangement shown in Fig. 3, applied to magneto control, the membrane 47 carries a flanged rod 48 depressed by a spring 50. An armature 51 is slidably arranged on the rod 48 and co-operates with a sleeve 52 carrying an insulating-ring 53 co-operating with a contact 64 connected to a heating-winding 56. A contact arm 57 is mounted above the rod or an insulated pin 58 connected to the magneto 61. The opposite end of the arm has an insulated contact piece 62 connected to the primary circuit of the ignition coil. The contact 62 engages a contact 64 connected to the heating-coil 56. When the starting-contact and starting-device are operated, the armature 51 is raised, the contact 54 snaps under the enlargement on the sleeve 52, and the contacts 62, 64 engage. A current passes through the heating-winding 56 and the primary wire of the ignition coil and the apparatus in parallel therewith. If after the lapse of a certain time the oil pressure is insufficient, the contact 54 is pulled out, contacts 62, 64 are opened, the primary circuit is interrupted and the magneto earthed. A further modification is described wherein a diaphragm operates on a three-contact lever under the control of a hand or mechanicallyoperated press button which acts through a longitudinally-movable element which is locked by a bimetal, temperature-controlled detent. When the button is pressed, the primary ignition coil and auxiliary apparatus are started and a starting-relay and heating-coil current are switched in. When the detent is withdrawn, the lever returns and breaks the con- 'tacts unless the oil-pressure has satisfactorily risen. A construction is described wherein the primary coil is provided with a series resistance which is provided with two shortcircuiting terminals actuated by the bimetal member. The resistance is normally in circuit. In an arrangement applied to a Diesel engine, a rod controlling the pump is made in two parts held together by a solenoid supplied with current from the contact arm 25, Fig. 1. So long as the current flows the pump functions. Should the lubricating pressure fail to rise or cease, the parts of the rod separate and the pump stops.