Patent GB-648958-A (GB)
Title: Improvements in ignition systems for engines
IPC: F02P15/00
Filed: 1946-07-10
Abstract: 648,958. Ignition systems. BENDIX AVIATION CORPORATION. July 10, 1946, No. 20653. Convention date, Aug. 29, 1945. [Class 7(iv)] [Also in Group XXXVII] In remote control means comprising a source of electrical energy such as battery 41, one terminal of which is connected to a power line c and the other is connected to earth, a plurality of relay mechanisms 11, 66 each consisting of an armature 26 operating a relay switch 22, 24, a pair of electromagnets 27, 28, adapted to be alternately energized by the source for actuating the armature, one terminal of one magnet of each pair being connected to the power line and one terminal of the other magnet of each pair being earthed, and an auxiliary change-over switch 42-44, controlled by the armature and comprising separate contacts electrically connected to the other terminal of each of the magnets and a common terminal alternately engageable by the separate contacts to alternately close a connection to one of the magnets 27, 28, while breaking a connection to the other magnet, there is provided coordinated selection switches 10 for the relay mechanisms for selectively connecting the common terminals of the switches 42-44 simultaneously to the power line c or to earth or some terminals to earth and others to the power line. The apparatus is described in connection with the ignition system of a four-engine aircraft, each engine of which is equipped with seven dual-type magnetos each having two coils and each coil energizing one bank of spark plugs of one row of a multi-row engine. The primary winding 15 of the circuits for the left-hand bank of plugs of one engine is permanently earthed at 21 on one side, whilst the other side may be earthed through a lead 12 and the relay 11. Contact 44 is connected to the terminal 50 of the switch 10, which terminal may be connected to any one of four contacts O, R, B or L by a lever 51, but under normal operating conditions the contacts B and L are earthed through a line e and two emergency switches 60 and 61, operation of which latter stops all the engines: contacts Rand O are connected to bus-bar c. The energization of coil 27 by moving arm 51 on to contact R and consequent clockwise rotation of armature 26 effects the earthing of the other side of coil 15 thereby preventing operation of the ignition system. The connection to earth at switch 61 of one side of coil 28 by moving lever 51 on to contact L, causes anti-clockwise rotation of the armature 23 and hence renders the ignition systems operative. Power is only taken by the coils during the actual period of movement of armature 26. In order to control the right-hand bank of plugs of one engine, relay 66, identical with relay 11 and a lever 65 identical with lever 51 are provided. The levers 51 and 65, when mechanically connected, can arrange for either one or both banks of plugs to function or be inoperative as required depending upon whether the levers move on to contact O or B, respectively. Three other pairs of levers 51, 65 are used to control, through similar relays 11 and 66, the ignition circuits of the other three engines. Specification 614,340, [Group XXXVII], is referred to. The Specification as open to inspection under Sect. 91 states that booster current may be supplied through lines 71. This subject-matter does not appear in the Specification as accepted.