Patent GB-309401-A (GB)
IPC: H02K35/06
Filed: 1928-08-13
Abstract: 309,401. Wico Electric Co., (Assignees of Brown, P., and Louis, T. G.). April 9, 1928, [Convention date]. Inductor - alternators; reciprocating machines; casings.-The reciprocating armature of an ignition magneto is operated by means of a cam through a device comprising a spring which is compressed until the armature is forced away from the magnet poles through a non-elastic connection, when the spring expands, accelerating the armature; the stroke of the armature is then completed by the cam; at the same time operating the circuit breaker, arrangements are provided whereby the amount of compression of the spring may be varied. The armature 17 is mounted on a rock-shaft 87 which also carries a fixed arm 103 and two loosely journaled arms 101, 102 which can also slide longitudinally on the shaft. The arm 101 is actuated by a cam 94 on the driving-shaft 18<1>. When the parts are in the position shown in Fig. 6, a spring 116 separating the arms 101, 102 is compressed until the projections 114, 115 on the arms come into contact. The arms then move on together until the arm 102 comes into contact with a projection 119 on the arm 103 and moves the armature 17 away from the magnet poles. The attraction of the magnet on the armature being thus weakened, the spring 116 expands, accelerating the armature until the arm 102 comes into contact with a projection 117 on the arm 101. When the parts are in the position shown in Fig. 5 the arm 101 comes into contact with a projection 118 on the arm 103 before the spring 116 is fully compressed, so that the armature 17 is moved from the magnet poles earlier than in the former case and the action of the spring 116 is weaker. The arms 101, 102 are shifted along the shaft 87 by means of a rod 124 extending through the shaft and bearing on a pin 109 moving in a slot in the shaft. The rod 126 is operated by means of a lever 24 and cam 120 through a spring 123. The magnet consists of a number of bar-magnets 15 fitted to laminated pole-pieces 16. The whole fits into a block A of bakelite or the like, the laminations being secured by bolts 63, 64 and cross-bars 66 with flanges 67 secured to the top of the block A. The primary winding 19 and secondary winding 20 are carried on cylindrical bobbins 39 and are separated by cups 40. The limbs of the magnet are of square section so as to provide ventilating passages within the bobbins 39, leading into a cover plate C secured by blade springs 82 and having an opening protected by a second plate 80. The condenser is placed in a cylindrical bore in the block A and a second bore receives the circuit-breaker. This consists of a fixed contact 21 connected to the primary winding and a contact 22 carried on a rod 58 on which are blocks 59 of felt &c. which slides in the bore in the body A. The contactbraker is operated against the action of a spring 61, which also serves to ground the contact 22 on the hollow metal base B of the casing, by a cam 77 carried by the armature 17 and insulated therefrom. The base B contains a pad 136 soaked in lubricating oil which is conveyed to the bearings of the shafts 18<1> and 87 and the cam 94 by means of tubes 139, 140. Specification 283,400 is referred to.