GB351908A - Improvement in motor controlling apparatus - Google Patents

Abstract

351,908. Master control of motors ; controllers. SULLIVAN MACHINERY CO.; 400, North Michigan Avenue, Chicago, U.S.A. Dec. 23, 1929, No. 39301. Convention date, Jan. 2. Void [Published under Sect. 91 of the Acts]. [Class 38 (iii).] With auxiliary switches; locking electromagnetically.-A pilot switch for a contactor starting system for a motor, and a motor reversing switch are combined in a single unit in such a way that although the former may be operated at will, the latter cannot be opened until the motor is substantially at rest. An operating shaft 9, Fig. 2, is connected by gearing to a toothed movable element 15, upon which are mounted contacts 18, 19 which slide over stationary contacts 54, 55, 58, 59, Fig. 4. A number of the teeth 30 on the periphery of the member 15 are reduced in length to form a recess 53 on which the arm 49 of the pilot switch rests, closure of this switch being effected by rotating element 15 to bring full length teeth into connection with the switch arm 49. When the pilot switch is closed by placing the reverse switch in one or other of its extreme positions the first contactor 68, Fig. 7, is closed and also a switch 72. This closes the next contactor 69 and short circuits the first section of the starting resistance 77. Similarly contactors 70, 71 are closed in turn and the motor is placed directly across the supply. With the reverse switch in one of its extreme positions a coil 40 connected across the motor armature is energized and a plunger 39, Fig. 2, rests in one of two recesses 37, 38 in the member 15. Owing to the length of these recesses, the reverse switch can be moved the small amount necessary to open the pilot switch, but it cannot be moved to open its own contacts, until the motor comes to rest. The operating shaft 9 is moved by a handle so attached to it that the reversing switch cannot be rotated beyond the central position without pausing to slide the handle along the shaft. Specification 243,964, [Class 79 (v), Motor vehicles, Steering &c.], is referred to.