Patent GB-190403886-A (GB)
Title: Improvements in Electric Motor Control Systems
Filed: 1904-02-16
Granted: 1905-02-09
Abstract: 3886. British Thomson-Houston Co., [General Electric Co.]. Feb. 16. Motors, controlling. - Relates to a series-parallel system of control, especially designed for use on electrically - propelled vehicles, in which the electromagnetic switches for varying the series and parallel connections of the motors, and for regulating the resistance in the motor circuits, are normally kept under strain tending to close them, and are successively closed in any predetermined order by the rotation of a cam shaft. Fig. 1 shows the preferred arrangement of parts, and Figs. 2, 4, 5, and 6 show a construction of controller, in which the operating-mechanism is slightly modified. The invention is also described in its application to a multiple-unit system of train control. The controlling-apparatus shown in Fig. 1 comprises master-controllers C<1>, C<2>, a master-reversing switch R<1>S<1>, an electromagnetic reversing- switch RS for the motors M<1>, M<2>, and a motor controller C, adapted to control the series and parallel positions of the motors and to vary the sections of the resistance r in the motor circuit. The controller C consists of a rotary shaft A, to which are yieldingly attached by means of devices such as springs s (with the exception of the switch R' which is fixed thereto), the contact-fingers of the resistance switches R<2> to R<5>, parallel switches P, P', and a series switch S, all adapted to make contact with fixed terminals D. The shaft A, rotated by means of a solenoid B and divided up by insulating-pieces f, is geared to a second shaft E by means of a sprocket chain 8<b> and a sleeve 8<c> connected to the shaft E by a spring 14. A dash-pot F regulates the movement of the shafts. The contact-fingers R<2> to R<5> are normally kept open by the engagement of extensions 11 with cams 10<1> on the shaft E, which are so arranged that, when a locking-solenoid G is energized by the movement of the master-controller into its second series and parallel positions s<2> and p' respectively, the sections of the resistance r are cut successively out of circuit. The parallel switches P, P' are locked in an open position when the switch S is closed, and vice versÔ, by means of cams 10<2> mountel upon a shaft E<1> rotated by a solenoid H, to the core of which are fastened bridging-pieces 25, 29 controlling the two sets of contacts 26, 27 and 27<a>, 28. The circuit of the solenoid H is broken at the contacts 31, 32 and 31<a>, 32<a>, which are adapted to be closed to prevent the motors from being connected in parallel until the various series connections have been performed, and vice versÔ. On moving the mastercontroller C' from its second series position to its first parallel position p<1>, the circuit of the solenoid B is momentarily opened, whereby the shaft A returns to its initial position with all the resistance r in the motor circuit, and simultaneously the solenoid H is energized, rotating the shaft E<1>, opening the switch S, and closing the parallel switches P, P<1>. In the position p<2> of the mastercontroller, the coil G is again energized and the sections of the resistance r successively cut out of circuit. An overload relay K controls the operation o:E the coils G, H, and an auxiliary switch h serves to open the circuit of one of the actuating- solenoids K, K<1> of the reversing-switch RS when the shaft A is rotated. The shafts A, E, E<1> may be rotated directly and independently by hand &c. The trolley or collector shoe is indicated at T. In the construction of controller shown in Figs. 2, 4, 5, and 6, the core 16, Fig. 2, of the actuating- solenoid B, forced outwardly by a spring 44, is pivoted by a pin 38 to a U-shaped lever 36, an extension 39 of which is connected to the shaft A by a link 41 and a crank-arm 43. The shaft A does not, as previously, form part of the motor circuit, but the contact-fingers are electrically connected. The shafts E, A are coupled by means of a loosely-mounted sleeve 54, Fig. 4, link 47, bell-crank lever 48, and spring 49 fixed to an extension of the crank-arm 43. The sleeve 54 has a projection 54<a>, which serves to drive a projecting lug on a collar 19<a> fixed rigidly on the shaft E. The piston-rod of 'the dash-pot F, working in roller bearings, is connected to the collar 19<a> by a link 52, and the sleeve 54 is joined to the collar 19<a> by a spring 55. When the solenoid B is de-energized and the shaft A returns to its initial position, the extension 43" drives the arm 48<b> of the bell-crank lever, which transmits the movement to the shaft E. The core 18 of the locking- device G is attached to a pivoted link 18<a> carrying a pawl 18<b>, which is moved by a spring 18<c> into the path of a ratchet segment 19 formed on the collar 19<a>. The resistance switches R<1> to R<5>, Fig. 2, each consist of a terminal 60, Fig. 5, mounted upon a flexible bar 61 fastened to an insulating-block 63 and connected by an insulating clamping-block 64 and a link 65 with one arm 66 of a bell-crank lever, the other arm 66<a> of which is engaged by a spring 67 bearing against a shoulder 68 secured to the shaft A. The fixed contact D is arranged within the blow-out chute 70. The switch is opened, when the shaft A rotates in the reverse direction, by the engagement of the shoulder 68 with a lug 73 on the arm 66. The solenoid core 23, Fig. 6, of the series-parallel switch H is pivoted to the bridging-piece 25, which is loosely mounted upon the shaft E<1> and is normally maintained in contact with the terminals 26, 27, Figs. 6 and 1, by a spring 76. When the solenoid is energized, the contact 25 is moved against the terminals 27<a> and 28, and, by means of a spring 22, a second bridging-piece 29, rigidly mounted upon the shaft E<1>, is oscillated into contact with the terminals 26, 27. The solenoid core 34<b> of the overload relay K controlling the contacts 33, Fig. 2, is mounted to move vertically in pivoted links 77. The above control system is also shown adapted for use as a multiple unit system of train control. The switches S, P, P', together with an extra contact-finger, are situated on a separate shaft operated by a solenoid, the circuit of which is controlled by the solenoid B. One half of the resistance r is in series with each of the motors M<1>, M<2>, and two sets of contact-fingers R<1> to R<5> are mounted upon the shaft A, registering with eight cams on the shaft E, which is rotated in a step-by-step manner, so that one section of the resistance in each of the motor circuits is cut out at a time. A ratchet-wheel on the shaft E is driven by a pawl fixed to a lever pivoted to the movable core of a solenoid, which is controlled by the main solenoid B and automatically makes and breaks its own circuit.