Patent GB-191207168-A (GB)
Title: Improvements in and relating to Devices for Controlling Mechanisms.
Inventor: BLOXAM ARTHUR GEORGE
Filed: 1912-03-23
Granted: 1913-04-23
Abstract: 7168. Bloxam, A. G., [Russische Akt.-Ges. L. M. Ericsson & Co.]. March 23. Systems for controlling travel for a fixed distance or number of revolutions.- In a motor control system of the kind described in Specification 2819/11, the disk and contact devices of the receiver are modified to give two speeds to the motor, by short-circuiting a resistance in its armature circuit after the controlling- arm has moved through a certain angle, and to insert this resistance when the motor is nearing the end of its travel. The apparatus at the receiving station comprises a synchronous motor A<1> Figs. 3 and 4, connected to a hand 71 and an arm 70 through worm gearing 67, 68; a disk 76 and a hand 80 connected to the mechanism to be controlled through gearing 87, 88; and a dial 81. The arm 70 carries two levers 73, 73<1> normally held in a radial position by means of a spring 75. The levers 73, 73<1> are provided with rollers 74, 74<1>, which normally lie in a slot 77 in the disk 76 having a second slot 78. The arm 70 also carries a series of insulated contacts 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, Fig. 5, adapted to be brought into engagement by means of projections 91, 92 on the lever 73 when the lever is moved from its normal position. When the arm 70 is moved from its normal position in a clockwise direction by the motor A<1>, the lever 73 engages the edge of the slot 77 and causes the projection 91 to force the contact 98 into engagement with the contact 100, and the contact 94 into engagement with the contact 96, thereby completing the circuit of the operating- motor j as follows:-Leads 107, 109, 111. contact 99, lead 112, contacts 94, 96, lead 113, contacts 114, 115, lead 116, contacts 117, 119 of the switch P, lead 120, motor j, resistance 229, lead 124, contacts 125, 126, lead 127, contacts 128, 129, lead 130, contacts 100; 98, and leads 131, 133, 135. Upon a further movement of the arm 70, the lever 73 engages the edge of the slot 78 and causes the projection 91 to force the contact 100 into engagement with the contact 102, thereby shortcircuiting the resistance 229 by means of the lead 136, contacts 137, 138, lead 139, contacts 140, 141, leads 142, 144, contacts 102, 100, 98, and leads 133, 135. The adjustable and stationary near control devices are provided with similar arrangements by which two speeds of the motor may be obtained, the adjustable device having a handle with a lever adapted to move, when pressed, an insulating block carrying contacts. In the arrangement shown in Fig. 6, a relay R is employed to control the circuits of the motor j. When the arm 70 moves in a clockwise direction, thereby causing the lever 73 to engage the edge of the slot 77, the projection 91 will engage a contact 211 to establish the following circuit: -positive terminal of battery 205, leads and contacts 206, 210, 75, 73, 91, 211, 212, 129, 128, 213, 126, 118, 125, 214, relay winding 215, lead 217, and the negative terminal of the battery 205. The armatures 218, 219 of the relay R are attracted to close the circuit of the motor j as foUows:- Leads 107, 226, 219, 221, motor j,. resistance 229, and leads 230, 220, 218, 135. A further movement of the arm 70 causes the lever 73 to engage the edge of the slot 78 to shortcircuit the resistance 229 by means of leads 228, 235, contacts 232, 231, lead 236, contacts 114, 115, lead 237, contacts 117, 118, 119, and lead 238. In each of the arrangements shown in Figs. 5 and 6, a similar control of the motor j, rotating in the reverse direction, is obtained by causing the arm 70 to move in an anticlockwise direction. As the operation of the mechanism to be controlled causes the disk 76 to follow the arm 70, the resistance 229 is first inserted in the circuit of the motor j, and finally the circuit of the motor is broken.