Patent GB-152047-A (GB)
Title: Improvements in and relating to telemotors
IPC: B63H25/24
Filed: 1919-04-01
Abstract: 152,047. Alexander, A. E., (Benson Electric Co.). April 1, 1919. Systems controlling travel for a fixed distance or number of revolutions.-In electric telemotors for operating the steering gear of ships, an automatic brake is provided to prevent the continued movement of the parts, due to momentum, beyond the point desired. A generator 1 is connected bv a wire 1<a>, post 1<b>, rail 1<c>, contact point 1<d>, and wire 1<e> with a contact point 1<f>. The point 1<f> is adapted to be moved by a lever, spindle 2<a> and arm 2<b> into contact with one of a number of stationary contact points 3, 4, 5. The same enerator pole is also connected by a wire 1g with one pole of the shunt field 6 of a motor 7, and through a normally open contact 8 and wire 9 with one pole 7a of the motor armature and thence through wire 11, normally open contact 15, and wire 13 with one of the poles of a series field 14 of the motor. The same generator pole is also connected through wire 1g, a normally open contact 10, and wire 11, with the opposite pole 7<b> of the armature and thence through wire 9, a normally open contact 12 and wire 13 with the series field. The opposite pole of the series field is connected through wires 16, 17 with the opposite generator pole, and the opposite pole of the shunt field is connected through wires 18, 17 with the lastmentioned generator pole. The positive generator pole is also connected through normally closed contacts 19, 20 with one pole of an electromagnet 21 and through it to the negative generator pole. The poles 7<a>, 7<b> of the motor are connected through a resistance 22, and a normally open contact 23 which is adapted to be closed by the movement of the armature 21a of the magnet 21. The contact points 3, 4, 5 are connected by wires 3<a>, 4<a>, 5<a> with corresponding insulated stationary points 3b, 4b, 5<b>. The latter are in contact with a sliding bar composed of two conducting parts 25, 25a divided by an insulating part 27 which may insulate any one of the contacts 3<b>, 4<b>, 5<b>. The section 25 is connected by a stationary contact 28 and wire 29 to a magnet 30 and through it to the negative generator pole. The magnet 30 is adapted to close simultaneously the contacts 8 and 15 and open the contact 19. The section 25<a> is connected by a stationary contact 31 and wire 31a with one pole of a magnet 32 and through it to the negative generator pole. The magnet 32 is adapted to close simultaneously the contacts 10 and 12 and open the contact 20. The carriage 26 of the contact bars 25, 25<a> is operated by the motor 7 through gearing 33, 34, 35, 36, 39, 40, 41, 42. The link 43 is adapted to be connected to the valve of a steam steering or other engine. Under the conditions shown in Fig. 1, the apparatus is at rest, but if the arm 2b is moved so that the contact 1<f> covers the point 5, the circuit 1, 1<c>, 1<d>, 1<f>, 5, 5a, 5b, 25a, 31, 32, 1 is completed. The magnet 32 closes the contacts 10 and 12 and opens the contact 20 so that current flows through the circuit 1, 1g, 10, 11, 7<b>, motor 7, 9, 12, 13. series field 14, 16, 17, 1. The motor is thereby operated and moves the carriage 26 so that the contact 5<b> is insulated by the insulation block 27. The magnet 32 is then de-energized and the contacts 10, 12 opened so that the motor is stopped, while at the same time the contact 20 is closed. This latter completes the circuits 1, 1g, 19, 20, 21, 1, and 1, 1g, 6, 18, 17, 1. The magnet 21 then closes the contact 23 and short-circuits its armature through 9, 11, 22, 23 so that the motor which now operates as a generator through its own momentum is quickly stopped. The process is repeated if further contact points similar to 5 are used, while if the contact 3 is covered by the arm 2<b> the action is similar except that the motor is reversed.