Patent GB-238622-A (GB)
Title: Improvements in and relating to synchronising systems
IPC: H04L7/00
Filed: 1924-05-23
Abstract: 238,622. Higgitt, H. V., and Eastern Telegraph Co., Ltd. May 23, 1924. Driving-arrangements.-In an electric synchronizing system, particularly applicable to telegraphic apparatus, the stator of an electromotor driving one of the sets of apparatus to be synchronized is rotated in one or either direction, preferably in small momentary steps, in response to current impulses received from the other set of apparatus, the absolute speed of the motor shaft being thereby increased or decreased. In the construction shown, the carcass 1 of an electromotor is rotatably mounted in bearings 2, connections to the motor being made through sliprings. The rotor shaft 3 carries two pulleys 4, 5 which are geared respectively by belts 7, 8 to pulleys 33, 34 attached to bevel wheels 31, 32 loose on a spindle 11. The wheels 31, 32 together with an intermediate bevel wheel 15 mounted on an arm 30 projecting from the spinde 11, constitute a differential gear by means of which a pinion 16 on the spindle, gearing with a wheel 17 on the motor casing, may be caused to rotate the casing in either direction. Normally, the pulleys 33, 34 are held by the engagement with pins 35, 36 thereon of latches 13, 14, which form the armatures of electromagnets 28, 29, so that the belts 7, 8 slip on the pulleys. The magnets are connected to contacts 40, 41, between which is arranged a contact blade 21 operated by an eccentric 6 on the motor-shaft 3. The magnets 28, 29 and the contacts 21, 40, 41 are arranged in circuit with a battery 19, a condenser 20, and a relay 18 comprising a tongue 38 which is moved from a contact 39 into engagement with a contact 42 each time a signal current passes through the winding of the relay. Closure of the contacts 42, 38 sends an impulse through one or other of the magnets 28, 29 according as the blade 21 is on either 40 or 41 at that instant. With the arrangement described, energization of either magnet 28, 29 causes its armature to release the corresponding pulley 33 or 34, and thereby allows the wheel 15 to move upon the bevel wheel that remains locked. Thus, the casing of the motor 1 is turned so as either to speed up or retard the shaft 3. This shaft is required to make one revolution per signal element received by the relay 18. If the speed of the shaft is too fast or too slow, there will be a preponderance of current impulses through one or other of the coils 28, 29, which will result in the necessary correction being applied. In a modification, the belts 7, 8 are dispensed with, and the members 33, 34 consist of toothed wheels, each meshing with a chain having a driving weight, which weights tend to turn the wheels in opposite directions. Where the motor is adjusted to run at a speed above that required for normal working, the reaction of the armature torque upon the stator may be utilized for intermittently rotating the stator, so as to reduce the mean speed of the rotor as required. In this arrangement, the belts 7, 8 and bevel-gears are dispensed with; the latch 13 acts upon pins 35 on the member 33, as in the construction described above, and thus momentary rotations of the shaft 11, allowing the carcass of the motor to turn, occur only when impulses pass through the magnet 28, Specification 234,179, [Class 38 (v), Electric switches &c.], is referred to.