Patent GB-266508-A (GB)
Title: Improvements in or relating to synchronizing clock systems
IPC: G04C11/00
Filed: 1926-01-19
Abstract: 266,508. White, A. E., (International Time Recording Co. of New York). Jan. 19, 1926. Synchronizing.- An alternating-current synchronizing clock system includes a master clock, a main synchronizing , clock, and secondary clocks, the voltage of the main circuit being varied in order to advance or retard the various clocks. The main synchronizing clock 8, Fig. 1, and secondary clocks 9 are constructed similarly to watt-hour meters and have a potential coil 18, a regulating coil 19, a second regulating. coil 27, and a resistance 26 the clock hands being geared to the spindle of the rotating disc 23. The magnet 32 may be adjusted radially across the disc. An auto-transformer 5 has terminals 3, 4 connected by lines 1, 2 to the supply source and an adjustable intermediate connection 6. The main clock circuit 7 includes a line 11 from terminal 3 to the secondary clocks and a line 12 connecting the clock 8 with the clocks 9 and also with the middle of a switch arm 13, 14. A contact 78 of this switch is normally in contact with a line 16 to terminal 4, but its other contact 77 may connect with a line 15 to terminal 6. At each secondary clock the coil 18 is connected by lines 35, 34 to the lines 11, 12 respectively, and at the master clock 36 a shaft 37 coacts with the shaft 62 of the clock 8 in the following manner. A member 39 rigid with the shaft 37 carries two contacts 45, 46 connected through collector rings 43, 44, with stationary brushes (not shown). The contact 45 is rigid on the member 39 but the contact 46 is at one end of an arm 47 pivoted at 48 and movable by means of a pin 53 extending through a slot 55 in the member 39. This pin 53 is rigid with an arm 56 pivoted at 57, a spring 58 tending to cause the end 59 of an arm 56 to abut a lug 61. In this position the contacts 45, 46 are disengaged, but when the parts 59, 61 are separated the contacts 45, 46 close. The shaft 62 of the main synchronizing clock 8 is geared by wheels 63 with a wheel 64 loose upon the shaft 37 and rigid with arms 65, 66, the latter having a bobweight and the former a latch which normally engages the end 59 of arm 56, causing contacts 45, 46 to close; when the clock 8 loses, 59 passes ahead of 68, 59 and 61 abut each other, and contacts 45, 46 open. The normal engagement of the end 59 and latch 68 is effected by so designing the coil 19 of clock 8 that the latter rotates slightly faster than the master clock. The contact 45, Fig. 1, is connected by line 69, 70 to terminal 3 and contact 46 by line 71 to line 15 through a winding 72 which, when energized, closes contacts 77, 79 and opens contacts 78, 81. Thus, when the clocks 8 and 36 are synchronous the circuit is 3-7-69-45-46-71-72-15-6 and contacts 77, 79 are closed to connect line 12 of the secondary clocks to line 15 and terminal 6, so that normally currents of relatively low voltage are supplied to the main circuit 7. When the clock 8 loses, latch 68 lags behind, contacts 45, 46 open, and winding 72 is de-energized, closing contacts 78, 81 so that line 12 is connected by line 16 to terminal 4 and the secondary clocks receive a current of increased voltage which steps them on. If the secondary clocks 9 differ from the main synchronizing clock 8 a conductor 73 is used which is connected by contacts 74, 75 of a relay 76 to the switch 13, 14, this relay being controlled by switches 82, 83. At the switch 83 the contacts 84, 85, 86 are controlled by cams 92, 93, 94, Fig. 4, so that for ten minutes in each half hour contacts 85, 86 are closed. The switch 82 is closed once per minute by the clock 8. Contacts 85, 86 close a circuit 3 - 70-101-102-98-103-104-82-105-85- 86-106-15-6. This energizes the winding 98 of relay 76, which thereupon closes its contacts 74, 75 and 107, 108. Closure of contacts 74, 75 connects line 73 with terminal 6 or 4 according to the position of the switch 13, 14, so that the secondary clocks receive current of the appropriate voltage according to the state of synchronism. Closure of contacts 107. 108 shunts switches 82, 83, through line 109. At the end of the ten minutes contacts 84, 85 are closed so that the relay winding 98 is shunted by the circuit 99-110-84-85-105-82-104-103. Deenergization of winding 98 opens the contacts 107, 108 and 74, 75, and subsequently contacts 84, 85 open and 85 remains in a neutral position. Each secondary clock is advanced or retarded according to the direction of the current through the controlling coil 27, and this direction is decided by the position of a double switch 111 which is cam-actuated from the minute shaft of each secondary clock.