Patent GB-732216-A (GB)
Title: Improvements in apparatus for checking the performance of patrols or tours of inspection by watchmen and the like
IPC: G07C1/20
Filed: 1952-11-24
Abstract: 732,216. Checking watchmen. NORFOLK ;  C. L. Feb. 24, 1954 [Nov. 24, 1952], No. 29701/52. Addition to 688,274. Class 106 (4). The apparatus of the parent Specification for checking the performance of patrols is modified by associating with each route switch for control thereby a route relay adapted upon operation to contribute to the attainment of one of the electrical conditions in the line or network. In the embodiment shown in Fig. 1, the control unit comprises a source of D.C., a timing g device 13, which may be a synchronous electric clock movement; indicating means, e.g. lamps 14, 15; a counter 16 and various relays. A pair of lines 18, 19 lead from the control unit to each of a series of " route " switches 20, situated at selected localities on the patrol route, each having its common contact connected to a " route " relay 21 in the control unit, each relay controlling one of a series of switches 21c in a control line 17. A cycle of operations is initiated by closing a mains switch 23 whereupon the timing device 13 alternately opens and closes a pair of contacts 22 at the time a patrol should begin. Assuming the contacts 22 have just been closed, timing relay 24 closes 24 (c) to energize indicating relay 26 which (a) closes 26 (b) to light lamp 15 through 28 (d), thus indicating a patrol is due to begin, and (b) closes 26(d) to apply a potential to line 19. When a watchman has operated all the switches 20 on his route to energize through line 19 all the relays 21 and close all the contacts 21 (c) in the line 17, the patrol is registered by the energization of the counter 16 through 28 (e) before slow-acting control relay 28 is energized to (a) open 28 (e) and ensure that any " flashing " of the switches 20 will not actuate the counter 16; (b) open 28 (d) to extinguish lamp 15, thus indicating the patrol has been completed, and (c) close 28 (c), which through 26 (b) holds relay 28. When the next patrol is due, the device 13 opens contacts 22 to de-energize relay 24 which opens 24 (c) and closes 24 (d), thus de-energizing relay 26 which (a) opens 26 (d) to clear line 19; (b) opens 26 (b) to de-energize relay 28, and (c) closes 26 (c) to energize indicating relay 25 to light lamp 14 through 25 (b) and 28 (b), thus indicating the next patrol in due and closes 25 (d) to apply a potential to line 18. In his second patrol the watchman operates all the switches 20 to energize through line 18 all the relays 21 and whereby establish continuity the control circuit 17 to extinguish the lamp 14, indicating completion of the patrol, and to actuate the counter 16. The relays 21 may perform additional functions thus lamps 29 on an indicator board in a supervisor's office may be placed in series with contacts 21 (a), being lit at the beginning of a patrol and extinguished one by one as the switches 20 are operated and should the watchman wish to call assistance repeated operation of a switch 20 would cause flashing of the corresponding lamp 29. The indicator board could be in the form of a plan of the premises with lamps 29 in positions corresponding to the switches 20 or it could be an array of lamps 29 behind windows bearing corresponding symbols. A plurality of such boards could be wired in parallel, one for the watchman himself to verify that he has properly operated all his switches 20. The relays 21 could also operate an alarm, e.g. the closing of contacts 21 (c) could establish an alarm circuit which would be completed upon premature release of the relay 21 by operating the associated switch 20 more than once in a patrol period. Closing contacts 21 (c) energizes, " alarm " relay 30 which establishes its own holding circuit through contacts 30 (a) and alarm means, connected across terminals 32 in an alarm circuit 31 including contacts 30 (b) and 21 (d), will be energized if the switch 20 is operated again in the patrol period to close contacts 21 (d). The alarm means may be held energized until switched off by an independent switch. The operating circuits of the alarm relays 30 include contacts 24 (e) and 24 (f) controlled by the timing relay 24 so that the relays 30 are de-energized when a new patrol is due to begin thus avoiding the consequent release of. the relays 21 from completing the alarm circuit. A warning circuit may be incorporated to give an alarm if, when one patrol is due to begin, the previous patrol has not been completed. A suitable circuit comprises contacts 25 (e), 26 (e) controlled by the relays 25, 26, a contact 28 (f) controlled by relay 28 and " warning " relays 33, one being energized at the beginning of a patrol and establishing its own holding circuit through contacts 33 (a). Contacts 33 (b) in series with 25 (f) and 26 (f) are incorporated in an alarm operating circuit 34 shunted across terminals 32 so that the relay 28 opens contacts 28 (f) an alarm will be given. When the switch 23 is opened at the end of a tour of duty the switches 20 remain in the positions occupied at the end of the last patrol, e.g. as shown. If, when the switch 23 is next closed the contacts 22 are open, the relays 21 will operate to complete the circuit 17 and the counter 16 will register without a patrol being made. To guard against this, a resetting relay 27 is provided and energized through the circuit 17 and contacts 25 (a), 26 (a) to interchange, through its contacts 27 (b) and 27 (d), the operations of the relays 25, 26 with respect to the operated and released conditions of the timing relay 24 before the counter 16 and relay 28 can operate, the relay 27 being faster than any of the relays 25, 26, 28 or the counter 16. When the resetting relay 27 operates it establishes its holding circuit through 27 (a) and 24 (b). When the next patrol is due to begin the relay 24 operates and opens contacts 24 (b) to release relay 27, which immediately re-operates to cross the lines again. The energization of the route relays 21 prior to each energization of the resetting relay 27 operates the alarm relays 30 which prepare the alarm circuit 31. To avoid this circuit being completed when energization of the relay 27 releases the relays 21, contacts 27 (f), 27 (g) are included in the holding circuits of relays 30. In the embodiments of Figs. 2 and 3, not shown, the indicating control and resetting relays are replaced by a uniselector switch, having the two alternative lines to the route switches connected to alternate contacts of one bank and the two indicator lamps to corresponding contacts of a second bank, the lines being selected alternately with the stepping of the wipers. The pair of timecontrolled contacts are replaced in the second embodiment by two pairs, one momentarily opening each time a patrol is due to begin and the other momentarily closing immediately before to instigate a warning if the previous patrol was not completed, and in the third embodiment by a pair of contacts momentarily closed when a patrol is due and performing both functions with modified circuitry. Various warnings and alarms are provided and precautions taken to ensure that the uniselector is only advanced once at the end of each patrol, multi-stepping by flashing the route switches being prevented. In these embodiments the number of patrols may be counted by adapting the uniselectors to move calibrated discs in unison with their wipers or by including a counter in their operating circuits. Moreover, the two lines to the route switches could be replaced by a plurality of lines appropriately connected to groups of contacts at the uniselector and connected tp appropriate singlepole multi-way type " route " switches to be set to a different position for each patrol indicated by the lighting of a corresponding lamp. In all embodiments the control unit may be housed in a locked cabinet, the power supply may be suitably protected and should any one tamper with the external wires or switches the alarm provided will operate either immediately or when a patrol is due to end. Various minor modifications are suggested.