Patent GB-191514145-A (GB)
Title: Improvements in and relating to Electric Indicating and Lighting Systems.
Inventor: BLACKMORE ALFRED
IPC: G08B5/36
Filed: 1915-10-06
Abstract: 14,145. Blackmore, A. Oct. 6. Station, stopping-place, and like indicators.- In a device in which, when a switch corresponding to a desired destination is operated, the destination and the route to it are illuminated on a plan or map, the lamp circuits are controlled by relay devices. When applied to a building, the lamps, instead of illuminating a plan of the building, may be distributed in the various corridors and rooms, so that, on closing the switch, the actual route to the destination is illuminated. Fig. 1 shows a panel 5 depicting in plan various departments of a store and the routes thereto, adapted to be illuminated from behind. The portion L, corresponding to the position of the indicator, may be permanently illuminated. Destination switches are arranged in a column 2 adjacent to panels 3 giving the names of the departments. A compartment 4 contains the relays 11. " Department " lamps 6, Fig. 3, and " route " lamps 7 are connected directly to a positive lead 8. Two-pole switches 10, normally open, and corresponding to the various departments, are provided, directly connected to a negative lead 9. One contact of each switch is connected to the corresponding department lamp, the other contact being connected through a solenoid 11 to a route lamp 7. Each solenoid 11, when energized, is adapted to close a contact 12 in a circuit connecting the adjacent solenoid and route lamp to the negative lead. Thus, when any destination switch 10 is closed, the corresponding department and route lamps are at once illuminated, and the route lamps leading back to the starting place L are successively illuminated. The arrangement can be extended to branch routes, two such branches being illustrated. A modified arrangement is described in which the route lamps are successively illuminated from the starting point to the destination. In this case. the destination switches normally form part of the positive lead, the department lamps being normally disconnected from the lead. When a switch is operated to connect the required department lamp, the lead is broken for all points beyond that switch. When branch leads are necessary, each contains a solenoid-operated contact arranged so that, when a destination switch in one of the branches is closed, all the other branches are disconnected. A further modification is described in which route-lamp solenoids control additional contacts whereby the switches, up to that which has been operated, are successively bridged, so that arcing is avoided should one of these switches be accidentally opened. Any suitable device may be used to prevent operation of a second destination switch during any desired time interval after operation of the first, which is automatically returned at the expiry of the interval. As shown in Fig. 6, the switch arms 25 extend through slots in a vertically-moving plate 26, which is depressed-by the operation of any switch and is held by a catch 35. A laterally-moving plate 29 having pin and camslot connexions 34 with the plate 26 is moved thereby to bring projections 32 into the paths of the corresponding arms 25, thereby preventing their operation. The catch 35 is released by any suitable time-device, whereupon the plate 26 is automatically raised, returning the plate 29 and opening the closed switch. The solenoids described operate a contact coacting with two inclined spring contacts which aid gravity in breaking circuit when the solenoid is de-energized. The device may be modified for use with a distant-control switching-apparatus such as is described in Specification 8305/05, [Class 38, Electricity, Regulating &c.].