Patent GB-609279-A (GB)
Title: Improvements in or relating to devices for giving indications relating to the occupation of seats in places of entertainment and the like
IPC: G08B5/22
Filed: 1946-03-11
Abstract: 609,279. Seat indicators. FLETCHER, R. A., and BEVAN, L. H. March 11, 1946, No. 7508. [Class 106 (iii)] To indicate the number of seats occupied in an auditorium and the time each seat has been occupied, the shaft 2 of a shaded disc indicator 16 individual to each seat, is coupled to a common constantly running shaft 1 by the energization of a magnet 7 by a seat-operated switch 6. To bring about the coupling the magnet moves the shaft 2 axially to bring worm and worm-wheel 4, 5 into mesh. At the same time the indicator is rotated a few degrees by engagement of a pin 14 on its shaft with an incline 15 to give an immediate indication that the seat is occupied. On the release of magnet 7 by seat-switch 6 a torsion spring 8 and axial spring 13 restore the indicating element to its original position. To prevent this happening when the seat is vacated for a short while only, the switches 6 may be of the time-delay type, described in Specification 569,754. Alternatively, the shaft 2 may be latched in the engaged position by a wire 12 which is moved clear by a constantly driven cam 10 after a suitable interval. Various modifications described in the Provisional Specification include thermally-operated clutches to mesh the two shafts together, thermal switches to control the current flow to the electromagnet, thus providing a delay action, and a system in which the worm-gearing is always in mesh, but is coupled to the shaft by an electromagnetic clutch. Other indications also described include a lamp 30 on each seat fed through contacts 36 which shines when the seat is unoccupied, contacts 36 being broken when the shaft 2 carries cams 39 and 38 longitudinally. If the seat is occupied for longer than a performance, contacts 37 are closed by a surface of the cam 39 and lamp 30 is flashed. If any one seat in the row is occupied a coil 41 in series with the seat switches 6 actuates a relay 42 causing a light 31 at the end of the row to shine. The state of advancement of the performance may be indicated to the box office by providing cams 51 on the main shaft 1 which close contacts at prearranged points in the performance causing lamps 33 to shine. Counting arrangements.-To count the number of unoccupied seats, switch 45 is closed manually and arm 46 is moved over contacts 47 fed through the cam actuated contacts 34, an impulse being given to the counter 32 for every pair of contacts 34 which are still closed. Counting of the seats which have been occupied longer than a performance is carried out by closing switch 48 and operating arm 46 as above, the impulses now being received through contacts 35 which are closed only when the shaft 2 has rotated through a prearranged angle. Further counting arrangements described in the Provisional Specification include an arrangement in which the subsidiary spindles close quarter, half or three-quarter period contacts which are contacted to contacts on a ring which are periodically " scanned " by an arm, or these contacts may be used to adjust a variable resistance thus controlling the electrical flow in a circuit and indicating the number of seats occupied on a suitable meter.