Patent GB-437621-A (GB)
Title: Improvements in or relating to electrical signalling and time recording systems and apparatus
IPC: G07C1/20
Filed: 1934-06-28
Abstract: 437,621. Time-recorders; electric selective signalling systems. ERICSSON TELEPHONES, Ltd., 67, Kingsway, London, and WILMAN, C. W., Ericsson Telephone Works, Beeston, Nottingham. June 28, 1934, No. 19097. [Class 106 (iv)] [See also Group XXXVIII] A recording system comprises contact-making devices operable by any one of a plurality of keys inserted by employees to close a combination of electric circuits characteristic either of the key employed or of the key and the device into which it is inserted, and a recording device actuated both by signals received over said circuits and also by time signals. When a key 16 is inserted in the device or key-box 17, a projection U closes one of ten units contacts u and a projection T closes a tens contact t. The key also has either a projection HA as shown to actuate contacts ha, or it may have a projection which actuates contacts hb. Two hundred different keys can thus be used with the box 17. Another set of keys may be similar, but may have a different cross-section so that they can be, fitted only into another box 17, a slot in a plate 15 being shaped to correspond to the section of the key. The contacts are connected as described below to magnets operating hammers which print the number of the key on a record strip in the manner described in Specification 384,697. Other magnets cause a mark to be printed on the strip every minute. When the number has been recorded, a lamp L is lit to advise the employee that he may withdraw the key. The record strip is advanced each time any magnet is operated. Connections. When a key is inserted, contacts ha1 and ha2, Fig. 7, or hb1 and hb2 are closed. In each case, earth potential is transferred to line 1 to operate relay ST. If the wiper w1 of a step-by-step switch is not on the line 2 connected to the key-box in which the key is inserted, a circuit is completed from earth through contacts hb2, ha2 of some other key-box, wiper w1 at that time connected to those contacts, line 4, st1, s2, za4, interrupter dm, and relay G to battery. Relay G closes contacts g1 to energize the switch-operating magnet DM whereby the wipers w1 ... w5 are advanced one step. This continues until the wiper w1 reaches the line 2 connected to the key-box in use. Contacts ha2 or hb2 are here open so that a relay H is no longer shortcircuited but is operated and held via h5. The resistance of H prevents operation of G so that the wipers w1 ... w5 are held stationary. The units, tens and hundreds printing magnets UP, TP and HP are now energized from wipers w5, w4 and w3 through the key-closed contacts ha1, t and u. The number of the inserted key is thus printed and relays CU, CH, CT are operated. The contacts cu1, ct1, ch1 complete a circuit for a relay Z which opens contacts z3 to release the printing magnets. Advancing the record strip. Contacts z2 complete a circuit for a shifting magnet SM, the contacts sm of which close a circuit for a relay ZA which opens za3, whereupon SM releases and advances the record strip. Indicating completion of operation. Contacts z5 close to complete a circuit for a lamp L situated at the key-box to indicate that the key can be withdrawn. Recording time. An impulse is sent by means not shown once every minute to a relay C, the contacts c1 of which complete a circuit for a relay S. Contacts s4 make a circuit for the top magnet of a set of three printing magnets SP, a mark being printed on the strip. The circuit through SP is continued via a relay CS which closes contacts cs1 to operate a relay ZT. Contacts zt3 and relay ZA then cause the shifting magnet SM to advance the record strip. At the end of the time impulse, relay S releases and opens contacts s5 which cause a magnet TDM to advance the wipers wt1, wt2, wt3 of a step-by-step switch. This switch is thus advanced once every minute. At every fifth minute a second magnet SP is actuated, and at every fifteenth minute a third magnet is also actuated to make extra marks on the record at these times. In a modification, instead of the time being printed on the strip, the latter is periodically stepped forward by electromagnetic means actuated by timecontrolled impulses.