Patent GB-565670-A (GB)
Title: Improvements in or relating to electrical apparatus for counting passing objects
IPC: G06M7/04
Filed: 1941-03-05
Abstract: 565,670. Counting devices. AUTOMATIC SIGNAL CORPORATION. March 5, 1941, No. 2997. Convention date, March 30, 1940. [Class 106 (i)] Electrical apparatus for counting passing objects by a switch assembly is characterised by a series of switch elements arranged to be operated in sequence by the objects to be counted, a plurality of pairs of cooperating contacts adapted to function in response to the operation of the switch elements whereby the apparatus will function in response to a successive operation of the series of elements, irrespective of the substantially permanent opening or closing of the circuits incident to a continuing operation of one of the switch elements and corresponding or continuing co-operation or lack of co-operation of the pairs of contacts associated therewith. Forward operation.-Assuming a car wheel to be passing over the treadle depressing switches 1, 2, 3, 4 in that order, when switch 1 is depressed, a relay A is energized and closes contacts a<1>-a<4> and opens a<5>. Switch 2 similarly causes the closing of contacts b<1>-b<4> and opening of b<5>. One of a group of circuits for energizing a relay P, whenever two of switches 1, 2, 3, 4 are closed, is thus completed via contacts a<1>, b<1>, and relay P closes contacts p<1>, p<2> and opens p<3>. Contact p<1> completes a circuit through relay T which is of a predetermined time delay type such as described in U.S.A. Specification 1,909,471. Normally, relay P de-energizes to break the circuit before relay T energizes, but if for some reason, such as a jammed switch or a car resting on the treadle, relay P remains energized for a considerable time, relay T also energizes to operate alarm lamp L, bell BL and a device 67 which prints the number of occasions on which the switches are closed for an excessive time. Closure of contacts a<4>, b<4> energizes relay F, via contact r<2>,' and relay F locks up via contacts f<3> and p<2>, so as to remain energized as long as relay P. Depression of switch 3 establishes another circuit to relay P which remains energized when switch 1 is released. When the wheel depresses switch 4 and releases switch 1 or switch 2 if switch 1 jams, relay F prepares a circuit to energize relay FS via contacts c<5>, d<5>, f and a<5> or b<5>, and relay FS closes its contacts fs<1>, fs<2> and locks up via contacts fc<2>, fs<1> and a<5> or b<5>. As the wheel rolls on to release all but the last switch, relay P is de-energized and contact p<3> closes to energize coil FC through contact fs<2>. Coil FC pulls down armature fc<1> to advance the counter ratchet 71 one count and to open contact fc<2> to break the holding circuit of relay FS, so that contact fs2 opens to de-energize coil FC and restore armature fc<1>. The de-energization of relay P also opens contact p<2> to de-energize relay F. When switch 4 is released, the apparatus is restored to original condition. Interruption of the proper operation of relays F and FS by permanent depression of any of switches 1-4 is prevented by the use of series circuits through the make contacts of relays A, B and C, D and parallel circuits through contacts a<5>, b<5> and c', d<4>. As described below, the proper operation of relays R and RS is also assured. If one of switches 1, 2, 3 is permanently depressed, counter 71 is actuated late at the release of switch. 4. ' Reverse operation.-In a similar manner to that described above, when relays D and C are energized, relays P and R are energized, the latter locking up and preparing a circuit to relay RS as soon as switches 2 and 1 are operated and switch 4 or 3 released. When only switch 1 remains depressed, relay RC is energized to actuate counter 70. If a car should roll partly on to the treadle and then roll back, actuation of the counters is prevented by an electrical interlock between relays F and R, energized respectively through. contacts r<2>, f<2>, so that initial operation of the one prevents operation of the other until the first has been released on completion of the count, which takes place only when the wheel has passed completely over the treadle.