Patent GB-833362-A (GB)
Title: Industrial computing scale
IPC: H03M1/00
Filed: 1956-07-13
Abstract: 833,362. Electronic calculating-apparatus. TOLEDO SCALE CORPORATION. July 13, 1956 (Aug. 11, 1955; June 21, 1956], No. 21807/56. Class 106 (1). [Also in Group XL (b)] A weighing, measuring or indicating apparatus exposes by means of a sliding mask the graduations of a stationary chart and a station. ary photo-cell scans the chart and electronic means count the pulses generated by the photocell, multiplying as necessary by a fixed factor. The counts may be stored and means responsive to the completion of a scan clears the storing means and causes transfer of the accumulated count to indicating means. The counting circuit is shown in Fig. I, pulses corresponding to the weight reading being generated by the scanner 1 in short intervals or in response to a starting signal. They are fed by a line 2 through a wave shaping and identifying mech. anism 3 to a multiplier pulse generator 5 for multiplication by the selected factor. The pulse generator 5 may be omitted. The resultant pulses feed to the decade counters 7-10, the sum up to several thousands of units being indicated and/or printed by device 12. The generator 5 feeds lines 13, 14, 15, 16 to give for each pulse on line 4 an output of two, four, two and one pulses respectively which are fed to a diode matrix network 18 so as to energize nine leads in a cable 19 connected to selector switches in the multiplier device 20 set to the appropriate factor. This factor may be price, pieces per unit weight, humidity, &c. The common arms of the selector switches are connected through combining amplifiers 25, 26, 27 to decades 29-34 and so to an amount indicator 36. Carry pulses from one decade to another in the set 29, 30, 31 are stored in storage circuits 38, 43 until cleared or triggered by pulses from generator 5 fed through terminals 39, 44. A start signal on lead 47 fed to sequence control 48 sends a reset signal over leads 52 to all the decade counters which are all restored to zero with the exception of counter 30 which is preset for rounding off to the nearest cent or unit. An end of scan signal from reading device 1 to sequence control 48 energizes the visual indicating devices 12, 36 and the printing wheels (if used). The weighing mechanism, Fig. II.-Load, forces applied to a steelyard 67 are transmitted. equally through load tapes 68, 69 to eccentric arcuate sectors of two pendulums 60, 61. which are supported by flexible steel ribbons 63, 64 from a sector guide 62; The pendulum rolls upwardly raising a compensating bar 72, its movement being translated to a rack and pinion 73, 74 which carries an indicator 75, and to an upwardly extending rod 78 carrying a mask 79, its movement exposing the graduated chart 80 of the reading device 1. The steelyard may alternatively be connected to the mask through. first and second class levers provided with a. counterbalancing spring (Fig. III, not shown). The reading device, Fig. IV.-The exposed. chart 80 is scanned by light from a stationary bulb 101 which is transmitted by elements on a rotating turret 103 comprising lenses 104, mirror 106, projection lens 109, and reflected by a stationary mirror 111 on to a masked photo-cell 112 which accepts only the projected image of one scale graduation. The turret is driven by a motor 83 through belt 81 and has a coil spring clutch 124 brought into and out of operation for one completed rotation by a solenoid-operated latch (Fig. VI, not shown). Electronic counter and control circuits.-The pulses from the photo-cell are amplified and shaped by means of a Schmidt trigger circuit (Fig. VII, not shown), and fed to the lead 4. The same pulses are further amplified to give a large low impedance pulse signal to be used as desired to reset the counters. The multiplier pulse generator 5 where the scale readings are multiplied by an arbitrary factor, comprises a series of blocking oscillators which operate so that for each input pulse, outputs of two, four, two and single pulses respectively are obtained across different resistors at points 13, 14, 15, 16, their leads being connected to nine leads of the diode matrix 18, giving an appropriate number of pulses as selected by the factor setting. The factor is set by three selector switches 21, 22, 23 connected to the nine lines. The decade counters each comprise four flipflop circuits (Fig. X, not shown), with feedback connections to give an artificial injection of six additional impulses to complete the cycle in ten pulses instead of sixteen. Electromechanical readout (Fig. XII).-The eight readout terminals of a decade counter are contacted in pairs by switch levers 316-319, symbolic representations of a commutator or stepping switch determining the count. The common line is taken to the grid 320 of an amplifier operating a relay 323 which controls a frictionally driven-star-wheel 325. A smooth portion of the star-wheel is engageable with a rubber-tyred drive wheel 328. A commutator R (Fig. XIII, not shown) on the indicator drum is driven by the wheel 328 upon withdrawal of. latch 324. When all the selected combinations with the different decade counters have been made by the commutator, the tube 321 conducts and operates the latch 324 to contact the tooth of the star-wheel and disengage the drive, stopping the indicator and printing wheels 327, 329. The circuits, timing relay operations and pulse synchronism ensuring safe, rapid and accurate operation of the apparatus are described in the Specification (Figs. XI, XVII and XVIII, not shown). The storing and indicating of the count in the multi decade counters is obtained by sets of dual grid thyratrons which operate upon receipt of the end of scan signal so that the appropriate tubes are fired and actuate relays controlling the switches of a contact matrix, each decade count being represented by a combination of switches, the output leads energizing lamps or panels bearing the appropriate numbers or feeding the input of adding machines, punch card equipment or electric typewriters. The counters themselve are disabled whilst the printing or indicating devices are operated, e.g. by paralysing the input amplifier and shaper circuits.