Patent GB-955501-A (GB)
Title: Weighing apparatus
IPC: G01G23/18
Filed: 1962-02-26
Abstract: 955,501. Weighing apparatus. TOLEDO SCALE CORPORATJON. Feb. 26, 1962 [Feb. 28, 1961], No. 7378/62. Heading G1W. [Also in Division G4] Weighing apparatus is associated with a system which reads out the weight automatically when the weigh beam is stationary, any movement of the weigh beam operating control means to terminate the cycle of the read-out system and to reset it to start a new cycle. As shown schematically in Figs. I and II the apparatus includes a weighing mechanism 91, a motion detector 92 and a photo-electric scanner 94. An associated computer includes a pulseshaper 97, a multiplier 98, weight counter 99, and valve counter 104. A read-out printer 107 is associated with a check circuit 100. The photocell is connected to a motion-detector relay wnich prevents operation of the scanner until the scale mechanism comes to rest. The pulses from the photo-cell are amplified and applied to multiplier 98 which is adjusted by a price-selector switchboard 103. Whenever the scale moves to a new weight value, there is a sequence of first motion and then no motion. The scanner does not respond to the motion signal but begins its cycle when the motion stops. Each sequence of motion and then no motion causes the scanner to go through one cycle of reading the scale and feeding the weight information to the computer. If scale motion occurs during this scanning cycle, the weight and price information stored in the computer is in error and should not be read out. An error circuit is activated which prevents operation of the readout mechanism and automatically starts a new scan at the completion of the false scan, or when the motion stops if the motion continues after the false scan is completed. Each scan causes the computer to store a new set of weight and value information. The scanner provides a reset pulse to reset the computer at the beginning of each scan and an interlock signal to prevent input signals to the computer, except during scan. The readout mechanism is internally interlocked so that when it receives a signal to make a new readout it goes through its operating cycle without interruption. Two conditions are necessary to start a readout cycle. A momentary contact switch on a ticket dispenser must have been operated and a new scan must have been completed since the previous readout. A memory circuit is provided to prepare the readout mechanism after the scan so that it can be activated by the ticket switch. Operation of the readout resets the memory circuit so that two successive readouts cannot be made without a scanning cycle in between. If the ticket switch is operated before a new scan it also sets up the memory circuit so that a readout will automatically occur after the next scan. Interlock contacts are provided on the readout to prevent a scanning cycle during readout. Each completed readout cycle starts a printing cycle unless the "no print" of "off" position of the printer mode switch is operated. Operating the "continuous" switch locks the readout and sets up the printer circuitry so that duplicate tickets are printed on a continuous cycle basis until the printer mode switch is turned "off". Price and commodity interlocks are provided so that their price setting knobs must be moved when the commodity plate is changed. Likewise, the commodity plate must be moved in and out or replaced if price setting knobs are moved. Error lights are provided to indicate certain types of sequence failures. Weighing and scanning apparatus. The weighing mechanism 91 includes a scale chart having two sections; a weight portion graduated in decimals of a pound and a separate column of lines used in conjunction with the motion detector. The weight portion of the scale chart is projected for visual indication. A scanner shutter or mask is mounted on a scale chart lever. When a load is applied to the weighing platform the shutter moves with the chart lever, exposing one line on the scanner chart for each unit of pounds of load. Motion of the scale mechanism causes interruptions or variations in light on the photo-electric cell, causing it to produce an electrical pulse for each interruption or variation in light. When the scale mechanism comes to rest, the motion detector relay allows the scanner 94 to operate and it converts the travel of the scale lever system to electronic pulses. These pulses are coupled to the computer to provide weight and value computations. A weigh beam is fulcrumed so that a load placed on a platform is balanced by springs, not shown. Sequential operation. The timing diagram, Fig. VI, has reference to circuits, Figs. III, IV, V, which include indicating and interlocking means controlled by the interaction of relays in conventional manner and illustrates in part the main steps in the sequential operation of the electronic computing scale. These steps are: (1) check circuit output relay K11 and time delay relay K12 energized. Main driving motor, computer and readout fan motors started and scanner and scale projection lamps illuminated. (2) Activator heat element turned on. (3) Paper supply switches operated on insertion of ticket supply in printer, the supply to the drive and scanner motors being interrupted while the door of the printer housing is open. (4) Printer set for mode of operation required ("off", "on", "demand" or "continuous") regular operation corresponding to the "on" position. (5) Commodity plate or knob inserted or operated, in connection with the price and commodity interlock. (6) Change price relay K1 energized, energizing price and name relay K3 through contacts of K1 and of change commodity relay K2 and thus extinguishing set price and name lamp. (7) Tare-set switch operated. (8) Timedelay relay K12 drops out and causes illumination of ready lamp. (9) Commodity placed on weighing pan. Motion detector relay K10 energized, extinguishing ready lamp and resulting in energization of start cycle relay K4 and de-energization of relays K1, K2. (10) Relay K10 de-energized at end of movement of weighing pan. Scanner control relay K5 and scanner start relay K6 energized, resulting in the scanner motor being started for movement in the forward direction and in the provision of reset pulses to the computer circuits. (11) Scanner gate switch allows pulses to shaper gate circuit and seal-in circuit is established for relay K6. (12) Scanner gate switch operated as scanner reaches "out" position,thus energizing wheel release relay K7 of printer. Relay K7 also energizes latch release solenoid LRS and deenergizes relay K5, resulting in reversal of the travel of the scanner motor and illumination of the ready lamp to show that the scanning portion of the electronic computing scale is ready for another weighing operation. (13) The sensing bar of the mechanical readout wheel leaves its "home" position and operates switches to turn off the gate to the check circuit and to turn off trigger circuit power. (14) The sensing bar reaches its "out" position and operates a switch SW2 (not shown) whereby cycle complete relay K8 is energized, following which relays K4, K7 and solenoids LRS are de-energized. (15) The sensing bar leaves the "out" position, removing operation of the switch SW2. (16) The scanner leaves the "out" position, removing operation of the scanner out switch and scanner gate switch. (17) The sensing bar operates a middle switch, thereby restoring power to the trigger circuit. The indicator wheels stop moving. (18) The indicator wheels check electrically and the sensing bar leaves the "check" position. The check circuit relay K11 is de-energized, whereby the mechanical check solenoid MCS is energized. (19) The indicator wheels check mechanically and the sensing bar returns to its "home" position, opening the gate of the check circuit and thereby energizing the check circuit relay K11, which deenergizes the solenoid MCS. Print solenoid PS is also energized. (20) On the printer carriage leaving its "home" position, print solenoid PS is deenergized. Also, relay K8 is de-energized and the take label relay K9 is energized, thereby lighting a "take label" lamp. (21) The scanner returns to "home" position, de-energizing relay K6, resulting in the scanner motor stopping and reset pulses being removed from the computer and pulses being reset to the check circuit. (22) A label is printed, cut off and delivered and the printer carriage returns to the "home" position. (23) The commodity is removed from the weighing pan and the activator operates switches whereby the relay K9 is deenergized and the "take-label" lamp extinguished. (24) The label is removed and placed on the package and the activator is released. Specifications 833,362, 886,876, 886, 877, and U.S.A. Specification 2,759,672 are referred to.