Patent GB-1167446-A (GB)
Title: Multiple-Selection Dispensing or Vending Machine
IPC: G07F9/00
Filed: 1968-01-24
Abstract: 1,167,446. Vending machine. VENDO CO. 24 Jan., 1968 [16 Feb., 1967], No. 3729/68. Heading G4V. [Also in Division H3] A multiple selection vending machine comprises a plurality of article dispensers, and proximity sensing means associated with each dispenser and arranged to actuate a respective dispenser upon sensing the proximity of a customer. General operation.-A multipleselection coin - operated vending machine comprises a conductive selector plate 14, associated with each article dispenser and arranged within a circuit, Fig. 5, to cause a net D.C. signal to be obtained from the output of a sinusoidal oscillator when the effective capacitance of the plate is increased by the proximity of a customer's hand, whereupon the D.C. signal is fed to an AND gate, which fires if a signal indicating the receipt of the correct money is being received from a totalizer, and triggers a vending timer. Article selection.-A customer selects an article by placing a hand adjacent one of four circular conductive selector plates 14, which are situated below their respective compartments. A high frequency (e.g. 500 KHz) sinusoidal oscillator 22 provides a signal for each circuit 20, Figs. 2 and 5, where two circuit legs carry alternate half-cycles which are averaged by a grounded capacitor at a point 104. An adjustable earthed capacitor 110 serves to neutralize the effect of the natural capacitance of plate 14. The increased effective capacitance of plate 14 caused by the proximity of a hand produces an averaged D.C. signal at point 104, which is applied to one of the AND gates 50, 52, 54 or 56. Totalizer; price setting. Fig. 2.-Coin switches disposed along coin tracks communicate with a solid state or stepper-relay-type totalizer which provides a signal corresponding to a total of 10, 15 and 20 on lines 28, 30 and 32 respectively. There are initially no input signals to a NOR gate 98, so the AND gates 34, 36 and 38 pass a signal from the totalizer to rotary price setting switches 42, 44, 46 and 48, and switches set to an activated price line will pass a signal to their corresponding AND gates 50, 52, 54 and 56. An AND gate having a " correct money " signal and also a signal from the appropriate article selector 20 will fire and pass a signal to the interlock, 58 and Fig. 4. Interlock, Fig. 4.-Output signals from gates 50, 52, 54 and 56 are applied to the control gates 114a, 116a, 118a and 120a of SCR's 114, 116, 118 and 120, respectively. Upon receipt of a first signal at the interlock the corresponding SCR will conduct, and its anode will fall to near earth potential, causing circuitry (not described) connected to a lead 124 to deliver a suitable signal to a corresponding lead 74, 76, 78 or 80. Any further signals received will not cause their corresponding SCR's to conduct since the first signal transmits a negative transient through capacitors 122 to the anodes of the remaining SCR's, preventing conduction. Article-dispenser; coin return.-A signal from the interlock 58, Fig. 2, starts a timer 60, which may be of the RC electronic type. A coin-return device 70 comprises a gate in an escrow, and resets the totalizer when operated. The timer 60 first causes the escrow 66 to accept held coins and simultaneously operates a device 68 to prevent the coin-return device 70 from being actuated. After a time lag to allow the interlock circuitry to stabilize the timer 60 produces a vend pulse along a line 62 to AND gates 82, 84, 86 and 88, where the AND gate having also a signal from the interlock fires, and thereby actuates a vend solenoid. The presence of a signal on one of the lines 74, 76, 78, 80 causes NOR gate 98 to have a zero output, thus preventing the transmission of further coin value signals from the totalizer. The timer 60 finally produces a " reset " pulse along a line 64 to the totalizer, and also to the interlock, 58 and Fig. 4, in the form of a negative pulse to the anodes of the SCR'S.