GB1405936A - Coin selector - Google Patents

Abstract

1405936 Testing coins MARS Inc 9 Aug 1972 [16 Aug 1971] 37227/72 Heading G4V A coin tester comprises a coin passageway 12, first and second coin presence sensors spaced apart in the direction of movement of the coin, means 20 for generating a magnetic field upstream of at least one of the sensors, means for measuring time intervals dependent on coin presence sensing by said sensors and means for comparing the measured time intervals with predetermined standards. In the four denomination tester described there are two secondary sensors 44, 46, preferably phototransistors, located upstream of a primary sensor 42. The sensors are arranged so that a 50 c piece will obscure all three sensors simultaneously, a 25 c piece obscure all sensors but only sensors 42, 46 simultaneously, a 5 c piece obscure sensors 42, 46 simultaneously but not sensor 44 at all and a 10 c piece obscure only sensors 42, 46 but not simultaneously. Obscuration of sensor 44 sets a flip-flop 56, reset by coin arrival sensor 28, to apply an input signal on lead 66 to gates 48, 50 associated with 50 c and 25 c pieces respectively the other inputs to these gates being from sensors 42, 44 and 46 either directly or via inverters. The other output 76 of flip-flop 56 is applied as an input to gates 52, 54 associated with 5 c and 10 c pieces respectively these gates also being connected to the sensors and having another input 84, 86 from a flip-flop 58 which is set when sensor 46 is obscured indicating that the coin is of a minimum permissible diameter. According to the diameter of the coin the input conditions at one or none of the gates will be met, the time interval during which such conditions are met being dependent on the diameter and velocity (and hence due to the eddy current braking effect of magnet 20 on the electromagnetic properties) of the coin. The outputs of gates 48, 50, 52 and 54 are connected to gate 94 and also as enabling inputs to respective flip-flops 102, 104, 108 and 106. The output of gate 94 acts via gate 116 to allow pulses from clock generator 114 to pass to counter 112 which is connected to a decoder 110 having four pairs of outputs, each pair corresponding to the lower and upper expected count levels for one denomination of coin and being connected as enabling and disabling inputs respectively to the appropriate flip-flop 102 to 108. If the coin is acceptable with regard to its diameter and velocity the corresponding flipflop will be set, the outputs of the flip-flops being connected to a coin acceptor 122 and a pulsemaker 124 that provides a number of pulses corresponding to the denomination of coin to an accumulator 126. The pulsemaker is blocked until the coin no longer obscures sensor 42 thus ensuring that the velocity examination is complete and may also be blocked by a high price signal on lead 132 from the accumulator, a similar high price lead 134 serving to render the acceptor 122 inoperative. The secondary sensors may be located downstream of the primary sensor.