| 摘要 |
<p>1312195 Coin testing apparatus MARS Inc 22 Nov 1971 [23 Nov 1970] 54173/71 Heading G4V In a coin tester that examines the velocities of coins after they have passed through a magnetic field, the velocity examining means comprises first and second coin sensors 550, 552, Fig. 2, spaced apart along a coin passageway, the first sensor being connected to a monostable 554 to produce an output signal of predetermined duration when a coin is sensed by the first sensor, the monostable 554 being connected to a further monostable 556 which produces an output of predetermined duration on termination of the output from monostable 554, a first gate 558 responsive to concurrent signals from the second sensor 552 and the monostable 554 and a second gate 562 responsive to concurrent signals from the second sensor and monostable 556. In the embodiments described the output of gate 558 sets a flip-flop 560 to apply a blocking signal to gate 562 which will thus only give an output, to indicate a genuine coin, if the sensor 552 senses a coin whilst monostable 556 is in operation. Monostable 554 sets a maximum coin velocity (i.e. minimum time between sensors) and monostable 556 determines an acceptable range of velocities. The sensors are preferably photo-electric detectors. A magnetic coin scavenger may be provided (Fig. 1, not shown) upstream of the magnet (23) together with a retractable stop for initially bringing the coins to rest before passage past the magnet. A platform (24) normally directs coins received from passageway (16) to a reject shoot (27) but is retracted by a signal from gate 562 to allow coins to fall into an acceptance shoot (26). Multidenominational tester.-In a tester for 1d, 3d, 6d and 1/- coins the velocity examining means, Fig. 5, comprises a common first sensor 502 with second sensors 503 for 1d coins, 504 for 3d coins and 507 for both 6d and 1/- coins (as the velocities of authentic coins of these two denominations should be virtually identical). The second sensors 503, 504, 507 are connected to respective AND gates 616, 615, 614 that receive at their other inputs a signal from monostable 611 connected to the first sensor 502, and have their respective outputs connected to flip-flops 619, 618, and 617. On termination of the output from monostable 611 two further monostables 612, 613 are operated to produce signals of durations determining an acceptable velocity range for 6d and 1/- coins and 1d and 3d coins respectively. The monostables 612, 613 are connected to AND gates 620, 621, 622 which receive at their other inputs outputs from flipflops 617, 618, 619 and signals from the sensors 507, 504, 503, and have their outputs connected to flip-flops 623, 624 and 625 that are accordingly set on the passage of authentic 6d and 1/- coins, 3d coins and 1d coins respectively. Measuring chordal dimensions.-As a further test a chordal dimension of a coin is examined to determine whether it lies within an acceptable range by means of a primary sensor 510 and a pair of secondary sensors for each coin denomination (e.g. 508, 509 for a 6d coin, see Fig. 4, not shown) only one of which will be obscured by a coin of acceptable size when the leading edge of the coin reaches sensor 510. Signals from sensor 510, the pair of secondary sensors (one signal inverted) and the corresponding flip-flop 623 to 625 are fed to respective AND gates 602, 604, 606 and 608 which give an output when both the velocity and chordal dimension criteria are met by a coin, correspondingly setting flipflops 603, 605, 607 and 609 which act through an OR gate 610 to energize a solenoid for withdrawing the platform (24) from the coin shoot.</p> |
