Patent GB-1375601-A (GB)
IPC: G07D9/00
Filed: 1972-02-25
Abstract: 1375601 Testing coins MARS Inc 25 Feb 1972 [3 March 1971] 8894/72 Addition to 1319126 Heading G4V The coin tester of the parent Specification 1,319,126 has been modified in various respects. In a first embodiment, Fig. 1, an inserted coin is brought to rest against a stop 128 by an inclined portion 124 of coin support track 122 before linear motor impeller 80 is energized to impel the coin past velocity and chordal dimension examination means which comprise coin detectors, such as photo-electric devices, 132, 133 and 135. Detectors 132 and 135 are connected to set and reset flip-flop 136 the output of which controls gate 138 to allow the passage of pulses from oscillator 140 to counter 144, the number of pulses counted is therefore inversely proportional to the velocity of the coin which is a function of the coin's electrical conductivity, density, weight and diameter. A flip-flop 150 is connected to a counter decoding matrix 146 such that is set at lower acceptable count and reset at the higher acceptable count for a particular denomination of coin. The output of flip-flop 150 is fed to AND gate 139 which receives at its other inputs signals from detectors 132, 133 and 135, which are arranged to determine whether, when the leading edge of the coin first reaches detector, the trailing edge of the coin lies between detectors 132 and 135. If the velocity and chordal dimension of the coin is acceptable a flip-flop 141 is set. For multi denomination testing corresponding pairs of detectors such as 132, 135, a flip-flop 150 suitably connected to the decoding matrix 146, an AND gate 139 and flip-flop 146 are provided for each denomination. To take account of variations in the A.C. supply for energizing the linear motor 80 and hence the velocity imported to the coins a circuit 152 is provided to vary the pulse frequency of oscillator 140 accordingly. A circuit for energizing the linear motor (Fig. 2, not shown) enables the direction of the travelling magnetic field to be reversed in which case the inclined portion 124 of the coin track may be dispensed with, the coin being first urged against the stop 128 by the motor which after a delay is then energized to impel the coin away from the stop. A cirduit for energizing the motor from a D.C. supply (Figs. 3, 3A and 3B, not shown) also includes means for maintaining the current in the impeller coils constant as their temperature rises. To cut down on the length of the coin track the coin detectors 132, 133 may be included in the spacer between adjacent polepieces of the linear motor (Fig. 4, not shown). In another embodiment, Fig. 6, an inserted coin is impelled away from retractable stop 232 by the impeller 222 past detectors 218 to a sloped portion of track 230. On return of the coin the impeller 222 is selectively energized by logic circuitry associated with the detectors to impel the coin at a prescribed velocity past the now retracted stop 232 and into a selected shoot 227, 228 or 229 according to its denomination and acceptability. A similar embodiment (Fig. 5, not shown) uses two spaced impellers, one before and one after the coin detectors, the second impeller (226) directing the coin into the appropriate shoot. In a further embodiment, Fig. 7, an initial separation of inserted coins is effected by impeller 276 adjacent sloping coin track 270, the coins either passing from the bottom or top of the track 270 according to their properties, and being received on further tracks 272 or 274 with which are associated respective impellers 278 and 280. The coins then pass from the respective second track into upper or lower shoots 294 according to the velocity imparted to them by the combination of the impeller and sloping track. In order to increase the separation of coins of different diameters but similar material a tapered impeller or an impeller inclined to the coin track may be used (Figs. 8 and 9, not shown).