1,068,481. Checking cash. NATIONAL REJECTORS Inc. Jan. 29, 1965, No. 4087/65. Heading G4T. A device for detecting authentic currency notes engraved with metallic ink comprises a magnetic head (244), Fig. 3 (not shown), a light-sensitive element (770) (Fig. 3, not shown), an area to which an acceptable note is moved, mechanism for moving a note to said area only if the magnetic head (244) and light-sensitive element (770) provide first and second validating signals respectively and means for retrieving the note if it is not accepted. As shown at the rear 42 of the device motor 188 through shafting and gearing, Fig. 10 (not shown), drives pulley wheels 164 and 180 synchronously. Pulley timing belts 270 and 272 driven by said pulley 164 and 180, also pass over pulleys 204 and 194 adjacent the front 36 of the device. Along the length of the path traversed by the notes, i.e. between platens 94 and (50) (Fig. 3) are a series of actuators 276, (284), 288, (292), 300 and (296) which are associated with switches 752, (282), (286), (290), (736) and (734) respectively (see Fig. 17, not shown). At rest, pivot 202 and turning belt pulleys 204 are in a raised position to facilitate ease of entering a note through slot (38) and between pulley belts 270 and 272 (Fig. 5, not shown), and gate (370) is also raised to align opening (374) with opening (38) (Fig. 15, not shown). At the same time, roller (326) (Fig. 3, not shown) is held out of engagement with magnetic head (244). The electrical components will be in the positions illustrated by Figs. 19-23 (not shown), and current will be flowing through lamp (762) and light-sensitive element (770). On placing a note through opening (38), a patron will press button (340) (Fig. 1, not shown), thereby energizing relay coil (528). As current flows through resistor (538) and coil (528), condenser (536) will become charged. When the patron releases the button, the condenser will discharge energizing coil (528) for a short but adequate period of time. Energization of coil (528) shifts contact (532) into engagement with contact (530) and energizes solenoid 230 which retracts plunger 228, rotating rocker arm 224 in a clockwise direction and through linkage 214, 216, 207, (206) lowers pulleys 204 and causes the leading edges of the timing belts 270, 272 to engage the leading edge of the note. As rod 214 moves forwardly it moves actuator (234) to close switch (232) (Fig. 3, not shown), and complete a circuit which starts motor 188 rotating in a direction such as to cause the timing belts to move the note towards the rear of the device. Since the time constant for condenser (536) and resistor (538) is less than 1 second noteactuated switch 752 provides a further connection for the solenoid 230 and the motor 188. The note then engages actuator (284) of switch (282) which completes a circuit to energize solenoid 330 and retract plunger 332. Retraction of plunger 332 moves linkage 334, 328, 323, (322) and (324) (Fig. 3, not shown), to move soft-faced roller (326) (Fig. 3, not shown) to engage the note and to press the upper face of the note against the magnetic head (244). The roller (326) engages the note with sufficient force to raise the head (244) against the force of spring (246). The note will be moving at a set speed across the air gap of the magnetic head (244) and will generate voltage variations in the coil of the magnetic head, which are amplified by transistors (870) and (884) (Fig. 21, not shown). The resulting signal suitably limited by the triodes (904) and (914) are then supplied to a resonant circuit including capacitors (922) and (924). Where those voltage variations are derived from an authentic note, two controlled voltage growths will be experienced in the resonant circuit, each growth will cause thyratron (928) to become conductive which will allow relay coil (428) to be energized and contacts (442) to close. This results in the eventual energizing of the solenoid (344) and retraction of plunger (346) which through linkage (350), (352), (355), (354), (353) will release gate (370) (Figs. 14 and 15, not shown). If no thread is attached to the note the gate will be able to move down far enough to operate switch (362). The note will continue to move rearwardly and its leading edge will engage actuators 288, (292) of switches 286, (290) which actuate maintaining circuits. The note eventually contacts actuators (296) and 300 whereupon a circuit is made, e.g. to a vending machine. The note eventually-passes through the device via a slot in back plate 42. When the note leaves actuators (296), 300 all electrical components will return to positions shown by Figs. 19-23. If the note was not authentic the coil (428) would not have received two validating signals and solenoid (344) would not be energized. Also contacts (522) would have been unable to open and when the noteoperated switch (290) a circuit would be completed which would reverse the connections to the main winding of the motor 188 and return the note to opening 38. Similarly, since the note reflects light, voltages are formed in lightsensitive element (770) which for an authentic note will cause thyratron (1186) to become conductive. This allows relay (818) to be energized, which in turn allows relay (830) to be energized which will close contacts (834), (836), contacts (834) completing a holding circuit for that relay. Thus, if the inserted note does not coact with the magnetic head (244) to provide voltage variations which produce validating signals and if the note does not coact with light-sensitive element (770) to energize relay coil (818) the currency detector device will halt the note almost immediately after the leading edge of the note engages actuator (292) of switch (290). The switch (290) coacts with contacts (524) adjacent coil (520) to provide an early sensing of the receipt or non-receipt of signals from thyratrons (928) and (1186).