701,903. Coin freed apparatus: telephones. AUTELCA AKT.-GES. May 1, 1950 [May 6, 1949], No. 10709/50. Class 27 [Also in Group XXXIX] Coin action, weight: value received proportionate to value of coin. An impulse generator, particularly in a telephone prepayment box, generates a train of impulses determined by the diameter of a coin inserted in a common coin shoot under the control of a coin feeler which is moved by the coin to come under the control of one of several control members corresponding to different coins. From a coin tester (not shown) the coin 6 in Fig. 1 falls down a coin shoot 1 to rest on a transverse slide 26 in which position it tilts a lever 7a, 7b to position a follower at the end of the arm 7b against a cam 9a, 9b, 9c or 9d determined by the diameter of the coin. The move ment of the lever 7a, 7b also operates a mercury switch 13 in the circuit of the motor 14: the leads to the switch are taken to sliding contacts on the axis of rotation of the lever 7a, 7b and the switch. The motor 14 is connected through worm gearing 17, 18 to drive an impulse cam 19 which separates contacts 20 ten times in each revolution. The contacts 20 are normally shorted by further contacts (not shown in Fig. 1) which are opened, to permit the correct number of interruptions to be transmitted, by horizontal movement of the arm 7b, under the influence of the corresponding cam 9a, 9b, 9c or 9d. These four cams may be replaced by a single disc formed with four recessed cam paths and the lever 7a, 7b may be replaced by a sliding member. Coin discharging mechanism. Insertion of coin preventing and returning coin. The slide 26 is moved to close the lower end of the shoot 1 when a magnet 23 (V) is operated when the hand set is lifted. At the commencement of the coin impulses the magnet 23 (V) is de-energized to allow the coin to'fall to a position from which it may be discharged or refunded; when the magnet 23 (V) is released it also moves a slide 27 to divert any coin inserted before the end of the impulse transmission through a slit in the side of the shoot 1 normally closed by a slide 28 also controlled by the magnet. A second coin inserted so immediately as to pass the slide 27 is trapped between the side of the shoot and a projection'(not shown) which moves with the slide 27. Telephone apparatus. The motor 14 driving the impulse generator comprises a salient pole armature and a pair of mutually perpendicular stator coils M1, M2 (Fig. 5) controlled by make and break contacts m1, m2 opened and closed by a cam on the shaft of the motor, and is stopped at the end of the impulse transmission by the simultaneous closure of contacts v3, mk2, the latter being controlled by a cam on the shaft of the impulsing cams. When the hand set is lifted hook contacts HU1 extend earth over the b-wire to operate a calling relay (not shown) to start pre-selection. When set of coin relays has been seized a relay C (not shown) operates and completes a circuit: E-battery-winding II of relay A-winding II of relay X-c1-a wire- G-13-mi-and mik-transformer Ue-V-i HU2-mk1-G12-v1-Gl-HU1-s1-E for the magnet V which discharges the coin as described above. Contacts v1, which are latched open by an attachment on the handset until the hand-set is returned, break this circuit before the relay X can operate so that relay A makes over the resulting loop circuit to which the differential relay X does not respond. When a coin is inserted the mercury switch Q shorts winding I of relay X so that this relay can make in response to the current in its winding II and at x1 place its windings I and II in parallel to hold. The stator coil M1 is then energized in series with winding I of X and a resistor Wi from the earth on coin switch Q. The initial motion of the motor opens contacts mk1 to permit a relay S to operate in series with the coils M1, M2 so that contacts s1 short the coin switch Q which is released when the magnet V is shorted by contacts s2 to discharge the coin. Impulses generated by the contacts mi, mik then control the relay X until the impulse camshaft has made a complete revolution, when contacts mk2 and v3 stop the motor and contacts mk1 short the relay S: further coins may then be inserted. The relay A releases at the first coin impulse and does not remake until both windings are energized at the completion of the impulse train: after prepayment has been,made it serves to receive dialling impulses from the usual contacts k, i. When the coins are to be discharged, positive battery is applied to the a wire to operate magnet KM. If the coins are to be returned refund magnet RM is operated by positive battery applied to the b wire.