515,223. Prepayment mechanism for meters. SWITCHGEAR & METERS, Ltd., and ANGOLD, A. W. May 26, 1938, Nos. 15769/38 and 2461/39. [Class 27] Coin action, multiple-coin with delivery proportionate to value of coin; coin-slit closing-devices. - In prepayment mechanism for meters having a caliper for gauging. the diameter of the coin whereby crediting mechanism is set forward by an appropriate amount, a member normally obstructing the entry of coins to the coin pocket is moved to permit coin insertion and, when so moved, sets the caliper in readiness to gauge the coin and locks the prepayment mechanism, the return of the member to normal position allowing the caliper to effect the gauging and freeing the prepayment mechanism so that a prepayment handle can be operated to advance it. The construction shown has an outer coin-pocket 11 behind an insertion slot 9 and an inner pocket 28 in which the coin is gauged by the inturned end 34 of a caliper 31 arranged to slide on a side wall of the pocket. The means normally preventing insertion of a coin comprises a plate 14 arranged to slide behind the insertion slot 9. To insert a coin, the plate 14 is lowered by depressing a finger piece 17 secured thereto, whereupon a cam 18, also secured to the plate, rocks a pivoted lever 20 which, through a pin-and-slot connection 26. raises the caliper 34 in readiness for gauging the coin. On releasing the finger piece 17, the plate 14 is returned by a spring and a cam 16 projecting from its rear into the outer pocket thrusts the coin into the inner pocket 28. Simultaneously cam 18 releases lever 20 which is returned by a spring 23 and lowers the caliper 31 until its inturned end 34 contacts with and is arrested by the upper edge of the coin, its ultimate position thus being determined by the diameter of the coin. The caliper is connected by a bell-crank 49 to a multi-tooth pinion 47 which it displaces along a square shaft 55 to bring the section appropriate to the coin into mesh with a pinion 47 which is connected with the quantity mechanism through the gearing described in Specification 515,245. Upon turning shaft 55 by means of an external handle the quantity mechanism is set forward the appropriate amount. To prevent rotation of the shaft 55 with coins of incorrect diameter a lug 67 on the caliper 31 works in an approximately radial slot 64 in a disc 52 secured to the shaft and registers with annular clearance grooves in the disc only with correct coins. The shaft 55 is normally locked by a catch 68 engaging a notch in the disc 62, the catch being operated to release the disc by depression of the base of the coin pocket when depressed by a coin whilst being gauged. The base of the coin pocket is ultimately displaced to release the coin by a cam on the shaft 55. Fig. 5 shows the mechanism for setting the supply switch. A-roller cam 89 on shaft 55 turns an arm 90 anti-clockwise, arm 90 engaging and turning clockwise a lever 93. Arm 90 ultimately slips past a pawl 92 on lever 93 which thereupon springs sharply back under the action of a spring 95, and, by means of a roller 97, rocks a contact member 99 into its circuitclosing position where it is locked by catch mechanism (fig. 12, not shown) controlled by.the quantity mechanism. If,.however, the switch is already closed, a .projection 13 on the contact member 99 rocks a lever 114 which prevents the return of arm 90 to a position to be actuated by the roller cam 89. Other details of the complete mechanism are as described in Specification 515,240. According to the first provisional Specification the coin insertion slot is closed by a flap pivoted at its edge beneath the slot, this flap having a cam which actuates the caliper. The coin is inserted directly into the pocket where it is gauged by the caliper. Casings.-The actuating handle is carried by the front cover of the casing, and is connected with shaft 55 by means of a dog clutch so that the cover, with the handle, can be removed..