Patent GB-497837-A (GB)
Title: Improvements in or relating to prepayment mechanisms particularly for use in connection with electricity meters
IPC: G07F15/04
Filed: 1937-05-24
Abstract: 497,837. Prepayment mechanism for meters. SANGAMO WESTON, Ltd., (formerly BRITISH SANGAMO CO., Ltd.), and WICKHAM, A. H. May 24, 1937, No. 14439. [Class 27] In a prepayment metering mechanism, particularly for controlling an electricity supply meter, operable by predetermined coins of different diameters such as pennies, sixpences, shillings and twelvesided threepenny pieces, the coins are inserted through a slot 14, Fig. 1, to a shoot 15. The coin or the first coin of a number inserted in immediate succession drops to a movable platform 16 and, by engaging a nose 17, presses aside a lever 18 to rock a shaft 20 having an arm 21 which closes contacts 22 in the leads 23 from a source of power to an electric driving motor 24. The motor 24 through gearing 27, 28 drives a shaft 29 which through gearing 35, 36, 37 drives two other parallel shafts 33, 34. The shaft 29 makes one complete revolution for each operative cycle of the mechanism and has a cam 32 controlling a set of contacts 30 wired in parallel with the contacts 22. The shafts 33, 34 also make one complete revolution per operative cycle. Cams 38, 39 on the shafts 29, 33 respectively are disposed on opposite sides of a coin chamber 40 which is moved thereby backwards and forwards in a direction normal to the plane of a coin in the chamber. The platform 16 is carried by one side wall 42 of the chamber so that the first coin in the shoot 15 after starting the mechanism drops to the chamber 40. The other side wall 41 carries a two-armed blade spring 44 with pins 45 which are moved through holes 46 in the shoot 15 to hold back the second coin of the succession until the first has been dealt with and the shafts 29, 33 made one revolution. The size of the shoot 15 is such that two of the smallest diameter coins when placed edge to edge are of a greater over-all dimension than a single coin of the largest diameter, so that the second of two such coins will be engaged by a pin 45. A cam 48 on the shaft 34 actuates an arm 49 connected by a spring 51 to a rockshaft 50 which has another arm 52 with an extension 53 working in slots 54 in the walls of the chamber 40. The coin therein resting on a platform 47 is moved against the rear wall 55 of the chamber and calipered by the extension 53. A third arm 56 on the shaft 50 moves a slide 60 to the rear to an extent corresponding to the diameter of the coin. This slide has notches corresponding to the diameters of the predetermined coins that may be used for prepayment, and, if one of these coins is in the chamber 40, an arm 61 is moved into a notch. The arm 61 is carried by a lever 69 fixed to a shaft 68a, Fig. 2, a second lever 68 loose on the shaft being pressed against the lever 69 by a spring 77 and having a recess engaging a conical projection 70 on the lever 69. The lever 68 is actuated by a cam 66 on the shaft 34 to cause the arm 61 to enter a notch. If a coin of wrong diameter is in the chamber 40, a notch does not register with the arm 61 so that the lever 69 remains stationary and the lever 68 is slid along the shaft 68a against the action of the spring 77 by the projection 70. The lever 68 engages a grooved collar 72 on a sleeve 73 slidable on a squaredportion of the shaft 34, a cam 80 on the sleeve actuating an extension 82 of a hinged deflector plate 83 which is rocked to deflect to a return shoot the wrong coin, when it leaves the chamber 40. Coins are forcibly ejected from the chamber 40 by an arm 78 on the shaft 33 working through a slot 79 in the side wall 41. The slide 60 also moves a pinion 63 along a square-section shaft 64, this pinion being thus brought into engagement with an appropriate section of a multi-section gear-wheel 65, the sections having teeth corresponding in number to the value of the coin that may be used. The gear-wheel 65 is loose on the shaft 34 and has a flange 76 provided with a stud 75 engaged and driven by a similar stud 74a on an end flange 74 of the sleeve 73. If a wrong coin is in the chamber 40, the sleeve 73 is moved along the shaft 34 to disengage the clutch teeth 74a, 75. The shaft 64 has a pinion 64a which sets forward the quantity-mechanism of the meter. The closing of the meter switch is effected from the shaft 29. In the event of the mechanism jamming during a cycle of operation, the current supply to the motor 24 is cut off by a lever 84, Fig. 4, which carries a gear-wheel 85 located between the pinions 27, 28, and which is rocked to open contacts 86 in the motor circuit. In another arrangement, Fig. 5, a bi-metal strip 89 surrounded by a heating coil 90 in the motor circuit normally engages a lever 92 to hold contacts 93 closed. In the event of jamming, the strip is heated by the coil 90 with consequent deflection which trips the lever 92 and opens the contacts 93. When the maximum number of coins has been inserted, a member 87, Fig. 1, connected with the quantity-mechanism opens contacts 88 in the circuit of the motor 24. Specifications 415,721 and 492,649 are referred to.