Patent GB-535619-A (GB)
Title: Improvements in or relating to apparatus for indicating and integrating maximum demands of a varying quantity
IPC: G01R11/60
Filed: 1939-10-12
Abstract: 535,619. Counting-apparatus. SANGAMO WESTON, Ltd. Oct. 12, 1939, No. 27788. Convention date, July 6. [Classes 106 (i) and 106 (iii)] [Also in Group XXXVI] Mechanism for indicating the maximum value that has occurred during any one of a number of successive measurements which comprises a member adapted to be moved during each measurement from an initial position to an extent dependent upon the value of such measurement and then to be re-set to its initial position prior to the next measurement, a second member adapted to be moved to an extent dependent upon the maximum movement of the first member during any one of a number of measuring movements of the latter, indicating means and means for moving said indicating means after the termination of the desired number of successive measurements so as to alter its reading by an amount governed by the extent of movement imparted to the second member during said measurements. In an electric watt hour meter the usual disc 27, through suitable gearing, drives pointers 11, 12, 13, 14 and shaft 46 at a speed depending on the rate at which the electricity is being consumed. A pinion 54 on shaft 46 drives gear 55 on shaft 56, Figs. 2A and 2B, and hence pinion 62 through a frictional coupling in the form of a spring spider 60 acting on gear 58. Pinion 62 lifts gear sector 73 and carries pusher arm 64 which, during a number of successive intervals, engages stud 66 on demand wheel 67 to rotate wheel 67 to an extent corresponding to the maximum demand in any interval, say half an hour, in the period, the movement of wheel 67 being indicated by pointer 36. The movement of demand wheel 67 is transmitted through gears 135, 132, 130, 129 and spider spring 128 to staff 121 and through reduction gearing to staffs 122, 123. The pointers 31, 32, 33, 34 meanwhile remain stationary at their setting from the previous period-end. At the end of an interval, cams 100, 101 driven by a synchronous motor 91 operate levers 104, 105 to rock and shortly afterwards restore plate 49 in which one end 48 of shaft 46 is journalled. This causes a short disconnection of the pinion 54 and gear 55, during which time counter weights 76 restore gear sector 73, pinion 62 and pusher arm 64 to initial positions. determined by pusher arm 64 abutting against lever 78, while demand wheel 67 and pointer 36 remain stationary. At the end of a period, manual reset arm 39 is rotated counter-clockwise through one revolution, heart cam 167 on shaft 166 accurately positioning the arm 39 at the end of the revolution, and operating lever 169 to rock lever 174, Figs. 2A and 2B, to interpose the end of spring 163 between the teeth of gear 162 to block staffs 121, 122, 123, while the end 178 of lever 174 rocks plate 49 to disconnect pinion 54 from gear 55, the upward position of lever 174 being maintained for about one third of an interval, say ten minutes, by the frictional engagement of shaft 99 and cam surface 181. These operations take place during the initial movement of arm 39, the later movement causing the end 207 of an arm on shaft 166 to engage a lever 205 to rotate gear sector 197 which rotates gear 68 to set demand wheel 67, indicator 36 and pusher arm 64 to initial positions, compensation being provided for backlash in the gear train between demand wheel 67 and the blocked gear 162. At the end and during the initial movement of arm 39, a spring pawl 187 carried by disc 190 on shaft 166 is disengaged from the teeth 186 of a hub 185 by a collar 191 on a stationary shaft 192. After the staffs 121, 122, 123 have been blocked, pawl 187 engages the next tooth on hub 185 to drive gear 155 which drives gears 154, 146, 148, 150 which advance pointers 32, 33, 34 through frictional engagement into positions corresponding to their respective staffs 121, 122, 123 the positions being determined by pawl 141, and ratchet wheel 139 for pointer 32, and stops 144 and fingers 143 for pointers 33, 34. Pointer 31 is advanced with pointer 32 but at a higher speed by pinion 152 and gear 151. The difference between the old and new readings of pointers 31, 32, 33, 34 gives the maximum demand in any interval in the preceding period. For testing purposes, the pointers 31, 32, 33, 34, can be reset to their previous reading by rotation of member 41 by a screwdriver, pinion 211 being pressed against the action of spring 210 into engagement with gear 159.