361,758. Counting-apparatus. LANDIS ET GYR SOC. ANON., 1, Hofstrasse, Zug, Switzerland. March 6, 1931, No. 7013. Convention date, March 8, 1930. [Class 106 (i).] Associated counters; electric counters.-The transmitted measurements of exported and imported energy from a number of generating stations are separately summated, and the excess of total imported or exported energy is registered by forming the difference of the two summated measurements. At each generating station an energy meter c, Fig. 1, measuring the exported energy, and a second energy meter d, measuring the imported energy, are provided. The meters c, d have means for preventing reverse rotation and are provided with contacts a, b connected to pilot lines e, f, leading to a central control station. At this station there are two separate receiving apparatus g, h, each containing an impulse summator meter j, k, and a recording maximum demand meter. Each summator meter j, k has two groups of relays o, p<1>, o<1>, p, of which the groups o, o<1> receive impulses from the exported energy meters c and the groups p<1>, p from the imported energy meters d. The receiving apparatus g, which records the excess of energy exported, is shown diagrammatically in Fig. 2, the receiving apparatus h being similar but arranged to record excess of energy imported. The two sets of relays o, p<1> are arranged on opposite sides of a bracket 1. Each of the armatures 4, 5 of the relays o, p<1> has a feed pawl 8, 9 engaging a ratchet wheel 6, 7 and operated by a separate tappet wheel 12, 13 having a projection 10, 11 and mounted on a continuously rotating shaft 14, 15. The feed wheels 12, 13 corresponding to each group of relays o, p<1> are staggered relatively to one another on their spindles so that correct actuation is ensured when more than one relay of the group are simultaneously actuated. The subtraction mechanism contains a differential gear 20, the sun wheel 21 of which is driven through a pinion 23 and worm 22 from a gear wheel 18 driven by the relay o. The second sun wheel 24 is driven in the opposite direction through a pinion 26 and worm 25 from a gear wheel 19 driven by the relay p<1>. The spindle 28 of the differential gear 20, carrying the arbor of the planet wheel 27, drives, through gearing 29, 30, 40, a gear wheel 41 which is loosely mounted on an arbor 42. A pin 43 on the gear wheel 44 engages a driving arm 44 fixed to the arbor 42. A gear wheel 45 is connected to the arbor 42 through a friction spring 47 and engages a gear wheel 46, which is connected to its arbor 49 through a friction spring 48 and carries a bush 50 with a driving arm 51. This engages a driving pin 52 carried by a gear wheel 54 which is connected to the arbor 49 by the pressure of a spring 53. A return spring 56 is connected at one end to the frame 58 and at the other end to a collar 60 fixed to the arbor 49. A grooved pulley 62, fixed to the arbor 49, is connected by means of a tension member 63 with another grooved pulley 64 and is attached to a cylinder 66 guided in a tube 65, through a slot in which projects a recording arm 68 attached to the cylinder. The pulley 62 is provided with a pin 69, which in the zero position of the recording arm 68 rests against a stop 70. An arbor 71 carrying a gear wheel 72 serves for resetting and is driven by a Ferraris motor which is switched in by clockwork at the end of each predetermined period of time. The clockwork also controls a lever arm 73 mounted on the tube 65 so that at the end of each predetermined period the recording arm 68 is pressed against the chart 74. Assuming that energy is being exported, impulses from the contacts a on the meters c energize the corresponding relay magnets o, the armatures 4 of which are attracted and remain adhering to the polepieces after the impulses have been given, owing to the remanence of the iron. The corresponding projection 10 on the tappet wheel 12 then engages the armature 4, removes it from the polepiece, and rotates the ratchet wheel 6, and consequently the gear wheel 18, through a small angle. The pulley 62 is thereby rotated in a clockwise direction and moves the recording arm 68 further to the right. Also, by means of the clutch 51, 52, the return spring 56 is further wound up. If there is a change from exporting to importing energy, the relays p<1> are operated and cause motion of the gearing in the reverse direction. The stored-up energy of the spring 56 then causes the driving arm 44 to remain in engagement with the pin 43 and the arbor 49 and pulley 62 are rotated in a counterclockwise direction, thereby moving the recording arm 68 to the left. If the energy imported exceeds that previously exported, the spring 56 is brought back to its initial stress, the recording arm 68 is returned to its initial position, and the pin 69 engages the stop 70. Further importing of energy causes the driving pin 43 to move away from the arm 44, which retains its position on account of the engagement between the pin 69 and stop 70. The angle between the pin 43 and arm 44 corresponds to the magnitude of the excess of the imported energy registered by the receiving apparatus h, Fig. 1. If energy is again exported, the pin 43 moves towards the arm 44 which it again engages and moves when the exported energy exceeds the previous excess of imported energy. At the end of a predetermined period, the shaft 71 and gear wheel 72 are rotated in a counterclockwise direction, thereby restoring the spring 56 to its initial stress and returning the recording arm 68 to its zero position. Owing to the pin 69 engaging the stop 70, and the gear wheel 41 being locked by the worms 22, 25, further motion of the resetting motor causes the gear wheels 54. 46, 45 to turn idly on their arbors, overcoming the friction of the springs 53, 48, 47.