GB548817A - An uncoupling device for use on standard electricity meters - Google Patents

Abstract

548,817. Supply meters; calibrating meters. LANDIS & GYR SOC. ANON. Oct. 17, 1941, No. 13368. Convention date, Oct. 21, 1940. [Class 37] An uncoupling device for a standard meter for use in calibration is operated by means of two electromagnets which are arranged so as to be alternately connected to a coil mounted on the core of the driving magnet and act on the coupling between the driving and counting mechanism by means of armatures alternately coming into a locking or engaging relation with the coupling mechanism. The pointers 6 of the counting mechanism are connected through gearing 7 to the upper part 8 of the shaft of the driving disc 2. The lower part 9 of this shaft is connected with the upper part 8 through a coupling 10, 11, the member 10 of which is axially movable and normally held in engagement with the member 11 by a spring 13. The armature 15 of an electromagnet 16 is pivoted at 14 and has a projection 17 engaging the upper side of a flange 12 on the member 10. An insulating pin 18 carried by the armature 15 engages the spring part of a switch 19 in series with a second electromagnet 20 having an armature 21 which is pivoted at 22 and has an extension 23 engaging the spring part of a switch 24 in series with the electromagnet 16. One end of each of the electromagnet coils 16, 20 is connected to a tapping on the voltage coil 3 of the meter, a second tapping on which is connected to the movable arm 31 of a change-over switch 28, the contacts 27, 29 of which are connected to the switches 24, 19. In the position shown the switch 19 of the electromagnet 20 is open and the armature 21 is locked by the armature 15 and holds the switch 24 of the electromagnet 16 closed. The circuit of this electromagnet is, however, open as the arm 31 of the switch 28 is on the contact 29. When the change-over switch 28 is actuated by pressing the button 32 the arm 31 engages the contact 27 and closes the circuit of the electromagnet 16 which attracts its armature 15 and releases the member 10 so that the counting mechanism 6 is engaged with the driving system 1, 2. At the same time the pin 18 closes the switch 19 and the armature 15 releases the armature 21, so that the switch 24 is opened and the coil 16 de-energized. The armature 15 is locked in its attracted position by a shoulder on the armature 21. If the button 32 is again depressed the arm 31 engages the contact 29, the electromagnet 20 is energized and releases the armature 15, and the switch 24 closes the circuit of the electromagnet 16. A spring 34 rotates the armature 15 which uncouples the members 10, 11 and opens the switch 19, deenergizing the electromagnet 20. Several tappings may be provided on the voltage coil 3 to allow the use of different voltages. Alternatively a separate coil may be wound on the voltage core for operating the electromagnets 16, 20.