Patent GB-191327676-A (GB)
Title: Improvements in Draught Regulators for Heating Apparatus for Supplying Hot Water.
Inventor: WIESNER FERDINAND
Filed: 1913-12-01
Granted: 1915-07-15
Abstract: 27,676. Wiesner, F., and Wiesner, J. Dec. 1. Air supply and draught, regulating. - Dampers for furnaces of water - heaters are opened or closed in accordance with variations in the water temperature by a thermometer which controls electric circuits operating a mechanical relay. The air supply and flue dampers are operated by a chain 26 which passes round a chain-wheel 25. As shown, the damperoperating means, which is normally locked, comprises a weight 8 hanging from a rope 6 wound round and secured to a pulley 4, the shaft of which carries a toothed wheel 14 engaging a toothed wheel 15 on a shaft 16 carrying an arm 19. The arm 19 is linked to an arm 21 on the shaft 23 of the chain - wheel 25, and is shorter than the arm 21, so that its rotation produces an oscillating motion of the chain - wheel 25. The amount of closing of the dampers upon the operation of the apparatus may be varied by altering the effective length of the arm 19 by adjusting the pivot for the link 20 in a slot 24. The damper - operating means is normally locked by a bell-crank lever 27 pivoted on a standard 28, and having a detent 29 engaging one of two teeth 18 formed on a ratchet member 17 carried by the shaft 16. A tilting lever 30 pivoted at 31 to the standard 28 has a short slotted arm 32 engaging a pin 33 on the locking - lever 27, and the longer arm has a forked end 35 resting on the top of a plate 36<1> forming part of a rocking armature 36 for an electro-magnet 37. The shaft 16 also carries a circuit controller comprising a disk 43 of insulating-material and an electrically-conducting disk 42. The disk 43 has a contact button 52 with which spring contacts 46, 47 normally engage on opposite sides of the disk, and the disk 42 has an insulated contact 49 connected by a wire 50 with a contact 51 on the disk 43. Spring contacts 44, 45 engage the disk 42. The contacts 49, 51 are so placed that, when the shaft 16 has made a half-revolution from the position shown, they are engaged by the spring contacts 46, 45. The thermometer 38 provided in connexion with the boiler has platinum wires projecting into its stem at points corresponding with various temperatures, to any of which electrical connexion may be made by means of a plug in a slotted plate 39, and has also an electrical connexion with the mercury in the bulb. A second electro-magnet 53, with an armature 61, and batteries 54, 55 are provided, and electrical connexions between the batteries, magnets, spring contacts, and thermometers are made as shown in Fig. 4. When the water temperature is normal, a current from the battery 54 traverses the circuit made by the wires 56, 58, contacts 44, 45, wire 60, magnet 53, and wire 59, and attracts the armature 61. When the temperature rises so as to make electrical connexion through the thermometer, a current from the battery 55 traverses the circuit made by the wire 56, thermometer 38, wire 62, contacts 46, 47, wire 63, magnet 37, and wire 64, and the armature 36 is attracted to the magnet 37. The tilting lever 30 is then released and, falling under its own weight, operates the locking-lever 27 and releases the disk 17. The weight 8 then operates through the mechanism to turn the chainwheel 25 and so close the dampers, and also rotates the ratchet member 17. In its rotation, the upper tooth 18 of the ratchet member 17 temporarily engages a projection 34 on the locking-lever 27 so as to restore the levers 30, 27 to the position shown, the lever 27 again locking the member 17 after it has made a half-revolution. The disks 42, 43 also rotate, breaking the second of the above circuits, and allowing a spring to restore the armature 36 to its normal position and again support the lever 30. When the apparatus comes to rest, the first of the above-mentioned circuits is broken and a current from the battery 54 through the circuit made by the wire 56, thermometer 38, wire 62, contact 46, wire 50, contact 45, wire 60, magnet 53, and wire 59 energizes the magnet 53 so that it still attracts the armature 61. When, owing to a fall of temperature, this circuit is broken at the thermometer, the armature 61 drops and completes a circuit from the battery 55 through the wire 64, magnet 37, wire 67, armature 61, and wire 65, which energizes the magnet 37 causing it to attract the armature 36 and again release the damper-operating mechanism. This mechanism acts as before except that the chain-wheel 25 rotates in the opposite direction and so opens the damper, the whole apparatus being restored to the normal state shown after the half-revolution of the ratchet member 17. Winding-gear for raising the weight 8 when it has reached the bottom of its travel is provided. This comprises a pulley 5 on the shaft of the pulley 4 on to which a rope 9 winds, and a pulley 10 from which it unwinds as the weight descends. The weight is raised by rewinding the rope 9 on to the pulley 10. A spring may replace the weight to operate the dampers.