Patent GB-768015-A (GB)
Title: Air register for fuel burner
IPC: F23C7/00
Filed: 1955-03-08
Abstract: 768,015. Supplying air to burners. PEABODY. Ltd. March 8. 1955. No. 6759/55. Class 75(1) A burner comprises reversible drive means, e.g. a reversible electric motor 45, for operating the adjustable doors 21 of an air register 20, a plurality of stop means, e.g. cam - operated switches 71-75 in the supply circuit to the motor, operable to stop the motor at different door positions and means, e.g. manual switches 84, 89, 104, for rendering the stop means operative so as to position the doors in accordance with selected combustion requirements. The doors pivot about rods 22 and have pins 23 fastened to a ring gear 24 engaged by a pinion 25 on a shaft 26 detachably coupled to a drive shaft 31 driven through reduction gear by the motor 45. The drive shaft 31 carries a set of cams 65-70 for actuating the switches 71-75 controlling the motor and a switch 76 controlling an igniter 108. The burner control circuit, Fig. 5, comprises the manual switch 84 which connects either a contact 85 or two contacts 86, 87 to the electric supply line 83 to provide manual or automatic control of the motor 45. The contact 85 is connected to the manual switch 89 which is a. two way switch adapted either to close a contact 90 to operate the motor in a direction to close the doors or a contact 91 to operate the motor in a direction to open the doors. The motor is automatically stopped when the doors reach the fully closed or open positions by the cam-operated switches 71, 72. The contact 87 of the manual switch 84 energizes the motor to open the doors through the cam-operated switch 73 which opens when the doors have moved to a, slightly open position suitable for the operation of a pilot flame. At the same time the contact 86 of the manual switch 84 energizes the igniter 108 and if ignition occurs a flame detector 117 is actuated by the pilot flame to energize a relay 116 to close two ganged switches 103, 110. Switch 103 connects contact 86 of the manual switch 84 to the manual switch 104, and switch 110 connects the supply line 83 to a selector switch 111 ganged to the manual switch 104. The manual switch 104 is a two way switch and energizes the motor in both its positions to open the doors but the cam operated switches 74, 75 de-energize the motor in different positions of the doors corresponding to the burner being supplied with oil fuel or gas. The selector switch 111 is also a two-way switch and energizes relays 114, 115 to open either a valve supplying oil fuel or a valve supplying gas to the burner. The cam-operated switch 76 de-energizes the igniter before the doors reach their operating positions. The manual switch 84 and the three two-way switches 89, 104, 111 are mounted on a panel remote from the burner. The degree of opening of the doors is indicated on the panel by a coltmeter 121 connected to an adjustable rheostat 78, the contact arm 77 of which is connected to the drive shaft 31. The reduction gear, Fig. 2, between the drive shaft 31 and the motor 45 includes a worm gear 35 on the drive shaft meshing with a worm 36 journalled on a vertical shaft 37 having a spur gear 39 meshing with a pinion 40 on a second vertical shaft 41 carrying a worm gear 42 meshing with a worm 43 on the shaft 44 of the motor. The worm 36 is attached to a sleeve 50 journalled in a bearing in the gear housing 32 and detachably coupled to the first vertical shaft 37 by a hand wheel 56 which is keyed to the'sleeve 50 and is spring-urged into an upper position in which a pin 64 on a disc 63 fixed on the upper end of the first vertical shaft 37 engages a recess 62 in the hand wheel. The hand wheel is depressed to disconnect the sleeve from the shaft 37 and the doors can then be adjusted by rotating the hand wheel manually. The burner may be adapted for pulverized' fuel. U.S.A. Specification 2,446,069 is referred to.