Patent GB-1516020-A (GB)
Title: Cooking ovens
IPC: F24C3/12
Filed: 1976-12-22
Abstract: 1516020 Ovens; burner control RINNAI KK 22 Dec 1976 [22 Dec 1975] 53691/76 Headings F4W and F4T A cooking oven comprises a cooking chamber 2, a door 3 with a stay 4, a fan 16, a main burner 26 and a pilot burner 27, an exhaust flue 21 and a control panel 7. The panel 7 includes a pivotable handle 9 for control apparatus located in chamber 6 above the cooking chamber 2 and formed by a gas control unit A and an electric control unit B. The gas control unit A includes a gas supply a, a fibre 31, a first valve 32, a gas pressure governor 33, a second electromagnetically operated valve 34, a third valve 35 and a fourth electromagnetically operated valve 36. Filter 31, valve 32 and governor 33 are combined together (Fig. 6, not shown), and valves 34, 35 together with the electromagnet 38 of valve 34 (Fig. 8, not shown) are axially disposed in a valve housing 57 which is connected directly to the gas governor 33; these parts being attached as a unit to a base 58. The gas is supplied to the pilot burner 27 by a branch pipe (65, Fig. 8) disposed between valves 34 and 35, with valve 34 actuated by a thermocouple 27<SP>1</SP> serving as a pilot burner safety valve. The electric control unit B connected to a power source e, comprises a switch 39 connected to a changeover switch 43 selectively connected to either a high voltage generator 41 for producing a spark discharge from an electrode 40 for the pilot burner 27, or a timer 42. An electric motor 15 for the fan 16 and a temperature control device 50 are connected to the timer 42. The fourth valve 36 is connected to the device 50 via a rectifier 53. The handle 9 together with a second handle 59 arranged to be moved with handle 9 are pivotally supported on a shaft (73, Fig. 4) in housing 58. The handles 9, 59 are interlinked with the gas control unit A and the electric control unit B via a mechanical linkage system (Fig. 11, not shown) which includes switch operation bars 74-76 (see Fig. 4). The units A and B are also associated with a mechanism linked with the door 3 for preventing ignition operation of the pilot burner 27 when the door is closed. The mechanism includes an arm 100 pivotably mounted in the housing 58 and having a slot 101 in engagement with a rotatable pin 105 of a member 104 which moves with the stay 4 of the door 3. When the door is closed, arm 100 moves, causing the mechanical linkage system to prevent operation of the handle 9. In operation of the oven, with door 3 open, handle 9 may be moved, along with a linked lever arm (90, Fig. 11) and with handle 59 to open valve 34, to open valve 32 via an arm (88, Fig. 4), and to connect the high voltage generator 41 to the power source. Further turning of the handle 9, causes switch 39 to close via switch operation bar 74 to energize the high voltage generator 41 and the electron 40, and thereby to ignite the pilot burner 27. Handle 9 then returns to its original position under the action of a spring (87, Fig. 11). This causes valve 35 to open, and the current to the generator 41 to be stopped. After food is inserted in the oven, the door 3 is closed, and the mechanism shown in Fig. 13 operates to change over switch 43 to connect the timer 42 to the power source. If a timer switch 116  is closed, fan 16 is operated and at the same time the rectifier 53 is energized through the temperature control device 50 and thereby the valve 36 is opened and the gas supply to the main burner 26 is effected.