Patent GB-789404-A (GB)
Title: Improvements in fluid fuel control devices
Inventor: JACKSON WILBUR FRED
IPC: F23N5/10
Filed: 1955-10-18
Abstract: 789,404. Valves. ROBERTSHAW-FULTON CONTROLS CO. Oct. 18, 1955 [March 23, 1955], No. 29737/55. Class 135. In a burner control device comprising a casing having a fuel inlet 12, Fig. 3, an outlet 14, and an interconnecting passage 18, all having longitudinal axes defining a plane, a shut-off valve 24, an electromagnetic safety shut-off valve 131, and a thermally responsive valve 62, Fig. 2, the valves control the flow of fuel through the passage 18 and are located in the latter with their longitudinal axes arranged, respectively, on the plane, parallel to the shut-off valve and on the plane, and perpendicular to the plane. In the passage 18, Fig. 3, is a conical bore 22 housing the rotary shut-off valve 24 having a bore 26 with a lateral opening 27 and an opposed recess 28, so that in the one position of the valve 24 fuel flows through both the bore 26 to the main burner outlet 14, and the recess 28 to the pilot burner outlet 16 whilst in another position of the valve fuel is supplied to the outlet 16 only; in a third position fuel is prevented from flowing to either burner. Within the valve bore 26 is a flexible split-sleeve closure 52 which is connected with the shut-off valve operating knob 50 but which may be rotated relative to the valve 24 to vary the effective size of the opening 27; the closure 52 is attached to its shaft 32 by flanges and a resilient tongue. Downstream of the shut-off valve 24 is the thermally responsive valve 62, Fig. 2, having a simple lift closure with a seat 64 and a stem 70 that co-operates with a known snap-acting mechanism 74 having its operating button abutting a lever 80, which latter is also centrally engaged by the non-expansible rod 86 of a rod and tube thermal element 82. The lower end of the lever 80 is pivoted upon one end of an operating shaft 90 that is in a sealing sleeve 92 where it crosses the outlet 14, the other end of the shaft engaging an adjustable threaded member 94 to which is fixed a stop 98 carrying an operating knob 106, rotation of which adjusts the temperature whereat the thermal element will actuate the lift closure. A spring member 110 is provided to both frictionally restrict movement of the knob 106 and to enable a cover 108 to be attached to the apparatus housing 10. Adjacent the inlet 12, Fig. 3, is the safety valve 131 for shutting-off the fuel supply to both burners should the pilot flame fail, which valve comprises a simple lift closure on a stem 136 connected to a thermocouple 140 located near the pilot burner and in circuit with an electromagnet 138, the current to which is only sufficient to maintain the armature in engagement with the pole faces; the closure is manually opened by a rod 156 secured to a push-button 144 in a cover-plate 148. In order to prevent the closure being opened when the valve 24 is supplying both burners the latter is interlocked with the button by means of a washer 170 fixed to the valve 24, a slide 168 and a ball 160. Another cover-plate 172 enables the shut-off valve 24 to be removed from the housing 10 without disturbing the interlocking mechanism and whereupon movement of the latter is prevented. The pilot outlet 16 is supplied with fuel from the recess 28 by way of a passage 20, and a chamber 174 in which is a filter; the rate of flow through the outlet may be controlled by a needle valve 176.