Feed control means for oil burners, especially for heating plants

865,674. Valves. MISSION MANUFACTURING CO. Dec. 3, 1957, No. 37584/57. Class 135. In a liquid feed control device, particularly for oilfed burners, the liquid passes through a passage 9 provided with main and auxiliary valves 12, 33 respectively operated by floats 13, 18 in a common casing 1 and so arranged that the auxiliary valve is operated to cut off the liquid supply in the event of failure of the main valve. The auxiliary float 18 is of annular form surrounding the main float 13 and is carried by spaced arms 19 between which is mounted a second arm 24 loaded by a spring 26. In the event of failure of the main valve 12 float 18 is raised and arms 19 engage a bridge piece 30 to rotate arm 24, thereby closing valve 33 through an arm 28 and also raising an indicator pin 34. Due to the action of spring 26 valve 33 remains closed and pin 34 raised if the liquid level falls, and to restore the apparatus to its normal operating condition the pin 34 must be depressed to overcome spring 26 and open valve 33. Flow through the outlet 3 is controlled by a valve in the form of a piston 47 formed on its periphery with an upwardly-tapering flow groove 52 registering with an inlet port 48. The axial position of the piston may be varied to regulate the width of the flow groove presented to port 48 by engaging a detent 81 on a rotary spindle 58 with the appropriate one of a number of notches 72, 73, ... disposed on the helical edge of a boss 71. In the lowermost position of piston 47 a spring-loaded ball 59 at its lower end closes the outlet 3. The float casing may be heated, either electrically or by heated fluid flowing through passages in the wall.