GB765808A - Improvements relating to nozzles for dispensing fluid under pressure - Google Patents

Abstract

765,808. Valves. SCULLY SIGNAL CO. July 7, 1954, No. 19901/54. Class 135. A nozzle or valve for dispensing fluids, particularly fuel oil and petrol, comprises a body 4, Fig. 1, forming a hand-grip for the nozzle and housing a main piston-valve 16, controlled by a manually-operated, axially-slidable pilot valve 18, for regulating the flow of liquid between a supply hose 12 and a delivery spout 8. The piston valve has a bleed hole 58, sealing-rings 50, 52 and guide webs 44. The pilot valve has a bore 66 communicating with a radial orifice 70, and a spring-loaded vacuum release valve 108 operated by a press-button 114, and is movable axially by a button 82 secured to its upper end. The pilot valve may be locked in its lowermost position, corresponding to the closed position of the piston valve, by a latch 88, Fig. 6, which engages a recess in the button 82 and is formed with slots engaged by pins 94, 96 and 102, the pins 94, 96 being secured to members 90, 92 adapted to be pressed inwards to release the latch, and the pin 102 to the body 4. Fluid-tight sealing-rings 62, 64 are provided between the body, main piston valve and the pilot valve 18. Encircling the pilot valve is a spring 80 bearing against a loose washer 76 which, in the closed position of the main valve, bears against a collar 74 secured to the pilot valve and upon which nests a resilient washer 78. In the closed position of the piston valve, the spaces around and above the valve are full of oil under pressure and the valve is held closed by the resultant downward thrust of the oil and the spring 80. To open the valve, the latch 88 is released, whereupon the pilot valve is moved upwards by the spring to a position in which the button 82 is accessible to the operator who can then raise the pilot valve further. As soon as the orifice 70 is sufficiently clear of the sealing- ring 64, oil begins to flow from the space above the piston valve, thus reducing the pressure in said space, since the oil flowing into the space through the bleed-hole 58 is less than that leaving through the orifice 70, so that the piston valve is moved upwards to its open position by the pressure of the oil on the underside of the valve head 38. Thus, the sealing-ring 64 overtakes the orifice 70 and cuts off the flow from above the piston valve whereupon the pressure above the piston builds up and forces the piston valve down until the orifice 70 is again uncovered. When the piston valve is open, the oil flows from the hose 12, through the port 34 and the spaces between the guide webs 44 into the discharge spout 8. The flow between the hose and the body 4 is checked by a valve loaded by a light spring. Fig. 2 shows the piston valve in its fully open position with the spring washer 76 bearing against fingers 46 formed on the piston valve. Fig. 9 shows a modification in which the pilot valve is operated by a hand-lever 124, and in which the vacuum release valve is replaced by a short bore 128 in the pilot valve extending between lateral orifices 130, 132 communicating with the spout 81 and the atmosphere respectively. In another arrangement, the pilot valve is operated through a hollow push-rod 138, Fig. 11, the upper open end of which closes on a rubber washer 142 carried by the pilot valve when the push-rod is raised, and which permits venting of the spout through the orifice 150 when the valve is in its lowermost position. Fig. 13 shows a further modification in which the pilot valve consists of two separable parts 170, 172, and in which the upper end of the part 170 is bent over to form a handle 180 that can be engaged in a recess 184 in a part 186 of the body to hold the piston valve closed, or turned through 90 degrees to permit opening of the valve. In this modification, the opposite sides of the piston valve are connected by a by-pass 200, and a notch 201 facilitates the escape of oil from above the piston valve as the latter reaches its maximum opening position. A check-valve in the form of a spring flap 206 'is provided between the hose and the body to prevent draining of the hose when the nozzle is not delivering. In another arrangement, the bleed hole 58 is replaced by a by-pass extending through the body of the nozzle and connecting the supply side of the flap valve directly to the space above the piston valve. In a further arrangement, including means for manually opening or closing the valve to its fullest extent, the pilot valve 314, Fig. 19, carries a radial arm 358 mounting a roller 360 engaging a cam groove 356 in an adapter 312 which is screwed into the body 4, and which has a sealing-ring 310 with an extension 308 forming a seating for the valve 304. Within the valve is a casing 336 containing a spring 342, the upper end of which bears against a flange on a cup member which may be engaged by a pin 344 carried by the pilot valve. The valve 4 is opened or closed by rotating the pilot valve by means of a lever 362 having a catch 364 engaging a recess in the body of the nozzle. The discharge spout may be formed with vacuum release grooves 374.