Patent GB-763975-A (GB)
Title: An improved liquid fuel injection nozzle
IPC: F02M61/08
Filed: 1953-10-21
Abstract: 763,975. Fuel injectors; lubricating. PARKER APPLIANCE CO. Oct. 21, 1953 [Jan. 27, 1953], No. 29020/53. Classes 7 (2) and 7 (3). [Also in Group XI] A fuel injection nozzle for contaminated liquid fuels having relatively movable parts includes means for introducing uncontaminated liquid fuel into an intermediate point in the fit or in each of the fits between the relatively movable parts, a flow passage or passages for contaminated liquid fuel in communication with the fit or fits, and the arrangement being such that during operation of the nozzle the pressure of the uncontaminated liquid fuel is greater than the pressure of the contaminated liquid fuel at the or each point of communication between the flow passage or passages and the sliding fit or fits. The contaminated fuel is introduced into the nozzle 1, Fig. 1 through an axial passage 6 and forces back a valve member 17 against the action of a spring 38 so that the fuel may pass through ten grooves 18, in the outer periphery of a liner 10, and through tangential slots 25 into a swirl chamber 26 to discharge from the latter through an annular orifice 14. An exit poppet valve 30 is interconnected with the valve 17 by a rod 33. Contaminated fuel uncontrolled by the valve 17 may pass through radial passages 20, Fig. 2, and grooves 19 intermediate pairs of grooves 18, annular chamber 28, and helical grooves 29 in a plug 27 into the swirl chamber 26. A further part of the fuel passes through an inlet passage 7 communicating with the passage 6 and thence through an annular filter 11 of asbestos fibre held between filter cloths 12, 13 into an annular cavity 9. The filtered fuel passes from the cavity 9 through a constricted passage 42, a groove 40 in the liner 10, constricted passage 43, and a groove 41. From the groove 40 the filtered fuel passes through a passage 47 and an annular groove 46 in the inner surface of the liner 10, and prevents entry of unfiltered fuel into the sliding fit between the liner 10 and a tubular extension of the valve 17. Filtered fluid also flows from the groove 41 through a passage 51 into a helical groove 50 on said tubular extension and flushes out and lubricates the sliding fit. The tubular extension has also an annular groove 48 which may receive filtered fuel from the sliding fit and deliver it through an orifice 49 to the interior of the liner 10 from which it may pass through the tubular valve stem 32 and orifices 35 at the exterior side of the poppet valve 30. Filtered fuel also passes from the groove 41 through a passage 52 and an annular groove 53 around the valve stem 32 to enter the sliding fit between the latter and the plug 27, thus preventing entry into said sliding fit of unfiltered fuel from the swirl chamber 26. The valve members 17, 30 are interconnected by a rod 33 secured to the member 17 by an adjusting screw 36 whereby the compression of the spring 38 may be varied. On commencing the fuel flow the valve 31 opens when the fuel pressure on the valve 17 barely overcomes the spring 38, and fuel passes through channels 19, annular chamber 28, spiral passages 29, and swirl chamber 26 to discharge through the orifice 14. As the fuel pressure builds up the valve 17 moves further to allow fuel into the channels 18 at a rate depending on the contour of the valve 17 and on the compression of the spring 38. The filtered fuel escaping through the orifices 35 may be directed into the spray cone of unfiltered fuel discharging through the orifice 14 by means of a tubular member 70, Fig. 7, surrounding the orifices 35 and having a flange portion 75 co-operating with a bevelled flange 31 of the valve member 30 to define an annular passage 76 which may, alternatively, be directed radially. The nozzle 1 may be mounted in a holder 56, Fig. 5, at the end of a fuel supply conduit 58 and containing additional filtering means. A large mesh screen 60 filters the fuel entering a central tube 62 leading to the passages 6 controlled by the valve 17, and a small part of the fuel passes through holes 64 in the tube 62 and into annular asbestos filter discs 65 and passes from the outer edges of the latter into the peripheral space defined by the filter discs 65, stainless steel spacing rings 66, and a surrounding wall 63. From this peripheral space the fuel flows through a screen 67 into an annular passage 68 communicating with the passage 7.