GB583977A - Improvements in or relating to apparatus for operating valves electromagnetically, particularly applicable to valves of internal combustion engines - Google Patents

Abstract

583,977. Electrically-actuated valves. LUCKHAM, P. M., and MEDGETT, J. E. Sept. 4, 1944, No. 16878. [Class 135] [Also in Group XXVII] Valves, particularly those of internal-combustion engines, are operated by an electromagnet, having a resistance in its circuit which includes a poweroperated distributer arranged so that while the valve is being opened current is supplied directly to the electromagnet, after which reduced current is supplied through the resistance to hold the valve open until the current is cut off by the distributer. In one form, Fig. 1, a casing screwed into a cylinder at 18 consists of an upper part 12 of high duty alloy and parts 13, 14. of ferrous metal, the part 14 having a fuel supply connection 17. An inserted valve seat body 19 coacts with a valve guide 20 to define a conical chamber 21 and fuel admitted to connection- 17 passes through ducts 25, 22 to chamber 21 and thence through an annular passage surrounding valve stem 31 to an outlet 34 controlled by the valve portion 32. The reduced upper part of the valve spindle carries a collar 37, forming a seating for a closing- spring 38. The valve spindle armature 42 coacts with the core 44 of an electromagnet 45. In Fig. 2, the valve is shown fitted to one cylinder of a spark-ignited internal-combustion engine. The electromagnet is in circuit with the battery 62 and terminals 63, 64 of a distributer 65. The positive battery pole is also connected through a resistance 67 to distributer terminal 66. Other terminals 68-70 are connected to the electromagnets of other cylinders. A control ring 71 fitted concentrically in the casing is rotatable from a lever 72 and is provided with insulated headed pins 74, a spring- urged arm 77 is pivoted on a fork secured to each of the terminals 63, 68, 69, 70, and each arm carries a contact brush 80 engaging the face 81 of an insulating disc 82 mounted on an engine-driven distributer spindle. By rotational adjustment of the control ring the pins cause the brush-carrying arms to be moved between the continuous line and dotted line positions as shown in Fig. 2. The disc carries spaced slip rings connected through brushes to the terminals 64, 66 respectively and further connected to shape contact strips 89, 90 on the face of the disc. When the disc is rotated. and the arms are in their outward position, the broad parts of the contacts 89, 90 sweep in succession past the brushes 80, and impart a long current impulse to the corresponding fuel valve electromagnets thereby maintaining the fuel valve open for a time corresponding to full load running conditions. During the first part of this impulse while the valve is being opened, the electromagnet is directly in circuit through the contact 89 and terminal 64, thus giving a current in the corresponding electromagnet sufficient to open the valve. For the second part of the impulse the brush engages contact 90 which through its connection with terminal 66, results in the inclusion of resistance 67, to the electromagnet circuit thus reducing the current to that required to maintain the valve open. Inward adjustment of the brushes by the lever 72 progressively shortens the,duration of valve opening and reduces the power output. The invention is also applicable to the operation of exhaust or other valves or to valves controlling the delivery of plastics. Specification 385,993 is referred to.