Patent GB-374167-A (GB)
Title: Improvements in the starting, stopping, and controlling gear of heavy oil engines
IPC: F01L13/00
Filed: 1931-03-11
Abstract: 374,167. Starting ; stopping ; fuel pumps. TANGYES, Ltd., Cornwall Works, JACKSON, P., Roseville, Turville Road, and PICKERING, W. V., 22, Stafford Road, all in Birmingham. March 11, 1931, No. 7521. [Class 7 (v).] Starting, stopping, and controlling gear for a heavy oil engine comprises a single control lever movable manually into three positions, in which (1) a governor is disassociated from the regulation of the fuel supply, the fuel supply to an engine cylinder or cylinders is cut off, starting air is admitted and compression is released, so that the engine is started ; (2) the starting air is cut off, compression is restored, fuel is admitted to all cylinders, and the governor is allowed to control the fuel supply, so that the engine runs normally under the control of the governor, or at a speed dependent on the position of the control lever ; and (3) the governor is out of action, the fuel supply is cut off and the engine stops. As shown in Fig. 1, exhaustvalve levers 15 and fuel-pump plungers 34 are actuated by cams-on a shaft'6 movable axially by a lever 5 engaged by a cam 3 on the spindle 2 of the manual control lever 1. The fuel pumps are also controlled by the governor 11, the spindle 12 of which engages an arm 13 on a shaft 8 connected by an arm 21 to a pump regulating bar 18. A slot 30 in the bar 18 engages a pin 31 on a sleeve 32 controlling a fuel byepass port 33 in the pump plunger 32. The slot 30 has oppositely inclined portions so that the movement of the bar first raises and then lowers the sleeve 32 ; the fuel supply is thus cut off by the action of the governor in case of undue load, e.g. if a piston seizes. In the starting position of the lever 1 and cam shaft 6, cams 14 lift the levers 15 on the compression stroke to release compression ; cams 16 actuate starting-air valves 17 which admit compressed air through valves 22 into the engine cylinders ; and a cam 4 on the spindle 2 moves a lever 7 on the governor shaft 8, moving the arm 13 out of engagement with the governor spindle 12 and moving the bar 18 into the position in which the sleeve 32 is lowered and the pump does not supply fuel. On moving the lever 1 to the running position, the cam 3 allows a spring 19 to return the cam shaft 6 into the normal position, the cams 14, 16 being out of engagement with the levers 15 and starting- air valves 17; and the cam 4 allows the governor shaft 8 to be turned by a spring 20 acting on the arm 7a, moving the pump bar 18 into a position in which the fuel pumps are active and are controlled by the engagement of the arm 13 with the governor spindle 12. The pumps can also be controlled to reduce or cut off the fuel supply by the lever 1, acting through the cam 4 and arm 7 on the governor shaft 8. In order to move the spindle 2 of the lever 1 to the stopping position if the supply of lubricating oil fails, a dashpot piston 27 acted upon by the pressure of the lubricating oil carries a plunger 29 bearing against a face 3a of the cam 3, and a spring 28 acts on the piston to move the cam if the oil pressure fails. To enable the engine to charge a starting- air receiver, a lever 23 is used to open the starting-air admission valve 22 on one cylinder. At the same time, the fuel supply to that cylinder is cut off by the pump bar 25, which is connected to the main pump bar 18 by a spring 26 so that the two bars normally move together, but is operated from the charging lever 23 by means of a rod 24. The fuel supply to the remaining cylinders is reduced during the charging of the air receiver, in order to lower the speed, by a rod 23b connecting the levers 23, 1. In a modification, the regulation of the fuel pumps is effected from the bar 18 by means of a rack 18a, Fig. 3, engaging a pinion 32a on the sleeve 32, which is formed with an inclined edge 37 terminating in a vertical edge 38 and controls the byepass passages in the pump plunger. In a further modification, the cam 3 on the spindle of the control lever 1 is provided with a pin engaging a slotted lever for moving the camshaft 6 axially, and with a second pin engaging a slotted lever on which is pivoted a lever connected at its ends to the governor spindle 12 and the pump bar 18. Inclined notches in the bar 18 are engaged by tappet levers acting on valves controlling byepass ports on the pumps. For charging the air receiver, the valve 22 on the cylinder is opened by a manually adjusted screw, which has an inclined face for engagement with a byepass valve, connected to the fuel delivery chamber of one of the pumps. The screw is not connected to the control lever 1, which has to be operated independently for reducing speed during charging.