GB426466A - Improvements in or relating to reversing gear for internal combustion engines - Google Patents

Abstract

426,466. Starting, stopping, and reversing. SULZER FRERES SOC. ANON., Winterthur, Switzerland. Aug. 21, 1934, No. 24077. Convention date, Dec. 6, 1933. [Class 7 (v)] [See also Group XXVIII] In a reversing-gear for marine engines of the fuel-injection compression-ignition type, apparatus for acknowledging orders received through an engine-room telegraph is so associated with the reversing gear that actuation of the acknowledging apparatus to confirm an order to reverse causes the valve gear to be set for reverse operation of the engine and cuts off the fuel supply, which is automatically restored when engine rotation in the reverse direction has been established by the operation of a starting lever. In the arrangement shown, starting in either direction is effected by compressed air admitted from a supply pipe 11 through a starting valve 12 actuated from forward and reverse cams 4, 5 movable axially on the cam shaft 3. The actuation is effected through a roller 7 movable into and out of engagement with the cams by a starting lever 9 and a link 8. The telegraph 2 comprises a fixed scale plate 21 and a pointer 22 controlled from the bridge, and the order is acknowledged by moving a lever 24 so that a pointer 25 thereon lies opposite the pointer 22. The lever 24 is secured to a shaft 26 which carries a disc 27 having a cam groove 28 for effecting the axial movement of the cams 4, 5 by means of a lever 30, link 32, bell-crank 35, and fork 6. The lever 24 is also connected by a link 36 to a member 38 for controlling the fuel supply by acting upon the suction valve 18 of the fuel-injection pump 16. A tappet member 42 sliding in a guide 41 carries a roller bearing on the control member 38, and a lever 62 pivoted at 61 is interposed between the tappet member 42 and the stem 23 of the valve 18. Beneath the control member 38 is a lever 39 pivoted at 43 and movable between stops 44. The lever 39 carries a roller 40 for engagement with a cam face 37 on the member 38. A rod 47 in pin-and-slot connection with the lever 39 has a tooth 45 for engagement by dogs 48 formed by a slotted ring 49 mounted on the cam shaft 3, the rod 47 being held in frictional engagement with the cam shaft by the pressure of starting air acting through a branch pipe 53 on a piston 52 ; the pipe 53 is connected alternately to the air main 11 and to an escape port 56 by a valve 54 having a stem 55 resting on the lever 62. The parts are shown in the position corresponding to " slow speed astern." When the order to " stop " is received and the lever 24 is moved to the position S on the scale 21, the cams 4, 5 are moved by the cam 27 so that they lie on either side of the roller 7, and the control member 38 is moved so that the cam face 37 rides on to the roller 40 and the suction valve 18 of the pump is opened. On receipt of the order " slow speed ahead," the lever 24 is moved to the position L on the left side of the scale 21, bringing the starting cam 4 into the plane of the roller 7 and cutting off the fuel supply by means of the member 38, the cam face 37 on which rides on to the roller 40 and causes the member 38 to lift the tappet 42 and the pump valve 18. The engine slows down, the cam shaft 3 continuing to rotate in the direction indicated by the arrow, but at reduced speed. The lever 9 is now moved to the starting position A, bringing the roller 7 into engagement with the cam 4, so that the valve 12 is actuated for reverse operation of the engine and the engine is brought to rest and reversed. At the same time, an arm 20 on the lever 9 lifts the member 62 sufficiently to open the valve 54 and admit air to the cylinder 51, so that the rod 47 is held in frictional engagement with the ring 49. On reversal of the cam shaft, the rod 47 is moved to the left by one of the dogs 48, tripping the roller 40 from beneath the cam 37 and allowing the member 38 and the tappet 42 to drop. The engine will operate in the new direction under starting air until the lever 9 is returned to the working position B, when the member 62 is allowed to drop and the valves 18, 54 to close.