GB412960A - Improvements in or relating to fluid-pressure relays for controlling the transmission gear of marine engines - Google Patents

Abstract

412,960. Controlling reversing - gearing. CLAYTON DEWANDRE CO., Ltd., and EDGE, S. H., Titanic Works, Lincoln. Jan. 2, 1933, Nos. 79 and 29231. [Class 80 (ii).] Comprises a vacuum or compressed-air operated relay for moving transmission gear to the ahead, neutral, or astern position. A rotary valve controls the fluid; the engine throttle is adjusted with the valve ; the cylinder pressure is released when the gear is in the ahead position to avoid wear. The manuallyoperated rotary distributing valve 1 is provided with ports 4, 5 and groove 6, 7. The port 9 in the valve casing communicates with ports 26 in the centre of the cylinder, and ports 11, 12 communicate with the atmosphere. The control lever operates the valve 1 through a grooved pulley 17, the shaft 13 of which carries a double cam 14 which through a rod 15 operates the engine throttle. The lever may be locked in the ahead, neutral, or astern position. The interior of the valve is subject to suction or compressed air. When the valve 1 is rotated clockwise, a vacuum is induced in the right-hand end of the cylinder, and the left hand is put to atmosphere by the grooves 6, 18, and ports 11, 20. The piston 27 moves to the right, and the slide valve 33 to the left. When the valve 1 is returned to the neutral position, the right hand end of the cylinder is put to exhaust, and the ports 26 to vacuum which causes the piston to return to the central position and close the port 36 by means of the valve 33. An auxiliary valve, Fig. 4, is provided to close the suction and open the cylinder to atmosphere to destroy the pressure on the piston and gear lever to ensure slackness in the clutch withdrawal mechanism to obviate wear. The passage 38 communicates with the cylinder, and the connection to the atmosphere and suction is controlled by valves 39, 40 acting in conjunction. The sleeve valve 39 is spring-pressed and engages a seat 41 to cut-off the vacuum. The plunger 40 is spring-pressed and engages the valve 39 to cut off communication with the atmosphere through ports 44. The rod 45 is connected to a hand-controlled device adjacent the control handle of valve 1. When the operator releases the handle of valve 1 it remains in its adjusted position but the rod 45 is freed and the valve 40 is moved to open the passage 38 to atmosphere. In working the apparatus by compressed air, the pipe 25 connects the port 9 and port 36, and the port 8 is connected to the ports 26. The outside connections to the hand control or to the transmission gear are modified to cause the piston to move opposite to the movement it has under vacuum.