Patent GB-1131049-A (GB)
Title: Protective apparatus for piston engines
IPC: F02D27/00
Filed: 1965-12-10
Abstract: 1,131,049. Reversing. SOCIETE D'ETUDES DE MACHINES THERMIQUES. Dec. 10, 1965 [Dec. 10, 1964], No. 52629/65. Heading F1K. The invention relates to apparatus for protecting piston engines especially Diesel Marine engines of the type having equipment for reversing the direction of rotation of the engine. The apparatus comprises a pneumatic circuit, a start up safety system controlled by the axial position of a cam shaft a detector of the direction of rotation of the engine and a control unit for a fuel pump connected to the detector. The functioning of the apparatus will now be explained when, assuming that the push button 135 of the slide valve 134 disposed in the channel 153 is held down the reversing equipment is brought into the position for backward run. The lever 106 is brought to the stop position indicated at 114 on the guide slide 107 which effects a thrust of the actuator 108 on the push button 111 of the arresting valve 14. The slide 122 of this valve is then displaced downwardly in such a way as to obturate the blow-through orifice 120. Simultaneously the valve body 124 moves away from its seat 125 allowing communication between the conduit 147 and the conduit 150 and compressed air is admitted through the orifice 97 into the chamber 84 of the arresting obturator of the control unit 9 and from there into the first compartment 79 of the main chamber of the control unit 9 . The piston 81 thrusts back through the intermediary of the arm 103 the rod 105 of the fuel pump 8 and fuel injection ceases lever 106 is then moved to the rear position indicated at 113b on the guide slide 107 with the action of the actuator 108 or the push button 111 of the arresting valve 14 still maintained and the actuator 109 is moved by the lever 106 to press on the push button 110b of the rearward run valve 13b. The obturating slide of this valve closes the blow through orifice and puts into communication the channels 146 and 149b. Compressed air is then admitted into the cylinder 46b of the reversing equipment 4 through the orifice 47b and forces oil in the cylinder into the compartment 51b of the cylinder 51 of the equipment 4. The piston 54 then by means of the swivel levers 55 drives the distribution shafts 20 into their "backward run" position. Simultaneously the slide valve of the selector 5 of change of run is driven towards the "backward run" position by the piston 54. The lever 106 is now brought back to the stop position indicated at 114 which effects closing of the valve 13b and opening of the corresponding blow through permitting compressed air in the rear cylinder 46b to escape to atmosphere. The equipment 4 for reversing the run is now engaged in the backward run position. The lever is brought back to the normal position 116 and is then pushed towards the start up position 115 which operates the actuator 108 to act on the push button 112 of the start up valve 15 and the detent 128. Compressed air is admitted respectively through channels 152, 153b and 151 to the orifice 34 of the control of the main start up valve, to the orifice 71b of the detector of the direction of rotation passing through the selector 5 of change of run and to the orifice 88 of the chamber 82 of the slide valve of the control unit 9 without passing through the selector of change of run. Compressed air reaches the cylinder or cylinders of the engine. The compressed air in the conduit 153b reaches the orifice 71b and effects a thrust on the piston 64b which presses by means of rod 65b and detent 67b on the hub 6. If the engine rotates in the normal direction i.e. in the direction given by the reversing equipment rotation of the hub causes the detent to pivot in the direction of rotation indicated by the arrow permitting descent of the piston 64b. The fuel injection control is displaced . If the engine rotates in the abnormal direction i e. in the reverse direction to that given by the position of the reversing equipment the piston 64b cannot descend and the lateral outlet 76b is not fed with air. With the engine turning in the abnormal direction the air reaches the cylinders during the compression stroke. The unit 2 acts as a braking unit for the engine modified forms of the detector of direction of rotation are described.