GB369676A - Improvements in reversing mechanism for internal combustion engines - Google Patents

Abstract

369,676. Reversing. BENTLEY, H. H. and REBBECK, F. E., of Harland & Wolff, Queen's Island, Belfast. Jan. 1, 1931, No. 30. [Class 7 (v).] In a device for reversing the direction of rotation of the reversing shaft 7 and for cutting off the driving power to the shaft, when it has completed a desired movement, until manually operable means are operated to restart the driving power in the opposite direction, the shaft is driven from an electric motor 12 through worm gearing 9, 10 and the motor is controlled by switch mechanism controlled by axial movement of the worm spindle, a stop being carried by the shaft 7 for engaging an arresting device when the shaft has completed a prede. termined angular movement in either direction. As. shown, the shaft 7 carries an eccentric 6 on which., is pivoted the fuel-valve lever 5, so that the lever may be lifted to allow the actuating cam 3 to be moved axially. The worm 10 is movable axially against a spring 15, pneumatic cushioning cylinder, or other resilient device,: which just balances the end thrust on the worm when it is driving the worm wheel 9. When the motion of the worm wheel is arrested, the axial movement of the worm against the tension of the spring 15 continues until an extension 20 of the worm shaft causes a limit switch 24 to cut off the current supply to the motor. The stop means for the worm wheel consists of a pin 25 on the wheel and a pivoted catch 28 normally resting on a stop 31 and having a pair of stop projections 26, 27, one or other of which is encountered by the pin 25. The electrical connections are indicated in Fig. 2; double-pole switches S<1>, S<2> for the motor armature A are operated by coils c<1>, c<2> connected to a main reversing switch M and to contacts 1, 2, 3 of the limit switch, which may, comprise a sliding plate L having notches a, b. On moving the switch M to position I or II, the coil c<1> or c<2> closes the switch S<1> or S<2> and starts the motor in one or other direction. When the worm wheel 9 is stopped,..the.worm spindle 11 moves the limit switch to bring one of the notches a, b over the corresponding contact 2 or 1, deenergizing the coil c<1> or c<2> and causing the switch S<1> or S<2> to cut off the current supply to the motor until the switch M is moved over to the other contact.