SPRAG JACK WINCH FOR REGULATING OPENING AND CLOSING SPEED OF A WATER GATE WITH A SPEED CHANGE MECHANISM

摘要

PURPOSE: A sprag jack winch is provided to prevent the water gate from being dropped suddenly from the tare of the water gate by a screw brake in stopping the water gate or at the neutral range of the gear while opening or closing the water gate, and to transmit power efficiently by mounting a worm and a worm wheel in the main decelerator. CONSTITUTION: A sprag jack winch is composed of a worm unit(50), a spiral bevel gear(40) combined with the worm unit to transmit power, a transmission unit(30) combined with the spiral bevel gear at the same axis to change the speed of the gear according to the power transmission of the spiral bevel gear, and a screw brake unit(20) combined with the transmission unit to prevent the water gate from being dropped suddenly. The screw brake unit has a first gear rotated fast by driving a first pinion, a couple of pressure plates mounted to the first gear and pressed by driving the first gear, a ratchet wheel integrally pressed between the pressure plates and rotated unidirectionally, a pawl combined with the upper part of the ratchet wheel to rotate the ratchet wheel unidirectionally, a screw brake shaft inserted to the pressure plates and rotated with the pressure plates, and the second gear combined with a second pinion and rotated at low speed.