| 摘要 |
PURPOSE:To execute rapid shifting between outbound and inbound movement, by providing a guide rail part, a slide member mounted to the guide rail part, a shaft mounted to the slide member, a ratchet device, a sprocket for movement, a stopper for setting a stroke, and a projected part mounted to a hook. CONSTITUTION:When a chain 4 is rotated in the direction of an arrow mark in Fig, in case a tooth 20 of a sprocket 23 for movement is geared with an upper side part 11 of the chain 4, a slide member 5 is moved rightward through the sprocket 23, a shaft 9, and a ratchet device 19. A member 5 approaches a right stopper 24', a projected part 27 of a left hook 18 is collided with the right stopper 24', and the corrosion causes disengagement of the left hook 18 from a tooth 15 of a ratchet 16. In which case, a tooth 20 of the sprocket 23 is disengaged from the upper side 11, and a tooth 21 is geared with a lower side part 12 of the chain 4. When, through rotation of the ratchet 11 by, for example, a 1/6 turn, the right hook 18' is locked to a tooth 13 of the ratchet 16, the tooth 21 of the sprocket 23 is geared with the lower side part 12 and the slide member 5 is moved leftward. |
