| 摘要 |
<p>PURPOSE:To stably provide an adequately strong hoisting power without the weight increased very much and the whole size increased in a hoisting type pulley in which the running support of a rope and the driving hoist can be selectively performed. CONSTITUTION:The shape of a groove 24 for a rope of a wheel 11 is made like a notch, and at the same time the width of the rope groove 24 is expanded and reduced in accordance with a load hung on the rope R so as to change the supporting condition of the rope in accordance with the expansion and reduction thereof. That is, at the time of hoisting when a small load is applied to the rope R, a press-down power against the rope groove 24 is doubled according to the principle of a notch with the rope R being held between the side walls of the rope groove 24 on the condition that the rope groove 24 floats off from the bottom of the rope groove 24, and an adequate hoisting power is maintained without so much press-down force required. At the time of the running support of the rope R on which such a large load as a ton manitude is hung, the rope R is pressed down in the bottom of the rope groove 24 for support, thereby preventing the rope R from being damaged.</p> |
