| 摘要 |
<p>1306856 Hoists D L PRUITT 1 June 1970 [2 June 1969] 26343/70 Heading B8B An electric hoist includes a lifting chain rotor 14 driven through spur reduction gearing by a reversible series electric motor 18 having an infinitely variable speed controller 70, the ratios of the reduction gearing being sufficiently large to render the gearing irreversible by the static torque applied to the gearing by the maximum rated load for the hoist. Lifting and lowering of the hoist load is therefore positively controlled by the motor. The gear casing 20 attachable to the hoist body 10 is independently removable to facilitate gear-wheel changes, the gears all being primarily supported from the body 10.</p> |
