| 摘要 |
<p>The maintenance work on tanks used in industrial processes is facilitated by the use of a hoisting machine. The hoist consists of two vertical columns (1,11) mounted on wheels (10) and joined together by telescopic cross-members (5,6,7,8). The cross-members (5,7) attached to one of the columns have toothed racks (11) which engage pinions (17) mounted on the cross-members (6,8) attached to the other column. The motion of the pinions is synchronised by a chain drive (18) so that the distance between the columns can be varied to suit the load by turning the handle (19). The load is supported on the arms (29) of a hoist.</p> |
