| 摘要 |
<p>1,260,565. Step-by-step jacks. E. E. DICKEY. 12 Aug., 1969 [30 Nov., 1968], No. 40253/69. Heading B8J. [Also in Division E1] An extendable safety rail support column has bearing plates 12 and 13 each covered with a rubber pad and which are pushed apart to engage a floor and ceiling of a multi-storey building during construction by the operation of a rack and pinion jack, the rack 21 being formed on a T-section member which telescopes within a tubular member 10 on which plates 23 carrying the pinions are welded. Wooden safety rails are attached to brackets 16 by nailing through holes 17, a toe-board is attached behind plate 18, and a tarpaulin is attached to loops 20. Coarse adjustment of the length of tubular member 10 may be provided by forming it as two telescopic parts having mating holes through which a pin is passed. The rack and pinion jack may be replaced by a screw jack or a toggle clamp mechanism.</p> |
