GB778528A - Climbing device for raising and lowering platforms - Google Patents

Abstract

778,528. Friction ratchet jacks; platform hoists. BERA BERLINER RAHMENGERUST GES. Jan. 20, 1956 [Jan. 24, 1955], No. 1942/56. Class 78 (3). A friction ratchet device for raising and lowering a working platform on a scaffold comprises two clamps slidably mounted on a scaffold standard, the lower clamp carrying the working platform and a pivoted link pivoted to a hand lever which is also pivoted to the upper clamp and which is used to raise and lower the device on the standard. As shown, Fig. 1, clamps 1, 2 are slid along a scaffold standard 3 by reciprocating a hand lever 5 hinged to the clamp 1 and to a rod 7 pivoted to the clamp 2 at 8, the platform (not shown) being suspended by a bar 9 suspended from the pivot 8. The clamps are provided with arcuate surfaces 15, 16, 17, 18 abutting detachable inserts 10, 11, 12, 13 which bear against the standard 3. The clamps are held in position by set screws 21, 22, 24 in brackets 19, 20, 23 on the clamps. The device is raised by operating the lever 5 after tightening screws 22, 24 and slightly loosening screw 21. To lower the device, the lever 5 is operated after moving the rod 7 to the position shown in chain dotted lines and tightening screw 21 and loosening screws 22, 24. In a second embodiment, Fig. 3, the arcuate surfaces on the clamps are formed by bolts 31, 32, 33, 34, and the set screws are replaced by springs 26, 27 removably screwed to the clamps at 28, 29. To raise the device the handle 5 is operated as before, but to lower the jack, the springs 26, 27 are turned through 180 degrees about the screws 28, 29, the rod 7 being left in the one position.