| 摘要 |
A base plate (1, fig 1, not shown) for a scaffolding arrangement has an upwardly facing socket (5) to receive a load bearing element of the scaffold (6). Across the lower part of the socket (5) there is an elongate cam (31, fig 4, not shown) which can rotate about its axis possibly by using an operating arm (35, fig 4, not shown) which extends radially from the cam. The cam (31) has point symmetry in cross section and has a height greater than its width (fig 5, not shown), so that it may support the scaffold element (6) in a first position (fig 5) and then lower the element (6) to a second lower position (fig 6, not shown) when the cam (31), is rotated. Rotation of the cam (31), may be assisted by, for example, a spring (40). A protective housing (17) may enclose the space through which the operating arm (35) travels. |
