| 摘要 |
In a multi-purpose ladder of the invention there are disposed on bores (30) in the left and right halves (8, 9) of a second joint element (5) curved recesses (39), not shown here and shaped corresponding to the pivot movement of an operating lever (40), for containing bearings (31) of a release lever (32). Arms (33) of the release lever (32), which cooperates with the operating lever (40), are connected with each other by means of a bar (34) having a recess (35). Protrusions (37) are formed at bearings (31) of the release lever (32) by deep drawing of side wall portion of the arms (33). A cam (42) of a first elbow (41) of the operating lever (40) can be inserted into the bearings (31), the operating lever (40) being securely guided by the recess (35) in the bar (34). The cam (42) comprises an upper semicircular part (43) and a key bit (44), not shown here, the semicircular part (43) having an oblique surface (43a) and the key bit (44) an oblique surface (44a) at a front face (45) of the cam (42). The key bit (44) has key surfaces (47) extending across the entire length of the key bit (44). Fig. 8 |
