| 摘要 |
1. Openable pulley or muffle of the type comprising two support flanges (3, 4) or two support brackets (10, 14) with two flanges (3, 4) one of which (3) supports both the sprindle (6) of at least one groove pulley (1) over which there passes a cable (2) and, directly or by means of another component, a pivot axis (9), supporting an openable portion (4) such that the pivoting of this portion (4) about the said axis (9) enables the introduction of the cable (2) or its release from between the two flanges (3, 4), whereas a means for suspending the pulley or the load, such as a hook (5), whose axis passes substantially through the median plane of the groove pulley (1), is connected to one of the flanges (4) indirectly via a component such as a stud crossbar (15), this crossbar (15) being located, with respect to the axis (6) of the groove pulley (1), on the same side as the axis of opening (9) of the pulley or muffle, the hook (5) being connected to the openable portion (4) and not to the flange (3) supporting the groove pulley (1) such that the traction effort exerted by the load on the groove pulley (1) via the cable (2) creates torques whose effect is to close the openable portion (4) of the pulley/muffle if it is open, characterised in that the openable portion connected to the hook (5), and constituted by the flange (4) which does not support the groove pulley (1), has its pivoting axis (9) orientated perpendicularly to the axis (6) of the groove pulley (1) and offset with respect of the median plane of the groove pulley (1) such that the traction effort exerted by a load not only causes the closure of the pulley/muffle by closing up its two flanges (3, 4) but also maintains this pulley in the closed position during the entire period in which the effort due to the load is applied, means (21, 31, 43, 54, 54a) being provided so as to keep the two flanges (3, 4) spaced from one another if no effort due to a load is being applied, without opposing the closure of the pulley/muffle under the action of a load. |
