A rope fastening arrangement of a hoisting device, which comprises a rope drum, a fastening device having a chamber which defines the vertical boundary dimensions, the horizontal boundary dimensions, and depth direction boundary dimensions of the fastening device, a hoisting rope and a hoisting member which by means of the hoisting rope ascends and descends supported by the fastening device and rope drum. Said rope fastening arrangement further comprises that the hoisting rope (4) is locked to the fastening device by wedging, whereby the fastening device guides the first end of the hoisting rope away so that the first end of the hoisting rope does not extend outside the vertical boundary dimensions of the chamber.

A power transmission system that is adapted to transmit forces from a motor to a component comprises an externally threaded shaft 551 that is rotatably attached to the motor, an internally threaded fastener that is movably attached to the externally threaded shaft, a first element, and a second element that is movably attached to the first element at a second joint and that is rigidly attached to the component at a third joint.

A power transmission system that is adapted to transmit forces from a motor to a component comprises an externally threaded shaft 551 that is rotatably attached to the motor, an internally threaded fastener that is movably attached to the externally threaded shaft, a first element, and a second element that is movably attached to the first element at a second joint and that is rigidly attached to the component at a third joint.

A manhole guard, methods of assembling the same, and methods of using the same, are described. The manhole guard generally includes a plurality of sections connected for movement, the sections being capable of being locked into a fixed rigid structure through the use of a first arm and second arm that act independently of each other. The manhole guard may include a safety net attached to one or more sections of the manhole guard. The manhole guard may include attachable mounting brackets designed to facilitate the attachment of a first hoist device and/or first winch and include attachable mounting members designed to facilitate the attachment of a second hoist device and/or second winch.

A manhole guard, methods of assembling the same, and methods of using the same, are described. The manhole guard generally includes a plurality of sections connected for movement, the sections being capable of being locked into a fixed rigid structure through the use of a first arm and second arm that act independently of each other. The manhole guard may include a safety net attached to one or more sections of the manhole guard. The manhole guard may include attachable mounting brackets designed to facilitate the attachment of a first hoist device and/or first winch and include attachable mounting members designed to facilitate the attachment of a second hoist device and/or second winch.

A small, portable, powered winch that may employ a power drill or socket wrench.

Units for distributing three-phase power to a plurality of chain motors are provided, as are used to raise and suspend production elements such as lighting, sound, video, and scenery. Remote switching and phase reversal of such power are also provided. In the prior art, such switching has been performed by large, heavy contactors inserted between the single power input and its distribution to plural outputs for motors, making the unit difficult to handle and ship. Provided herein are power switching and phase reversal performed by a plurality of parallel such means, reducing the current requirements for each, and thereby the size, weight, and cost of the whole. In some embodiments, the single power input is replaced by a by a cable delivering a plurality of two-phase circuits to the unit which derives the three-phase circuits necessary for chain motors therefrom.

A chain inlet/outlet, from which a load chain on a load side is hauled in or paid out, has a first guide groove having a first longitudinal groove and a first lateral groove. The chain inlet/outlet also has a second guide groove that is provided on a deeper side of a body part than the first guide groove is and has a second longitudinal groove and a second lateral groove. The first guide groove has narrowed parts that determine, when each link of the load chain is pulled in, into which of the first longitudinal groove and the first lateral groove the link is introduced, and expanded groove parts having a width larger than the groove width of the narrowed parts and provided on the outer side, farther away from the center of the chain inlet/outlet than the narrowed parts.

A chain inlet/outlet, from which a load chain on a load side is hauled in or paid out, has a first guide groove having a first longitudinal groove and a first lateral groove. The chain inlet/outlet also has a second guide groove that is provided on a deeper side of a body part than the first guide groove is and has a second longitudinal groove and a second lateral groove. The first guide groove has narrowed parts that determine, when each link of the load chain is pulled in, into which of the first longitudinal groove and the first lateral groove the link is introduced, and expanded groove parts having a width larger than the groove width of the narrowed parts and provided on the outer side, farther away from the center of the chain inlet/outlet than the narrowed parts.

A lean-to rigging apparatus is described for installation in a shaft, such as an elevator shaft, having a wall and including at least one sill opposite the wall. The rigging apparatus includes a spanning beam, a sill support structure, a wall support member, and a hoist connector. The sill support structure on a first end of the spanning beam is designed to seat against a sill in the in the shaft while the wall support member on a second end of the spanning beam abuts against the opposite shaft wall. The sill support structure is rigidly connected to the spanning beam in a hingeless configuration and can seat against a sill in a plurality of seating positions. These seating positions allow the rigging apparatus to be positioned in a plurality of angles and therefore to be installed in shafts of different dimensions. The hoist connector is configured to allow a connection to a hoist device for hoisting various materials from one level to another within the shaft.