A hoist security arrangement for avoiding dropping of the load when the chain or cable breaks includes a longer redundant auxiliary chain or cable disposed alongside the main chain or cable and which is raised and lowered synchronously with the slightly shorter main chain or cable so that the main chain or cable normally supports the entire weight of the load. If the main chain or cable breaks, the load drops slightly until the slack in the redundant auxiliary chain or cable is eliminated to hold the load solely by tensioning the auxiliary chain or cable. The extent of slack is set to insure that slight lengthening of the main chain as caused by wear does not result in loading of the auxiliary chain or cable.

A hoist system having a drum primarily self-contained within a batten, for raising and lowering lighting, sound equipment, curtains and the like, often in a performance environment. The compact system is highly scalable to a variety of spaces and applications, including school and public theaters and concert halls, as well as some homes, private business, etc. The hoist system may be adapted with safety mechanisms including an overspeed detector, which may comprise a centrifugal detection mechanism coupled to an elongate member of the system; dampening means; a compact mechanism for trimming or adjusting an operative length of elongate member; stabilizing pipe shaft bearings; elongate member diverter pulley mechanisms load balancing termination points. Additional features include various alternative combination hoist implementations and orientations, and alternative incorporated attachment mechanisms for use with the hoist system.

A hoist system having a drum primarily self-contained within a batten, for raising and lowering lighting, sound equipment, curtains and the like, often in a performance environment. The compact system is highly scalable to a variety of spaces and applications, including school and public theaters and concert halls, as well as some homes, private business, etc. The hoist system may be adapted with safety mechanisms including an overspeed detector, which may comprise a centrifugal detection mechanism coupled to an elongate member of the system; dampening means; a compact mechanism for trimming or adjusting an operative length of elongate member; stabilizing pipe shaft bearings; elongate member diverter pulley mechanisms load balancing termination points. Additional features include various alternative combination hoist implementations and orientations, and alternative incorporated attachment mechanisms for use with the hoist system.

A chain tensioning arrangement for a column pipe which is configured to house a submersible pump. The chain tensioning arrangement includes a radially extending cross beam, a spring arrangement connected to the cross beam, at least one spring member, and an arm that is movably connected to the cross beam. The arm includes an engagement member configured to optionally engage a chain connected to the pump. The arm is displaceable in the axial direction between a lower position and an upper position. The spring member is arranged to displace the arm in the direction from the lower position towards the upper position. Also described is a pump station including a column pipe, a submersible pump arranged in the column pipe and an axially extending chain connected to the pump and configured to move the pump in the column pipe.

A chain tensioning arrangement for a column pipe which is configured to house a submersible pump. The chain tensioning arrangement includes a radially extending cross beam, a spring arrangement connected to the cross beam, at least one spring member, and an arm that is movably connected to the cross beam. The arm includes an engagement member configured to optionally engage a chain connected to the pump. The arm is displaceable in the axial direction between a lower position and an upper position. The spring member is arranged to displace the arm in the direction from the lower position towards the upper position. Also described is a pump station including a column pipe, a submersible pump arranged in the column pipe and an axially extending chain connected to the pump and configured to move the pump in the column pipe.

A velocity control device for controlling the velocity of a load on a flexible tension member. The device can include a chassis having a chassis peripheral surface, with a portion of the chassis peripheral surface defining an exit aperture. The device can also include a capstan, the capstan having a proximal face joined to the chassis and a distal face separated at a distance from the proximal face. A peripheral capstan surface can be tapered from a greatest diameter near the distal face to a smallest diameter near the proximal face. The device can include a throttle, the throttle being attached to the chassis. The throttle can an interior surface defining an opening through which the tension member can pass with the interior surface being in at least partial contact with the tension member. Heat produced by kinetic energy in the flexible tension member is transferred to the throttle, and the change in system internal energy produces work in the form of a drag force on the flexible tension member.

A velocity control device for controlling the velocity of a load on a flexible tension member. The device can include a chassis having a chassis peripheral surface, with a portion of the chassis peripheral surface defining an exit aperture. The device can also include a capstan, the capstan having a proximal face joined to the chassis and a distal face separated at a distance from the proximal face. A peripheral capstan surface can be tapered from a greatest diameter near the distal face to a smallest diameter near the proximal face. The device can include a throttle, the throttle being attached to the chassis. The throttle can an interior surface defining an opening through which the tension member can pass with the interior surface being in at least partial contact with the tension member. Heat produced by kinetic energy in the flexible tension member is transferred to the throttle, and the change in system internal energy produces work in the form of a drag force on the flexible tension member.

A lift assembly includes an article to be lifted between a lowered position and a raised position, a drive element coupled to the article, a power mechanism coupled to the drive element, and a power transfer mechanism coupled between the power mechanism and the drive element. The power transfer mechanism includes control electronics having a first upward limit switch adapted to deactivate the power mechanism when the article is lifted to a first upward height, and a second upward limit switch adapted to deactivate the power mechanism when the article is lifted to a second upward height higher than the first upward height.

A lift assembly includes an article to be lifted between a lowered position and a raised position, a drive element coupled to the article, a power mechanism coupled to the drive element, and a power transfer mechanism coupled between the power mechanism and the drive element. The power transfer mechanism includes control electronics having a first upward limit switch adapted to deactivate the power mechanism when the article is lifted to a first upward height, and a second upward limit switch adapted to deactivate the power mechanism when the article is lifted to a second upward height higher than the first upward height.

A hoist system having a drum primarily self-contained within a batten, for raising and lowering lighting, sound equipment, curtains and the like in a performance environment. The hoist system may be adapted with safety mechanisms including an overload sensor and/or a slack line detector. The system may be provided in the form of a point hoist. The compact system is highly scalable to a variety of spaces and applications, including school and public theaters and concert halls, as well as some homes, private business, etc. Additional features include various cable management systems and trim adjustment mechanisms for use with the hoist system.