A bottom block assembly includes a bottom block defining a cavity and at least one opening passing through a portion of the bottom block. The assembly further includes a plurality of sheaves disposed at least partially within the cavity, each sheave having a central opening. The assembly further includes a sheave pin passing through the at least one opening in the bottom block and the central openings in the sheaves to rotatably couple the plurality of sheaves to the bottom block. The assembly further includes a plurality of captivating frame assemblies to be coupled to the plurality of sheaves, each of the plurality of captivating frame assemblies including a housing and a plurality of rollers rotatably mounted to the housing. Each captivating frame assembly is associated with a corresponding one of the sheaves. The assembly further includes a plurality of wires for coupling the plurality of captivating frame assemblies to the plurality of sheaves. Each wire is reeved around one of the sheaves and reeved through the corresponding captivating frame assembly.

A magnetizer configured to form a main magnetic flux path so as to include a set interval in an axial direction of a wire rope includes a first pole piece and a second pole piece, which are arranged so as to sandwich the set interval therebetween, each have a U-shaped cross section which is formed so as to surround the wire rope in a circumferential direction of the wire rope for about a turn without coming into contact with the wire rope. When the wire rope is magnetized by the magnetizer, a leakage magnetic flux generated from the wire rope damaged portion is detected by a magnetic sensor.

A magnetizer configured to form a main magnetic flux path so as to include a set interval in an axial direction of a wire rope includes a first pole piece and a second pole piece, which are arranged so as to sandwich the set interval therebetween, each have a U-shaped cross section which is formed so as to surround the wire rope in a circumferential direction of the wire rope for about a turn without coming into contact with the wire rope. When the wire rope is magnetized by the magnetizer, a leakage magnetic flux generated from the wire rope damaged portion is detected by a magnetic sensor.

A system for providing safety to a hoist having a hook and a chain. The system includes a safety cable threaded through an opening of the hook or an object to be lifted. The system includes a connector connected to the safety cable and the chain such that when the hook and the chain of the hoist are disconnected, the object remains connected to the chain via the connector and safety cable. The connector includes a base portion having a chain opening configured to receive the chain, and a first cable opening configured to receive the safety cable. The connector includes a top portion configured to be coupled to the base portion and cover a portion of the chain opening such that the base portion and the top portion, when coupled together, remain at a substantially fixed position along the length of the chain.

The present invention relates to a crane with a height-adjustably mounted control or personnel stand that can be lifted and lowered by at least two lifting elements, wherein the two lifting elements are articulated to a balancing rocker that is mounted on a rocker bearing head connected to the control or personnel stand so as to be luffable about a horizontal pivot axis, wherein a monitoring and/or safety device is provided to monitor and/or ensure the safety of the control stand. According to the invention, the pivot axis is configured as a measurement axis for detecting the load state of the luffable bearing of the balancing rocker and for providing a load signal to the monitoring and/or safety device.

The present invention relates to a crane with a height-adjustably mounted control or personnel stand that can be lifted and lowered by at least two lifting elements, wherein the two lifting elements are articulated to a balancing rocker that is mounted on a rocker bearing head connected to the control or personnel stand so as to be luffable about a horizontal pivot axis, wherein a monitoring and/or safety device is provided to monitor and/or ensure the safety of the control stand. According to the invention, the pivot axis is configured as a measurement axis for detecting the load state of the luffable bearing of the balancing rocker and for providing a load signal to the monitoring and/or safety device.

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 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, a hoisting apparatus with said hoist and a method for securing a hoist. A hoist body having a drive mechanism for raising or lowering a hoist chain or a hoist cable is suspended from a support device by a hoist support. A safety device having a loosely arranged coupling element and a damping element is mounted between the hoist body and the support device. If the hoist support is released, the hoist body can drop by a drop height until the coupling element becomes taut. The damping element then damps the fall under the load of the hoist body, the hoist chain and whatever load is suspended from it.

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.