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.

An electric winch device includes a required braking force estimation section which estimates a required braking force required to stop a free-falling object at a position at an allowable stopping height; a braking force determination section which determines, out of an operational braking force, each of a first braking force to be borne by a braking device and a second braking force to be borne by a braking force which is generated in an electric motor due to consumption of regenerative power; and a control section which causes the braking device to apply the first braking force to a winch drum. The braking force determination section determines the first braking force to be a braking force equal to or greater than the required braking force when, at a time of stopping of the free-falling object, the operational braking force is equal to or greater than the required braking force.

An electric winch device includes a required braking force estimation section which estimates a required braking force required to stop a free-falling object at a position at an allowable stopping height; a braking force determination section which determines, out of an operational braking force, each of a first braking force to be borne by a braking device and a second braking force to be borne by a braking force which is generated in an electric motor due to consumption of regenerative power; and a control section which causes the braking device to apply the first braking force to a winch drum. The braking force determination section determines the first braking force to be a braking force equal to or greater than the required braking force when, at a time of stopping of the free-falling object, the operational braking force is equal to or greater than the required braking force.

A centrifugal brake mechanism for a controlled descent device, and a drum device employing it. The brake mechanism comprises a circular wheel configured and operable to rotate about an axis of rotation, an axle extending along and rotatable about the axis inside a central cavity of the wheel and having two or more parallel shaft rods extending inside the cavity substantially perpendicular to the axis of rotation, a gear system for transferring rotations of the wheel into counter-rotations of the axle, one or more brake elements each having two or more pass-through bores for slidably mounting over the two or more parallel shaft rods, two or more springs mounted over the parallel shaft rods between the brake element and the axle, and a friction enhancement mechanism for increasing friction forces between the brake elements and the inner wall the wheel responsive to increase in angular velocity of the wheel.

A centrifugal brake mechanism for a controlled descent device, and a drum device employing it. The brake mechanism comprises a circular wheel configured and operable to rotate about an axis of rotation, an axle extending along and rotatable about the axis inside a central cavity of the wheel and having two or more parallel shaft rods extending inside the cavity substantially perpendicular to the axis of rotation, a gear system for transferring rotations of the wheel into counter-rotations of the axle, one or more brake elements each having two or more pass-through bores for slidably mounting over the two or more parallel shaft rods, two or more springs mounted over the parallel shaft rods between the brake element and the axle, and a friction enhancement mechanism for increasing friction forces between the brake elements and the inner wall the wheel responsive to increase in angular velocity of the wheel.

An electric winch device includes a required braking force estimation section which estimates a required braking force required to stop a free-falling object at a position at an allowable stopping height; a braking force determination section which determines, out of an operational braking force, each of a first braking force to be borne by a braking device and a second braking force to be borne by a braking force which is generated in an electric motor due to consumption of regenerative power; and a control section which causes the braking device to apply the first braking force to a winch drum. The braking force determination section determines the first braking force to be a braking force equal to or greater than the required braking force when, at a time of stopping of the free-falling object, the operational braking force is equal to or greater than the required braking force.

An electric winch device includes a required braking force estimation section which estimates a required braking force required to stop a free-falling object at a position at an allowable stopping height; a braking force determination section which determines, out of an operational braking force, each of a first braking force to be borne by a braking device and a second braking force to be borne by a braking force which is generated in an electric motor due to consumption of regenerative power; and a control section which causes the braking device to apply the first braking force to a winch drum. The braking force determination section determines the first braking force to be a braking force equal to or greater than the required braking force when, at a time of stopping of the free-falling object, the operational braking force is equal to or greater than the required braking force.

The invention relates to a method for collision monitoring of a load which is fastened to a cable of a work machine, in particular a crane, wherein the work machine has a turntable that is rotatable about a vertical axis of rotation, a jib which is connected to the turntable and over which the cable is guided, and at least one sensor for detecting a current position and/or movement of at least one movable component of the work machine. According to the invention, a predicted braking trajectory of a defined point of the work machine is determined based on the sensor data, and a predicted braking trajectory of the load is calculated on the basis of the determined braking trajectory of the defined point and a computational model. The invention further relates to a work machine, in particular a crane, comprising a turntable that is rotatable about a vertical axis of rotation, a jib which is connected to the turntable and over which a cable is guided, and a control unit which receives data relating to a current position and/or movement of a load suspended on the cable, from at least one sensor of the work machine, wherein the control unit is configured to carry out the method according to the invention. The invention further relates to a corresponding computer program product.

The invention relates to a method for collision monitoring of a load which is fastened to a cable of a work machine, in particular a crane, wherein the work machine has a turntable that is rotatable about a vertical axis of rotation, a jib which is connected to the turntable and over which the cable is guided, and at least one sensor for detecting a current position and/or movement of at least one movable component of the work machine. According to the invention, a predicted braking trajectory of a defined point of the work machine is determined based on the sensor data, and a predicted braking trajectory of the load is calculated on the basis of the determined braking trajectory of the defined point and a computational model. The invention further relates to a work machine, in particular a crane, comprising a turntable that is rotatable about a vertical axis of rotation, a jib which is connected to the turntable and over which a cable is guided, and a control unit which receives data relating to a current position and/or movement of a load suspended on the cable, from at least one sensor of the work machine, wherein the control unit is configured to carry out the method according to the invention. The invention further relates to a corresponding computer program product.