IP Library › Granted Patent US 12,606,422
Granted Patent B2
US 12,606,422 · App. 18/360,578 · Granted Apr 21, 2026

Lifting gear, and method for determining slack rope on the lifting gear

Inventors: Clemens Maier (Munderkingen, DE); Tobias Englert (Burgrieden, DE)
Assignee: Liebherr-Werk Biberach GmbH
B66C13/105B66C13/16
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Quick Facts
Patent No.
US 12,606,422
App. No.
18/360,578
Granted
Apr 21, 2026
Kind
B2
Abstract

The present invention relates to lifting gear comprising a hoist rope, on which a load-receiving means is provided for receiving and lifting a load, and a determining device for determining slack rope on the hoist rope, wherein the aforementioned determining device comprises an inclination sensor system for detecting an inclination and/or a tilt rate and/or a tilt acceleration of the load-receiving means and provides a slack-rope signal if the detected inclination and/or tilt rate and/or tilt acceleration of the load-receiving means exceeds a predetermined limit value.

Claims (21)

1 . A lifting gear comprising:

a hoist rope;

a load receiver on the hoist rope, wherein the load receiver is configured to receive and lift a load; and

a determining device for determining slack rope on the hoist rope;

wherein the determining device comprises an inclination sensor system for detecting an inclination and/or a tilt rate and/or a tilt acceleration of the load receiver and is configured to provide a slack-rope signal if the detected inclination and/or tilt rate and/or tilt acceleration of the load receiver exceeds a predetermined limit value; and

wherein the determining device comprises an acceleration sensor system for detecting a first acceleration at a hoist winch and/or a hoist drive for the hoist rope and for detecting a second acceleration at the load receiver, and wherein the determining device is configured to provide the slack-rope signal when one of the first or second accelerations deviate from the other of the first or second accelerations above a predetermined amount.

2 . The lifting gear of claim 1 , wherein the inclination sensor system is configured to detect at least inclinations and/or tilt rates and/or tilt accelerations with respect to a horizontal tilting axis, wherein the inclination sensor system is configured to operate bi- axially or triaxially.

3 . The lifting gear of claim 1 , wherein the inclination sensor system comprises at least one sensor element attached to the load receiver.

4 . The lifting gear of claim 1 , wherein the inclination sensor system comprises an inertial measurement unit for providing acceleration signals and rotation rate signals to the load receiver.

5 . The lifting gear of claim 1 , wherein the determining device comprises a load sensor system for detecting the load acting on the hoist rope and/or for detecting a hoist rope force, and wherein the determining device is configured to provide a slack-rope signal when the detected load and/or the detected hoist rope force drops below a predetermined limit value and/or a drop rate of the detected load and/or hoist rope force exceeds a predetermined limit value.

6 . The lifting gear of claim 5 , wherein the determining device is configured to provide the slack-rope signal if the limit value for the detected load and/or hoist rope force is reached and the limit value for the inclination and/or a tilt rate and/or a tilt acceleration of the load receiver is reached.

7 . The lifting gear of claim 6 , wherein the determining device is configured to take into account adapted limit values for the inclination and load signals when the signals of the inclination sensor system and the load sensor system are taken into account in a linked manner.

8 . The lifting gear of claim 1 , wherein the load sensor system comprises a tensile force sensor and/or load sensor at an attachment point of the hoist rope.

9 . The lifting gear of claim 1 , wherein the load sensor system comprises a load sensing axis on a lower block of the load receiver or on another deflection pulley of a hoist rope drive.

10 . The lifting gear of claim 1 , wherein the acceleration sensor system on the hoist winch and/or the hoist drive comprises a rotational rate sensor and optionally a winding layer sensor and on the load receiver has an acceleration sensor for detecting upright accelerations, and wherein the acceleration sensor comprises an inertial measurement unit.

11 . The lifting gear of claim 1 , wherein the determining device is configured to take into account a proportionality factor corresponding to a course of the hoist rope when comparing the deviation of the first and second accelerations, and wherein the course of the hoist rope comprises a hoist rope reeving.

12 . The lifting gear of claim 1 , further comprising an accelerometer for determining an acceleration of the load receiver and/or the load from a load signal of a load sensor system on the basis of the equation F=m*a from the changes of the load signal.

13 . The lifting gear of claim 1 , further comprising a control device configured to automatically switch off and/or block a hoist drive and/or other lifting gear drives in the presence of the slack-rope signal.

14 . The lifting gear of claim 13 , wherein the control device is configured to only allow hoist movements that tension the hoist rope when the slack-rope signal is present.

15 . The lifting gear of claim 14 , wherein the hoist movements that tension the rope comprise a hoist up movement of the hoist drive and/or a luffing up movement of a boom.

16 . The lifting gear of claim 1 , wherein the determining device comprises a wireless communication interface for wirelessly receiving sensor signals.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 29, 2023
From: MAIER, CLEMENS; ENGLERT, TOBIAS
To: LIEBHERR-WERK BIBERACH GMBH
Reel/Frame 064742/0992 →
Priority Claims (2)
DE 10 2021 101 800.5 · Jan 27, 2021 · national
DE 10 2021 103 934.7 · Feb 19, 2021 · national
Continuity (2)
Continuation PCTEP2022051897 · Jan 27, 2022
Related Publication 20230391588A1 · Dec 7, 2023
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