A lift yoke

Abstract

 In order to adjust the lift point of the lift yoke or spreader to be right over the centre of gravity for a container to be lifted, a suspension frame (6) is pivotally attached to the center beam (1) of the spreader. The frame (6) may be tilted by means of a double-acting hydraulic cylinder (8) between the center beam and the suspension frame.

Description

Technical Field

[0001] This invention relates to a lift yoke or spreader for containers.

Background of the Invention

[0002] It is quite common to suspend a lift yoke or spreader with its attached container in one point (by one lift block). If the centre of gravity for the spreader with the container is not vertically below this point, the container will be inclined or take a position that deviates from the desired horizontal position. This may be dangerous if the inclination is such that the load in the container starts to move.

[0003] It is accordingly necessary to see to it that the lifting point (the lift block) may be adjusted to be right over the centre of gravity for the container and spreader.

[0004] In a known design this is accomplished in that the central beam or frame of the spreader is provided with a suspension tower for connection to the lift block. This suspension tower is longitudinally movable relative to the central beam of the spreader. In the specific design the movement of the suspension tower is accomplished by means of electric motors. This design is complex, heavy and expensive.

The Invention

[0005] A simpler and lighter design is according to the invention obtained in that a suspension frame is pivotally attached to a center frame of the yoke, so that its upper end where the lifting force is to be applied is movable in the longitudinal direction of the yoke, and in that means are provided to pivot and lock the suspension frame relative to the yoke.

[0006] As is apparent these means may be of different kinds. It is, however, preferred that a double-acting hydraulic cylinder is pivotally attached to the center beam and the suspension frame, respectively.

Brief Description of the Drawing

[0007] The invention will be described in further detail below reference being made to the accompanying drawing, which in a perspective view shows a container lift yoke or spreader according to the invention.

Detailed Description of a Preferred Embodiment

[0008] A lift yoke or spreader consists basically of a central beam 1 and two extending beams 2, each with a transverse beam 3 and end pieces 4 with means for removable connection to a container 5 indicated with dashed lines.

[0009] A suspension frame 6 is pivotally attached to the central beam 1. The pivot axis 7 of the suspension frame 6 is perpendicular to the longitudinal axis of the beams 1 and 2. The angular position of the suspension frame 6 may be adjusted by means of a double-acting hydraulic cylinder 8 pivotally attached to the frame 6 and to the central beam 1, respectively.

[0010] A lift block 9 of a crane (not shown) is pivotally attached to the upper end of the suspension frame 6.

[0011] The suspension frame 6 is shown in the upright position in full lines and in two tilted positions with dashed lines. In a practical case the distance between the lift block 9 in the upright and either maximally tilted position is 1.2 m.

[0012] When the lift spreader has been attached to a container 5 and it appears at a commencing lifting operation that the unit consisting of the spreader and the container is not horizontal, indicating that the centre of gravity of the container 5 is not right below the lift block 9, it is possible to tilt the suspension frame 6 until the lift block 9 is right over the center of gravity for the container, which thereafter can be lifted in a completely horizontal position.

Claims

1. A lift yoke for containers, characterized in that a suspension frame (6) is pivotally attached to a center beam (1) of the yoke, so that its upper end where the lifting force is to be applied is movable in the longitudinal direction of the yoke, and in that means (8) are provided to pivot and lock the suspension frame relative to the yoke.

2. A lift yoke according to claim 1, characterized in that said means is a double-acting hydraulic cylinder (8) pivotally attached to the center beam (1) and the suspension frame (6), respectively.

Drawing