EP1600418A1

EP1600418A1 - A lifting yoke and a method of lifting wall elements

Info

Publication number: EP1600418A1
Application number: EP05010187A
Authority: EP
Inventors: Jan- Christer Mäki
Original assignee: Plannja AB
Current assignee: Plannja AB
Priority date: 2004-05-26
Filing date: 2005-05-11
Publication date: 2005-11-30
Also published as: SE0401335L; SE0401335D0; NO20051949L; SE525633C2; NO20051949D0

Abstract

A lifting yoke for lifting wall elements has a U-shaped frame on the legs 12, 13 of which are mounted clamping plates 17, 18. A lifting means in the form of a loop 16 of tape is connected to one leg 12 in association with the attachment of the clamping plate 17 to the outermost part of the leg. The lifting yoke is introduced from the side over one end of the wall element 30 such that the clamping plates are located at equal distances from the two edges of the wall element. Since the lifting force is applied offset, the clamping plates will clamp the wall element between them and the force of clamping will increase when the lifting force increases.

Description

Technical Area

The present invention relates to lifting yokes and a method for lifting wall elements.

Object of the Invention

It is an object of the invention to demonstrate a simple and cheap lifting yoke that allows simple and safe assembly of wall elements, in particular light wall elements that are assembled standing.

This is achieved with a lifting yoke that has a U-shaped frame on the legs of which clamping plates are mounted, and a lifting means connected to one of the legs in association with the attachment of the clamping plate (17) to the outer part of the leg.

Brief description of the drawings,

The drawings 1-3 show a lifting yoke as an example of the invention.

Figure 1 is a view as specified by the arrows 1-1 in Figure 2,

Figure 2 is a view as specified by the arrows 2-2 in Figure 1, and

Figure 3 is a view as specified by the arrows 3-3 in Figure 2.

Figure 4 shows a stack of wall elements where lifting of the uppermost element has commenced,

Figure 5 corresponds to Figure 4, but shows the lifting somewhat later,

Figures 6 and 7 show the lifted wall element in an upright position.

Detailed description of illustrated embodiment of the lifting yoke

The lifting yoke shown in Figures 1-3 comprises a U-shaped frame that consists of two

legs

12, 13 of tubular steel joined by a base or end-section 14, also in the form of a tube. The three tubes are welded together to form the frame. The end-section supports a spike 15 that is parallel to the legs.

A lifting means 16 in the form of a loop of tape is attached to the end of the leg 12 adjacent the attachments for

clamping plates

17,18. The attachments of the clamping plates both have a

part

19, 20 that is part of a circle and that is mounted on bearings on the relevant leg such that it can turn to a limited extent relative to the leg. These parts that are parts of circles are held in place axially on the legs through screws 21 screwed into the legs.

The clamping plates have a

soft surface cover

22, 23 of cellular rubber sheet and a similar

soft cover

24, 25 is glued onto a part of the legs.

A plate hook 26 with a spike 27, which is identical to the spike 15, is attached to the leg 12 by a tape 28. The hook is adapted to the thickness of the wall element.

Description of use of the illustrated lifting yoke

Figure 4 shows a stack of wall elements of sandwich type, which consist of a core of insulation, for example mineral wool insulation or expanded polystyrene, onto whose sides a surface layer of sheet metal has been glued. The sheet sides are terminated by folds, not shown in the diagram, that form tongues and grooves. The uppermost wall element 30 is shown with one end raised, either manually or in another manner, and a block 31 holds this end at its elevated position such that the lifting yoke that has been described can be introduced from the side on the wall element 30 as shown. The length of the

legs

12, 13 of the lifting yoke has been adapted such that the clamping plates are placed centrally on the sides of the wall element. The distance between the clamping plates of the

lifting yoke

17, 18 is to be somewhat greater than the thickness of the wall element. When lifting by the loop 16 of tape is carried out, the wall element 30 will initially be supported by the lower clamping plate 18; and when it has been lifted to approximately the position shown in Figure 5 the block 31 is moved to the other end, as is shown in the drawing, and the lifting yoke is lowered such that a protective plate 32 can be introduced under the farther end of the wall element, before lifting is continued. The surface covering of the clamping plates provides high friction against the wall element, and the spike 15 that penetrates the insulation of the wall element also provides a holding force during the first part of the lifting operation, before the clamping plates clamp the wall element between them, something that takes place when the yoke achieves a certain oblique position relative to the wall element. The friction then increases as the obliqueness increases since the force that acts normally between the clamping plates and the wall element increases. The lifting force applied eccentrically or offset by the loop 16 of tape thus gives rise to the friction, and the frictional force becomes greater for a heavier wall element. The wall element will be obliquely suspended when it achieves an upright position, as is shown in Figures 6 and 7, but this obliqueness does not disturb the mounting of the wall element when it is manually pressed against wall elements that have been previously mounted. If required, an assembly trolley can be placed under the lower end in order to facilitate displacement.

The spike 15 is inserted into the insulation at one end of the wall element and the spike 27 of the plate hook 26 is inserted into the insulation at the other end of the wall element. The spike 27 has no function during normal lifting, this spike solely provides extra security.

Claims

A lifting yoke for lifting wall elements, characterised by a U-shaped frame on the legs (12, 13) of which clamping plates (17, 18) are mounted, and a lifting means (16) connected to one of the legs (12) in association with the attachment of the clamping plate (17) to the outer part of the leg.
The lifting yoke according to claim 1, characterised in that the legs (12, 13) of the frame are tube-shaped and that the clamping plates (17,18) have attachments (19, 20) that are mounted with bearings on the legs such that the clamping plates can be rotated relative to the legs.
The lifting yoke according to claim 1 or 2, characterised by a spike (15) at the base (14) between the legs, where this spike is parallel to the legs.
A method of lifting a wall element from a stack of lying wall elements, characterised in one end of the wall element (30) is initially lifted and a U-shaped lifting yoke (12-14) is introduced from the side of the wall element over the wall element such that clamping plates (17, 18) on the lifting yoke are placed one on each side of the wall element, and in that the lifting yoke is subsequently lifted by one of its legs such that the lifting yoke is rotated relative to the wall element during the lifting, which leads to the clamping plates being clamped onto the sides of the wall element and holding the wall element fixed by the force of friction.