EP0634987B1

EP0634987B1 - A lifting device and method

Info

Publication number: EP0634987B1
Application number: EP93905364A
Authority: EP
Inventors: Jim Wilhelm Willberg
Original assignee: Partek Paroc Oy AB
Current assignee: Paroc Group Oy AB
Priority date: 1992-04-06
Filing date: 1993-03-10
Publication date: 1999-11-24
Anticipated expiration: 2013-03-10
Also published as: DE69327097D1; DE69327097T2; EP0634987A1; FI89473C; CN1033078C; WO1993020004A1; ATE186898T1; JPH07505353A; CN1078211A; ES2139652T3; DK0634987T3; FI89473B; FI921503A0; JP3136326B2; DE634987T1

Abstract

The invention relates to a device for lifting building elements, which elements are comprised of a resilient core portion (8) as well as of a surface layer (9, 9') covering it on both sides. The device is comprised of a frame structure (1), of at least one arm member (2) extending through the frame and movable relative to the frame, of a gripping member arranged at one end of the arm member and insertable under a surface layer on top of a core layer (8), of locking members arranged on the opposite end of the arm member (2) for locking the arm member (2) into a lifting position, as well as of members for supporting the frame structure (1) on a surface layer (9') opposite to the element to be lifted.

Description

The invention relates to a method and a device for lifting building elements or corresponding panel-like members, which members are at least partially comprised of a core portion of a resilient material as well as of a plate-like surface layer covering this core portion on both side surfaces, which surface layer on at least one element edge is bent over a part of the thickness of the core portion.
A building element, to whose lifting the inventive device is applicable, may be comprised e.g. of a resilient core portion made of e.g mineral wool fiber, each flat surface of which is coated with a metal sheet glued onto the surface of the wool plate. The treatment of such building elements has to be gentle for preventing the damaging of the panels, and clamp jaw type lifting devices known per se cannot be applied to lifting these panels. Different gripping elements have been developed for lifting said inherently light panels, which are fixed to the flat surfaces of the elements by suction pads.
In spite of the relative lightness of the elements to be lifted, the number of the suction pads has to be fairly large for ensuring a sufficient lifting safety and for taking into account the effect of factors possibly disturbing the fixing of the suction pads. Furthermore, these gripping elements of lifting devices require a sufficient free space at least in the area of one surface of the panel for fixing the gripping member to the flat surface of the panel to be lifted.
Said drawbacks may be eliminated by means of the inventive device and method, which make the gripping on the panel edge possible, in a certain embodiment even horizontally in a space essentially required by the panel thickness.
The essential characteristics of the method are described in the enclosed patent claim 1. The essential characteristics of the device are in turn described in the enclosed patent claim 3.
The invention is illustrated by means of the accompanying drawing, wherein
Fig. 1 shows an element to be lifted, on whose upper edge is placed an inventive device in the initial fixing step;
Fig. 2 shows the element to be lifted from the same direction, when the inventive device is fixed to the lifting position;
Fig. 3 shows the element from the direction of the flat surface, when the lifting device is fixed to the upper edge in the lifting position; and
Fig. 4 shows an inventive application for lifting roof elements.
A panel-like building element, which is of a type that may be lifted by means of the inventive device, is comprised of a core portion 8, whose thickness forms an essential part of the element thickness, as well as of a plates 9, 9' covering the core portion on both sides. The core portion 8 may be made e.g. of a mineral wool mat having a suitable strength, which is coated with a metal sheet.
The upper edge of the wall element of Fig. 1-3 is designed for achieving a joint structure such that each cover plate 9, 9' extends by some distance above the core portion 8 and is bent towards the core portion for forming a bead extending along the length of the element. The bead structures extend by some distance towards the center part of the element, but leave an essential part of the upper edge of the core portion 8 free. In the embodiment shown, each bead forms a tongue 10 in the longitudinal direction of the plate, and a matching groove shape corresponds to this tongue on the lower edge of the upper element.
In the roof element of Fig. 4, the joining edge is designed to deviate from the wall elements. A plate cover 9 forming the lower surface of the element is extended, corresponding to the wall elements, partly on top of the core portion 8, but the edge of a plate cover 9' forming the upper surface is in turn bent outwards for forming a water seam between two element plates to be placed adjacent to each other. Also a tongue and groove structure 10' of the lower surface deviates from the tongue and groove structure of the lifting edge of the wall element and corresponds in fact better to the tongue and groove structure of the lower edge of the wall element, which tongue and groove structure has a longitudinal groove.
First of all, the inventive lifting device is comprised of a beam 1 forming a frame. The width of this beam in the lifting device, which is intended for lifting wall elements, preferably corresponds to the thickness of the wall element. In contrast, the width of the frame piece intended for lifting roof elements is not critical. In a device intended for lifting wall elements, the frame beam 1 may in turn have an optional length, but in a device intended for lifting roof elements, the length of the frame beam is defined by the thickness of the element to be lifted. On the frame beam 1 is mounted at least one gripping unit, which is comprised of a shaft or a corresponding member 2, which is preferably placed in a boring made in the middle of the width of the frame beam 1. The shaft 2 is in the boring provided with a movement clearance such that the shaft may be both turned and moved in its longitudinal direction relative to the frame beam 1.
At the other end of the shaft is placed a longitudinal, gripping claw 3 transverse relative to the longitudinal axis of the shaft. In a device intended for lifting wall elements, the gripping claw 3 is dimensioned by its width such that it may be placed in an intermediate space left by the beads of the surface plates 9 to be freely pressed against the upper edge of the core portion 8. The gripping claw 3 is by its length dimensioned such that it, when turned cross-wise relative to the longitudinal direction of the element, extends below at least one tongue and groove 10, preferably however such that it extends according to Fig. 1 and 2 below the bead of both tongue and grooves 10. In a device intended for lifting roof elements, the gripping claw 3 preferably protrudes only from one side from the shaft 2 and is dimensioned by its length such that when the location of the shaft 2 is taken into account, it extends below the bead of the tongue and groove structure 10' of the lower surface of the element.
In a device intended for lifting wall elements, the lower surface of the frame beam 1 is designed such that it follows the upper surface of the element to be lifted, i.e. longitudinal receiving grooves of the frame beam have been formed for the tongue shapes 10. In a device intended for lifting a roof element, these tongue and grooves are not needed, but instead, it is advisable to provide the end of the frame beam 1 containing the gripping claw 3 with a cam 1' extending to the side of the gripping claw of the frame beam 1, which cam 1' is dimensioned to fit into the groove of the tongue and groove 10' of the lower surface of the roof element.
In a device intended for lifting roof elements, at one end of the frame beam 1 is mounted a special gripping member 11 for gripping a water seam 12 of the upper surface of the roof element. This gripping member 11 is formed into a hook-like member, which may be fixed to the frame beam 1 by means of a shaft 2 placed in a corresponding manner as the gripping claw 3 located at the other end of the frame beam. The gripping member 11 is dimensioned such that it may be hooked behind a flange edge 12' of the water seam, before the frame beam is mounted in the fixing position of the gripping claw 3 against the edge of the roof element. In place of a hook-like gripping member 11, the structure may also include a member of another type for gripping the element to be lifted, e.g. a suction pad gripping the plate 9' forming the surface layer.
When the lifting device is set into the lifting position, in the wall-element lifting device according to Fig. 1-3, the gripping claw 3 is first turned in the direction of the frame beam 1 and the frame beam 1 is then placed on top of the upper edge of the element according to Fig. 1. After this, the shaft 2 extending through the frame beam and the gripping claw 3 at the end thereof are pressed against the upper surface of the resilient core layer 8 of the element. The resilient core layer somewhat springs, whereby the gripping claw 3 may be caused to press inside the element to such an extent that it may be turned into a position in the thickness direction of the element. In this position, the claws of the gripping member extend below the beads of the bent tongue and grooves 10 of the surface layers of the element according to Fig. 2. A lifting arm 5 is then turned into its position in the direction of the frame beam 1 and locked into this position into a locking member 6 fixed to the frame beam 1. This locking member preferably acts simultaneously with a lifting eye of the device.
A device intended for lifting the roof element is in turn placed cross-wise relative to the element to be lifted, whereby the above-mentioned hooking fixing of the gripping member 11 is first performed behind the flange 12'. After this, the cam 1' of the frame element is pressed into the tongue and groove of the element, the shaft 2 and the gripping claw 3 at the end thereof are pressed against the resilient core layer 8, in a manner corresponding to that described above, and the shaft 2 is turned such that the gripping claw 3 positions below the bead of the tongue and groove structure 10'. In place of said turnable realization, also such a structure may be used in a device intended for lifting roof elements, in which structure the a part corresponding to the shaft 2 may be moved in a longitudinal gap of the frame beam in the longitudinal direction of the frame beam. In this case, the gripping claw 3 may be in a position according to Fig. 4 already at the time as the claw is pressed against the upper surface of the core portion 8. The claw is slided in this position under the tongue-and-groove bead and locked in the lifting position by means of members also shown in Fig. 4.
The fixing of the lifting device to the edge of the element to be lifted may be ensured by means of the characteristic feature of the inventive device, according to which an hinged member 4 between the lifting arm 5 and the shaft 2 is formed into a clamping member by means of wedge surfaces 4'. By means of these wedge surfaces, it is possible to achieve for the shaft 2 a slight ascending movement, when the lifting arm 5 is turned into a horizontal position, which ascending movement is sufficient for tightening the gripping members, such as the tongue-and-groove bead and the water seam, of the element to be lifted between the frame beam and the gripping claw 3, correspondingly between the frame beam 1 and the gripping member 11.
The lifting device intended for lifting wall elements includes above-mentioned lifting pairs - a shaft 2, a gripping claw 3, an hinged member 4 and a lifting arm 5 - preferably in pairs in a manner shown in Fig. 3, in cooperation with the same locking member 6. By means of this arrangement, the lifting device may be made into a uniformly operating tool. However, other arrangements are naturally possible within the scope of the invention, such as only one lifting subunit per lifting device. The lifting device may be dimensioned also longer such that it comprises two or more lifting subpairs, which are located at a suitable distance from each other.
A device intended for lifting a roof element naturally comprises only parts shown in Fig. 4, whereby preferably several devices may be used for gripping elements to be lifted at points located at a distance from each other.
Deviating from the embodiments described above, in place of the beam-like frame 1 described to be uniform may also be used a frame structure of another type, such as a box structure made of plate or a structure made of plate by bending. Various framework-type frame structures are also possible.
In place of the shaft 2 mounted on the frame may be used a freely formed arm-like member extending through the thickness of the frame, which may be formed at its one end such that it directly forms a gripping claw 3, and at its opposite end such that it directly forms a lifting arm 5 or a corresponding member, by means of which this arm member may be locked onto the frame. In contrast to what has been described above, the arm member 2 may be mounted on the frame 1 e.g. to be tilted relative to the frame, whereby in one tilting position the gripping claw 3 in the arm member 2 may be pushed under the cover layer bead and in the other tilting position the gripping claw 3 locks the cover layer bead against the frame, in which position the arm member is locked onto the frame from its opposite end. The locking of the arm member 2 onto the frame may also be performed directly without using the lifting arm described, and in this case e.g. to a lifting eye 6 or to some other point of the frame.
In place of the above-mentioned turning and tilting movements of the shaft or the arm member 2 or togerher therewith, said part may also be slidable relative to the frame, e.g. in a groove extending through the frame. E.g. in the realization of Fig. 4, the gripping claw may then be pushed under the surface layer bead without the turning movement of the shaft 2 and the gripping claw 3, whereby the gripping claw 3 may be designed ski-like for facilitating the pushing movement and for avoiding surface damage to the core layer.
As shown above, it is sufficient in many applications that the lifting device is provided with a structure formed by the gripping claw 3 or a corresponding arm section 2 for gripping only one surface layer bead. The opposite end of the lifting device may be supported on the opposite side of an element edge in various ways, of which one alternative is shown in Fig. 4 as a hook-like gripping member 11. In place of the member 11 may be used also a gripping member of another type, e.g. a suction pad structure to be fixed to the surface layer 9'. If also the surface layer 9' is extended on top of the core portion 8, it may then be considered a gripping member to be first inserted under the surface layer bead, e.g. a hook or the like protruding from the frame 1 towards its one end, which member is first inserted under a bead formed of the surface layer 9'. After this, the opposite end of the frame is locked e.g. by means of a gripping claw 3 functioning according to Fig. 4 under the bead of the opposite surface layer 9.

Claims

A method for lifting a panel-like building element at least partly comprised of a resilient core layer (8) as well as of surface layers (9, 9') covering it on both faces, in which element at least one of the surface layers is extended on one edge of the element and bent over to cover part of the corresponding edge of the core layer (8), forming thereby a bead, characterized in that a lifting device is used which is provided with elements to grip from under the bead of the at least one of the surface layers (9, 9') extending on top of the edge of the core layer (8), and with elements to secure the gripping.
A method according to claim 1, characterized in that the core layer (8) is compressed in the planar direction of the element for gripping under the bead of the cover layers (9, 9').
A device for accomplishing the method of claim 1, which device is comprised of a frame structure (1), of at least one arm member (2) extending through the frame structure and movable relative to said structure, of a gripping member (3) arranged at one end of the arm member and insertable under the bead of the at least one surface layer (9) on top of a core layer (8), of locking members arranged on the opposite end of the arm member (2) for locking the arm member (2) into a lifting position, as well as of a lifting arm (5), characterized in that the locking members of the arm member (2) comprise a hinged member (4) provided with a wedge member (4') for moving the arm (2) member axially upon rotation of the hinged member, and tighten thereby the gripping member (3) and the bead of the at least one surface layer (9) against the frame structure (1).
A device according to claim 3, characterized in that the hinged member (4) is a part of the lifting arm (5) articulated fixed to the frame (1).
A device according to claim 4, characterized in that the lifting arm (5) is lockable to the frame (1) in a lifting position.
A device according to any of the preceding claims 3 to 5, characterized in that the frame (1) contains members for bearing the frame structure on an other surface layer (9') opposite to the at least one surface layer (9) of the element to be lifted.
A device according to claim 6, characterized in that the members for bearing the frame structure on an other surface layer (9') are comprised of members gripping under the bead of said layer (9').
A device according to claim 3, characterized in that the arm member (2) is mounted on a gap extending through the frame structure (1) and is slidable in the gap in a direction transverse to the lifting direction.