GB2090192A - Method and apparatus for the manufacture of hollow elements from concrete - Google Patents

Abstract

The invention provides a method of making hollow elements from concrete, comprising a first concrete slab (33) and a second concrete slab (36) with spacer elements (35) between them. The slabs are formed on casting surfaces (1, 2) located next to each other or one above the other, the first slab being provided with spacer elements (35) and, after being sufficiently set, being reversed above the second slab. The distance between the slabs is then reduced to an extent that spacer elements (35) force themselves into the concrete of the second slab, which is still soft, the second slab being compacted and the element allowed to set. The invention also provides an apparatus for performing this method comprising a tilting floor (5) mounted for up-and- down movement and rotation about its horizontal axis, positioned above a casting surface (2). <IMAGE>

Description

SPECIFICATION Method and apparatus for the manufacture of hollow elements from concrete This invention relates to a method of making hollow elements from concrete, which comprises making a first concrete slab and a second concrete slab, and placing one on the other with spacer elements between them, and also to apparatus for making such elements.

Prior methods and apparatus for making hollow wall elements are disclosed in Dutch patent applications 72,06870 and 78,09307. In the known method, two side-by-side beds are used, each forming falsework in which a plurality of concrete siabs can be formed, located one behind the other, after the desired reinforcement has been placed in position. After being sufficiently set, the concrete slabs formed in one bed are tilted over about their longitudinal side adjacent to the other bed to be laid, with an interposed lattice, on top of the concrete slabs to be formed in the other bed, which is provided with concrete mortar, so that the lattice, preferably already partially embedded in the slabs of the one bed, can enter the mortar of the other bed. After complete setting, the product is a wall element comprising two spaced slabs interconnected by a lattice.

It is an object of the invention to improve the prior method and apparatus so that among other things, the work can be done faster, and more freedom is given as regards the arrangement of the apparatus and the dimensions of the concrete slabs.

According to the invention there is provided a method of making hollow elements from concrete, which comprises making a first concrete slab and a second concrete slab and placing one upon the other with spacer elements between them, wherein the concrete slabs are formed on casting surfaces, the first slab being provided with spacer elements and, after being sufficiently set, being turned over above the mortar bed of the second slab, whereafter the vertical distance between the two slabs is reduced to such an extent that the said spacer elements force themselves partially into the concrete of the second slab, which at that moment is still sufficiently soft, in which position, after compaction of the second slab, the composite element is allowed to set further.

The casting surfaces may be located next to each other or one above the other.

The invention will now be described with reference to the accompanying drawings, in which: Fig. 1 illustrates diagrammatically the basic idea of the present invention; Fig. 2 shows, diagrammatically, and in simplified form, a side-elevational view of an apparatus for the application of the method according to the present invention; and Fig. 3 partially shows a modification of the apparatus shown in Fig. 2.

Fig. 1 shows, in cross-sectional view, elongate beds 1 and 2, on to which concrete can be cast for forming one or more concrete slabs.

The beds accordingly serve as falsework, in known manner, and after the removal of the ready concrete elements can be re-used.

Placed over bed 2 is a frame 3 bridging the bed, which frame is substantially inversely U-shaped in end elevational view, the legs 4 of the U-shape being wheeled and supported on rails on opposite sides of the bed (see Fig. 2).

Suspended in the frame, in some suitable manner, is a tilting floor 5, which can be turned through at least 1800 about its longitudinal axis 6, as indicated by a curved arrow 7.

Naturally, the floor must be arranged far enough above bed 1 for such tilting movement to be possible.

Furthermore, bed 1 and floor 5 are movable towards and away from each other, as indicated diagrammatically by the double arrows 8.

According to the basic idea of the invention, the procedure for the manufacture of hollow concrete wall elements is as follows.

First, after suitable reinforcement has been placed in position, one concrete slab is cast on bed 1 between boundary surfaces 9 provided for the purpose. In the transverse direction, boundary surfaces are provided, too, but these are not shown. Moreover, in the concrete slab to be formed, spacer elements, preferably in the form of a lattice, are provided, which permanently project from the top of the concrete. When the concrete slab thus formed has sufficiently set, it is picked up, laid on the tilting floor, and temporarily fixed thereon by a clamping device or a vacuum device.

The slab can be picked up from bed 1 by means of an overhead travelling crane in the production hall, or a mobile lifting device H secured to frame 3' bridging bed 1 and coupled to the frame placed over bed 2, as indicated in dashed lines in Fig. 1.

Subsequently the tilting floor with the slab is tilted through 1 800, whereafter the distance between the slab and bed 2 is reduced to such an extent that the lattice extends into the concrete of the concrete slab cast on bed 2. At that moment the concrete on bed 2 should still be soft enough to ensure proper adherence to the lattice.

The desired final spacing between the tilting floor, or the slab, and bed 1 is maintained, and is adjustable, by means of adjustable spacer members 11 placed on opposite sides on, or beside, bed 2, and on which during the setting phase buffer blocks 1 2 of the tilting floor rest.

Naturally, the buffer blocks 12, too, may be adjustable, or simply be replaceable by buffer blocks of different height. In this way the spacing between the slabs of the hollow wall element being formed can be adjusted.

The method described, which permits various embodiments which will be described hereinafter, has the advantages of providing a great degree of freedom with regard to the arrangement and dimensioning of the slabs and beds, of needing one tilting device only, and of allowing faster operation.

Another advantage is that the lattice penetrates uniformly into the concrete of the lower slab.

Bed 1 has preferably such a length that a plurality of concrete slabs can be formed on it one behind the other, or consists of a plurality of like parts corresponding in length to the tilting device.

Furthermore, the frame is preferably provided with wheels arranged to travel on travelling surfaces, for example in the form of rails, mounted on opposite sides of bed 2 and possibly bed 1, so that after the formation of a first hollow wall element the frame can be moved to a next section of bed 2.

In this way the production of a second element can be started while the first element is still setting.

All this is shown in side-elevational view, in a simplified and diagrammatic fashion, in Fig. 2. As in the arrangement of Fig. 1 frame 2 is placed over bed 2 and possibly over bed 1 and rests on wheels 13, two of which are shown. The wheels rest in turn on rails 14 lying on opposite sides of the bed. The frame can accordingly be moved on the rails. For this purpose use can be made, for example, of electric or hydraulic motors (not shown) placed on the frame, or of a cable system arranged alongside the bed and secured to the frame, and coupled at one of the ends of the bed with a motor.

The frame further carries a motor or hydraulic reversing device 15, secured to a central upright 1 6 in a sliding bearing construction 1 7 movable upwardly and downwardly. The shaft 18 of motor 1 5 extends through the bearing construction and is connected to the tilting floor 5. Provided on the other side of the tilting floor, in alignment with shaft 18, is a similar shaft 19 journalled in a sliding bearing construction 21 mounted for upand-down movement in an associated central upright 20.

Accordingly, when motor 1 5 is activated the tilting floor can be tilted about shafts 1 8, 1 9 as indicated hy the curved arrow 7.

Furthermore, the assembly of tilting floor, shafts 1 8, 19, the sliding bearing constructions 17, 21 and motor 15 can move up and down in order that the tilting floor with the sufficiently set concrete siab and after rotation through 1 800 can be moved to a small distance from bed 2, and after releasing plate 5 from the concrete slab formed on it, plate 5 can be moved back up again, as indicated by the double arrow 8.

For this purpose, in the embodiment of Fig. 2, a motor 22 is mounted on a top girder of the frame.

Motor 22 drives a sprocket 23, which has two sets of teeth. One set of teeth co-operates with an endless chain 24 extending vertically alongside upright 1 6 and trained about a reversing gearwheel 25 at the lower end of upright 16, which chain is further coupled to sliding bearing construction 1 7. The second set of teeth cooperates with a horizontal endless chain 26 lapped around one set of teeth of a sprocket 27 having two sets of teeth, placed adjacent to the upper end of upright 20. The second set of teeth of sprocket 27 co-operates with a vertical endless chain 28 passed around a sprocket 29 placed adjacent to the lower end of upright 20 and further connected to sliding bearing construction 21.When the motor is activated, the tilting floor can thus be moved up and down by means of the chains described with the sliding bearing construction sliding in, or along, uprights 1 6, 20.

It is noted that the rotation and up-and-down movement of the plate can also be accomplished by different means. Thus, the rotation of plate 5, instead of by motor 15, could be realized by means of a motor placed elsewhere on the frame and coupled via gear wheels and/or racks and/or chains with the rotary shaft of plate 5, or a hydraulic rotation device may be used.

Similarly the up-and-down movement may be realized with modifications equivalent within the framework of the present invention.

According to one possible embodiment of the invention, bed 2 is sub-divided into a plurality of sections corresponding in dimensions to the tilting floor. These sections may each be provided with suitable means, for example, hydraulic piston-andcylinder combinations, for moving the sections up and down.

Such a construction offers the possibility for a section of bed 1 present under the tilting floor, after rotation of the latter, to be moved upwards and subsequently, after the tilting floor has been released from the concrete slab connected to it, to be moved downwards again whereafter the frame can be moved to a next section of the bed. In that case the tilting floor need not be arranged for upand-down movement.

Fig. 3 shows such a construction diagrammatically. A bed section 30 is shown in the raised position. For this purpose hydraulic jacks 31, 32 are present beneath each section, which in the embodiment shown are placed right under the sections, but may alternatively be disposed next to the bed sections and, for example, move the sections up and down through the intermediary of levers. Furthermore, Fig. 3 shows the tilting floor In the reverse position with the shafts 18 and 19.

The tilting floor rests on spacer members 11 placed on bed section 30. On bed section 30 lies a concrete slab 33, and a second concrete slab 34, retained on the tilting floor, is spaced from it a distance determined by the spacer members 11, with a lattice 35 being provided between the two slabs, which is partially embedded in the concrete of both slabs.

Starting from the situation shown, the tilting floor can now be released from slab 34, and bed section 33 can be moved back down again.

Subsequently the tilting floor can be turned back and the frame can be moved to a next bed section.

In order that the lattice or other spacer elements may properly penetrate the concrete of the lower slab of concrete, the bed section may be vibrated or jolted by means not shown. This can be brought about, for example, by means of a driven shaft with an eccentric thereon which cooperates with the bed section, or by hydraulic or pneumatic means.

Such a vibrating or jolting system may also be used to promote the release of the concrete slabs cast.

According to another modification of the invention, use can be made of a large number of tilting sections comparable with the tilting floor and supported some distance above the bed on supports placed alongside or on the bed, which supports may be either fixed or movable up and down. In that case, in fact, two superimposed beds are formed, of which the upper one consists of a plurality of loose tilting sections.

In that embodiment, concrete is poured on bed 2 and on the tilting sections placed above it, with a lattice being installed in the concrete on the tilting sections. When the concrete on the tilting sections has set, these are reversed.

Frame 3 should then be provided, instead of a tilting floor, with a device capable of being coupled with the loose tilting sections, so that a loose section can be engaged, moved upwards in the manner described, reversed after the concrete has set, and moved down again, whereafter the section is again disconnected. The frame can then be moved to a next bed section, where it can reverse a set concrete slab in a similar manner.

The device for reversing the loose sections with the cast concrete slabs on them may consist, for example, of a rectangular frame of steel bars capable of engaging around the edges of the section. Two opposed sides of the frame are then coupled with the shafts 1 8 and 1 9 and can be moved relatively to, or along with, the shafts in the longitudinal direction thereof. Furthermore locking means should be provided for locking the bars of the frame with the section and relatively to the frame so that the section can be reversed by motor 1 5. The bars of the two other sides of the frame are then also teiescopic, to be movable, for example, over terminal projections of the first two bars and lockable therewith, for example, by means of bolts or wedges.It is even conceivable to have two bars coupled with the shafts only.

It is also possible for the sections to be provided at their bottom or at their longitudinal sides with lugs through which beams can be inserted which, by means of cross-connectors, can be connected to shafts 1 8, 19.

In order to retain a concrete slab on a tilting floor or tiltable section, use can be made, in a suitable manner, of a vacuum system which sucks the concrete slab against the tilting floor or section.

Finally it is possible for the tilting floor or the loose tilting section to be designed and arranged in such a manner that a concrete slab can be formed on both the upper and the lower face thereof. This will restrict the number of requisite reversions of the tilting floor or sections, while when loose sections are used time can be saved by virtue of the fact that immediately after the reversal of a plate a next slab of concrete can be cast on the side which is then the top surface.

It is noted that there are a large number of structural possibilities for realizing the constructions proposed hereinbefore in practice.

Such possibilities are within the reach of those skilled in the art and are considered to fall within the scope of the present invention.

It is further noted that the method described is also suitable for the manufacture of other hollow concrete elements comprising at least two spaced parallel concrete slabs.

Finally it is noted that the tilting floor or the tilting sections, as described hereinbefore, can be used with advantage for lifting the ready hollow elements, after these have set to a sufficient extent, and for tilting them, if necessary, for the ready elements to be subsequently transported to a storage site by means of a crane or the like.

Claims (20)

1. A method of making hollow elements from concrete, which comprises making a first concrete slab and a second concrete slab and placing one upon the other with spacer elements between them, wherein the concrete slabs are formed on casting surfaces, the first slab being provided with spacer elements and, after being sufficiently set, being turned over above the mortar bed of the second slab, whereafter the vertical distance between the two siabs is reduced to such an extent that the said spacer elements force themselves partially into the concrete of the second slab, which at the moment is still sufficiently soft, in which position, after compaction of the second slab, the composite element is allowed to set further.

2. A method according to claim 1, wherein the casting surfaces are located next to each other.

3. A method according to claim 1, wherein the casting surfaces are located one above the other.

4. A method according to any of claims 1 to 3, wherein the distance between the two slabs is reduced by moving the upper slab downwardly after reversal thereof.

5. A method according to any one of claims 1 to 4, wherein during the reduction of the distance between the two slabs, the lower slab is moved upwardly.

6. A method according to ciaim 3 or claims 4 or 5 as dependent on claim 3, wherein the slabs are cast on two beds located one above the other, at least the upper one of the said beds comprising a plurality of loose tiltable sections which, after sufficient setting of the concrete cast thereon, are successively reversed.

7. A method substantially as herein described with reference to the accompanying drawings.

8. Apparatus for carrying out the method according to claim 1, comprising a casting surface on which at least one concrete slab of the required dimensions can be cast, and a tilting floor positioned above the said casting surface, on which tilting floor at least one second concrete slab of the required dimensions can be laid and retained, and which floor is mounted for up-anddown movement and for rotation about one of its horizontal axis in a frame placed over the lower casting surface, the said frame including means for moving the tilting floor upwardly and downwardly and for rotating it.

9. Apparatus according to claim 8, wherein the said casting surface forms part of an elongated bed comprising a plurality of casting surfaces, and that the said frame includes wheels capable of travelling over travelling surfaces provided on opposite sides of the said bed.

10. Apparatus according to claims 8 or 9, wherein the frame extends over a second casting surface for forming the second concrete slab, located next to the first casting surface, and includes a mobile lifting device capable of lifting the second concrete slab and placing it on said tilting floor.

11. Apparatus according to claim 9 or 10, wherein each of said plurality of casting surfaces is movable upwardly and downwardly by means of a suitable lifting device.

12. An apparatus according to any one of claims 9 to 11, wherein adjustable spacer members are provided at least adjacent to the corners of each of said plurality of casting surfaces, on which spacer members the tilting floor can come to rest after rotation.

1 3. Apparatus according to any of claims 9 to 12, wherein the said frame comprises two opposed central uprightsjournalling two aligned stub shafts, extending towards each other, for upand-down movement and rotary movement, the stub shafts being arranged to carry the upper casting surface, and at least one of the shafts being coupled to a rotating device capable of rotating the stub shaft, and both stub shafts being coupled with synchronized drive means for moving the stub shafts up and down along the said uprights.

14. Apparatus according to any of claims 9 to 13, for carrying out the method according to claim 6, wherein a loose section serving as an upper casting surface is placed on suitable supports above each lower casting surface, and that the said frame includes means for engaging a loose section on which a concrete slab is retained, moving the same upwards, turning it, moving it downwards, and releasing it again.

1 5. Apparatus according to claim 14, wherein the means for engaging a loose section comprise at least two steel bars extending horizontally and transversely to the stub shafts and coupled therewith so as to be slidable over some distance in the longitudinal direction of the stub shafts, the said bars being shaped to be capable of engaging around the corresponding edges of the loose section, and being lockable in that position.

16. Apparatus according to claim 15, wherein each end of a steel bar is coupled by means of a similar third and a simiiar fourth steel bar, respectively, to the corresponding end of the opposite steel bar, the said third and fourth steel bars being coupled with the first two steel bars in such a manner that they can be brought into, and out of, engagement with the loose section, and capable of being locked at least in the position in which they are in engagement with the loose section.

1 7. Apparatus according to claim 14, wherein each loose section is provided with lugs located outside the said casting surface, and in which beams can be arranged which can be fixedly coupled with the stub shafts.

1 8. Apparatus according to any of claims 8 to 1 7, wherein the tilting floor or the loose sections are provided with a vacuum device for retaining a concrete slab during the tilting thereof.

19. Apparatus according to any one of claims 9 to 18, wherein each section forming an upper casting surface is so designed that both its upper surface and its lower surface can be used for casting a concrete slab thereon.

20. Apparatus for making hollow elements from concrete substantially as herein described with reference to the accompanying drawings.