AU670933B2 - Formwork device - Google Patents

Description

Our Ref: 464527 P/00/011 Regulation 3:2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT 00 0 o o 0 o 00 00 o0 0 00 0 00 0 o m o o o 0 o e ao o oo0 o o oo 0*00 on 0 09 Applicant(s): Collimore 22 Doolan DEAN PARK

AUSTRALIA

Enterprises Pty Ltd Street NSW 2761 Address for Service: Invention Title: DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 Formwork device The following statement is a full description best method of performing it known to me:of this invention, including the 5020 0056q/DYS FORMWORK DEVICE This invention relates to structures which may be formed from concrete or other materials which are initially in a flowable state and subsequently harden to form the structure. The structures may be in the form of slabs suitable for use in building foundations, road paving or the like. More particularly the invention relates to a method and/or apparatus or devices suitable for use in the formation of such structures.

Australian patent specification no. 584,709 describes a o method of forming a building foundation wherein a series of hollow box-like members are disposed in a selected 00 0configuration over ground upon which a concrete foundation S is to be positioned. The box-like members are positioned relative to one another using spacer bricks. The spacer So bricks have grooves therein for locating reinforcing rods in 0 position. The spaces between the box-like members form a network of channels which, following pouring of the 0 concrete, define a series of concrete beams and slab structure.

0 0 The above method suffers from the disadvantage that the a o a 0 0 positioning of the box-like members relative to one another utilizing the spacer bricks is a very time consuming procedure. Another problem concerns the size of the box-like members which may not be dimensioned to facilitate the ready formation of slabs of different sizes.

It is therefore an object of the present invention to provide an improved formwork device for use in the formation of structures of the type referred to above which alleviates one or more of the aforementioned disadvantages. It is also an object of the present invention to provide an improved method of forming such structures.

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P:\WPDOCS\DYS\SPECIE\COLLIM.CLA 17/6/96 -2- According to one aspect of the present invention there is provided a ground slab formwork device for use in the formation of concrete slabs, the device including a main body including a side wall and top wall and a laterally extending flange projecting from a lower edge of the side wall such that when two such devices are disposed in adjacent but spaced apart relation relative to one another, the flange forms a spacer element so that the two devices can be disposed in selected spaced apart relation to one another and forms a barrier between the ground upon which the slab is to be laid and the space between the adjacent devices, and an upstanding element projects upwardly from said flange forming a platform for supporting reinforcing elements.

According to another aspect of the present invention there is provided a method of o a: forming a concrete slab using a plurality of devices, as described above the method including the steps of arranging the devices or the devices and separated portions thereof in a selected array on the ground upon which the slab is to be disposed so that the spaces therebetween form channels, pouring concrete over the array so that the spaces between the devices are a 2 filled with material and the devices are covered by the material, the arrangement being such S: that when the material hardens, the material within the spaces will define a network of beams a which form part of a slab or like structure.

S° ~a I 0056q/DYS 3 -bweent-he-deviraz-are filled with material and th! are covered by the material. When th a hardens, the material withinhe es will define a network of beams or-rm part of a slab or like structure.

In use, a plurality of formwork devices according to the invention are arranged in a preselected array over ground upon which the structure is to be formed. The spacer element associated with each device is adapted to enable adjacent devices to be disposed relative to one another with spaced therebetween. In use the spacer element on one device is brought into abutment with a part of an adjacent device. These spaces between adjacent devices are arranged o° so that when filled with concrete or like material they will form a network of beams for the structure being formed.

ooc 00 0 The main body of the device may be in the form of a 0 hollow member having an open bottom side. Preferably the 0 0 hollow member is box-shaped and the side wall comprises four side wall sections generally at right angles to one another. In use, the free edge of the side wall is adapted to rest on the ground.

The spacer member may comprise projections which extend from the side wall or respective sections of the side wall.

In one form the spacer members may comprise a laterally 00. extending flange section projecting from the side wall of the main body. Preferably the flange section extends generally at approximately right angles to the plane containing the side wall. In addition the spacer member may include an upstanding portion projecting upwardly from the laterally extending flange section. In one preferred embodiment, the spacer member is disposed at or near the free end portion of the side wall. The laterally extending section of the spacer member may extend continuously around the side wall of the main body.

Advantageously the side wall sections of the main body

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1 are inclined slightly inwardly from the free end portions f i l j t__ 0056q/DYS 4 thereof in the direction towards the top wall. This enables the devices to be able to nest within each other to facilitate ease in transport. Furthermore the space between two adjacent devices when in use has inclined sides so that the beam so formed has increased strength.

The device may further include supports which in use support reinforcing members which are used in the formation of the structure. The reinforcing members may be in the form of bars or rods which are arranged in a selected network. The supports may be in the form of platforms upon which the reinforcing members can rest. In one arrangement the platforms may be defined by upstanding flanges extending from the laterally extending section of the spacer member.

o Preferably the support flanges are disposed at each corner of the box-shaped main body and may, for example, be o a L-shaped with one arm extending along one side wall section a o and the other arm extending along an adjacent side wall section. It will be appreciated that the spacer member and the supports may be comprised by the same flanges.

Locating elements may be provided for correctly positioning the reinforcing elements on the supports and O.O inhibiting undue lateral movement thereof. The locating elements may be in the form of one or more upstanding posts or spigots projecting upwardly from the spacer flange.

oo a QQ o a a The device may further include one or more load supporting members which project from or extend between the top wall and the free edge portion of the side wall. The load supporting members may comprise columns which may be generally frusto-conical projections extending from the top wall. Preferably these projections may be hollow and may include a removable cap section for closing the opening in the top wall. By this arrangement, the devices can be still nested together for transportation purposes.

The separation zones preferably comprise guide lines of weakness in the wall or walls of the main body along which 0056q/DYS the main body can be more readily cut. The separation zones may comprise perforated portions, grooves or the like formed on the wall surface of the main body. Preferably a plurality of such zones are provided in the walls of the main body at selected positions on the outer surface thereof.

The various aspects of the invention described above may be used separately or more advantageously in combination. The device may be formed from any suitable materials using any suitable manufacturing technique.

Preferably the device including all of its integers in any of its preferred forms is formed as an integral unit. The device is advantageously made of plastics material such as, ooo for example, polypropylene. Any suitable plastics moulding 0.0 technique may be used.

By the arrangement of a barrier between the ground and 00 a the space it is believed that moisture in the ground will be o inhibited from penetrating the concrete or like material disposed within the space.

0. Preferred embodiments of the invention will hereinafter be described with reference to the accompanying drawings, in oo 00 o awhich: "Figure 1 is a schematic perspective view of a formwork device according to the invention; and °Figure 2 is a schematic view showing two formwork devices arranged in operative position relative to one another.

Referring to the drawings, there is shown a formwork I device for use in the formation of a concrete slab. In i practice a series of such devices are used in the manner I which will hereinafter be described. The formwork device generally indicated at 1 comprises a main body 2 in the form of a hollow box-like member having a top wall 3 and a side wall 4, the side wall 4 comprising four sections 4A, 4B, 4C and 4D. The lower edge 5 of the side wall 4 is arranged, when in use, to rest on the ground upon which the concrete

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i m I J i II II I I 0056q/DYS -6slab is to be laid.

The device further includes a spacer element 10 which in part is in the form of a continuous flange 11 which extends laterally from the side wall 4 adjacent the free edge 5 thereof. As best appreciated from figure 2, when two devices are arranged side by side, flanges 11 are in abutting relation and thereby form a barrier between the ground and the space 55 between them. With such an arrangement, it may be possible to dispense with the membrane normally required to cover the ground where a slab is to be laid to prevent moisture from seeping into the concrete.

osr There is further provided a plurality of reinforcing supports 15 in the form of L-shaped upstanding flanges 16 disposed at the corners between the side wall section s of aside wall 4. These support flanges which can also act as the spacer elements are arranged to carry thereon reinforcing bars or rods 50 at a selected height above the Sground. Locating elements 20 in the form of posts or a spiggots 21 are arranged to limit lateral movement of the a a reinforcing bars prior to the concrete being poured.

oa, The main body 2 of the device further includes load supporting members 25 which, in the form shown, are a generally frusto-conical column-like elements which project 0 from the under-surface of the top wall and terminate in the region of a plane containing the lower edge 5 of the side wall 4. The load supporting members 25 are hollow and have openings 27 in the top wall which are arranged to be closed by means of caps 28. Ribs 29 may be provided on the outer surface of the columns in order to assist in separation of devices when in a stacked nested condition.

The main body 2 further has a series of lines of weakness 30 formed in the surface of the top and side walls thereof to facilitate ready separation of the main body along those lines of weakness.

0056q/DYS -7- When used in the formation of a foundation or slab the formwork devices are placed side by side in a selected array on the ground upon which the foundation or slab is to be laid. It will be appreciated that by bringing the spacer flanges 11 of adjacent devices into contact with one another a network of spaces can be formed between the devices which after the concrete is poured will form a network of concrete beams.

If necessary, some of the devices can be broken along selected lines of weakness 30 to ensure that the devices suit the desired final configuration of the foundation.

000 It will be seen that adjacent flanges 11 form a barrier 0 between the ground and the concrete beam subsequently formed. Once the devices are located in the desired oo o configuration relative to one another the reinforcing rods are positioned so that they rest on upstanding flanges 16 and one retained in position by posts 21.

The concrete is then poured over the devices and flows into the spaces to form a network of beams which make up at S0 least in part the concrete slab.

Finally it is to be understood that various 0 0 alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit and ambit of the invention.

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Claims (11)

1. A ground slab formwork device for use in the formation of concrete slabs, the device including a main body including a side wall and top wall and a laterally extending flange projecting from a lower edge of the side wall such that when two such devices are disposed in adjacent but spaced apart relation relative to one another, the flange forms a spacer element so that the two devices can be disposed in selected spaced apart relation to one another and forms a barrier between the ground upon which the slab is to be laid and the space between the adjacent devices, and an upstanding element projects upwardly from said flange forming a platform for supporting reinforcing elements.

2. A formwork device according to claim 1 wherein said main body has separation zones disposed in selected regions thereof whereby the main body can be separated into sections of preselected size, the separation zones comprising guide lines of weakness in the wall or walls of the main body along which the main body can be more readily cut. a

3. A device according to claim 1 wherein said main body comprises a generally box shaped hollow member having an open bottom side, the side wall comprising four side wall o: sections generally at right angles to one another, with the free edge of the side wall being t oo te 0 o adapted to rest on the ground when in use. 20

4. A device according to claim 1, 2 or 3 wherein the flange extends continuously around 0 0 the side wall of the main body.

A device according to any preceding claim wherein the side wall sections of the main body are inclined slightly inwardly from the free end portions thereof in the direction towards iI the top wall.

6. A device according to any preceding claim wherein the support flanges are disposed at each corner of the box-shaped main body and are L-shaped with one arm extending along one side wall section and the other arm extending along an adjacent side wall section. r i P:\WPDOCS\DYS\SPECIE\COLLIM.CLA. 17/6/96 -9-

7. A device according to any preceding claim further including locating elements for correctly positioning the reinforcing elements on the supports and inhibiting undue lateral movement thereof, the locating elements including one or more upstanding posts or spigots projecting upwardly from the flange.

8. A device .ccording to any preceding claim further including one or more load supporting members which project from or extend between the top wall and the free edge portion of the side wall, the load supporting members comprising columns which comprise generally frusto-conical projections extending from the top wall, and include a removable cap section for closing the opening in the top wall. 0 044

9. A device according to any one of claims 2 to 8 wherein separation zones comprise 0 00 perforated portions, grooves or the like formed on the wall surface of the main body, there being a plurality of such zones are provided in the walls of the main body at selected positions on the outer surface thereof.

10. A method of forming a concrete slab using a plurality of devices according to any i preceding claim the method including the steps of arranging the devices or the devices and separated portions thereof in a selected array on the ground upon which the slab is to be S 20 disposed so that the spaces therebetween form channels, pouring the concrete over the array so that the spaces between the devices are filled with material and the devices are covered by the material, the arrangement being such when the material hardens, the material within the spaces will define a network of beams which form part of a slab or like structure.

11. A formwork device substantially as hereinbefore described with reference to the accompanying drawings. Dated this 17th day of June, 1996. COLLIMORE ENTERPRISES PTY LTD By Its Patent Attorneys DAVIES COLLISON CAVE i M 0056q/DYS ABSTRACT A formwork device suitable for use in the formation of structures suc)h as concrete slabs, which comprises a main body having a sida wall, an upper wall and at least one spacer element projecting from the side wall such that when in use, the spacer element on one device can be arranged to engage a section of an adjacent device so that the two devices can be disposed in selected spaced apart relation to one another. The me body may include lines of weakness in the wall or walls thereof along which the main body can be more readily cut. A laterally extending flange may project from a lower edge of the main body such that when two such devices are disposed in adjacent but spaced apart o relation relative to one another, the flange forms a barrier between the ground and the space between the adjacent devices. 0 4 04 o o o o