AU4583902A - Form work device - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant: PAUL MICHAEL DOHERTY Invention Title: FORM WORK DEVICE The following statement is a full description of this invention, including the best method of performing it known to us: 2 FORMWORK ARRANGEMENT The present invention relates generally to civil engineering constructions and structures and particularly to methods and apparatus for forming such structures, particularly forming the structures in situ. More particularly, the present invention relates to a method and device for forming a structure in situ using an adjustable formwork arrangement which is changeable to take into account that the structure that can have a number of different shapes or configurations. Even more particularly, the present invention relates to a formwork arrangement and method of using the formwork to form a structure, such as for example, an inspection pit, junction block or similar in drainage, sewerage or similar systems, particularly involving the flow of water and joining of two or more different conduits together. Even more particularly, the present invention finds particular application as a universal formwork arrangement for use in forming in situ an inspection pit which formwork arrangement can accommodate a variety of different shapes or configurations of the inspection pit irrespective of the number of pipes leading into and from the inspection pit and/or the number of different directions along which the pipes are aligned.

Although the present invention will be described with particular reference to one form of the formwork arrangement, jig, device or similar and to a method of using the formwork arrangement, etc., it is to be noted that the scope of the present invention is not restricted to the described embodiment but rather the scope of the present invention is more extensive so as to include other arrangements and devices for forming the structures and other methods of using such devices and arrangements in applications other than that specifically described.

When forming drainage systems or sewerage systems or similar systems involving the flow of water through \\melbfiles\homeS\PClarke\Keep\specis\Formwork Arrangement Doherty.doc 6/06/02 3 pipes, it is necessary to provide inspection pits or junction boxes or blocks, or similar at spaced apart intervals along the pipeline in order to provide access to the pipeline for various purposes, such as for example, cleaning of the pipes. The inspection pits or the like are usually made from concrete. Inspection pits or junctions are provided where two or more pipes join together either collinearly or at an angle to each other.

In some instances, the inspection pit merely provides access at a selected location to a straight pipe and accordingly only two oppositely facing collinearly arranged pipes are joined together. However, in other situations three or more pipes extending at different angles to each other are to be joined together at the same junction, such as for example, two pipes being arranged collinearly with a third being arranged substantially perpendicularly to the other two. However, the third pipe may extend at any angle from the other two. In still further situations, four or more pipes may be joined together at a range of different angles to one another.

At still other locations it may be necessary to join two pipes together at an angle to each other, such as perpendicularly, when the pipeline is to turn a corner or divert from the straight ahead direction. Thus, there are many different and varied shapes and configurations for inspection pits or the like depending on circumstances.

In the past it was necessary to form the structure for the junction of the pipes or the inspection pit in situ by custom framing the formwork to suit the particular requirements of the location and situation.

The formwork was typically made from timber which after having been cut and shaped to the exact dimensions of the particular inspection pit was discarded as it was only in exceptional circumstances that the formwork itself or the timber from which it was made could be reused. Thus, the formwork was expensive to make. Moreover, it was time consuming to custom make the wooden formwork in situ for \\melb-files\homeS\PClarke\Keep\specis\Forork Arrangement Dohertydoc 6/06/02 4 each individual inspection pit, particularly since the formwork could not be reused or would not be suitable for forming another inspection pit at a different location.

Further, as the inspection pit or junction was located beneath the surface of the ground it was necessary to excavate a pit or similar excavation in which to construct the inspection pit structure to form the wooden frame work. The dimensions of the excavation had to be greater than the dimensions of the inspection pit or similar as work men needed to be able to be located in the space between the outer wall of the wooden framework and the inner wall of the excavation in which to be able to work to form the wooden frame work for forming the walls of the structure. This necessitated the excavation being considerably larger than the inspection pit since the formwork needed to be made sufficiently strong enough to be able to support wet concrete after it had been poured into the formwork to form the structure but before it cured into the final shape of the inspection pit or other structure. All of these circumstances conspired to make the formation of a structure such as an inspection pit time consuming, and expensive both of labour and materials. Thus, there is a need to reduce the time, effort and expense of forming structures such as inspection pits.

Therefore, it is an aim of the present invention to provide a method and apparatus including the use of an almost universal formwork arrangement for forming a concrete inspection pit or similar structure irrespective of the particular requirements of the individual structure so that the formwork arrangement can be used to quickly and easily form the inspection pit or similar which formwork arrangement is adjustable by being sufficiently flexible to accommodate different arrangements of pipes leading into and from the inspection pit when forming the inspection pit. Additionally, use of the formwork reduced the number of workmen needed on site to complete the \\melbfiles\home$\PClarke\Keep\specis\Formwork Arrangement Doherty.doc 6/06/02 5 structure.

According to one aspect of the present invention, there is provided: a formwork arrangement, jig, device or similar for forming a wall of a structure having a fitting or similar extending at least partially from or through the wall including a first wall forming member extending from a level or position corresponding to a first base line or base level of the wall of the structure being formed to a level near to or corresponding to the top of the wall of the structure being formed; and a second wall forming member extending from a level or position corresponding to a second base line or level of the wall of the structure being formed to a level near to or corresponding to the top of the wall of the structure being formed, said first and second wall forming members being spaced apart from each other for forming the wall of the structure therebetween and the first base line or level and the second base line or level being spaced apart from each other such that the space between the two levels associated with the second wall member is open wherein the second wall member is provided with an adjustable cover means for covering the open space in use of the formwork arrangement such that the position of the cover means is adjustable to accommodate the fitting when located in or through the open space to substantially cover or close the open space thereby allowing the wall of the structure to be formed between the two wall members from the first base line or level to a level associated with the top of the structure.

According to another aspect of the present invention there is provided a method of forming a wall of a structure having a fitting extending therefrom or passing through the wall including the steps of: forming a base for the structure; locating a formwork arrangement on the base of the structure, wherein the formwork arrangement includes: \\melbf iles\home$\PClarke\Keep\specis \Fmor rk Arrangement Doherty.doc 6/06/02 6 a first wall forming member extending from a level or position corresponding to the level of the base of the structure to a level near to or corresponding to the top of the structure being formed and a second wall forming member extending from a level or position located above the base of the structure to a level near to or corresponding to the top of the wall, said first and second wall members being spaced apart from each other for forming the wall of the structure therebetween and the space between the base of the structure and the lower part of the second wall member located above the base of the structure being open; positioning the fitting on the base adjacent the first wall member of the frame work arrangement to extend below the second wall member through the open space; adjusting the position of an adjustable cover means for covering or closing the open space between the base of the structure and the lower level of the second wall member to substantially cover or close the open space; introducing material from which the structure is being made into the gap between the first and second wall members; allowing the material to stand for a predetermined time to allow the material to attain structural integrity or be self supporting; removing at least a part of the formwork arrangement from the wall of the structure, thereby forming the wall of the structure.

Typically, the structure is made from concrete.

More typically, the concrete structure is prepared in situ. Even more typically, the concrete structure is formed in an excavation pit or similar.

Typically, the structure is an inspection pit, junction box, block or similar. More typically, the structure is the inspection pit of a drainage or sewerage system. Even more typically, the structure is \\melb.files\homeS\PClarke\Keep\specis\Formork Arrangement Doherty.doc 6/06/02 7 substantially rectilinear having four walls arranged to extend substantially perpendicularly to each other. Even more typically, the structure has one, two, three, four or more levels at, towards or associated with the base. Even more typically, the structure has a dual level base.

Typically, the structure can take any form, shape or size. The structure can be used for a variety of purposes, such as for example, water, drainage, sewerage, a cable junction box, or access pit or box for electricity cables, telephone cables, or other. Typically, the structure can be made above the ground or below the ground and be of any size.

Typically, the first wall member of the formwork is one of a plurality of similar wall members. More typically, there are four first wall members. Even more typically, the four wall members are joined to each other to form the inner wall of the formwork arrangement.

Typically, the second wall member is spaced apart from the first wall member to the thickness of the wall. More typically, there are four second wall members joined together. Even more typically, the four second wall members extend substantially perpendicularly to each other. Even more typically, the second wall members form the outer wall of the formwork arrangement.

Typically, the formwork is provided with adjustable legs. More typically, the adjustable legs are located at or towards the base or bottom end of the formwork. Even more typically, the adjustable legs rest upon the base of the structure, particularly a base having more than a single level.

Typically, the adjustable legs are provided with feet. The adjustable feet are for forming the base of the structure. More typically, the adjustable legs are located along the sides of the formwork or at the corners of the formwork. Even more typically, the adjustable legs and/or feet are associated with the outer wall member or members of the formwork.

\\melbfies\homeS\PClarke\Keep\specis\For ork Arrangement Doherty.doc 6/06/02 8 Typically, the adjustable legs and/or feet are for forming rebates in the base of the structure or in the structure itself.

Typically, the formwork is provided with height adjustment means. More typically, the height adjustment means is a jack, particularly a screw jack. More typically, there is a screw jack located at each corner of the formwork. Even more typically, the screw jacks are for adjusting the height of the formwork.

Typically, each jack is located at the corners of the outer wall member. More typically, each jack is associated with an adjustable corner post located at or towards each corner. More typically, movement of the jack causes the adjustable corner post to move.

Even more typically, the adjustable corner post is provided with an internally threaded sleeve for receiving an externally threaded shaft therein.

Typically, rotational movement of the shaft in the sleeve moves the sleeve longitudinally to adjust the height of the corner post to accommodate the differences in the height of uneven ground upon which the form work rests.

Optionally, each corner post is provided with a foot portion or similar for contacting the ground.

Typically, the fitting is a pipe, conduit, cable or similar. Typically, there are two, three, four or more fittings provided in the walls of the inspection pit.

More typically, there is a single pipe associated with one or more of selected wall sections or with all wall sections by the pipe extending from the wall section or sections. More typically, the pipes extend perpendicularly from the walls. Typically, the pipes extend angularly from the walls. Typically, more than a single pipe extends from the wall section or sections.

Typically, the cover means is adjustable in both length and width. More typically, the cover means includes a plurality of adjustable cover elements. More typically, each of the plurality of adjustable cover \\melbfiles\homeS\Clarke\Keep\specis\Formork Arrangement Doherty.doc 6/06/02 9 elements is individually adjustable. Typically, the elements include elongate elements extending lengthwise from towards the base of the structure towards an intermediate location between the base and top of the formwork arrangement. More typically, the cover means includes a plurality of lengths of timber, metal or the like. Even more typically, the lengths of timber are adjustable around the periphery of the fitting, pipe or similar to close or cover the open space so as to substantially retain concrete when wet in the space or gap between the inner wall and the outer wall. Even more typically, the elements are provided with retaining means for retaining the elements in selected desired positions during use of the formwork. Typically, the retaining means are bolts, pins, clips, fasteners clamps or the like.

The present invention will now be described by way of non-limiting example with reference to the accompanying drawings in which: Figure 1 is a top plan view of one embodiment of the formwork arrangement of the present invention.

Figure 2 is a side view of the embodiment of Figure 1 taken along the line 2-2 of Figure i.

Figure 3 is a cross-sectional view taken along the line 3-3 of Figure 1 when the formwork arrangement is in its normal in use position.

Figure 4 is a partial cross-sectional view similar to Figure 3 but showing the formwork arrangement in a position just at the commencement of lifting from the walls of the structure being formed by the formwork.

Figure 5 is a partial cross-sectional view similar to Figure 4 but showing the formwork arrangement being lifted from the structure.

Figure 6 is a top perspective view of one corner of the formwork arrangement showing the channel members for retaining the cover means in more detail.

Figure 7 is an internal view of one side of the \\melb files\homeS\PClarke\Keep\specis\Formwork Arrangement Doherty.doc 6/06/02 10 formwork arrangement.

In the drawings, there is shown one embodiment of the formwork arrangement of the present invention, which is generally denoted as 2. Formwork 2 is located on a prepared concrete base that has been poured previously in the excavation in which the inspection pit is to be formed and allowed to cure solid before formwork 2 is positioned on it. The concrete base of the structure is denoted by reference numeral 3 in the drawings. Concrete base 3 can take any suitable form or shape. In the embodiment shown in the drawings the level of base 3 is uniform which is to say the upper surface of the base is all at the same level. However, in other embodiments not shown, the level may be non-uniform, such as for example, being stepped, having a rebate, or having two or more surfaces at different levels.

Formwork 2 comprises an inner wall arrangement 4 made up of four separate wall members 6a, 6b, 6c and 6d, perpendicularly arranged with each other to form the inner wall 4 in a box like structure. Panels 6a, 6b, 6c and 6d extend from towards the bottom or lower end or edge of arrangement 2 to a level near to or corresponding to the top of the arrangement as shown particularly in Figures 3 and 5. It is to be noted that panels 6a to 6d do not extend as far down as to the lower level of base 3 as is shown more particularly in Figure 3 in which the collective lower edges of inner wall 4 rest upon the upper surface of base 3 as indicated at point 7 in Figure 3.

Although, the embodiment illustrated in the drawings shows that the upper level or surface of base 3 is at the same level and accordingly the lower edges of panels 6 are all at the same levels resting upon the upper surface of base 3, it is to be noted that the different panels 6 may be located at different heights to each other or at different combinations of heights depending on the specific arrangement of base 3.

A substantially upright solid post 8 is located \\melbfiles\homeS\PCarke\Kteep\specis\Formwork Arrangement Dohertydoc 6/06/02 11 at the edge of each panel 6 so that there are four solid posts 8, one located at each corner of inner wall 4. A lifting bracket or similar 10 is located at or towards the top of each upright post 8. A support (not shown) is located at the lower end in use of each post 8. One or more pipes 12 which are located upon the upper surface of base 3 extend perpendicularly from inner side wall 4, such as for example, pipe 12a extends from side 6d and pipe 12b extends from side 6c. Inner wall 4 extends from at or towards the top of the structure being formed such as is indicated at point 5 of figure 3 to the base 3 of the structure at point 7 where the lower edges of wall 4 rests upon base 3 as shown more particularly in Figure 3.

Formwork arrangement 2 further includes an outer wall arrangement generally denoted as 20. Outer wall arrangement 20 has four substantially perpendicular side sections or panels 22a, 22b, 22c and 22d arranged around the outside of inner wall 4 such that outer wall panel or section 22a is spaced apart from inner wall panel or section 6a; outer wall section 22b is spaced apart from inner wall section 6b; outer wall section 22c is spaced apart from inner wall section 6c; and outer wall section 22d is spaced apart from inner wall section 6d. The gap or spacing 25 between the corresponding outer wall panels 22 and inner wall panels 6 is the thickness of the wall 24 of the structure which is formed by pouring wet concrete into the space or gap 26 between the inner wall 4 and outer wall 20. Four substantially L-shaped section upright posts 28 are provided at the four corners of outer wall With particular reference to Figure 3, outer wall extends from a position at or towards the top of the structure as indicated by point 25 to a position above the base 3 of the structure, as indicated by point 27 so that the fitting typically in the form of pipe 12b, can be located adjacent the outer surface of inner wall 4 underneath the lower edge of outer wall 20 so as to extend \\melb- f files\home$\PClarke\Keep\specis\Form.ork Arrangement Dohertydoc 6/06/02 12 perpendicularly from the structure. Inner wall 4 is formed from plate steel panels 6a,6b,6c,6d welded together so as to form the generally rectilinear inner box arrangement and outer wall 20 is also formed from plate steel panels 22a,22b,22c,22d welded together so as to form the generally rectilinear outer box arrangement.

A bracket arrangement 30 is formed at or towards the respective tops of each external corner of inner wall 4 and internal corner of outer wall 20 for connecting outer wall 20 to inner wall 4. Thus, in one embodiment there are four such bracket arrangements 30. In one form bracket arrangement 30 includes four inwardly directed bracket plates 32a, 32b, 32c and 32d having their respective outer edges welded to the respective internal corners of two adjacent panels forming the outer wall A hollow elongate sleeve 34 is welded to the inboard end of bracket plate 32. The top of post 8 is received in sleeve 34 such that the inner and outer walls are slidably moveable with respect to each other in the lengthwise extending direction of posts 8 in use of formwork 2.

Inner wall 4 and outer wall 20 can adopt a number of different positions with respect to each other during lifting of formwork 2 as will be described later in this specification. A collar 36 is fixedly connected to each post 8 at a position below the lower end of sleeve 34 so that in use of formwork 2 when the inner wall is lifted by means of lifting bracket 10 collar 36 contacts sleeve 34 to also raise outer wall 20 which will be described in more detail later in this specification.

Other embodiments of formwork 2 (not shown) are provided with screw jacks located at each corner of outer wall 20 at or towards the top of outer wall 20. In one form the screw jacks have an upper end provided with a hexagonal nut or hexagonal shaft which is adapted to cooperate with a handle or other operating means so that as the handle is operated the shaft is turned. The upper end of the screw jack, which is circular, is held captive \\.elbfiles\homeS\pClarke\Keep\specis\Formork Arrangement Dohertydoc 6/06/02 13 in an upper rail provided around the top of the form work.

The shaft of the screw jack extends between the upper rail and an intermediate rail. The lower end of the shaft is externally threaded and is threadingly received in an internally threaded adjustably positionable tube or sleeve which extends longitudinally along the corner of the form work and is movable with respect to the form work. The adjustably positionable tube is provided with a lower end which in use contacts the ground upon which the form work rests. The lower end is provided with a suitable foot or foot portion. In operation when the handle 6 is rotated the shaft rotates accordingly. As the shaft is held in position with respect to the form work, as the shaft rotates the tube or sleeve is raised or lowered depending upon the direction of rotation of the shaft to lower or raise the height of the form work. In this manner the form work can be stably located on the ground irrespective of how uneven the ground surface is.

Other embodiments include adjustable legs and feet located at one or more spaced apart locations along one or more of wall panels 22a,22b,22c,22d. The adjustable legs and feet are for use in accommodating the unequal upper surfaces of base 3 or the rebates formed in the upper surface of base 3. One form of the adjustable leg includes an elongate rod extending along the inner side surface of one of side panels 22a,22b,22c,22d. One form of the feet attached to the end of the elongate rod is in the form of a right angled bracket or flange in which the upright of the IL' is connected to the elongate rod and horizontal part of the L-shaped bracket contacts the upper surface of base 3. The elongate rod is attached to the inner wall of the side panel by a suitable bracket in the form of a collar and suitable fastener, such as a treated pin having a T-shaped handle or similar.

With particular reference to Figure 2, one side of formwork 2 will now be described in detail. An upper elongate substantially horizontal transverse rail 40 is \\melbpfiles\home$\PClarke\Keep\specis\Forork Arrangement Doherty.doc 6/06/02 S14 secured to the outside surface of outer wall 20 such as by being fastened to corner posts 28 by welding or other suitable fastener, including bolt 42. Rail 40 is spaced apart from the outer surface of outer wall 20 by a plurality of generally rectilinear channels 44 formed by spacers 46 extending outwardly from wall 20 to rail A second lower elongate substantially horizontal transverse rail 50 extends along one side of the outer wall 20 at a level below upper rail 40. A plurality of channels 52 formed from spacers 54 are associated with this lower member. Typically, the channels 44, 52 are rectilinear in cross-section and are designed to receive respective ones of a plurality of elongate lengths of timber 48 in the aligned pairs of channels 44, 52 associated with the upper and lower transverse rails Each length of timber 48 is free to slideably move in the lengthwise extending direction whilst being restrained in channels 44, 52.

With particular reference to Figure 2, it can be seen that four of the lengths of timber 48 which are located towards the left hand side of the side of the outer wall 20 as viewed in Figure 2 rest upon base 3.

Also, the four lengths of timber 48 on the right hand side of this figure also rest on base 3. If necessary, the lengths of timber can rest on the bottom level or floor of the excavation in which the structure is being constructed. However, the four centrally located lengths 48 of timber shown in Figure 2 are in a substantially raised position by having their respective lower ends resting upon the upper surface in use of pipe 12 shown in Figure 2. It is to be noted that individual lengths of timber can adopt any vertical position in accordance with the profile at the lower surface of formwork 2 to take account of different sized pipes, different numbers of pipes and the different directions in which the pipes extend from the inspection pit, as well as the different base line levels of the ground or other structures that \\melbfiles\home\PClarke\Keep\specis\Formwork Arrangement Doherty.doc 6/06/02 15 may be nearby.

In one embodiment formwork 2 is provided with a suitable retaining means for retaining the cover elements in the form of lengths of timber 48 in the desired position. In one embodiment, the retaining means comprises a series of holes, apertures or bores 60 located at regularly spaced apart locations along the length of timber 48, for receiving a pin 62, bolt, shaft, clip, clamp or similar to retain the cover element at the selected height depending upon the position adopted by the particular length of timber.

In one embodiment, each adjustable cover element 48 is located in the raised position so that formwork 2 can be located in the excavation in the correct location with the lower edge of inner wall 4 resting on base 3 at point 7 either at the same level or at different levels.

When formwork 2 is in the correct position each of the adjustable cover elements 48 can be lowered so as to rest on either the base 3 or floor of the excavation or similar and pinned into position if necessary by retaining pin 62.

This allows the collective lower edges of the cover elements 48 to follow the contour of the base 3 or floor of the excavation or fitting 12 to seal the open space between the bottom edge of inner wall 4 and outer wall The cover elements located at the corner of the outer wall can take any desired suitable or convenient shape or configuration in conjunction with L-shaped posts 28. In one embodiment, two lengths of timber are arranged in an L-shaped relationship to extend around the outer corner of outer wall 20 whereas in another arrangement there is a single L-shaped length of timber surrounding the outer corner. Other arrangements are possible.

In Figures 1 and 6, an L-shaped metal post 28 is shown around the outer corner of the outer wall obviating the need to have any timber lengths in this region.

In operation of the device of the present invention, an excavation is formed at the location where \\melbfiles\home$\PCarke\Keep\specis\pormork Arrangement Dohertydoc 6/06/02 16it is desired to construct an inspection pit or similar for joining two or more pipes together to form the pipeline. The excavation is made of a size just larger than the dimensions of formwork 2 so that formwork 2 will fit comfortably inside the excavation. A concrete base 3 is formed on the floor of the excavation and allowed to cure until solid. Base 3 can be formed in a number of different configurations. In one embodiment, base 3 is formed with a spoon drain, culvert or similar substantially semi-circular cross-section channel or similar for each pipe extending into or from the inspection pit. If two pipes are to be joined a single channel extending between the open ends of both pipes is provided. If more than two pipes meet at the junction formed within the inspection pit each pipe is provided with its own channel and all of the channels intersect with each other at the centre of the base 3 to allow water flow from all inlet pipes to the outlet pipe. When base 3 has been formed and has attained sufficient strength to support the structure to be built on top of the base, the individual cover elements 48 are raised into their respective fully raised positions and retained in this position by the retaining pins 62 being received in the lowermost bore 60. The formwork 2 is then lowered into the excavation by means of a suitable hoist, crane or similar lifting device until it rests in position on base 3. Depending upon the number of pipes extending from the inspection pit, the pipes are positioned so that the in board directed open end of each pipe abuts against the outer surface of the lower part of inner wall 4 extending in the desired direction to mate with the remainder of the pipeline. Each individual covering element 48 is then released from its upper retained position by removing pin 62 from the lowermost bore 60 and lowered until the lower edge or end surface of each length contacts either base 3, the floor of the inspection pit or pipe 12 as illustrated in Figure 3. If necessary, each cover element is retained \\melb_files\homeS\PClarke\Keep\specis\Formork Arrangement Doherty.doc 6/06/02 17 in its respective lowered position by retaining pin 62 being received in one of bores 60 or by operation of whatever retaining means is used.

Concrete is poured into the gap 26 between inner wall 4 and outer wall 20 to form wall 24 therebetween.

The concrete is worked in the usual manner to remove voids and to compact the concrete according to accepted practices of building concrete structures. As the inner wall 4 reaches to base 3 at point 7 no concrete can escape through or past inner wall 4 internally into the inspection pit. Similarly, the spacing between individual adjacent cover elements 48 is insufficient for the concrete mixture to ooze or flow out past or around the cover elements. Therefore, the concrete is retained in the gap or space 26 between the inner 4 and outer walls A small amount of concrete can flow or ooze around pipe 12. However, in many cases this may be desirable to reinforce the join between pipe 12 and the inspection pit in the vicinity of the wall of the structure and to prevent the inspection pit leaking around the pipe.

The formwork is left to stand for a period of time to allow initial cure of the concrete.

After a predetermined time and while the concrete is still reasonably pliant or wet so as to provide some lubrication or slip between the concrete and the walls of the formwork, formwork 2 is lifted again by the use of a crane, hoist or similar connected to lifting brackets to raise formwork 2. Initially, raising lifting brackets connected to posts 8 raises the inner wall 4 slightly above the base level 3 at point 7 as shown in Figure 4 to form a gap 64 between them. By raising inner wall 4 only and maintaining outer wall 20 stationary less sheer or other disruptive forces are applied to the concrete wall so that inner wall 4 can slidingly move along the inner surface of the wall 24 of the structure without destroying the integrity of the wall. The sliding movement is assisted by slippage between the wall panel and the \\melb-f es\homeS\PCarke \Keep\specis\Formwork Arrangement Dohertydoc 6/06/02 18 concrete due to the wet state of the concrete. If'both inner and outer walls were initially lifted simultaneously there is a tendency for the wall 24 to be lifted off base 3 or for the wall to separate intermediate its upper and lower ends into two or more sections or to otherwise weaken the wall. Inner wall 4 is lifted until collar 36 contacts the lower end of sleeve 34 whereupon further upwards movement of wall 4 causes outer wall 20 to also rise due to the connection of the outer wall to the inner wall through bracket arrangement 30. Formwork 2 is continued to be raised as shown more particularly in Figure 5 to life outer wall 20 away from base 3 to form gap 66 as shown in Figure 5 whilst allowing the wall to remain in position connected to base 3. Thereafter, formwork 2 is further gradually lifted until formwork 2 is clear of the inspection pit structure.

The concrete structure is then allowed to fully cure and if further finishing of the structure is required, such as for example, if necessary forming a lid or top cover for the inspection pit or providing other fittings to the inspection pit, these operations can be done until the inspection pit is finished.

Advantages of the present invention are that use of the formwork of the present invention allows inspection pits or other similar concrete structures to be made more quickly, such as for example, two or three inspection pits can be made per day rather than the single pit which can be made presently using existing techniques. The formwork is adaptable for use in a variety of situations requiring different shaped concrete structures or the like. The concrete structures can be made using less man power since one or two workmen can satisfactorily perform all operations necessary to form the structure. There is no wastage of materials for forming the formwork of the concrete structure since all of the component parts of the formwork of the present invention are reusable.

The described arrangement has been advanced by \\melbfiles\homeS\PClarke\Keep\specis\Formwork Arrangement Doherty.doc 6/06/02 19 explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination of features herein disclosed.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described.

It is understood that the invention includes all such variations and modifications which fall within the spirit and scope.

\\melb-fies\homeS\PCarke\Keep\specis\o-ork Arrangement Dohertydoc 6/06/02

Claims (36)

1. A formwork arrangement, jig, device or similar for forming a structure having a wall provided with a fitting or similar extending at least partially from or through the wall including a first wall forming member extending from a level or position corresponding to a first base line or base level of the wall of the structure being formed to a level near to or corresponding to the top of the wall of the structure being formed; and a second wall forming member extending from a level or position corresponding to a second base line or level of the wall of the structure being formed to a level near to or corresponding to the top of the wall of the structure being formed, second wall forming members being spaced apart from each other for forming the wall of the structure therebetween, the first base line or level and the second base line or level being spaced apart from each other such that the space between the two base line levels associated with the second wall forming member is open wherein the second wall forming member is provided with an adjustable cover means for covering the open space in use of the formwork arrangement such that the position of the cover means is adjustable to accommodate the fitting when located in or through the open space to substantially cover or close the open space thereby allowing the wall of the structure to be formed between the two wall forming members from the first base line level to a level corresponding to the top of the structure.

2. A method of forming a wall of a structure having a fitting extending therefrom or passing through the wall including the steps of forming a base for the structure; locating a formwork arrangement on the base of the structure, wherein the formwork arrangement includes a first wall forming member extending from a level or position corresponding to the level of the base of the structure to a level near to or corresponding to the top \\melbfiles\home$\PClarke\Keep\specis\Formwork Arrangement Dohertydoc 6/06/02 21 of the structure being formed and a second wall forming member, said first and second wall forming members being spaced apart from each other for forming the wall of the structure therebetween and the space between the base of the structure and the lower part of the second wall forming member located above the base of the structure being open; positioning the fitting on the base adjacent the first wall forming member of the frame work arrangement to extend below the second wall member through the open space, adjusting the position of an adjustable cover means for covering or closing the open space formed by the second wall forming member between the base of the structure and the lower level of the second wall forming member to substantially cover or close the open space; introducing material from which the structure is being made into the gap between the second wall forming members; allowing the material to stand for a predetermined time to allow the material to attain a degree of structural integrity or be self-supporting, removing at least a part of the formwork arrangement from the wall of the structure, thereby forming the wall of the structure.

3. An apparatus or method according to claim 1 in which the material from which the structure is made is concrete.

4. A apparatus or method according to any preceding claim in which the structure is formed in an excavation pit or similar and is preferably an inspection pit, junction box, block or similar. An apparatus or method according to any preceding claim in which the structure is the inspection pit of a drainage or sewerage system from which one or more pipes extend.

6. A method or apparatus according to any preceding claim in which the structure is substantially rectilinear \\melb_files\home$\pClarke\Keep\specis\Forwork Arrangement Doherty.doc 6/06/02 22 having four walls arranged to extend substantially perpendicularly to each other.

7. A method or apparatus according to any preceding claim in which the base of the structure is provided with a uniform upper surface or a non-uniform upper surface having a rebate in the upper surface or in a wall or a stepped arrangement or similar.

8. A method or apparatus according to any preceding claim in which the first wall forming member is one of a plurality of similar wall forming members, preferably one of four wall forming members connected together to form a box-like structure.

9. A method or apparatus according to any preceding claim in which the first wall forming members are arranged as an inner wall. A method or apparatus according to any preceding claim in which the second wall forming member is spaced apart from the first wall forming member by the thickness of the wall being formed therebetween.

11. A method or apparatus according to any preceding claim in which there are four second wall forming members interconnected together to form a box-like structure forming the outer walls of the formwork.

12. A method or apparatus according to any preceding claim in which there is one or more adjustable leg arrangements provided on one or more of the outer walls.

13. A method or apparatus according to any preceding claim in which the adjustable leg is provided with a foot portion in the form of a flange, bracket or similar, preferably an L-shaped bracket or flange.

14. An apparatus or method according to any preceding claim in which the adjustable legs and/or feet are for forming rebates in the base of the structure or in the structure itself or in the upper surface of the base of the structure. A method or apparatus according to any preceding claim in which the formwork is provided with a height \\melbfiles\home$\pClarke\Keep\specis\Formork Arrangement Doherty.doc 6/06/02 23 adjustment means, preferably a jack and more preferably a screwjack.

16. A method or apparatus according to any preceding claim in which the height adjustment means is located at each of the corners of the formwork, preferably the corners of the outer wall of the formwork.

17. A method or apparatus according to any preceding claim in which the height adjustment means includes an externally threaded shaft capable of rotation at a fixed location with respect to the form work and an internally threaded tube for receiving one end of the threaded shaft therein so that rotation of the shaft causes axial movement of the tube to adjust the height of the form work by one end of the tube contacting the ground in the vicinity of the corner of the form work.

18. A method or apparatus according to any preceding claim in which the fitting is a pipe, conduit, cable or the like.

19. A method or apparatus according to any preceding claim in which there are two, three, four or more fittings provided in the walls of the inspection pit being formed by the formwork. A method or apparatus according to any preceding claim in which there is a single pipe associated with one or more of the selected wall sections or with all of the wall sections of the structure by the pipe extending from or through the wall section or sections.

21. A method or apparatus according to any preceding claim in which the pipes extend perpendicularly or angularly from the walls.

22. A method or apparatus according to any preceding claim in which the cover means is adjustable, preferably in the lengthwise extending direction, and more preferably in both the lengthwise extending direction and the width.

23. A method or apparatus according to any preceding claim in which the cover means includes a plurality of adjustable cover elements, preferably a plurality of \\melbfiles\home\PClarke\Keep\specis\Formwork Arrangement Doherty.doc 6/06/02 24 individually adjustable cover elements.

24. A method or apparatus according to any preceding claim in which the adjustable cover elements include elongate elements extending lengthwise from at or towards the base of the structure to an intermediate location between the base and top of the formwork structure. A method or apparatus according to any preceding claim in which the cover means includes a plurality of lengths of timber, metal or the like.

26. A method or apparatus according to any preceding claim in which the individual adjustable elongate elements are located in spaced apart channels or brackets located on the outer wall of the formwork.

27. A method or apparatus according to any preceding claim in which the lengths of timber are adjustable around the periphery of the fitting, pipe or similar to close or cover the open space formed by the outer wall so as to substantially retain concrete in an unset state in the space of gap between the inner wall and the outer wall.

28. A method or apparatus according to any preceding claim in which the individually adjustable elements are provided with retaining means for retaining the elements in selected desired positions during use of the formwork.

29. A method or apparatus according to any preceding claim in which the retaining means are bolts, pins, clips, clamps, fasteners or the like for securely holding the elements, preferably against the form work. A method or apparatus according to any preceding claim in which the inner wall structure or box-like structure is provided with one or more lifting brackets.

31. A method or apparatus according to any preceding claim in which there is one or more brackets extending from the outer surface of the inner wall to the inner surface of the outer wall.

32. A method or apparatus according to any preceding claim in which there are four brackets located one at each corner interconnecting the inner wall arrangement and the \\melb.files\homeS\PCarke\Keep\specis\Formork Arrangement Dohertydoc 6/06/02 25 outer wall arrangement.

33. A method or apparatus according to any preceding claim in which there is a hollow elongate sleeve welded to the inboard end of one or more of the brackets.

34. A method or apparatus according to any preceding claim in which the outer wall arrangement is provided with a first transverse rail and a second transverse rail in which the two transverse rails are spaced apart from each other wherein a first set of rectangular channels are provided in the first transverse rail and the second set of rectilinear channels are provided in the second transverse rail for receiving the individually adjustable cover elements. A method or apparatus according to any preceding claim in which the adjustable cover elements are located in a raised position when the formwork is being located in situ, preferably located in an excavation such that the lower edge of the inner wall arrangement rests on the upper surface of the base of the structure.

36. A method or apparatus according to any preceding claim in which the individually adjustable cover elements can be positioned so as to rest upon either the base of the structure, the floor of the excavation or on the fitting.

37. A method or apparatus according to any preceding claim in which a concrete base is first formed on the floor of the excavation.

38. A method or apparatus according to any preceding claim in which the formwork is lowered into excavation by a suitable lowering means, such that all of the individually adjustable cover elements are in a raised position.

39. A method or apparatus according to any preceding claim in which the fittings or pipes are positioned so that the inboardly directed open end of each fitting or pipe abuts against the outer surface of the lower part of the inner wall arrangement. \\melbbfiles\homeS\PCarke\Keep\specis\Formwork Arrangement Doherty.doc 6/06/02 26 A method or apparatus according to any preceding claim in which the retaining means is released to allow the individually adjustable covering elements to adopt an in use position.

41. A method or apparatus according to any preceding claim in which concrete is poured into the gap between the inner wall and the outer wall to form a wall therebetween.

42. A method or apparatus according to any preceding claim in which the inner wall is raised slightly above the base level.

43. A method or apparatus according to any preceding claim in which the inner wall portion is axially or slidably moveable with respect to the outer wall portion.

44. A method or apparatus according to any preceding claim in which there is initial movement of the inner wall portion followed by simultaneous movement of the inner and outer wall portions. A method or apparatus substantially as hereinbefore described with reference to the accompanying drawings. Dated this 6th day of June 2002 PAUL MICHAEL DOHERTY By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia \\melbfies\homeS\PClarke\Keep\specis\Formork Arrangement Dohertydoc 6/06/02