Compactible inner formwork assembly for forming a concrete building shaft

Abstract

An inner form assembly for forming a concrete building shaft includes plate quarters and corner posts therebetween. Each corner post has an angled interface surface that converges toward the exposed orthogonal skin surfaces. The plates have respective angled interface surfaces that abut the respective angled interface surfaces of the corner posts, such that the plates are held orthogonally by the corner posts. The angled interface surfaces of the corner posts and plates slidably press against each other and mechanically engage with catches that slide along grooves, such that when the corner posts rise relative to the plates, the plates move together to form a compacted cross-sectional configuration, and when the corner posts fall relative to the plates, the plates move outward to form an expanded cross-sectional configuration, with the orthogonal skin surfaces aligning with the respective skin surfaces of the adjacent plates.

Description

[Technical Field]

[0001] The present invention relates generally to forms, and more particularly, the present invention relates to a compactible inner form assembly for forming a concrete building shaft. [Background technology]

[0002] Concrete formwork used in the building industry creates molds for concrete to use in forming various building elements such as walls, columns, shafts, etc. After the concrete has hardened, the formwork is removed and the hardened concrete is left in place.

[0003] When forming tubular building elements, it is desirable to have a compactible formwork, some of which include US 5,230,907 A (STRICKLAND) of July 27, 1993 (hereinafter referred to as D1) for the pre-fabrication of tubular concrete segments in factories, which includes a horizontally acting hydraulic ram and inner formwork assembly that retracts and compacts the opposite corners; US 4,614,326 A (STRICKLAND) of September 30, 1986 (hereinafter referred to as D2) which is designed to form catch basins using a similar hydraulic ram arrangement; SU 1361276 A2 (KAZAK PI ORGANIZATSII T STR KA) of December 23, 1987 (hereinafter referred to as D3); and SU 939694 A1 (ALMA ATINSKIJ) of June 30, 1982, which employs vertically moving corner elements to retract the side panels. DOMOSTROITEL) [hereinafter referred to as D4], and IT MI20092357 A1 (SETTEN GENESIO SPA) of 31 March 2010 [hereinafter referred to as D5], which uses a pivoting arm to retract the beveled edge corner section.

[0004] The present invention seeks to provide a collapsible formwork assembly that overcomes or substantially ameliorates at least some of the drawbacks of the prior art and overcomes the problems associated with forming shafts for multi-storey buildings, or at least provides an alternative.

[0005] Where prior art information is referenced herein, it should be understood that such reference does not constitute an admission that the information forms part of the common general knowledge in the art in Australia or any other country. Summary of the Invention

[0006] Provided herein is an inner form assembly for forming a concrete building shaft having plate quarters and corner posts therebetween. Each corner post has an angled interface surface that converges toward the exposed orthogonal skin surfaces. The plates have respective angled interface surfaces that abut the respective angled interface surfaces of the corner posts, such that the plates are held orthogonally by the corner posts. The angled interface surfaces of the corner posts and plates slidably press against each other to allow the corner posts to move perpendicularly relative to the plates and are mechanically interlocked with catches that slide along grooves, such that when the corner posts rise relative to the plates, the plates move together to form a compacted cross-sectional configuration, and when the corner posts fall relative to the plates, the plates move outward to form an expanded cross-sectional configuration, with the orthogonal skin surfaces aligning with the respective skin surfaces of the adjacent plates.

[0007] The present formwork assembly may have a particular geometry that is particularly suited to forming multi-story shafts such as lift shafts, stairwells, etc. on-site, as opposed to the factory pre-fabricated cast assemblies of D1, catch basin forming apparatus of D2, or the relatively short arrangements taught by D3-D5.

[0008] In this regard, the inner formwork assembly can be over 4m high so that the shaft section for an entire floor can be formed at once, and once the shaft has been formed in stages, the inner formwork assembly can be conveniently hoisted between floors using a crane.

[0009] Specifically, the inner form assembly may have a particular geometry that allows a relatively large surface area plate to peel from the concrete and / or provides sufficient clearance for lifting the form assembly up the shaft using a crane.

[0010] Specifically, the groove may have a height to horizontal extent ratio of greater than 5, preferably about 7 or greater, to harness the vertical force of the crane into horizontal force sufficient to peel the slab from the concrete surface inside the shaft using the crane alone.

[0011] Additionally, the exposed orthogonal skin surfaces of the corner posts may have a relatively small width compared to the arrangements taught by D1 or D2 to minimize surface contact area and prevent the posts from sticking to the concrete when lifted by a crane. In this regard, each orthogonal skin surface may have a width of less than 50 mm, preferably less than about 40 mm. Furthermore, the ratio of each corner post interface surface to that of the respective orthogonal skin surface may be greater than 4, preferably greater than 5, thereby allowing sufficient contact surface for the structural integrity of the assembly.

[0012] Additionally, the ratio of the horizontal extent of each groove to the width of each orthogonal skin surface may be greater than 1, such that each corner post has a greater range of movement along a diagonal axis compared to the range of movement of each plate along an orthogonal axis between the expanded and compacted cross-sectional configurations. Preferably, the ratio is greater than 1.5.

[0013] Thus, the horizontal extent of each groove can be configured to allow each board to move in excess of 30 mm, preferably in excess of about 40 mm, thereby providing up to 80 mm of clearance along each axis of the form assembly. This is particularly useful because plywood nails often protrude 25-30 mm from the surface of the board, which would otherwise interfere with lifting the form assembly by crane without this sufficient clearance.

[0014] Other aspects of the invention are also disclosed.

[0015] Notwithstanding any other forms that may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 10 shows an exploded view of the inside of a corner portion of an inner form assembly according to an embodiment. [Figure 2] 10 shows an outer perspective view of the corner in the expanded configuration. [Figure 3] 10 shows an outer perspective view of the corner in the compacted configuration. FIG. [Figure 4] 10 shows an enlarged view of the outside of the corner in the expanded configuration. [Figure 5] 10 shows a close-up view of the inside of the corner in the expanded configuration. [Figure 6] 10 shows an enlarged view of the outside of the corner portion in the compacted configuration. [Figure 7] 10 shows an enlarged view of the inside of a corner portion of the compact configuration. [Figure 8] 10 shows a top view of the corner in the expanded configuration. [Figure 9] 10 shows a top view of the corner in a compact configuration. [Figure 10] Exemplary dimensions of the corners are given. [Figure 11] FIG. 10 shows a side view of the grooves in the corner posts of the assembly. [Figure 12] FIG. 1 shows a top view of the assembly in an expanded configuration. [Figure 13] FIG. 1 shows a top view of the assembly in a compacted configuration. DETAILED DESCRIPTION OF THE INVENTION

[0017] Referring to Figure 12, inner form assembly 100 includes quarters of plates 101 and corner posts 102. Referring to Figure 8, each corner post 102 includes an angled interface surface 103 that converges toward an exposed orthogonal skin surface 104.

[0018] Plate 101 has angled interface surfaces 105 that meet the angled interface surfaces 103 of each of corner posts 102 so that plate 101 is held orthogonally by corner posts 102 as shown in FIG.

[0019] 5 and 7, the angled interface surfaces 103, 105 slidably press against one another so that each corner post 102 can rise vertically relative to the adjacent plate 101 as shown in FIG. 5 and fall vertically relative to the adjacent plate 101 as shown in FIG. 7.

[0020] Additionally, the angled interface surfaces 103, 105 mechanically engage with a catch 106 that slides along a groove 107. The groove 107 angles outward toward its upper end. In the embodiment shown in FIGS. 5 and 7, the grooves 107 are angled in pairs, each engaging a respective fastener 106 that passes therethrough. Additionally, with reference to FIG. 1, the grooves 107 may be positioned along the length of the post 102. In the embodiment shown in FIG. 1, the post 102 includes four pairs of grooves 107.

[0021] The arrangement of grooves 107 and catches allows the plates 101 to move together to form the compacted cross-sectional configuration shown in Figures 9 and 13 when the corner posts 102 are raised relative to the plates 101 as shown in Figure 5. Additionally, when the corner posts 102 are lowered relative to the plates 101, the plates 101 move outward to form the expanded cross-sectional configuration shown in Figures 8 and 12, with the orthogonal skin surfaces 104 aligned with the respective skin surfaces 108 of the plates 101 as shown in Figure 8.

[0022] In the expanded configuration, the orthogonal skin surfaces 104 are exposed.

[0023] Each post 102 may include a lifting lug 109. In use, the lifting lugs 109 may be attached to a crane hook by a respective chain to pull up the post 102 and enable the form assembly 100 to assume the compacted configuration.

[0024] As shown in FIG. 1, each post 102 may be formed from a metal sheet to form the open channel portion shown in FIG. 1. Additionally, the board 101 may be formed with a corresponding wedge-shaped portion 110, which may also be formed from a metal sheet. The catches 106 may be attached to the interior interface surfaces 105 of the metal wedge-shaped portions 110. The wooden battens 111 may be attached to right-angled edges 115 of the wedge-shaped portions 110, to which the other components of the board 101 may be attached. In this regard, the board 101 may comprise wood panel work on 300 mm centers, with an 18 mm plywood face plate, held together using 3 inch nails.

[0025] The wedge-shaped portion 110 may include a window 116 to allow access to the face of the batten 111 to drive a wood screw 117 into the wood panel work. The corner post 102 may include a corresponding window 118.

[0026] The interface surfaces 103, 105 may include additional locking catches 119 that interconnect with corresponding notches 120 to provide additional support and structural support to the assembly 100 when the assembly 100 is in the expanded configuration.

[0027] Each post 102 may have a height of more than 4m, preferably 4.5m, to allow for the formation of a shaft across the floor.

[0028] This arrangement of metal and wood components provides structural resilience to the interacting corners of the assembly 101, but exposes a plywood skin surface that is better suited to peeling from the concrete.

[0029] 11, each groove 107 may have a vertical extent v and a horizontal extent h. The ratio of vertical extent v to horizontal extent h may be greater than 5, preferably greater than 7. In the embodiment shown, the vertical extent is about 450 mm, while the horizontal extent is about 65 mm, resulting in a ratio of about 6.9.

[0030] This ratio converts the vertical force exerted by the crane into a horizontal force sufficient to separate the plate 101 from the concrete.

[0031] 10, each orthogonal skin surface 104 may have a width of less than 50 mm, preferably less than about 40 mm. Thus, in use, the relatively narrow orthogonal skin surfaces 104 have less exposed surface area in contact with the concrete when the assembly 100 is in an extended configuration to allow peeling when the corner posts 102 are initially pulled upward by a crane.

[0032] 10, the ratio of the width of the corner post interface surfaces 103 to the width of the respective orthogonal skin surfaces 104 can be greater than 4, and preferably greater than 5. Thus, the assembly 100 provides sufficient interface surface contact area between the interface surfaces 103, 105 for structural integrity while exposing a minimum of the skin surfaces 104.

[0033] Additionally, the ratio of the horizontal extent h of each groove 107 to the width of each orthogonal skin surface 104 may be greater than 1 so that each corner post 102 has a greater range of movement along the diagonal axis 112 shown in FIG. 9 compared to the range of movement of each plate 101 along the orthogonal axis 113 between the expanded and compacted cross-sectional configurations. The ratio is preferably greater than 1.5.

[0034] Thus, the horizontal extent h of groove 107 may be configured to allow each plate 101 to move along an orthogonal axis in excess of 30 mm, preferably in excess of about 40 mm, thereby providing a total clearance of 80 mm along each orthogonal axis 113. Thus, assembly 100 can be removed from the shaft with sufficient clearance to avoid protruding nail heads and the like.

[0035] 11 having a horizontal range of 65 mm, each corner post 102 would move 65 mm along the diagonal axis 112, and the plate 102 could move only as defined by the width of each orthogonal skin surface 104, in this case 40 mm, along the orthogonal axis 113. In the embodiment shown in FIG. 9, the device 100 could be positioned so that the distal tips 114 could come within 10 mm of each other or even touch as shown in FIG. 9.

[0036] Forming a vertical building shaft using the apparatus 100 involves installing the apparatus 100 on-site and assembling an outer form around it, thereby defining a rectangular form between them into which rebar can be inserted. may include:

[0037] Concrete can be poured into the form and allowed to harden.

[0038] Four quarters of chain may then interconnect with each lifting lug 107 of the corner posts 102 and be attached to a crane hook. When the crane hook is pulled up, each post 102 is also pulled up.

[0039] As mentioned above, the relatively small surface area of ​​the exposed orthogonal skin surfaces 104 allows the exposed surfaces of the corner posts 102 to peel away from the concrete so that they do not stick when the corner posts 102 are initially lifted by the crane 102. As further mentioned above, the angle ratio of groove 107 provides sufficient leverage to convert the lifting force applied by the crane into a greater horizontal force sufficient to peel slab 101 from the concrete.

[0040] In the compacted configuration shown in FIG. 13, the assembly 100 can have up to 80 mm of clearance along each orthogonal axis 113, thereby allowing a crane to lift the assembly to the next upper position without interference from protruding objects such as plywood nails.

[0041] At the next upper position, the corner post 102 can be lowered relative to the board so that the assembly 100 assumes the expanded configuration shown in FIG. 12, and the process is repeated.

[0042] As can be appreciated, this process avoids the need for specialized hydraulic pumps, screw jacks, etc., minimizes human intervention, and essentially allows the crane itself to quickly and easily hoist the assembly 100 into position above as the shaft is incrementally formed.

[0043] The foregoing description, for purposes of explanation, used specific terminology to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that specific details are not required to practice the present invention. Thus, the foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teachings. The embodiments have been chosen and described to best explain the principles of the invention and its practical application, so as to enable others skilled in the art to best utilize the invention and various embodiments, with various modifications, as suitable for the particular uses contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

[0044] The term "about" or similar terms, as used herein, unless otherwise indicated, should be interpreted as within 10% of the stated value.

Claims

1. An inner form assembly comprising: four quarters of the plate with wedge-shaped portions; four corner posts respectively positioned between the four quadrants of the plate, each corner post having an interface surface angled with respect to the quadrants of the plate, the interface surfaces of the corner posts converging toward the exposed orthogonal skin surfaces; An inner form assembly comprising: the wedge-shaped portions of the plate quadrants have interface surfaces angled relative to the corner posts, the interface surfaces of the plate quadrants abutting the interface surfaces of each of the corner posts, and the plate quadrants are held orthogonally by the corner posts with the interface surfaces of the corner posts and the interface surfaces of the plate quadrants abutting each other; the interface surfaces of the corner post and the plate quarters slidably bear against one another and are mechanically engaged with a catch that slides along a groove, the catch being provided in the interface surfaces of the plate quarters, the groove being provided in the interface surface of the corner post, the groove being angled relative to the corner post toward an outer side of the inner form assembly toward an upper end of the groove, and the groove being disposed along the length of the corner post, so that: as the corner posts rise relative to the plate quarters, the plate quarters move inwardly of the inner form assembly to form a compacted cross-sectional configuration; as the corner posts are lowered relative to the plate quadrants, the plate quadrants move outwardly of the inner form assembly to form an expanded cross-sectional configuration, with the orthogonal skin surfaces lining up flush with the respective skin surfaces of adjacent plate quadrants; Inner formwork assembly.

2. An inner formwork assembly as described in claim 1, wherein the ratio of the vertical extent to the horizontal extent of the groove is greater than 5.

3. 3. The inner form assembly of claim 2, wherein the inner form assembly has a height of more than 4 m.

4. 4. The inner form assembly of claim 3, wherein the ratio is about 7.

5. 5. An inner form assembly according to claim 4, wherein the vertical extent is about 450 mm and the horizontal extent is about 65 mm.

6. The inner form assembly of claim 1 , wherein the ratio of the width of the corner post interface surface to the width of each orthogonal skin surface is greater than four.

7. The inner form assembly of claim 6 , wherein the ratio is greater than 5.

8. 7. The inner form assembly of claim 6, wherein each of the orthogonal skin surfaces has a width of less than 50 mm.

9. 9. The inner form assembly of claim 8, wherein the width is less than about 40 mm.

10. The inner form assembly of claim 1 , wherein each of the orthogonal skin surfaces has a width of less than 50 mm.

11. 11. The inner form assembly of claim 10, wherein the width is less than about 40 mm.

12. 2. The inner form assembly of claim 1, wherein the ratio of the horizontal extent of each groove to the width of each orthogonal skin surface is greater than 1 so that, between the expanded cross-sectional configuration and the compacted cross-sectional configuration, each corner post has a greater range of movement along a diagonal axis compared to the range of movement of each plate quadrant along an orthogonal axis, the orthogonal axis being an axis perpendicular to the plate quadrants and the diagonal axis being an axis passing through opposite distal tips of each corner post.

13. The inner form assembly of claim 12 , wherein the ratio is greater than 1.

5.

14. 14. An inner form assembly according to claim 13, wherein each plate quarter moves more than 30 mm along orthogonal axes.

15. 15. The inner form assembly of claim 14, wherein each plate quarter moves more than about 40 mm along orthogonal axes.

16. 2. The inner form assembly of claim 1, wherein each corner post includes a lifting lug that, in use, is attached to a crane to pull up on the corner post and enable the inner form assembly to assume the compacted cross-sectional configuration.

17. The inner form assembly of claim 1 , wherein each corner post is formed from sheet metal.

18. The inner form assembly of claim 1 , wherein the board quarters are provided with wooden battens.

19. 20. The inner form assembly of claim 18, wherein the wedge-shaped portions of the plate quadrants are formed from metal plate.

20. 20. The inner form assembly of claim 18, wherein the catches are attached to interface surfaces of wedge-shaped portions of the plate quadrants.

21. An inner formwork assembly as described in claim 18, wherein the wooden battens are attached to right-angled edges of the wedge-shaped quarter sections of the boards.

22. 22. An inner form assembly according to claim 21, wherein wood panel work is attached to the wood battens.

23. 23. An inner form assembly according to claim 22, wherein the wedge-shaped quarter sections of the boards include windows to allow access to the faces of the wood battens to allow wood screws to be driven into the wood panel work.

24. 24. An inner form assembly according to claim 23, wherein each corner post includes a window corresponding to a window in a wedge-shaped portion of one of the plate quadrants.

25. 2. The inner form assembly of claim 1, wherein interface surfaces of the plate quarters and the corner posts include additional locking catches that interconnect with corresponding notches when the inner form assembly is in the expanded cross-sectional configuration.

26. The inner form assembly of claim 1 , wherein the grooves are arranged such that in the compacted cross-sectional configuration, the distance between opposing distal tips of each corner post is 10 mm or less.

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