WO2003052218A1

WO2003052218A1 - Formwork connection means

Info

Publication number: WO2003052218A1
Application number: PCT/AU2001/001497
Authority: WO
Inventors: Robert Sladojevic
Original assignee: Tiltform Design & Development Pty Ltd
Priority date: 2000-11-20
Filing date: 2001-11-20
Publication date: 2003-06-26
Also published as: AUPR153200A0

Abstract

The invention provides an improved joiner (10) for interconnecting hollow metal sideforms in end to end or orthogonal relationship, the joiner (10) being provided with at least one tubular spigot (14) which projects horizontally outwards from an end of the joiner body (11) and which slidably engages in a socket end of an adjacent sideform. Each spigot (14) has located internally thereof adjacent its outer free end an insert clip (16) which a push button detent (21) at the end of one of its limbs (17), the detent (21) being laterally movable between locked and unlocked positions. The detent (21) locates in and protrudes from a hole (22) formed in side wall (20) of spigot (14) and in use, when the spigot is fully engaged in its associated socket end of the sideform, lockingly engages in an aperture formed in the outer side wall of the sideform, to thereby interlock the sideform and the joiner (10) in abutting relationship.

Description

FORMWORK CONNECTION MEANS

This invention relates to an improved joiner for interconnecting hollow sideforms in end to end or orthogonal relationship used in the casting of concrete structures, in particular tilt-up building construction panels.

It is known to interconnect lengths of hollow metal sideform members in end to end relationship using internally located joining tubes or rods which extend into the open ends of adjacent sideform members which, after insertion of the tubes or rods, are abutted together. It is also known to use a separate joiner piece having opposite ends arranged to respectively abut against respective ends of the sideform members to be joined, and which is provided with outwardly projecting spigots which engage with a sliding fit within sockets or cavities formed in the ends of the sideform members. In each instance, the ends of the sideform members and the internally located joining tubes or spigots are mechanically locked together by means of transverse bolts which pass through aligned holes formed in the walls of the sideform members and the internal joining tubes or spigots. In practice, the use of locking bolts to interlock adjacent sideform members together has been found generally inconvenient and awkward, particularly in trying to align the holes of the various components, prior to inserting the bolts.

It is an object of the present invention therefore to provide improvements which will enable hollow metal sideforms to be easily and conveniently interconnected (and subsequently separated from one another) during the assembly (or disassembly) of the formwork for casting concrete structures.

It is another object of the present invention to provide an improved sideform joiner piece which is easy to handle and can be quickly and easily located in the ends of the sideform members being interconnected. Broadly according to this invention therefore, there is provided improved joining means for interconnecting elongate hollow metal sideforms in end to end or orthogonal relationship, said joining means comprising a joiner having a body section which has a profile shape substantially matching that of each of the sideform members to be joined, at least one end of the joiner having projecting outwardly therefrom one or more tubular spigots, wherein each said sideform has spigot receiving sockets or cavities extending inwardly from an open end thereof adapted to slidingly receive a respective said spigot, characterised by a spigot insert housed in the interior of said spigot adjacent its outer free end, said insert comprising a resiliently deflectable detent support, a detent mounted on said support and movable laterally inwards against the bias of said support, said detent locating in and protruding from a locating hole formed in a wall of said tubular spigot and arranged, in use, to engage in a respective locating hole formed in a side wall of the sideform when the spigot is fully inserted into its receiving socket or cavity.

Preferably the insert is an approximately flattened C-shaped resilient clip formed of spring metal or a suitable resilient plastics material, with the detent being fixed to the end of a deflectable limb or arm of the clip, the clip being shaped and dimensioned to snugly locate in the socket end of the spigot. Desirably, the limbs of the clip are contiguous with and extend substantially parallel to opposite inner walls of its associated spigot.

Desirably the limbs or legs of the resilient clip are of unequal length, with the limb which carries the locking detent being slightly smaller than the length of the other leg.

Preferably the locking detent is secured to the shorter limb adjacent its free distal end. The detent may be formed integrally with the limb by a moulding process. Desirably, the longer limb of the clip terminates in an enlarged head which is designed to close off the open free end of the spigot when the insert is fully inserted into the socket end of the spigot.

Desirably the shorter limb or leg has an inner planar portion, an outer planar portion vertically offset with respect to said inner portion, and an inwardly sloping intermediate portion joining said inner and outer portions, said outer portion having said locking detent projecting laterally therefrom, said inner portion making pressure contact against an inner wall of the spigot.

Desirably the joiner is provided with two pairs of outwardly projecting vertically spaced spigots projecting horizontally from opposite ends thereof, said spigots being fixedly secured to the body of the joiner by either weld means or suitable fasteners, eg rivets, each said hollow spigot being formed of rectangular metal tube.

In another embodiment of the invention, the detent is a rotatable ball bearing held captive on a deflectable wall portion of the insert.

With this invention, lengths of sideform can be very easily and readily connected to the joiner piece and locked in place by simply sliding the two components together so that the spigots slidingly engage within the open ends of the sideform. When the spigots are fully inserted, the locking detents automatically lockingly engage in their respective holes formed in the outer side wall of the sideform to thereby securely lock the sideform to the joiner piece. When the formwork is required to be disassembled, the sideforms can be readily detached from the joiner piece by simply pushing or pressing the locking detent inwardly, preferably by means of a suitable hand tool so that they can be simultaneously disengaged, and thereafter horizontally separating the sideform from the joiner piece. In order to more fully explain the present invention, several preferred embodiments thereof are described hereunder in more detail with reference to and as illustrated in the accompanying drawings wherein:

FIG 1 is a perspective view of a sideform joiner piece (parts of which are shown as cut-away) which is designed to connect two sideforms in end to end relationship;

FIG 2 is a side elevational view of the joiner piece shown in FIG 1 (again showing two of the spigots partly cut-away);

FIG 3 is an end elevational view of the joiner piece shown in FIGs 1 and 2;

FIG 4 is a partly cut-away view showing a sideform attached to an end of an end joiner piece according to a second embodiment;

FIGS 5(a) and (b) are views of the joiner clip alone shown in FIG 1; FIG 6 is an elevational view of a joiner clip fitted to a spigot of a joiner according to a third embodiment of the invention; while

FIG 7 is an elevational view, similar to FIG 6, of a joiner clip according to a fourth embodiment.

Referring to FIGS 1 to 3 of the accompanying drawings, there is shown a hollow joiner piece 10 which is designed to interconnect a pair of hollow metal sideforms (not shown) in end to end relationship, the sideforms when thus connected, having their ends abutting the opposite open ends of the joiner piece 10. The joiner piece 10 includes an elongate hollow body section 11 which, in this embodiment is formed from an extruded metal section, and has an external profile which is identical to that of the sideforms to be connected thereto. The joiner body 11 has projecting hollow spigots 14 projecting horizontally outwards from opposite ends thereof, with each of the spigots 14 being slidably received in socket ends of the sideforms. In this embodiment, the spigots 14 are formed by two separate lengths of extruded metal tube of square cross-section, each tube extending through a passageway in the body 11 so as to project to both sides thereof. Each of the metal tubes is secured to the housing 11 by weld means or fasteners.

Inside of each spigot 14, adjacent its open end, there is snugly located an approximately flattened C-shaped spring clip 16 having a pair of opposed resiliently deflectable limbs or legs 17, 18 which bear against opposite side walls 19, 20 respectively of the spigot 14.

Fixed to the outer side of limb 17 of each clip 16 is a push button detent 21 which projects laterally away from the limb 17 and locates in and protudes from a hole 22 formed in side wall 20 of the spigot 14. With the spring clip 16 inserted in position, the detent 21 is inwardly depressible against the bias of the resilient limb 17. In order to fit the clip 16 within the open end of the spigot 14, the legs or limbs 17, 18 are squeezed together and released once the detent 21 has passed through the open end of the spigot 14, the detent 21 then snap engaging in the hole 22 once the clip is fully inserted.

Referring to FIG 4, there is shown an end joiner 24 connected to a sideform 25 in end-to-end relationship. Each push button detent 21 lockingly engages in a hole 26 formed in the outer side wall 27 of the sideform 25. It is an advantage of the present invention that this locking interengagement is effected automatically once the spigots 14 are fully inserted within their socket ends 28 of the sideform 25. As the spigots 14 slide into their respective sockets or cavities 28, the buttons 21 are initially depressed and then automatically "click" into place when they align with holes 26, to thereby lock the formwork componentry together.

Referring to FIGS 5(a) and (b) of the drawings, in this embodiment, each of the connector clips 16 is formed from a spring metal strip the width of which is governed by the internal height or depth of the tubular spigot 14. In this embodiment the limbs 17, 18 of the clip 16 are of unequal length, with the limb 17 being slightly shorter than the limb 18. In order to stiffen the limb 17 which carries the locking button 21, the limb 17 has formed therein a transverse corrugation 29 intermediate the ends thereof. As shown in FIG 5(a), the locking button 21 is fixed to a planar end portion 30 of limb 17 which is offset with respect to an inner portion 31 of the limb, with the corrugation 29 connecting the portions 31 and 30. The offset between the portions 30 and 31 is designed to facilitate insertion of the clip 16 into its spigot and also its actuation when detracting the sideform from its joiner piece.

As illustrated in FIG 4, the joiner piece can be designed as an end joiner having projecting spigots projecting outwardly from one end only, to allow sideforms to be interconnected in orthogonal relationship as well as in end to end relationship.

Referring to FIG 6 of the drawings, there is shown a spigot insert clip 34 housed in the open free end of a spigot 36 according to another embodiment. The clip 35 is formed of plastic material and has a long arm or leg 37 which joins to a shorter leg 38 which terminates in a push button detent 39 which projects through a hole 40 in the wall of the spigot 36. The leg 37 has integrally formed at its outer end an end cap 42 which closes off the outer end of the spigot 36 (so as to prevent ingress of concrete slurry).

The arm 38 is resiliently deflectable to allow the detent 39 to be pushed inwards to a disengaged position whereupon the sideform can be separated from its joiner piece.

Referring to the embodiment of FIG 7, the insert clip 45 is moulded of plastic material and has a hollow body 46 which is closed at both ends, the outer end being shaped as an end cap 47 to close off the open end of the spigot 48 when the clip is fully inserted therein. In this embodiment, the detent is in the form of a captive ball bearing 49 which is resiliently mounted on one side of the clip body 46 and is arranged to snap locate in hole 50 in the wall of the spigot 48 when the clip 45 is fully inserted. The ball 49 is biased outwards by means of resiliently deflectable wall segments 52 which are flexibly hinged together at 53 and co-operate with the ball 49 to form a spring-loaded ball catch for releasably attaching a sideform to a joiner piece (similar to that shown in FIG 4).

A brief consideration of the above-described embodiments will indicate that the invention provides a very simple and effective means for interconnecting hollow sideform members in either end to end or orthogonal relationship through the use of joiners which can quickly and easily attach to the ends of sideforms without the use of separate locking bolts.

Claims

THE CLAIMS DEFINING THE INVENπON ARE AS FOLLOWS:

1. An improved joiner for interconnecting elongate hollow metal sideforms in end to end or orthogonal relationship, said joiner comprising a joiner body having a cross-sectional shape substantially matching that of the sideform member(s) to be joined thereto, at least one end of the joiner body having projecting outwardly therefrom one or more tubular spigots, wherein each said sideform has spigot receiving sockets or cavities extending inwardly from an open end thereof adapted to slidingly receive a respective said spigot, characterised by a spigot insert housed in the interior of said spigot adjacent its outer free end, said insert comprising a resiliently deflectable detent support, a detent mounted on said support movable laterally inwards against the bias of said support, said detent locating in and protruding from a locating hole formed in a wall of said tubular spigot and arranged, in use, to lockingly engage in an aperture formed in a side wall of the sideform when the spigot is fully inserted into its receiving socket or cavity.

2. An improved joiner according to claim 1 wherein said insert is a resilient clip formed of spring metal or plastics material and has a deflectable limb or arm which extends longitudinally of the spigot, said detent being mounted on said limb or arm at or adjacent the free end thereof.

3. An improved joiner according to either claim 1 or claim 2 wherein said clip has an approximately flattened C-shaped profile, wherein the limbs or legs of the clip are of unequal length, with the detent being mounted on the smaller limb, said limbs being contiguous with opposite side walls of its associated said spigot.

4. An improved joiner according to any one of the preceding claims wherein the longer limb of said clip terminates in an enlarged end cap which abuts against the end of said spigot and closes off its open free end to thereby inhibit entry of foreign material.

5. An improved joiner according to any one of claims 1 to 3 wherein the outer free end portion of the shorter limb is inwardly offset with respect to an inner portion of the limb, said inner portion making pressure contact against an inner wall of the spigot.

6. An improved joiner according to claim 1 wherein said detent is a resiliently mounted captive ball bearing located intermediate the ends of said spigot insert.

7. An improved joiner according to claim 6 wherein said spigot insert has an elongated body which is closed at its front and rear ends, said front end comprising an enlarged head which closes off the open free end of the spigot, when the spigot insert is fully inserted therein.

8. A sideform assembly which includes a pair of hollow metal sideforms joined in end-to-end relationship by a joiner made in accordance with any one of claims 1 to 7.

9. A sideform assembly according to claim 8 wherein said joiner is provided with a pair of vertically spaced spigots projecting horizontally from each of its opposite ends, said spigots being fixedly secured to the body of the joiner by weld means or suitable fasteners.