AU774832B2 - A connection device - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE

SPECIFICATION

STANDARD

PATENT

Invention Title: A CONNECTION

DEVICE

Applicant: TUBE ENTERPRISES PTY LTD The following statement is a full description of this invention, including the best method of performing it known to me: 1A A CONNECTION DEVICE The present invention relates to a device for connecting panels together. The invention has particular application to connecting pre-cast concrete building panels and will herein be described in this context. However, it is to be appreciated that the present invention is not limited to this specific use. In this respect, it is to be appreciated that the term "building units", as used in this specification, includes precast concrete slabs, footings, building blocks and the like.

When constructing buildings from pre-cast concrete panels, it is desirable, and indeed usually necessary, to secure the panels to a footing(s) to prevent movement of the panels in the case of earthquakes, vehicle collisions and the like. Likewise, it is desirable, and generally necessary, to secure adjacent panels together to achieve further building strength.

Several devices have been used in the past to connect panels to footings and/or to adjacent panels. One disadvantage of these devices is that they are liable to fail when placed under large loads.

Therefore, it would be desirable to provide an improved connection device when compared to existing devices.

According to one aspect of the present invention there is provided a device o for defining a void in a building unit, the void including a first opening for receiving a connection member from an adjacent building unit, and a second void opening for receiving packing material into the void to pack around the connection member, wherein the device is an elongated tube with the first S•and second openings provided at opposite ends of the tube.

30 The device of the present invention is designed to create a female l°:connecting member, in the form of a void, in a building unit to enable a male to Femanh rrnemoiren k betveen nAdjnt buidrng ijnjts 1+ ;L nniconari4 that the male connection member would be provided in the form of a dowel of bar .:l.i WAM:VoADaZnvSpedQ4791. I s repo. doc 2 stock or reinforcement rod/strut extending from a footing or adjacent unit.

However, other types of male connection members could also be used.

According to another aspect of the present invention there is provided a building unit including at least one device for defining a void in the building unit, wherein the void includes a first opening for receiving a connection member from an adjacent building unit, and a second void opening for receiving packing material into the void to pack around the connection member.

It is to be appreciated, however, that the aperture for receiving the male connection member and the aperture for inserting packing material into the void could be the same aperture.

While it is preferable to pack material into the void around the male connection member to maximise the strength of the connection between units, satisfactory connection between units could (in some applications) be achieved without using packing material.

The device being in the form of an elongated tube, creates an elongated cavity for receiving an elongated reinforcement rod or the like.

It is to be appreciated the device could be constructed of any practical size or g shape, with the size and shape being, at least in part, dependent upon the 25 corresponding size and shape of the male connection member to be received within the void. In one form, the device could be tubular in shape with either a circular or ellipsoidal cross-section.

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S...g W:WaryO\Davi\SpeCgA24798 1St repft doc When manufacturing a building unit, it is envisaged that the device would be placed into the mould for the creation of the building unit, such as in the mould of a pre-cast concrete slab. In the case of the device being in the form of a tube, it is preferred that the tube is placed within the mould such that at least one, and preferably both, ends extend outwardly beyond a wall(s) of the building unit. In this way at least one access aperture(s) is provided to enable access to the void.

Any practical number of devices could be incorporated into a building unit, with the number being dependent, at least in part, on the desired strength of the connection between adjacent units, as well as on the cost of manufacturing the unit. In this respect, it is to be appreciated that increasing the number of individual connections between adjacent units increases the connection strength between units.

Preferably, the device is provided with removable closures at its ends. These are fitted to prevent material filling the void during forming of the building unit.

Once the unit has been manufactured, the closures can then be removed to expose the -apertures leading to the void. The removable closures can assume any practical form, including screw threaded caps, friction fitted caps and the like.

Preferably, the device is designed such that it remains integrated within the building unit. However, it is to be appreciated that the device could be designed such that it is removable from the building unit if desired.

*6 Preferably, the device is relatively inexpensive to manufacture. This is Co desirable because the device is generally intended to be remain integrated within the building unit. In one form the device is constructed from plastic by S- C 30 mass production techniques.

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t Preferhablyv the devirce inck!des a behnd, sciirh that the void created can include apertures on adjacent faces of the building unit. This is desirable because, in the case of securing a pre-cast concrete slab to a footing, the W:\orla\oXavn\SDecf 24798.O1 .do 4 male connection member extending upwardly from the footing is required to be inserted into a void in the slab via an aperture provided in the downwardly facing slab face. In this arrangement, it is desirable that the aperture provided for filling the void with packing material around the inserted male connection member be provided on one of the sidewalls of the slab, to enable it to be relatively easily accessed. In one form the device includes an approximately 90 degree bend. However, it is to be appreciated that the device could include differently angled bends, if desired.

In the case of pre-cast concrete slabs, the packing material could be concrete or similar, so as to rigidly secure the male connection member within the void.

Preferably, the device includes at least one rib extending inwardly and/or outwardly from the surface of the device. In one particularly desired form, the device includes a plurality of ribs alternating inwardly/outwardly from the surface of the device along the length of the device, and extending at least partially around the circumference of the device. This arrangement is desirable because it assists in securing the device rigidly within the building unit, and prevents accidental removal of the device from the building unit. It also creates a stiffer device than would be possible without ribs.

It has also been found that the provision of ribs can provide a connection between building units of improved strength. This is due, at least in part, to 25 the increased surface area of the device because the ribs increase the contact area between the male and female connection members. This, in turn, enables high loads within the male connection member to be uniformly distributed into the building unit of the female connection member, thereby greatly reducing the possibility of connection failure between connected 30 building units.

Drfprolhh, =ho= rlki% io oAvnonrlohl In -a nrfrrri frrm +hie ic nrhitKhl, by providing a means for connecting extension units to the device, thereby enabling the size of the void created to be varied to accommodate differently W:\tont aDav rSpei\24798-01 .doc sized male connection members. However, this could also be achieved by forming the device from several separate pieces which are telescopically extendable.

Preferably, the device is constructed from a highly visible colour so that its ends extending from the building unit can be easily seen. This assists in the alignment of building units when the units are being connected.

To assist with understanding the present invention, reference will now be made to the accompanying drawings, which illustrate one embodiment of the invention. The particularity of the drawings is to be understood as not limiting the preceding broad description of the invention.

In the drawings: Figure 1 illustrates a perspective view of one form of the device of the present invention.

Figure 2 illustrates a cross-sectional front view of the device illustrated in Figure 1 when used in the connection of a precast concrete slab to a footing.

Figure 3 illustrates a cross-sectional side view of the arrangement illustrated in Figure 2.

Figure 1 illustrates a device according to the present invention in the form of a hollow tube 1. The tube 1 includes flanges 2 (not clearly visible) extending 25 along opposing longitudinal sides of the tube 1. The flanges 2 are provided to increase the stiffness of the tube 1.

Radially extending ribs 3 are provided around the tube 1. The ribs 3 form part of the sidewall of the tube 1. The ribs 3 alternatively extend above the 30 general surface of the tube 1. The ribs 3 are provided to, inter alia, increase the contact area of the connection between building units (refer to Figures 2 S.nd 3 qnrd tn inrnnsa tha trannth nf tha tfubh 1 °o co: oooeoo W:Vona\Dav.S ped\2479-01 .doc 6 The tube 1 includes a bend 4. The.tube 1 also includes apertures 5 and 6 at its respective ends. The apertures 5 and 6 lead to a common void within the tube 1. The aperture 5 is for receiving a male connection member, in the form of a steel dowel pin (see Figures 2 and Once the steel dowel pin is inserted through the aperture 5, a packing material in the form of wet concrete (not illustrated) in poured through the aperture 6. Once the packing material sets, the steel dowel pin is securely retained within the void of the tube 1.

The tube 1 may be extended by connecting extension pieces (not illustrated) onto one or both of ends 5 and 6. These can be retained in place via retaining tabs 7.

Referring to Figures 2 and 3, male connection members in the form of prepositioned steel dowel pins 9 are placed in (and extend from) a building unit, in the form of a footing 10. When a building unit, in the form of a pre-cast concrete panel 8, is lowered into position onto the footing 10, steel dowel pins 9 are seated within the voids 11 created by the devices in the form of the tubes 1. A packing material in the form of grouting mixture 12 is then poured/pumped into the voids 11 via apertures 6. The grouting mixture 12 at least substantially fills the voids 11, including filling the spaces created by the ribs 3, and around the steel dowel pins 9. Once the grouting mixture has :cured, a secure bond forms between the pre-cast concrete panel 8 and the footing The presence of the ribs 3 increases the surface area of the tube 1, and also increases the effective contact area between the steel dowel pins 9 and the concrete panel 8 once the grouting mixture 12 hardens. Accordingly, when the steel dowel pins 9 are loaded, the forces are transferred to the annular 30 ribs 3. Due to the increased surface area the ribs 3 provide, a larger shear stress cone 13 (refer to Figure 3) is produced, thereby more uniformly the likelihood of a connection failure when a load force is applied to the connection.

W:\tonia'Davin\Sped\24798-1 .doc 7 It is to be appreciated that the dimensions of the dowel pin and the tube 1 can be varied as desired. However, the applicant considers that a preferable ratio between the inner surface area of the tube 1 and the surface area of the dowel pin 9 is approximately 10 to 1. However, it is to be appreciated that the surface area ratio provided above can be varied to suit the specific application or applications required.

It is to be understood that alterations, modifications and/or additions may be introduced into the construction and arrangement of the parts herein described without departing from the spirit or ambit of this invention.

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Claims (19)

1. A device for defining a void in a building unit, the void including a first opening for receiving a connection member from an adjacent building unit, and a second void opening for receiving packing material into the void to pack around the connection member, wherein the device is an elongated tube with the first and second openings provided at opposite ends of the tube.

2. A device according to claim 1, wherein the void is capable of receiving a connection member from an adjacent building unit in the form of a reinforcing member or the like.

3. A device according to claim I or 2, wherein the tube is approximately L- shaped.

4. A device according to any one of the preceding claims, wherein at least one of first and second openings include a removable closure.

A device according to claim 4, wherein the removable closures are screw threaded caps.

6. A device according to claim 4, wherein the removable closures are efriction fitted caps. 25

7. A device according to any one of the preceding claims, wherein the device is manufactured from plastic. e*

8. A device according to any one of the preceding claims, including at least one rib extending inwardly and/or outwardly from the surface of the device.

9. A device according to claim 8 including a plurality of ribs arranged along I I U V 0t rAl 8lW L AiLLl I lCALty, OllV iA III I I liv, It Jl, i 1llt"d I LVV IgI iy I 1 II.Jl Ii Li i ts ,Lli iLAtL I the device.

I*l a W:WayatO "D8vtl'Speon24798-01 I sl rpofrtloc 9 A device according to claim 9, wherein each of the plurality of ribs extends at least partially around the circumference of the device.

11. A device according to any one of the preceding claims, wherein the device is extendable.

12. A device according to claim 11, wherein the device is telescopically extendable.

13. A device according to claim 11, wherein the device is extendable by attaching extension elements.

14. A device according to any one of the preceding claims, wherein the device is manufactured from a material which is highly visible in colour.

A building unit including at least one device for defining a void in the building unit, wherein the void includes a first opening for receiving a connection member from an adjacent building unit, and a second void opening for receiving packing material into the void to pack around the connection member.

16. A building unit according to claim 15, wherein the device is integrated into the building unit during manufacture of the building unit.

17. A building unit according to claim 15 or claim 16, wherein the building see 25 unit is a concrete slab.

18. A building unit according to any one of claims 15 to 17, wherein the device ends extend outwardly from the surface of the building unit. 30

19. A device for defining a void in a building unit substantially as herein described and illustrated. *ft W: aryO\ovMlSped 24798-01.1st reon. doc A building unit substantially as herein described and illustrated. DATED: 17 May 2004 PHILLIPS ORMONDE FITZPATRICK Attorneys for: TUBE ENTERPRISES PTY LTD. Le S. S .5 5*SS S 0O S S IS I 5 'S S 5.5. S IS 8.*S S S V:WaYOMDavtnSPeCA'247W8O11st report doc