AU743592B3 - Plate dowell assembly - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT Name of Applicant: Actual Inventor(s): DAN LEY CONSTRUCTION PRODUCTS PTY LTD Address for Service: Invention Title: Details of Associated Provisional Application No:

INTELLPRO

Patent Trade Mark Attorneys Level 7, Reserve Bank Building 102 Adelaide Street BRISBANE, QLD, 4000 (GPO Box 1339, BRISBANE, 4001) PLATE DOWEL ASSEMBLY Australian Patent Application No. PQ9279 filed 8 August 2000.

The following statement is a full description of this invention, including the best method of performing it known to me: 2 PLATE DOWEL ASSEMBLY FIELD OF THE INVENTION THIS invention relates to a plate dowel assembly for construction of joints between concrete slabs of the type employing dowels bridging across the joint to allow "conventional dowel action" of relative movement of the slabs in the plane of the slabs while keeping the slab surfaces aligned.

BACKGROUND TO THE INVENTION In its most basic form a dowelled slab has dowels held in parallel spaced relation with one end of each dowel greased to prevent it adhering to the concrete.

The most common dowel is made from cylindrical bar. Dowels have always ***been difficult to align parallel in practice. Various means have been used in an effort to hold dowels parallel. These include plastic dowel holders secured to form work and so on.

S,

OUTLINE OF THE INVENTION 15 An object of the present invention is to provide a dowel system that improves the alignment of dowels but also uses flat plate rather than conventional dowels both to make alignment simpler but also to improve dowel loading.

In one aspect therefore the present invention resides in a plate dowel assembly for concrete slabs comprising a first longitudinal rail and a second longitudinal rail, parallel spaced plate dowels bridging between and supported at opposite ends of the dowels by respective dowel holders, the rails serving to hold the plate dowels in predetermined relation relative to slabs being poured, spaced rail connectors bridging between the rails holding the rails at spaced relation, the 3 rail connectors being used in situ to disconnect the rails and thereby release the rails so that the dowels adopt a conventional dowel action in situ.

The rails are typically identical being formed from welded together steel bars, each rail comprising upper and lower bars and spaced uprights. The spaced uprights are welded to the upper and lower bars, each upright typically extends to form a said dowel holder and has a generally U-shaped return projecting above the upper bar, the U-shaped return holding one end of a dowel plate between the upper bar and the return.

So that the whole assembly can be prefabricated in the factory and shipped 10 to the site, the dowels are preferably fixed at one end to one rail. The dowels could .of course be placed in position on site. Each dowel plate typically has a fixed end and a free end, the fixed end being fixed by being welded to one rail. In the usual way the other end of the dowel can be greased to ensure that it is released from the slab. However, it is preferable that each dowel plate is housed at one end in a 15 cover instead of being greased, the cover being wider than the dowel plate and having compressible material held on either side of the dowel plate to allow limited transverse relative movement between slab and dowel.

Where covers are employed, the dowel holders at each end are of different width relatively narrow at one end to accommodate the plate at one end and relatively wide at the other end to accommodate the wider case at the other end.

While the plate dowels can be arranged at any configuration it is preferable that the free end fixed end alternate on opposite rails along the assembly. Thus the case of covers also alternate along the rails.

4 BRIEF DESCRIPTION OF THE DRAWINGS In order that the present invention can be clearly understood and put into practical effect the description will now refer to the drawings which show nonlimiting embodiments of the invention, wherein:- Figure 1 is a plan view of a plate dowel assembly according to the present invention; Figure 2 is a section through A-A of Figure 1; and Figure 3 is a section through B-B of Figure 1.

METHOD OF PERFORMANCE 10 Referring to the drawings there is illustrated a plate dowel assembly comprising side rails 11 and 12, the side rails being made from upper and lower bars 13, 14, 15 and 16 respectively welded to opposed uprights 17 and 18, the uprights 17 and 18 having generally U-shaped returns 19 and 20 respectively that serve to hold plate dowel assemblies 21 in position.

The plate dowel assemblies 21 include a plate dowel, in this case made from 2 inch wide by 3/8 inch thick and 12 inches long steel plate, the plate dowel being housed at one end in a plastic cover 22 having compressible material at 23 and 24 on opposite sides of the plate 25. The dowel assemblies being positioned in alternating configuration along the assembly. The plates are each welded at one end to the rails 14 or 16 in alternating fashion as shown but are free to slide within the cover 22.

Each of the rails is connected together and held in spaced relation by connecting wires 26 located along the assembly and once the assembly is placed in position prior to pouring the concrete slab then the wires 26 can be cut thereby freeing the rails and allowing the dowels to operate.

The uprights 17 and 18 are inclined, the rails usually being tied to steel in situ to support the rails and dowels when the wires 26 are cut. Once the bars 26 are severed the rails 13, 14 uprights 17, 18 as may be specified are tied into the steel in the respective slabs the concrete can be poured and it will be appreciated that the plate dowels 25 will be held in substantially parallel spaced alignment. There compressible material at the sides of the covers will take up any transverse loading.

Oo°•Whilst the above has been given by way of illustrative example of the present invention many variations and modifications thereto will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as set out in the appended claims.

o•0o.

•0o

Claims (3)

1. A plate dowel assembly for concrete slabs comprising a first longitudinal rail and a second longitudinal rail, parallel spaced plate dowels bridging between and supported at opposite ends of the dowels by respective dowel holders, the rails serving to hold the plate dowels in predetermined relation relative to slabs being poured, spaced rail connectors bridging between the rails holding the rails at spaced relation, the rail connectors being used in situ to disconnect the rails and thereby release the rails so that the dowels adopt a conventional dowel action in

2. A plate dowel assembly according to claim 1 wherein the rails are formed o from welded together steel bars, each rail comprising upper and lower bars and spaced uprights, the spaced uprights being welded to the upper and lower bars, each upright extending to form a said dowel holder and has a generally U-shaped return projecting above the upper bar, the U-shaped return holding one end of a o° :said plate dowel between the upper bar and the return. *ooo

3. A plate dowel assembly according to claim 1 or Claim 2 each plate dowel has a fixed end and a free end, the fixed end being fixed by being welded to one rail and the free end being housed in a cover, the cover being wider than the plate dowel to allow limited transverse relative movement between slab and dowel. DATED this TWENTY-SECOND day of MAY 2001 DANLEY CONSTRUCTION PRODUCTS PTY LTD By its Patent Attorneys INTELLPRO