AU715551B2

AU715551B2 - Inflatable rubber dams

Info

Publication number: AU715551B2
Application number: AU24968/97A
Authority: AU
Inventors: Jeffrey Bruce Cage; Geoffrey Alan Chandler; John Douglas Dickie; David Scott Kennedy; William John Oates; Graeme Ewing Russell
Original assignee: Queensland Rubber Co Pty Ltd
Current assignee: Trelleborg Queensland Rubber Pty Ltd
Priority date: 1996-06-18
Filing date: 1997-06-17
Publication date: 2000-02-03
Anticipated expiration: 2017-06-17
Also published as: AU2496897A

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "INFLATABLE RUBBER DAMS" The following statement is a full description of this invention, including the best method of performing it known to us: 2 THIS INVENTION relates to inflatable rubber dams.

The invention also relates to improved anchorages for such dams.

Inflatable (or collapsible) rubber dams can be used, for example, for raising the crest height of existing dams or reservoirs, as tidal barrages to protect against salt water contaminating irrigation supply, or to reduce the risk of upstream flooding during heavy rain periods. The dams can be inflated by using fluids such as air or water, and are easy to install, maintain and operate.

.:00 10 Examples of such dams are disclosed in AU-B-50641/79 (523045); AU-B-39895/85 (572633) and AU-B-10913/88 (591021).

In particular, in AU-B-50641/79, the inflatable body of elastomeric material has a split portion terminating at the end transverse of the body in a solid joint portion, the solid joint portion, when inflated, forming a deflector for the water flowing over the dam.

The claimed solid joint portion eliminates any folds in the body, when deflated, thereby reducing stresses and cracking.

It is considered, however, to be a disadvantage of the inflatable dam design in AU-B-50641/79 that there are considerable stress concentrations adjacent to the deflector when the body is inflated during high overflow conditions. In addition, it is a disadvantage to have longitudinal seams in the membrane adjacent to the deflector.

3 It is an object of the present invention to provide an inflatable rubber dam where the membrane forming the dam body is a bladder and does not require longitudinal seams in the membrane adjacent to the deflector.

It is a preferred object to provide a dam where the bladder has a radiused fold when deflated and it is designed to minimise stress concentration adjacent to the deflector when the membrane is inflated during high overflow conditions.

The major tensile forces in the dam act in a circumferential direction, therefore across the longitudinal seams.

It is a still further preferred object to provide a dam where the deflector angle can be varied by stiffening either the upside or downside of the deflector.

~Other preferred objects of the present invention will become apparent from the following description.

S In one aspect, the present invention resides in a method S Sof manufacturing an inflatable rubber dam including the steps of: 0V.0. :forming an inflatable dam membrane comprising a bladder with a radiused fold when the bladder is deflated; o•0 0 placing a deflector along the radiused fold on the bladder; and bonding the deflector to the bladder during a rubber 7curing process for the membrane and deflector.

4 Preferably, the bladder is a continuous bladder.

Preferably, the bladder and the deflector are respectively formed with cores of layers of woven cords, eg., nylon or polyester enclosed in rubber.

With the deflector, an effective deflector angle (as hereinafter described) can be varied by stiffening either the upside or downside of the deflector, eg., by increasing the number of layers of woven fabric or compounding kevlar or carbon fibres in the rubber above or below the centre line of the deflector.

In a second aspect, the present invention resides in an inflatable rubber dam made by the above method.

To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings in which:

S.

0o 15 FIG. 1 is a schematic side view of an installation of an 5*55 0: inflatable rubber dam in accordance with the present invention; oooo FIG. 2 is an enlarged view of the dam of FIG 1; *FIG. 2A is a schematic end view of the deflector of FIG 2 on an enlarged scale; S o• FIG. 3 is a perspective view of one embodiment of the deflector with varying discharge angles; and FIGS. 4 to 7 are schematic sectional views of second to Sfifth embodiments of the deflector; The dam 10 has a body 11 formed by a membrane 12 which forms a continuous bladder with a small radiused fold (see FIGS. 4 to 7) adjacent to a deflector 13 when the membrane is deflated. Both the membrane 12 and deflector 13 are built up with cores formed by layers of woven fabric, eg., nylon or polyester, enclosed in unvulcanised rubber.

The deflector 13 is placed on the membrane 12 along the radiused fold 14 and the membrane 12 and deflector 13 are bonded together during the curing vulcanising) of the rubber of the membrane and deflector.

The provision of the small radiused fold 14 in the 4 membrane 12, when inflated, minimises stress concentrations in the ;"'.membrane 12 adjacent to the deflector 13 during high overflow conditions. The major tensile forces in the dam act in a circumferential direction in the membrane, across its junction with the 5*4* The positioning of the deflector 13 on the membrane 12, indicated by angle c; the "effective deflector angle" being the angle of the centre line of the deflector in relation to the membrane, °o indicated by the angle 0; and/or the height h of the deflector, can be varied to suit the particular intended application.

In addition, by increasing or decreasing the number of 6 layers of the core (or using stiffening agents, eg., kevlar or carbon fibres) above or below the centre line of the deflector, the angle 0 can be varied, as shown in FIG 3.

FIGS. 4 to 7 show alternative profile sections for the deflectors 113, 213, 313, and 413. With deflector 213, the two "fingers" 213a, 213b will be forced into contact to form a substantially rigid deflector. With deflector 313, the location of the tongue 31 3a in the deflector slot 313b can be varied to vary the effective height of the deflector.

10 It will be readily apparent to the skilled addressee that other profiles can be provided for the deflector 13.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention defined in the appended claims.

Claims

2. A method as claimed in Claim 1 wherein: the bladder is a continuous bladder.
3. A method as claimed in Claim 2 wherein: the bladder and the deflector are respectively formed with cores of layers of woven cords, enclosed in rubber.
4. A method as claimed in any one of Claims 1 to 3 wherein: for the deflector, an effective deflector angle (as hereinbefore defined) can be varied by stiffening either an upside or downside of the deflector.
5. A method as claimed in Claim 4 wherein: the deflector is stiffened by increasing the number of layers of woven fabric or compounding carbon fibres in the rubber RA4/-A above or below the centre line of the deflector. 5 77 411 8
6. An inflatable rubber dam manufactured by the method of any one of Claims 1 to DATED this twenty-fourth day of November 1 999. QUEENSLAND RUBBER COMPANY PTY LTD By its Patent Attorneys FISHER ADAMS KELLY