AU2011200959A1 - Slipjoint Pipe Seal - Google Patents

Abstract

A rubber pipe seal is described. This seal is to enable easier jointing of pipelines. The Slipjoint seal consists of a rubber sealing element as pictured in figure 1, with differing radii at each end 5 and straight edges joining the radii. An elongated slot is in the centre of the seal of similar shape to the outside profile. Thus making the seal essentially that of a tubular design. The inside of the seal is injected with a lubricant to enable the internal surfaces to slip on one another. David Suttie Stephen Suttie l't April 2011 Figure I Diagrammatic - Not to Scale Figure 2a Diagrammatic - Not to Scale

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION PATENT SLIPJOINT PIPE SEAL The following statement is a full description of this invention, including the best method of performing it known to me.

1 PREAMBLE 1. The present practice of joining concrete, glass-fibre reinforced cement or pipes for conveying fluids such as storm water, industrial waste, sewerage and irrigation water under moderate 5 pressure is to use a bell and spigot push-on joint sealed with a deformable rubber '0' ring. These O-Ring joints are widely used on underground lines. 2. Pipes jointed with O-Rings have some disadvantages: e When joining the pipes they will not automatically self align themselves to each other. ) e Once jointed the pipes can "back out" or un-joint themselves if not fully forced home. * When joining the pipes, difficulty can be had in forcing the two pipes together. 3. These disadvantages would be eliminated if it were possible to use a superior rubber joining ring with consideration given for the above problems. 4. It is the purpose of the Slipjoint rubber sealing ring which is the subject of this invention to achieve this objective. ) DESCRIPTION OF THE SLIP-JOINT RUBBER SEAL. 5. The Slipjoint rubber sealing ring shown diagrammatically in Figures 1, 2a, 2b, 2c and 2d and described herein enables the joining of Bell and Spigoted pipes fabricated from a wide range of materials such as concrete, plastic-lined concrete, glass-fibre reinforced cement and 5 thermoplastics such as High Density Polyethylene (HDPE), Polypropylene (APP), Acrylonitrile butadiene-styrene (ABS), Polyvinylchloride (PVC), Cellulose acetate-butyrate and Polycarbonate. This list is illustrative only and is not intended to be prescriptive or exhaustive. 0 6. The Slipjoint seal consists of two elements - a rubber sealing element and an inner lubricant. 7. The rubber sealing ring whose cross-sectional profile is shown by 1 in Figure 1 may be extruded, cut to length and joined to form a ring.

2 8. The lubricant whose location is shown in 2 in figure 1 will be applied by injection into the fully formed seal. 9. The Slipjoint rubber seal shown by I in figure 2a is placed on the male spigot of the pipe 5 shown in 2 in figure 2a with the large radius end facing towards the existing pipe and the small radius end facing toward the free open end shown as 3 in figure 2a. The two pipes are then pushed together. Where the edge of the bell makes contact with seal and engages the seal as per figure 2b. As the pipes move together the seal the seal "slips" on itself with a conveyor type action, with the lubricant providing a low friction surface on the inside of the seal. Further 3 movement of the pipes together produces more "conveyor" action of the seal as per figure 2c. Complete engagement of the seal as shown if figure 2d shows a complete rotation of the seal. This forms a fully liquid-tight seal of the two pipes. The complete rotation of the seal prevents the pipe from backing out of the seal and breaking the liquid-tight seal. 5 11. The materials that may be used for the Slip-joint seal are Ethylene Propylene terpolymers (EPDM), Styrene Butadiene Rubber (SBR), Natural Rubber, Nitrile Rubber (NBR), Chloroprene Rubber, Silicone Rubber. A Rubber Shore A Durometer hardness of between 40 and 60 may be used. ) 12. When assembled, the Slipjoint Seal and the two parallel pipes are disposed as shown in Figure 2d. Such an assembly has been shown to be leak tight with water at 100 kPa. 5 0

Claims (2)

1. 4. A Slipjoint pipe joining seal as in Claim 3, where the seal is manufactured by 10 extrusion, injection molding or compression molding of an elastomeric material.
2. 5. A Slipjoint pipe joining seal as in Claim 3, which fits onto the spigot of a pipe as in figure 2a and when compressed by the incoming pipe, rolls on itself in a "conveyor action" to enable an easy joining process, and produce a seal capable of withstanding pressure. 15 6. An Slipjoint Pipe joining seal as substantially herein described and illustrated in Figure 1, 2a, 2b, 2c and 2d. 20 25 30