GB2047368A - Pipe coupling system - Google Patents

Abstract

A pipe joint system for attaching pipes to their fittings, particularly adapted for use with smooth surface pipe and tubing where assembly and disassembly is easily made with simple tools or without tools, comprises a one piece split retaining sleeve 1 which has at least one row of tangs or lugs 8, bent radially inwardly to engage the outside of the pipe and the fitting respectively. A clamping device 4 holds the sleeve in position. A second row of lugs 9 may be provided. Grooves (14, 15, Fig. 3 not shown) may be provided to improve the grip between the lugs 8 and 9 and the pipe 7 and the fitting 3 respectively. The joint is sealed by an annular gasket 12 sealed in a groove 11. <IMAGE>

Description

SPECIFICATION Pipe coupling system The invention is in the field of readily applicable and removable couplings for effecting joints between pipes and their fittings.

The invention is intended especially for use with smooth-surfaced pipes and tubing and their fittings such as re normally used in known and conventional methods of assembly such as threading soldering, glueing, brazing or welding.

There is a need for a simple device to connect pipes to their fittings that is economical, not only to manufacture, but also in actual installation and use.

Such a device, to achieve the greatest economy, must permit easy assembly, equally easy disassembly, and must permit the salvage of the maximum amount of components of the system; this device according to the invention permits the reusage, time after time, of all components provided their integrity is safeguarded.

It is known that disastrous fires were caused, directly or indirectly, by the use of open flame or by the emanation of inflammable fumes and their subsequent ignition during the installation or alteration of plumbing systems; this device according to the invention eliminates these hazards since no flammable components, heat or flame is required for its installation.

According to the present invention there is provided a pipe joint system comprising a one piece wrap-around split retainer sleeve for preventing a pipe inserted into a fitting from separating from said fitting, the retainer sleeve having two opposed rows of spring-like lugs, spaced apart longitudinally relative to the axis of the pipe, the lugs being inclined to the axis of the pipe, the inner ends of the lugs of each row lying in the same plane, transverse to the longitudinal axis of the retainer sleeve to respectively engage in the exterior perimeter of the pipe and the exterior perimeter of the fitting's end, the retainer sleeve being mechanically held in place by fastening means.

It is known that lack of thorough deoxydation and cleaning of the components of plumbing systems requiring soldering or glueing results in weak or leaking joints, which in turn require dismantling and re-installation, sometimes at the cost of a number of new and extra fitting and material and great expense of time. The preferred device according to the invention as described below, does not require such thorough deoxydation and cleaning, resulting in savings of time, because it relies on its composition seal for fluid tightness.Most known systems of pipe joints depend on their purpose-made fittings, ordinarily compatible only within their own system, to function and their adaptability to different systems is very limited if non-existent; the device according to the invention makes use of fittings normally used with other conventional joining methods without recurring to their hazard-prone joining techniques and favours adaption of this invention with other joining methods wherever tolerances between components permit.

This flexibility permits the creation of hybrid systems where one side is joined conventionally and the other side with the coupling subject of this disclosure.

Most known systems of pipe joints require the use of tools in the assembly and disassembly of the coupling or fitting; devices according to the invention can be made which offer the choice between hand or tool operable clamping means, which in hand operable clamping means offers an obvious time saving potential to the user.

A major weakness in a coupling system is that its retaining means can accidentally be released while the system is pressurised. Preferably this undesirable feature is overcome in the device as only wilful release of the retainer sleeve, while the system is pressurised, may result in loss of fluid tightness.

Some known systems of pipe joints depend on grooves in the pipe ends to mechanically secure the pipes to their fittings, said grooves being ordinarily square edge in profile to ensure more positive and non-slip contact of retaining lugs. The device according to the invention may make similarly use of a groove in the end of the pipe and of the fitting to ensure a positive grip of the lugs both on the pipe and on the fitting end in a very different way as explained hereafter.

This groove must be distinguished from the gasket seating groove whose function is solely related to the fluid tightness of the system, this first mentioned groove shall be called slipresisting groove as opposed to the gasket groove.

The slip resisting groove need not be square in profile but may be of any profile suitable to provide slip resistance for the lugs of the retainer sleeve, depending on the pipe or fitting material this slip resisting groove can be square, V-shaped or rounded according to the characteristics of the pipe or fitting material and the easiest method of forming such groove.The profile of the slip-resisting groove is dictated by the stress characteristics of the material of the pipe and/or fitting; a rounded groove profile offers the benefit of minimising the occurrence of localised stress points, ordinarily found to be the cause of failure, and provides an infinity of contact planes parallel to the end plane of the lugs; this is particularly important as it provide automatic adjustment for varying lug angles relatively to the pipe longitudinal axis, especially under varying pressure loads.

It is known that soldered fittings can be unsoldered only when the fitting and the pipe adjacent thereto are completely drained; since the device according to the invention does not require any heat in order to be removed but only unlocking of the retainer sleeve, it is now clear that no time is wasted draining the system.

This feature of easy removal leads to other potential economies since any such retainer sleeve used in conjunction with an end cap or any other type of fitting at low points of plumbing systems will act as a low cost drain.

Further research led to the present disclosure wherein a combination of the above described and some other desirable features are incorporated.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings of which:~ Figure 1 is a perspective view of the retainer sleeve showing one preferred embodiment of the invention fitted on one end of a (Tee) fitting; Figure 2 is a section through the connection end of a (Tee) fitting showing the relative position of the components of the system using thin wall tubing; Figure 3 is a detail section showing the use of slip resisting grooves with optional gaskets on lugs and shoulders, said slip resisting grooves being required only on pipes and fittings of such hardness as to prevent the lugs from safely gripping on the pipes and fittings; Figure 4 is a transverse section of the retainer sleeve showing the lug arrangement and a symbolic clamping means; and Figure 5 illustrates two preferred toolless clamping means.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral 1 indicates a metal retainer sleeve, which in Fig. 1 is wrapped around the end 2 of the fitting 3 and held in place by a clamping means 4. The retainer sleeve 1 consists of a strip of spring-type material with its ends turned inwardly towards the axis to form two unequal shoulders 5, notched 6 to permit easy bending around the pipe 7 and the fitting end 2. The retainer sleeve 1 exhibits one row of long sloping tangs or lugs 8 are struck out of the metal of the sleeve and bent radially inwardly. The lugs 8 slope away from the end of the sleeve and towards the fitting end 2 and engage into the exterior surface of the pipe 7. A second row of short sloping lugs 9 are bent in a similar but opposed direction to engage into the exterior surface of the fitting end 2.

The retainer sleeve 1 engages by means of the short 9 and long 8 lugs respectively the fitting end 2 and the pipe 7 in a wrap around fashion, the opening 10 permitting the installation of the retainer sleeve 1 without need for dismantling the pipe-fitting assembly 7 and 3.

The tightening or loosening of the clamping means 4 permits the securing or removing respectively of the retainer sleeve 1 to or from the pipe-fitting assembly.

A rounded gasket seating groove 11 is rolled, or otherwise fabricated at a predetermined distance from the end of the pipe 7.

The groove receives an annular gasket 12, or 0 ring, which makes the joint fluid-tight. The composition of the gasket 12 should be compatible with the type of fluid handled in the system and the type of material constituting the system.

Referring to Fig. 3, the shoulders 5, the short 9 and the long 8 lugs are wrapped with a resilient material 13, which provides for even pressure distribution on the pipe 7 or fitting end 2; this optional protection is intended, among other things, to lessen pipe 7 or fitting 3 breakage due to thermal or mechanical stress built-up in brittle or fragile pipe 7 or fitting 3 material.

Referring to Fig. 3, a slip-resisting second groove 14 on the pipe 7 end is fabricated in a similar manner to the groove 11 for the gasket 12. The second groove 14 acts as a mechanical stop providing slip resistance to the long lugs 8. A similar arrangement in the form of a groove 15 is fabricated in the exterior surface of the fitting end 2 at a predetermined distance. The groove 15 acts as a mechanical stop for the short lugs 9 providing slip resistance against forces induced by pressure within the system.

Fig. 5 shows in dotted lines the profile of two retainer sleeves 1, each displaying a preferred clamping means 4, with which the retainer sleeve 1 can be installed or removed without the use of tools. This illustrates some of a multitude of clamping means 4 suitable for the system according to design requirements. In one case the clamping means comprises a spring strap and a tensioning lever.

One end of the spring strap engages a slot in the sleeve, the other end is tensioned by the lever which fits into a slot in the sleeve on the other side of the split in the sleeve. The lever has a toggle like action so that when the lever is pressed against the sleeve, the sleeve is clamped in place. In the other case, the clamping means comprises a spring strap with two loops for resilience and hooks on the ends for engaging slots on opposite sides of the split.

Many adaptions of the system are possible.

For example, the short lugs 9 and the adjacent shoulder 5 may be replaced with a retaining means in the form of screw type serrations, lugs to fit in grooves or adaptable to screws screwable in the fitting body 3.

Joints made according to the disclosure are quite simple to make: Firstly the pipe 7 is prepared with a suitable tool by rolling or otherwise fabricating a groove 11 or a plurality of grooves 11-14 at a predetermined distance from the end of the pipe 7 in order for the first groove 11 to be completely lodged inside of the fitting end 2 when the pipe 7 is forced into said fitting end 2.

Secondly an annular gasket 12, or 0 ring, is slipped over the pipe end 7 and seated in the first groove 11 to provide for the fluid tightness of the system once inserted into the fitting end 2.

Thirdly the fitting end 2 is inspected for smoothness and cleanliness and the prepared pipe 7, loaded with its sealing gasket 12, is inserted into the fitting end 2 until it butts against the inside shoulder or stop of the fitting 3. The groove provides a visual control over the seating of the gasket since the gasket in the groove is visible until it penetrates the fitting.

Fourthly the retainer sleeve 1 is opened and slipped over and around the pipe 7, positioned over the fitting end 2 and part of the pipe 7, at this point the clamping means 4 is tightened and the system is ready for testing and subsequent use.

At this stage, it should be checked that the lugs are falling into their respective slip-resisting grooves when these are provided. Under normal conditions slip-resisting grooves are not required or used and no checking other than that the pipe is fully inserted is required before applying the clamping pressure.

Reversing the procedure permits equally easy disassembly. Reassembly, omitting step one, is immediately possible without further preparation of the components provided they are not damaged.

Claims (9)

1. A pipe joint system comprising one piece wrap-around split retainer sleeve for prevent a pipe inserted into a fitting from separating from said fitting, the retainer sleeve having two opposed rows of spring-like lugs, spaced apart longitudinally relative to the axis of the pipe, the lugs being inclined to the axis of the pipe, the inner ends of the lugs of each row lying in the same plane, transverse to the longitudinal axis of the retainer sleeve to respectively engage in the exerior perimeter of the pipe and the exterior perimeter of the fitting's end, the retainer sleeve being mechanically held in place by fastening means.

2. A pipe joint system according to claim 1, wherein the ends of the retainer sleeve are turned inwardly towards the axis to form shoulders resting respectively on the exterior of the pipe and on the exterior of the fitting end for preventing distortion and shifting of the retainer sleeve under clamping pressure.

3. A pipe joint system according to claim 2 wherein the shoulders are fitted with gaskets to distribute the pressure equally on the inserted pipe and fitting.

4. A pipe joint system according to claim 1, 2 or 3 including an annular gasket and in which a groove is formed in the pipe at a predetermined distance from the end of the pipe in such a way that when the grooved pipe is pushed into the mouth of the fitting, the annular gasket is visible until it penetrates the fitting.

5. A pipe joint system according to claim 1, 2, 3 or 4 wherein grooves are formed in the pipe and the fitting at predetermined distances from the end of the pipe and of the fitting respectively, to match the position of the lugs of the retainer sleeve when the pipe fits correctly in the fitting; the grooves each creating a positive mechanical stop for the respective rows of lugs of the retainer sleeve.

6. A pipe joint system according to claim 1, 2, 3, 4 or 5 wherein the retainer sleeve lugs are fitted with a gasket to distribute the pressure equally on the inserted pipe and fitting and to minimize breakage due to ther mal or mechanical stresses.

7. A pipe joint system according to claim 1, 2, 3, 4, 5 or 6 in which the fastening means comprises one or more clamps or spring buckles.

8. A pipe joint system including a one piece wrap-around split clampable retainer sleeve for preventing the pipe to separate from its connection point, said retainer sleeve being fitted on the pipe side with one row of spring-like lugs, longitudinal to the axis of the pipe and axially directed in a sloping fashion with their inner ends in the same plane, transverse to the longitudinal axis of the retainer sleeve towards the connection point to engage in the exterior perimeter of the pipe and, on the connection point side with axially inwardly curved lugs, axially outwardly curved lugs with screw fastening provisions, or screw type serrations suitable to the connection point embodiment.

9. A pipe joint system substantially as hereinbefore described with reference to Fig.

1 to 4 or Figs. 1 to 4 as modified by Fig. 5, of the accompanying drawings.