GB2322177A - Pipe fitting with longitudinal projections for engaging a pipe - Google Patents

Abstract

The fitting comprises a mouth portion 3 for receiving a pipe end, said mouth portion being provided with internal sealing means 9 to seal between the pipe fitting and the pipe end, the free end of the mouth portion being provided with integral, peripherally spaced apart, longitudinal projections 5, said fitting further including a collar 13 which, when the pipe end is positioned within the mouth portion of the fitting, is movable axially so as to surround said projections 5 and compress them into engagement with said pipe end. The projections 5 have integral end flanges 7 for engaging a pipe groove or metal inserts for biting into the pipe surface.

Description

PIPE FITTINGS This invention relates to pipe fittings and, in particular, to pipe fittings for connection to at least one pipe and in order, for instance, to provide a connection to another pipe end.

The present invention is concerned primarily, though not exclusively, with pipe fittings for use with metal pipes, for example, pipes made of stainless steel.

It is well known to provide a pipe fitting which includes a mouth portion which is oversized relative to the end of the pipe to be received thereby. The fitting is then joined to the pipe end by the use ofjointing material such as solder.

The soldering of stainless steel pipes is not straightforward and particular care has to be taken if a satisfactory joint is to be obtained. Consequently, there is a need to develop a pipe fitting which does not require the use of solder and yet provides a very firm sealed joint.

According to the present invention there is provided a pipe fitting for connection to at least one pipe end, the fitting comprising a mouth portion for receiving a pipe end, said mouth portion being provided with internal sealing means to seal between the pipe fitting and the pipe end, the free end of the mouth portion being provided with integral, peripherally spaced apart, longitudinal projections, said fitting further including a collar which, when the pipe end is positioned within the mouth portion of the fitting, is movable axially so as to surround said projections and compress them into engagement with said pipe end.

At least some of the longitudinal projections are preferably provided with radially inwardly directed tips or flanges. When the collar is pushed into position about the projections, these inwardly directed flanges will engage with the surface of the pipe end, thereby ensuring a good connection. In order to assist the firm connection even further, it is preferred that the pipe end is provided, for instance by machining, with an external annular groove into which the inwardly directed flanges may locate.

The pipe fitting is preferably provided with an internal groove or recess into which is fitted an O-ring or other sealing means.

The pipe fitting may be made of any suitable material. For instance, it may be made entirely of metal, for example, stainless steel, apart from the O-ring or other sealing means. As an alternative the body of the fitting may be made of metal, for example, stainless steel and the compression collar may be made of plastics material.

The pipe fitting may form part of a straight coupling for connecting two pipe ends together. In this case, the pipe fitting may be provided with two identical pipe receiving end portions. Alternatively, the fitting may have end portions of different diameters to provide a connection between pipes of different diameters.

The fitting may be provided with one end which has a different type of connection, for instance, an internal or external screw-threaded portion.

The pipe fitting may be other than a straight coupling, for instance, a tee connector, a cross connector or a bend, for example, a 90 degree elbow or a 45 degree bend.

Furthermore, the fitting may be of various other types, for instance, a simple end cap.

An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figure 1 is a longitudinal section of an end of a pipe fitting in accordance with the present invention; and Figure 2 shows the end of a pipe to which the fitting of Figure 1 may be connected.

Referring to the accompanying drawings, a pipe fitting 1 in accordance with the present invention includes a mouth portion 3, the whole of which is shown in Figure 1. Mouth portion 3 of pipe fitting 1 is of broadly cylindrical shape. Over much of its length, mouth portion 3 is in the form of integral, peripherally spaced apart, longitudinal projections or fingers 5. By way of example, a pipe fitting for use with a 15 mm pipe may have twelve such projections equally spaced apart, each having a peripheral width of about 2.5 mm and the spacing between adjacent projections being about 1.5 mm.

The free end of each projection 5 is slightly enlarged to form an inwardly directed tip, edge or flange 7.

Adjacent the other ends of projections 5, mouth portion 3 of pipe fitting 1 includes an annular recess 9 which, viewed from the exterior of fitting 1, is in the form of an annular, integral collar. Within this collar is located the annular recess into which is fitted an O-ring 11. The dimensions of the recess 9 and the O-ring 11 are such that, when fitted in position within the recess, O-ring 11 projects inwardly slightly out of the recess.

Adjacent recess 9, on that side remote from projections 5, is an integral annular stop 13 which extends radially inwardly from the inner surface of the mouth portion 3 of pipe fitting 1.

Pipe fitting 1 is also provided with a separate compression collar 13 in the form of a ring having a length slightly greater than that of projections 5 and one end of which is formed with an integral, inwardly directed flange 15. The inner edge of flange 15 has a diameter which is the same as the inner surface of the mouth portion 3. The diameter of the inner surface of the main part of collar 13 is such that it is slightly less than the outer surface of the main part of mouth portion 3. As illustrated in Figure 1, compression collar 13 may be pushed over the projections 5 of mouth portion 3 until the end of collar 13 which is remote from flanges 15 abuts the integral collar 9, at which position flanges 15 will abut the free ends of projections 5.

In order to connect pipe fitting 1 to a pipe end, such as pipe end 17 shown in Figure 2, an external annular groove 19 is machined into the pipe at a position some distance from the absolute end of the pipe. This distance corresponds to the distance between flanges 7 of projection 5 and the nearest edge of stop 13. With compression collar 13 first located over pipe end 17 and moved to the left of groove 19 (as shown in Figure 2), the pipe end 17 is then pushed into mouth portion 3 in the direction indicated by the arrow in figure 1. This movement is continued until absolute end 21 of pipe and 17 engages stop 13, at which point ends 7 of projections 5 are positioned at the groove 19 of the pipe and 17. Compression collar 13 is now pushed over the end of mouth portion 3 until it is in the position indicated in Figure 1. During this movement, the compression collar 13 will force projections 5 radially inwardly and the ends 7 of projections 5 will firmly engage into groove 19 of pipe end 17.

It will be appreciated that, when the pipe end 17 is located within mouth portion 3, as described above, the O-ring 11 will bear upon the pipe end, thereby providing a sealed connection between the fitting 1 and the pipe end 17.

The above described pipe fitting is capable of making a very tight connection with a pipe and this connection cannot become loose during use. The fitting has only three parts, the body of the fitting including mouth portion 3, the O-ring 11 and the compression collar 13 and this results in a simple and efficient arrangement. The simplicity of the arrangement also allows the fitting to be designed with a very simple, neat appearance. The positive engagement between the fitting and the pipe means that the fitting can be located on a pipe end having any type of external surface, including a shiny surface. The fitting is extremely simple to manufacture. It can also be easily demounted from the pipe.

The present invention also provides a pipe coupling including a fitting of the invention and a pipe having an end provided with a groove or other recessed portion for engagement by the projections of the fitting.

In another embodiment, that part of the pipe fitting carrying the projections or fingers 5 may be made of plastics material. Each projection 5 may be of substantially uniform cross-section along its entire length rather than being provided with integral projections at its end. Located at the end of each finger 5, however, is a metal staple which extends inwardly from the finger end.

In this embodiment it is not necessary for the pipe, which may be made of a material such as plastics, copper or stainless steel, to be provided with a groove such as groove 19 in the above described embodiment. The collar of the fitting may be made of, for instance, metal and when pushed over fingers 5 will force the staple body into a biting engagement with the pipe.

Claims (6)

1. A pipe fitting for connection to at least one pipe end, the fitting comprising a mouth portion for receiving a pipe end, said mouth portion being provided with internal sealing means to seal between the pipe fitting and the pipe end, the free end of the mouth portion being provided with integral, peripherally spaced apart, longitudinal projections, said fitting further including a collar which, when the pipe end is positioned within the mouth portion of the fitting, is movable axially so as to surround said projections and compress them into engagement with said pipe end.

2. A pipe fitting according to Claim 1 in which at least some of the longitudinal projections are provided with radially inwardly directed portions.

3. A pipe fitting according to Claim 2 wherein the inwardly directed portions are integral with the longitudinal projections.

4. A pipe fitting according to Claim 2 in which the inwardly directed portions are provided by metal inserts extending from said projection.

5. A pipe fitting according to Claim 1 and substantially as herein described.

6. A pipe fitting substantially described with reference to the accompanying drawings.