GB2271407A

GB2271407A - Fluid couplings

Info

Publication number: GB2271407A
Application number: GB9320671A
Authority: GB
Inventors: Paul Forster
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-10-12
Filing date: 1993-10-07
Publication date: 1994-04-13
Also published as: GB9221387D0; GB9320671D0

Abstract

A fluid coupling has a unitary body member which at one end is formed with a spigot (5) and at the other end a threaded portion (15) to connect to a pipe. Intermediate said ends the body member has an integral flange (9) and a threaded surface (13) for a nut, so that it can be clamped on to a bulkhead through which it projects. The unitary form of the body member provides a relatively simple and compact construction. <IMAGE>

Description

FLUID COUPLINGS The present invention relates to fluid couplings, such as for connecting fluid braking systems of towing vehicles to the braking systems of trailers, although it is not necessarily so restricted.

In some of the coupling systems that are known in the art (an example of which is shown in Figure 1) a spigot member A of a conventional compression fitting is threadedly engaged with a tapered thread on one end portion of a bulkhead fitting B and a pipe-fitting nozzle C is connected to the taper-threaded opposite end portion of the bulkhead fitting via an adaptor D. The bulkhead fitting has an annular projection E extending from its outer surface adjacent a third threaded portion F which lies between the two end portions. The fitting is secured in place by abutting the annular projection against a vehicle bulkhead when the body member is passed through a hole therein, and clamping it by a nut engaging with the threaded portion F of the fitting to bear against the opposite surface of the bulkhead.

These prior art coupling systems have been derived piece-meal from standardized components. They have a number of obvious disadvantages (e.g. the number of parts, the multiplicity of potential leak-paths) for which no effective solution has been suggested before the present invention.

The present invention provides in a first embodiment a unitary body member for pipe couplings having a spigot at a first end portion, means for engagement of a pipe end fitting at a second end portion and means for connection to a bulkhead intermediate said end portions. The means for connection to the bulkhead preferably comprises an annular projection which is integral with the body member and an externally threaded portion of the body member for engagement of a nut or collar, so that the nut and projection can bear against opposite surfaces of the bulkhead to hold the body member in a fixed position relative to the bulkhead.

The present invention has a number of advantages over the aforementioned prior art systems. Firstly, there are advantages of increased safety. Unlike the present invention, the multi-component systems need careful assembly and checking to ensure that they do not come apart in use. Secondly, the present invention avoids three of the joints of the known systems, each of which is a potential leakage path.

Couplings provided by the present invention may have an internal surface of uniform cross-section over most of their length, providing good flow properties.

There is generally no need for discontinuities in the internal flow bore other than a narrowing of the internal diameter of the body member where required for the compression pipe fitting. The known multi-component systems have discontinuities in their internal surfaces at each of the joints between separate components, which can have a significant effect on fluid flow.

Couplings according to the present invention may be much smaller in the axial direction than the known multi-component units referred to above. This size reduction is advantageous in avoiding wastage of space within the body of a vehicle and is particularly useful when a fluid line must be angled in a restricted space for connection to the coupling members. In addition, a smaller and simpler article such as can be provided by the present invention is cheaper to produce than the known apparatus.

The present invention will now be explained further by description of an embodiment with reference to Figure 2 of the accompanying drawings in which Figure 1 is an axial section of a known form of fluid pipe coupling, and Figure 2 is an axial section of one embodiment of a unitary body member of a pipe coupling according to the present invention.

A unitary body member 1 of the pipe coupling as shown in Figure 2 has a continuous passageway 3 passing therethrough. A tapered spigot 5 forms a first end portion of the body member 1. The spigot 5 has an annular recess 7 in its outer surface to receive locking means which, in known manner, may be part of female coupling member.

An annular projection 9 having an axial dimension sufficient for rigidity and strength extends from the outer surface of a cylindrical intermediate portion 11 of the body member 1. On the far side of the projection 9 from the spigot 5, the cylindrical portion 11 has a threaded surface 13 for engagement by a nut.

The body member 1 has an externally threaded portion 15 forming a second end portion thereof, which is suitable for connection of a pipe. The internal surface of this second end portion 15 is tapered outwards towards its outer face. Within the passageway 3 an inwardly projecting ridge 17 adjacent the tapered end portion 15 provides a constricted region of narrow internal diameter. The outer diameter of the end portion 15 is less than the outer diameter of the intermediate portion 11 of the body member 1.

In use the pipe-fitting second end portion of the body member 1 is passed through a hole in a bulkhead until the projection 9 abuts against one face of a vehicle bulkhead. A nut is then threaded onto the surface 13 of the body member and tightened until the bulkhead is tightly clamped between the nut and the projection. A pipe end fitting is then threadedly engaged over the end portion 15 of the body member 1.

Claims

CLAIMS:

1. A fluid coupling comprising a unitary body member with a continuous passageway passing therethrough, wherein a spigot member is formed integral with a bulkhead connection means and with means for connection to a pipe end fitting.

2. A coupling according to claim 1 wherein the spigot forms a first end portion of the body member, the means for connection to a pipe end fitting is an externally threaded nozzle forming an opposite end portion and, intermediate said end portions, the bulkhead connection means comprises an annular projection and an axially adjacent screw-threaded portion for an external nut or collar.

3. A coupling according to claim 1 or claim 2 wherein the body member passageway has a uniform crosssection over a major part of its length.

4. A coupling according to claim 3 where an inwardly projecting ridge towards said second end portion forms a constriction of the said passageway, between the first end portion and said ridge the passageway having a uniform cross-section.

5. A unitary fluid coupling member having an elongate passageway extending therethrough, a first portion of the unitary member at one end of the passageway having a cylindrical peripheral surface formed with a screw-thread for connection to a pipe, a second portion of the unitary member of the opposite end of said passageway forming a tapered spigot, and a portion of the member intermediate said first and second portions being formed with a peripheral projection and a cylindrical threaded surface adjacent said projection for attachment of the member to a support.

6. A fluid coupling substantially as herein described with reference to Figure 2 of the accompanying drawings.

7. A body member for a fluid coupling according to any one of the preceding claims.