GB2220243A

GB2220243A - Hose coupling component

Info

Publication number: GB2220243A
Application number: GB8914260A
Authority: GB
Inventors: Frederick Russell Duffield; Colin James Taken
Original assignee: Frederick Duffield Pty Ltd
Current assignee: Frederick Duffield Pty Ltd
Priority date: 1988-06-24
Filing date: 1989-06-21
Publication date: 1990-01-04
Anticipated expiration: 2009-06-21
Also published as: GB8914260D0; GB2220243B; ZA894695B

Abstract

A coupling device of a type which is appropriate to a hose end fitting and which comprises a connecting element (18) which is rotatably coupled to a spigot portion (13) of the fitting by a split ring (17). The spigot portion (13) has an axially extending bore (14), a surrounding wall (15) and a circumferentially extending groove (16) in the wall. The connecting element (18) is located coaxially and rotatably about the spigot portion (13) and it is formed internally with a circumferentially extending groove (22) which has two axially spaced regions (23 and 24). The first of the regions (23) has a depth slightly greater than the cross-sectional diameter of the split ring (17) and the second of the regions (24) has a depth which is approximately equal to one-half of the cross-sectional diameter of the split ring (17) whereby, when the split ring (17) is located in the second region (24), the split ring bridges the grooves (16 and 24) in the respective parts of the device. <IMAGE>

Description

HOSE COUPLING COMPONENT This invention relates to a coupling device of a type that may be incorporated in female coupling component for a hose or pipe.

The coupling device may be formed as a portion of a hose end fitting and it is hereinafter described in such context. However, it will be understood that the coupling device may alternatively be used as a portion of any type of hose or pipe coupling.

Hose end fittings that incorporate a female coupling component usually have a nut swaged onto an end portion of the fitting, the nut being rotatable about the axis of the fitting and being used to connect a threaded spigot of a male end fitting in fluid passage communication with a bore portion of the female coupling. These fittings have been found to be quite satisfactory under most circumstances, but problems have been encountered with large size fittings that are exposed to very high pressure loadings in the order of 5,000 psi, particularly when impact forces are encountered. End fittings that are exposed to these conditions are subjected to very high forces that load the coupling nuts in tension and tend to overstress the swaged connection between the nut and the remainder of the fitting. Similar problems are encountered in service when the nuts are over-tightened.

The present invention is directed to an arrangement which obviates the need for swaging the nut onto the fitting and which provides for a positive interconnection between the nut and the remainder of the fitting.

Broadly defined, the present invention provides a coupling device which comprises a spigot portion having an axially extending bore, a surrounding wall and a circumferentially extending groove formed in the surrounding wall. A connecting element is located coaxially and rotatably about the spigot portion and is formed internally with a circumferentially extending groove. A resilient split ring is located within and projects outwardly from the spigot portion groove to engage in the connecting element groove, the split ring serving to interconnect and permit relative rotation of the spigot portion and the connecting element. The connecting element groove or the spigot portion groove has two axially spaced regions, the first of which has a depth equal to or greater than that of the split ring and the second of which has a depth smaller than that of the split ring.

It preferably is the connecting element groove that has the two axially spaced regions such that, when assembling the connecting element to the spigot portion, the split ring is first expanded outwardly to occupy the first portion of the connecting element groove.

Thereafter, the connecting element is pushed onto the spigot portion until the connecting element groove is moved into alignment with the spigot portion groove, and the split ring springs inwardly to locate within the spigot portion groove. Thus, the connecting element is held captive to the spigot portion by the split ring but is rotatable about the axis of the spigot portion.

The connecting element preferably comprises an internally threaded nut and is hereinafter referred to as such. However, it will be understood that the connecting element may take alternative forms including, for example, the form of a bayonet type connector.

The second portion of the connecting element groove preferably has a depth such that, when it is aligned with the spigot portion groove, the combined depth of the two grooves is substantially equal to the depth of the split ring. Also, each of the grooves most preferably has a depth which is equal to approximately one-half of the depth of the split ring.

The split ring preferably has a circular cross-section, in which case the spigot portion groove and the second portion of the connecting element groove will each have a semi-circular cross-section.

The invention will be more fully understood from the following description of a preferred embodiment of a female hose end fitting as illustrated in the accompanying drawings. In the drawings: Figure 1 shows a half-sectional elevation view of the end fitting in its assembled state; Figure 2 shows an elevation view, partly in section, of salient components of the end fitting prior to assembly; Figure 3 shows an end elevation view of a split ring component of the end fitting; and Figure 4 shows a elevation view, partly in section, of components of the end fitting during assembly of the end fitting.

As illustrated, the end fitting comprises a hollow stem member 10 to which a hose 11 is secured. The hose is clamped onto the stem member by a ferrule 12.

The stem member 10 includes a spigot portion 13 at its left hand end, the spigot portion having an axially extending bore 14 and a surrounding wall 15.

A circumferentially extending groove 16 is located within the wall 15, the groove having a semi-circular cross-section and having a depth slightly greater than one-half of the diameter d of a split ring 17 which locates within the groove.

A nut 18 is located coaxially about the spigot portion 13, the nut being formed from hexagonal bar and having an internal thread 19 which is connectable with a threaded spigot portion (not shown) of an associated male fitting component. The interior of the nut also has a smooth bore portion 20 which is separated from the thread 19 by a circumferential recess 21.

The smooth bore portion 20 of the nut is a neat clearance fit on the spigot portion 13, and it incorporates a groove 22 which has two axially spaced regions 23 and 24. The first region 23 of the groove has a depth which is slightly greater than the cross-sectional depth or diameter d of the split ring 17 and it has a width which is slightly greater than the diameter d of the split ring. The second region 24 of the groove has a depth equal to approximately one-half of the diameter d of the split ring and a width equal to the diameter of the split ring.

The split ring 17, which may also be referred to a circlip, is formed from a resilient metal such as spring steel and it has an internal diameter P approximately equal to the root diameter of the groove 16.

When assembling the nut 18 to the spigot portion 13, the split ring 17 is first expanded into the first region 23 of the nut groove, as shown in Figure 4. The ring may be expanded into this region of the groove by using a tapered mandrel (not shown) and by temporarily butting the mandrel against the end of the spigot portion 13. Alternatively, the free end of the spigot portion 13 may be formed with a tapered nose to serve as a ramp for expanding the split ring during assembly of the coupling.

With the split ring 17 located within the first region 23 of the groove, the nut may be moved axially along the spigot portion 13 until the split ring aligns with and enters the groove 16. This then prevents further advancement of the nut 18, but the nut may then be moved in the reverse direction so that the split ring locates within the second groove region 24. This condition is illustrated in Figure 1.

When the split ring 17 is located in place in the groove 16, the nut may be rotated about the axis of the spigot portion and be moved back-and-forth to a small extent in the axial direction of the coupling. However, when the illustrated coupling arrangement is engaged with an associated male component and the nut 18 is tightened, the nut will b3 positioned such that the second region 24 of the nut groove overlies the split ring 17, to prevent the split ring from being expanded outwardly.

Claims

#LAIMS CLAIMs

1. A coupling device which comprises: a spigot portion having an axially extending bore, a surrounding wall and a circumferentially extending groove formed in the wall, a connecting element located coaxially and rotatably about the spigot portion and formed internally with a circumferentially extending groove, and a resilient split ring located within and projecting outwardly from the spigot portion groove to engage in the connecting element groove, the split ring serving to interconnect and permit relative rotation of the spigot portion and the connecting element; the connecting element groove or the spigot portion groove having two axially spaced interconnected regions, a first of the regions having a depth equal to or greater than that of the split ring and the second of the regions having a depth smaller than that of the split ring whereby, when the split ring is located in the second region, the split ring bridges the grooves in both the spigot portion and the connecting element.

2. The coupling device as claimed in Claim 1 wherein the groove having the axially spaced regions is formed within the connecting element.

3. The coupling device as claimed in Claim 2 wherein the second portion of the groove within the connecting element has a depth such that, when it is aligned with the groove within the spigot portion, the combined depth of the two grooves is substantially equal to the depth of the split ring.

4. The coupling device as claimed in Claim 3 wherein the second portion of the connecting element groove has a depth which is equal to approximately one-half of the depth of the split ring.

5. The coupling device as claimed in any one of the preceding claims wherein the split ring has a circular cross-section.

6. The coupling device as claimed in Claim 5 wherein the groove within the spigot portion and the second region of the groove within the connecting element each have a semi-circular cross-section.

7. The coupling device as claimed in any one of the preceding claims when in the form of an end fitting for a hose or pipe.

8. The coupling device as claimed in Claim 7 wherein the connecting element comprises an internally threaded nut and wherein the spigot portion constitutes a part of a female coupling component to which the internally threaded nut is rotatably retained by the split ring.

9. The coupling device substantially as shown in the accompanying drawings and substantially as hereinbefore described with reference thereto.