Description

The present invention relates to push-to-connect style fluid connectors and, more particularly, to a coupling assembly comprising a first coupling member extending along an axis from a leading end to a trailing end, having an exterior that includes a first locking surface and a front face at the leading end; a second coupling member extending from a receiving end to a remote end and including a receiving portion sized to receive the first coupling member, the second coupling member including a second locking surface and a flange face delimiting the receiving portion at the remote end; a retention ring positioned between the first and second coupling members, the retention ring arranged such that as the first coupling member is inserted into the second coupling member, the retention ring becomes engaged between the first locking surface on the first coupling member and the second locking surface on the second coupling member, thus retaining the first coupling member inside the second coupling member.

There are many industrial applications where a high pressure hydraulic system requires that several connections be made between a hose assembly and a component, such as a pump, motor, valve, etc. Initially there were no push-to-connect (threadless) connection systems available that could satisfactorily operate at high pressure, prior art systems hav e made use of threaded fittings to make this connection. Recently, push-to-connect style coupling assemblies have become available that can operate at high pressures.

According to US 7 543 854 B2, a coupling assembly is provided that includes a first coupling member extending along an axis from a leading end to a trailing end and having an exterior that includes a first locking surface. The coupling assembly also includes a second coupling member that extends from a receiving end to a remote end and includes a receiving portion sized to receive the first coupling member. The receiving portion of the second coupling member includes a second locking surface. A latching sleeve is positioned between the first and second coupling members and includes a bead. The latching sleeve is sized such that as the first coupling member is inserted into the second coupling member, the latching sleeve is compressed as the bead engages the second coupling member and then expands as the bead moves over the second locking surface to become engaged between the first locking surface on the first coupling member and the second locking surface on the second coupling member.

The current coupling design of snap-to-connect couplings does not meet the requirement to provide a secure electrical conducting path between the two coupling parts at all working conditions. Further, the release sleeve may cover the indication ring, which is intended to signal a safe connection, so the indication requirement is not fully met under all working conditions. Furthermore, a sealing arrangement is used in current couplings to prevent leakage. As there is a possibility of relative movement of the two coupling parts, so that the sealing is subject to tear and wear, which reduces the reliability of the connection. These problems are due to relative motion of the coupling parts, which occurs, due to assembly requirements of the components, when the assembly is not pressurized.

It is an objective of the invention to provide a coupling assembly with less relative movement of the coupling parts during operation.

The objective is achieved by the coupling assembly of claim 1. Further details and embodi- ments are subject to the dependent claims.

The coupling assembly according to the present application comprises a first coupling member extending along an axis from a leading end to a trailing end, having an exterior that includes a first locking surface and a front face at the leading end, a second coupling member extending from a receiving end to a remote end and including a receiving portion sized to receive the first coupling member, the second coupling member including a second locking surface and a flange face delimiting the receiving portion at the remote end; a retention ring positioned between the first and second coupling members, the retention ring arranged such that as the first coupling member is inserted into the second coupling mem- ber, the retention ring becomes engaged between the first locking surface on the first coupling member and the second locking surface on the second coupling member, thus retaining the first coupling member inside the second coupling member and a spring means located and compressed between said front face and said flange face. In case that the coupling is not pressurized, the spring force urges the two coupling parts into a secure relative position to each other.

According to a preferred embodiment, the spring means is an annular wave spring.

According to a further preferred embodiment, the spring means forms an electrically conducting path connecting the first coupling member and the second coupling member. Advantageously, there is an additional conduction path realized via the spring.

According to a further preferred embodiment, the spring means exerts an axially outwardly directed urging force to said front face, such that the retention ring is compressed.

According to a further preferred embodiment, the first locking surface, under the urging force of the spring means urges the retention ring against the second locking surface, thus securing the first coupling member retained inside the second coupling member.

According to a further preferred embodiment, the retention ring forms an electrically conducting path connecting the first coupling member and the second coupling member.

Advantageously, besides the additional conduction path realized via the spring, also the regular electrical conducting path between the coupling members via the retention ring is more securely connected, due to the urging force of the spring.

According to a further preferred embodiment, including a sealing ring positioned between the first and second coupling members, the sealing ring arranged such that as the retention ring becomes engaged between the first locking surface and the second locking surface, the sealing ring becomes engaged between the first coupling member, the second coupling member and a seal flange on the second coupling member.

According to a further preferred embodiment, the spring means exerts an axially outwardly directed urging force to said front face, such that the sealing ring is compressed between first coupling member, the second coupling member and a seal flange on the second coupling member, thus sealing the first coupling member against the second coupling member.

Advantageously, as relative movement of the coupling parts is prohibited or at least severely restricted, tear and wear of the sealing arrangement is reduced.

According to a further preferred embodiment, a release sleeve on the first coupling member sized to allow being pushed forward into the second coupling member to separate the first locking surface from the retention ring is provided.

According to a further preferred embodiment, an indicator ring is provided, positioned to provide an indication that the retention ring is positioned between the first locking surface and the second locking surface and that the release sleeve is positioned in its rearward in- active position, such that the first coupling member is secured to the second coupling member.

Advantageously, the indicator means is clearly readable, as the release sleeve is firmly secured in its position. As the play between the two coupling parts is taken up by the spring, the indicator means neither has any play and thus cannot cover the indicator means casual- iy-

The invention is now described with respect to an exemplary embodiment shown in the attached drawings. The exemplary description does not limit the scope of the invention in any way.

In the Figures,

Figure 1A shows a coupling arrangement according to the state of the art; Figure IB shows a Detail of Figure 1A in a magnified view;

Figure 2 shows an embodiment of the connection assembly according to the invention.

In Figure 1A, a coupling arrangement according to the state of the art is depicted in a sectional view. The coupling arrangement is shown in a section along its longitudinal axis A, the coupling assembly comprising first coupling member 1 extending along the axis A from a leading end 3 to a trailing end 4, having an exterior that includes a first locking surface 5 around the circumferential area and a front face 10 toward the front at the leading end 3. The first coupling member 1 may also be referred to as the male coupling member. A second or female coupling member 2 extends from a receiving end 6 to a remote end 7 and includes a receiving portion 8 sized to receive the first coupling member 1 inside. The second coupling member 2 includes a second locking surface 9 for cooperating with the first locking surface 5, and a flange face 11 delimiting the receiving portion 8 at the remote end 7 and facing the front face 10.

A retention ring 12 is positioned between the first and second coupling members 1, 2, the retention ring 12 being arranged such that as the first coupling member 1 is inserted into the second coupling member 2, the retention ring 12 becomes engaged between the first locking surface 5 on the first coupling member 1 and the second locking surface 9 on the second coupling member 2. This is also referred to as a snap-to-connect coupling, as the first coupling member 1 is thereby retained inside the second coupling member 2.

A coupling arrangement typically comprises a sealing arrangement, which is referred to here as a sealing ring 17 positioned between the first and second coupling members 1, 2. The sealing ring 17 is arranged such that as the retention ring 12 becomes engaged between the first locking surface 5 and the second locking surface 9, the sealing ring 17 becomes engaged between the first coupling member 1, the second coupling member 2 and a seal flange 20 on the second coupling member 2.

The coupling assembly further includes a release sleeve 18 on the first coupling member 1 sized to allow being pushed forward into the second coupling member 2 to separate the first locking surface 5 from the retention ring 12. An indicator ring 19 is provided to indicate that the retention ring 12 is positioned between the first locking surface 5 and the second locking surface 9 and that the release sleeve 18 is positioned in its rearward inactive position, such that the first coupling member 1 is secured to the second coupling member 2.

When the coupling assembly of Figure 1A is not pressurized, a relative motion of the coupling parts 1, 2 occurs due to a necessary clearance of the parts. Figure IB shows a detailed illustration of the region marked with the reference B in Figure 1A, where the retention ring 12 is engaged between the first locking surface 5 of the first coupling member 1 and the second locking surface 9 of the second coupling member 2, a gap, illustrated by the arrows C, has opened up between the retention ring 12 and the second locking surface 9. Therefore, the depicted current coupling design of a snap-to-connect coupling does not meet the requirement to provide a secure electrical conducting path between the two coupling parts 1, 2 at all working conditions. Further, the release sleeve 18 may cover the indication ring 19, which may lead to a false signalization of an unsafe connection, so that neither the indication requirement is fully met under all working conditions. The sealing arrangement 17 used to prevent leakage is subject to tear and wear, due to a relative move- ment of the two coupling parts 1, 2, which reduces the reliability of the connection.

Figure 2 shows an embodiment of the connection assembly according to the invention, which overcomes the shortcomings of the state of the art. A spring means 14 is located and compressed between the front face 10 and the flange face 11, wherein the spring means 14 preferably exerts an urging force to said front face 10 and the flange face 11, the force urging the first coupling member 1 in an axial direction along the axis A out of the second coupling member 2. The exerted urging force of the spring means 14 is an axially outwardly directed urging force. Due to the retention ring 12 engaged between the first locking surface 5 of the first coupling member 1 and the second locking surface 9 of the second cou- pling member 2, the coupling cannot be separated by the urging force but it is sufficient, to prevent the opening of a gap between the retention ring 12 and the first locking surface 5 or the second locking surface 9, thus advantageously providing a secure regular electric conducting path 16 from the first coupling member 1 to the second coupling member 2 via the retention ring 12.

As the first coupling member 1 and the second coupling member 2 are forced apart, even without being under pressure, the sealing ring 17 compressed between the first coupling member 1, the second coupling member 2 and a seal flange 20 on the second coupling member 2 undergoes less tear and wear by relative movement.

Further, the release sleeve 18 cannot slide over the indicator ring 19 accidentally, when moving together with the first coupling member 1, because the spring means 14 prevents the first coupling member 1 from entering deeper into the second coupling member 2.

The spring means 14 is preferably an annular wave spring, particularly made of electrically conducting material. Then the spring means 14 forms an additional electrically conducting path 15 connecting the first coupling member 1 and the second coupling member 2 via the spring means 14.

Bezugszeichenliste

1 First coupling member

2 Second coupling member

3 Leading end

4 Trailing end

5 First locking surface

6 Receiving end

7 Remote end

8 Receiving portion

9 Second locking surface

10 Front face

11 Flange face

12 Retention ring

14 Spring means, wave spring

15 Additional conducting path via the wave spring

16 Regular conducting path via the retention ring

17 Sealing ring

18 Release sleeve

19 Indicator ring

20 Seal flange

A Axis

B Detail