The invention relates to a hydraulic quick connector comprising :

- a coupling sleeve having a coupling end and an opposite connection end for connection with a fluid line;

- a nipple having an insertion end and a connection end for connection with a fluid line, which nipple is

insertable with the insertion end into the coupling sleeve at the coupling end;

- a releasable lock for blocking the nipple in an inserted position, wherein the nipple is inserted into the coupling sleeve.

Hydraulic quick connectors are widely known and used for connecting hydraulic lines, which also require to be disconnected. Typically such quick connectors have a

releasable lock with an axially movable operating sleeve, which allows or blocks balls arranged in the coupling sleeve, which balls also protrude in a groove of the nipple, such that the nipple can be locked in the coupling sleeve and can be released by moving the operating sleeve allowing the balls to move out of the groove in the nipple and allowing the nipple to be retracted from the coupling sleeve. However other releasable locks are also known for hydraulic quick

connectors.

For certain applications it is required that the hydraulic lines are hydraulically connected but also

electrically connected, for example in automotive

applications. With typical hydraulic quick connectors, rubber seals are used between the coupling sleeve and the nipple to provide a leak tight connection, but this also results in that it is not ensured that a reliable electric connection is provided . Other connectors are known for connection hydraulic lines, but such connectors are not releasable. For example US 2017040717 and DE 102005013981 describe such a quick connector for quickly connecting hydraulic lines. The quick connectors do not comprise a releasable lock, so after inserting a nipple into the coupling sleeve, the connection is permanent. The above mentioned prior art does use an electric contact ring to ensure an electric contact between the nipple and the coupling sleeve and therewith to ensure electric contact between connected hydraulic lines.

None of the electric contact rings are suitable for a releasable connection. The ring of DE 102005013981 locks into a groove after insertion, preventing retraction of the nipple, whereas the electric contact ring of US 2017040717 has a complex structure and requires a number of ribs and grooves in the connection sleeve. When a known hydraulic quick

connector is to be adapted for an electric contact ring as known in US 2017040717, a substantial redesign is required of the hydraulic quick connector, which is typically undesired.

Therefore, it is an object of the invention to reduce or even remove the above mentioned disadvantages.

This object is achieved according to the invention with a hydraulic quick connector according to the preamble, which connector is characterized by an electric contact ring for ensuring electrical contact between the coupling sleeve and the nipple in the inserted position, which contact ring is mounted on a cylindrical mounting surface, which cylindrical mounting surface is arranged either concentrically on the nipple or in the coupling sleeve, wherein the electrical contact ring is bound by two spaced apart axial end planes, wherein the electrical contact ring contacts the mounting surface at least at both axial planes and wherein the

electrical contact ring is spaced apart from the mounting surface at least in an axial middle plane positioned between both axial end planes.

The electrical contact ring of the invention has a curved contact surface for the other part. When the ring is arranged on the nipple, the contact surface of the ring is shaped as the radially outer part of a torus while when the ring is arranged in the coupling sleeve, the ring is shaped as the radially inner part of a torus.

By having the electrical contact ring contacting the mounting surface at least at both axial planes and having the electrical contact ring spaced apart from the mounting surface at least in an axial middle plane, it is ensured that the nipple can be inserted and retracted from the coupling sleeve without the electrical contact ring blocking or limiting said movement.

Also the partial torus shape of the ring ensures that the ring can be compressed at least somewhat to ensure a contact force and accordingly good contact between both the nipple and the coupling sleeve.

In a preferred embodiment of the hydraulic quick connector according to the invention the body of the

electrical contact ring extends between the two end planes and wherein the body is provided with slits extending in axial direction from either end plane and in circumferential

direction alternatingly from one and the other end plane, such that the body has a meandering pattern.

Due to the slits providing a meandering pattern to the body the electrical contact ring is provided with an increased resiliency which enhances the contact between the nipple and the coupling sleeve.

In another embodiment of the hydraulic quick

connector according to the invention the electrical contact ring comprises at least one lip extending in one of the end planes and into the mounting surface to secure the electrical contact ring in position.

In a further preferred embodiment of the hydraulic quick connector according to the invention the cylindrical mounting surface is provided by the bottom of a groove

arranged either in the nipple or in the coupling sleeve.

A groove provides space for the electric contact ring and a groove is easily provided in a known nipple or coupling sleeve of a prior art hydraulic quick connector. This allows for easy adaptation of a known quick connector to integrate the invention and have a reliable electric

connection between the nipple and the coupling sleeve. The groove further ensures that the ring is not shifted from its position, as both edges of the ring will contact the mounting surface and will therefore be physically bound by the walls of the groove.

In still a further embodiment of the hydraulic quick connector according to the invention the electrical contact ring is of a beryllium copper alloy. Beryllium copper combines high strength with non-magnetic and non-sparking qualities. It has excellent metalworking, forming and machining properties. Therefore, it is very suitable for an electric contact ring for the invention.

Yet another preferred embodiment of the hydraulic quick connector according to the invention further comprises a seal arranged in the mounting sleeve, wherein the electric contact ring is mounted in the mounting sleeve at a position seen in insertion direction of the nipple beyond the seal.

Having the contact ring mounted at a position seen in insertion direction beyond the seal ensures that any scratches caused by the contact ring on the nipple outer surface will not influence the sealing surface and ensure a reliable sealing even after numerous disconnects and connects of the hydraulic quick connector.

Preferably, the nipple is provided near the insertion end with a first circumferential surface part having a reduced diameter and a second circumferential surface having a larger diameter with respect to the first circumferential surface part, wherein the seal abuts the second

circumferential surface part when the nipple is inserted into the mounting sleeve.

The first surface part with reduced diameter allows for an easy insertion of the nipple and minimizes the chance that the leading edge of the nipple can damage the seal.

These and other features of the invention will be elucidated in conjunction with the accompanying drawings.

Figure 1 shows a perspective view with cut away portions of a prior art hydraulic quick connector.

Figure 2 shows a first embodiment of the invention.

Figure 3 shows a second embodiment of the invention.

Figures 4A and 4B show a cross section of respectively the first and second embodiment.

Figures 5A and 5B show a perspective view of the electric contact ring of respectively the first and second embodiment .

Figure 6 shows a perspective view with cut away portions of a third embodiment of the invention.

Figure 1 shows a perspective view of a prior art hydraulic quick connector having a nipple 1 and a coupling sleeve 2. The nipple 1 has an insertion end 3 and a connection end 4 for connection with a fluid line. The connection can for example be embodied as a shrink fit or with a thread. The nipple 1 has furthermore a flange 5, with which the nipple 1 can be locked into the coupling sleeve 2.

The coupling sleeve 2 has also a connection end 6 for connection with a fluid line. Opposite of the connection end 6 is arranged the coupling end 7. Balls 8 protrude into this coupling end 7, such that after insertion of the

insertion end 3 the balls 8 will lock behind the flange 5. The operating sleeve 9, which is slidable over the coupling sleeve 2 prevents the balls 8 from moving out of engagement with the flange 5, until the operating sleeve 9 is slid against the force of the spring 10. Furthermore, a seal 11 is arranged in the coupling sleeve 2 to ensure a leakproof connection.

Figure 2 shows a first embodiment 20 according to the invention. This embodiment 20 corresponds largely with hydraulic quick connector 1, 2 shown in figure 1. An electric contact ring 21 is provided in a groove 22 on the insertion end 3 of the nipple 1. This electric contact ring 21 ensures contact between the nipple 1 and the coupling sleeve 2.

Figure 4A shows a cross section of the nipple insertion end 3 provided with the groove 22 and the electric contact ring 21. The bottom of the groove 22 provides a cylindrical mounting surface on which the electric contact ring 21 is arranged. The ring 22 is bound by two axial end planes 23, 24. The ring 22 contacts at said axial end planes 23, 24 the mounting surface, while in a middle plane 25 the ring 22 is spaced apart from the bottom of the groove 22.

As shown in figure 5A, the electric contact ring 21 is provided with slits 26, 27 extending respectively from the axial end plane 23 and the axial end plane 24, such that the body of the electric contact ring 21 has a meandering pattern. This meandering pattern provides additional resiliency such that when the nipple 1 is inserted into the coupling sleeve 2 the part of the ring 21 at the middle plane 25 is pressed against the inside of the coupling sleeve 2.

Figure 3 shows a second embodiment 30 according to the invention. In this second embodiment 30 an electrical contact ring 31 is arranged in a groove 32 in the coupling end 7 of the coupling sleeve 2.

Similar to the first embodiment 20 and shown in figure 4B, the electrical contact ring 31 is arranged on the mounting surface provided by the bottom of the groove 32. At the axial end planes 33, 34 the ring 31 is in contact with the bottom of the groove 32, while at a middle plane 35 the ring 31 is spaced apart from the bottom of the groove 32 to contact the nipple 1 when inserted into the coupling sleeve 2.

Figure 5B shows the electrical contact ring 31 in perspective view. Similar to the ring 21 shown in figure 5A, the ring 31 is provided with slits 36, 37 extending

respectively from the axial end plane 33 and the axial end plane 34.

The electrical contact ring 31 is provided with lips 38, which extend into the bottom of the groove 32 to secure the ring 31 into position.

Figure 6 shows a perspective view with cut away portions of a third embodiment 40 of the invention. The hydraulic quick connector 40 is shown in connected position, wherein the nipple 41 is inserted into the coupling sleeve 42 in the direction I.

The coupling sleeve 42 is provided, when seen in insertion direction I first with a seal 43 and there beyond with an electric contact ring 44, similar to the embodiment shown in figures 5A and 5B.

The nipple 42 is provided with a first

circumferential surface part 45 having a reduced diameter compared to the second circumferential surface part 46, which is used a sealing surface for the seal 43. As the first circumferential surface part 45 has a reduced diameter, this surface part is easily moved beyond the seal 43 without any dammage . And because the electric contact ring 44 is mounted in the coupling sleeve 41 beyond the seal 43, when seen in insertion direction I, any scratches caused by the electric contact ring 44 on the second circumferential surface part 46 will not influence the sealing characteristics of the seal 43 on the second circumferential surface part 46.