Pipe joints or couplings – With assembly means or feature – Particular tool-engaging means or with tool
Reexamination Certificate
1999-01-29
2001-02-13
Arola, Dave W. (Department: 3627)
Pipe joints or couplings
With assembly means or feature
Particular tool-engaging means or with tool
C285S081000, C285S308000, C285S321000, C285S330000, C285S906000
Reexamination Certificate
active
06186557
ABSTRACT:
This invention relates to a coupling assembly for pipelines having two connecting members, namely a male member and a female member which are connectable to and separable from each other, the male member having a spigot to be received in an opening in the female member for locking engagement therein by means of a radially deformable retaining element which is arranged in a recess in the female member's opening and is adapted to be urged into this recess by radial elastic deformation during the coupling operation, the spigot being provided with a recess into which the retaining element, due to elastic recovery, engages in the locked position of the connecting members so that the spigot is locked by the retaining element against being pulled out of the opening, and the rear side wall of the recess in the spigot, as seen looking in the coupling direction, being formed by an end surface of an unlocking element mounted on the spigot in an axially slidable arrangement. Further, the invention relates to a combination of such a coupling assembly and a release tool.
In a coupling assembly known from U.S. Pat. No. 5,570,910 A, the male member is integrally formed with the spigot, and the unlocking element is comprised of two sleeves, including an inner sleeve made of metal encompassing the spigot and an outer sleeve made of a plastic material encompassing the female member and engaging, in the unlocked position, with a locking bead in a groove in the female member. The inner metal sleeve is fully split to enable the sleeve to be expanded and mounted on the spigot. The outer sleeve made of plastic is not split but has an inward pointing sealing rib that engages on the male member to form a dust seal. The disadvantage of this known coupling assembly is the elaborate and expensive production of its unlocking element.
Furthermore, the split design of the inner sleeve means that producing an effective seal at the unlocking element, and particularly one that is also liquid-tight, is possible only with difficulty.
It is an object of the present invention to provide a coupling assembly of the type initially referred to that can be manufactured easily and economically and which enables by simple means a liquid-tight sealing of the coupling assembly's connecting zone.
This object is accomplished in accordance with the present invention in that the front side wall of the recess in the male member, as seen looking in the coupling direction, is formed by an annular support element which engages in a circumferential groove of the male member and is supported in axial direction inside the circumferential groove, and that the diameter of that section of the male member in front of the groove, as seen looking in the coupling direction, is the same size as, or smaller than, the smallest inner diameter of the unlocking element.
In the coupling assembly of the present invention the unlocking element can be a closed, rigid annular body adapted to be push-fitted onto the spigot prior to assembling the support element. Hence the unlocking element is easy to manufacture and can be sealed very effectively, for example, to liquid- or gastight standard, by simple means using, for example, an inner lying and an outer lying sealing ring. The coupling assembly of the present invention is also suitable, therefore, for explosion-protected applications. Considering that the unlocking element is mounted from the plug-in side of the spigot, the other end of the male member which is suitable for connection with a rigid or flexible pipeline can be of any desired configuration, being, for example, of an elbow or tee configuration.
A further advantageous possibility provided by the support element of the coupling assembly is the ability to choose different materials for the production of the male member and the production of the support element. The particular requirements needing to be met by the point of support cooperating with the retaining element can thus be met by a suitable choice of material, without this making the male member any more expensive. Thus, for example, it is possible to select a softer, easy-to-process material for the male member, while having the support element made of a harder material suitable for high seating stresses. With the coupling assembly of the present invention it is possible to design the shape of the force transmission surfaces between the support element and the male member relatively freely without it being tied to the shape of the support surfaces cooperating with the retaining element as defined by the locking and unlocking operation.
In an embodiment of the coupling assembly affording particular ease of manufacture, the annular support element as well as the retaining element is a split ring made of a spring material as, for example, spring steel or spring bronze, with a ring made of round wire of circular cross section being particularly suitable. This cross-sectional shape of the support element and retaining element results in favorable conditions for expanding the retaining element while connecting and releasing the coupling assembly. If the coupling assembly is intended for low compressive loads, the split ring can also be made of a plastic material. The round wire from which the retaining element and the support element are fabricated can have the same diameter. The diameters of the round wire cross sections for the retaining element and the support element, on the other hand, may differ. In accordance with a further proposal of the present invention, the support element may also be comprised of a closed ring connected with the spigot in a positive-engagement relationship by permanent radial deformation, for example, by curling a collar in a groove.
In order to secure the retaining element made of a ring of round wire by positive engagement when in the locked position, according to present invention the abutment surface provided on the female member for engagement of the retaining element can be a conical surface whose angle of taper is smaller than the angle between the tangent applied to the retaining element at the point of contact with the support element and the center axis of the coupling assembly. Consequently, the forces acting on the retaining element when the spigot is loaded in pulling direction strive to urge the retaining element radially inwardly against the spigot and axially against the abutment surface on the female member. Movement of the retaining element into the unlocked position is only possible, therefore, if the distance between the abutment surface on the female member and the support element of the spigot is increased a certain amount by urging the spigot into the receiving bore in the female member. This is opposed, however, by the load acting on the coupling assembly. It has proven advantageous for the angle of taper of the abutment surface to be 40° or smaller and for the angle between the tangent and the center axis to be 45° or greater. According to the present invention it is also possible to arrange for the seating surface on the spigot for engagement with the retaining element to have a slightly smaller diameter than the inner surface of the unlocking element which covers the seating surface when unlocking. This ensures that the deformations to the seating surface caused by the action of the retaining element under load do not impair the displaceability of the unlocking element.
The unlocking element is comprised preferably of a cylindrical or conical sleeve which can be axially movably arranged on the spigot or in the receiving bore of the female member and has a radial shoulder serving to introduce the force for moving the sleeve into the unlocked position. Furthermore, the unlocking element of the present invention can have a conical end with an angle of taper designed to promote the displacement of the retaining element into the recess of the female member by the unlocking element.
In the case of coupling assemblies for connecting a flexible pipeline it may be necessary to lock the spigot against rotation relative to the femal
Arent Fox Kintner & Plotkin & Kahn, PLLC
Arola Dave W.
Johannes Schafer Vorm. Stettiner Schrauben Werke GmbH & Co. KG
LandOfFree
Pipe connection and combination of a connection and a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pipe connection and combination of a connection and a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pipe connection and combination of a connection and a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2585353