Patent Description:
The present disclosure is in the field of restraining connections for locking pipe couplings.

There are documents disclosing devices with the purpose of blocking longitudinally cylindrical multi-material pipes, but these do not have independent restraining and sealing.

Furthermore, existing devices are not suitable to establish longitudinal connections between PVC or PE pipes of major diameters under high internal pressure. For example, in document <CIT> the structure of the valve has bolts, which compress the sealing member for both restraining and sealing. In document <CIT> the device is capable of independently sealing and restraining the pipes to be coupled, however it is suitable neither for large diameters under high internal pressures nor for when axial misalignments between the pipes coupled are present.

<CIT> discloses a pipe coupling including a pipe housing formed with an annular groove spaced axially from a first end of the pipe housing, a grooved coupling including a ring member that includes a coupling key received in the annular groove, and a grip ring assembly positioned at a second end of the pipe housing opposite to the first end. The grip ring assembly includes two clamp members arranged to be fastened and tightened towards each other by a fastener.

The invention is defined by the restraining pipe coupling for a pipe to be restrained, as defined in claim <NUM>.

The present subject-matter discloses a pipe coupling device that may be used for establishing longitudinally restrained connections of pipes of different diameters and/or multiple materials specially those of very large diameters under high internal pressure loads, all while allowing for a small axial misalignment between the pipes to be coupled.

The disclosure comprises a pipe coupling device suitable for connecting pipes. This structure can be a gate valve, a "T" socket, a socket bend, a fixation flange among others. The pipe coupling is preferably made of cast iron. The pipe coupling contains two axial ends, one of them is turned to the structure to be coupled to the pipe and the other end is turned to the pipe to be coupled.

The present document describes a device for:.

The device, according to an embodiment, comprises:.

The pipe coupling comprises a number of coupling sectors that are suitable to be tightened circumferentially between them with bolts and nuts using co-planar flaps to join the different sectors. These sectors that, according to an embodiment, are equal parts of a circle and, when the gaps between them are eliminated, make a full circle that allows a better tightening around the pipe.

Each coupling sector, according to an embodiment, contains in both its ends flaps with holes to allow the tightening between the sectors. These flaps contain a bolt housing to fix the head of the bolt and facilitate the tightening. These referred block bolts can be a metal plate that is placed between the head of the bolt and the flap of the sector. In an embodiment, said plate can be of cylinder shape to allow for misalignments between sectors.

Each sector's internal face, in contact with the sealing member, is comprised, according to an embodiment, of three non-concentric curvatures enabling for a better adaptation of the device to different pipe diameters to be coupled. Hence, restraining and sealing pressures are more evenly distributed along the surface of the pipe, independently of the pipe diameter.

The present disclosure includes a coupling device for connecting to a pipe wherein restraining and sealing are independently assured, the installation being simpler and easier.

It is disclosed a restraining pipe coupling for connecting to a pipe, comprising:.

The disclosed pipe coupling allows for shorter coupling arms, requiring shorter lengths, resulting in more compact pipe connections and pipe devices. The disclosed pipe coupling allows for an easier access to the fasteners for quicker and less encumbered work in location.

The disclosed pipe coupling also allows a degree of movement between restraining member and coupling sleeve such that small axial misalignments on the pipe can be tolerated while maintaining adequate grip and sealing. The restraining member is able to adjust by sliding along an annular abutment face on the coupling sector's surface. On the opposite side of the restraining member, it is facing a flexible spring-like element, absorbing such misalignment on the restraining member.

By having independent sealing and gripping elements, placed separately inside the coupling sector, sealing will not be affected by this potential adjustment of the restraining member.

In an embodiment, the circumferential sectors are arranged to receive nuts and bolts for fastening the circumferential sectors around the pipe wherein said bolts are aligned circumferentially.

The disclosed pipe coupling allows for the fasteners to be supplied independently of the coupling, such that eroded fasteners can be fully and easily replaced, not requiring machining or rethreading of the pipe coupling.

In an embodiment, the coupling sectors comprise perforated flaps arranged for receiving said nuts and bolts.

In an embodiment, the circumferential sectors comprise a surface arranged for compressing the sealing member against the pipe, comprised by three non-concentric radial surfaces.

The disclosure allows the same principle being applied on the recess that houses the semi-annular restraining member.

In an embodiment, each coupling sector comprises two flaps, each flap at an end of the respective circumferential sector, each of the flaps being coplanar with the contiguous flap of the neighbouring circumferential sector, for receiving said nuts and bolts.

In an embodiment, said one or more flaps comprise one or more bolt blockings for preventing a bolt or nut from rotating in order to facilitate the tightening of said nuts and bolts.

In an embodiment, the bolt blocking is a protruding rib in said one or more flaps.

According to the invention, each circumferential sector comprises a resilient element behind the semi-annular restraining member, arranged for allowing some tolerances on the restraining members so that small axial misalignments can be absorbed.

In an embodiment, the annular abutment surface on the coupling sector is comprised of a recess. On the coupling sleeve, said abutment surface is comprised of a tab which goes inside the recess on the coupling sector.

In an embodiment, the first annular abutment surface is comprised of a circumferential protruding rim on the coupling sleeve and the second annular abutment surfaces is comprised of a circumferential lip, on the coupling sector, having a circumferential recess for receiving said rim.

An embodiment comprises said nuts and bolts for fastening circumferentially around the pipe the coupling sectors.

In an embodiment, the coupling sleeve is of cast iron, in particular ductile cast iron.

In an embodiment, the coupling sector is of cast iron, in particular ductile cast iron.

In an embodiment, the restraining member is comprised of a main body in polymeric material, particularly POM, and a gripping element, placed within a recess on the restraining member.

In an embodiment, the gripping element is grooved, segmented, composed of multiple wedges or ridged for enhancing grip, preferably made of stainless steel.

In an embodiment, the seal ring is elastomeric, in particular polymeric, further in particular synthetic rubber, further in particular ethylene propylene diene monomer rubber, EPDM.

In an embodiment, the nuts and bolts are of stainless steel.

An embodiment comprises a removable stop tab inserted between two contiguous circumferential sectors of the restraining member for preventing said two contiguous circumferential sectors from clashing during transportation or mounting.

In an embodiment, the tab stop extends into a segment opening of the grip ring, such that grip ring is kept untightened in order to facilitate insertion of the pipe during mounting.

In an embodiment, said stop tab can be modular and partially removed. Given the diameters to be coupled, the operator knows beforehand the gap between the tabs on the coupling sectors. Hence, the tab stops left on the coupling device can be used to limit the torque applied on the bolts.

Furthermore, said stop tab can be made from a hard polymeric material, which enhances sealing behaviour on the pipe, in the interstitial spaces between tabs (existing on the coupling sectors).

An embodiment comprises a removable elastomeric element between first and second annular abutment surfaces for preventing the first and second annular abutment surfaces from clashing during transportation or mounting.

An embodiment comprises a partially removable elastomeric element between the restraining set tab surfaces for compressing the sealing member and enhancing sealing between the restraining sets or the coupling sectors.

In an embodiment the semi-annular restraining member set and the recess of the coupling sector for receiving the semi-annular restraining member set have a conical shape arranged to strengthen the gripping of the grip member through an axial pipe traction effort result.

In an embodiment, the sleeve comprises a rail arranged to guide the linear movement of the coupling sector.

The pipe coupling sleeve comprises a tab which goes inside a first recess existing on the coupling sector. Said tab has an extruding face for guiding the coupling sector's radial (linear) movement. Said coupling sector has a second recess which comprises an annular abutment surface against which the restraining members are compressed when they are gripping on the pipe. Said restraining members comprise circular recesses on which are assembled the gripping elements. Furthermore, on the inside of the tabs, on the coupling sectors, there are slots along which said pins can move. Said pins are assembled on those restraining members positioned on the far ends (left or right, facing the front of the coupling sector) of the semi-annular restraining member, which is assembled inside the coupling sector. Behind the semi-annular restraining member exists a spring-like annular element for compressing the semi-annular restraining member against the annular abutment surface on the coupling sector and, because this follows a wedge principle, compresses the semi-annular restraining member against the pipe, locking it axially. Keeping the central restraining members that form the semi-annular restraining member set in place, a spring is inserted through a hole that exists in all of the restraining members.

The coupling sleeve contains a seal groove or recess to place a lip seal ring, this lip seal ring prevents leakage.

The disclosure belongs to the field of restraining connections for pipe couplings and may be applied in structures for laying and blocking pipes with a circular cross section. The pipe coupling of the present disclosure may be used to establish longitudinally force-locked connections with PVC or PE pipes.

The following figures provide preferred embodiments for illustrating the description and should not be seen as limiting the scope of invention.

The present disclosure belongs to the field of restraining connections for pipe couplings. The present subject-matter discloses a pipe coupling to be applied in structures for laying and blocking pipes with a circular cross section. In particular, the pipe coupling of the present disclosure may be used to establish longitudinally force-locked connections with PVC or PE pipes.

The restraining pipe coupling for a pipe to be restrained, comprises a coupling sleeve for receiving an end of the pipe and comprising a coupling sleeve tab which protrudes radially and has an annular abutment surface; a sealing ring for sealing between the annular abutment surface of the coupling sleeve and the pipe; a plurality of coupling sectors which are shaped as circumferential annular sectors and radially displaceable towards the pipe by circumferentially tightening between consecutive coupling sectors.

<FIG> illustrates an embodiment according to the present disclosure of a pipe coupling that comprises: pipe coupling device <NUM>; pipe to be coupled <NUM>; coupling sectors <NUM>; restraining member <NUM> forming the semi-annular restraining member <NUM>.

<FIG> illustrates in more detail an embodiment according to the present disclosure of a pipe coupling that comprises: pipe coupling device <NUM>; pipe to be coupled <NUM>; sealing member <NUM>; coupling sleeve <NUM>; coupling sectors <NUM>; restraining member <NUM>; gripping member <NUM>; spring-like element <NUM>;.

<FIG> illustrates a detail of the coupling sector <NUM> with the annular restraining member and spring-like element.

The present disclosure also relates to a pipe coupling <NUM> comprising a number of separable sectors <NUM> wherein each sector has two flaps <NUM>. The flaps <NUM> of different sectors <NUM> are co-planar between them and their tightness is ensured by bolts and nuts. These flaps contain in the external face a cylindrical recess <NUM> to insert a cylindrical washer in order to absorb misalignments between coupling sectors <NUM>.

In an embodiment, the coupling sleeve <NUM> comprises a tab <NUM> for housing/abutting the sealing member <NUM> in order to prevent leakage.

<FIG> illustrates in more detail an embodiment according to the present disclosure of a pipe-coupling device. In this figure, one can see a cutaway view of the coupling sector <NUM>; the semi-annular restraining member <NUM> formed by the succession of several restraining members <NUM> and the spring-like, resilient, element <NUM> all housed in a recess <NUM> present on the coupling sector.

In an embodiment, a stop tab is included between two contiguous coupling sectors <NUM> of the restraining member such that these do not clash during transportation or mounting. The stop tab can be modular and partially removed so that length of the stop tab remaining corresponds to the interstitial space between coupling sectors. Said stop tab limits the approximation between coupling sectors <NUM> and also helps compressing the sealing member on the interstitial space between coupling sectors <NUM>, enhancing sealing behaviour on a defective area.

Claim 1:
A restraining pipe coupling for a pipe to be restrained, comprising:
a coupling sleeve (<NUM>) for receiving an end of the pipe and comprising a coupling sleeve tab (<NUM>) which protrudes radially and has an annular abutment surface;
a sealing ring (<NUM>) for sealing between the annular abutment surface of the coupling sleeve (<NUM>) and the pipe (<NUM>);
a plurality of coupling sectors (<NUM>, <NUM>) which are shaped as circumferential annular sectors and radially displaceable towards the pipe by circumferentially tightening between consecutive coupling sectors;
a plurality of restraining members (<NUM>, <NUM>, <NUM>, <NUM>), each restraining member being formed by a plurality of restraining member elements (<NUM>, <NUM>, <NUM>, <NUM>) comprising a gripping surface for restraining the pipe from being pulled from the coupling;
wherein each of the coupling sectors (<NUM>, <NUM>) comprises a first recess (<NUM>) arranged towards the pipe for slidably receiving the coupling sleeve tab (<NUM>) and the sealing ring (<NUM>);
each of the coupling sectors (<NUM>, <NUM>) comprises a second recess arranged towards the pipe for receiving one or more restraining members;
each restraining member element (<NUM>, <NUM>, <NUM>, <NUM>) is wedge-shaped by comprising a surface which is inclined towards a longitudinal central axis of the pipe, such that the inclined surfaces of the coupling restraining member elements form a combined frustoconical restraining surface which tapers radially inwards away from the coupling sleeve; and
the second recess comprises an inclined recess surface, such that the inclined recess surfaces of the coupling sectors (<NUM>, <NUM>, <NUM>, <NUM>) form a combined frustoconical abutment surface for facing against the combined frustoconical restraining surface;
wherein when the coupling sectors (<NUM>, <NUM>, <NUM>, <NUM>) are radially displaced towards the pipe by circumferentially tightening between consecutive coupling sectors, the sealing ring (<NUM>) is compressed against the pipe and the annular abutment surface of the coupling sleeve; and when the pipe is pulled from the coupling, the restraining member elements, by the mutual sliding of the frustoconical surfaces,
are tightened together and against the pipe,
characterised in that
each circumferential sector comprises a spring-like element (<NUM>) behind a semi-annular restraining member, arranged for allowing some tolerances on the restraining members so that small axial misalignments can be absorbed.