GB2430015A - Branch connector retained by hooked arms - Google Patents

Abstract

A branch pipe connector 10 comprises a hollow cylindrical spigot body 4a having gripping arms 4b which can be inserted through a hole 3a in the wall of a main pipe 3. A locking member 1, (1e, figure 3) is mounted coaxially with the spigot and moves axially to cooperate with lugs 4e on the gripping arms, holding them radially outwards and preventing them from moving to an unlocked position. Tightening means, which may comprise a threaded member 5, is provided to urge the locking member into the locked position. The gripping arms 4d may have a hooked shape 4c, to engage the inner surface of the main pipe 3, and the locking member 1 may, in use, contact the outer surface of the pipe 3 and seal against it.

Description

- 2430015

PIPE CONNECTOR

This invention relates to a pipe connector for attaching a second pipe to a first pipe, in particular where the first pipe is a main pipe and the second pipe is a branch pipe.

In pipe systems for transporting fluid and/or gas it is common for branching to occur, i.e. where one or more pipes branch off from the side of a main pipe.

This is often necessary where the contents of the pipe have to be transported to multiple locations or when it is required to drain the main pipe of, e.g., condensation.

Branch connections are created by cutting an appropriately sized hole in the main pipe and fitting the branch pipe into this hole. It is of course important to ensure a secure connection between the main and branch pipes in order to prevent leaking or detachment. This can be achieved by welding the branch pipe to the main pipe, although this is only suitable for certain materials and requires the use of skilled personnel and specialised equipment.

Alternatively a pipe connector can be used. This component is designed to be attached at one end to the main pipe and at the other to the branch pipe. One such pipe connector is described in GB1269499. Here, the pipe connector comprises a saddle member, spigot member and a socket member. The spigot member is an internally threaded ring or sleeve having hook shaped arms projecting from one end. These can be bent or deflected radially inwardly to allow the spigot member to be forced into the main pipe, after which the arms return to their original shape, causing the hook ends to engage the inside of the pipe. The saddle member forms a seal around the hole on the exterior of the pipe and houses the spigot member.

In order to ensure a firm connection and to prevent the spigot arms from bending to allow the spigot member to disconnect from the pipe, a socket member is threadedly inserted into the spigot member such that it lies along the entire inner length of the spigot member and abuts the saddle member. By rotating the socket member the spigot member can be drawn against the internal wall of the main pipe and the saddle member pushed against the pipets outer wall. In addition as the socket member lies along the length of the spigot arms this prevents their inward deflection. A branch pipe can then be connected to the other end of the socket member using appropriate sealing means.

Therefore, this apparatus provides a way of creating a secure connection between main and branch pipes without the need for welding.

However, there are a number of disadvantages with this device. Firstly, as the socket member must be inserted into the spigot member this reduces the cross sectional area of the flow path through the connector.

This places restrictions on the thickness of the socket member and hence the materials which can be used to create a suitable socket member of sufficient strength.

The length of the socket member is also dictated by the spigot member, as the socket member must cover the length of the spigot arms in order to prevent unwanted deflection of these arms once the spigot has been connected to the pipe. This means that, when assembled, the socket member completely overlaps the spigot arms.

In order to attach or remove the connector from the main pipe therefore, the socket member must be unscrewed from the spigot member to allow the arms to distort. This action is time consuming and often, given the narrow length of the spigot body, will result in the socket being completely removed from the spigot. This disassembly of the connector can result in components becoming lost or damaged.

Further, as the socket member acts both as a tightening means to firmly fasten the connector to the main pipe and also as a socket for the branch pipe, once the system has been assembled it is difficult to adjust or retighten the connection to the main pipe as this requires rotation of the socket member, a task that would be difficult if not impossible when this has been attached to the branch pipe.

There therefore exists a need to create a pipe connector which can easily be attached to, adjusted and removed from a main pipe without requiring disassembly of the connector.

According to the present invention there is provided a pipe connector for connecting a branch pipe to a main pipe, the main pipe having a hole in its wall, the connector comprising; a spigot member comprising a hollow cylindrical body and gripping arms extending in the axial direction, the gripping arms being moveable between a first position, in which the arms can be inserted and removed from the hole in the main pipe, and a second position, in which the arms cannot be inserted or removed from this hole, the gripping arms comprising an abutment surface for abutment with an inner wall of the main pipe when the gripping arms are in the second position and a lug; a locking member comprising a hollow cylindrical body coaxial with the spigot member and lug engagement surfaces for substantially preventing the movement of the lug towards the first position; and a tightening means for fixing the connector to the main pipe by axial movement of the locking member relative to the spigot member so as to at least partially align the lugs and lug engagement surfaces to prevent the movement of the gripping arms into the first position.

The inventors of the present invention have realised that it is only necessary to prevent movement of the gripping arms into the first position over a narrow axial range, i.e. that in which the abutment surface could conceivably be in contact with the inner wall of the main pipe. By providing lugs on the gripping arms, it is possible to only prevent movement of the gripping arms over an axial length which is less then the axial length of the gripping arms, e.g. only over the narrow axial range mentioned above. This means that less adjustment of the device is required in order to allow movement into the first position (unlocking movement) to occur to occur, and thus to enable attachment to or removal from a main pipe. This prevents the need to partially or completely disassemble the components of the connector, and hence reduces the possibility of these parts becoming lost or damaged, as the locking member and spigot member can remain in overlapping contact throughout the procedure.

Preferably therefore the axial displacement necessary to bring the lugs into or out of at least partial alignment with the lug engagement surfaces is less than the axial length of the gripping arms.

The axial range over which unlocking movement of the gripping arms must be prevented is dependent on the range of thicknesses of pipe which may be encountered.

The length of the lug or lug engagement surface can be chosen by the skilled man based on his knowledge of the pipes with which the connector is intended to be used.

The term lug should be interpreted broadly to mean any change in the profile of the gripping arm which creates one area of the arm which can engage the lug engaging surfaces to prevent movement of the gripping arm into the first position and another area of the arm which cannot. For example, the lug can be formed by creating a recess along part of the length of the gripping arm, the unrecessed area acting as a lug to prevent unlocking movement of the arm. However, preferably the lug is a protrusion.

Each lug may have a shoulder at the end closest to the hollow cylindrical body of the spigot member, unlocking movement of the gripping arms being possible when the lug engagement surface is moved beyond the shoulder in the direction of the spigot body.

Preferably this shoulder is located closer to the distal end of the gripping arms than the attachment end of the gripping arms (i.e. where the arms are attached to the spigot body) When the lug engagement surface is at least partially aligned with the lug it is not possible for the gripping arms to be moved into the first position, as movement in this direction results in the lug contacting the lug engagement surface (if the alignment of these two components has not already resulted in such contact) The spigot member may comprise any number of gripping arms, however two opposing arms are preferred as this provides a secure fastening while minimising the size (and hence production cost) of this element. This is particularly preferred when the gripping arms are located in the flow path through the connector as this results in minimal reduction to the cross sectional area of the flow path.

In addition, this configuration of gripping arms allows the connector to be attached to the main pipe in such a way that both gripping arms are positioned along the centre line of the pipe. This minimises disruption to the flow through the main pipe.

In order to assist the user in correctly positioning the gripping arms along the centre line of the pipe, it is preferable for the connector to comprise a marker visible on the exterior of the connector adapted to indicate the orientation of the gripping arms. This enables the user to correctly position the gripping arms along the centre line of the pipe.

In preferred embodiments, the marker is raised from the surface of the connector and runs parallel to the gripping arms. This allows the marker to be distinguished by both sight and touch. Alternatively the marker could be distinguished through colour. The marker is preferably in the same plane as the two opposing gripping arms so that the user can simply line these up on the centre line of the pipe in order to correctly position the gripping arms. Preferably the marker is in the form of a line or lines.

When a number of gripping arms are used it is not necessary for all of these to comprise a lug. It has been found that two opposing lugs in combination with associated lug engagement surfaces provide the required security in the connection.

The abutment surface could be adapted simply to provide a frictional engagement with the hole walls. As these walls do not form part of the exterior of the main pipe these are considered to be inner walls. For example, the gripping arms could be coated with a layer of rubber or foam material that is forced against the hole walls when the gripping means are moved into the second position. However, it is preferred that the abutment surface abuts against the internal circumference of the main pipe to increase the strength of the attachment.

The abutment surface can be provided, for example, by a groove at the distal end of the gripping arm which is greater than or equal to the thickness of the main pipe with which the connector is intended for use.

However, preferably the abutment surface is formed by a radially outwardly extending protrusion, such as a wedge or hook. This negates the need to take the thickness of the pipe into consideration when manufacturing the iS connector.

Preferably the gripping arms are deflectable (or distortable) between first and second positions. This prevents the need for hinges etc which would increase the complexity of the device and may break during the life of the connector. Preferably the first position is the deflected position and the second position is the non deflected position. In this way the resilience of the gripping arm is employed to increase the strength of the connection to the pipe.

Preferably the gripping arms extend through the locking member. In this way the gripping arms are protected by the locking member. In such embodiments the lug engagement surfaces project from the inner wall of the locking means. In one preferred embodiment the lug engagement surfaces comprise ring or D-shaped projections which encircle the gripping arms. In this way the lug engagement surfaces also help to guide and support the gripping arms.

In preferred embodiments the locking member is positioned circumferentially about at least part of the spigot member, with inwardly extending portions which slidingly receive the gripping arms. The lug engagement surfaces are outwardly facing surfaces provided on the inwardly extending portions. Preferably such inwardly extending portions and the lug engagement surfaces are positioned close to or substantially at the end of the locking member which is closest in use to the main pipe.

The tightening means can operate either by moving the spigot member or the locking member such that these elements are moved relative to one another to bring the lugs and lug engagement surfaces into at least partial alignment. Preferably however the tightening means acts to alter the axial position of the spigot member as in this way the tightening means can also act draw the abutment surface against the inner wall of the main pipe and thus improve the connection between the connector and the main pipe. This also allows the axial position of the locking means to remain fixed during the attachment of the connector to the pipe and therefore this can be firmly placed and held against the exterior of the pipe during fitting.

The tightening means can be formed from the spigot and locking members themselves, e.g. using a ratchet or spring loaded detents. However, it is preferable that the tightening means comprises an additional component.

Preferably this component is threadedly engaged with either the spigot member or the locking member. A threaded engagement is particularly preferred when the tightening means acts on the spigot, as this allows the abutment surface to be very tightly drawn and held against the inner wall of the pipe.

Therefore, in one embodiment the tightening means comprises a nut in threaded engagement with the spigot member. It is preferred that the tightening nut is located on the exterior of the spigot. In this way this component does not interfere with the flow path.

Therefore, the connector provides a further improvement in that the tightening means does not need to be located within the flow path of the connector.

Instead only the relatively small gripping arms and lug engagement surfaces are found within the flow path.

This reduces the restrictions placed on the width and materials used for the tightening means as this no longer has any effect on the cross sectional area of the flow path.

This is considered inventive in its own right and therefore, viewed from a further aspect the present invention provides a pipe connector for connecting a branch pipe to a main pipe, the connector comprising; a spigot member for connection to the main pipe, the spigot member comprising a flow path and gripping means, the gripping means being moveable between a first position and a second position, wherein in the first position the gripping means can be inserted into and removed from the main pipe and in the second position the gripping means cannot be inserted into or removed from the main pipe; a locking means comprising locking portions which are capable of locking the gripping means in the second position when the locking portions are correctly aligned with the gripping means; and an activating means for positioning the locking portions in correct alignment with the gripping means; wherein the activating means is located outside of the flow path.

Preferably the locking means is also located substantially outside the flow path. For example, as - 10 - discussed above only the lug engagement surfaces could be located in the flow path with the main body of the locking means at least partially housing the spigot member.

Preferably, when the lug and lug engagement surfaces are in at least partial alignment the tightening nut is in communication with pipe surface.

In this way, as well as pulling the abutment means against the inner wall of the main pipe, tightening of the nut also pushes the connector into the outer wall of the pipe. The communication between the pipe and the nut can be through direct contact but is preferably through indirect contact, i.e. via another component of the connector.

Preferably the locking member is adapted to directly contact the outer surface of the main pipe.

This allows the lug engagement surfaces to be located close to the distal ends of the gripping arms when in a locked position. This reduces the stress placed on the gripping arms at the lug location and therefore reduces the risk of breakage or unwanted distortion of the gripping arms.

Preferably the locking member comprises a seal at the end adapted for contact with the main pipe. This helps to ensure the connection is air and/or fluid tight. A variety of seals can be provided to enable the connector to be used with pipes of differing diameters.

Once these have been fitted to the locking member however they are considered to form part of this member and therefore contact between the pipe and seal is considered to be direct contact between the locking member and the pipe.

Preferably the connection for the branch pipe is provided by an additional component of the connector.

- ii - In this way the connection to the main pipe can be adjusted/ checked without the need to remove the branch pipe. Preferably an end cap capable of attachment to a branch pipe is provided in threaded engagement with the spigot means.

A preferred embodiment will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG 1 shows an exploded view of a pipe connector according to a preferred embodiment of the present invention; FIG 2 shows the assembled pipe connector of FIG 1 attached to a main pipe; and FIG 3 shows a cross section along line A-A of FIG 2.

Pipe connector 10 comprises four main components and a number of sealing elements. It is designed to simply and securely connect a branch pipe to a main pipe 3 via hole 3a created using known techniques.

Locking member 1 is a hollow cylindrical member with an annular groove la at one end and flange lb extending radially outwards from the opposite end.

Groove la houses seal 2, which is shaped to follow the curvature of pipe 3 and thus create a water tight join between the connector 10 and pipe 3. Flange lb is strengthened by ridges ic which extend along the length of locking member 1. These ridges ic also act as a positioning marker when the connector is being attached to the main pipe, as will be explained below.

Protruding from flange lb in the axial direction are guide arms ld. When the connector 10 is assembled these arms ld fit within corresponding channels 4d in spigot member 4, in order to ensure the correct alignment of these elements. This results in gripping arms 4b being - 12- aligned with ridges ic. When the connector is assembled (see FIG 2) the gripping arms 4b are not visible.

However, their position is known through the location of ridges ic. This allows the gripping arms 4b to be attached to the main pipe along its central line.

Spigot member 4 is a hollow cylindrical body 4a from which gripping arms 4b protrude in the axial direction. Each gripping arm 4b has at its distal end hook 4c, which curves radially outwards from and back along arm 4b. The ends of hooks 4c are blunt and form an abutment surface 4f. Spigot member 4 is designed such that the distance between the radially outer surfaces of arms 4b is equal to or less than the diameter of hole 3a whereas the distance between abutment surfaces 4f has a greater diameter than hole 3a. Under pressure arms 4b can be bent, or deflected, radially inwards, thus allowing the hooks 4c to enter hole 3a. However, once the pressure is removed the natural resilience of the arms 4b means that these return to their original, non deflected, position.

Gripping arms 4b also comprise a radially inwardly projecting lug 4e.

Spigot body 4a has three distinct sections, each having a different outer radius. First section 41 has a radius of less than that of the internal surface of locking member 1, thus allowing this section of spigot member 4 to be inserted into the locking member 1.

First section 41 also contains an annular groove 41a into which 0 Ring 8 is inserted to provide a seal between guide member 1 and spigot 4.

Second section 42 has a outer radius of greater than the internal radius of guide member 1. This therefore limits the extend to which spigot 4 can be inserted into guide member 1, as second section 42 will - 13 - abut against flange ib, preventing any further insertion. Second section 42 is externally threaded, however these threads are broken at intervals to provide guide channels 4d. These guide channels 4d act with the guide arms id to ensure than spigot 4 is inserted into the guide member 1 at the correct orientation to ensure that gripping arms 4b are aligned with lug engagement surfaces le (see FIG 3) and ridges ic.

Third section 43 has an outer radius greater than that of first section 41 but less than that of second section 42. It is also threaded about its external circumference, although not along its entire length.

Tightening nut 5 is a hollow cylindrical member, a section of the inner wall of which is threaded for engagement with the external thread of second section 42 of spigot member 4. The outer radius of tightening member 5 is equal to that of flange lb which thus limits its axial movement.

Finally, end cap 6 is a further hollow cylinder with a smaller diameter than tightening member 5. The interior wall is threaded along part of its length for engagement with the thread of third section 43 of spigot member 4. End seal 7 is positioned radially between third section 43 and end cap 6 in the non threaded section. This seal provides a seal between connector 10 and a branch pipe, which is inserted into the connector through end cap 6.

Once assembled, the connector 10 appears as shown in FIG 2. The spigot member 4 is concealed within the connector 10, therefore protecting the threaded parts and gripping arms 4b from damage.

In order to attach the connector 10 to pipe 3 first the tightening nut is rotated anti-clockwise such that the tightening nut moves axially back along spigot means - 14 - 4 until the front end of second section 42 is exposed.

Spigot 4 can then be pushed through locking member 1 until second section 42 abuts against flange lb. Gripping arms 4b are pushed through locking member 1 to the extent that lugs 4e clear the lug engagement surfaces le.

Gripping arms 4b are then inserted into hole 3a.

The pressure on the arms 4b forces them to distort, allowing hooks 4c to enter the hole 3a. The arms 4b are further inserted into pipe 3 until seal 2 encloses hole 3a. The connector 10 can then be rotated to align ridges ic with the centre line of pipe 3. As the ridges ic are in the same plane as gripping arms 4b, these are also aligned with the centre line, thus minimising the disturbance caused to the flow through pipe 3.

Tightening member 5 is then rotated clockwise until it abuts support flange lb. When the tightening nut is further rotated, spigot 4 is moved axially backward, drawing arms 4b out of pipe 3. This continues until the abutment surfaces 4f of hooks 4c contact the inner wall of pipe 3. During the tightening of tightening nut 5, lugs 4e are moved back into alignment with lug engagement surfaces le. Distortion of the arms 4b is thereby prevented as lugs 4e are prevented from moving radially inwards by the lug engagement surfaces le against which they abut. It should be noted that partial alignment of the two surfaces is sufficient to prevent distortion or deflection of the gripping arms 4b and it is not necessary that the surfaces should completely overlap.

Therefore, the arms 4b are maintained in the non distorted position, which prevents hooks 4c from leaving the pipe 3. Further tightening of nut 5 presses hooks 4c into the inner wall of pipe 3 and the seal 2 against - the outer wall of pipe 3, thereby creating a firm, water tight connection.

The position of end cap 6 can be adjusted without affecting the connection between the pipe 3 and connector 1 as this fits between the tightening member 5 and the third section 43 of spigot 4. This allows the fitting between the connector 1 and a branch pipe to be changed and adjusted without any effect on the connection with the main pipe 3.

When it is desired to remove connector 1 from pipe 3, tightening member 5 is loosened and the second section 42 of spigot 4 is pushed against flange lb. This moves lugs 4e out of alignment with lug engagement surfaces le and hence allows arms 4b to be distorted to allow hooks 4c to pass through hole 3a.

The connector 1 can therefore be quickly and easily secured and fastened to pipes without requiring separation of the components of the connector. The flow path through the connector is also kept as open as possible as all threaded connections are situated outside of the flow path. Both the lugs and lug engagement surfaces have a minimal circumferential length and so do not greatly interfere with the flow path.

Although the connector of the present invention has been described in relation to use in a branch pipe connection, the skilled man would readily envisage other means of utilising this connector. For example, the connector could be used to connect two adjoining pipes or could be used to connect one pipe to a plurality of branch pipes.

Claims (1)

1. - 16 - Claims: 1. A pipe connector for connecting a branch pipe to a main

   pipe, the main pipe having a hole in its wall, the connector comprising; a spigot member comprising a hollow cylindrical body and gripping arms extending in the axial direction, the gripping arms being moveable beLween a first position, in which the arms can be inserted and removed from the hole in the main pipe, and a second position, in which the arms cannot be inserted or removed from this hole, the gripping arms comprising an abutment surface for abutment with an inner wall of the main pipe when the gripping arms are in the second position and a lug; a locking member comprising a hollow cylindrical body coaxial with the spigot member and lug engagement surfaces for substantially preventing the movement of the lug towards the first position; and a tightening means for fixing the connector to the main pipe by axial movement of the locking member relative to the spigot member so as to at least partially align the lugs and lug engagement surfaces to prevent the movement of the gripping arms into the first position.

   2. A pipe connector as claimed in claim 1, wherein the axial displacement necessary to bring the liigs into or out of at least partial alignment with the lug engagement surfaces is less than the axial length of the gripping arms.

   - 17 - 3. A pipe connector as claimed in claim 1 or 2, wherein the gripping arms are deflectable between first and second positions.

   4. A pipe connector as claimed in claim 3, wherein the first position is a deflected position and the second position is a non deflected position.

   5. A pipe connector as claimed any preceding claim, wherein the lug is a protrusion.

   6. A pipe connector as claimed in any preceding claim wherein the lug comprises a shoulder at the end closest to the hollow cylindrical body of the spigot member, movement of the gripping arms into the first position being possible when the lug engagement surface is moved beyond the shoulder in the direction of the spigot body.

   7. A pipe connector as claimed in any preceding claim, wherein the spigot member comprises two opposing gripping arms.

   8. A pipe connector as claimed in claim 7, wherein the connector further comprises a marker visible on the exterior of the connector adapted to indicate the orientation of the gripping arms.

   9. A pipe connector as claimed in claim 8, wherein the marker comprises raised lines in the plane of the two gripping arms. - 18-

   10. A pipe connector as claimed in any preceding claim, wherein the gripping arms extend through the locking member.

   12. A pipe connector as claimed in any preceding claim, wherein the abutment surface abuts against the internal circumference of the main pipe.

   13. A pipe connector as claimed in claim 12, wherein the abutment surface comprises a protrusion extending radially outwards from the gripping arm.

   14. A pipe connector as claimed in claim 13, wherein the abutment surface comprises a hook.

   15. A pipe connector as claimed in claim 13, wherein the abutment surface comprises a wedge.

   16. A pipe connector as claimed in any preceding claim wherein the lug engagement surfaces comprise ring shaped protrusions which encircle the gripping arms.

   17. A pipe connector as claimed in any preceding claim wherein the tightening means acts to alter the axial position of the spigot member.

   18. A pipe connector as claimed claim 17 wherein the tightening means comprises a nut in threaded engagement with the spigot member.

   19. A pipe connector as claimed in any preceding claim wherein the tightening means is located on the exterior of the connector.

   - 19 - 20. A pipe connector as claimed in any preceding claim, wherein the locking member is adapted to directly contact, in use, the outer surface of the main pipe.

   21. A pipe connector as claimed in claim 20 wherein the locking member comprises a seal at the end adapted for contact with the main pipe.

   22. A pipe connector as claimed in any preceding claim, wherein the connector further comprises an additional component for attachment to the branch pipe, the additional component being operabley independent from the tightening means.

   IS 23. A pipe connector for connecting a branch pipe to a main pipe, the connector comprising; a spigot member for connection to the main pipe, the spigot member comprising a flow path and gripping means, the gripping means being moveable between a first position and a second position, wherein in the first position the gripping means can be inserted into and removed from the main pipe and in the second position the gripping means cannot be inserted into or removed from the main pipe; a locking means comprising locking portions which are capable of locking the gripping means in the second position when the locking portions are correctly aligned with the gripping means; and an activating means for positioning the locking portions in correct alignment with the gripping means; wherein the activating means is located outside of the flow path.