GB2165906A

GB2165906A - Improvements in extensible connectors

Info

Publication number: GB2165906A
Application number: GB08521531A
Authority: GB
Inventors: Luigi Cazzaniga
Original assignee: Cazzaniga SpA
Current assignee: Watts Industries Italia SRL
Priority date: 1984-09-06
Filing date: 1985-08-29
Publication date: 1986-04-23
Also published as: DE8525261U1; FR2569818B3; NL8502454A; GB8521531D0; SE8504117D0; FR2569818A3; SE8504117L; ES288897Y; BE903184A; ES288897U; IT8423024V0

Abstract

An extensible connector for plumbing systems comprising a hollow metal tube 4 featuring on its end a part-spherical surface 6 and a ring nut 7 and on the other end a threaded union 9,19,20 featuring a flat compression washer 12, the said metal tube 4 being slideable between a minimum (Fig. 3 not shown) and maximum extension, Fig. 1. <IMAGE>

Description

SPECIFICATION Improvements in extensible connectors This invention relates to connectors and concerns extendible connectors for fluid systems such as plumbing systems.

Domestic central heating systems incorporate radiators attached to the structure of the building which are supplied via pipes and regulation and shut-off valves.

For making the connection between the valves and the feed and return attachments of the radiators threaded union components are used which are sealed by applying tapes, caulk, paste or the like onto the relevant threads to ensure tightness.

This operation is usually carried out with the radiator and pipes fixed in their position and the union components must be screwed to the appropriate extent to compensate for the inevitable errors or differences in the positioning between the radiators and the pipes.

When making the compensating adjustment several attempts have to be made, progressively increasing how far the thread is screwed until it reaches a value corresponding to the distance required. This type of adjustment cannot however be undertaken in the opposite direction, with partial unscrewing of the parts constituting the connection element, except for very small amounts, since this process can damage the fitting and endanger the seal on the thread. Wherever this is required, the connection element has to be disassembled, a new fitting has to be applied to the threaded coupling and then the parts have to be tightened up again to a lesser degree, proceeding by trial and error up to the final correct value.

The assembly procedure described above therefore proves long and laborious and has a marked affect on the assembly costs for the whole central heating system.

The problem is therefore to provide a group of connections which makes it possible to offer rapid dimensional adaptation to the different installation positions of the pipes and radiators, with easy assembly and a secure and long-lasting means of sealing.

Known connection elements consist of several individual elements which have to be assembled to each other before or during the assembly of the heating system.

The said elements also usually incorporate a metal tube with an hemi-spherical end designed to be tightened by means of a ring nut against a conical seat present in the outlet of the valve coupling, thereby creating the seal.

This seal is efficient enough but may be jeopardized by possible defects or damage caused to the hemi-spherical surface or the conical seat, so that the correct surfaces of revolution are no longer provided.

Couplings with elastomeric inserts that can be tightened have been designed, but these products, of great thickness and subject to relevant deformations, have proven to be short-lived.

An object is therefore to produce a connection device with its constituent parts already assembled and which is able to compensate for superficial damage to some of its constituent parts. The connection device may provide a coupling between metallic surfaces of revolution.

According to the invention there is provided an extensible connector suitable for plumbing systems and the like, comprising a hollow metal tube having at one end a part-spherical surface and a ring nut for tightening the partspherical surface against a complementary, such as conical, seat of a threaded outlet of a first component, such as a valve or the like, and having at its opposite end a threaded union arranged to be screwed into a threaded hole of a second component, such as a radiator connection or the like, a flat washer arranged to be sealingly tightened against the second component by the union, the said metal tube being slideable through the said threaded union along a length defining a maximum and a minimum extension of the connector, and compression parts arranged to provide a seal between the said metal tube and the said union in all positions of the metal tube.

These and other results are obtained, according to the present invention by a group of extensible connectors for plumbing systems and the like which consists of a hollow metal tube featuring on its end an hemi-spherical surface and a ring nut designed to tighten this against a conical seat of a threaded valve outlet or the like, and featuring at the opposite end a threaded union designed to be screwed between a threaded hole of a radiator connection or the like, the said tube being able to slide between the said threaded union along a section contained between a maximum extension and a minimum extension, with compression parts present that can be tightened, designed to provide the seal between the said metal tube and the said union in all positions of the said horizontal slide of the metal tube itself.In greater detail, the said threaded union features a first hollow section in a polygon shape and a second hollow cylindrical section, containing on its inside a threaded sleeve screwed onto the end thread of the said metal tube including a widened length with a polygon surface designed to couple itself in a way that is axially slideable and rotationally locked with the said first hollow section and a second cylindrical length working on the end against a ring washer surrounding a conical flaring of the said metal tube, the said ring washer being able to be driven by the said sleeve on the said flaring, exerting compression force on the flaring itself and on the in side cylindrical wall of the said union, following a reciprocal screwing rotation of the said metal tube and of the said union, the relative rotation being impeded between the said sleeve and the said threaded union.The said ring washer can be a metal washer, suitably made of copper, or it may even be made of elastomer material if suitable.

In addition to the said ring washer the said metal tube features a seat designed to accommodate a toroidal washer in elastomer material, exerting compression force against the inside cylindrical wall of the said union.

In order to make assembly easier, the said metal tube features one or more external flattened areas designed to allow gripping with a wrench or the like.

The part-spherical surface of the end of the said metal tube has a covering in elastomer material of limited thickness; a suitable thickness for the said covering made of elastomer material for the said part-spherical end surface is less than 0.4 mm.

For maximum ease of use the elements that make up The connection group according to the invention are assembled with each other before use, there being present on the said metal tube an element for axial stop designed to prevent accidental disassembly of the elements themselves.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a view, partially cut-away, of a connector according to the invention in the maximum extension position, with the washers not tightened.

Figure 2 shows the connector of Fig. 1, with the washers tightened against the radiators.

Figure 3 shows the connector in the minimum contraction position, with the washers tightened.

As shown in Fig. 1, a radiator 1 is coupled to a valve via a connector 3. The said connector incorporates a hollow metal tube 4, having on one end a threaded union 5 for coupling to the radiator, and, on the other end, a section with a part-spherical surface 6, fitted with a ring nut 7 for coupling it to the threaded outlet 8 of a valve 2.

The threaded union 5 has an external thread 9 for insertion in the threaded hole 10 of the radiator, usually with a wide diameter, adjoined by a flange 11 formed with a seat for a washer 12 made of elastomer material arranged to provide a seal when the union 5 is tightened against the surface 13 of the radiator 1. The thickness of the washer 12 and the depth of its seat in the flange 11 is dimensioned in such a way that, on tightening, the surface of the end 14 of the flange 11 lies flush against the surface 13 of the radiator 1, having compressed the washer 12 of the required size to provide a proper seal.

This therefore provides the advantage of optimum compression of the washer 12, and furthermore, the washer 12 is protected from external light, so that it should have a longer life.

Inside the union 5 there is a first portion with an embedded polygon, such as hexagonal, shape 15, and a subsequent hollow cylindrical portion 16.

Between the first polygonal section 15 of the union 5 a sleeve 17 is inserted which has one end 18 widening to a polygonal, such as hexagonal, shape to provide a coupling axially slideable and rotationally blocked with the said section 15, and having an interned thread 19 designed to engage with a thread 20 provided on the end of the metal tube 4.

Formed in the thread 20, a short distance from its start, is a flattened length portion 21, arranged to accept an elastic locking ring 22, designed to prevent accidental disassembly of the connector before it is put into use.

At the other end of the thread 20 the metal tube 4 has a frusto-conical flared part 23, whose aperture angle is conveniently less than 800.

Around this there is a twistable compression ring 24, conveniently made of metal, such as copper, or other suitable washer material, with good reliability. Extending from the conical widening 23, the said metal tube has a cylindrical length 25, on which is formed a seat for a toroidal washer 26, designed to exert compression force on the cylindrical surface 16 of the union 5.

The metal tube 4 then extends to a cylindrical section 27 whose diameter is greater than that of the length 25, on which are shaped two or more opposing flat portions 28, designed to allow gripping with a wrench for tightening.

The metal tube 4 ends with the part-spherical surface 6, onto which can be conveniently applied a surface covering 29 made of elastomer material, having a thickness not greater than 0.4 mm, designed to compensate any imperfections or superficial damage to the complementary, somewhat frusto-conical, seat 30 on the outlet 8 of the valve 2, without the seal being jeopardized however by a washer made out of elastomer material that is too thick.

Between the cylindrical section 27 and the part-spherical surface 6 is located a circular relief 31 designed to provide support for the ring nut 7 when it is tightened on the outlet 8.

Using the completely assembled connector according to the invention, the coupling between the radiator 1 and the valve 2 can be effected quickly, easily compensating any differences in the distance between the radiator 1 and the valve 2, already connected beforehand to the pipes of the system.

The operation starts with the connector at its minimum length, in which the threaded union 5 pushes against the start of the cylindrical section 27, on the complete tightening of the union 5 onto the radiator, with a seal formed by the washer 12.

The connector can then be extended by sliding the metal tube 4 through the threaded union 5, until the spherical surface 6 is brought into contact with the frusto-conical surface 30 of the outlet 8 of the valve 2.

Rotating the metal tube 4 with a wrench applied to the flattened portions 28, results in a tightening of the metal tube 4 itself between the sleeve 17, which sleeve is prevented from turning as its polygonal shaped end 18 is engaged in the corresponding polygonal hole 15 and acts on the compression ring 24 pushing it onto the frusto-conical surface 23 until it is tightened against the surface 16, as shown in Fig. 2, thereby improving the effectiveness of the compression effected by the ring washer 26.

The use of a ring 24, in copper in particular, provides a seal that is secure for a long time, and which can also be improved, in the event of deterioration even after a long period, with a further tightening of the metal tube 4.

Once the metal tube 4 is tightened the assembly can then be completed by definitively tightening the ring nut 7 on the outlet 8 of the valve 2.

The complete operation of the connector is between the maximum contraction, shown in Fig. 3, and the maximum extension, shown in Fig. 1 and Fig. 2, with the widening 18 close to the far surfaces of the polygonal shape 15, beyond which it is not possible to extend the union. Such an operation can be achieved by dimensioning the lengths of the various component parts, the threaded union 5 and the metal tube 4, in such a way as easily to compensate tolerances of positioning between valve and radiator.

The metal washers 24 also have the function, when tightened, of constituting a mechanical lock for the extension of the union, thereby preventing deformation after assembly, for example due to internal pressure or mechanical causes.

As this technique shows, although it has been described with particular reference to the coupling between valve and radiator in central heating systems, connectors according to the invention can be implemented in many different applications, wherever its design features prove advantageous.

Claims

1. An extensible connector suitable for plumbing systems and the like, comprising a hollow metal tube having at one end a partspherical surface and a ring nut for tightening the part-spherical surface against a complementary seat such as a substantially frustoconical seat, of a threaded outlet of a first component, such as a valve or the like, and having at its opposite end a threaded union arranged to be screwed into a threaded hole of a second component, such as a radiator connection or the like, a flat washer arranged to be sealingly tightened against the second component by the union, the said metal tube being slideable through the said threaded union along a length defining a maximum and a minimum extension of the connector, and compression parts arranged to provide a seal between the said metal tube and the said union in all positions of the metal tube.

2. A connector according to claim 1, in which the said threaded union comprises a first hollow portion of polygon shape and a second hollow cylindrical portion containing on its inside a threaded sleeve screwed on an end thread of the said metal tube, the sleeve including a portion of increased dimension with a polygon surface arranged to couple in an axially slideable and rotationally locked manner with the said first hollow section, and an end of the second cylindrical portion surrounding a ring washer itself surrounding a frusto-conical flared part of the said metal tube, the said ring washer being capable of being driven by the said sleeve on the said flared part, exerting compression force on the flared part itself and on the inside cylindrical wall of the said union, following a screwing rotation of the said metal tube relative to the said union, relative rotation between the said sleeve and the said threaded union being impeded by the engagement of the polygon shaped portion of the sleeve in the polygon shaped hollow portion of the union.

3. A connector according to claim 2, in which the said ring washer is a metal washer, suitably made of copper.

4. A connector according to claim 1, 2 or 3, in which the said flat ring washer is made of elastomer material.

5. A connector according to any one of the preceding claims, in which the said metal tube has a seat for accommodating a toroidal washer of elastomer material arranged to exert a compression force against the inside cylindrical wall of the said union.

6. A connector according to any one of the preceding claims, in which the said metal tube has one or more external flat portions designed to allow gripping with a wrench or the like.

7. A connector according to any one of the preceding claims, in which the part-spherical surface of the end of the said metal tube has a covering of elastomer material of limited thickness.

8. A connector according to claim 7, in which the said covering of elastomer material for the said part-spherical end surface is equal to or less than 0.4 mm in thickness.

9. A connector according to any one of the preceding claims, in which its constituent parts are assembled prior to use, there being present on the said metal tube an axial stop member for preventing accidental disassembly of the constituent parts themselves.

10. A connector substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.