GB2028450A

GB2028450A - Improvements in or Relating to the Connection of a Spigot into a Socket

Info

Publication number: GB2028450A
Application number: GB7929539A
Authority: GB
Original assignee: Palmer J A; Palmer M R
Current assignee: Palmer J A; Palmer M R
Priority date: 1978-05-25
Filing date: 1979-08-24
Publication date: 1980-03-05

Abstract

A method of securing a spigot into the threaded boss of a radiator or other structure avoids the necessity for screw threaded or other fitting requiring a sealing compound. The radiator 1 provided with a threaded boss 2 is engaged by a spigot 4 which has bonded to the outer surface and at one end a rubber material 7 including a laterally extending flange 8. This fitting may include customary gland connection 6 for securing to a radiator valve. The interior of the spigot 4 is engaged by an expanding tool which produces an outward compressive force serving to firmly engage the rubber sealing material 7 with the threads of the boss 3 and to produce a permanent leak-free connection. There is also disclosed an expanding tool (Figure 7) suitable for effecting the joint, and comprising a draw rod 10 with a tapered end 11, which provides radially outward movement of a plurality of segments 12 loosely held in a body structure 13. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to the Connection of a Spigot into a Socket This invention relates generally to the connection of a spigot member into a socket and is more particularly concerned with the provision of a simple method for connecting a valve or the like spigot into the threaded socket or boss provided on a central heating radiator. Hitherto, such connections have been made by screw thread engagement using PTFE tape or other jointing medium to prevent leakage. Such a method of fitting is time consuming and not always reliable.

According to this invention there is provided a method of securing a spigot into a boss in which method an end of the spigot is provided with a resilient sealing means over its surface, and thereafter introduced into the boss, the spigot being outwardly expanded by deformation of the material thereof to produce forceful compression of the sealing material against the inner surface of the boss to bond same therein.

In one specific embodiment provided for securing a spigot to a central heating radiator a short length of copper tube includes a thin film or sleeve of rubber or like elastomeric material bonded to the outer surface at one end, and the tube and material are passed through the threaded boss or socket of the radiator, thereafter expansion of the copper tube is effected by an appropriate tool causing the material to be forced into the threading of the socket and thereby secured to provide a water-tight joint. The other end of the copper tube will be provided with any convenient form of coupling and in general may include a coupling for connection with a radiator valve.

It is advantageous to apply a bonding liquid or adhesive to the outside of the rubber sleeve and in this respect a Cyanoacrylate Adhesive is preferred. The spigot itself may comprise the aforementioned copper tube adapted to be connected to a radiator valve, or alternatively may be in the form of a hollow plug in order to seal the socket aperture in a radiator. Such a plug may also include an air bleed vent and in such cases the tube will generally lie wholly within the socket and radiator structure with no protruding parts. A particular advantage of the method according to the invention is that substantial tolerances between component parts can be taken up, and that any sub standard threads which are often found in radiator connections do not affect the efficiency of the connection.

In order that the invention may be more fully understood and appreciated reference is now made to the accompanying drawings showing various embodiments by way of examples. In the drawings: Fig. 1 shows a section through part of a radiator connection socket with a spigot connection located therein and ready for expansion, Fig. 2 shows the spigot after expansion and secured into the socket, Fig. 3 shows a further form of spigot comprising a bleed valve located within the socket and prior to expansion, Fig. 4 shows the spigot of Fig. 3 after expansion, Fig. 5 shows a blank spigot inserted into a radiator socket prior to expansion, Fig. 6 shows the blank spigot after expansion, and Fig. 7 shows one form of expanding tool in longitudinal section.

Referring to the drawings, Figure 1 shows part of a radiator structure 1 which includes a socket 2. It is usual for the threading on the socket 3 to taper. A tail connector for a radiator valve comprises a short length of copper tubing 4 which forms a spigot and which includes an annulus 5 at its one end with a securing nut 6 adapted for connection to a radiator valve. The other end of the tube 4includes a rubber sleeve 7 bonded thereto by a suitable agent and including a flange portion 8 as shown.

The annulus 5 may be replaced by shaping the end of the spigot over or around a ring of appropriate cross-section of brass or like material.

In order to effect the joint a bonding liquid is first applied to the outside of the rubber sleeve 7 and the sleeve and pipe introduced into the socket until the flange 8 is in abutment with the end face-thereof. An expanding tool such as that shown in Figure 7 is introduced into the spigot and on operation this produces expansion of the copper tube with the resulting forceful compression of the rubber material and bonding into the threading 3. The expanding tool is then removed to leave the completed joint as shown in Figure 2. This method produces a good mechanical joint which is leakproof and enables reasonable tolerances between the parts to be taken up, and furthermore sub standard threads in the socket are not of importance.

Figures 3 and 4 show a spigot which has an air bleed plug 8 and this generally is fitted by a method as previously described. In this case the whole of the spigot is located within the radiator structure, the method of fitting being the same.

Figures 5 and 6 show a further arrangement in which the spigot comprises a blanking plug which may have a bleed screw valve 9 (Fig. 6) and again this is fitted by a method as previously described.

Figure 7 shows an example of a suitable expanding tool which comprises a draw rod 10 having a conically tapered end 1 1 of which the outer surface cooperates with inner surfaces of a plurality of segments 12 which are loosely secured to a body structure 13 by means of laterally extending flange portions 14 retained by rivets engaging elongate apertures 1 4a. The tool is shown in its unexpanded state and in this condition it may be inserted into the spigot. To produce the expansive force the draw rod 10 is pulled in the direction of the arrow A and the end 11 causes outward expansion of the segments 12, thereby effecting expansion of the pipe. The pulling force on the rod 10 will preferably be provided by a lever cooperating with a stop member so as to prevent over expansion. Using this arrangement reliable and consistent expansion forces can be applied to the spigot thus providing consistency in the joints.

It will be appreciated that the method of the invention can be applied to many fields other than the fitting of valve tails into radiators, and furthermore the other end of the spigot may include a variety of fittings according to the particular purpose in view. The rubber sleeve 7 may be of a natural or synthetic rubber or a plastics material may be used which is bonded onto the end of the spigot tube which is preferably copper. The bonding liquid used advantageously is a Cyanoacrylate Adhesive Type 1.S.415 manufactured by Loctite (U.K.) Limited.

The final bonding material can be protected by film or strips removable prior to the insertion of the tubing in the socket.

Claims

1. A method of securing a spigot into a boss in which method an end of the spigot is provided with a resilient sealing means over its surface, and thereafter introduced into the boss, the spigot being outwardly expanded by deformation of the material thereof to produce forceful compression of the sealing material against the inner surface of the boss to bond said therein.

2. A method in accordance with claim 1, wherein the resilient sealing means comprises a film or sleeve of rubber or like elastomeric material bonded to the outer surface at one end of the spigot.

3. A method in accordance with claim 2, wherein the material comprises a sleeve with a laterally extending flange portion which abuts the face surface of the boss.

4. A method in accordance with any preceding claim, wherein the free end of the spigot is formed with a peripheral protrusion which serves as an olive or abutment surface for a threaded coupling.

5. A method in accordance with any preceding claim, wherein bonding liquid is applied to the outside of the resilient sealing means prior to insertion into the boss.

6. A method in accordance with any preceding claim, wherein the spigot comprises a hollow plug.

7. A method in accordance with claim 6, wherein the hollow plug includes a valve means serving as an air bleed vent.

8. A method in accordance with any preceding claim, wherein the spigot is engaged by an expanding tool comprising a plurality of segments locatable within the spigot and disposed around a conical core member which may be moved longitudinally so as to cause outward compressive force to be applied to the spigot.

9. A method for securing a spigot into a boss of a radiator or like carried out substantially as herein described with reference to the accompanying drawings.

10. A spigot connection with a socket substantially as herein described with reference to and as shown in the accompanying drawings.