GB2163081A

GB2163081A - Heating apparatus for solder

Info

Publication number: GB2163081A
Application number: GB08421059A
Authority: GB
Inventors: Andrew John Homer
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-08-18
Filing date: 1984-08-18
Publication date: 1986-02-19
Also published as: GB8421059D0

Abstract

Pipes and pipe connectors are heated to a temperature sufficient to melt solder so as to connect the pipes by heating parts (10, 11) each provided with at least one pair (12, 13, 14) of arcuate surfaces, said heating parts (10, 11) having a respective heating element (15) and being situated at the end of arms (16, 17) provided with manually operable handles (22, 23). The heating surfaces may be provided with a groove-like recess to accommodate a solder filled ridge provided in the pipe connector, or other "adhesive" accommodating formations. <IMAGE>

Description

SPECIFICATION Heating apparatus The present invention relates to heating apparatus primarily but not exclusively, for heating solder so as to enable two articles to be connected together by soldering.

The present invention is also primarily but not exclusively concerned with the connecting of pipes by soldering.

It is known to connect pipes by providing connector means in the form of a tube having an internal diameter slightly greater than the external diameter of the pipes to be connected. The pipes and connector are then heated to a temperature at which solder may flow between the inner surface of the connector piece and the outer surface of the pipes to be connected, thereby causing a bond between the pipes and the connector. On cooling, the pipes are soldered to the connector.

It is also known to provide connector means which comprises an annular storage space for each pipe to be connected, such storage space includes solder in solid form which, when heated, flows over the inner surface of the connector means and the outer surface of the pipe to be connected.

The heating of the connector and the pipe has in the past been affected by a flame, a common appliance being a blowiamp having any suitable fuel such as gas, e.g. butane or propane, or liquid fuel such as paraffin applied to a burner under pressure.

Whereas such a method of connecting pipes is satisfactory, problems can occur with the use of a naked flame particularly where pipes have to be connected in proximity to either highly inflammable materials or surfaces, or materials or surfaces which may pot themselves be readily inflammable but may be damaged by the use of a naked flame in proximity thereto, It is often necessary to provide around an area where pipes have to be connected, guard means to guard such surfaces, which guard means may for example comprise sheets of asbestos, which operation is not only time consuming but often necessitates the use of asbestos material which may itself present an undesirable health hazard.

It is an object of the present invention to provide a new or improved apparatus that overcomes or minimises the abovementioned problems.

According to one aspect of the present invention, I provide heating apparatus comprising a pair of arcuate concave heating surfaces, each having substantially the same radius of curvature, said surfaces being movable towards and away from each other, and heating means for heating said surfaces.

The provision of a pair of relatively movable concave heating surfaces permits of positioning of said surfaces on either side of a pipe or pipe connector thereby enabling the transfer of heat from the heating apparatus to the pipe or pipe connector.

When the heating apparatus is to be used in the connection of pipes interconnected by means of solder, the heating means will enable the surfaces to be heated to a temperature such that the heat imparted to the pipe and pipe connector by said heating apparatus is sufficient to enable the melting of solder.

It is another object of the present invention to provide a new or improved method of connecting pipes.

According to another aspect of the invention, I provide a method of heating pipes and/or connector means to a temperature to enable solder to flow over the surfaces thereof, comprising the steps of positioning electrically energised heating means around a substantial part of a surface of revolution around the circumference of said pipe or pipe connector and heating said pipe and pipe connector to a temperature whereby solder will flow over the surfaces thereof.

Preferably the heating surfaces together extend around at least half of the circumference of said pipe and/or connector means. Preferably, each of said heating surfaces contacts said pipe or pipe connector means at spaced positions substantially diametrically opposite each other.

Preferably said heating means comprises an electrically energisable element. Conveniently, at least one such element is provided in close proximity to each heating surface.

Preferably two or more pairs of arcuate concave heating surfaces are provided, the radius of curvature of each pair being such that a respective pair of surfaces conforms to a standard size pipe. Preferably, three such pairs of surfaces may be provided, one pair of surfaces having a radius of curvature in the region of 8.5mm, the second pair of surfaces having a radius of curvature in the region of 12mm and the third pair of surfaces having a radius of curvature in the region of 15mm.

The abovementioned sizes will permit of use of the apparatus on connectors for copper pipe sizes of 15mm, 22mm and 28mm respectively which are commonly used copper pipe sizes in domestic and commercial premises.

Preferably, said pair or pairs of surfaces are provided adjacent the end of a pair of respective arms, each arm being connected to a manually operable part or handle comprising a material which is both electrically and thermally insulating and conveniently said handles are mounted relative to each other in a manner to permit of limited pivotal movement so as to provide for movement of the surfaces of each pair towards and away from each other.

Preferably, one or both of said handles incorporates switch means to control the supply of electrical energy to the or each electrical heating element.

Preferably, means are provided to bias the surfaces of each pair in a direction towards each other thereby enabling the apparatus to be "self-clamping", in an operative position, on a pipe to which soldering is to be effected.

As an alternative to or possibly in combination with said biasing means, further clamp means may be provided which may include an overcentre locking device whereby said apparatus may be clamped in an in-use position on a pipe.

Preferably, each surface of said pair is provided on a heating part which also incorporates said heating element.

Said heating part may be provided with a further arcuate concave surface with a radius of curvature smaller than the radius of curvature of said previously mentioned pairs of arcuate surfaces, such further surfaces conforming to a size of connector commonly used for "microbore" pipes, the external diameter of which pipe may be 8mm or 10mm.

Preferably one of said heating part is provided with a further arcuate concave surface of a size to conform with connectors for connecting 10mm mi crobore pipes and the other heating part is provided with a further arcuate concave surface of a size adapted to conform to connectors used on 8mm microbore pipes.

Preferably each of said electrically energisable heating elements is of a power of at least 100W and conveniently the power of each heating ele ment in the region of 250W-300W.

Each heating element may comprise two or more separately energisable elements to enable the heating output to be increased where desired, for example for use on pipes of large diameter, e.g. 28mm diameter.

It is further envisaged that said heating elements may have a stand-by low power consumption whereby the heating parts which present said surfaces are maintained above ambient temperature and a second higher consumption in which consid erably more energy is supplied during use of the apparatus to effect a soldering operation.

Alternatively, a single element may be provided which may be controlled in a manner whereby the power supplied thereto is adjustable which conve niently may incorporate a solid state electronic control incorporating solid state switching devices, such as thyristers, triacs or the like.

In a case where said surfaces of a pair are provided at one end of a pair of arms, preferably one of the arms is bent so as to facilitate the use of the apparatus on a pipe which is in close proximity to a wall or other partially obstructing surface.

It is further envisaged that the apparatus and method of the present invention may be used for connecting metallic pipes or non-metallic pipes which are not connected by solder but in which an adhesive such as a thermosetting resin may be used, which requires at least for a short period a temperature considerably higher than ambient temperature to enable relatively rapid curing of the adhesive.

The invention will now be described in more detail by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a side elevation of one embodiment of the apparatus embodying the invention; Figure 2 is an enlarged perspective view of part of the apparatus shown in Figure 1.

Referring to the Figures, the embodiment shown comprises a first heating part 10, a second heating part 11, the heating parts 10 and 11 defining three pairs of arcuate concave heating surfaces, a first pair 12, a second pair 13 and a third pair 14.

The heating part 11 is provided with an electrically energised heating element 15 supplied via a cable, shown in dotted outline at 16 The heating part 10 is provided with a similar electrically energised heating element (not shown) supplied with power from a cable 17, the cables 16 and 17 being connected to a control circuit 18 provided with a manually operable control member 19.

The heating element 10 is mounted at the end of arm 20 and the heating part 17 is mounted on arm 21, the arms 20 and 21 being secured to- respective handles 22 and 23 respectively. The handle 22 is provided with a hinge part 24 and the handle 23 is provided with a hinge part 25, the hinge parts 24 and 25 being interconnected by a pin 26.

Biasing means in the form of a spring 27 bears against surfaces provided on the hinge parts 24 and 25 to cause the heating parts 10 and 11 to be biased in a direction towards each other.

Manual operation of the handles 22 and 23 in a direction to move the handles towards each other, i.e when squeezed by the hand, will move apart the heating parts 10 and 11.

A cable 30 connects the control circuit 18 to a source of electrical supply.

The heating part 10 is provided with a further arcuate surface 31 and the heating part 11 is provided with a further arcuate surface 32, the arcuate surfaces 31 and 32 having a radius of curvature considerably smaller than the radius of curvature of the surface parts 12, 13 and 14.

Referring now in addition to Figure 2, use of the apparatus will be described.

A first pipe 35 is to be connected to a second pipe 36, which pipes may for example be made from copper, the connection being made by a connector piece 37 which has an internal diameter slightly larger than the external diameter of pipe parts 35 and 36. The connector 37 includes- annular formations 38 and 39 each of which are filled with solder on the inside thereof.

In order to effect connection of the two pipe parts 35 and 36, after the pipe has been duly cleaned and flux applied thereto, the heating apparatus of the present invention is positioned around the solder ring 39, as shown in Figure 2, and the electrically energised heating elements such as the element 15 are energised causing the solder 39 to melt and flow between the connecting part 37 and the second pipe part 36, and as soon as the solder flows over the surfaces of the pipe and connector piece 37 the heat may be removed, and on cooling, the connector 37 will be securely soldered to the pipe 36. The handles 22 and 23 are then depressed, the apparatus removed from the solder ring 39 and placed around the solder ring 38 and the operation repeated.

It can be seen in Figure 2 that each of the pairs of concave arcuate surfaces 12, 13 and 14 is provided with a groove, such as the groove 40 shown in the arcuate part 14, and the groove 41 shown in the arcuate part 13, so that the heating part 11 may conform as closely as possible to the surface of the connector 37. Similar grooves are of course provided in the heating part 10.

It will be appreciated that only one type of connector has been described above and other connectors exist in which no "inbuilt" solder is provided, and with such other connectors it is necessary for solder to be introduced at the end of the connector piece, such pipe connectors being known as "end-feed" fittings and, for use with such fittings the heating parts 10 and 11 have a substantial surface area that conforms to the external surface of the connector part so as to ensure that sufficient heat is imparted to and conducted through the connector to the pipes to be connected.

The heating apparatus of the present invention is equally applicable to the connection of pipes through T-connecting pieces and any other similar connectors which may be designed to cope with the connection of pipes of different size.

The further arcuate formations 31 and 32 are of smaller-radius of curvature and designed to conform to connectors used in microbore piping, the piping having an external diameter of 8mm or 10mm and it can be seen that the area of contact between the heating means and the pipes, in this case is smaller than that provided with the pairs of arcuate surfaces. However, because of the smaller diameter of the pipe, and the provision of heating means in the heating parts 10 and 11 capable of dealing with larger diameter pipes, the area of contact is sufficient to ensure satisfactory heating of a solder type connector for microbore piping.

Whereas the embodiment above described has been shown to have three pairs of arcuate surfaces to deal with the connection of pipes of, for example, 15mm, 22mm and 28mm, it is envisaged that the heating parts 10 and 11 may be provided with a single pair of arcuate surfaces for use with a specific diameter pipe. Furthermore, the heating means may be provided with interchangeable heating parts 10 and 11, such interchangeable parts each affording a pair of arcuate surfaces to deal with a specific diameter of pipe and in this case, the heating elements would preferably remain secured to the heating means and the arcuate surfaces attached in a manner to ensure good conductivity to the heating elements, but also being readily detachable so that they may be changed for any other desired size.

The control means 18 and manually operable control member 19 may comprise a switch to enable the heating elements to be either switched on or off, or alternatively may comprise a more sophisticated arrangement adapted to energise or deenergise one or more heating elements provided in each heating part, or alternatively control the supply in a variable manner for use, for example, of a solid state switching circuit.

The arm 20 is provided with a bend in the region 45 so as to enable use of the heating means in close proximity to a wall or other surface, the bend 45 enabling the handle 22 to be-spaced from said wall or other surface.

The handles 22 and 23 are preferably made from a material that is both electrically and thermally insulating.

Whereas the above description relates primarily to the connection of copper pipes using solder, it is envisaged that the heating means of the present invention may be used to heat an adhesive so as to bond together two pipes, which need not necessarily be made from copper but may be made of any suitable material, for example a plastics material, furthermore, where the pipes are made of a plastics material, the heating means of the present invention may be used to heat the pipes to a sufficient temperature so that the material from which the pipes themselves are made begins to change to a liquid state so as to "weld" the two pipes together without the use of additional adhesive.

It will be appreciated that welding of plastic pipes is virtually impossible with a blow lamp or the like since the heat applied by the flame of the blow lamp cannot be localised to a sufficiently small area, whereas the heating means of the present invention enables the heat to be applied to a specific area so as to enable a change in state to pipe material in a localised area without deforming or otherwise damaging the remainder of the pipe.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed results, may, separately or any combination of such features, be utilized for realising the invention in diverse forms thereof.

Claims

1. Heating apparatus comprising a pair of arcuate concave heating surfaces, each having substantially the same radius of curvature, said surfaces being movable towards and away from each other, and heating means for heating said surfaces.

2. Heating apparatus according to Claim 1 wherein said heating means enables said heating surfaces to attain a temperature sufficient to melt lead based solder.

3. Heating means according to Claim 1 or Claim 2 wherein said heating apparatus comprises more than one pair of areuate concave heating surfaces, each surface of said pair having substantially the same radius of curvature, the radius of curvature of said pairs of surfaces being different from each other.

4. Heating apparatus according to any one of the preceding claims wherein said heating means comprises an electrically energisable element.

5. Heating apparatus according to any one of the preceding claims wherein the or each pair of heating surfaces are provided adjacent the end of a pair of respective arms, each said arm being connected to a manually operable part or handle and wherein said arms or handles are mounted relative to each other in a manner to permit of limited pivotal movement therebetween to permit of move ment of said surfaces of each pair towards and away from each other.

6. Heating apparatus according to Claim 5 wherein said handles are made at least partially from a material which is thermally insulating.

7. Heating apparatus according to Claim 5 wherein said thermally insulating material is also electrically insulating.

8. Heating apparatus according to any one of Claims 5 to 7 wherein one or both of said handles incorporates switch means to control the supply of electrical energy to the or each heating element.

9. Heating apparatus according to any one of Claims 5 to 8 wherein means are provided to bias the surfaces of each pair of heating surfaces in a direction towards each other.

10. Heating apparatus according to any one of Claims 5 to 9 wherein clamp means are provided for clamping the surfaces of each pair around an object to be heated.

11. Heating apparatus according to Claim 10 wherein said clamping means comprises an overcentre locking device.

12. Heating apparatus according to any one of the preceding claims wherein each surface of said pair is provided on a heating part, said heating part further comprising an electrical heating element.

13. Heating apparatus according to any one of the preceding claims wherein said heating means comprises electrically energisable heating elements and wherein control means are provided whereby the power supplied to the or each heating element may be varied from a first low level to a second higher level.

14. Heating apparatus according to Claim 13 wherein solid state control means are provided whereby the power supplied to the or each heating element may be adjusted in a variable manner.

15. Heating apparatus according to any one of the preceding claims wherein the surfaces of said pair are provided by a respective heating part and wherein the radius of curvature of each said surfaces is in the region of 8.5mm.

16. Heating apparatus according to Claim 15 wherein each heating part has two surfaces, the radius of curvature of the other surface being in the region of 12mm.

17. Heating apparatus according to Claim 16 wherein each heating part has three surfaces, the radius of curvature of said third surface being in the region of 15mm.

18. Heating apparatus according to any one of Claims 15 to 17 wherein each heating part has a further convex surface, the radius of curvature of the further surface on one heating part being in the region of 4mm and the radius of curvature on the surface on the other heating part being in the region of 5mum.

19. Heating apparatus according to any one of the preceding claims wherein each surface of said pair of surfaces are provided adjacent the end of a respective arm and wherein one of said arms is substantially straight and the other of said arms is bent so that in an at rest position that end of the bent arm having said heating surface is nearer to the straight arm than the remainder of said bent arm.

20. A method of heating pipes and/or connector means to a temperature to enable solder to flow over the surfaces thereof, said method comprising the steps of positioning electrically energised heating means around a substantial part of a surface of revolution around the circumference of said pipe or pipe connector and heating said pipe and pipe connector to a temperature whereby solder will flow over the surfaces thereof.

21. A method of heating pipes and/or connector means according to Claim 20 incorporating the use of heating apparatus as claimed in any one of Claims 1 to 19.

22. Heating apparatus substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2 of the accompanying drawings.

23. A method of heating pipes and/or connector means substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

24. A method of connecting pipes substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

25. The apparatus incorporating any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.

26. A method of heating pipes including any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.