GB2124124A - Improvements in or relating to soldering apparatus - Google Patents

Abstract

A soldering apparatus, especially intended for use with a "Yorkshire" type connection used to join two pipes end-to-end, comprises an upper assembly pivoted to a lower assembly at 22. The upper assembly comprises an aluminium jaw member 2 heated by electrical resistance elements (not shown), a heater control 15 for the heating elements, and a handle 4, all joined rigidly together. The lower assembly comprises a jaw member 6 having a downwardly inclined lever element 21 pivotally connected to a locking member 7 having a handle 8 joined rigidly thereto. The lower handle 8 is moved down to open the jaws 2, 6 so that they may be clamped around the Yorkshire connection. Upward movement of the handle 8 causes the locking element 7, the lever element 21 and a lower surface 26 of the upper assembly to interact with an "over centre action" in such a way that the jaws 2, 6 are clamped rigidly together. Heat conducted from the heaters via the jaws 2, 6 to the Yorkshire connection causes solder therein to melt to provide a water-tight seal between a collar of the connection and the pipe. An induction heater may be used instead of an electrical resistance heater. <IMAGE>

Description

SPECIFICATION Improvements in or relating to soldering apparatus This invention relates to soldering apparatus.

When two pipes are to be joined end-to-end, for example during the construction of a domestic central heating system, a connection of the "Yorkshire" type is frequently used. Such a connection comprises a collar having an inside diameter fractionally larger than the outside diameter of the two pipes to be joined (usually 13mm. or 22mm. for such a heating system) and having at least two spacedapart annular beads, formed as inwardly-opening grooves in the collar, each bead being filled with a suitable solder metal. To form the joint, the two pipes to be joined are brought into end-to-end abutment with one another inside the connecting collar and a blow torch is used to melt the solder contained within the beads of the collar so that a water-tight joint is formed between the collar and each pipe.

Whilst such a means of connection is cheaper and simpler than the main alternative, namely the use of a compression connection, it is difficult to apply heat evenly around the periphery of the collar. An uneven application of heat by use of the blow torch can cause deformation of the collar and/or of the pipes and can also cause the solder to flow away from part of the bead so that a gap is left; in either case, the resulting joint may not be properly water-tight.

Additionally there is a significant fire risk whenever a blow torch is used since it has an exposed flame.

The present invention is intended to overcome, or at least mitigate, the disadvantages mentioned above.

Accordingly, one aspect of the present invention provides an apparatus for soldering a first member, provided with a soldering alloy, to a second member, the apparatus comprising two jaws, movable relative to each other and movable to a position in which they surround, or at least partly surround, the first member, and a heating means formed integrally with or directly associated with at least one of the said jaws to heat the first member.

Preferably, the jaws are respectively adapted to surround first members of differing sizes.

Advantageously, the heating means is electrically operated.

Advantageously, the second member is a pipe and the or each first member is a collar connection of the "Yorkshire" type comprising beads filled with sol der. Conveniently, the jaws each comprise at least one groove to accommodate such a bead.

Suitably, there are two opposed said jaws hinged to each other, the arrangement being such that the jaws may be opened to accommodate the first member and then closed.

Preferably, the apparatus comprises two handles, so arranged and so linked to the jaws as to provide an automatic clamping action as the jaws are closed.

Conveniently, to provide such an automatic clamp ing action, a first said jaw has a lever portion angled away from an abutment region of the second said iiw thorn hninn ::1 Inokinn momhor hinnnd tn thn nnid lever portion at a point remote from the said first jaw and adapted to engage the said abutment region to provide an over dead centre action.

Preferably, the heating means comprises at least one electrical resistance heating element which may be embedded in the material of one or other of the said jaws, or may be located within a hole or holes formed within one or both of the said jaws. Advantageously, the jaws are each made of a metal, such as aluminium, to conduct heat from the heating means. Suitably, a thermostatic control means is provided to regulate the temperature of the jaws or a timing means is provided to time the duration of heat production, and the apparatus is preferably provided with heat-insulated handles to assist manual operation. Conveniently, air gaps are provided between the handles and the remainder of the apparatus to hinder conduction of heat from the heating means to the handles.

Instead of comprising one or more electrical resistance elements, the heating means may comprise one or more electrical induction elements, so arranged in the jaws that, in operation of the device, the Yorkshire connection is heated evenly around substantially all of its periphery.

A second aspect of the invention provides a method of joining two pipes to one another in end-to-end abutment by use of a "Yorkshire" type collar connection, the method comprising the steps of sliding approximately half of the collar over the end of one said pipe, apssing the end of the other said pipe into the collar to approach end-to-end the first pipe and, simultaneously or successively, encompassing at least partly the periphery of the collar surrounding one said pipe with jaws and heating the encompassed part of the collar, with heating means formed integrally with or directly associated with or constituted by one of the said jaws, to melt solder contained within that part of the collar, thereby to seal the collar to the said pipe, and also effecting the said encompassing and heating steps with respect to the part of the collar surrounding the second said pipe.

The invention also encompasses two pipes whenever joined in end-to-end substantial abutment by a "Yorkshire" type connection by use of an apparatus or method in accordance with the invention.

So that the invention may be more readily understood and so that further features may be appreciated, a soldering apparatus in accordance with the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is an underneath plan view of the soldering apparatus; and Figure 2 is a part sectional view, slightly shortened, of the apparatus of Figure 1, taken along A-A.

The soldering apparatus illustrated in the drawings comprises, broadly speaking, an upper assembly 1 (as seen in Figure 2) and a lower assembly 5 hinged to one another to provide an arrangement generally resembling a pair of pliers. The apparatus defines a generally longitudinal axis. The upper assemblv 1 comorises. from left to riaht in Fiqure 2, an upper jaw member 2, a heater control compartment 3 and an elongate handle 4, all joined to one another to form a rigid assembly. The lower assembly 5 comprises, again from left to right in Figure 2, a lower jaw member 6, a locking member 7 and an elongate handle 8, the jaw member 6 and the locking member 7 being hingedly connected to one another at 9 and the handle 8 being rigidly connected to the locking member 7.

The soldering apparatus will now be described in more detail. The upper jaw member 2 is made of aluminium and comprises a main generally cuboid portion 10, the upper surface of which tapers downwardlyfrom right to left in Figure 2, and a planar extension 11 extending horizontally to the right from the bottom of the main portion 10. The main portion 10 is provided with two mutually parallel quarter inch diameter (0.64 cm) reamed holes 12 extending generally longitudinally but parallel to the said taper, the two holes 12 being adapted to accommodate respective cartridge electrical resistance heater elements (not shown). In the main portion 10 of the upper jaw member 2, below the two reamed holes 12, two transverse arcuate grooves 13,14 are formed, these two grooves 13,14 opening downwardly from the jaw member 2.The arc of the left-hand groove 13 corresponds to a circle having a diameter of approximately 13 mm, and the arc of the right-hand groove 14 corresponds to a circle having a diameter of approximately 22 mm. In each case, however, an annular medial undercut 13a or 14a, respectively, co-axial with the respective groove, is provided in the groove 13 or 14 and these two undercuts 13a 14a, the purpose of which will be described in due course, thus serve to define regions of each groove 13,14 having a diameter greater than 13 or 22 mm, as appropriate.

The planar extension 11 of the upper jaw member 2 supports a thermostatic heater control 15 which is shielded from accidental contact with the operator of the soldering apparatus by top and side steel cover plates 16. The head of an adjustment screw 17 protrudes through the top cover plate 16 and allows adjustment, for example by means of a screw driver, of the thermostat 15a of the heater control 15, without necessitating removal of the cover plates 16.

The heater control 15 is generally of the sort used in domestic irons, being supplied with electricity by an electrical lead (not shown) and supplying current, in accordance with the control function of a bimetallic strip of the thermostat 15a, to the previouslymentioned cartridge heating elements (not shown) located within the reamed holes 12 in the main portion 10 of the upper jaw member 2.

The handle 4 of the upper assembly 1 is formed of a conventional phenolic resin plastics material and is rigidly joined to the extension 11 of the upper jaw member 2 and to the steel cover plates 16 shielding the heater control 15 in such a way that an air gap 18 is provided between the handle 4 and both the extension 11 and the cover plates 16. This air gap 18 serves to hinder the conduction of heat from the cartridge heaters to the handle 4, to make manual operation of the soldering apparatus more comfortable. The handle 4 is provided with a generally longitudinal tubular hole 19, which may be formed when the handle is moulded or may be drilled in the handle afterwards, to accommodate the electrical lead (not shown) which supplies current from the mains to the heater control 15.

The lower assembly 5 of the soldering apparatus will now be described in detail. The lower jaw member 6 is, like the upper jaw member 2, made from aluminium and comprises a first portion which, in the position illustrated in Figure 2, lies generally parallel to the main portion 10 of the upper jaw member 2, and a lever portion 21, integrally formed with the first portion 20, which, in the position shown in Figure 2, angles downwardly away from the upper assembly 1. A hinged connection 22 having a transverse axis is provided between the upper and lower jaw members 2, 6 adjacent where the lever portion 21 and the first portion 20 of the lower jaw member 6 meet one another. The two jaw members 2, 6 can thus open and close with respect to one another about the hinge 22.

The lower jaw member 6 is provided with two transverse arcuate grooves 23,24which are respective mirror images of the two arcuate grooves 13, 14 provided in the upper jaw member 2, the notional "mirror" being constituted by the plane defined by the points where the upper and lower jaw members 2, 6 contact one another. Thus, the respective annular medial undercut 13a, 14a provided in each of the transverse grooves 13, 14 of the upper jaw member 6 are continued in the grooves 23,24 of the lower jaw member 2.

As stated above, the locking member 7 is hingedly connected at 9 to the end of the lever element 21 remote from the two jaw member 2, 6. This locking member 7 is generally L-shaped, the point of connection with the lever element 21 being at the free end of the short arm of the "L", but differs from a strict "L" shape in that the longer arm of the "L" is prolonged a little beyond the short arm, as at 25.

With the apparatus in the configuration shown in Figure 2, the long arm of the "L" lies generally horizontally, with the upper surface abutting the lower surface of the extension 11 of the upper jaw member 2, and the short arm of the "L" points downwards. The bottom surface of the said extension 11 thus constitutes an abutment surface 26 for the locking member 7. It is to be noted that the transverse edge 27 between the upper surface and the free end of the said prolongation 25 of the locking member 7 is rounded; the importance of this will become apparent in due course.

The handle 8 of the lower assembly 5 is made of a standard phenolic resin plastics material and is attached rigidly to the end of the locking member 7 remote from the two jaws 2, 6 by a self tapping screw. A spacing sleeve 28 is provided between the handle 8 and the locking member 7 to hinder conduction of heat from one to the other.

The soldering apparatus is used to make a Yorkshire connection between two pipes in the following way. A conventional cylindrical collar connection (not shown), provided with two spaced-apart annular beads, each bead opening inwardly and being filled with solder, is placed over the ends of two pipes which are to be joined in end-to-end abutment.

The soldering apparatus is switched on so that electric current is supplied to the heater control 15 and thence to the two cartridge heaters provided within the reamed holes 12 in the upper jaw member 2, the soldering apparatus being in the configuration illustrated in Figure 2 so that heat will readily be conducted from the upper jaw member 2 to the lower jaw member 6. The apparatus is allowed to equilibrate so that the two jaw members 2,6 reach the desired temperature, this having been preset by use of the adjustment screw 17.

The lower handle 8 is then moved downwardly with respect to the upper handle 4 so that the locking member 7 pivots with respect to the lower jaw member 6 away from the extension 11 of the upper jaw member 2, thus freeing the lower jaw member 6 to rotate about the hinge 22 so that the jaw members can be opened. The jaw members are then placed around a part of the collar connection surrounding one of the two pipes to be joined, with the collar being accommodated either within the cylinder defined by the left-hand transverse grooves 13,23 or within the cylinder defined by the right-hand transverse grooves 14, 24, the choice depending upon the dimensions of the collar in question. Care is taken to ensure that the solder-containing bead of the collar is located within the annular undercut 13a or 14a.

The lower handle 8 is then moved upwards so that the free end 25 of the prolongation of the long arm of the "L" of the locking member 7 is brought into abutment with the abutment surface 26 of the upper assembly 1. Continued movement of the lower handle 8 upwards will cause the locking member 7 to pivot with respect to the lower jaw member 6, and the point of contact between the locking member 7 and the abutment surface 26 will shift around the periphery of the free end 25 of the locking member 7 until, with the lower handle 8 lying at an angle of slightly less than 450 to the general axis of the upper assembly 1, the two jaw members 2,6 are brought into firm abutment with one another.Continued upward movement of the handle 8 to the 450 position (at which point the pivot point 9 between the locking member 7 and lower jaw member 6 will be as far as possible from the abutment surface 26) will cause the lever element 21 of the lower jaw member 6 to be bent slightly downwardly with respect to the main portion 20 of the lower jaw member 6, and will also cause the upper surface of the locking member 7 to come into face-to-face engagement with the abutment surface 26 of the upper assembly 1. It will thus be appreciated that such movement of the handle 8 causes the lower assembly 5 to pass a "dead centre" position with respect to the upper assembly 1, so that the two jaw members 2,6 are locked firmly against one another.

This firm locking together of the two jaw members 2,6 allows (a) the "Yorkshire" connection to be gripped securely by the soldering means, (b) heat to be conducted efficiently from the jaw members 2, 6 to the collar of the Yorkshire connection and thus to the solder, and (c) heat to be conducted efficiently from the upper jaw member, which of course is in direct contact with the actual heater elements, to the lower jaw member 6 so that heat is applied substantially uniformly around almost the entire periphery of the "Yorkshire" connection.

The solder contained within the bead of the collar will then melt and the soldering apparatus is removed from the Yorkshire connection by reversing the steps outlined above, in other words by moving the lower handle 8 downwards with respect to the upper handle 4. The solder in the connection will then solidify and the connection of that part of the collar to one of the pipes is complete. The entire procedure is repeated with respect to the part of the collar which surrounds the other of the two pipes to be joined.

It will thus be appreciated that the apparatus described above provides a simple and improved way of creating a "Yorkshire" type connection between two pipes.

A number of modifications of the apparatus described above are possible, and some of these will now be described.

It will have been noted that, when the two jaw members 2, 6 are brought into abutment with one another, there is a gap between (a) the region of the upper jaw member 2 which separates the two transverse grooves 13, 14 of that jaw member and (6) the region of the lower jaw member 6 which separates the two transverse grooves 23,24 of that jaw member. The reason for this is to allow the apparatus to be used to encompass a collar surrounding a standard 22 mm diameter pipe; if this gap were not provided, the two jaw members 2,6 would not open sufficiently widely to accommodate such a collar.However, it is possible to increase the angle at which the lever element 21 of the lower jaw member 6 diverges from the upper assembly 1 (and concomitantly to increase the length of the short arm of the locking member 7) so that the two jaw members 2,6 can be opened more widely. If this is done, then it is possible for the said gap between the two jaw members 2, 6 to be dispensed with, which provides for more efficient heat conduction from the upper jaw member 2 to the lower jaw member 6 and also for more efficient heat conduction from the two jaw members 2,6 to the collar of the "Yorkshire" connection because substantially the entire periphery of the collar is in contact with the jaw members..

The thermostat 15a of the heater control is a refinement which can be dispensed with if costs are to be kept to a minimum. In such an embodiment, the supply of electric current to the heater elements will be interrupted manually when the operator considers that the two jaw members 2, 6 are at the desired temperature and will be recommenced when he considers that the temperature has dropped too low. Alternatively, the thermostat may be replaced with a timing device adapted to energise the heater for a predetermined time. In such a case, the heater may be clamped to a coupling when cold, and then be switched on. The heater will heat for a predetermined time and will then cool down again. During this time another connection may be prepared.

By widening the apparatus, or at least the jaws of the apparatus, it is possible to melt the solder of both beads of the "Yorkshire" connection simultaneously. Clearly, two medial undercuts 13a or 14a will be required for each transverse groove 13 or 14.

Instead of sliding cartridge-type heating elements into reamed holes 12, heating elements can be integrally moulded into the appropriate jaw member during manufacture.

A major modification with respect to the apparatus illustrated in the drawings is to provide one or more induction heating elements instead of the resistance heating elements described above. Such an inductive heating system functions in the normal way, a respective half of a first primary induction loop extending around each of the two arcuate grooves 13,23 defining the left-hand collar-gripping means.

When the jaw members 2, 6 are closed, suitable contacts between the jaw members cause the first induction loop to be completed so that a current can flow. A second primary loop is similarly formed around the right-hand arcuate grooves 14, 24.

However, because the jaws of such an induction heating apparatus need not contact the collar of the connection, only one pair of arcuate grooves 13, 23 or 14, 24 need be provided for the apparatus to be useful with many different diameters of pipe and the undercuts 13a, 14a can be dispensed with. Clearly, the heater control 15 can also be dispensed with and, instead, it may be convenient to provide some form of switch on the apparatus, for example in the form of a trigger, so that current can be supplied to the induction loops for just as long as the operator considers necessary to melt the solder in the "Yorkshire" connection.

Claims (20)

1. An apparatus for soldering a first member, provided with a soldering alloy, to a second member, the apparatus comprising two jaws, movable relative to each other and movable to a position in which they surround, or at least partly surround, the first member, and a heating means formed integrally with or directly associated with at least one of the said jaws to heat the first member.

2. An apparatus according to claim 1 wherein the jaws are respectively adapted to surround first members of differing sizes.

3. An apparatus according to claim 1 or 2 wherein the heating means is electrically operated.

4. An apparatus according to any one of the preceding claims wherein the second member is a pipe and the or each first member is a collar connection of the "Yorkshire" type comprising beads filled with solder.

5. An apparatus according to claim 4 wherein the jaws each comprise at least one groove to accommodate such a bead.

6. An apparatus according to any one of the preceding claims wherein there are two opposed said jaws hinged to each other, the arrangement being such that the jaws may be opened to accommodate the first member and then closed.

7. An apparatus according to any one of the preceding claims wherein the apparatus comprises two handles. so arranaed and so linked to the iaws as to provide an automatic clamping action as the jaws are closed.

8. An apparatus according to claim 7 wherein, to provide such an automatic clamping action, a first said jaw has a lever portion angled away from an abutment region of the second said jaw, there being a locking member hinged to the said lever portion at a point remote from the said first jaw and adapted to engage the said abutment region to provide an over dead centre action.

9. An apparatus according to any one of the preceding claims wherein the heating means comprises at least one electrical resistance heating element which may be embedded in the material of one or both of the said jaws, or may be located within a hole or holes formed within one or both of the said jaws.

10. An apparatus according to any one of the preceding claims wherein the jaws are each made of a metal, such as aluminium, to conduct heat from the heating means.

11. An apparatus according to any one of the preceding claims wherein a thermostatic control means is provided to regulate the temperature of the jaws.

12. An apparatus according to any one claims 1 to 10 wherein a timing means is provided to time the duration of heat production.

13. An apparatus according to any one of the preceding claims comprising heat-insulated handles to assist manual operation.

14. An apparatus according to claim 13 wherein air gaps are provided between the handles and the remainder of the apparatus to hinder the conduction of heat from the heating means to the handles.

15. An apparatus according to any one of claims 1 to 8 wherein the heating means comprises one or more electrical induction elements, so arranged in the jaws that, in operation of the device, the "Yorkshire" connection is heated evenly around substantially all of its periphery.

16. A method of joining two pipes to one another in end-to-end abutment by use of a "Yorkshire" type collar connection, the method comprising the steps of sliding approximately half of the collar over the end of one said pipe, passing the end of the other said pipe into the collar to abut end-to-end with the first said pipe and, simultaneously or successively, encompassing at least partly the periphery of the collar surrounding one said pipe with jaws and heating the encompassed part of the collar, with heating means formed integrally with or directly associated with or constituted by one of the said jaws, to melt solder contained within that part of the collar, thereby to seal the collar to the said pipe, and also effectively the said encompassing and heating steps with respect to the part of the collar surrounding the second said pipe.

17. A soldering apparatus substantially as described herein with reference to, and as shown in, the accompanying drawings.

18. A method of soldering a first member to a second member substantially as described herein with reference to the accompanying drawings.

19. Two oioes whenever ioined substantiallv end-to-end by a "Yorkshire" type connection, using an apparatus or method according to any one of the preceding claims.

20. Any novel feature or combination of features disclosed herein.