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Title:
EQUIPMENT FOR USE IN PLASTICS PIPE WELDING
Document Type and Number:
WIPO Patent Application WO/2015/028775
Kind Code:
A1
Abstract:
A portable butt fusion machine for fusing plastics pipes at a height of greater than one metre above floor level comprises: first and second frame members for attaching to ends of respective first and second pipes said first and second frame members being slideably moveably with respect to each other; a transport mechanism for urging said first and second frame members towards and away from each other; means for attaching said first and second frame members to said ends of said first and second pipes, such that the frame members can be urged towards and away from each other whilst being suspended by said first and second pipes and/ or a support rail located adjacent said pipes.

Inventors:
BRAMHALL MARTYN (GB)
CRISTOBO-GIADAS ROSARIO (GB)
Application Number:
PCT/GB2014/000338
Publication Date:
March 05, 2015
Filing Date:
August 29, 2014
Export Citation:
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Assignee:
FULLFLOW GROUP LTD (GB)
BRAMHALL MARTYN (GB)
CRISTOBO-GIADAS ROSARIO (GB)
International Classes:
E04D13/08; B25B5/14; B29C65/20; B29C65/78; F16L47/02
Foreign References:
DE20304074U12003-06-26
EP0167870A21986-01-15
JP2005231200A2005-09-02
GB2191976A1987-12-31
EP0965439A21999-12-22
EP0535454A21993-04-07
DE202006003138U12006-11-09
DE2153007A11972-05-25
Attorney, Agent or Firm:
FRANKS & CO LIMITED et al. (Brightside LaneSheffield,South Yorkshire, S9 2RX, GB)
Download PDF:
Claims:
Claims

1. A portable butt fusion welding machine for fusing plastics pipes at a height of greater than one metre above floor level, said apparatus comprising:

5

first and second frame members for attaching to ends of respective first and second pipes said first and second frame members being moveable with respect to each other; 0 a transport mechanism for urging said first and second frame members towards and away from each other; means for attaching said first and second frame members to said ends of said first and second pipes, such that the frame members can be urged towards5 and away from each other whilst being suspended by said first and second pipes and/ or a support rail positioned adjacent said pipes.

2. The portable butt fusion welding machine according to claim 1 , further comprising means for suspending said frame members from said support o rail positioned adjacent said pipes.

3. The portable butt fusion welding machine according to claim 2, wherein said means for suspending said frame members from said support rail is height adjustable relative to said frame members.

5

4. The portable butt fusion welding machine according to any one of the preceding claims wherein said transport mechanism comprises at least one rotatable threaded bar arranged to rotate about an axis which is parallel to a direction of movement of said first and/or second frame members towards or o away from each other.

5. The portable butt fusion welding machine according to any one of the preceding claims, wherein said transport mechanism comprises first and second bars or rails, along which at least one of said first and/or second frames can move towards or away from said other one of said first or second frames.

6. The portable butt fusion welding machine according to claim 5, wherein said first or second frame member is held by at least one carriage which is capable of running along said first and second bars or rails. 7. The portable butt fusion welding machine according to claim 6, wherein said first and second rails each comprise an upper and lower substantially "V" shaped track along which said at least one carriage runs.

8. The portable butt fusion welding machine according to claim 6 or 7, wherein said carriage comprises a set of wheels or rollers which run along said first and second bars or rails.

9. The portable butt fusion welding machine according to claim 8, wherein each said wheel comprises a substantially "V" shaped circular groove.

10. The portable butt fusion welding machine according to any one of the preceding claims comprising a stepper motor drive for controllably urging said first and second frames towards and away from each other. 11. The portable butt fusion welding machine according to any one of the preceding claims wherein a said means for attaching said frame members to said pipe ends comprises at least one strap attachable to a said frame member and a mechanism for tightening said strap. 12. The portable butt fusion welding machine according to any one of claims 1 to 5, wherein said means for attaching said frame members to said pipe ends comprises at least one chain.

13. The portable butt fusion welding machine according to any one of claims 1 to 5, wherein said means for attaching said frame members to said pipe ends comprises a mechanical clamping arrangement.

14. The portable butt fusion welding machine according to any one of the preceding claims wherein each said frame member comprises a trough portion suitable for seating a respective said pipe in said frame member. 15. The portable butt fusion welding machine according to any one of the preceding claims manufactured from a metal, a metal alloy, a plastics material, or a carbon fibre/ aluminium composite material.

16. The portable butt fusion welding machine as claimed in any one of the preceding claims capable of being lifted to chest height by either one person of average build alone, or by two persons of average build, without the need for any mechanical handling equipment.

17. The portable butt fusion welding machine as claimed in any one of the preceding claims comprising a pressure or force sensor for measuring the pressure or force at which the two frames are urged together.

18. The portable butt fusion welding machine as claimed in any one of the preceding claims further comprising an electronic control means for controlling movement of said first and second frames.

19. The portable butt fusion welding machine as claimed in claim 18, wherein said control means is configured to control: a distance between said first and second frames; a force applied to said first and second pipes by said first and second frames; and a time period over which said force is applied by said first and second 5 frames.

20. A portable pipe connecting machine for connecting first and second pipes together in an axially aligned manner, said machine comprising: l o first and second frame members; first and second attachment means for attaching said first and second frame members to a respective first and second pipe pieces;

15 first and second rails extending between said first and second frame members, for holding said first and second frame members in rigid alignment in a first direction, whilst allowing said first and second frame members to move towards and away from each other in a second direction, said second direction being perpendicular to said first direction; and

20

a controllable powered means -or urging said first and second frames towards and away from each other; wherein

25

said first and second attachment means are capable of supporting said machine from said first and second pipe pieces without the need for any further support.

30 21. The portable pipe connecting machine as claimed in claim 20, wherein said second frame is carried by first and second carriages, on said rails.

22. The portable pipe connecting machine as claimed in claim 21 , wherein said first and second carriages each comprise a set of rollers, each roller comprising a concave groove around a circumference of said roller. 23. The portable pipe connecting machine as claimed in any one of claims 20 to 22, wherein said first and second rails each have at least one convex surface.

24. A method of end to end connecting of pipes at elevated height, said method comprising: raising first and second frame members underneath said pipes; suspending said first and second frame members from said pipes and/ or from a support rail positioned adjacent said pipes; securely attaching said first and second frame members to said respective first and second pipes; heating the ends of said first and second pipes to melt or partially melt the ends of said first and second pipes; urging said first and second frame members towards each other such that said first and second pipe ends are pressed together; and fusing said pipes together; and removing said first and second frame members from said pipes. 25. The method as claimed in claim 24, wherein said first and second frame members are urged towards each other along a direction substantially parallel to a main common central axis of said first and second pipes.

26. The method according to claim 24 or 25, wherein said first and second pipe support members are urged towards each other and/or apart from each other by means of a rotatable threaded bar.

27. The method according to any one of claims 24 to 26, comprising controlling a pressure at which said pipes are urged together.

28. The method according to claim 24, further comprising controlling a duration over which said pressure is applied to said pipes.

29. The method according to any one of claims 24 to 28, further comprising controlling the temperature of a heated plate which is inserted between said frame members.

Description:
EQUIPMENT FOR USE IN PLASTICS PIPE WELDING

Field of the Invention

[0001] The present invention relates to equipment for use in the butt fusion of plastics piping, and particularly although not exclusively to the butt fusion welding of suspended plastics piping.

Background of the Invention

[0002] Conventional roof drainage systems for buildings, for example syphonic drainage systems, comprise a plurality of rain water gulleys, troughs or ponding areas which drain water from an adjacent roof, the troughs, gulleys or ponding areas being drained by one or more syphonic drain outlets which feed into a system of piping, underneath the roof. Where utilised, typically, the piping drainage system will be suspended from a set of suspension rails within the building, which are themselves attached or suspended to rigid parts of the building, such as an internal metal frame structure. In other installations, the pipes may be attached to a building by rods or brackets or other fixings without a suspension rail. The suspended rails are rigid enough to allow accurate and secure suspension of the rain water drainage pipes, to carry water to one or more downpipes and to an external drain.

[0003] Referring to Figure 1 herein, there is illustrated schematically in view from one side, a typical known horizontal rain water drainage pipe 1 suspended within a building. The assembly comprises first and second rainwater pipes 2, 3 connected by a collar type connector 4, each rainwater pipe being suspended from an overhead rail 5 by a plurality of circular brackets 6,7. The rail 5 is suspended from a rigid structure of the building, for example a metal frame, by a plurality of adjustable tie rods 8 - 10. Each circular bracket is itself height adjustable relative to the support rail 5, by virtue of being suspended by an adjustable screw thread and lock nut arrangement extending between the circular bracket and the rail, which can be set to a specified length. [0004] To assemble a rain water pipe drainage system in a building, first of all the suspension rails need to be attached to rigid supporting parts of the building structure, which in the case of a steel case framed building may be parts of the steel frame, and the rain water pipes need to be elevated from the ground to a position underneath the roof, and suspended from the rails. In some situations, the complete pipe network cannot be assembled at ground level and raised to height, because it is too heavy and long. Therefore, assembly of individual pipe sections needs to take place at height to create the suspended pipe network. Typically, this involves a team of men with one or more motorised hydraulically powered gantries of the "cherry picker" type, raising the pipes up to roof level, attaching suspension brackets around the pipe and to the suspension rail, and then joining the ends of pipe together at height. In some buildings, roofs can be of a significant height, and safety of personnel is a primary concern when manipulating pipes at such heights above ground level.

[0005] Roof level rainwater conveyance piping is located generally horizontally, and the tendency for the piping to sag not only due to its own weight, but more significantly to the weight of rainwater being conveyed, is countered by the provision of band clamps by which the length of piping is attached to a metallic support rail extending parallel to the longitudinal axis of the pipe length, corresponding generally in length to that of the length of pipe, and slightly spaced from the external periphery of the piping, with the support rail itself being attached to the structure of the building involved. [0006] Referring to Figure 2 herein, once individual lengths of pipe have been suspended, conventionally pipe sections are joined in situ using a cylindrical pipe connector as shown in Figure 2 herein. The pipe connector 200 comprises a cylindrical tube 201 , having a set of internal copper conductors, through which an electrical current can be passed via a pair of electrical connectors 202, 203. In use, two ends of a pipe are inserted into the connector, abutting end to end within the connector, and an electrical charge is passed through the conductors, which results in fusing of the plastics of the connector tube around the outside of the two plastic pipes, thereby melting the outer surfaces of the pipes and- welding them to the internal surface of the pipe connector.

[0007] However, this system is prone to leakage problems, where the metal conductor does not uniformly melt the inside of the connector to the outside surface of the piping. Further, it is not always easy to see where leaks occur. The system is particularly prone to leakage where the two end to end pipes are not aligned accurately along a main central axis, but there is a slight angle of offset, causing the pipes to become skewed within the connector. The system requires accurate alignment of the pipes to ensure a leak free joint.

[0008] In addition, each connector is an additional component in the pipe network and therefore adds cost to the overall pipe system. [0009] For ground based polyethylene piping in other applications, such as gas or water services, it is known to butt weld polyethylene pipes at ground level, or within underground trenching, using a butt welding machine. Pipes can be joined in the field using butt welding techniques. The piping is initially supplied in transportable and manually handleable lengths of for example 6m, which then require end-to-end connection by the butt fusion technique, in which the two pipes are clamped adjacent their ends in a butt fusion machine and a heater plate is introduced into a gap between the pipe ends for a prescribed heating period, the heating plate then being removed, and the pipe ends butted together and retained for a prescribed cooling period, to make a satisfactory joint.

[0010] To enable a butt fusion machine to handle a range of different piping diameters a suite of exchangeable inserts are provided having an arcuate, pipe engagement surface appropriate for the diameter of piping involved.

[0011] Referring to Figure 3 herein, there is illustrated schematically a prior art plastics pipe butt welding machine. The machine comprises a frame assembly 300 having a plurality of breakable "O" rings 301 - 304, each of which can be separated into two semi-circular halves, to fit the device around the ends of two pipes; a transport mechanism for urging a first set of O rings 30T, 302 towards or away from a second set of said O rings 303, 304 ~ under hydraulic pressure; an hydraulic pump and control device 305 for operating and powering the transport mechanism; and an electrically heated plate machine 306 comprising a frame holding a heatable plate.

[0012] In use, a first pipe is surrounded by a first and second pipe clamps 301 , 302 which clamp around one end of the first pipe, and a second pipe is inserted into the two other clamp rings 304, 305.

[0013] The two pipes are positioned end to end, and the heated plate mechanism 306 is inserted between the pipe ends. The pipe ends are moved to the heated plate suing the transport mechanism, to melt the ends of the pipes. The heated plate mechanism 306 is then lifted out, and the pipes are urged together by the clamping assembly, under hydraulic pressure provided by the hydraulic pump system 305. Once the two pipes are welded together, the halves of the O rings are separated, and the O ring assembly is removed from the pipe, leaving a butt welded joint.

[0014] Whilst operating at ground level, the dimensions and weight of the known butt fusion machine are not critical. However, known butt welding machines cannot be used for piping intended for the conveyance of rainwater, which is conventionally located at roof level requiring the elevation and handling of a machine at roof level because of the weight and bulk of the machines, and the need to provide safe operations at height, and comply with health and safety regulations.

[00 5] Particularly for the larger diameters of pipe, operation at roof level is unsuitable for using known butt welding equipment. [0016] One object of specific embodiments according to the present invention is the provision of improved equipment for use in the butt fusion of plastics piping, particularly, although not exclusively, for suspended rain water piping systems.

Summary of the Invention

[0017] According to one aspect there is provided a portable fusion welding machine for fusing plastics pipes at a height of greater than one metre above floor level, said apparatus comprising: first and second frame members for attaching to ends of respective first and second pipes said first and second frame members being moveable with respect to each other; a transport mechanism for urging said first and second frame members towards and away from each other; means for attaching said first and second frame members to said ends of said first and second pipes, such that the frame members can be urged towards and away from each other whilst being suspended by said first and second pipes, and/or a support rail positioned adjacent said pipes.

[0018] Specific embodiments may be capable of welding plastic pipes to industry, national and international standards currently in force.

[0019] Specific embodiments may provide equipment for use in the butt fusion of plastics piping of the type intended for the conveyance of rainwater that, in use, is suspended in a generally horizontal disposition, via metallic band clamps, from a metal support rail. The equipment comprising a pair of spaced- apart support arms, generally of "C" profile, with an upper portion of each arm being recessed so that it is, in use, manually engageable on the metal support rail, at a location where a butt joint between adjacent pipe ends is required, to temporarily suspend the equipment from the support rail, and with a lower portion of each arm defining a seating to receive, in use, a lower portion of a pipe end, with a flexible clamping means adapted, in use, to be connected to each arm and to extend over a top surface of a pipe, one of the arms being axially moveable with respect to the other of the arms under the control of a positional adjustment means, and the non-movable arm carrying a pair of parallel guide rods along which the moveable arm is advanceable and retractable upon user activation of the positional adjustment means. In alternative configurations the piping may be supported by metallic bands which are secured to an adjacent wall or ceiling, or a rigid member such as a support rail underneath the pipes.

[0020] Other aspects are as set out in the claims herein.

Brief Description of the Drawings

[0021] For a better understanding of the invention and to show how the same may be carried into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings in which: Figure 1 herein illustrates schematically in view from one side, part of a suspended rain water piping system, joined by a known electro-fusion collar connector;

Figure 2 herein illustrates schematically a known electro-fusion collar pipe connector connecting first and second rain water pipes;

Figure 3 herein illustrates schematically a known butt fusion connector system for use at ground level for connecting surface or underground plastics water supply pipes, drainage pipes or gas pipes;

Figure 4 herein illustrates schematically a pipe connecting apparatus for connecting suspended plastics pipe sections; Figure & herein illustrates schematically the pipe connector apparatus of Figure 4, suspended from a pipe suspension rail during a pipe connection operation;

Figure 6 illustrates schematically a releasable restraining strap for securing a pipe to a part of the pipe connector apparatus;

Figure 7 illustrates schematically the pipe connector apparatus of Figure 4 suspended from first and second pipes which are being connected during a pipe connection operation;

Figure 8 illustrates schematically a section of pipe which is butt welded using the apparatus of figures 4 to 7 herein;

Figure 9 herein illustrates schematically a second embodiment portable butt fusion machine as viewed from the front, showing a stepper motor controlled transport mechanism; Figure 10 herein illustrates schematically a plot of distance between frames against time for a computer controlled variant of the second embodiment portable butt fusion machine during a computer controlled pipe connecting operation;

Figure 1 1 herein illustrates schematically in perspective view from above and one side a third portable butt fusion apparatus according to a third specific embodiment;

Figure 12 herein illustrates schematically the third butt fusion apparatus in view from one end; and

Figure 13 herein illustrates schematically the third butt fusion apparatus in view from above. Detailed Description of the Embodiments

[0022] There will now be described by way of example a specific mode contemplated by the inventors. In the following description numerous specific details are set forth in order to provide a thorough understanding. It will be apparent however, to one skilled in the art, that the present invention may be _ practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the description.

[0023] In this specification, the term "portable" when used in relation to a pipe welding machine or butt fusion machine is used to mean a machine which is manually portable / can be picked up by either one person alone, or by two persons without the need for any mechanical handling equipment. The machine is light enough and small enough to be picked up by one or two persons, and can be lifted at least to chest height by a single person or two persons of average build.

[0024] The following embodiments are aimed at fusing plastics pipes which are positioned or located at a height above floor level of one meter or greater, and as such are unsuitable for joining on the floor. The pipes may be suspended from a supporting overhead rail in some installations, or in other installations, may be supported by brackets either underneath the pipes, or extending laterally at the side of the pipes to attach the pipes to an adjacent wall or structural beam. The supporting rail need not always be present.

[0025] In all cases, a portable butt fusion machine as described herein may be lifted, either manually or preferably with mechanical assistance, to a height above floor level at which the pipes are located. The floor level may be the nearest floor to the pipes which is capable of supporting one or more persons, and/ or from which a mechanical handling equipment such as a fork lift truck or a "cherry picker" type mobile hydraulic lift can be operated. Such floors may include a ground floor, an intermediate floor such as in a multi storey building, or an underground floor, such as in underground building, where there is a pipe or pipes located above floor level, which require joining. onstruction

[0026] Referring to Figure 4 herein, there is illustrated schematically in perspective view a roof level portable butt fusion machine according to a specific embodiment of the present invention. [0027] The portable butt fusion machine comprises a pair of spaced apart pipe support frame members or cradles 401 , 402; and one or a plurality of bars or rails 403, connecting the first and second support members.

[0028] Each support frame comprises a base plate assembly 404, 405 respectively, and a hook assembly 406, 407 respectively.

[0029] Each base plate assembly comprises a pair of parallel upright base plates 408, 409; 410, 411 spaced apart from each other and connected together by one or more welded plates. The base assembly is cradle shaped, having a curved or "V" shaped valley or trough into which a pipe may be positioned, and such that the pipe self - centers into the valley. Extending in a direction transverse to the vertical and substantially tangential to the pipe surfaces in use, are provided a plurality of support plates 412 - 419 on the upright base plates, which support the sides of the pipes in use, and giving the sides of the pipes a larger area of support so as to distribute any pressure exerted by the portable butt fusion machine on the sides of the pipes, when the pipes are located in the troughs in the base assemblies. The support plates may be covered in a flexible material, such as rubber sheeting, to assist seating of the frames to the pipe ends.

[0030] The front portions of the base assemblies are each provided with an overhanging front slot or hook 420, 421 ; 422, 423 formed in the upright plates into which a horizontal rod can be inserted for anchoring a strap or band, to tighten around a pipe section in the trough, and retain the pipe in the trough.

[0031] The upright hook assemblies 406, 407 each comprise a pair of 5 spaced apart adjustable upright substantially "L" or "J" shaped hook portions 424,425; 426,427. Each hook portion of a hook assembly has a lower part which is slideably connected to the respective base assembly, for example by a slot and tightening rod assembly, so that the distance of the overhanging upper hook above the base assembly can be varied relative to the base assembly. The hook 10 assemblies also comprise a set of rear strap receiving slots 428, 429; 430, 431 for receiving a pair of ratchet tightening straps for securing the frame to the pipes.

[0032] In alternative embodiments, the attachment means for attaching the pipe to the frames may comprise a hinged clamp which is hingedly attached at

15 the front of the frames nearest the operator, and which can be swung over the pipes to connect to a rear portion of the frames, rigidly securing the pipes within the frames. Clamps may be lined with a resilient material, for example rubber or plastics material, so as to help grip the pipe, and to provide some tension in the clamp, to rigidly secure the pipes and stop them slipping in an axial direction, as

20 the frames move towards and away from each other. In other embodiments, the means for attaching the frames to the pipes may comprise a chain, which can be tightened by a chain tensioner fitted to the frame.

[0033] The resulting support cradles each provide a light weight but rigid 25 cradle for attachment to a respective pipe end. The upright hook portions 408 - 411 are adjustably connected to the respective base plate assemblies. The height of the overhanging hook portions above the troughs cah be varied and locked, by tightening a screw handle 432, 433 which tightens a bar through the ~ - _ base assembly and the lower part of the hook assembly, to releasably lock the 30 position of the hook assembly to the base assembly. [0034] In this manually operated embodiment, the transport mechanism _ for moving the cradles towards and away from each other comprises the one or plurality of bars or rods or rectangular rods between the cradles 40†, 402, and a rotatable threaded bar between the cradles. The cradles are moved towards and away from each other by manual rotation of the screw threaded bar in a clockwise or anticlockwise direction to urge the cradles towards each other or away from each other. In one embodiment, a pair of smooth cylindrical spaced apart bars or rods or rectangular rods, either side of the threaded bar may be inserted through a set of apertures or guides in the frames, and which allow one frame member to slide laterally towards and away from the other frame member in the general direction parallel to a main length direction of the adjacent pipes, with the distance between the frames and the pressure exerted by the frames on the pipe ends being controlled by the rotation of the threaded bar. Operation of the Portable Butt Fusion Machine

[0035] The pipe connection operation starts with first and second pipes suspended in a building, typically by a set of circular brackets as shown in Figures 1 and 4 herein. [0036] In a first mode of installation, the pipes are installed manually by operatives, by attaching the rail to a frame of a building, and attaching the openable circular brackets to the rail. A pipe is held in the circular brackets, and the ends of the circular bracket are closed using a bolt. The nuts on the down rods are tightened to secure the pipes in place. A similar operation is performed for an adjacent length of pipe. The two ends of pipe are adjacent and touching or near touching each other, but are not yet welded together. The butt welding apparatus is then used to weld the two pipe ends together.

[0037] Alternatively, a pre-fabricated modular pipe and rail system may be supplied and joined on site using the presently disclosed apparatus. In this installation method, the overhead rail, pipe brackets suspended from drop rods, and pipes are all pre-assembled in a factory and delivered on site as a modules. Typically the modules may include pipes- in 6m lengths. and the lengths are coded with unique numbers for installation in specific locations. The operatives attach the modules to the building one at a~time at the locations specified by the coded numbers, with the ends of the pipes of one module abutting the end of the adjacent module. The ends are butt welded, before the next module is installed. The next module is butt welded to the previously installed module, and then another module is installed.

[0038] Irrespective of whether the pipes are fitted to the building by the first method as above or using the modular method, joining of the pipe ends using the butt fusion machine is by the same method as follows:

[0039] The portable butt fusion machine is lifted to a position underneath the pipes, within the cage of a raiseable platform device, for example a wheeled "cherry picker" type device used for working at height. Typically, the platform of such devices is surrounded by a metal rail, to avoid operatives falling off the platform. The size, dimensions and weight of the pipe connector device are typically within around 1 m 3 , and in this embodiment example having dimensions in the range:

Height: 600mm - 800mm

Width (whole device): 800mm - 1200mm

Depth: 400mm - 700mm [0040] The apparatus can be manually lifted by one or two persons standing hydraulically raised platform, for example of the "cherry picker" type, is light enough and small enough to be manually maneuvered at chest height to hook the device direct on to a pair of pipes, or onto a rail above the pipes. Having raised the pipe connector to a position underneath the pipes, the manual operatives can either manually lift the device and hook it over the rail, or pipe if a rail is not being used, or using the hydraulic controls of the gantry, can use the gantry to lift the device up, and then manually pull the hook portions over the rail, so that the portable-butt fusion machine is suspended from the pipe or from the overhead rail.

[0041] Leaving the weight of the portable butt fusion machine suspended by the rail or pipe, the operatives can place a pair of straps, one per frame over the pipes, and then tighten up the straps using the ratchet, which lifts the frames, with the weight being taken by the pipe, and the overhanging hook portions being raised above the rail. [0042] The portable butt fusion machine is supported by the ends of the two adjacent pipes, one frame being supported by each pipe, and each pipe is supported by its own circular brackets hanging from the rail or building structure. The ratchets can be tightened up so that each frame securely grips its corresponding pipe end. The pipes can be moved apart from each other by movement of the transport mechanism of the pipe connector by turning the threaded rod slides the pipe ends towards or away from each other, depending upon the direction of rotation of the threaded rod. Any movement in the axial direction is taken up by a slight bending of the drop rods carrying the pipe, the brackets remaining rigidly secured around the pipe. The required axial separation between adjacent pipe ends to fit the heating plate in is typically of the order of 25mm to 40mm. The pipe which presents the least resistance will be the one which is moved most in the axial direction, which usually will be the more recently added pipe at the end of the pipe run which has already been welded together. [0043] The pipes are moved apart from each other, and a heated plate is inserted between the pipes to melt the ends of the pipes. Once the ends of the pipes are up to a sufficient temperature for a sufficient time, the heated plate can be removed, and the transport mechanism of the pipe connector is used to urge the ends of the pipe towards each other, so that the hot ends of the pipe bond with each other under sufficient pressure and for sufficient time, and form a butt weld. [0044] After the butt weld is completed and has cooled sufficiently to be set, the ratchet straps on each of the frames can be released, and the pipe ^connector then drops vertically such that the hook portions rest on the rail or pipe and the pipe connector is hanging from the rail or pipe.

[0045] With the straps removed, the operative may then lift the mechanical handling equipment gantry up underneath the base portions of the frames to take the weight of the frames, lifting the hook portions up and then out in a direction away from the pipe, to remove the pipe connector altogether. Alternatively the operator may manually unhook the device.

[0046] Referring to Figure 5 herein, there is illustrated schematically the portable butt fusion machine in use during a second stage of operation. After having lifted the portable butt fusion machine apparatus up to roof level, underneath the pipe work, using a hydraulic gantry, a manual operators can lift the frame up, and hook the hook assemblies 406, 407 over the suspended rail which supports the pipes. In this position, the operators are relieved of the weight of the portable butt fusion machine, since its weight is supported by the rail, or by the pipe where no supporting rail is present.

[0047] From this position, the operators can attach a ratchet strap as shown in Figure 6 herein between the front ratchet strap receiving slots and the rear ratchet receiving slots so that each pipe is secured to a respective support member by a separate ratchet strap.

[0048] As the ratchets are tightened up, the pipes themselves take the weight of the frames, so that when the ratchet straps are fully tightened, the cradles are lifted underneath the pipes, and the pipes sit in the troughs of the cradles, tightly secured by the respective ratchets.

[0049] Each support frame 401 , 402 is tightly secured to a respective pipe end. The two support frames are in spaced apart relationship to each other at a distance specified by the transport mechanism. The operators can then urge the pipes away from each other by extending the transport mechanism so that the first frame is urged apart from the second frame, by turning the threaded rod. [0050] A heated plate is then positioned between the ends of the pipes, the heated plate being held substantially vertically, so that both ends of the pipe are melted or partly melted. When the-ends of the pipes have been heated to sufficiently high temperature so as to become partially fluid, the transport mechanism is operated to move the wo frames apart from each other slightly, each carrying their respect pipe, leaving enough room for the heated plate to be removed by the operators.

[0051] This leaves the two hot ends of the pipe facing each other and aligned with each other axially, held by the first and second frames.

[0052] The operator then tightens the threaded bars on the transport mechanism, which can be done either manually or using a power tool, for example an electric drill with an attachment, so as to urge the two frames together, thereby urging the two ends of the pipe together which are still hot.

[0053] Pushing the two ends of the pipe together results in a butt weld one example of which is as shown in Figure 8 herein.

[0054] Referring to Figure 6 herein, there is illustrated schematically one example of a ratchet strap used for securing the frame to the pipes. The ratchet strap comprises a first end 600 having a bolt or bar 601 passing through an eye of the strap, which is formed by looping the strap onto itself, and sewing one end of the strap to a position further along the strap. At a forward end of a strap there is another loop, through which a forward bar or bolt is slid. The bolts or rods are loose, so that the bolts extend beyond the width of the straps and can be engaged with the side plates of the frame member at the front and the rear. Conventional ratchet mechanism 603 is provided joining the two ends of the strap, which can be tightened or loosened in conventional manner as will be understood by those skilled in the art. The straps may be of the "tautliner" RTM type design such as used on the side curtains of commercial vehicles. [0055] Referring to Figure 7 herein, there is illustrated schematically the two ends of the pipe which have been butt welded, with the portable butt fusion machine still attached.

[0056] Referring to figure 8 herein there is illustrated schematically two pipe ends supported by an overhead rail, brackets and tie rods, which have been welded together by a butt welding machine as described herein, following removal of the machine.

Removal of the Pipe Connector After Welding

[0057] After welding, the portable butt fusion machine remains secured to and suspended from the pipes as shown in Figure 7 herein. To remove the pipe connector, the operator releases the first and second ratchet handles 700, 701 , which allows the frame to drop, such that the overhanging hook portions drop onto the overhanging rail, and the frame is then suspended from the rail.

[0058] The operator then removes both of the first and second straps by untightening the nuts on the end of the cross bars that fit through the straps and into the forward slots of the portable butt fusion machine, thereby releasing the frame from the pipe altogether. The frame is now in a similar position as shown in Figure 5 herein, and can be manually lifted off the suspension rail or pipe, and down into the overhead "cherry picker" gantry. The gantry can then be lowered to the ground, or can be moved further along the pipe to effect a similar connection between pipes at a different position in the building. [0059] Specific embodiments disclosed herein provide a lightweight man- portable butt fusion machine frame which is small enough and light enough to be carried in an elevated platform or on other forms of elevated access such as scaffold, and to provide safe operation on a restricted elevated platform for connecting a pair of suspended pipes in a controlled manner. The portable butt fusion machine permits stable and controllable positioning of first and second pipes at height, so that the correct heated plate temperature, timing, and correct pressures for forcing the pipes together can be achieved in a controlled manner in a restricted area, without the human operators having to move their body weight outside the area of the platform, which could be dangerous at height.

Use of the Equipment

[0060] It follows that, in use, the equipment is firstly hooked onto, and suspended from, the metal support rail where present. The flexible clamping means is then wrapped over the top of the piping, adjacent the ends to be welded, and manually tightened, which has the effect of transferring the weight of the equipment from the metal support rail to the piping, so that the piping now carries the equipment rather than the metal support rail. The positional adjustment means is then operated to ensure a suitable gap exists or is created between the adjacent pipe ends for the introduction of a heater plate. After a suitable time, the heater plate is removed, and the positional adjustment means is again activated to force the pipe ends together to make the butt joint. After a prescribed time, the flexible clamping means is released so that the upper portion of the arms again engage the metal support rail, whereby the equipment is again suspended from the metal support rail. The equipment may then be manually removed to the next required location. Powered Embodiment

[0061] Referring to figure 9 herein there is illustrated schematically in view from the front, a second embodiment portable butt fusion machine. The second embodiment is substantially similar in construction to the first embodiment described herein above, except for the transport mechanism for moving the two frames towards and away from each other, which is adapted for powered operation. [00621 The second embodiment portable butt fusion machine 900 comprises first and second spaced apart frame or cradle members 901 , 902; a pair of smooth surfaced cylindrical rods or bars 903, spaced apart from each other, each bar or rod having its first end rigidly secured to the first frame member 901 , and a distal portion 904 of the rods or bars being inserted through an aperture or guide in the second frame member 902, such that the second frame member can slide in a direction along a main length of the rods or bars and towards or away from the first frame member 901 ; a drive rod or bar 905 positioned between the first and second rods 903, the drive bar having a distal end 906 rigidly secured to the second frame member 902, and a proximal end 907 passing through the first frame member 901 ; a drive motor 908 connected to a gear box or drive mechanism 909; and a control unit 910 for controlling the drive motor 908. [0063] The drive rod or bar 905 may comprise a substantially smooth cylindrical bar, having a toothed track. The drive mechanism 909 in the case where the bar has a toothed track, may comprise a gear box and gear drive for drawing the bar through the gear box in a forward to reverse direction. [0064] In a variant where the dn ' ve rod or bar 905 is a rotatable screw threaded bar, the motor and gear box 909 may be mounted on the other frame (second frame) 902, and the end of the drive rod or bar which passes through the first member may engage with a screw threaded portion in the first frame member, so as to urge the first frame member backwards and forwards relative to the second frame member. The frames may be driven towards or away from each other by powering a screw threaded bar using a stepper motor attached to one of the cradles, such that fine control of the rotation of the threaded bar can be achieved by control of the stepper motor. [0065] In either case, the drive mechanism 909 is powered by electric motor 903 which is preferably a finely controllable stepper motor, which can be controlled by the hand held control unit 910. [0066] The control unit 910 may have a forward/reverse switch which may be manually operable. Alternatively, the control unit may comprise a digital processor having a pre-stored control program for controlling operation of the stepper motor to perform a complete pipe connecting operation. There may be provided sensors within the stepper motor or drive mechanism 909 to measure force exerted on the drive bar 905 by the drive mechanism 909. The control unit also measures time so that by controlling the stepper motor, the control unit can operate a pre-programmed operation for butt welding a pair of plastic pipes, using a set of pre-determined times and pressures for urging the hot ends of the pipes together to form a water tight and robust joint.

[0067] Operation of a processor controlled variant of the powered embodiment will now be described.

[0068] Positioning and lifting of the portable butt fusion machine, connecting the pipe apparatus to the ends of first and second pipes is substantially as described with reference to the first embodiment herein. Prior to connection of the pipes, the ends of the pipe are left either slightly spaced apart, or touching each other with the circular supporting brackets left loose, so that the pipes can slide with respect to the brackets in an axial direction along the lengths of the pipe.

[0069] The portable butt fusion machine is lifted to a position underneath the pipes using a hydraulic platform device, fork lift truck, or other mechanical handling equipment suitable for and safe for working at height. Having raised the portable butt fusion machine to a position underneath the pipe, human operatives can either manually lift the device and hook it onto an overhead support rail which is supporting the pipes, where such a rail is present, or if no such rail is present, then the operatives can raise the portable butt fusion machine underneath the pipes, and secure the straps, chains or clamps as appropriate, around the pipes, so that the first and second frames are secured to respective ends of the first and second opposing pipes. As the-ends-of the pipes are firmly held by the cradles of the portable butt fusion machine, a movement of the cradles with respect to each other will slide the pipe ends towards or away from each other in an axial direction. Using the control unit, a human operator can manually move the pipes forwards or backwards, towards or away from each other, to position the pipes with a gap relative to each other or to touch each other. The remainder of the pipe movement operation can be controlled by a pre-determined program stored in the control unit.

[0070] Once the pipes are positioned by manual operation of the control unit to a pre-determined gap with respect to each other or to touch each other, an appropriate program can be selected by the operator suitable for the particular material type and size of pipe being joined. The operator then activates the control unit.

[0071] Once activated, the control unit will automatically draw apart the pipes to a pre-determined distance, to allow the operators to manually insert a hot plate between the pipes. The control unit may then be moved on to the next stage of the program by the operator pressing a button on the control unit, which causes the controller to urge the two cradles together, along with the pipe ends, so as to press the ends of the pipe onto the hot plate, with a pre-determined force and for a pre-determined duration, according to the parameters pre-set in the program for that particular type of pipe. [0072] Once the pre-set duration is expired, the controller drives the cradles or frames apart from each other so that the pipe ends are separated by a distance large enough for the operators to safely remove the hot plate. The temperature of the hot plate is monitored by the operatives, although optionally, a temperature sensor on the plate may be connected to the control unit so that the control unit will only operate once the plate has reached a temperature within a pre-determined temperature range, corresponding to the pipe type for the selected program. [0073] Once the hot plate is removed, the operator then activates the control unit again which then draws the two frames together by control of the stepper motor, urging the ends of the pipe together. The control unit presses the two ends of the pipe together, measuring the pressure via the sensors within the drive unit, and for a pre-determined duration which is enough to butt weld the two hot pipe ends together. After the pre-determined duration, the control unit will provide an alert signal, for example a red light, or a display on a liquid crystal display or light emitting diode display of the control unit, or on an associated laptop or similar computer, alerting the operators that it is safe to remove the attachment means which attach the frames to the pipes.

[0074] The operators can then lower the portable butt fusion machine as described with reference to the first embodiment, leaving the connected pipes in situ.

[0075] The control unit may be programmable so as to contain a set of programs, each program being suitable for a particular pipe type. A further stage of automation may be provided, in that instead of waiting for the operator to activate urging of the hot pipes together after the heating stage, the control unit may automatically urge the two hot ends of the pipe together after a predetermined period (which is long enough for the operators to remove the hot plate), thereby ensuring better uniformity and reproducibility of joints. [0076] Referring to Figure 10 herein, there is illustrated schematically a plot of frame position relative to each other against time for an automatically controlled jointing operation carried out by the second embodiment pipe connecting apparatus. [0077] During time period a, the pipes are in their initial configuration relative to each other at fitment of the frames. The pipes could be spaced apart slightly, or the pipe ends could be touching each other. In the example shown, the pipes are slightly spaced apart.

[0078] In time period b, the control unit and/or operator urges the ends of the two frames together so that the ends of the pipe (touch distance TD). Pressure sensors within the drive mechanism detect when the pipes have touched, and use this distance between the frames as a datum for controlling the remainder of the operation.

[0079] During time period c, the frames are moved apart for a duration long enough for the operators to insert a hot plate between the ends of the pipe, with a margin of safety. Time period c may be extended automatically by the control unit if the control unit detects that the hot plate is not within the correct temperature range. The duration c may be extended until the plate has reached the correct temperature.

[0080] The frames are then urged together so that the ends of the pipe touch the hot plate during period d. During this period, the frames are a distance HD (heating distance) from each other. During the period d, the control unit may maintain a steady pre-determined pressure, which means that as the ends of the pipe melt. There may be some movement of the frames towards each other from the initial heating distance HD. Once the period d is expired, and the ends of the pipe are hot enough, the control unit then separates the frame members during period e, which is long enough to allow the operators to remove the hot plate safely but not so long that the hot ends of the plastic pipes cool and set.

[0081] The control unit may be either activated by an operator, or may be programmed to automatically activate, to urge the two pipes together at the end of separation period e, with a pre-determined pressure, and to hold them there under that pressure for a pre-determined duration f. During this period f, the pipes weld to each other under pressure, and as the pipes are urged towards each other the frames may move slightly towards each other for an initial part of the period f, until the fusion pressure is reached. Once the pipes have had time to cool within the period f, whilst the predetermined fusion pressure is applied, the control apparatus generates a signal to the operator, which can be a green light, or a signal on a computer screen or display screen, or an audible beep indicating that the .process is finished and that it is safe for the operators to detach the attachment means so that the pipe connecting apparatus can be removed from the pipes substantially as described with reference to the first embodiment herein. [0082] Referring to figure 11 herein there is illustrated schematically a third pipe joining or butt fusion machine 1 100 according to a third specific embodiment, being a pre-production prototype.

[0083] Referring to figure 12 herein, there is shown in view from one end, the third butt fusion machine of figure 11 herein.

[0084] Referring to figure 13 herein, there is shown in plan view from above, the third butt fusion machine of figures 11 and 12 herein. [0085] The third butt fusion machine has part circular frames which can be lifted directly on to first and second pipes, and due to its light weight, need not be suspended form an overhead rail when being fitted to a pipe run, although optionally the machine could be held suspended from an overhead pipe suspension rail prior to attaching to the pipe run.

[0086] The third pipe joining machine comprises first and second spaced apart frame or cradle members 1101 , 1102; a pair of parallel rod or bars 1103, 1104 spaced apart from each other, each bar or rod having a respective first end rigidly secured to the first frame member 1101 , and the respective distal ends of the rods or bars being held securely by an end cross member 1 105; the second frame being carried on the bars by a first and a second carriages 1106, 1107 respectively so that the second frame can move towards and away from the first frame.

[0087] Each frame or cradle 1 101 , 1 102 comprises a pair of spaced apart parallel substantially flat plates 1108, 1109 and 1 1 10, 11 11 respectively. Each plate comprises a substantially part annular upper section and a substantially rectangular- lower section, the annular and rectangular sections forming a continuous plate. Each frame forms a part circular seating into which a length of cylindrical pipe fits. The first and second plates of the first frame are spaced apart from each other in a rigid assembly, held together by a plurality of spacer pieces in a welded arrangement. Similarly, the third and fourth plates of the second frame are held parallel and spaced apart from each other by a second plurality of spacer members to form the second frame assembly. The second frame is slightly narrower at its lower end compared to the first frame, so that the lower end of the second frame fits between the bars, held by the first and second carriages.

[0088] The frames are fitted with releasable straps to secure the frames to the respective pipe ends. The straps may comprise plastics, rubber or metal straps, having a releasable catch as described above and a tightening mechanism enabling manual tightening of the straps around the pipe ends.

[0089] Each carriage 1106, 1107 respectively comprises a flat substantially rectangular plate having four rollers or wheels (hereinafter referred to as rollers) which face inwardly towards the center of the machine, and which run along the parallel bars 1 103, 1 104. The rollers or wheels are each attached to the rectangular plate by a respective axle, optionally mounted in a bearing. For each pair of rollers one above and one below the bar, one of the rollers has its axle concentric with the roller, whilst the other roller has an axle, the position of which can be varied, for example on a cam in the rectangular plate, so that the distance between the pair of rollers can be varied so as to take up any slack and to allow the carriage to move along the bar freely but without any rattling or looseness and restrict the vertical movement of the bars between the pairs of rollers.

[0090] In the best mode, each bar has a cross sectional shape having a rectangular section with triangular upper and lower portions. The upper and lower portions form ridges along which the rollers, run, and run along roof shaped triangular runs, so that the bar is held between two pairs of opposing rollers, one at a first end of the rectangular carriage plate and another at a second end of the carriage plate. The rollers have a concave circular "V" shaped perimeter with a cross sectional profile which fits the convex elongate ridges of the bars or rails. This ensures that the carriage moves along the rail or bar in a linear manner without the rollers skewing, and such that the second frame always remains parallel to the first frame. The parallel bars provide the necessary strength and stiffness to keep the device rigid when holding a pair of pipes to be connected.

[0091] Transport of the second frame relative to the first frame may be by a powered screw thread arrangement, similar to the second embodiment herein. As with the second embodiment herein, the drive rod or bar 905 may comprise a substantially smooth cylindrical bar, having a toothed track. The drive mechanism in the case where the bar has a toothed track, may comprise a gear box and gear drive for drawing the bar through the gear box in a forward to reverse direction.

[0092] In a variant where the drive rod or bar 905 is a rotatable screw threaded bar, the motor and gear box may be mounted on the first frame or on the second frame, or alternatively, on the cross member 1105. The end of the drive rod or bar which passes through the first member may engage with a screw threaded portion in the first frame member, so as to urge the first frame member backwards and forwards relative to the second frame member. The frames may be driven towards or away from each other by powering a screw threaded bar using a stepper motor such that fine control of the rotation of the threaded bar can be achieved by control of the stepper motor. The drive mechanism may be powered by an electric motor, and preferably by a finely controllable stepper motor, which can be controlled by a hand held control unit. The control unit may have a forward/reverse switch which may be manually operable. Alternatively, the control unit may comprise a digital processor having a pre-stored control program - for controlling operation of the stepper motor to perform a complete pipe connecting operation. There may be provided sensors within the stepper motor or drive mechanism to measure force exerted on the drive bar 905 by the drive mechanism. The control unit also measures time so that by controlling the stepper motor, the control unit can operate a pre-programmed operation for butt welding a pair of plastic pipes, using a set of pre-determined times and pressures for urging the hot ends of the pipes together to form a water tight and robust joint as described herein before with respect to the second embodiment.

[0093] The arrangement of "V" groove rollers and a "V" shaped rail or bar may give improved rigidity, greater durability, easier maintenance and reduced cost. It may also allow the machine to be kept compact, and to have low weight, for example less than 20kg.The upper and lower opposing "V" groove rollers may be adjustable in spacing between the rollers of an opposing pair on the same carnage, to accommodate different depths of track, rail or bar 1 103, 1104. They may also be easy to keep clean and/ or operation is tolerant of dirt build up.

Use of the third embodiment

[0094] Use of the third embodiment in relation to a run of pre-assembled pipe modules comprising pipes, rails and brackets manufactured off site and already delivered and fitted to a building will now be described. In use, the third embodiment is lifted up to a pair of pre fitted pipe modules having pipes to be joined which are suspended from a set of brackets direct to a wall, or from an overhead support rail or beam, at a height above the floor of up to 4 or 5 metres using a mechanical lifting equipment to raise the operatives and the butt fusion apparatus, similarly as described hereinbefore with reference to the first and second embodiments. The modules are installed with the ends of the pipes of adjacent modules being in end to end abutment, but not yet welded together. Since the machine is relatively light weight, a single operative can manually lift the device to hook the overhanging arm portions of the frames over the ends of the first and second pipes. The straps are then passed around the pipe ends to secure the respective first and second pipe ends to the respective first and second frames, so that each pipe cannot slip in a direction axial to the pipe.

[0095] With the straps secured, the third machine can be operated similarly to the second machine described hereinabove, by urging the two frames towards and away from each other in a predetermined computer controlled sequence of movements. Where a pipe length is being fitted to another longer run of pipe, the drop rods of the shorter run of pipe will predominantly take up any movement in the axial direction, to allow the pipe ends to be separated enough to slide the heated plate between them.

[0096] The above embodiments may have optional variations as described below.

[0097] The above embodiments may be constructed in lightweight material(s) for ease of handling and transport, such as aluminium alloy and/or synthetic plastics, with or without metallic reinforcement. These may include for example, titanium, aluminium, alloys of aluminium, glass reinforced plastic (GRP), carbon fibre, and carbon fibre/aluminium composites, and like materials.

[0098] A recess may be provided in each upper portion of each arm, of a profile matching that of the rail e.g. the recess is a square V-shaped notch if the rail is of rectangular section.

[0099] The seating surface of the lower portion of each arm is arcuate.

[0100] The seating surface of the lower portion of each arm may also be provided by a pair of mutually inclined surfaces, together defining a shallow "V".

[0101] The flexible clamping means may comprise a band e.g. of nylon. [0102] The flexible clamping means may be a chain.

[0103] " The flexible clamping means may incorporate a manually operable tightening device such as a ratchet device or screw to tighten the band, or chain around the upper surface of the pipe, so as to transfer the weight of the equipment from the rail, to the piping.

[0104] Each arm may be provided with an anchor point for a rear end of the flexible clamping means.

[0105] Each arm may comprise a pair of parallel profiled plates secured together in spaced-apart relationship. [0106] Between the plates of each arm, at a rear of each arm, extends a transverse pin serving as the anchor point for the rear end of the flexible device.

[0107] Forward ends of the plates of each arm are notched, to receive opposite ends of a removable, transverse pin serving as an anchor point for the other end of the flexible device.

[0108] Preferably, the positional adjustment means comprises a screw.

[0109] The screw is parallel to, and located between, the guide rods.

[0110] One end of the screw projects beyond the movable arm to terminate in a drive head.

[0111] The drive head may be hexagonal e.g. for engagement by a socket of an electric drill.