GB2240832A

GB2240832A - Pipe-handling and laying apparatus

Info

Publication number: GB2240832A
Application number: GB9012824A
Authority: GB
Inventors: David Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-07
Filing date: 1990-06-08
Publication date: 1991-08-14
Anticipated expiration: 2010-06-08
Also published as: CA2074415A1; GB9012824D0; CA2074415C; GB2240832B

Abstract

Pipe handling and laying apparatus 1 supports a pipe on holding and support means 2, 3 and includes extendible and retractable gripping means 4 having gripping head 4a. The pipe, supported generally within area A, is brought in end-to-end relationship with another pipe to be joined thereto. Gripper head 4a is introduced into the open end of the second pipe and ram piston P of hydraulic ram H is retracted causing legs L of gripper head 4 to pivot into extended positions to grip the interior wall of the second pipe by means of gripper feet F. Further retraction of ram piston P pulls the first pipe into close relationship with the second. The apparatus may comprise releasable retainers 108 for a seal 107. Fig. 3. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO HANDLING OR LAYING PIPES This invention relates to improvements in or relating to handling or laying pipes and is more particularly but not exclusively concerned with apparatus and method for aligning and/or joining pipes in end to end relationship or simply in reliably handling or moving pipes from one place to another.

Handling and laying of pipes, more particularly large diameter (e.g. 2.4 m) concrete pipes (e.g. 2.5 m long) into the ground, tends to be a time consuming and laborious task. In order to manoeuvre one length of concrete piping in relation to another pipe already laid in the ground the first pipe may be lifted by mechanical grab/s to be man-handled into an appropriately aligned end-to-end position with the fixed pipe, the grab/s usually being supported on ropes or cables perhaps by hydraulic lifting apparatus. Once the first pipe is manoeuvred into end to end relationship with the fixed pipe a difficulty then arises in securing the two pipes together. This may be accomplished by hydraulic pipepulling means arranged on the outside of the pipes.Such pipe-pulling equipment tends to be disadvantageous because trenches which accommodate the pipes have to be wider to accommodate the pipe pulling gear, the gear is applicable to a limited range of pipe diameters (400 to 750 mm diameter); tends to interfere with the shoring-up system, and is relatively heavy, cumbersome and costly.

The heavy weight of pipe pulling equipment means that the weight of pipes which can be handled is less than might otherwise be the case. Clearly, the task of laying pipes or even in reliably and securely handling pipes (i.e.

moving pipes from one place to another) tends to be awkward and monotonous but, nevertheless, forms an essential process in the construction industry.

It is an object of the present invention to provide apparatus and method to at least alleviate some of the aforementioned or other problems involved with the laying or handling of pipes, or to more easily and/or reliably handle and/or join pipes together.

According to a first aspect of the present invention there is provided pipe handling apparatus comprising pipe holding and supporting means to hold and support a first length of piping as it is lifted and introduced towards a second length of piping, and comprising extendible and retractable grip means connected to said pipe holding and supporting means and adapted in use to grip onto the interior of the second length of piping as the first pipe is moved into the correct alignment therewith.

By this aspect of the present invention the first length of piping which is held and supported by said apparatus can be brought into correct alignment with the second length of piping in a controlled manner and joined thereto by using the extendible and retractable grip means, usually virtually completely automatically.

Thus the pipe handling apparatus including said grip means may comprise a single (portable) unit.

Preferably, the apparatus is adapted for handling pipes of varying length and/or varying size of diameter or cross-section. Advantageously, said apparatus may be designed to handle pipes of a range of diameters from about 300 mm up to about 1200 mm.

Preferably the apparatus is self-aligning so that as the first pipe is moved or pulled towards the second it is automatically aligned therewith.

The grip means may be hydraulic or pneumatic in operation, and actuation of the grip means preferably moves the pipe lengths together.

Advantageously, therefore, the first length of piping may be lifted and introduced towards the second length of pipe and joined thereto in one operation, rather than lifting the first length into position and joining the pipes (moving or pulling the pipes towards one another into interlocking, sealing relationship) by a second operation, perhaps with the aid of additional, independently-operable pipe-pulling equipment.

In one embodiment of the present invention the grip means is in an extended state while said first pipe is introduced towards said second length and is retracted, to thereby expand the diametrical dimension of a gripper head thereof to grip the interior of the second pipe.

Preferably, the pipe-holding and supporting means of the apparatus comprises a lower support beam (locatable in use within the first length of piping) having an extendible leg or legs which hold onto the interior of the first length of piping during handling of said length. The apparatus may comprise an upper beam arranged generally parallel with the lower beam and said upper beam may include a block provided with adjustable connection points or eyes for locating cables of lifting apparatus (e.g. a hydraulically operated excavator) according to the length of pipe carried. Said lower beam may house the extendible and retractable grip means which may comprise a hydraulic/pneumatic cylinder with ram piston extending generally axially or generally axially parallel to the beam (and first pipe when in use).A, or the, gripper head of the grip means may be located on said ram piston, said head preferably being arranged at a distance beyond the lower beam, at least when the grip means is in the extended state.

The gripper head may be provided with one or more retractable legs which extend (at least radially) to increase the diametrical extent of the gripper head as the grip means is retracted generally axially of the lower beam and first pipe, in use. Preferably, the gripper head legs are provided with hard rubber feet to grip securely onto the interior walling of the second length of piping to fix the position of the gripper head axially of the second length, so that continued retraction of the grip means causes the first length of piping to be pulled towards the second length.

Further advantageous features of the apparatus will be evident from the following description and drawings.

Further according to this first aspect of the present invention there is provided a method of laying a first length of piping and joining it to a second length of piping comprising: holding and supporting the first length of piping while it is lifted and introduced towards said second length of piping by pipe handling apparatus including extendible and retractable grip means; introducing said grip means into the second length of piping and actuating said grip means to grip onto the interior of said second length of piping, moving the first length of piping into correct relative alignment with said second length of piping, preferably, by further actuation of said extendible and retractable grip means.

Many other advantageous method features will be evident from the following description and drawings.

According to a second aspect of the present invention there is provided pipe handling apparatus comprising pipe holding and supporting means to hold and support a first length of piping as it is lifted and introduced towards a second length of piping, and comprising:1. retaining means for securely locating a sealing ring relative to one end of said first length of piping as said length of piping is introduced towards a second length of piping, said retaining means acting to hold the sealing ring in place while the first length of piping is joined to said second length of piping, and/or 2. spring loaded safety catches which securely locate the first length of piping on said apparatus during handling, and/or 3. a portable unit including grip means which is adapted to grip the interior of the second length of piping as the first length of piping is joined to said second length.

Advantageously, the weight of the apparatus in accordance with the present invention may be as little as 350 kg in comparison with weights of a ton for other pipe laying apparatus. The apparatus may also be produced at about one quarter of the cost.

Two embodiments of apparatus for handling and laying pipes and method of handling and laying pipes in accordance with the present invention will now be described, by way of example only, with reference to the much simplifed diagramatic drawings, not drawn to scale, in which: FIGURE 1 shows a pictorial representation of the first embodiment of said apparatus, and FIGURE 2 shows a similar pictorial representation of the second embodiment.

FIGURE 1 of the drawings shows a pipe handling and laying apparatus 1 which, in use, will be suspended by cables from a hydraulic excavator (not shown). Distance X as marked in the drawing will be about 2.5 metres, in practice, and, in use, a first length of piping which is to be handled or moved from one place to another will be held and supported on the holding and support means 2 and 3 of the apparatus 1. A pipe (not shown) may be located on the holding and support means 2,3 by the introduction of said pipe means in the direction of arrow Y over gripping head 4a of extendible and retractable gripping means 4. Thus the gripping head 4a is firstly arranged within the pipe with the hydraulic ram H of the extendible and retractable gripper means extending substantially axially of the pipe.The pipe will then be brought generally into the area A defined by the chain dotted lines in FIGURE 1, beyond the gripper head 4a.

As shown in FIGURE 1 the gripper head 4a is in its fully extended position with its three legs L fully retracted such that they will be well within the diameter of the pipe carried by the apparatus 1 to enable the pipe to be introduced onto the holding and support means 2,3.

In order to lay the pipe in correct alignment in end to end relationship with a second pipe (not shown) the first pipe, when correctly located on the apparatus 1, is lifted and carried into position and the gripper head 4a introduced into the open end of the second pipe. The ram piston P of the hydraulic ram H is then retracted causing the legs L of the gripper head 4 to pivot into extended positions (increasing the diametrical extent of the gripper head) to thereby grip the interior wall of the second pipe by means of the gripper feet F at the ends of the legs L. This fixes the position of the gripper head 4a relative to the second pipe so that any further retraction of the ram piston P necessarily pulls or draws the lower beam 2 of the holding and support means 2,3, and thus the first pipe, generally axially towards the second pipe and into close relationship therewith.The ram piston P can now be extended again in order to move the gripper head 4a axially further into the second pipe thereby retracting the legs L and releasing the grip of the gripper feet F on the inside of the second pipe. In this position the whole apparatus 1 can be withdrawn from the first and second pipe leaving the first pipe laid in correct relationship to the second.

The apparatus 1 is adapted to hold and support pipes of varying length and diameter. In this instance the apparatus can be used to handle and join concrete pipes of diameters from 37.5 cm up to 120 cm and varying lengths from 2.5 metres down to .5 metres. The upper limit on the diameter of pipe which can be handled by the apparatus will be determined by the safe working load and the design of the apparatus may be varied to suit. The holding and support means 2,3 includes two adjustable lower legs 3 so that varying diameter of pipes can be catered for by adjusting the length of these legs 3. The two legs 3 may be made adjustable by any suitable means and could be adjustable together or independently and, for example, they could be telescopic.

The apparatus 1 comprises an upper beam 5 on top of which is mounted a block 6 having adjustable lifting points or eyes 7 to cater for pipes of different lengths carried by the apparatus (in order to balance the load through the centre of gravity). The lower beam 2 is provided with a number (6 as shown) of holes 2a for receiving a stop (not shown) in use, so that a pipe can be located on the locating support means 2,3 with the back upper edge of the pipe resting against said stop located in one of the pair of locating holes 2a (or against the vertical rear stop wall S depending upon the length of the pipe) with three spring loaded safety catches C (only one safety catch shown in FIGURE 1) overlapping the front edge of said pipe. Advantageously, the safety catches C will be located generally equiangularly around the pipe firmly securing the pipe onto the apparatus 1.Each of the two lower, adjustable, legs 3 is attached to an inwardly curved guide rail G which is in firm contact with the inner wall of the pipe.

The pipe will also be seated on an upper guide rail G' resting on the interior of the pipe. This upper guide rail G' runs centrally parallel to the upper portion of the beam 2 in which the holes 2a are located, along an upper one of the legs 3 which is, in this example nonadjustable, and guide rail G' then curves radially inwardly as shown in the FIGURE. Thus the pipe can be securely held and supported on the apparatus in the aforedescribed manner with the safety locking catches C operative. In itself, this method of holding and supporting a pipe for movement by, for example, a hydraulic excavator may be a more reliable and secure method than previous methods more because of the provision of the safety locking catches.

Advantageously, a sealing ring (not shown) can also be held by the apparatus on the front end of the pipe by spring steel strips C' (only one shown in FIGURE 1) on the safety catches C in a manner which it is believed to be self-evident. In this way the pipe with the rubber sealing ring already positioned in front thereof can be introduced successfully to a second pipe and joined thereto with seemingly the minimum amount of fuss. The safety catches C are each provided with pivotable operating arms 0 attached to their associated catches C by operating rods or wires R.

With the pipe in secure location on the lower beam 2 and the sealing ring located in place by the curved spring steel strips C' on the catches C, the apparatus can be lifted by a hydraulic excavator with the upper beam being suspended therefrom at connector point/s 7 on the block 6. The apparatus 1 and pipe and sealing ring can now be swung and lowered into poisition immediately in front of (in end to end relationship) a second pipe already laid in the ground. The pipe and sealing ring can be moved forwards by the excavator until the gripping head 4a (in its extended state with its three legs L retracted) is introduced inside the second pipe. The second, previously laid pipe, will be surrounded by bedding material and, therefore, unable to move so that a firm anchor point can be created when the ram piston 3 is retracted.The gripping head 4a will be inserted into said second pipe until the curved portions of the guide rails G,G' are about to make contact with the second pipe and at this point the ram piston P is retracted.

Retraction of the ram piston releases tension on two steel cables 8 (which cables attach the three legs L of the gripper head to the ram piston P), thereby allowing the legs L to expand outwardly and contact the inner wall of the second pipe. One cable a is attached to the upper leg L and another cable b controls the pair of lower legs in unison. In the example shown, the lower two gripping legs L are of variable length (they may be telescopic) and as should be apparent all three legs L are spring loaded to return to the position as shown in FIGURE 1.

The feet F would usually have a hard rubber outer face to provide a secure grip on the interior walling of the pipe. Further retraction of the ram piston P pulls or draws the front end of the first pipe and the rubber sealing ring towards the open end of the laid pipe, with the gripper head 4a providing a firm anchor point on the second pipe. As the first pipe is drawn generally axially towards the second (said guide rails G,G' helping to maintain good alignment) the outer edge or rim of the second pipe contacts the operating arms 0 thereby pivotting them inwardly and rearwardly to operate rods or wires R to swing the safety catches C inwardly and forwardly (as represented by arrow Z in the FIGURE) to release their hold on the sealing ring just as the edge of the second pipe is about to make contact therewith.

Thus, the first pipe is drawn into the correct relative alignment with the second, laid pipe with the sealing ring sealing the joint therebetween. The two pipes can be firmly drawn together and sealed by the sealing ring in this manner. The ram piston may then be extended again in order to retract the legs L and push the gripper head 4A further into the second pipe. Once the steel cables a,b have moved the legs L into the fully closed up or retracted position the whole apparatus can then be withdrawn from the two pipes with the hydraulic ram H and beam 2 being drawn axially out of the jointed pipe arrangement. The hydraulic ram H may be a two and a half inch cylinder with a three foot stroke (63mm cylinder, 900 mm stroke and the guide rails G,G' may be made from 50 mm round bar).Advantageously the hydraulic ram H may be powered from the hydraulic excavator itself and the controls for the ram may also be located on the excavator and/or on the apparatus 1 itself.

FIGURE 2 shows a second embodiment of the apparatus 1' in which legs 3 are now replaced by larger telescopic inclined legs 3', connected to the rear of beam 2. Legs 3' are connected to the beam 2 at the front end thereof by retaining wires W as shown (only one wire is shown).

Legs 3' are spring loaded downwards against the retaining wires W, which are also of adjustable length. The remainder of the apparatus is in accordance with that already described in relation to FIGURE 2 of the apparatus.

The Applicant has developed a production version of apparatus for laying pipes and this version will now be described by way of example only with reference to the following accompanying drawings in which: FIGURE 3 shows å longitudinal sectional view of the production version; FIGURES 4 and 5 show sectional views taken on lines IV-IV and V-V and drawn on an enlarged scale.

FIGURE 3 shows a production version of pipe handling and laying apparatus 101 which, in use, will be suspended by cables from a hydraulic excavator (not shown). The cables will be connected by eyes (not shown in lifting block L. A section of a first pipe P1 is shown located on holding and support means 102,103 said pipe being introduced onto the holding and support means in the direction of arrow Y over the gripping head 104 of extendible and retractable gripping means 105. The retractable and extendible gripping means 105 includes a hydraulic ram 106 extending parallel to the axis of pipe P1. In this embodiment, a sealing ring 107 is shown on the front end of the pipe P1 and is retained onto said front end by safety catches 108 (only one shown), in a manner which should be generally self-evident.In this way, the pipe P1 with rubber sealing ring 107 already positioned in front thereof can be introduced successfully to the second pipe P2 and joined thereto.

The hydraulic ram 106 is fully extended before introduction of the gripper head 104 into the pipe P2.

When the hydraulic ram 106 is fully extended upper and lower actuating rods llO,llOa are moved outwardly to the left from the position as shown in FIGURE 3 until the nut 111 (threaded onto the righthand end of the upper actuating rod 110a) engages guide block 112 fixed to the top of the cylinder 106a of the hydraulic ram 106.

Further outward movement of the hydraulic ram piston 106b allows connector block 113 to slide along the upper actuating rod llOa against spring biassing provided by spring 114 in a manner which should be generally selfevident, with further movement of the upper actuating rod to the left being prevented by the engagement of the nut 111 with guide block 112. Thus, the upper actuating rod remains stationary as the lower actuating rod 110 moves with the connector block 113 and a head block 115 of the gripper head 104 slides on the upper actuating rod. This relative movement causes links 116 (see also FIGURE 4) to pull on the two opposed legs 117 (to which the links 116 are articulated respectively), thereby causing the legs 117 to close up into a retracted position. The length of the legs 117 is adjustable.

The gripper head 104 is now introduced into the open end of pipe P2 until the guide rails 109 locate into the pipe P2. In FIGURE 3, the retaining wires W of FIGURE 2 have been replaced by spring-loaded leg stays LS which are pivotally connected to inclined legs 118 in the manner shown by way of respective leg clamps 119, adjustment of the length of the lower legs 118 and leg clamps 119 allows the guide rails 109 and safety catches 108 to be brought to bear on the open end of the pipe P2.

It is advantageous that the adjustment operation, once completed for a particular nominal pipe diameter, need not be repeated until another different nominal diameter pipe is to be handled. The pipe-laying apparatus 101 with the pipe P1 is positioned immediately in front of the pipe P2 with the rubber sealing ring 107 being retained in position by way of the safety catches 108 and manoeuvred until the gripper head 104 is inside the pipe P2. The hydaulic ram 106 can now be operated to its retracted position i.e. piston 106b can now be retracted further within the cylinder 106a causing the spring 114 to push on the links 116 and force the adjustable length legs 117 radially outwards to cause gripper pads 120 and 121 (located at the end of the legs 117 and on the head block 115) into contact with the inside wall of the pipe P2. Further retraction of the hydraulic ram 106 increases the grip on the inside wall of the pipe P2 and pulls the pipe P1 axially towards the pipe P2. The guide rails 109 ensure accurate alignment of the pipes P1 and P2 and the safety catches 108 bear on the pipe P2 moving the lower legs 118 up against the spring loaded leg stays LS and the pipe P1 is securely joined to the pipe P2 in sealed manner. The hydraulic ram 106 is then operated to a fully extended position in which the gripper pads 120 and 121 are moved radially inwardly to release the grip on the inside wall of the pipe P2 to allow the pipe handling apparatus 101 to be withdrawn axially from the pipe P1 in a direction to the right as shown in FIGURE 3.

The piston 106b is threadably connected to the connector block 113 and the guide block 112 is welded to the top of the cylinder 106a. A petrol or diesel self-contained power pack and control valves with pressure regulating valve and pressure gauge (not shown) is to be mounted on the main lifting beam M (comprising an upper and lower beam) and it is envisaged that the maximum operating pressure will be about 3,000 p.s.i.

It is to be understood that the scope of the present invention is not to be unduly limited to the particular choice of terminology and that a specific term may be replaced by any equivalent or generic term where sensible. Further it is to be understood that individual features, methods, uses or functions related to the pipe handling apparatus might be individually patentably inventive. The singular may include the plural where sensible and vice versa. Additionally, any range mentioned herein for any variable or parameter shall be taken to include a disclosure of any derivable sub-range within that range or of any particular value of the variable or parameter arranged within, or at an end of, the range or sub-range.

Claims

1. Pipe handling apparatus comprising pipe holding and supporting means to hold and support a first length of piping as it is lifted and introduced towards a second length of piping, and comprising extendible and retractable grip means connected to said pipe holding and supporting means -and adapted in use to grip onto the interior of the second length of piping as the first pipe is moved into the correct alignment therewith.

2. Apparatus as claimed in Claim 1 comprising a single (portable) unit.

3. Apparatus as claimed in Claim 1 or Claim 2 which is adapted for handling pipes of varying length and/or varying size of diameter or cross-section.

4. Apparatus as claimed in any one of the preceding claims which is self-aligning so that as the first pipe is moved or pulled towards the second it is automatically aligned therewith.

5. Apparatus as claimed in any one of the preceding claims in which the grip means is hydraulic or pneumatic in operation.

6. Apparatus as claimed in Claim 5 in which actuation of the grip means moves the pipe lengths together.

7. Apparatus as claimed in any one of the preceding claims in which the grip means is in an extended state while said first pipe is introduced towards said second length and is retracted, to thereby expand the diametrical dimension of a gripper head thereof to grip the interior of the second pipe.

8. Apparatus as claimed in any one of the preceding claims in which the pipe-holding and supporting means of the apparatus comprises a lower support beam (locatable in use within the first length of piping) having an extendible leg or legs which hold onto the interior of the first length of piping during handling of said length.

9. Apparatus as claimed in Claim 8 comprising an upper beam arranged generally parallel with the lower beam.

10. Apparatus as claimed in Claim 9 in which said upper beam includes a block provided with adjustable connection points or eyes for locating cables of lifting apparatus (e.g. a hydraulically operated excavator).

11. Apparatus as claimed in Claim 8, Claim 9 or Claim 10 in which said lower beam houses the extendible and retractable grip means.

12. Apparatus as claimed in any one of the preceding claims in which the extendible and retractable grip means comprises a hydraulic/pneumatic cylinder with ram piston extending generally axially or generally axially parallel to a, or the, lower beam (and first pipe when in use).

13. Apparatus as claimed in Claim 12 in which a, or the, gripper head of the grip means is located on said ram piston.

14. Apparatus as claimed in Claim 13 in which said gripper head is arranged at a distance beyond said lower beam, at least when the grip means is in the extended state.

15. Apparatus as claimed in Claim 14 in which the gripper head is provided with one or more retractable legs which extend (at least radially) to increase the diametrical extent of the gripper head as the grip means is retracted generally axially of said lower beam and first pipe, in use.

16. Apparatus as claimed in Claim 15 in which the gripper head legs are provided with hard rubber feet to grip securely onto the interior walling of the second length of piping to fix the position of the gripper head axially of the second length, so that continued retraction of the grip means causes the first length of piping to be pulled towards the second length.

17. Apparatus as claimed in any one of Claims 12 to 16 in which the legs on the gripper head are adjustable.

18. Apparatus as claimed in any one of Claims 12 to 17 in which the ram piston can be extended to move upper and lower actuating rods in unison until the movement of a first one of said rods is prevented whilst the second rod moves against spring biassing causing retraction of said gripper head legs.

19. Apparatus as claimed in Claim 18 in which said prevention of movement of said first rod is provided by engagement of a nut on one end of said first rod with a guide block fixed to the cylinder, a connector block being provided between the second rod and the ram piston, said connector block receiving the first rod and being movable relative thereto against said spring biassing provided on said first rod, said gripper head legs being attached by pivotable links to said first rod.

20. Apparatus as claimed in Claim 18 or Claim 19 in which said rods are connected to a head block of the gripper head, said gripper head legs being pivotally connected to the head block.

21. Apparatus as claimed in Claim 8 or any claim dependent therefrom having spring loaded leg stays connecting said extendible legs to the lower support beam.

22. A method of laying a first length of piping and joining it to a second length of piping comprising: holding and supporting the first length of piping while it is lifted and introduced towards said second length of piping by pipe handling apparatus including extendible and retractable grip means; introducing said grip means into the second length of piping and actuating said grip means to grip onto the interior of said second length of piping, moving the first length of piping into correct relative alignment with said second length of piping, preferably, by further actuation of said extendible and retractable grip means.

23. A method as claimed in Claim 22 in which said pipe handling apparatus is self-aligning so that as the first pipe is moved or pulled towards the second it is automatically aligned therewith.

24. A method as claimed in Claim 22 or Claim 23 in which the grip means operates hydraulically or pneumatically.

25. A method as claimed in Claim 24 in which the grip means moves the pipe lengths together.

26. A method as claimed in any one of Claims 22 to 25 in which the grip means is in an extended state while said first pipe is introduced towards said second length and is retracted, to thereby expand the diametrical dimension of a gripper head thereof to grip the interior of the second pipe.

27. A method as claimed in any one of Claims 22 to 26 in which the pipe-holding and supporting means of the apparatus comprises a lower support beam (locatable in use within the first length of piping) having an extendible leg or legs which hold onto the interior of the first length of piping during handling of said length.

28. A method as claimed in Claim 27 comprising an upper beam arranged generally parallel with the lower beam.

29. A method as claimed in Claim 28 in which said upper beam includes a block provided with adjustable connection points or eyes for locating cables of lifting apparatus (e.g. a hydraulically operated excavator).

30. A method as claimed in Claim 27, Claim 28 or Claim 29 in which said lower beam houses the extendible and retractable grip means.

31. A method as claimed in any one of Claims 22 to 30 in which the extendible and retractable grip means comprises a hydraulic/pneumatic cylinder with ram piston extending generally axially or generally axially parallel to a, or the, lower beam (and first pipe when in use).

32. A method as claimed in Claim 31 in which a, or the, gripper head of the grip means is located on said ram piston.

33. A method as claimed in Claim 32 in which said gripper head is arranged at a distance beyond said lower beam, at least when the grip means is in the extended state.

34. A method as claimed in Claim 33 in which the gripper head is provided with one or more retractable legs which extend (at least radially) to increase the diametrical extent of the gripper head as the grip means is retracted generally axially of said lower beam and first pipe, in use.

35. A method as claimed in Claim 34 in which the gripper head legs are provided with hard rubber feet to grip securely onto the interior walling of the second length of piping to fix the position of the gripper head axially of the second length, so that continued retraction of the grip means causes the first length of piping to be pulled towards the second length.

36. A method as claimed in any one of Claims 31 to 36 in which the legs on the gripper head are adjustable.

37. A method as claimed in any one of Claims 31 to 35 in which the ram piston can be extended to move upper and lower actuating rods in unison until the movment of a first one of said rods is prevented whilst the second rod moves against spring biassing causing retraction of said gripper head legs.

38. A method as claimed in Claim 37 in which said prevention of movement of said first rod is provided by engagement of a nut on one end of said first rod with a guide block fixed to the cylinder, a connector block being provided between the second rod and the ram piston said connector block receiving the first rod and being movable relative thereto against said spring biassing provided on said first rod, said gripper head legs being attached by pivotable links to said first rod.

39. A method as claimed in Claim 37 or Claim 38 in which said rods are connected to a head block of the gripper head, said gripper head legs being pivotally connected to the head block.

40. A method as claimed in Claim 27 or any claim dependent therefrom having spring loaded leg stays connecting said extendible legs to the lower support beam.

41. Pipe handling apparatus comprising pipe holding and supporting means to hold and support a first length of piping as it is lifted and introduced towards a second length of piping, and comprising:1. retaining means for securely locating a sealing ring relative to one end of said first length of piping as said length of piping is introduced towards a second length of piping, said retaining means acting to hold the sealing ring in place while the first length of piping is joined to said second length of piping, and/or 2. spring loaded safety catches which securely locate the first length of piping on said apparatus during habndling, and/or 3. a portable unit including grip means which is adapted to grip the interior of the second length of piping as the first length of piping is joined to said second length.

42. Pipe handling apparatus substantially as herein described with reference to FIGURE 1, or FIGURE 2 or FIGURES 3 to 5 of the accompanying drawings.

43. A method as claimed in Claim 22 and substantially as herein described.