GB2319763A - Clamp - Google Patents

Abstract

Apparatus for gripping an object such as a pipe 15 comprises first and second leg members 3, 5 which can be positioned between the object to be picked up and pivoted gripping members 17, at least one of which can be moved towards and way from the other gripping member 17 by a longitudinally movable member 25 of an actuator 21 e.g. piston and cylinder device. Preferably the grips 17 are pivotally mounted in a recess in the leg members 3, 5 and biassed by springs 10 away from the object to be picked up. Preferably extension of the piston causes the end of the grips to pivot out of the recess. Preferably each leg has two jaws and the distance of the legs apart can be adjusted to suit the size of the object to be picked up e.g. by screwed spindle (11, Fig 1d). The device is preferably used as a pipe handler in the off-shore drilling industry.

Description

"Apparatus for Clutching an Object" This invention relates to apparatus for clutching an object, and particularly, but not exclusively, to apparatus for handling pipes and other generally cylindrical objects.

Conventionally, drill pipes for use in offshore oil and gas exploration industry are stacked on the drill floor in relatively close proximity to one another, when not in use. This close stacking presents some difficulties when the drill pipes are required to be moved, as there is a limited space on either side of each drill pipe.

Conventional pipe handling equipment uses a two arm arrangement which is lowered into the gap at either side of the drill pipe requiring to be moved. A plurality of L-shaped fingers are rotationally mounted on each arm, and when each arm is inserted into its respective gap, the L-shaped fingers are arranged to lie flat with respect to the arm. When the pipe is required to be handled, the L-shaped fingers are all rotated by 900 so that the bottom portion of the Lshaped fingers project inward from each arm and hence, when the pipe handling equipment is lifted, the pipe rests upon the L-shaped fingers. However, this equipment has the disadvantage that the mechanism required to rotate the plurality of L-shaped fingers is complex, and accordingly requires intricate machining.

Further, the equipment may have a relatively high failure rate due to the many moving parts caused by the need to rotate the plurality of fingers.

According to the present invention there is provided apparatus for clutching an object, comprising first and second side-by-side clutch members for receiving between them an object to be clutched, at least one of the clutch members being moveable towards and away from the other, and an actuating member for said moveable clutch member, the actuating member having a longitudinal axis, and being moveable in a direction substantially along its longitudinal axis to induce said movement of the clutch member towards and away from the other clutch member.

Preferably, both clutch members are moveable towards and away from each other.

Preferably, the actuating member is coupled to the moveable clutch member.

Preferably, movement of the actuating member in a first direction provides contact between the moveable clutch member and a portion of the apparatus, and typically, movement of the actuating member in an opposite direction breaks contact between the moveable clutch member and the portion of the apparatus.

Preferably, the portion of the apparatus is set at an angle relative to a longitudinal direction of movement of the actuating member.

Preferably, the apparatus further comprises a biassing device to bias the moveable clutch member away from the object to be clutched, and more preferably, movement of the actuating member overcomes the bias. Typically, the biassing device is a spring.

Preferably, the distance between the clutch members is variable.

Typically, the moveable clutch member is pivotably coupled to the apparatus at a pivot point.

Preferably, each of the clutch members is pivotably coupled to the apparatus at a respective pivot point.

Typically, the moveable clutch member is pivotably coupled to the actuating member.

Preferably, each of the clutch members is pivotably coupled to the actuating member.

Preferably, the moveable clutch member contacts the portion of the apparatus at a point spaced from the pivot point. Typically, the pivot point is at one end of the moveable clutch member and the point of contact with the portion of the apparatus is at the other end of the clutch member.

Typically, the apparatus further comprises a pair of body members. Preferably, each body member has at least one clutch member pivotably coupled to a respective actuating member. More preferably, each body member has a pair of clutch members pivotably coupled to a respective actuating member.

Preferably, a longitudinal direction of movement of the actuating member relative to the transverse direction of the object provides for a lateral direction of movement of the moveable clutch member.

Two embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig.la shows a side view of a first embodiment of an apparatus for clutching an object in accordance with the present invention; Fig.lb shows a side view of the apparatus of Fig.la, in cross section; Fig.lc shows an end view of the apparatus of Fig.la; Fig.ld shows an end view of the apparatus of Fig.la, in cross section; Fig.2 shows an end view of the apparatus of Figs.la, ib, lc and ld in cross section, with some components omitted for clarity, being placed over an object; Fig.3 shows the apparatus of Fig.2 in cross section, clutching the object; Fig.4 shows the apparatus of Figs.la, ib, ic and id in perspective, in an exploded view; Fig.5 shows in perspective the spring loading mechanism of the apparatus of Figs.la, ib, ic and id, in an exploded view; Fig.6 shows a cross-sectional side view of a second embodiment of apparatus for clutching an object in accordance with the present invention; and Fig.7 shows a cross-sectional side view of the apparatus of Fig.6.

Figs.la, ib, ic and id show a first embodiment of a pipe handling apparatus 1 in accordance with the present invention. The pipe handler 1 comprises a left hand body member 3 and a right hand body member 5, the spacing between which defines a jaw 7, and when the pipe handler 1 is required to handle a pipe (denoted as 15 in Fig.2) the pipe handler 1 is lowered over the pipe 15 such that the pipe 15 fits into the jaw 7. The width of the jaw 7 can be varied by rotating a handle (denoted as 39 in Fig.4) which is positioned on one of the square ends 9, being part of threaded bar 11. The left half of the screw threaded bar 11 is oppositely threaded with respect to the right half so that rotating the handle 39 in one direction increases the distance between the left hand body member 3 and right hand body member 5, and rotating handle 39 in the other direction decreases the distance between the left and right hand body members 3, 5. The flexing of the left hand body member 3 with respect to the right hand body member 5 is kept to a minimum by three guide rods 13.

Fig.2 shows the pipe handler 1 being lowered over a pipe 15, with some components having been omitted for greater clarity, namely the guide rods 13, the screw threaded bar 13 and a guard 37, and a central connecting piece 43 which will be discussed subsequently. The spacing between the left hand and right hand body members 3, 5 is adjusted so that there is a slight clearance between the left and right hand body members 3, 5 and the pipe 15. Four pawl plates 17, which are used to clutch the pipe 15, are pivotably coupled to the pipe handler 1 at pivots 19, and are spring loaded by a spring 10 so that the pawl plates 17 are biassed away from the pipe 15. This ensures that the pawl plates 17 do not interfere with the pipe 15 when the pipe handler 1 is lowered onto the pipe 15.

Attached to both the left and right hand body members 3, 5 is a ram 21, the piston of which is coupled to the upper end of a clevis rod 25. The pawl plate 17 is coupled at its upper end to the clevis rod 25 by a pin 29.

The pawl plates 17 slot in the left hand and right hand body members 3, 5 in slotted hole 20. The clevis rods 25 lie in grooves 26, and are retained by retainment plates 28.

When the pipe handler 1 is required to clutch the pipe 15 so that the pipe 15 can be moved or lifted, the rams 21 are actuated, which moves the clevis rod 25 downward. The lower portion of the slotted hole 20 in left and right hand body members 3,5 has an angled face 31. When the clevis rod 25 with pawl plate 17 attached moves downward, the lower portion of the pawl plate 17 makes contact with the angled face 31. As the clevis rod 25 continues to move down, the biassing action of the spring 10 acting on the pawl plate 17 is overcome thus moving the pawl plate 17 inward. When the clevis rod 25 has reached its full stroke, the pawl plates 17 clutch the pipe 15, and this mode of operation is shown in Fig.3. Therefore, longitudinal movement in a downward direction of the clevis rods 25, with respect to the transverse direction of the pipe 15, has brought about a lateral direction of movement of the pawl plates 17. In this mode of operation, the pipe 15 can then be lifted, moved or simply clutched.

A notch 24 is formed on the face of the pawl plate 17 facing away from the pipe 15. The notch 24 is formed so that when the ram 21, and thus the clevis rod 25 has reached its full stroke, the notch 24 sits on the angled face 31. Thus, if the rams 21, or clevis rod 25 were to fail, the pipe 15 would continue to be clutched by the pawl plates 17.

The pawl plate 17 may have a material (not shown) attached to its inner face. The material could be a shock absorbing material for use with handling fragile pipes 15, or a gripping material for providing extra clutching power to the pipe handler 1.

Fig.4 shows the pipe handler 1 as having a guard 37 to protect the inner components of the pipe handler 1 and a handle 39 to aid the user of the pipe handler 1 to vary the widths between the left and right hand body members 3, 5.

Fig.4 shows all the components of the pipe handler 1, in an exploded view. Also shown is central connecting piece 43, which keeps the three guide rods 13 and the screw threaded bar 11 rigid, and hence the pipe handler 1 is kept rigid. Fig.5 shows the spring loading mechanism 41 of the pawl plates 17 in more detail.

A second embodiment of a pipe handling apparatus 50 in accordance with the present invention is shown in Fig.6. The main difference between the pipe handler 50 of Fig.6 and the pipe handler 1 is that the pipe handler 50 has two additional guide rods 13, one located at either end of the body members 3, 5, to provide additional rigidity to the pipe handler 50.

Fig.7 also shows that only one end of the screw threaded bar 11 of the pipe handler 50 has a square end 9, to which the handle 39 has access. In most other respects, the second pipe handler 50 is similar to the first pipe handler 1, and is operated in a similar fashion.

The central connecting piece 43 includes a lifting attachment point 44, to permit the pipe handlers 1, 50, and a clutched object if present, to be lifted by a crane (not shown). It will be understood by those skilled in the art, that the pipe handler 1, 50 is not limited to only handling pipes 15. The pipe handler 1, 50 may also be used for clutching other generally cylindrical objects such as trees. The pipe handler 1, 50 could handle other objects also, such as square objects, if the square object had a clearance between itself and the ground.

It is envisaged that the pipe handler 1, 50 will be used in particular, in situations where there is a limited gap between either side of the object it is required to handle, as it is possible to insert the left and right hand body members 3,5 into thin gaps, which may be only 25mm. It is also envisaged that the pipe handler 1, 50 would be used for handling drill pipes of between 3 inch and 20 inch diameter and up to 3 tonnes in weight. The pipe handler 1 of Figs.la, ib, Ic and 1d is 32 inches in length, and the pipe handler 50 of Figs.6 and 7 is slightly longer.

Modifications and improvements may be made to the embodiment without departing from the scope of the invention.

Claims (18)

1. Apparatus for clutching an object, comprising first and second side-by-side clutch members for receiving between them an object to be clutched, at least one of the clutch members being moveable towards and away from the other, and an actuating member for said moveable clutch member, the actuating member having a longitudinal axis, and being moveable in a direction substantially along its longitudinal axis to induce said movement of the clutch member towards and away from the other clutch member.

2. Apparatus according to claim 1, wherein both clutch members are moveable towards and away from each other.

3. Apparatus according to either claim 1 or claim 2, wherein the actuating member is coupled to the moveable clutch member.

4. Apparatus according to any of the preceding claims, wherein movement of the actuating member in a first direction provides contact between the moveable clutch member and a portion of the apparatus.

5. Apparatus according to claim 4, wherein movement of the actuating member in an opposite direction breaks contact between the moveable clutch member and the portion of the apparatus.

6. Apparatus according to any of the preceding claims, wherein the apparatus further comprises a biassing device to bias the moveable clutch member away from the object to be clutched.

7. Apparatus according to claim 6, wherein movement of the actuating member overcomes the bias.

8. Apparatus according to any of the preceding claims, wherein the distance between the clutch members is variable.

9. Apparatus according to any of the preceding claims, wherein the moveable clutch member is pivotably coupled to the apparatus at a pivot point.

10. Apparatus according to any of claims 2 to 9, wherein each of the clutch members is pivotably coupled to the apparatus at a respective pivot point.

11. Apparatus according to any of the preceding claims, wherein the moveable clutch member is pivotably coupled to the actuating member.

12. Apparatus according to any of claims 2 to 11, wherein each of the clutch members is pivotably coupled to the actuating member.

13. Apparatus according to any of claims 9 to 12, wherein the moveable clutch member contacts the portion of the apparatus at a point spaced from the pivot point.

14. Apparatus according to any of claims 9 to 13, wherein the pivot point is at one end of the moveable clutch member and the point of contact with the portion of the apparatus is at the other end of the clutch member.

15. Apparatus according to any of the preceding claims, wherein the apparatus further comprises a pair of body members.

16. Apparatus according to claim 15, wherein each body member has at least one clutch member pivotably coupled to a respective actuating member.

17. Apparatus according to either claim 15 or claim 16, wherein each body member has a pair of clutch members pivotably coupled to a respective actuating member.

18. Apparatus substantially as hereinbefore described, with reference to the accompanying drawings.