Patent Application
20090155040
The present invention relates to pipe handling equipment generally, and in particular relates to a grapple device for tie-ins of large diameter pipes in pipelines typical in the oil & gas industry.
In typical tie-in situations the pipe lays in the ditch with an overlap of pipe at the tie-in point. When the tie-in crew arrives they use side booms to pick up the pipe and align it so that it can be marked and cut to length. When cutting off the excess pipe, a side boom is normally placed at the center of the tie-in to hang onto the piece of pipe being cut off so that it can be removed from the trench. When the excess piece of pipe is cut off, the side boom must try and maneuver in usually very tight quarters and turn 180 degrees to place the excess pipe on the side of the work area and then reposition itself to assist on the tie-in. This causes a great deal of ground disturbance by the side boom turning and it takes extra time because a tie-in crew cannot always have all of its equipment in place until this function has been done due to the space required to turn the side boom around when carrying a piece of pipe.
Once the excess pipe has been cut off, the remaining pipe section is ready to be aligned with an end of a pipe, or pipeline, under construction, and clamps are put on the weld joint to help align the pipe ends to be welded. A typical tie-in crew would achieve the line-up for welding by positioning their side booms in such a manner as to give themselves leverage to pull or lift the pipe section in a side-to-side and upward movement. An industry term for this procedure is “break-over” which means hooking the side boom far enough back from the end of a pipe section that, when lifted, the pipe section will deflect so that it will stay level or at a desired angle for alignment with the pipeline to which it will be welded. To achieve this with the use of side booms is difficult as it sometimes requires moving the side booms to different positions to get proper break over, and having the side booms place their load lines at extreme angles perpendicular to the pipe to attempt to achieve sideways movement for the final fit up so that the weld joint can be welded within industry specifications. This can be very time consuming and can cause the weld joint area to become unsafe due to stress being introduced into the weld joint from the side booms deflecting pipe to achieve a line up for welding. Conventional line-up clamps for tie-in welding are typically only 6 to 8 inches in width and are designed to hold the pipe in place for welding. If the weld joint experiences a lot of stress in achieving the line-up and the line clamps break, then the ends of the pipe have the potential to move rapidly in any direction and can potentially cause serious injury to workers in the tie-in area.
What is therefore desired is a novel pipe grappling apparatus which overcomes the limitations and disadvantages of the existing devices and pipe tie-in methods. Preferably, it should assist in large diameter pipeline tie-ins and in safe retrieval of pipe from hazardous trenches. It should facilitate the handling and alignment of pipe segments for easier and safer welding of the pipe joints. Specifically, it should provide for the gripping and manipulating of one pipe segment to bring it into alignment with another pipe segment, for gripping the other pipe segment, and for positioning, or butting-up, the ends of the pipe segments suitably for welding the resulting joint. The apparatus should have at least two degrees of movement to facilitate clamping of the apparatus onto the pipe segments, and a third degree of movement to bring the pipe segments into abutment. The apparatus should be detachably mountable to a lifting device, such as a backhoe, which itself may provide further degrees of movement to aid in pipe alignment and tie-in.
The grapple apparatus of the present invention, also referred to as a “Tie-in Hand”, is particularly suited to assist in pipe retrieval from hazardous trenches and in large diameter pipeline tie-ins where workers must perform difficult tasks such as aligning weld joints. Such pipelines can convey large volumes of fluids, such as oil, natural gas or other petroleum products. The grappler is designed to handle pipe segments made of various materials, such as metal, plastic or concrete for use in pipelines such as sewers and the like.
Hence, according to the present invention, there is provided in one aspect a grapple apparatus comprising:
a frame having a first frame portion and a second frame portion movably secured to the first frame portion;
a first pair of grapple arms pivotally mounted to the first frame portion about a first axis;
a second pair of grapple arms pivotally mounted to the second frame portion about said first axis;
means for actuating said grapple arms between a first open position and a second closed position for engaging and grasping an object; and,
means for displacing the second frame portion relative to the first frame portion to provide freedom of movement in the direction of the first axis to displace the first pair of grapple arms relative to the second pair of grapple arms.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:
The figures show a grapple apparatus, or “grappler”, according to the present invention (generally designated by reference numeral 20) for grasping and maneuvering one or more suitably shaped objects, such as the illustrated tubular first and second (i.e. left and right) pipe segments 10 and 12, respectively.
Referring specifically to
A first pair of opposed grapple arms 40a, 40b, identified collectively as 40, and sometimes referred to as tongs or a tong assembly, are pivotally mounted below the left frame on a pivot assembly 42 for rotation about a first common axis X2 (running parallel to axis X1). Similarly, a second pair of opposed grapple arms 50a, 50b (50b being hidden from view in
A means for actuating each pair of grapple arms 40, 50 is provided to move each of the arms between a first open position (as shown in
Two additional degrees of movement are provided by a support member 70 attached to the left frame 22 having a means for rotating the frame 20 about the mutually perpendicular axes Y1 and Z1. The support member 70 has two main components. First, a pivot assembly 72 has spaced mounting members 74 suitably configured for detachable mounting to a lifting device (not shown), such as the arm or boom of a mobile material handling machine, for instance a backhoe, and has a lower plate member 78 adapted to pivot about a pin 77 centred on the axis Y1 relative to an upper plate member 76. Second, a swivel assembly 80 is operatively engaged between the lower plate member 78 and the top of the left frame 22 for rotating the entire frame 20 relative to the support member about the axis Z1, driven by a hydraulic “orbital” motor 82. The axis Z1 is oriented generally perpendicularly to the common axis X1, and in turn the axis Y1 is oriented perpedicularly to both the axies X1 and Z1. It will be appreciated that the support 70 may alternately be attached to the right frame 24 to provide substantially the same operation, but this is not preferred in the
It will be understood that the lifting device should provide further degrees of movement. It is expected that the lifting device should be able to lift and lower the grappler along the Z axis, and to provide side-to-side motion along the XY plane (i.e. the plane formed by the X and Y axes). Further, some twisting motion about the X axis may also be possible. This is in addition to the beneficial three degrees of movement provided by the grappler along or about the X1, Y1 and Z1 axes relative to the mounting members 74, and namely the lifting device.
The inner surface 48 of each grappler arm should be made wide enough so that each pair of grappler arms can firmly grip and hold a respective pipe segment during welding of those segments. However, certain applications might require more than one pair of grappler arms to achieve a desired pipe grip, and so it should be appreciated that two or more longitudinally spaced pairs of grappler arms may be provided on one or both of the left and right frames 22, 24 in alternate embodiments.
A pair of outwardly protruding hooks 38 for supporting a pipe safety sling is provided at the left end 26 of the left frame 22 and at the opposed right end of the right frame 24.
The many advantages, operation and method of using the present invention may now be better understood.
The grappler is first operatively connected to a backhoe (or other lifting device) by connecting the mounting members 74 to the backhoe's arm, and by connecting all three of the grappler's hydraulic systems, namely one for each of the internal ram 34, the actuators 60 and the orbital motor 82, to the backhoe's hydraulics for operation therefrom. It is understood that some or all of the grappler hydraulics may be connected to an alternate hydraulic system for remote operation from a location other than the backhoe, but this is not the case for the present example. With the grappler mounted on the backhoe, the backhoe can then position itself at the tie-in point and maneuver the grappler so that both pairs of grapple arms 40, 50, in the open position, are placed over a segment of pipe in a trench (as discussed in the Background) and are then actuated into the closed position to grasp an “excess” portion of the pipe segment to be cut off. Once cut off, the backhoe lifts the grappler which is holding the excess (cut-off) piece of pipe and simply spins around to place the excess pipe out of the way of the trench. This twisting may be advantageously facilitated by the grappler's freedom of movement about the Z1 axis. No moving of other equipment is needed for this task, unlike prior art methods.
Once the excess pipe has been cut off and removed, the remaining pipe (shown as the left pipe segment 10 in
Among other advantages, the grappler should advantageously take the place of at least one side boom on a normal tie-in crew, and in addition increase safety and productivity of tie-in jobs. The grappler should provide a lifting device with the ability to reach into hazardous trenches or ditches, grab pipe sections that are in the ditch, and lift them out, and to further to assist in a tie-in without the need for a worker to go into the ditch to hook onto the pipe. Hence, the grappler is suited to hold a single piece of pipe with one or both sets of grapple arms, or to maneuver two pipe segments simultaneously as shown in
It is noted that the hydraulic system with which the grappler communicates, whether on the lifting device carrying the grappler or other such system, should be equipped with lock out valves or the like so that the grappler's hydraulically operated components do not move during welding operations.
The above description is intended in an illustrative rather than a restrictive sense, and variations to the specific configurations described may be apparent to skilled persons in adapting the present invention to other specific applications. Such variations are intended to form part of the present invention insofar as they are within the spirit and scope of the claims below.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2608453 | Oct 2007 | CA | national |
