Tool driving or impacting – With vehicle support for drive – Drive structure moved to nonuse position for transport
Reexamination Certificate
2000-10-06
2001-07-10
Smith, Scott A. (Department: 3721)
Tool driving or impacting
With vehicle support for drive
Drive structure moved to nonuse position for transport
C173S147000, C173S184000, C175S085000, C175S122000
Reexamination Certificate
active
06257349
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is generally directed to drilling rigs used for creating wells or blast holes and more particularly to a top head drive and mast assembly which is adapted to be mounted to a conventional mast or derrick of a drill rig such that the drill rig can operate with a rotary top head drive. In a preferred embodiment, the invention will be described as being mounted to a conventional cable drilling rig wherein the top head rotary drive may be easily moved into position for rotary drilling and stabilized in position for advancing a drill string. The top head rotary drive and mast assembly can easily be raised and moved into close proximity with an existing mast or derrick, such as a derrick of cable drill rig, such that the top head rotary drive and mast are out of alignment with a drill hole thus allowing conventional drilling equipment to be fully operational.
2. Brief Discussion of the Related Art
In the boring or drilling of wells or blast holes and the placing of well casing or lining, generally two types of drilling rigs are used. A first rig, known as a cable drill rig, operates using a bit and drill stem which is raised and lowered for impact by a cable system.
As opposed to the reciprocal driving movement created by a cable rig, other rigs, known as rotary air rigs, provide rotation and compressed air through a drill string for drilling. Generally, such rotary air rigs are more efficient in generating greater drilling speeds for drilling wells in a more expeditious manner.
Conventional rotary air rigs incorporate a drill table mounted along a base of a mast. The rotary table includes a drive motor. In order to drill utilizing a rotary table, a kelly system is required wherein a kelly rod is connected to each section of drill pipe as the drill string is lowered. Because of the requirement for the drive kelly to engage within a chuck of the rotary drive head, a significant amount of time and labor is required when adding or removing a pipe section to a drill string as the kelly must be removed from the uppermost drill pipe section during each step.
To overcome the deficiencies of rotary table drive systems, newer top head rotary drive systems have been developed. Top head drive systems include a rotary drive head driven by one or more motors. The rotary drive heads are guided in a vertically reciprocating motion along rails of masts of such systems. Various types of assemblies may be utilized to raise and lower the top head rotary units during use. The benefit of the direct or top head rotary drive system is that the kelly bar required for drive tables is not necessary and the top head rotary drives may be connected directly, or through a coupling member, to an uppermost pipe section of a drill string.
It is preferred that the top head air rotary drive be used when retrieving and or replacing sections of a drill string for purposes of replacing a drill bit, such as in a sequence of tripping out sections of a drill string to replace a drill bit and tripping in pipe sections to reform the drill string.
In view of the foregoing, there remains a need to adapt vehicles having derricks, including conventional cable drilling rigs, such that they may operate with top head rotary drives which may be easily moved into a drilling position to facilitate the expeditious drilling of a bore or well hole and yet can be easily moved out of alignment position with the hole to permit the use of other equipment such as conventional cable equipment.
Some examples of prior art top head rotary drive drill systems are disclosed in the U.S. Pat. No. 3,994,350 to Smith et al., U.S. Pat. No. 4,421,179 to Boyadjieff, U.S. Pat. No. 4,589,503 to Johnson et al., U.S. Pat. No. 4,800,968 to Shaw et al., U.S. Pat. No. 5,038,871 to Dinsdale, U.S. Pat. No. 5,107,941 to Berry, U.S. Pat. No. 5,501,286 to Berry, and U.S. Pat. No. 5,794,723 to Caneer, Jr. et al.
SUMMARY OF THE INVENTION
A top head rotary drive and mast assembly for use with a vehicle or equipment having an elevatable mast or derrick such as a conventional cable drilling rig wherein the assembly includes a rotary air drive head which is mounted to a holding plate which is movable along a mast by being drivingly connected to a control device for raising and lowering the holding plate relative to the mast. In a preferred embodiment, the control device is a hydraulic piston which includes a rod having a rotary device, such as double pulley, mounted thereto about which extend cables or similar elements, one of which extends over an upper pulley at the crown of the mast downwardly to a point of connection with the holding plate and another which extends beneath a lower rotary device or pulley mounted on the mast such that a remote end connects to a portion of the holding plate. Ends of the elements which are remote from the holding plate are anchored relative to the mast such that, as the piston associated with the hydraulic cylinder is moved in or out, the elements are correspondingly played in or played out to maintain constant tension on the holding plate to thereby ensure that the holding plate is stabilized with respect to the mast.
The rotary air drive head and mast assembly further includes at least one, and preferably two, support arms which extend outwardly from an upper portion thereof and which arms have free ends which are adapted to be pivotally connected to support the mast from a derrick of a conventional truck or crawler. To stabilize the mast when mounted to the derrick of such conventional equipment, the assembly further includes at least one, and preferably two, upwardly inclined stabilizer arms which are connected to a lower portion of the mast and extend upwardly at an angle of between approximately 30° to 45° to outer ends which are adapted to be secured to the frame of the conventional vehicle. In a preferred embodiment, a further stabilizer arm is provided which is connected at one end to the lower portion of the mast in vertically spaced relationship with respect to the inclined stabilizer arms and which includes an outer or free end which is adapted to be connected to the frame of the conventional vehicle, such as a conventional cable drill rig. This additional stabilizer arm is inclined at an angle which varies from the angle of inclination of the inclined stabilizer arms and preferably, the additional stabilizer arm is oriented generally perpendicular with respect to a point of attachment on the mast and frame of the rig.
In one preferred embodiment, the top head air rotary drive and mast assembly includes at least one, and preferably two, restraint elements which are adapted to be connected at opposite sides of the holding plate and extend vertically upwardly therefrom to points of connection on the derrick of the conventional cable or other rig. In some embodiments, the restraint elements are cables having looped lower ends which are adapted to be mounted over hooks provided on the holding plate. The restraint elements create a re-direction of force from the control device which normally moves the holding plate in reciprocating motion along the mast. When the restraint elements are in place, should the control device be activated to move the holding plate toward the lower portion of the mast, the restraint elements will prevent such movement thereby causing the connections between the control device and the holding plate to supply a lifting force on the mast when the mast has been connected by the upper support arms to the derrick of the conventional drill rig and the stabilizing arms disconnected from the derrick of the conventional rig. As the mast elevates, it will pivot about the upper support arms and will be drawn into close proximity abutting the derrick. The mast is thereafter retained in the raised position by the control device. In the preferred embodiment, the control device is a hydraulic cylinder such that hydraulic pressure is utilized to retain the mast in an elevated position.
In another embodiment, the lowering and raising of the top head air
Dowell & Dowell , P.C.
Smith Scott A.
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