This invention relates to tools adapted for grasping and retrieving objects in remote locations. More particularly, this invention relates to such tools which are specially adapted for grasping and retrieving an upper end of a well column pipe which is situated below ground level within a well casing.
Tools which are adapted for grasping and retrieving a well column pipe from the hollow bore of a well's casing are known. An example of such tool is disclosed in U.S. Pat. No. 7,665,785 issued Feb. 23, 2010, to Newton, et al. Such tools are known to include pipe wall clamping members which may apply excessive localized clamping pressure against the pipe's wall during use for retrieval, especially where the well's column pipe is composed of plastic. Such excess clamping pressure is known to crush or break the upper end of a plastic well column pipe during pipe retrieving use, undesirably frustrating a pipe retrieval operation by allowing the column pipe to fall from the retrieval tool into the casing.
The instant inventive well column pipe retrieval tool solves or ameliorates the pipe retrieval problems discussed above by providing a “U” bracket component which configures one of its arms to include a specialized moveable lower pipe clamping segment.
The instant inventive well column pipe retrieval tool is intended to be used to upwardly retrieve a column pipe from a well's casing. Where the well's column pipe has broken or separated below ground level, the column pipe must be upwardly extracted in order to restore the function of the well. The inventive column pipe retrieval tool may be lowered upon a tether or rope for engagement with the broken upper end of the column pipe. Upon engagement of the tool with the column pipe, the column pipe may be upwardly towed by the rope to ground level.
A first structural component of the inventive tool comprises an inverted “U” bracket having an upper web having lateral and oppositely lateral ends. Lateral and oppositely lateral arm components of the “U” bracket are respectively fixedly attached to or formed wholly with the web's lateral and oppositely lateral ends. The web and arm components of the “U” bracket advantageously form, define, and bound a downwardly opening pipe wall receiving throat where pipe clamping may be performed.
At least one of the “U” bracket's arms, for example an oppositely laterally positioned arm, is necessarily segmented into portions or components including an upper relatively fixed segment and a lower relatively moveable segment. The fixed segment of such oppositely lateral arm is preferably fixedly attached to or formed wholly with the oppositely lateral end of the “U” bracket's web, such attachment causing the fixed segment to be immoveable with respect to the “U” bracket's web and the “U” bracket's lateral arm.
At least a first pin and slide slot or channel combination is preferably provided as means for moveably attaching the oppositely lateral arm's lower moveable segment to such arm's upper fixed segment. In a suitable embodiment, the slide slot or channel of such combination presents a downwardly sloping surface. Correspondingly, such combination's pin slidably engages such sloping surface while performing an arm segments interconnecting function. The slope of the slide slot preferably extends at an angle which assures that the interconnected moveable segment normally slides both downwardly and inwardly or toward the “U” bracket's throat. The downward and throatward travel bias imposed by the slide slot upon the oppositely lateral arm's moveable segment assures that the pull of gravity upon such segment normally moves the segment toward a broken upper end of column pipe received with the “U” bracket's throat.
In order to enhance frictional contact between the “U” bracket's moveable segment and such column pipe's wall, a multiplicity of knurles, teeth or protuberances are preferably formed upon the moveable segment. Where, for example, such protuberances take the form of “V” edged teeth, each tooth preferably extends toward and into the “U” bracket's throat, such tooth extensions pointing vertexes of the “V” shaped teeth toward the wall of the column pipe received within the tool's throat. In order to maintain pipe gripping friction at points of contact between such tooth configured protuberances while avoiding any excess clamping pressure at the site of any single tooth, a multiplicity of “V” edged teeth are preferably vertically arrayed along an inner edge of the moveable segment.
In most circumstances, the wall of the upper end of a well's broken column pipe extends substantially vertically, such orientation giving rise to a mechanical need for correspondingly vertically aligning of the tool's array of frictional teeth. In order to maintain the tool's teeth in vertical alignment, a plurality of second pin and slide slot combinations are preferably provided for further attaching and suspending the arm's moveable segment and for holding the moveable segment and its array of teeth at the desired vertical alignment. To achieve such alignment, the first and plurality of second pin and slide slot combinations may themselves be vertically arrayed along upper fixed segment of the “U” bracket's oppositely lateral arm.
A plastic column pipe which is to be captured and grasped by the instant inventive tool may weigh several hundred pounds, potentially overstressing a single horizontally extending pin. The inventive tool's preferred provision of the additional plurality of second pin and slide slot combinations beneficially disperses such weight over several of such combination's pins as a guard against tool breakage.
In order to enhance the mechanical simplicity and balance of the instant invention's fixed and moveable arm segments and plural pin and slide slot components, the fixed arm segment may be advantageously configured as or formed to be a ladder frame. An adoption of a ladder frame configuration allows the pin components of the tool's pin and slide slot combinations to comprise ladder rungs which span between a pair of parallel and vertically extending rails. Where such ladder rung functioning pins are provided, the angled or sloped slots of the pin and slot combinations suitably reside at or are formed as voids extending through the arm's moveable segment. Alternatively, where the angled slots are presented upon the fixed segments' parallel rails, the rung configured pins may be fixedly attached to and extend forwardly and rearwardly from the arm's lower moveable segment.
Both of the arms of the “U” bracket may suitably be configured to include a pin and slide slot combination mounted lower moveable segment and, where dual moveable segments are provided, both of such segments preferably present throatwardly or inwardly extending friction enhancing protuberances. However, for purposes of enhancement of mechanical simplicity and cost economies in fabrication of the tool, the provision of a moveable arm segment is preferably restricted to a single “U” bracket arm. The “U” bracket arm which opposes an arm which is adapted to include a pipe clamping moveable segment may beneficially present a matching or mirroring multiplicity of friction enhancing protuberances regardless of whether such opposing arm itself has a moveable segment.
In use of the instant inventive well column pipe retrieval tool, a water well's column pipe may have a break or separation at an elevation within the well's casing substantially below ground level. In order to retrieve such pipe, an operator may initially tie a sturdy rope to the “U” bracket, such rope securely engaging the bracket's upwardly oriented web. Thereafter, the operator may lower the tool into the hollow bore of the well's casing until the lower end of the “U” bracket contacts the broken upper lip or edge of the column pipe. Upon a slight further lowering of the tool, the wall of the column pipe enters the “U” bracket's downwardly opening throat.
Thereafter, the operator may pull upwardly upon the rope, causing the frictional teeth of the “U” bracket arm's moveable segment to securely grip and bind against the wall of the column pipe. The tool's provision of multiplicities of friction enhancing protuberances assures that the gripped or clamped portion of the column pipe's wall maintains structural integrity, avoiding any undesirable re-breaking of the pipe during clamp assisted pipe lifting. The vertically arrayed multiplicities of clamping teeth avoids excess localized clamping pressure against a plastic pipe wall, protecting against further pipe breakage and failure of the pipe retrieval operation.
Accordingly, objects of the instant invention include the provision of a well column pipe retrieval tool which incorporates structures, as described above, and which arranges those structures in relation to each other in manners described above, for the performance of beneficial functions, as described above.
Other and further objects, benefits, and advantages of the instant invention will become known to those skilled in the art upon review of the Detailed Description which follows, and upon review of the appended drawings.
Referring now to the drawings, and in particular to Drawing
Referring simultaneously to
Referring further simultaneously to
Referring simultaneously to
Where the “U” bracket's lateral arm 4 comprises the depicted three layer plate strata, the oppositely lateral arms 18 and 64 of the back and front plates 12 and 58 advantageously present fixed components of or upper segments of the “U” bracket's oppositely lateral arm 6. Referring further to
At least a first pin and angled slide slot combination is preferably provided for moveably mounting the moveable arm segment 46 at the lower end of the fixed arm segment 18,64, the pin component of such combination suitably comprising a rearwardly extending screw or bolt 74 and an angled slide slot 47 which extends through the segment 46. Such screw or bolt 74 extends rearwardly through eye 25, and further extends rearwardly through angled slot 47, to finally enter and anchor at eye 69.
It may be observed that the oppositely lateral end of slot 47 is raised above or is positioned substantially higher than such slot's lateral end. The height differential between the ends of slot 47 allows the upper wall of such slot to serve as a slide ramp actuator. In operation, the downwardly directed weight of the moveable segment 46 advantageously causes the entire segment 46 to slidably move downwardly and inwardly with respect to the “U” bracket's upper fixed segment 18,64. During such motion, the bolt or screw 74 acts as a slide pin. In a suitable embodiment, slot 47 is angled approximately 45° from horizontal.
In order to hold the moveable segment 46 in substantially parallel alignment with the lateral arm 4 and with the fixed segments 18 and 64 of the oppositely lateral arm 6, a plurality of second pin and slide slot combinations are preferably provided. In such combinations, angled slots 48 suitably receive screw/slide pins 75 which extend rearwardly through eyes 70 to rearwardly anchor within eyes 26.
The instant invention's arrangement of the fixed segment of the oppositely lateral “U” bracket arm to include parallel plate arms 64 and 18 and to comprise screw pins 74 and 75 spanning therebetween, advantageously configures the upper portion of the oppositely lateral arm 6 as a ladder frame. In such framework, the ladder's rails comprise “U” plate arms 18 and 64, and the ladder's rungs comprise screws or slide pins 74 and 75.
Referring to
Thereafter, the operator may lower the tool 1 into the casing's bore 78. The operator preferably has preliminarily gauged or measured the vertical distance between the column pipe's break 84 and the upper opening of the casing 76. Accordingly, the operator knows the length of downward extension of the rope 86 as at which the desired engagement of the tool 1 with the column pipe 80 must occur. In some circumstances, the entire tool 1 may improperly pass downwardly beyond the break 84 and into the annulus surrounding the column pipe 80. However, such improper downward passage may be readily detected by the operator when the downward dispensation of the rope 86 into the well bore 78 exceeds the gauged depth of the break 84. Upon such improper downward passage, the operator may simply raise the tool to attempt a next successive downward extension toward the break 84.
Upon a properly vertically aligned downward extension of the tool 1, the broken upper lip 84 of the column pipe 80 initially enters the throat 20,62 of the “U” bracket via its inverted “V” shaped or flared lower opening 10. While the upper lip of the column pipe 80 progressively passes upwardly along the throat 20,62, any impingement of the column pipe 80 with the moveable segment or plate 46 slidably moves such plate upwardly and oppositely laterally away from the column pipe. Accordingly, during the initial engagement of the tool 1 with the column pipe 80, the pin and slide channel combination interconnections between the “U” bracket's fixed and moveable segments operatively prevent interference by the moveable segment with the tool's engagement with the column pipe 80.
The downward progress of the tool's engagement with the column pipe is suitably stopped at the vertical position indicated in
In order to enhance pipe holding friction at such plate 46 to wall 80 contact, a multiplicity of protuberances are preferably fixedly attached to or are formed wholly with the oppositely lateral arm's moveable segment or plate 46, such protuberances preferably extending laterally from such plate's lateral edge 51. In a preferred embodiment, such protuberances take the form of a multiplicity of “V” or carat shaped teeth or ridges 50. The lateral arm 4 may similarly present a multiplicity of teeth 38 which are preferably formed wholly with and extend oppositely laterally from the oppositely lateral edge 36 of the lateral arm's middle stratum plate 32. Opposing frictional contacts between teeth 50 and 38 and the wall of column pipe 80 tend to forcefully draw the plate 46 along with its teeth 50 laterally against the pipe 80, securely binding against and clamping such pipe. Vertical multiplications of the teeth 50 and 38 prevents excess localized clamping pressure of any single tooth.
Upon achieving such clamping engagement, the column pipe 80 may be towed upwardly out of the casing's bore 78. While the column pipe 80 downwardly suspends from the tool 1 during such upward towing, the weight of such pipe bears against the sloped lower surfaces of the angled slots 47 and 48. During such towing and tool suspension, a lateral vector component of the weight force imposed by the suspended pipe tends to apply a forceful splaying force against the “U” bracket's arms. In order to allow the middle plate 32 to assist in resisting such arm splaying force, a shortened oppositely lateral arm 33 may be advantageously provided, such arm extending downwardly from the oppositely lateral end of the middle plate's web 30. The screw or bolt 73 which extends through aligned eyes 71, 43, and 27 joins such shortened arm 33 with “U” plate arms 64 to assist those arms in their resistance against splaying of the “U” bracket's arms.
In order to disengage the teeth 50 and 38 from the column pipe 80, an upward pulling force may be applied to the moveable segment or plate 46 via the tether 88 which is attached at the eye 56 which is formed at the distal end of the release arm 54.
Sleeve hooking shoulders 52 and 40 are preferably formed at the inner surfaces or edges 51 and 36 of the moveable segment or plate 46 and the lateral arm's middle stratum 32. Where the tool's lateral arm 4 enters the hollow bore 82 of the column pipe 80, as depicted, and where such pipe presents an annular sleeve coupler 90 (shown in dashed lines), shoulder 52 may engage the lower surface of such sleeve 90 as an alternative means for holding and suspending the column pipe 80. Alternatively, where the tool's oppositely lateral arm 6 enters bore 82 (configuration not depicted within views) shoulder 40 may similarly engage such sleeve lower surface.
While the principles of the invention have been made clear in the above illustrative embodiment, those skilled in the art may make modifications to the structure, arrangement, portions and components of the invention without departing from those principles. Accordingly, it is intended that the description and drawings be interpreted as illustrative and not in the limiting sense, and that the invention be given a scope commensurate with the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
1558902 | Ligon | Oct 1925 | A |
3527494 | Furmanb | Sep 1970 | A |
3926468 | Kondo | Dec 1975 | A |
7665785 | Newton | Feb 2010 | B1 |
8801068 | Goudy | Aug 2014 | B2 |