Embodiments of the present disclosure find applicability in the field of trenchless horizontal directional drilling. One useful field includes systems for placing gas, water, sewer, or other underground pipes, and/or for laying cable underground, including electrical, telephone and fiber optic cable.
Directional drilling machines and methods of use are well-known and well-characterized in the art. Also referred to in the art as boring, thrusting or horizontal drilling, the technology allows for the laying of pipe and cable underground (e.g., gas, water, sewer and drain pipes; ducts; power cables, telecommunication cables, including fiber optic cables, and the like) without needing to excavate or cut open the ground surface along the length of the pipe or cable to be installed. Typically, the process is executed by boring into the ground at an angle to a desired depth, then changing to a horizontal drilling direction. In “pit launched” applications, entry into the ground occurs from a first or “entry” access pit dug into the ground. For drilling distances on the order of 500 ft or less, and pipe or conduits of about 8-inches or less, the drill or boring apparatus can be placed inside the pit, and drilling occurs substantially horizontally from the start. The drill can gain its directional ability by means of an angled steering blade in the drill head behind which typically is a transmitter or locater beacon (e.g., “sonde” or GPS locator) that relays information to an above-ground operator so that drilling height and direction can be manipulated remotely to avoid obstacles and arrive at an intended location.
Directional boring machines are generally configured to drive a series of drill rods joined end-to-end to form a drill string. At the drilling destination, a second access pit or “exit” pit is provided. Alternatively, the destination can be inside or under a building, typically a basement or underground crawl space. When the drill head penetrates the second access/destination pit wall, the drill head is removed in the pit, and a pipe or conduit cable is attached to the drill string, optionally behind a rotating reamer head that serves to enlarge the bore as the pipe or cable is being pulled back through the bore by the retracting drill string. Once the pipe or cable is pulled through the bore hole to the entry access pit, it is disconnected from the drill string, and connected as desired to the service source and service receiver. Patent publications U.S. Pat. Nos. 6,109,831; 5,205,671; 3,554,298; EP 0 904 461; and WO 2013/055389 are representative of the art.
Small model trenchless directional drills (having pullback ratings of 20,0000 pounds or less), currently make up over 60% of the horizontal directional drilling market. Pit launch models, characterized by a hydraulic drive motor that sits in the entry pit to be operated from within the pit, are particularly attractive for operations requiring in the range of about 5,000-20,000 pounds of pullback, drilling lengths in the range of less than about 1,000 ft, and small diameter pipe (typically about 4-inches or less). There is an on-going desire and need for developing small model pit-launched trenchless directional drills that are easy to operate, rugged, and provide the desired pull back capacity and speed without being cumbersome to transport and install.
Current pit launch models typically comprise a chassis or stationary frame that provides means for bracing the device against the front and back end of the entry pit, and a moveable component, typically comprising a hydraulic drive mechanism, that can move or slide the length of the chassis or stationary frame, and is competent to drive a drill stem into the ground from the pit to create a bore hole, and then pull the drill stem back into the pit, typically together with an attached pipe. Generally, the moveable hydraulic drive mechanism also has hydraulic controls for operator manipulation, generally from within the pit. Depending on the size of the pit and the pounds of pullback required, the pit launch device itself may sit within a larger metal box which itself may define the entry pit.
The moveable components of pit launch models in the art generally rely on a glide system of some sort. For example, certain models are designed with the drive motor sliding along a central longitudinal beam that also provides support and stabilization during the drilling operation. Other glide systems have the drive motor suspended between the parallel walls of the chassis frame, and slide along on top of the frame.
There remains an on-going need for compact pit-launched horizontal directional drilling machines that are lightweight, compact, easy to install and set-up, require minimal maintenance, particularly in the field, and which provide maximum life. Current pit launch models can weigh in excess of 1,000 pounds, have dimensions in the range of 5 or 6 ft in length, 4 ft in width, and 3-4 ft in height. This makes the current models cumbersome to transport and maneuver into place, and requires pits to be dug that are of a sufficient size to accommodate them. A smaller, more compact model would mean less digging, less impact to the entry pit site, and less operation time. Moreover, many hydraulic drive mechanisms in the art rely on plastic glide systems or bushings that wear excessively. Others rely on metal bushings that cause excessive friction, reducing the overall effective thrust and pullback power of the device, and/or cause excessive wear on the slide mechanism. Where the slide or rail mechanism is fabricated on top of or over the outside opposing longitudinal side panels of the stationary frame, this adds to the overall weight and size of the device.
There also remains an on-going need for improved means for easily and quickly cracking drill stem joints during operation, both when building a drill string to create a bore hole, and when retrieving a drill string once the bore hole is formed. Accordingly, improvements in stem adapter wrench collars and breakout wrenches and their methods of use are disclosed herein.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter on its own, nor is it intended to be used alone as an aid in determining the scope of the claimed subject matter.
In accordance with one embodiment of the disclosure provided herein is an improved pit launch horizontal directional drilling device. The devices disclosed herein have greater thrust and pullback per unit of power applied, less friction, and less wear or maintenance difficulties, compared with similar pit launch devices in the art.
In one embodiment, the device comprises a chassis or stationary frame component and a carriage component coupled to the chassis and competent to move forward and back along the longitudinal axis or length of the chassis component. The chassis component comprises a back plate, opposing, parallel side panels extending forward from the back plate and ending at a front plate, the front plate comprising a drill bore aperture. The chassis or stationary frame also typically can include a floor plate. Preferably the floor plate includes one or more coverable openings or washout plates for draining any liquid that may accumulate on the chassis floor.
The carriage component, also referred to herein as a drive unit, comprises a hydraulic rotary drive unit for drilling and retrieving an attached drill stem or drill string through the drill bore aperture, a hydraulic directional movement means for moving the carriage component along the chassis between two limiting positions, and hydraulic valving means for directing rotation of an attached drill stem and movement of the carriage component along the chassis.
In another embodiment, the device comprises a linear actuator means for moving the carriage along the frame. In another embodiment, the linear actuator means is a mechanical linear actuator that is hydraulically driven. In still another embodiment, the linear actuator means comprises a toothed rack and gear system. In the art such systems can be referred to as a rack and pinion system or a rail rack system. In still another embodiment, the rack comprises a toothed rack or bar or rod or rail positioned on the inside surfaces of each of the opposing, parallel chassis side panels. In another embodiment, the pinion gear extends or protrudes from lateral opposing sides of the carriage component and is dimensioned to engage the toothed rod or bar positioned on each opposing and corresponding chassis side panel. In one preferred embodiment, a useful gear ratio is 1:6. In another embodiment, other gear ratios can be used to advantage. For example, where more thrusting power may be sought, useful gear ratios can be 1:8 or 1:10 or lower. Those skilled in the art will appreciate that a lower gear ratio can provide more power, and a slower speed.
In still another embodiment, the device has means for reducing friction as the carriage component moves along the chassis. In still another embodiment, the device has means for reducing horizontal vibration as the carriage component moves along the chassis, particularly when the carriage component or drive unit also is drilling a drill stem as it moves along the chassis. In one preferred embodiment the friction reducing means comprises a linear bearing system. In another embodiment, horizontal vibration management means is provided by the linear bearing system. In still another embodiment the linear bearing system comprises a high load capacity bearing guide system. In still another embodiment, the high capacity load bearing system comprises a dual ball bearing and engagement system. In still another embodiment the dual ball bearings comprise an axial load bearing and a radial load bearing. In still another embodiment the dual ball bearings project or extend out from lateral, opposing sides of the carriage component, and the engagement system is located on the inside surface of the opposing, parallel chassis side panels and is dimensioned to receive the bearings. In one currently preferred embodiment, the engagement system comprises a rail. In another embodiment, the engagement system can be a U-channel or I-channel or clamp flange or flange plate, as appropriate.
In another embodiment, a method of drilling a substantially horizontal bore hole from a surface dug pit is provided, using the devices and components described herein.
In still another embodiment devices, components and means are disclosed herein for quickly and easily cracking open drill stem joints during the process of building and retrieving drill stems or drill strings underground. In still another embodiment, an improved drill stem collar wrench, mechanism, and method of use are provided. In one embodiment the collar wrench disclosed herein is integral to the carriage component and can be moved on and off a drill stem adapter easily. In another embodiment a breakout wrench that is integral to the chassis component is provided, along with mechanisms and methods of use.
In one embodiment, provided herein is an integrated, fixed mechanism for movably positioning a wrench collar (or “collar wrench”) over a drill stem joint, the collar having a central channel dimensioned to slide over a rod or tube and having an inner surface dimensioned to inhibit unthreading of a drill stem joint when positioned on the joint. In one preferred embodiment the mechanism comprises attachment means for fixing the collar mechanism to a location on or near the desired drill stem joint; pivotable gripping means for gripping or holding the outer surface of the collar, and a movable handle connected to the pivotable gripping means and competent to initiate pivoting of the gripping means, such that the collar is moved on and off the stem joint by the pivot action.
In one preferred embodiment the mechanism and wrench collar device are fixed to the front end of the hydraulic drive unit. In another embodiment, the gripping means comprises a jaw or C-shaped component with protrusions or pins at its ends, the pins dimensioned to fit into apertures in the collar's outer surface. In another embodiment, the apertures comprise a groove that circumscribes the collar's outer surface. In still another embodiment, the pivotable means comprise pin and eye combinations connecting the collar jaw to the handle. In still another embodiment, a pin and eye combination also links the collar jaw to the fixed attachment means, such that the fixed attachment means acts as a brace support for the mechanism's pivoting action. In still another embodiment, the moveable handle is connected to the pivotable jaw by means of a positioning bar, such that handle manipulation forward and back moves the positioning bar forward and back, causing pivoting of the attached jaw.
In another embodiment, devices, components, mechanisms, systems and methods of use for a drill stem joint breakout system are described. In one embodiment, a drill stem joint breakout mechanism comprises a fixed, positionable wrench element, also referred to herein as a breakout wrench, attached to a surface near a drill stem joint member. In another embodiment, the breakout wrench is attached to a surface so as to be positioned lateral to the joint to be opened. In still another embodiment the surface attachment means comprises a lateral or horizontal slide mechanism, such as a rail mechanism, a tongue and groove mechanism, or an interlocked step or ridge or lip mechanism. In still another embodiment, means for moveably positioning the breakout wrench on and off a stem joint occurs by means of a handle associated with the wrench and competent to move the wrench along the slide mechanism.
The pit launch devices disclosed herein can achieve pull back in the range of at least about 8,000-15,000 pounds, rotational speeds in the range of at least about 100-150 rpm's, accommodate at least about 1100 ft-lbs. torque. They can build and retrieve drill strings extending out at least about in the range of 100-500 ft, and weight less than about 700 lbs. In another embodiment the pit launch devices disclosed herein can weigh less than about 600 lbs. In still another embodiment the pit launch devices disclosed herein can weigh less than about 550 lbs. In still another embodiment, useful pit launch devices disclosed herein can be fabricated to weigh less than about 350 lbs., or even less than about 300 lbs.
In another embodiment, useful pit launch models disclosed herein can be dimensionally compact when compared with similar pit launch deices in the art. Useful devices can have a chassis that is in the range of about 2 ft wide, and side panels with a height in the range of about 6-12 inches. Chassis lengths can be in the range of about 4 ft when using 2 and 3 ft drill pipes, and shorter for shorter drill stems. As described herein below, using an extendable tailstock for the chassis' back plate keeps the chassis dimensions compact, and still adaptable to accommodate larger drill pipes, such as 3-ft pipes. In still another embodiment, devices wherein the carriage component is engaged with the chassis component, the overall height of the device can be in the range of about 20-26 inches.
The foregoing aspects and many of the attendant advantages of this disclosure will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
Embodiments of the present disclosure provide devices, components, mechanisms and methods of use for directional drilling in confined spaces, and more particularly for horizontal directional drilling using a lightweight, portable, pit launch device having enhanced function and durability. Also disclosed are devices, components, mechanisms and methods of use for easily and quickly cracking drill stem joints during drilling and/or cable pulling operations.
The pit launch hydraulic horizontal drilling devices disclosed herein are compact, lightweight and portable. The devices can be dimensioned to accommodate 18-inch, 2-ft or 3-ft drill stem pipes, with thrust and pullback power in the range of at least about 8,000-15,000 lbs, at least about 1100 ft-lbs. torque, and capable of delivering drill stems or strings distances underground in the range of at least about 100-500 ft. Moreover, the devices can be fabricated to weigh less than about 600 lbs, and even less than about 550 lbs. or 500 lbs, as desired. Particularly where shorter drill pipes are being used, the devices can weigh on the order of about 300-400 lbs.
As illustrated in
Front plate 34 also can include an aperture 35 through which a drill string can be bored into the earth in a substantially horizontal manner. Aperture 35 also can include a wiper plate 36 which itself can have an aperture 37. Wiper plate 36 can assist in wiping liquid and/or debris off a drill string, particularly when the drill string is being retrieved during a cable or conduit pulling operation. In addition, floor 31 of chassis component 14 can also include an opening and washout plate or cover 25 for draining any fluid that can accumulate in the chassis during operation.
Chassis component 14 also can comprise a standing plate 12 that can be attached to one or both longitudinal side panels 17 of chassis component 20. Standing plate 12 can provide a surface on which the device operator can stand or otherwise position him or herself during operation, and can include a slip-resistant, durable surface, preferably permeable to liquid. Metal grill work surfaces can be used to advantage. Placing the standing plate for an operator outside the device is another means for enhancing the compact, lightweight character of the device of the present disclosure.
Standing plate 12 can be attached to chassis component 14 by any standard means. In one embodiment, plate 12 can comprise one or more pins 20 that fit into apertures 19 in chassis 14. In another embodiment, pins 20 fit into hollow tubings 33 that span chassis component 14 and are accessible from both side panels via apertures 19, making device 10 universal or symmetrical with respect to standing plate 12. This allows the operator to choose and change on which side to locate the standing plate based on the conditions of the site location as desired. In one preferred embodiment, tubings 33 are fabricated and attached to chassis side panels 17 using metals of appropriate strength and load bearing capacity so as to provide both a means for receiving pins 20 and provide bracing support for device 10 during operation.
Chassis component side panels 17 can each include parallel, opposing gear racks, also known as toothed rods or bars 24 for engaging a hydraulic gear drive mechanism on drive component 18. Sides 17 also can include guide systems 23 for receiving and holding high load capacity linear bearings 30 on drive component 18. In the figures guide system 23 is depicted as a rail. It will be understood that the guide systems, also known in the art as linear bearing system rails, can include rails, !-channels and U-channels. Other rails used to advantage with high load capacity linear bearings can include clamp flanges or clamp plates where appropriate.
As illustrated in
Drive component 18 also preferably includes a hydraulic motor 70 for driving the rotational motion of a drill stem to be added to or removed from a drill string. As illustrated in
One embodiment of a gearing mechanism 72 is illustrated in
As will be appreciated by those having ordinary skill in the art, a gear-based control system provides a means for transmitting rotational motion from an input gear to an output gear, varying the speed ratio by varying the gear ratio. Any useful gear ratio can be fabricated without undue experimentation. One commonly useful gear ratio is in the range of about 2:1, and the mechanism in
Device 10 dimensions can be optimized by optimizing arrangement of hydraulic components of drive mechanism 18. In the figures, (see, e.g.,
In the embodiment illustrated, gear drive mechanisms 84 (see, e.g.,
Linear dual ball bearing systems are well understood and available in the art; useful sources include, without limitation, Pacific Bearing Company and their Hevi-Rail linear guide or glide systems. Choice of bearing and guide system will depend on the dimensions chosen for the device being fabricated, the desired thrust and pullback of the device, and the drilling distances anticipated. Those having ordinary skill in the art will appreciate that useful engagement systems for receiving the high load capacity bearings could include U-channel glides, I-channel glides, and flared plates. In one embodiment, linear bearings useful in the device have a fixed axial bearing. In another embodiment, useful linear bearings having a radial load w/alt. rail have a dynamic load in the range of least about 24 KN, and a static load in the range of at least about 33 KN. In another embodiment, useful linear bearings having an axial load w/alt. rail, have a dynamic load in the range of at least about 10 KN and a static load of at least about 14 KN. Those skilled in the art will appreciate that the high load capacity linear bearing and guide system manages torque generated during the drilling or pulling operation, and reduces friction. In addition, the toothed rack and pinion gearing system limits unwanted slide back during operation, which can be a common operational issue at higher pullback and thrust values, particularly at values greater than about 5,000 foot-lbs.
As described above for the gear-based control system, choice of the toothed rack and pinion gearing also can be varied, depending on the power needs of the operation. One useful gear ratio is 1/6 or 1:6. Others can be used to advantage and can be determined by those having ordinary skill in the art, provided with the instant disclosure. For example, where greater thrust or pull back capability is desired, lower ratios may be selected including, without limitation, 1:8 or 1:10.
Chassis dimensions can be built as desired. Dimensions need to accommodate drill stem, motors and gearing mechanisms. Stacking components allows for narrow, shallow boxes. The device can be placed in, braced against, and/or bolted to the front and back of an entry pit (e.g., using bolt holes 38) as is. Alternatively, it can be placed inside a larger box that provides the pit launch parameters. Choice of materials for chassis and drive unit fabrication are within in the skill of the art to determine, with attention given to selecting materials of suitable strength, load capacity and durability, among other standard criteria.
Referring now to
Referencing
Collar 56 further can comprise an inner circumference contour dimensioned to mirror the outer circumference contour of adapter 92 and the stem flat component of a stem pipe section 58. That is, the inner contour of collar 56 can comprise opposing parallel flats 93 machined along its internal longitudinal axis, the flats 93 having substantially the same dimensional width as stem adapter flats and drill stem flats.
Collar 56 also can comprise an integrated positioning mechanism for moving the collar on and off a stem adapter/drill stem joint. When positioned over the joint, collar 56 and the collar's inner circumference contours hold the joint members stable relative to one another, preventing undesired unthreading when pipe sections are being cracked open using a breakout wrench during pipe string retrieval. While collar 56 also can be used to prevent over-torquing or over-rotation, for example while attaching pipe section 58 to a building drill string or during drilling of the string, drill stem joints having utility in the present disclosure typically use tapered threads designed and fabricated to prevent over-torquing when engaged, and so use of collar 56 may not required during forward drilling operation.
When not in use, it is preferable if collar 56 can be located near the joint, out of position. Wrench collar integrated positioning means 62 provides an example of a useful mechanism for achieving this outcome. The mechanism comprises a claw or jaw or C-shaped component 54 that grips collar 56 and moves it in and out of position. In one embodiment the gripping mechanism comprises pins or protrusions 55 extending out from the ends of jaw 54 and which fit in a groove or track 57 scribed into the outer circumference of collar 56. Jaw 54 is maneuvered by means of attached positioning arm 63 that extends up from jaw 54. Positioning arm 63 can be manipulated by device handle 50 through its positioning bar connector 65. In one preferred embodiment, handle 50 and its positioning bar connector 65 engage with arm 63 by means of positioning bar 52, which can be adjustable, for example by threading means about bar 52's surface that can be screwed into connector 65. In another preferred embodiment, collar wrench positioning mechanism 62 further can be supported by a brace 60 that projects out from or is cantilevered from the anterior end of the directional drive mechanism. Preferably, brace 60 has a pivotable connection to arm 63. In another preferred embodiment, arm 63 has pivoting attachment means for connecting arm 63 to bar 52, and to brace 60. In one embodiment, a useful pivoting attachment means can include an eye and pin combination 61. Of course, other pivot means are within the skill of the art to fabricate and utilize.
In the drawings, when handle 50 is pulled back, attached connector 65 also is pulled back, causing retraction of positioning arm 63 by means of bar 52. As positioning arm 63 is pulled back by arm 52, pivoting means 61 cause the ends of jaw 54 to be pulled forward and wrench collar 56 now is pushed forward on to the stem/adapter joint by means of pins 55 in groove 57. This position can be called the “engaged” position. When handle 50 is pulled forward, arm 63 is pushed forward via bar 52, and pivot means 61 cause attached jaw 54 to move backwards, pulling collar 56 off the stem/adapter joint by means of pins 55 in groove 57. This position can be considered a “resting” position.
With reference to the figures, a breakout wrench device, mechanism and method of use are disclosed herein. In accordance with one embodiment of the present disclosure, during drilling, when the carriage is in a full forward position, a free drill pipe stem has been threaded onto and added to an existing drill string or drill stem 46 and the drill string has been drilled forward into the ground such that the drill adapter/stem joint now is at or near the front plate and front plate aperture 35. This location is sometimes referred to in the art as the “pit face” and defines the forward-most or second limiting position for the carriage. The adapter/stem joint now needs to be cracked or broken open to release the drive unit from the drill string. Once the wrench is positioned on the joint, the rotational hydraulic drive rotates the drill stem to “break open” the joint and unthread the stem from the drive unit. The drive unit now is released from the drill string, the wrench is removed from its joint position, and the carriage can be moved back to it rear-most position in the chassis (also referred to herein as the first limiting position). At this first position, a new stem pipe is threaded onto the adapter, the carriage is moved forwarded, and the pipe rotated to thread its free end onto the exposed and available stem end of the drilled string. Once threaded onto the existing string, the hydraulic drive unit moves the carriage forward again along the chassis longitudinal axis, drilling the newly added pipe into the earth, until the carriage reaches it second limiting position at the pit face again. The adapter/stem joint then is broken open with assistance of the joint wrench, as before, and the process repeats until the desired drill string length as been created.
When a drill string is being retrieved, the joint between pipe stem adapter 92 and drill string first can be cracked open as described above. Collar 56 then is engaged, and carriage 18 is moved back to its full re-set position, bringing with it the pipe string so that the next proximal forward pipe joint is available to the drill stem joint wrench breakout system. Wrench 44 then can be used to crack open this joint so that newly exposed pipe stem can be easily unthreaded from the drill string. Collar wrench 56 then is moved off the stem/adapter joint and the hydraulic rotational means used to unthread the stem from the adapter. The free pipe is removed and the carriage then is moved forward to the pit face. The adapter once again is threaded onto the newly exposed stem joint, the collar wrench positioned onto the new stem/adapter joint, and the carriage pulled back again to retrieve the next stem. The process and steps are repeated until the string is completely retrieved and the drill head or reamer, along with any attached pipe or conduit, have been pulled through the pit face and aperture 35 into the chassis interior.
Embodiments of this disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the disclosure being indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the disclosure.
This application claims the benefit of Provisional Application No. 62/293,786, filed Feb. 11, 2016, the disclosure of which is hereby expressly incorporated in its entirety by reference herein.
Number | Name | Date | Kind |
---|---|---|---|
3554298 | Klein | Jan 1971 | A |
5205671 | Handford | Apr 1993 | A |
6109831 | Handford | Aug 2000 | A |
6206345 | Lenahan | Mar 2001 | B1 |
6736219 | White | May 2004 | B1 |
6860514 | Wentworth | Mar 2005 | B2 |
7318491 | Riel | Jan 2008 | B2 |
20100193247 | Riddle | Aug 2010 | A1 |
20120230771 | Farley | Sep 2012 | A1 |
20130327543 | Reddy | Dec 2013 | A1 |
Number | Date | Country |
---|---|---|
980461 | Aug 2006 | EP |
2013055389 | Aug 2013 | WO |
Entry |
---|
Archive from Mar. 16, 2015: PBC Linear, Hevi-Rail® Combined Roller Bearings-High Load Linear Motion Product Webpage, available at https://web.archive.org/web/20150316205330/http://www.pbclinear.com/Hevi-Rail-Combined-Roller-Bearings--High-Load-Linear-Motion (Year: 2015). |
Involute gear. Wikipedia entry. Available at https://en.wikipedia.org/wiki/Involute_gear (Year: 2020). |
Grundopit 40/60 Mini-Directional Drill—marketing brochure by TT Technologies, Inc.,2020 E New York Street, Aurora, IL 60502, dated 2005. |
On-line Marketing Brochure: McLaughlin McL-10, by Mclaughlin Group, Inc. 2006 Perimeter Road, Greenville, SC 29605 http://www.mclaughlinunderground.com/wp-content/uploads/2013/08/McL-10-Lit.pdf. |
Manual: McLaughlin McL-10 Manual, , by Mclaughlin Group, Inc. 2006 Perimeter Road, Greenville, SC 29605. |
Pow-r Mole—marketing brochure by Pow-r Devices, Inc., 1400 Commerce Pkway, Lancaster NY 14086. |
Article: “Small HDDs Take It the Final Feet”, in Construection Equipment, dated Nov. 1, 2006; url: https://www.constructionequipment.com/small-hdds-take-it-final-feet. |
Screenshot: DitchWItch PT1010 directional drill specifications—web page: https://www.mascus.com/specs/horizontal-drilling-systems-controllable_980141/ditch%20witch/pt-1010_989642. |
Ditch Witch PT1010 images, from web. |
Screenshots from Demonstration You Tube video “Pit Shot Drill” published Nov. 16, 2018. Url: https://www.youtube.com/watch?v=vUyiAM7NFY8. |
MROSupply, Gear Rack Systems on-line description https://www.mrosupply.com/gears-gear-rack/gear-rack/ , retrieved Aug. 13, 2020. |
Atalanta Drive Systems: Gear Racks: https://www.atlantadrives.com/racks.htm?msclkid=942118db8335128a20ca433a817e3dd9 retrieved Aug. 13, 2020. |
Adantex: Gear Rack Catalog. p. 4 of : https://andantex.com/wp-content/uploads/2016/06/andantex-catalog-final-v4.pdf. |
KHK Stock Gears:Online Gear Rack Catalog: https://khkgears2.net/catalog3/ retrieved Aug. 13, 2020. |
Number | Date | Country | |
---|---|---|---|
62293786 | Feb 2016 | US |