Patent Application
20080238039
The present invention relates in general to articulated hitch mechanisms for mobile equipment, and in particular relates to hitch mechanisms for modular mobile equipment such as modular drilling equipment.
Drilling equipment for boring into subsurface formations is used in a variety of industrial applications. One particular application is in seismic drilling, which is commonly used in exploration for oil and gas. In seismic drilling, an explosive charge is detonated inside a borehole, and the resultant wave patterns generated in the soil structure in the vicinity of the borehole are recorded (or “logged”) using special electronic equipment. The seismic logs are interpreted by specialists to identify subsurface zones where crude oil or natural gas may be present.
It is generally desirable for seismic drills to be self-propelled so that they can easily moved from one borehole site to another without need for separate means of transport. It is also desirable for seismic drills to be adapted for operation on uneven ground surfaces, particularly when used in hilly or mountainous areas. It is further desirable for seismic drills to be comparatively small in physical size so that they will be more easily maneuverable over rough terrain and in forested areas. It is further desirable for seismic drills to be remotely controllable, to eliminate the need for a riding operator who would be exposed to the risk of injury in the event of the drill overturning or other mishaps which are particularly more likely to occur when operating in rough terrain.
Seismic drilling operations are commonly carried out in remote areas that are not accessible by roads, thus preventing the use of large truck-mounted seismic drilling equipment. It is well known, in such situations, to use drilling rigs that can be flown to the drilling site by helicopter (and therefore may be referred to as “heli-transportable” drills). The cost of transporting equipment by helicopter increases with the weight of the equipment and the size or type of helicopter being used. Accordingly, it is desirable to keep the weight of heli-transportable drilling equipment as low as possible in order for heli-transport to be economically feasible.
The ideal seismic rig for use in remote locations and rough terrain would incorporate all of the foregoing features, while still having the ability to drill seismic boreholes efficiently and to considerable depths.
Many of these desirable features can be individually found in the prior art. Examples of heli-transportable drills may be seen in U.S. patents U.S. Pat. No. 3,767,329 (Houck), U.S. Pat. No. 3,981,485 (Eddy), U.S. Pat. No. 4,192,393 (Womack), and U.S. Pat. No. 4,476,940 (Reichert). However, none of these drills are self-propelled. The Houck drill is demountable for heli-transport, but its components weigh as much as 4,000 pounds, necessitating the use of a comparatively large helicopter and entailing correspondingly high helicopter operating costs.
Self-propelled drill rigs are well known, as are rigs that are articulated and/or track-mounted to facilitate travel over rough terrain. For example, U.S. Pat. No. 3,744,574 (Carley) discloses an articulated, self-propelled, wheel-mounted rock drill. U.S. Pat. No. 6,152,244 (Rokbi) discloses an articulated wheel-mounted drill. Examples of prior art track-mounted drills include U.S. Pat. No. 3,289,779 (Feucht) and U.S. Pat. No. 3,478,832 (Hughes). Each of the foregoing prior art drills is comparatively large and heavy, and neither adapted nor readily adaptable for transport by helicopter.
What is needed, therefore, is a self-propelled seismic drill that is adapted for efficient operation over rough or uneven terrain, and that can be transported by smaller helicopters than known heli-transportable drills. The present invention is directed to these needs.
In general terms, the present invention is an articulated, modular, track-mounted, self-propelled, remote-controlled drilling apparatus demountable into separate components to facilitate transport by helicopter. These components include front and rear track carriages, which are connected in tandem by an articulated hitch means that provides for articulation about all three axes. The articulated hitch means also incorporates track carriage steering means. The track carriages are constructed in accordance with known technology, with each carriage having a pair of crawler tracks which provide enhanced traction and maneuverability over rough or uneven surfaces. The front track carnage has a longitudinal axis parallel to and midway between the crawler tracks of the front track carriage. Similarly, rear track carriage has a longitudinal axis parallel to and midway between the crawler tracks of the rear track carriage. The track carriages have, separate hydraulic drive systems of known type, adapted for cooperative operation. The track drive systems and track carriage steering mechanism are remotely controlled, using known remote control technology, thus eliminating the need to provide an operator's seat and operator's drive and steering controls, with corresponding savings in equipment weight.
The rear track carriage is adapted for demountably carrying a drilling module, the main sub-components of which are a rotary drill mechanism, a primary motor, and a hydraulic pump. The primary motor (preferably a 4-cylinder diesel motor) is adapted to provide power to both the rotary drill and the hydraulic pump, which in turn serves the hydraulic drive systems of the track carriers. Means are provided whereby the motor can be selectively switched between drill drive mode and pump drive mode.
The front track carrier is adapted for demountably carrying a drill support module, the sub-components of which may vary depending on the nature of the drilling operations to be conducted. Seismic drilling is commonly carried out using either water or compressed air. When boreholes are being drilled in cohesive soils such as clay and shale, water is introduced into the borehole (typically via the drill stem) to lubricate the drill bit and to assist in removal of drill cuttings. However, this is less effective (or not effective at all) when drilling in non-cohesive soils such as gravel, in which case it may be necessary or desirable to inject compressed air (via the drill stem) to blow cuttings out of the borehole via the annulus between the drill stem and the borehole. Compressed air is also commonly used when drilling through rock formations or large boulders, which typically entails the use of air hammers to break up the rock.
Accordingly, the drill support module in one embodiment of the invention will primarily comprise a water storage tank, which preferably will have a storage capacity in the range of 200 Imperial gallons. In an alternative embodiment, the drill support module will comprise an air compressor with a dedicated power unit (preferably a small diesel motor). The drill support module in this embodiment may also have a small water tank to provide for situations where drilling will be primarily air-assisted but may require the use of water to drill through localized zones of cohesive material. Flexible water hoses or air hoses are provided, as appropriate, to convey water or compressed air to the drill.
The use of multiple demountable modules, as described above, makes it possible to reduce the weight of individual components of the apparatus to approximately 1,850 pounds or less, thus allowing the use of helicopters than are considerably smaller and more economical to operate than those typically required for known heli-transportable drills. As well, the use of a pair of track carnages reduces the necessary physical size of each carriage, thus enhancing maneuverability. The combination of self-propelled, track-mounted modules with tri-axial articulation and remote controllability enables the assembled apparatus to traverse rough and steep terrain more easily and with greater stability than known self-propelled seismic drill units such as the four-wheel-drive quad units and six-wheeled or eight-wheeled “argos” commonly used in seismic operations. The drilling apparatus of the present invention thus can readily move on its own power between borehole locations, considerably reducing or eliminating the need for separate means (such as a helicopter) for transporting the apparatus between borehole locations.
Accordingly, in a first aspect the present invention is a modular, self-propelled, articulated drilling apparatus comprising:
In a second aspect, the invention is a tri-axially articulated hitch mechanism for demountably coupling a first mobile equipment unit to a second mobile equipment unit, said hitch mechanism comprising:
Embodiments of the invention will now be described with reference to the accompanying figures, in which numerical references denote like parts, and in which:
Referring to
Drilling module 90 includes a structural frame 92 adapted to support a rotary drill apparatus 94, and to carry ancillary equipment (conceptually represented by block 96 in
The primary motor is adapted to selectively drive the drill apparatus 94 or the hydraulic pump, which in turn is operatively engageable with the hydraulic drive systems of the front track carriage 20 and the rear track carriage 30. The primary motor may be of any suitable type (for example, a 4-cylinder diesel motor). Ancillary equipment 96 includes motor control means (not shown) whereby the output of the primary motor can be selectively directed to driving drill apparatus 94 when a borehole is being drilled, or to driving the hydraulic pump so as to power the hydraulic drive systems of track carriages 20 and 30 when the apparatus 10 is in transit between borehole locations. Persons skilled in the art of the invention will readily appreciate that various types or configurations of motor control means suitable for this purpose may be devised in accordance with technology well known in the field. Preferably, the motor control means is electronically controlled.
Drill support module 80 includes a structural frame 82 adapted to carry ancillary equipment (conceptually represented by block 84 in
The ancillary equipment 84 earned by drill support module 80 may vary depending on the nature of the drilling operations involved, and the subsurface soil conditions at the drilling site. In one embodiment of drill support module 80, ancillary equipment 84 includes a water storage tank, which preferably will have a storage capacity in the range of 200 Imperial gallons. This configuration of drill support module 80 may be desirable when drilling through cohesive soils, as previously described. Flexible water hoses (not shown) are also provided, to convey water from the storage tank to drill apparatus 94.
In an alternative embodiment, ancillary equipment 84 of drill support module 80 includes an air compressor with a dedicated power unit (for example, a small diesel motor). This alternative configuration of drill support module 80 may be desirable when drilling through non-cohesive soils, such as gravel, or when drilling through rock formations or large boulders. Flexible air hoses (not shown) are provided for delivering compressed air from the compressor to drill apparatus 94. The drill support module 80 in this alternative embodiment may also have a small water tank (conceptually indicated in
Hitch mechanism 40 couples front track carnage 20 and rear track carriage 30 such that they can articulate relative to each other about three axes. This articulation capability can be best understood from
Hitch sections 42 and 44 are swivellably connected about a swivel axis XS in the vicinity of their respective inner ends 42A and 44A, using a swivel pin 46 of any suitable type. Hitch mechanism 40 includes steering means, for controlling articulation about swivel axis XS and thus effectively controlling the direction of travel of the drilling apparatus 10 when in transit under its own power. In the preferred embodiment of the invention, the steering means comprises a pair of hydraulic cylinders 48 disposed one on either side of swivel axis XS, each cylinder 48 being rotatably connected at one end to hitch section 42 near its outer end 42B and at the other end to hitch section 44 near its outer end 44B, all as illustrated in
Hydraulic cylinders 48 are operably connected in well-known fashion to the hydraulic pump of drilling module 90 (or, in alternative embodiments, to a dedicated steering pump) by means of suitable flexible hydraulic fluid conduits (not shown). Hydraulic cylinders 48 preferably will be double-acting cylinders, but single-acting cylinders may be used in alternative embodiments.
In the preferred embodiment of the invention, the operation of the primary motor and hydraulic pump of drilling apparatus 10 are remotely and electronically controlled with respect to both track-drive functions and steering functions. The remote control function may be provided using a remote control station linked to drilling apparatus 10 by means of a control cable or by a wireless communication link, in accordance with methods and technology well known to persons skilled in the field of the invention.
Hitch mechanism 40 also includes first axle-mounting means 70A which is mounted to first hitch section 42 at the outer end 42B thereof, generally as shown in
As illustrated in
Second hitch section 44 includes a pivot pin housing 50 disposed between the upper and lower plates 44U and 44L of second hitch section 44. Pivot pin housing 50 has a cylindrical pivot pin bore 51 for receiving a pivot pin. As shown in
Hitch mechanism 40 also includes a second axle-mounting means 70B for receiving a second axle means 72B mounted to second track carriage 30 such that second track carriage 30 is hingeingly rotatable about a hinge axis XH-B transverse to the longitudinal axis of second track carriage 30. The details of second axle-mounting means 70B and its connection to second track carriage 30 are generally as described previously with respect to first axle means 72A, with the exception that second axle-mounting means 70B is mounted to second hitch section 44 so as to be pivotable about pivot axis XP. This feature is provided in the preferred embodiment by means of a split pivot block 60 comprising a first pivot block section 62 and a second pivot block section 64, which are illustrated in
Second pivot block section 64 is matingly engageable with first pivot block section 62 such that semi-cylindrical cavities 62A and 64A combine to form a cylindrical pivot block passage 65. First pivot block section 62 and second pivot block section 64 are provided with means for releasably securing second pivot block section 64 to first pivot block section 62. In the embodiment illustrated in
First pivot block section 62 is securely connected to second axle-mounting means 70B (such as by welding), with the axis of pivot block passage 65 oriented substantially perpendicular to hinge axis XH-B. Second axle-mounting means 70B may now be pivotably mounted to second hitch section 44 using a pivot pin 67 disposed within both pivot pin bore 51 of pivot pin housing 50 and pivot block passage 65 of assembled pivot block 60, so as to be rotatable about pivot axis XP while at the same time being retained longitudinally within pivot pin housing 50 and the assembled pivot block 60.
In the illustrated preferred embodiment of the invention, the diameters of pivot pin bore 51 and pivot block passage 65 are equal, and pivot pin 67 comprises a round shaft 69 having a diameter slightly smaller than that of pivot pin bore 51 and pivot block passage 65, such that pivot pin 67 will be freely rotatable within pivot pin bore 51 and pivot block passage 65. Round shaft 69 has an inner end 69A and an outer end 69B, and has a stop member 67A (such as an annular ring as in
As best seen in
Although pivot pin 67 has been described and illustrated in the simple form of a round bar of uniform diameter with an annular groove for retention within pivot block 60, persons skilled will recognize that pivot pin 67 may take other forms and configurations while still having the functional features described herein. For example, pivot pin 67 could have sections of different diameters, with pivot pin bore 51 and pivot block passage 65 having correspondingly different diameters. Longitudinal retention of pivot pin 67 within pivot pin housing 50 and pivot block 60 may be provided by other means as well. For example, semi-cylindrical cavities 62A and 64A could be formed with annular ridges that are matingly engageable with annular groove 69C of pivot pin 67. In an analogous alternative embodiment, pivot pin 67 could be formed with an annular ridge matingly engageable with annular grooves formed into semi-cylindrical cavities 62A and 64A. These exemplary alternative embodiments would eliminate the need for fasteners 68 to serve as longitudinal retention means, thus providing additional options with respect to the releasable connection of first pivot block section 62, to second pivot block section 64.
In the preferred embodiment, hitch mechanism 40 is provided with limiting means (not shown) for limiting the range of swivelling, pivoting, and hingeing movement about the swivel, pivot, and hinge axes respectively. The limiting means may be provided in the form of stop members, straps, cables, or suitable appurtenances of other types which may be readily devised by persons skilled in the field of the invention.
It will be readily appreciated by those skilled in the art that various modifications of the present invention may be devised without departing from the essential concept of the invention, and all such modifications are intended to be included in the scope of the claims appended hereto. By way of example (and without intending to limit the foregoing statement), first axle-mounting means 70A could be pivotably mounted to first hitch section 42 in addition to or instead of second axle-mounting means 70B being pivotably mounted to second hitch section 44. In another exemplary variant of the invention, the pivot pin may be non-rotatably connected to first hitch section 42 or second hitch section 44, such that it only rotates within pivot block passage 65.
In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following that word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one such element.
This application is a divisional of application Ser. No. 11/149,339, and the disclosure of said application Ser. No. 11/149,339 is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11149339 | Jun 2005 | US |
| Child | 12116849 | US |
