Field of the Invention

The present invention relates to a rod handling system for a drill rig.

Background of the Invention

During ground drilling, in order to advance a corresponding drill string into the ground or pull the string from the ground, it is necessary to add or remove drill rods from the drill string. This in turn requires individual drill rods to be picked up and carried between a drill rod bin or other storage facility and the drill rig. Usually the rod bin or storage facility is located near the tower with the rods laid horizontally. For example for mobile drill rigs, a vehicle on which the drill rig is mounted may be provided with a rod bin or rod storage area in which the drill rods lay. A jib mounted on the drill tower and a hoist plug or clamshell attached to a wireline of the jib is coupled to a drill rod to enable lifting of the drill rod between the tower and rod bin.

Summary of the Invention

One aspect of the invention provides a rod handling system for a drill rig having a drill tower and a rod bin, the system comprising: a transfer mechanism capable of moving a drill rod between the drill tower and the rod bin while maintaining a substantially constant inclination of the rod.

The system may comprise a rod gripping mechanism that is controllable to selectively grip and release a drill rod, the rod gripping mechanism being coupled to the transfer mechanism wherein the transfer mechanism is operable to move the rod gripping mechanism to effect moving of a drill rod between the drill tower and the rod bin.

A second aspect of the present invention provides a rod handling system for a drill rig having an associated drill tower and rod bin, the system comprising; a rod gripping mechanism that is controllable to selectively grip and release a rod; and, a transfer mechanism operable to move the rod gripping mechanism between the drill tower and the rod bin while maintaining a substantially constant inclination of a rod gripped by the rod gripping mechanism.

The rod gripping mechanism may be arranged to grip a rod at two spaced apart locations along the rod.

The rod gripping mechanism may comprise a spring mechanism to apply a gripping force enabling the rod gripping mechanism to grip a rod, and a release mechanism operable to release the gripping force applies by the spring mechanism.

The release mechanism may be operable to compress the spring mechanism to release the gripping force.

The release mechanism may comprise a ram or a jack.

The ram or jack may be actuated hydraulically, pneumatically or electrically.

The rod gripping mechanism may comprise a plurality of jaws and a wedge, and wherein the spring mechanism biases the wedge between the jaws to cause the jaws to close about and apply the gripping force to a rod located therebetween.

The rod gripping mechanism comprises two spaced apart grippers each gripper being controllable to selectively grip and release a rod.

Moreover the rod gripping mechanism may comprise two spaced apart grippers, each gripper comprising a plurality of jaws and a wedge, the wedge being biased by said spring mechanism to bear against the jaws to cause the jaws to close about and grip a rod, and wherein the release mechanism is configured to release the bias of the spring mechanism to the wedge enabling the jaws to open and release the rod.

The transfer mechanism may be movable between an operational position where the transfer mechanism extends across the drill tower and rod bin and a second position where the transfer mechanism is spaced from the rod bin enabling the rods to be loaded into or removed from the bin.

The transfer mechanism may comprise a frame supported on the drill rig in the manner enabling the frame to be swung between the operational position and the second position.

The transfer mechanism may comprise an actuator operable to swing the frame between the operational and second positions.

The transfer mechanism may comprise a carriage on which the rod gripping mechanism is mounted, and a drive for moving the carriage between the drill tower and rod bin.

The carriage may be slideably mounted to the frame.

The transfer mechanism may be further operable to move the rod gripping mechanism along a path in a direction perpendicular to a direction of movement of the rod gripping mechanism between the tower and the bin.

The rod gripping mechanism may be moveable relative to the carriage to enable movement of the rod gripping mechanism along the path.

The transfer mechanism may comprise an actuator coupling the rod gripping mechanism to the carriage, the actuator operable to move the rod gripping mechanism along the path.

The transfer mechanism may be coupled to the drill rig at a location wherein, when the rod handling system is transferring a rod between the drill tower and rod bin, the transfer mechanism is elevated above a person working on the ground.

A third aspect of the invention provides a drill rig comprising: a drill tower and a rotation head supported on the drill tower; a rod bin capable of holding a supply of drill rods; and, a rod handling system capable of transferring a drill rod between the drill tower and the rod bin while maintaining a substantially constant inclination of the drill rod. The drill tower and rod bin may be held parallel to each other when the rod handling system is transferring a drill rod.

A fourth aspect of the invention provides a method of handling a drill rod in a drill rig having a drill tower and a rod bin, the method comprising: gripping a rod located in one of the tower and the bin; moving the gripped rod to the to the other of the tower and the bin while maintaining a substantially constant inclination of the rod; and, releasing the grip rod.

Gripping a rod may comprise gripping a rod in two spaced apart locations along the rod.

Gripping a rod may comprise utilising a spring to apply a gripping force to the rod and wherein releasing a gripped rod comprises compressing a spring to release the gripping force.

Brief Description of the Drawings

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a representation of an embodiment of the rod handling system fitted to a drill rig;

Figure 2 is an enlarged view from an alternate angle of the rod handling system shown in Figure 1 ;

Figure 3a is a front view of a rod gripping mechanism incorporated in the rod handling system; Figure 3b is a schematic isometric view of the rod gripping mechanism shown in Figure 3a;

Figure 3c is a side view of the rod gripping mechanism shown in Figure 3a;

Figure 3d is a top view of the rod gripping mechanism shown in Figure 3a;

Figure 4a is a side view of a transfer mechanism incorporated in the rod handling system showing the rod gripping mechanism in a sotrage position;

Figure 4b is a plan view of the transfer mechanism shown in Figure 4a;

Figure 4c is one end view of the transfer mechanism shown in Figure 4a; Figure 4d is an opposite end view of the transfer mechanism shown in Figure

4a;

Figure 5a is a partial view of a gripper incorporated in the rod gripping mechanism; Figure 5b is a schematic isometric view of a portion of a gripper incorporated in the rod gripping mechanism;

Figure 6a is an isometric view of the rod gripping mechanism coupled to a trolley incorporated in the transfer mechanism;

Figure 6b is a front view of the rod gripping mechanism and trolley shown in Figure 6a;

Figure 6c is a side view of the rod gripping mechanism and trolley shown in

Figure 6a;

Figure 7a is a schematic isometric view of a cylinder mounting clamp incorporated in the rod handling system; Figure 7b is a plan view of the cylinder mounting clamp shown in Figure 7a;

Figure 7c is a side view of the cylinder mounting clamp shown in Figure 7a;

Figure 8 is an isometric view of the trolley incorporated in the transfer mechanism;

Figure 9a is a schematic isometric view of a jaw housing incorporated in rod gripping mechanism;

Figure 9b is a plan view of the jaw housing shown in Figure 9a; and,

Figure 10 is an isometric view of a frame incorporated in the transfer mechanism.

Detailed Description of Preferred Embodiment

Figures 1 and 2 depict a drill rig 10 to which a embodiment of the rod handling system 12 is fitted. Drill rig 10 comprises a drill tower 14 and a rod bin 16. Drill tower 14 and rod bin 16 are both pivotally supported on and carried by a vehicle 18. Respective hydraulic rams (not shown) are operable to pivot the drill tower 14 and rod bin 16 independently of each other between horizontal and vertical positions. However when the rod handling system 12 is in use the drill tower 14 and rod bin 16 are held parallel to each other, i.e. at the same inclination.

Rods 20 are disposed in bin 16 as well as in tower 14. Bin 16 holds a supply of rods 20 to be added to the drill string rotated by a drill head (not shown) which travels up and down the drill tower 14. In this embodiment drill tower 14 includes a carousel 22 which also holds a small number of drill rods that are sequentially added to the drill string. As the carousel 22 is emptied by drill rods being progressively screwed into the drill string, the carousel 22 can be replenished with rods from the rod bin 16 by the system 12. Conversely in the event of a rod pull, rods unscrewed from the drill string can be transferred to bin 16 by rod handling system 12.

In broad terms, the rod handling system 12 comprises a rod gripping mechanism 26 (see Figures 1-3b) which is controllable to selectively grip and release a rod 20, and a transfer mechanism 28 (see Figures 1 , 2 and 4a - 4d) which is operable to move the rod gripping mechanism 26 between the drill tower 14 and the rod bin 16 while maintaining a substantially constant inclination of a rod 20 held by the rod gripping mechanism 26. Thus, the rod gripping mechanism 26 can be moved to a position in front of bin 16 by transfer mechanism 28, and subsequently operated to grip a rod 20 in bin 16. The transfer mechanism 28 may then be operated to transfer (or "tram") the rod 20 laterally, while maintaining its inclination, to a position in front of the tower 14. The rod gripping mechanism 26 is then operated to dispose the rod 20 at a location that is aligned with a drill thread under the rotation head. The thread is screwed into the rod 20 and once the thread is made up, rod gripping mechanism 26 is operated to release the rod 20 and moved laterally by the transfer mechanism 28 to be, for example, located in front of bin 16 and out of the way of the tower 14.

The rod gripping mechanism 26 is operated by action of both a spring mechanism in the form of a compression spring 30, and a release mechanism in the form of a hydraulic ram 32. Spring 30 is configured to apply a gripping force enabling the rod gripping mechanism 26 to grip a rod 20. In contrast, ram 32 operates to release gripping force applied by spring 30. Thus, in the event of a hydraulic failure including loss of hydraulic pressure, rod gripping mechanism 26 will maintain the grip on a rod 20. This provides an inherent level of safety as it prevents a gripped rod 20 from being released which has the potential of injuring personnel or damaging equipment.

In this particular embodiment the rod gripping mechanism 26 comprises two commonly controlled and operated grippers 34. As each gripper 34 is of the same construction and operation, for the sake of simplicity, only one of the grippers 34 will be described in detail.

Referring initially to Figure 5 each gripper 34 comprises a spring 30 surrounding a ram 32. Spring 30 is disposed between a retainer 36 and a spring housing 38. Ram 32 comprises a cylinder 40 and a piston 42. Hydraulic fluid is provided to cylinder 40 via a conduit 44 which extends through the retainer 36. Spring 30 surrounds both cylinder 40 and conduit 44. The piston 42 is coupled with spring housing 38 in a manner so that applying pressurised hydraulic fluid through conduit 44 causes retraction of piston 42 into the cylinder 40 and thus compresses spring 30.

Referring to Figures 3a and 3b, each gripper 34 is also provided with a wedge 46 and a pair of jaws 48a and 48b (hereinafter referred to in general as "jaws 48").

The Wedge 46 is coupled to the spring housing 38 and is able to move between the jaws 48a and 48b. In general terms spring 30 is pretensioned to bias wedge 36 to move in between the jaws 48a and 48b causing distal ends of the jaws to pivot inwardly to grip a rod 20 located there between. Operating ram 32 to retract piston 42 into cylinder 40 compresses the spring 30. This releases the bias provided by spring 30 allowing the distal ends of the jaws 48 to pivot outwardly consequently allowing a rod 20 to be released.

The jaws 48a and 48b are held within a jaw housing 50 (see Figures 3a, 3b, 9a and 9b). The jaw housing 50 comprises a pair of plates 52 that are held in a space relationship to each other by mechanical fasteners 54. Each mechanical fastener 54 comprises a threaded stud 56, which extends at opposite ends through the plates 52, a sleeve 58 that is disposed about the stud 56 and between the plates 52, and nuts 60 and 62. The nuts 62 are provided on each side of the sleeve 58 between the plates 52. The drill housing 50 is also provided with a stud block 64 that is disposed on an outside of one of the plates 52 and through which each of the studs 56 extend. The stud block 64 is retained on studs 56 by respective nuts 60, and is provided with through hole 66.

On the inside of each of plates 52 there is provided respective pairs of pivot bosses 68a and 68b (see Figure 9b) on which respsective jaws 48a and 48b are pivotally supported. Mutually facing surfaces 70a and 70b of jaws 48 are curved to a radius corresponding to the radius of rods 20 to enable jaws 48 to grip around a portion, preferably greater than 180°, of an outer circumference of each rod 20.

The rod gripping mechanism 26 is constructed by connecting two grippers 34 together via a plate 72. The plate 72 is provided with a pair of recesses 74 near but inbroad of each opposite end (see in particular Figures 3b and 3d) with holes extending longitudinally from the ends of the plate 72 to respective adjacent recess 74. The jaw housings 50 are attached to the plate 72 by passing ends of the studs 56 distant the nuts 60 through these holes so that ends of the studs 56 are located in the recesses 74. Jaw housing 50 are then fastened to plate 72 by screwing nuts 75 on to the ends of the studs 56 located in the recesses 74.

Each retainer 36 is also attached to the plate 72 and the stud block 64 of a corresponding jaw housing 50 by adjustable fasteners 76a and 76b respectively. An end of fastener 76b distant retainer 36 passes through hole 66 in the stud block 64. An end of fastener 76a distant retainer 36 extends through a corresponding hole formed in the plate 72. These ends of the fasteners 76a and 76b are held in place by respective nuts 78.

Ends of the fasteners 76a and 76b adjacent the retainer 36 are provided with bolts 80 having respective heads that bear against an upper side of the retainer 36 and threaded shanks that engage internal threads formed in elongated sleeves 82 which form part of each fastener 76. The provides the mechanism for adjusting the gripping force provided by spring 32. By tightening (ie screwing in) bolts 80 the force provided by the spring 32 on the wedge 46 increases which in turn increases the force pivoting the jaws 48 together.

Referring to Figures 6 - 8, the rod gripping mechanism 26 is attached to a carriage or trolley 84 by a cylinder mounting clamp 86. The trolley 84 forms part of transfer mechanism 28 enabling rod gripping mechanism 26 to be transferred or moved laterally between tower 14 and bin 16.

The cylinder mounting clamp 86 comprises a rectangular plate 88 which is connected to clamp arms 90a and 90b (hereinafter referred to in general as "clamp arm 90"). One end 92 of each clamp arm 90 is provided with a fixed clamp assembly 93 comprising a clamp block 94 and a clamp half 96. The clamp block 94 and the clamp half 96 are formed with respective semi circular recesses 98 and 100, with clamp half 96 attached to clamp block 94 by a pair of bolts 102.

An opposite end 104 of each clamp arm 90 is formed with a hand operated clamp assembly 106. The clamp assembly 106 comprises a hand operated screw 108 that passes through arm 90 and engages an underlying clamp jaw 110. The clamp jaw 110 is retained from completely unscrewing from the screw 108 by a split pin 112 that passes through a distal end of the screw 108 retaining a washer 114 on the screw 108. Each of: the end of the arm 104; and, the clamp jaw 110, is provided with an arcuate recess.

Plate 88 is provided at each end with holes 116 for retaining hydraulic rams 118. A larger hole 120 is provided between each set of holes 116 to enable a piston of each of the rams 118 to pass through the plate 88 and attach to the plate 72. Thus, plate 72 is held beneath plate 88 by rams 118. This is shown most clearly in Figures 6a and 6b.

Plate 88 is also provided with two further holes 122 in the region between the arms 90 through which a pair of guide rods 124 pass. One end of each guide rod 124 is attached to the plate 72 while the opposite end of the guide rods 124 are coupled together by a link 126.

With reference to Figure 8, the carriage or trolley 84 comprises four shafts 128a, 128b, 128c and 128d (hereinafter referred to in general as "shafts 128") which extend between and are coupled to respective parallel mounting plates 130. Each mounting plate 130 is of a rectangular configuration provided with a inboard longitudinal slot 132. The shafts 128 extend between respective opposite corners of the plates 130. Each shaft 128 is provided with a pair of spaced apart circumferential recesses or grooves 134. The grooves 134 are formed at the same location on each shaft 128. Rollers 136 are rotatably mounted at each end of each shaft 128 on an outer side of mounting plates 130. Support plates 135 are welded between shafts 128a and 128c; and support plates 137 are welded between shafts 128b and 128d. Cutouts or spaces 139 and 141 are provided in plates 135 and 137 for receiving the clamp assemblies 93 and 106 respectively.

The assembly of the rod gripping mechanism 26 and cylinder mounting clamp 86 is attached to the trolley 84 by the fixed clamp assembly 93 and the releasable clamp assembly 106. The fixed clamp assembly 93 of each clamp arm 90 is attached to shaft 128b about respective grooves 134. This is achieved by undoing the bolts 102 to detach the clamp half 96 in seating a respective arm 90 in one of the grooves 134 of the shaft 128b and subsequently rescrewing the clamp half 96 onto the corresponding clamp block 94. The diameter of the hole formed by the recesses 98 and 100 is marginally greater than the outer diameter of groove 134 to enable the cylinder mounting clamp 86 to be pivoted about shaft 128b. End 104 of each arm 90 is releasably attached to a corresponding groove 134 on the shaft 128a by the releasable clamp assembly 106. Each flange 142 is formed with a lug 166 having a hole 167, and a lever arm 168 which extends in the general direction of an associated beam 140. Lug 166 is located between beam 140 and lever arm 168.

The transfer mechanism 28 comprises the trolley 84 together with a frame 138 (see in particular Figures 2, 4a - 4d, and 10). The frame 138 is substantially rectangular in shape having a pair of longitudinal beams 140 which are coupled together at one end by respective flanges 142 and a cross bar 144 connected therebetween. Opposite ends of beams 140 are coupled together by a cover plate 146. A further cross bar 148 extends across and is coupled to the beams 140 a short distance from the cover plate 146. A track 150 is coupled to an inside of each beam 140. The rollers 136 of trolley 84 ride on opposite sides of the track 150 and retain the trolley 84 on the frame 138. Spacer legs 152 extend from the beams 140 on a side opposite the cover plate 146. When the transfer mechanism 28 is in use transferring a rod 20 between the tower 14 and the rod bin 16, legs 152 bear against a side of tower 14 as shown in Figure 2.

The transfer mechanism 28 incorporates a chain drive system 154 which is coupled to the trolley 84 enabling the trolley 84 to be traversed along the track 150 and thus between the tower 14 and the rod bin 16. The chain drive system 154 comprises endless chains 156 (see Figure 2) which: at an end near the cross bar 148 turn about respective idler cogs (not shown) fixed to the frame 138; and, at an opposite end near the cross bar 144 turn about drive cogs mounted on a drive shaft (not shown). The chains 156 also engage cogs (not shown) pivotally attached to the mounting plates 130. A hydraulic motor 158 is held by a bracket 160 attached to one of the flanges 142. The motor 158 5 provides drive to the drive shaft to turn the chains 156. Housing 161 extends between flanges 142 for housing the drive shaft.

Flange 138 is pivotally attached to mounting plate 162 of tower 14 by pivot pins that pass through the holes 167 and plates 162. Rams 164 are connected 10 between the lever arms 168 and ends of plate 162 distant tugs 166.

In the depicted embodiment the plate 162 is attached to an outside of the bin 16. By appropriate operation of rams 164, frame 138 and thus transport mechanism 28 can be moved (i.e. swing) between an operational position

> 15 shown in Figures 1 and 2 where the transfer mechanism 28 extends across the tower 14 and bins 16 enabling rods 20 to be transferred therebetween; and, a second position (not shown) where the transfer mechanism 28 is spaced from bin 16 and the tower 14 enabling rods 20 to be loaded into or removed from the tower 14 or the bin 16. It would be appreciated that when the transfer

20 mechanism 28 is in the operational position, the frame 138 by and large retain the drill rods 20 within the bin 16.

An example of the use and application of the rod handling system 12 will now be provided.

25

Assume that the drill rig 10 is being readied for transport to site and subsequent use for drilling. The drill rig 10 may be in a state where both the tower 14 and the bin 16 lay horizontal side by side on the vehicle 18. Rod gripping mechanism 26 is in a storage position shown in Figures 4a - 4d where

30 releasble clamp assembly 106 is released from shaft 128a of trolley 84 enabling cylinder mounting clamp 86 and thus rod gripping mechanism 26 to pivot about shaft 128b so that grippers 34 and rams 118 lie flat against and parallel to frame 138. If it is assumed that the rod bin 16 is empty, rams 164 can be operated to swing the frame 138 away from the bin 16 to enable a supply of

35 rods 20 to be loaded into the bin 16. When the bin 16 has been filled with rods 20, rams 164 are operated again to swing frame 138 to lie across both the tower 14 and the bin 16. The drill rig 10 is then driven to site. Prior to elevating the drill rig 14 and the bin 16, rod handling mechanism 26 is pivoted about shaft 128b and the clamp 106 re-engaged with shaft 128a so that the rod gripping mechanism 26 is now in a use position shown in Figures 1 and 2. In order to commence drilling an operator utilising controls that are either mounted on the rig 10 or alternately mounted on a mobile stand that can be carried by the rig 10, operates transfer mechanism 28 to traverse rod gripping mechanism 26 to a location in front of bin 16 where grippers 34 are aligned with a rod 20. The operator operates: rams 32 to retract wedge 46 from between the jaws 48 allowing the jaws 48 to pivot outwardly; and, rams 118 to advance the rod gripping mechanism 36 into the bin 16 to a location where the jaws 48 are located about a rod 20. The operator then relieves hydraulic pressure from rams 32 allowing the spring 30 to bias the wedge 46 to move in between the jaws 48 causing the jaws 48 to close over and grip the rod 20. Next, rams 118 are operated to retract the rod gripping mechanism 26 from the bin 16 to a position where the gripped rod 20 is disposed in front of the bin 16. Clearance is provided between the frame 138 and the bin 16 and tower 14 by virtue of the legs 152 and the lugs 166 on the flanges 142. The transfer mechanism 28 is now operated to move the rod 20 laterally, without changing its inclination, to lie in front of tower 14 in alignment with the rotation head. Rams 118 are again operated to now move the rod 20 inwardly of tower 14 to lie directly underneath a drill thread under the rotation head. The drill thread is screwed into the rod 20 and once the thread is made up, rams 32 are again operated to compress the springs 30 allowing the jaws 48 to be released from the rod 20. The rams 118 are operated to retract gripping mechanism 34 from tower 14 and transfer mechanism 28 operated to move the rod gripping mechanism 26 out of the way of tower 14. The drill may now be operated to drill into the ground.

The rod handling system 12 enables a driller to load the rods 20 while drilling without aid from an offsider who normally would be conducting sampling or other duties. When rod pulls are required the offsider can operate the rod handling system 12 and transfer the rods from the tower 14 to the bins 16 while the driller pulls the rods from the hole.

Now that embodiments of this invention have been described in detail it will be apparent to those of ordinary skill in the art that numerous modifications and variations may be made without departing from the basic inventive concepts. For example, the rod gripping mechanism 26 is depicted as comprising two grippers 34 which grip the rod 20 at two spaced apart locations. However in alternate configurations, a separate numbers of grippers 34 may be used, for example 1 or 3. Further, while rams 34 are described as applying a release force for the jaws 48 compressing the springs 30, different types of actuators such as pneumatic rams or electric screw jacks may be used for this purpose. In an alternate configuration, solenoids may be used in place of the springs 30 and rams 32 to apply and release the gripping force. In such an embodiment, the solenoids may be arranged to ensure that the grippers 34 maintain grip on a rod 20 in the event of a loss of electrical power. In a further variation, the chain drive system 154 incorporated in the transfer mechanism 28 can be replaced with other systems that can facilitate the translation of the rod gripping mechanism 26 between the tower 14 and the bins 16. For example, hydraulic or pneumatic rams or electric screw jacks can be used for this purpose.

All such modifications and variations together with others that would be obvious to persons of ordinary skill in the art are deemed to be within the scope of the present invention the nature of which is to be determined from the above description and the appended claims.