CA1117518A - All terrain drill unit - Google Patents

Abstract

ABSTRACT

In an all terrain drill having a mobile chassis and a drilling head on a subframe capable of operation in various attitudes relative to the chassis, both the chassis and the drilling head are driven hydraulically by a vari-able displacement pump which operates alternatively either propulsion motors or a drill motor, drive from the motor to the drill being through a change-speed gearbox and direct gearing. Other hydraulic functions are powered from a separate pump.

Description

1~7S~

This invention relates to an all terrain drill unit of the ~ind comprising an all terrain vehicle chassis carrying a drilling ma3k which may be movea between a horizontal position overlying the chassis ~nd a vertical position at one end of the chassi~, the vehicle chas~is being used to bring the drill to a desired location and also carrying a power source for the drill.
In conventional unit~ of this kind, it has been known to carry out various of the vehicle functlon~ using hydraulic motors or actuators, but the relatively high cost of such techniques has restricted their use to selected functions - only. We have found however that the advantages gained by using hydrostatic drives for essentially all of th0 vehicle functions outweigh the extra cost involved, particularly in the respect that with proper application of conventional hydrostatic engineering technique~, we find that a more versatile and eff~ctive unit can be produced which is nevertheless substantially easier to operate than conventional units, As compared with conventional units, a drill unit in accordance with the invention, in which all major functions are performed hydraulically, and in which the controls for these functions are appropriately integrated and interlocked, can have the advantages of being able to drill at any angle to the vertical ~available conventional mobile drills of this type can only drill vertically), of beiny exceptionally simple to operate (most conventional units 7~

require extensive operator training), and reliability and easy mainterlarlce in that all o~ the major drive parts may be readily available standard items. TO thi3 end, hydraulic drive units are used both to pro~ide traction for the vehicle chassis and drive for the drilling unit;
the use of a hydraulic drive in the drilling head eliminates the need for the mechanical drive conventionally used for this purpose and enables the drilling head to be operated at any angle to the vertical at full efficiency.
Moreover~ the use of hydraulic operation enables exceptionally simple controls to be utilized. In accordance with a further feature of the inven~ion, a single pump ~ontrolled by a lever with a central neutral position is preferably utilized to determine the rate of forward and reverse movement of the vehicle in accordance with the degree of forward or rearward movement of the lever which is connected to appropriat~
proportioning valves in hydraulic circuits of the vehicle.
By means of another control, the output of this pump may be switched so that instead of determining forward and reverse movement of the vehicle, it determines forward or reverse rotation of the drill. In a preferred arrangement, the control lever is duplicated ~oth in a driving cab of the vehicle to control movement of the vehicle and at a control console adjacent the drilling head at the rear end of the vehicle to control rotation of the drill.
In accordance with a further preferred feature, and in order to allow for the different drllling speed ranges required for different types of drilling operation, the hydraulic drive to the drilling head incorporate~ a change speed gearbox which may have a hydraulically controlled shift. Preferably the gears are ~elected by two po~ition selector~ which are both normally centered in a neutral position by springs and displaced into gear ~el~cting position~
by independently controlled hydraulic cylinders so that the selectors may be operated in any d~sired combination.
According to a further preferred fea~ure of the invention, each wheel of the vehicl~ is driven by an independent hydraulic motor, and a flow limiting valve is provided in the -qupply line to each hydraulic motor ~o that in the ~vent of any wheel slipping or lifting clear of the ground, power will still be available at the other wheels, and tho ~lipping wheel will not cpin uncontrollably and thus wor~en the lack of adhesion. Drive power may be applied either to the wheels of only one axle, or to all four wheels; the application of drive to all four wheels may be achieved by hydraulically controlling variable capacity drive motor~ on two o the wheels to change between idling ~0 and powered states.
The drilling mast is preferably pivotally mounted on a sub-frame which may ~e moved horizontally by hydraulic actuating means to provide exact positioning of the drill.
The vehicle chassis is preferably further equipped with three hydraulically extensible legs whereby, on reaching a de~ir~d drillinq station, it may be anchored firmly on the ground and appropriately l~velled~ The drilling ma~t, as well as hydraulic dri~e mean~ for drill bits and hydraulic means for advancing the drive means xelative to the mast as drilling proceed~, may also have associated with it hydraulic winches operating conven~ional block and tackle means for handling drill bits, corers and the liXe.
Preferably the drill head itself comprises a hydro-static motor, a change speed gearbox, and a reduction gear drive to an output shaft through which the drilling torque is applied. Although contrary to normal practice, the use of geared drive throughout instead of the more usual chain drive has the advantage of providing a compact assembly in which adequate thrust bearings may readily be applîed to the output shaft. It i5 found in practice that the drilling heads of such drill units are subjected to considerable abuse, and the compact assembly which can be provided by a geared drive can more easily be engineered to withstand the abnormal stresses to which the head may be subjected when used for purposes which it was not intended.
Further features and details of the inven~ion will be apparent from the following description of a preferred embodiment of the invention, SHORT DESCRIPTION OF THE DRAWINGS
Figure 1 is a plan view of the drilling unit, Figure 2 i5 a side elevation of the unit, Figure 3 is a rear elevation of the unit, ~7~8 Figure 4 is a fragmentary vertical section on the centre line of a rear wheel of a vehicle chassis of the unit, Figure 5 is a view from the direction of the arrow F
in Figure 4, with the wheel and parts o~ the wheel hub removed for the sake of clarity, Figure 6 is a fragmentary vertical section on the Fro ~t centre line of a ~e~r wheel of the vehicle chassis, Figure 7 is a fragmentary plan view from the direction of the arrow E in Figure 6, j 10 Figure 8 is a schematic diagram of the hydraulic circuits of the unit.
~eferring now to Figures 1 to 3, the drill unit is built upon a ladder-typ~ chassis comprising longitudinal members 2 and cross members 4 and 6, supported on front and rear wheels 8 and 10. Outrigger portions of the cross members 4 and 6 support a cab 12, fenders 14 and 16 and lockers 18 for carrying drills and other accessories. Guided for longitudinal motion relati~e to the rear of the chassis upon a bed formed by the longitudinal members 2 is a subframe 20 having uprights 22 which support, through pivots 24~ brackets 26 attached to a cradle 28 forming part of a drilling mast indicated generally by the reference 30. The mast is normally supported in a horizontal position over the chassis by additional rests 3~ and 34 carried by the chassis.
~lso carried on the chassis frame is a prime mover in the form of an internal combustion engine 36 supplied with fuel from a tank 37 and coupled to several hydraulic 75~l~

pumps, these pumps being shown generally as an assembly 38.
The various ~unctions of the drilling unit are best described in conjunction with their associated hydraulic circuits, as shown in Figure 8. A primary hydzaulic circuit, providing motive power for the vehicle chassis of the unit and for a drilling head 40 carried by the mast 30 is shown on the right hand side of Figure 8 and comprise~ a variable displacement pump unit 42 forming part of the assembly 38.
A secondary hydraulic circuit supplied by a constant displace-ment pump 44 incorporated in the assembly 38 comprises all of the auxiliary functions associated with the drilling function of the rig. These various auxiliary functions will be described further below. An auxiliary pump 46 is provided for use during movement of the vehicle to provide the steering function.
~eferring now in more detail to Figure 8, the pump unit 42 includes a variable displacement pump 4~ having output lines SO and 52 and receiving input oil from a return line 5 . In order to provide various control ~unctions described below, an auxiliary pump 56 is provided drawing oil through a filter 5~ from a tank 60 (see also Figures 1 and 21.
The various sumps shown in the diagram are all returned to this tank60 via an oil cooler 72 tsee Figures 1 and 2) and a return line filter 70. The output pressure from pump 56 on the line 66 is controlled by means of a relief valve 68.
Other details of the pump unit, apart from the control ~unctions discussed below, need not be described in detail since the ~75~

unit shown is a conventional proprietary item (Eaton trans-mission pump No. 5420 024).
The lines 50 and 52 are connected to a change-over valve 54 operated by a double acting actuator 73. The control pressure for the actuator 73 is applied through t~o control lines 74a and 74b either to the line 66 or to a return line 76 by means of a man~lally operated changeover valve 78.
When the pressure from line 66 i5 applied to the line 74b, the valve 54 is moved to the opposite position from that shown, and the lines 50 and 52 are connected by lines 80 and a2 to a constant volume hydraulic motor unit 84, which drives the drill head 40 through a gearbox 86 and reduction gears 87 and 89. overloads on the gearbox and motor transferred back from the drill head are prevented by back-to-back pressure relief valves 88.
When pressure from the line 66 is applied to the line 74O, the valve 54 assumes the position shown, thus connecting the lines S0 and 52 to fixed volume hydraulic motors 94 and variable volume hydraulic motors 96 through lines 90 and g2. The motors 94 drive the front wheels 8 through reduction hubs 102, and the motors 96 drive the rear wheels 10 through reduction hubs 104 (see Figures 4 and 5). A ma~ually operated changeover valve 108 connected to the line 66 controls double acting actuators operating the flow controls on the motors 96 so as to move these between neutral and full flow, so as to provide either two or four wheel drive. The maximum flow of oil to the motors 94, 96 driving the individual wheels is limited by flow re~trictors 106. In the event of one driven wheel losing adheqion, the presence of the flow reqtrictor 106 a~sociated w.ith that wheel prevents its associated motor from hogging the entire oil ~upply, and ensures that traction is maintained on the other wheel or wheels. Obviously, the reiative calibrations of the various restrictors may be varied should it be desired to redistribute the maximum oil flows permitted to each wheel.
The line 66 also supplies, via the valve 78 and line 114, a brake valve 116 by means of which hydraulic pressure may be applied to or released from cylinders 118 operative to release normally applied disc brakes 120 (see Figure 5) acting on brake discs 122 at~ached to the hubs 104 (see Figures 4 and 5).
As will be seen from Figures 4 and 5, the hubs 104 and motors 96 for the rear wheels 10 are supported by brackets 124 on the longitudinal members 2 o~ the chassis. Since pressure is applied via the valve 78, the brakes can only be released when this valve is positioned so that the valve 54 applies fluid pressure to the wheel motors 94, 96.
The valve 116 is actuated by a cam 110 having a centre dwell and ganged with a two way proportioning valve 112 which also has pressure applied thereto via the valve 78 and the line 114. The arrangement is such that the valve 116 is closed when the proportioning valve is closed, and open when the proportioning valve is opened in either direction. The proportioning valve acts upon opening so as to move a control valve 111 in the pump unit 42 proportionately in a corresponding 5~8 direction so a~ in turn to set up a proportionate pres~ure differential between the line~ S0, 52, the sense of the differential being in accordance w.ith th~ direction of opening of the valve 112. Hence ~o~ement of the valve 112 out of its closed po~ition releases the brakes 120 and progres~ively applies power to the vehicle wheel~ so as ~o drive thc vehicle in either direction according to th~ direction o movement of the valve.
When the valve 78 i9 rever~ed, control pressure is applied to a two way proportioning valve 113 ganged with the valve 112, which then operates .in the same way as the valve 112 to apply the variable and reversible differen~ial output from the pump 48 to the drill head motor 84. Two way check valve~ 115 act to i~olate that one o~ the valve~ 112, 113 to which pressure is not applied.
Referring now to the lower centre portion of ~igure 8, the pump 46 draws oil from the tank 60 through a filter 59, and delivers it to a steering control unit 126 (see also Figure 2) through a line 128 in which the pressure is controlled by a relief valve 130. The steering control unit 126 is conventional, and selectively supplies oil to two steering actu-ators 132 (see Figure 7). Referring to Figures 6 and 7, the actuators 132 act between a bracket 134 and steering knuckles 136 welded to the sides of cylindrical drums 138 which house the motors 94. Diametrically opposite points at the top and bottom of the drums are connected by king pins 140 and forks 142 to a front axle 144 to the centre point of which the bracket 134 is attached. The knuckles 136 are connected by a tie rod 146 ~30 a~3 to complete an Ackerman steering linkage, and the bracket 134 i~ pivotally connected to a cross ~em~er 4 of the chassi~ by a pi~ot pin 148 so as to permit the axle to rock latera lly relative to the chassis. Since the rear wheel~ are ~ixed relative to the chass is, this enables the front axle to move to accommodate unevenness in the terrain without influencing the steering.
The s~eering unit 126 is connected to a steering wheel 127 appropriately positioned relative to a driver's seat 150 in the cab 12, and an appropriate feedbacX connection is established between the front wheels and ~he steering unit 126 to control the pressure applied to the cylinders 132.
Referring now to the left hand portion of Figure 8, the pump 44 draws oil from the tank 60 through a filter 61, and supplies pressurized oil via the line 152 to the various auxiliary functions associated with operation of the unit in its drilling mode. oil from the line 152 is applied to the various auxiliaries by means of valves assembled into banks 154, 155 and 156. These valve bank a~semblies are mounted on a control panel 158 at the rear of the vehicle chassis adjacent the operating position of the drilling ma3t 30~ The control panel 158 also carries a lever 161 operating the valve~ 112 and 113 for the variable volume pump unit 42 via a cable, a further lever 160 also operating the valves 112 and 113 via a cable 163 being provided in the cab 12. The control function is such that in the mid position of the control lever~ 160, 161 the output pressure from the pump 48 is the same on both 5~3 lines 50 and 52, and moveme~t in oppo~ite direction~ from the central position produces a pre~ure differential between the two lines in a sense depending on the direction of movement of the lever. The valve 78~ determine~ whether the levers 160, 161 control the drill head 40 or the motors 94, 96.
All the auxiliary functions save the water pump referred to below are powered by double a~ting li~ear hydraulic actuators or reversible hydraulic motors. The individual valves in the banks 154, 155 and 156 each have three po~itions, a first position in which one output line is connected to the line 1~2 and the other line to a return line 164, an intermediate position in which both output lines are either blocked, and a third position in which the one line is connected to the line 164 and the othex line to the line 152.
The valves in the bank 156 control various functions mainly associated with the operation of the drilling head 40.
A valve 166 controls two actuators 1~8 which move the head 40 longitudinally of the ma~t 30 on guides 170 ~see Figure~
1 and 2). A second valve 172 is connected in parallel with the valve 166 ~ut is in series with a flow restrictor 174 and a relief valve 173; the valve 172 may be used when it is desired to move the drill head at a lower rate, as during actual drilling, whilst the valve 173 limits the thrust A applied to the drill. A fourth position of the vaLve L~
allows the actuators to permit the drill head to move downwards under gravity, but not in the opposite direction.

75~3 Valve~ may be provided to control double acting cylinders which operate th~ ~electors in the change ~peed gearbox 86 go a3 to alter the ratio of the gearing between the motor a4 and the output shaft 1.84 of the drill head 40, or th~ge selector~ may be operated manually.
The valve 186 controls a cat head winch 188 mounted on the cross member 6, which is used in conjunction with a cat head 190 in the fitting and removal of drill bi~s and the like in and from the drilling head 40.
Two valves 192 control two ~oom winche~ 194, and a valve 196 controls a further winch 198 on the carriage 20.
All of the~e three winches are used in connection with the handling of drill bits, tubes, corer~ and the like in asqociation with the drillin~ ma~t.
Considering now valves comprised by the valve bank 155, t~e valve 202 controls a levelling jack 204 at the front of the vehicle, whilst valves 206 and 208 control levelling jacks 210 at the rear of the vehicle and extending through the cross member 6.
A valve 212 in the bank 156 controls an actuator 214 controlling longitudinal movement of the carriage 20, and a valve 216 controls two actuators 218 acting between the platform 20 and the bracket 26 so as to tilt the ma~t 30 to any desired angle.
The valve 220 in the bank 154 controls an additional winch 222 at the front of the vehicle, and the valve 224 in the bank 156 control~ a hydraulic motor 226 driving a water pump 228 used either to supply water for use during a drilling ~ 13 -~7S~3 operation, or for extra~ting exces~ water as nece~s~ry.
A ~ariable restrictor ~lve 230 is provided in ~eries with the pump motor so as to control the pump output.
In use, the drilling unit is driven to a drilling site in the condition 3hown in ~igures 1 to ~, that i~ with the drilling mast resting horizontally on ~he supports 32.
The valve 78 i~ positioned so that khe output of the ~ump 48 is applied to the wheel motor~, the valve 108, which is located in the cab, ~eing positioned either so as to cause the rear wheel motors 96 to idle, or to cause both the motors 96 and the front wheel motors 94 to be powered if four wheel drive is required by terrain conditions. The velocity of the vehicle i5 controlled by the lever 1~0 in the cab, which is disposed so that forward movement of the lever causes the vehicle to move forward at a rate dependent on the degree of movement of the lever, and rearward movement causes the vehicle to move rearward according to the degree of rear-ward movement of the lever. Any additional braXing effort which may be required to bring the vehicle to a halt is automatically applied ~y the brakes 120 when the pressure in the brake cylinders is released by the valve 116 as the lever 160 is returned to its centre position. ThuS the brakes cannot be released unless the vehicle is powered~ On arrival at the site, the vehicle is manoeuvered, using either the lever 160 or the lever 161, a~ is convenient, so that the rear of the mas~ 30 is in line with the desired point of entry of the drilling to be made, and the operator then reverses the ~alve 78.

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The levelling jack~ 204 and 210 are extended so a3 to support the vehicle firmly on the ground and level the cha3sis, using /~5 the appropriate con~rol valve~ in the bank ~, and the con~rol valve 216 is used to extend the actuators 218 to whatever extent is necessary to bring the mast 30 to a desired drilling angle~ This wiil normally be vertical, with the cradle at 28 adjacent the supports 22, but it i~ an important advantage of the unit that other angles may equally readily be employed if desired. When the required angle has bee~ reached, the ~ast is locked in posi~ion by returning the valve to its intermediate, locked position Drill bits and the like, according to the operation being carried out, may be fitted to the drill head 40 using the various winche~ 188, 134 and 198, and an appropriate ratio selected in the change speed gearbox 86 by use of hydraulically or manually operated selectors. The lever 161 may then be used to control clockwise and anti-clockwise rotation o the drill shaft 184 in a similar manner to that described with reference to the forward and rearward movement of the vehicle, the valve 78 having previously been operated so as to connect the pump 48 to the motor unit 84. The drill may be advanced to a drilling position by means of the valv~ 166, and precisely positioned over the required point of entry by using the valve 212 to control the actuator 214 moving the carriage 20.
During drilling, the drill may be advanced by tha actuators /~
~e under the control of the valve 172, or by gravity under the control of the ~alve ~68 in its fourth position~ When it is required to change or extend a dx.ill or the like, the drill head may be withdrawn 11p the mast by the actuators J~
h~ e under control of the valve 166, and the nece5sary exchange of bits or insertion of extensions handled using the variouc winches~ Any nece~sary supply or removal of water or mud during the drilling operation can be carried out using the pump On completion of the drilling operation, the drills and the like may be stowed in the lockers 18, the platform 20 retracted, and the drilling mast returned to its horizontal position~ the jacks 204 and 210 retracted, and the valve 78 again reversed so that pressurized oil is available for supply to the wheel motors so that the unit may be moved to another drilling site or returned to ~ase. The winch 222 may be utili~ed if necessary to assist in crossing particularly difficult terrain, or in clearing sites prior to drilling.

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Claims (6)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In an all terrain drill unit comprising an all terrain vehicle chassis, propulsion means for said chassis, a drilling mast mounted on the chassis for move-ment between a horizontal position overlying the chassis and a vertical position overhanging the chassis, a drilling head carried by the drilling mast, and a power source on the chassis for the drilling head, the improvement wherein first hydraulically operated actuator means is provided linked to the drilling mast and chassis for moving the for-mer to any location between its horizontal and vertical positions inclusive, second hydrualically operated actuator means is provided linked to the drilling mast and the dril-ling head for moving the latter longitudinally of the mast, third hydraulically operated actuator means is provided on the vehicle chassis to locate the latter in a desired drilling attitude, and a first hydraulic pump is fluid linked to said actuator means to supply pressurized hydrau-lic fluid thereto, wherein the power source for the drilling head is a second variable displacement hydraulic pump which is alternatively a power source for the propulsion means for the vehicle chassis and is controllable independently of said first hydraulic pump, wherein the actuator unit for said drilling head is a reversible drive motor and the propulsion means for said vehicle chassis are a plurality of wheels each associated with a reversible hydraulic drive motor, and wherein control valve means are provided through which the second hydraulic pump is selectively fluid linked to said motors for said drilling head and said vehicle chassis, said control valve means comprising a first con-trol valve means adapted to reverse said motors and having a neutral position, and second control valve means directing fluid either to said drill head motor or to said wheel drive motors.

2. A unit according to Claim 1, wherein the dril-ling head further comprises a change-speed gearbox receiving an input from the drive motor, and a reduction gear drive applying the output of the gearbox to an output shaft, the drive being transmitted from the motor to the output shaft through directly meshing gear wheels.

3. A drill unit according to Claim 1 or 2, wherein the unit has a driving cab on said chassis and a control unit on said chassis adjacent said drilling head and remote from the driving cab, and said first pump and said first control valve means have manual control means duplicated in said cab and at said control unit.

4. A unit according to Claim 1, wherein a flow limiting valve is included in a hydraulic supply line from the control valve means to each wheel drive motor.

5. A unit according to Claim 4, wherein the motors associated with certain of said wheels are variable capacity motors, whereby the torque applied to said certain wheels may be changed relative to the torque applied to the remainder of said wheels.

6. A unit according to Claim 1 or 2, wherein the drilling mast is mounted on a sub-frame, and hydraulically operated actuator means, fluid linked to said first hydrau-lic pump, is provided between the chassis and sub-frame whereby to control the position of the latter on the chassis.