NO137021B - PROCEDURE WITH WOOD AND DEVICE FOR MOUNTAINS AND EARTH DRILLING. - Google Patents

Description

This invention relates to a method and a device for rock and soil drilling of a number of boreholes to a predetermined, preferably flat bottom surface. This bottom surface can e.g. be a surface that is close to the surface of a road to be built. However, the invention is not limited to road construction, but can be advantageously used in all cases where the drilling is to take place to a predetermined bottom surface.

The currently used method includes a time-consuming measurement of each borehole to determine its necessary depth, which must also be marked close to the point where the drilling is to take place. To reach the required depth, a drill rod consisting of one or more rod sections is used. In most cases, drilling must be stopped when the last rod sec-

tion is only partially penetrated into the substrate. If the drilling is not carried out at a sufficient depth, the subsequent blasting will leave standing rock formations. To remove these, new drilling and blasting must be carried out, but first

the already blasted rock mass is carried away, and there is a great danger that the loading machines' vanes will be damaged when they hit the standing rock formations. In order to avoid these risks of damage and to avoid the time-consuming work of post-blasting and subsequent further planning, it is essential that drilling

is not interrupted until the required hole depth is reached. In order to

to be sure of this, it is common for the operator not to stop drilling until the last rod section has been drilled all the way into the sub-

got. This entails unnecessary drilling and blasting costs.

The purpose of the invention is to provide a simple and safe

ker indication of how far the drilling work has reached in relation to a reference surface defined by electromagnetic radiation, at which the drilling can be interrupted when the predetermined bottom surface is

achieved, which according to an advantageous embodiment of the invention occurs automatically.

The peculiarity of the method according to the invention is that a reference surface defined by electromagnetic radiation is created parallel to the aforementioned bottom surface, that the distance is measured in a direction common to all holes between the reference surface and the point at which drilling begins, that the thus measured distance is added the component of the borehole depth in the aforementioned direction and that the drilling is interrupted when the sum indicates that the bottom surface has been reached.

The device for carrying out the method according to the invention is of the type that comprises a drilling machine driven along a feeding device for drilling holes to the bottom surface, and a recording device connected to the feeding device for recording the forward feed of the drilling machine along the feeding device, and the peculiarity of this device is a device for producing a reference surface defined by electromagnetic radiation parallel to said bottom surface, and devices connected to the recording device for recording the sum of the distance in a given direction between the reference surface and the point at which the drilling begins and the component of the borehole depth in the said direction .

These and other features of the invention will appear in more detail from the drawings, if fig. 1 shows an embodiment with independent reference plane searchers, fig. 2 shows another embodiment, in which the reference plane finder is mounted on the feed beam of the drilling unit, fig. 3 shows the embodiment according to fig. 1 with a control system adapted to this, fig. 4 shows the embodiment according to fig. 1 with a simplified control system adapted to the same, and fig. 5 shows the embodiment according to fig. 2 with a control system adapted to this.

As shown in fig. 1 and 2, where a reference surface 102 is produced by a rotating radiation source 101 such as e.g. can be made up of a laser made as shown in SV-PS 34 7 351. The beam source is arranged so that the reference surface 102 is parallel to the predetermined bottom surface 103. For the drilling work, a drilling unit is used which consists of a chassis 104 with an outrigger arm 105, on to which a feed beam 106 for a rock drilling machine 107 is mounted, to be driven along the feed beam 106 by a feed motor 109 via a chain or a screw in a well-known manner. A drill rod 108 is connected to the drilling machine 107. In the embodiment according to fig. 1, a stand-alone reference level finder is used which consists of a stand J11, a telescopic mast 112 and an arm 113 for sensing the level of the point 99 on the substrate 100, where drilling is to begin. The mast 112 is provided at its upper end with a photodetector 116 which consists of a number of photocells, e.g. such as are manufactured by "Siemens" under the designation BPY63 and which are appropriately mounted so that the radiation source 101 can be sensed regardless of the horizontal direction of incidence. The photodetector 116 is appropriately provided with simple plastic optics for limiting the vertical sensitivity range, as well as with a filter adapted to the color of the radiation source.

This reduces the effect of e.g. sunlight. The stand 111 comprises reversible drive devices for the mast 112 and the arm 113. Thus, e.g. the mast is driven upwards by its interior being exposed to a liquid pressure and downwards by a pressurized fluid motor over a line attached to the mast top pulling the mast together. The arm 113 can be driven by a reversible pressure fluid motor or electric motor. To control the supply of pressure fluid, electrically controlled valves are used which are assumed to include amplifiers or relays, so that they can be operated by the signals obtained from logic circuits. To the drive devices of the mast 112 and the arm 113 are connected pulse-producing sensors. These can e.g. be made with rotating magnets that affect tungre-lés or so-called "logcell elements". The feed of the drilling machine 107 is measured in a similar way. The arm 113 is movable between an upper limit position 114 which is at the same level as the lower limit position of the photodetector 116, and a lower limit position 115. The device according to fig. 2 differs from that of fig. 1 only in that the mast 122 is mounted on the feed beam 106. The mast 122 is driven by a motor 121.

With those in fig. 1 designations used, the connection is obtained

where A denotes the distance between the reference surface 102 and the bottom surface 103, H the distance from the limit position 114 to the attachment point 99, D the depth of the borehole and v the angle between the drilling

gene and the plumb line.

With those in fig. 2 terms used, the connection is obtained

In this case, H and K are measured in the drilling direction. Here, K is the constant distance from the lower limit position 120 of the photodetector 116 to the position point 99.

The drilling machine 10 7 is in fig. 3 shown with an electrically controlled valve 47 that interrupts the power supply, which interrupts the pressure fluid supply through the line 48 to the drilling machine's percussion when a voltage, logical 1 signal, is applied to the input 49. The valve 47 is assumed to comprise an amplifier, whereby control by means of of logic signals is possible. The stand 11 comprises a number of indicators 19, 21, 30, 31 and 32 as well as two pulse-producing sensors 91 and 2, which is shown by line 95. The indicator 19 gives a logical 1 signal, also called signal, on the output when the arm 113 hits the ground. The indicator 21 gives a signal at the output when the mast 112 is in its highest position, which can be adjustable if desired. The indicator 30 comprises the photodetector 116, amplifiers with filters for suppressing unwanted signals, as well as an external device, e.g. a Schmitt trigger, which gives a signal on the output when the photodetector 116 detects the radiation source 101. The indicator 31 gives a signal on the output when the arm 113 is in its upper limit position 114. The indicator 32 gives a signal on the output when the photodetector 116 is in its lower limit position 114. The sensors 91 and 2, which are connected to the mast and arra motors, have two outputs UP and DOWN. These transducers provide two phase-shifted pulse trains, whereby the direction of rotation of the transducers can be sensed. The sensors comprise pulse-shaping elements, e.g. monostable flip-flops, and therefore gives logic 1 pulses with constant duration on either output UP or output DOWN depending on the encoder's direction of rotation. UP and DOWN denote "+" respectively.

"-" according to practice and must therefore not be confused with what is °PP and down on fig. 1.. With the rotation motor 109 or the one driven by the same chain or screw, a sensor 3 is connected which is of the same type as the sensors 91 and 2. This is indicated by the line 97. An angle sensor 26 is connected to the feed beam 106, as indicated by the line 98.. This donor can either be executed thus

that it gives a signal that is proportional to the angle v or so that it gives a signal that is proportional to cos v. The sensor can also be replaced with a thumb wheel switch. The feed beam 106 is provided with a drill support 110 which comprises a tongs 33 equipped with an indicator, by means of which the drill rod 108 can be held firmly. The indicator 33 gives a signal at the output when the tang grips the drill rod. The line 9 6 marks the indicator's 3 3 location. Other electronics are mounted on the drilling unit's chassis 104. The control electronics are mainly made up of integrating circuits and shown in the form of a logical connection diagram. In addition to the already mentioned indicators and encoders, the control electronics include three summing circuits 4, 5 and 6. These have two inputs and one output and work in such a way that each pulse on each input produces a pulse on the output regardless of the relative timing. Also included are three UP/DOWN calculators 7, 8 and 9 which are equipped with a number of inputs and outputs, of which only those that are used are shown. To simplify the description, it is assumed that the calculators react to logical 1 pulses and give logical 1 pulses at the outputs. An exception, however, is input LOAD on calculator 9, which is fed with logic O pulses. The construction of the calculator must be taken into account when using commercially available calculators, which is most simply done by providing certain inputs and/or outputs with diverters. Pulses applied to input UP increase the value stored in the calculator. Pulses applied to input DOWN reduce the value stored in the calculator. When the value becomes zero, a signal is received at output BORROW.

When input LOAD on calculator 9 is supplied with a logic 0 pulse, the value stored in calculator 7 is transferred to calculator 9, which is marked by arrow 45. The value stored in calculator 7 is not affected by this. The multiplier circuit 11 multiplies the incoming number of pulses from the drill length encoder 3 with the value cos v which is either obtained directly from the encoder 2 6 or, if this gives the angle value, produced in the multiplier circuit 11. The system includes three electromechanical pulse calculators 12, 13 and 14 which can be replaced with electronic calculators with a digital display. The calculators 12 and 13 are equipped with a manual reset 81 respectively.

82. The calculator 14 contains two parallel-connected digitizers,

one of which is equipped with manual preset 83. Pulses arriving at input 43 count down the preset mechanism and synchronously count up the other digit mechanism. When pre-

the employment agency receives the value zero, a signal is received at output 44.

With the help of the pull magnet 80, the two numerals are restored simultaneously. The traction magnet 80 is assumed to include an amplifier, whereby operation by means of logic signals is made possible. The pulse generator 24 delivers continuous pulses whose length and frequency are adapted to the calculator 14. The system includes two monostable flip-flops 28 and 29. These give output 1 a logical 1 pulse of a certain length and output 0 a logical O pulse of the same length when the voltage on the input changes from logic 0 level to logic 1 level. The system includes seven SET/RESET flip-flops 10, 15, 16, 17, 18, 20 and 27. These provide a constant logic 1 signal on output 1

and remaining logical 0 signal on output 0 after receiving a pulse on input S. When a pulse is applied to input R, the logical value of the output signals is switched. The system also contains a number of AND gates and OR gates. An AND gate, e.g. gate 22, gives a logical 1 signal at the output only if all inputs are supplied with logical 1 signals. An OR gate, e.g. the gate 50, gives a logical 1 signal at the output if one or more of the inputs is supplied with a logical 1 signal. The ports can be equipped with inverter^ inputs or outputs, which is marked with a small circle. Inversion causes a logic 1 signal to change to a logic 0 signal or vice versa. All electronic circuits in the system are supplied with supply voltage from a voltage source such as e.g. can be an accumulator, in the case of a self-retaining relay 25. The voltage source and the relay are assumed here to be assembled into a unit. The system comprises two contact members 34 and 35 which close momentarily. Wires 70 and 71 are connected with a logic 1 level voltage. Also included are two indicators that emit a light and/or sound signal. These are shown as lamps 41 and 42.

The method according to the invention is carried out in the following way. The beam source 101 is inserted so that the reference surface 102 becomes parallel to the bottom surface 103. The distance H + K between the reference surface and the attachment point 99 is measured with the mast 112 and the arm 113 and recorded in the calculator 14. To this is added the borehole depth component D cos v. When the calculator 14 indicates that the bottom surface 103 is reached, a signal is received at the output 44. This signal closes the percussion mechanism of the drilling machine 107 via the rocker 18, the gate 68, whose output 40 is connected to the valve's 47 input

49, and the valve 47.

In the following functional description of the device according to fig. 3, the designation high means a voltage with a logical 1 level and low a voltage with a logical 0 level. The starting position for this description is that the voltage supply has been interrupted and that the mast 112 and the arm 113 are not in any of their limit positions. When the contact member 34 is depressed, voltage is supplied from the wire 70 to the self-retaining relay 25, whereby all circuits are supplied with supply voltage, and to the input S of the flip-flop 20. Thereby its output 1 becomes high, whereby the output 0 of the flip-flop 16 becomes high and the outputs of the gates 61 and 52 barn. As the arm 113 is not in its upper limit position 114, the output of the indicator 31 is low. Both inputs of gate 63 are thus low and its output 37 is high. This output is connected to the motor of the arm 113 so that the arm is thereby moved back towards the limit position 114. As the photodetector 116 is not in its lower limit position 114, the output of the indicator 32 is low. As the output of the indicator 31 is low, the output of the gate 66 is low and thus both inputs of the gate 65 are low. As the gate 61 output is low, both gate 64 inputs are low. This means that the gate 64's output 39 is high. This output is connected to the operation of the mast 112 in such a way that it is fed back towards the limit position 114. When the arm 113 reaches its upper limit position 114, the output of the indicator 31 becomes high, whereby the output 37 of the gate 63 becomes low and the operation of the arm 113 is interrupted; when the mast 112 reaches its limit position 114, the output of the indicator 32 becomes high, whereby the output 39 of the gate 64 becomes low and the operation of the mast 112 is interrupted. As the outputs of the indicators 31 and 32 are both high, the output of the gate 51 is high, which is why the counter 7 is reset and the output 1 of the flip-flop 20 becomes low.

When the contact member 35 is now pressed in, voltage is supplied from the line 71 to the monostable flip-flop 28, whereby this emits a logic 1 pulse. This restores the calculator 14 above the pull magnet 80, so that its preset function shows the preset value corresponding to the distance A between the reference surface 102 and the bottom surface 103. The pulse also resets the calculators 8 and 9, makes the output 0 of the flip-flop 18 high and its output 1 low, makes the flip-flop 17 output 0 high and its output 1 low, makes flip-flop 16's output 0 low, makes flip-flop 15's output 1 low, and across gate 50 makes flip-flop 27's output 1 low. If the calculator's 14 preset shows zero when the pulse is emitted from the monostable flip-flop 28, the output 44 is high and the gate 67 therefore lets the pulse through to the calculator 12 which is used to record the number of drill holes. As the flip-flops' 18 and 27 outputs 1 are low, both gate 68 inputs are low and its output 40 is thus low. This output is connected to the valve 47's input 49.

The drilling machine 10 7 starts and drilling can begin. As the arm 113 has no ground contact, the output of the indicator 19 is low and as the output 0 of the flip-flop 16 is low, both inputs of the gate 59 are low and thus its output 36 is high. This output is thus connected to the arm's 13 drive motor so that the arm is driven towards the ground. As the photodetector 115 does not sense the radiation source 101, the output of the indicator 30 is low. Since also the flip-flop 27 output 1 is low,

both the gate's 57 inputs are low and thus its output is low.

Furthermore, since the flip-flop 16's output 0 is low, both of the <p>ort's 60 inputs are low and thus its output 3 8 is high. This output is thus connected to the operation of the mast 112 so that the mast is thereby driven upwards. When the mast 112 is driven upwards and the arm 113 downwards, the sensors 91 and 2 deliver pulsex at output UP. These pulses are summed by the summing circuit 4 which sends them to input UP on the calculator 7. When the arm 113 reaches the ground, the output of the indicator goes high, whereby the operation of the arm is stopped via the gate 59. When the photodetector 116 comes into contact with the reference plane 102, the output of the indicator 30 goes high , whereby the operation of the mast 112 is interrupted via gates 57 and 60. As the outputs of the indicators 19 and 30 are both high, the gate's

22 output high, whereby the flip-flop's 15 output 1 becomes high. This means that the monostable flip-flop 29 emits a logical 0 pulse to the input LOAD of the calculator 9, whereby the value stored in the calculator 7 is transferred to the calculator 9. Since the flip-flop 15 output 1 and the flip-flop 17 output 0 are both high, < p>pulses from the <p>pulse generator 24 pass the gate 23. These pulses are partly supplied to input DOWN

on the calculator 9 and partly via the summation circuit 6 the gate 56. As the vi<p>pen's 18 output 0 is high, the pulses pass the gate 56 and are registered in the calculator 14. During the drilling work, the drill support's 110 pliers do not grip the drill rod 108, which is why the indicator's 23 output is low . When the drilling machine 107 is fed forward along the feed beam 106,

the transmitter emits 3 pulses on output DOWN. These pulses pass gate 53, as the output of indicator 33 is low. Since the output 0 of the flip-flop 10 is low and its output 1 is high, the pulses cannot reach the calculator 8, but are supplied via port 55 partly to the calculator 13 and partly to the multiplier circuit 11. In the calculator 13, the total drill length is recorded. In the multiplier circuit 11, the incoming number of pulses from the encoder 3 is multiplied by cos v and the thus modified pulse number is fed via the summing circuit 6 and gate 56 to the calculator 14. The pulses from the generator 24 reduce the value stored in the calculator 9 until it becomes zero. When this occurs, the calculator 9 delivers a pulse at the output BORROW. This pulse is supplied to the input S of the flip-flop 17, whereby its output 1 becomes high and its output 0 low; when the flip-flop 17's output 0 is low, the pulses from the pulse generator 24 cannot pass the gate 23. As the flip-flop 17's output 1 is high, the outputs of the gates 61 and 62 are low. Also, the indicator 31 output is low, which is why the gate 63 output 37 is high. This causes the arm 113 to be driven towards its upper limit position 114. As the output of the indicator 31 is low, the output of the gate 66 is low, and also as the output of the indicator 32 is low, the output of the gate 65 is low. This means that both of the gate's 64 inputs are low and thus that its output 39

is high. This means that the mast 112 is driven towards its lower limit position 114, and when the arm 113 reaches the limit position 114, the output of the indicator 31 becomes high. This means that the output 37 of the gate 6 3 becomes low, whereby the operation of the arm is interrupted. Since the output 1 of the rocker 17 is high, it also means that the output of the gate 66 becomes high, whereby the output 39 of the gate 64 becomes low and the operation of the mast is interrupted. If the current regulator 90 is open, the mast is instead fed back to its lower limit position 114 when the rocker 14's output 1 is high. In order to reach the predetermined bottom surface 103, an extension of the drill rod 108 may be necessary. When the drilling machine 107 is in its forward position on the feed beam 106, the pliers of the drill support 110 are clamped together, whereby the drill rod 108 is held firmly. In addition, the output of the indicator 30 becomes high, whereby the gates 52 and 53 are blocked and no pulse from the transmitter 3 can pass. The drilling machine 107 is disconnected from the drill rod 108 and brought back to its rear position on the beam 106. A further rod section is connected to the drill rod 108, after which the drilling machine 107 is connected to

the thus extended drill rod. When the drill support's 110 tongs are moved, the output of the indicator 33 becomes low and the drilling work can continue as described above.

When the bottom surface 103 is reached, the value in the calculator's 114 pre-registration unit becomes zero and the output 44 thus becomes high. Thereby, the flip-flop's 18 output 1 becomes high and its output 0 becomes low. The output 4 0 of the gate 68 thus becomes high, whereby the percussion mechanism of the drilling machine 10 7 is closed, as described above. The lamp 41 lights up and indicates that the hole has been drilled.

During drilling work, it may be necessary to ground the drilling machine 107, e.g. if the drill rod 108 shows tendencies to get stuck in the borehole. When the drilling machine is backed up, the encoder delivers 3 pulses on output UP. These are passed over gate 52 to the calculator's 8 input UP and the flipper's 10 input R. The first pulse means that the flipper's 10 output 1 becomes low and its output 0 high. Port 55 is blocked. When the drilling machine 107 is again fed forward, the encoder delivers 3 <p>pulses on output DOWN. As vip<p>'s 10 output is high, the pulses pass gates 53 and 54 to the calculator's 8 input DOWN. When the value in the calculator 8 again becomes zero, a pulse is received at the output BORROW which causes the output 1 of the flip-flop 10 to become high and its output 0 low. Hereby, gate 54 is closed at the same time as gate 55 is opened. The pulses from the encoder 3 are now fed to the calculator 14 as described above.

If the photodetector 116 is already above the reference surface 102 when the contact member 35 is pressed in or if

the photodetector during the upward movement for one reason or another does not make contact with the reference surface 102, the mast is fed up to its upper limit position. When the mast comes into this position, the output of the indicator 21 becomes high, whereby also the output 1 of the rocker 27 becomes high and the output 38 of the gate 60 becomes low and the upward movement of the mast 112 is stopped. In addition, the output 40 of the gate 69 becomes high, whereby the percussion of the drilling machine 107 is stopped and the lamp 4 2 is lit. Also, the gate 61 output goes low. Since the indicators' 31 and 32 outputs are both low, the gate's 65 output is low. This means that both of the gate's 54 inputs are low and its output 39 is thus high. This causes the mast 112 to be fed downwards. When the photodetector 116 during the downward movement of the mast makes contact with the reference plane 102, the output of the indicator 30 becomes high,

and since the arm 113 is already in contact with the ground, the output of the indicator 19 is high. The gate's 22 output thus becomes high, whereby vip-

pin 15 output 1 goes high. In addition, the rocker switch 27 is output 1

low, whereby the output 40 of the gate 68 becomes low and the lamp 42 is extinguished. The drilling machine's 107 percussion starts again. When both flippers' 17

and 2 7 outputs are low, the gate's 58 output is low. In addition, the output 1 of the flip-flop 20 is low, so that the output of the gate 61 is high.

This means that port 64's output 39 is low and mast's 112

movement is stopped. The system's operation after this is similar to that previously described.

In the embodiment according to fig. 4 a control system is used

which differs from that in fig. 3 showed, mainly because the UP/DOWN counters are omitted.

For sensing the reference plane 102, as

by the system according to fig. 3 a photodetector 116, amplifier and filter 140 and a trigger 141, which e.g. can be constituted by a Schmitt trigger. These three units together correspond to the indicator

30 in fig. 3. The sensors 134, 135 and 136 which are connected to the

the motor 109, the arm's 113 motor or the mast's 112 motor, is here an embodiment of a simpler embodiment than corresponding sensors in the example according to fig. 3. They cannot sense the direction of rotation of the motors in question. In addition, the monostable rockers 137, 138 and 139 are shown here as separate units. By. the system according to fig. 4, three indicators are used, e.g. pressure sensors 131,

132 and 133 which replace the indicator-equipped pliers 33 on

fig. 3. These indicators indicate that the percussion is working, that the

the rod 108 rotates or that the feeding power is exerted. When drilling, the outputs of these indicators are thus high.

When the switch 130 is moved to position 127, is supplied

the gate 148 voltage from the line 71, whereby the output 1 of the flip-flop 143 becomes high. The mast 112 and the arm 113 are guided via the outputs 37 and 39

back to the limit position 114. When this has taken place, the indicators' 31 and 32 outputs are high. When the switch 130 is moved to the one in fig. position shown in 4, the monostable rocker 28 emits

a logic 1 pulse on output 1, which pulse via the pull magnet 80 the calculator 14 returns, but if its preset

work previously showed zero, the pulse passes port 67 to the calculation

the work 12. Because of the pulse, the output of the flip-flop 18 also becomes 1

low, flip-flop 14 2 output high and its output 0 low and flip-flop 143 output 1 low. Since the mast 112 is not in its upper position, the output of the indicator 21 is low. Both port 68 inputs are thus low, which is why the valve 47 opens the supply of pressurized fluid to the drilling machine's 107 percussion mechanism. As the output 36 is high, the arm 113 is driven towards the ground. Since the photodetector 116 does not have contact with the reference plane 102, the output of the trigger member 141 is low. Output 38 is high and the mast is fed upwards. The movements of the mast 112 and the arm 113 are registered via the encoders 136 and 135, the monostable rockers 139 and 138, the gates 149 and 150, the summing circuit 4, the gate 152 and the summing circuit 6 in the calculator 14. The forward feed of the drilling machine 107 along the feed beam 106 is registered during drilling via the encoder 134, the monostable flip-flop 137 and, since the outputs of the indicators 131, 132 and 133 are high, the gate 151 of the calculator 13. These pulses are also supplied to the multiplier 11, where their number is modified with respect to the value cos v obtained from the encoder 26. Those from the multiplier 11 outgoing pulses are fed via the summing circuit 6 to the calculator 14. When the arm 113 reaches the ground, the output of the indicator 19 becomes high and the gate 150 blocks signals from the encoder 135. In this case, it is assumed that the motor of the arm 113 is equipped with a mechanical disconnection device that interrupts the operation of the arm when it hits the ground. When the photodetector 116 makes contact with the reference plane 102, the output of the trigger member 141 becomes high, whereby the output 1 of the flip-flop 14 2 becomes low and its output 0 high and the output 1 of the flip-flop high. This means that the mast and arm are brought back to the limit position 114. Thus, the gate 152 is blocked. When the calculator's 14 preset value becomes zero, the output 44 becomes high, whereby the rocker 18's output 1 becomes high, the gate 68's output 40 becomes high, whereby the drilling machine's 107 percussion is stopped by the valve 47. In addition, the lamp 41 is lit, which marks that the hole is pre-drilled. As the feeding of the drilling machine 107 along the feed beam 106 is only registered when the outputs of the indicators 131, 132 and 133 are high, the drill rod 108 can also be extended by its design.

In the embodiment according to fig. 5, the mast 122 is mounted on the feed beam 106. This system includes a circuit 144 whose task is to produce a number of pulses corresponding to the distance K in fig. 2. This circuit replaces the arm 113 of fig. 3 and 4. In fig. 5, the multiplier 11 is moved so that the total number of pulses from the sensors 134 and 136 is multiplied by cos v in accordance with that from fig. 2 obtained connection A = (H + K + D) cos v and port 153 replaces ports 149 and 152 in fig. 4. Otherwise, the system works according to fig. 5 in basically the same way as according to fig. 4, why a detailed description of its effect should not be necessary.

Claims (9)

1. Procedure for rock and/or soil drilling of a number of boreholes to an imaginary, predetermined and preferably flat bottom surface (103), characterized in that a reference surface (102) defined by electromagnetic radiation is produced parallel to the said bottom surface (103), that the distance is measured in a direction common to all holes between the reference surface (102) and the point (99) at which the drilling begins, that the borehole depth (D) component in said direction is added to the thus measured distance and that the drilling is stopped when the sum indicates that the bottom surface (103) has been reached. 2. Device for carrying out the method according to claim 1 by rock and/or soil drilling of one or more boreholes to an imaginary and preferably flat bottom surface (103), comprising a drilling machine (107) driven along a feed device for drilling holes to the bottom surface (103), and a recording device connected to the feeding device for recording the forward feed of the drilling machine along the feeding device, characterized by a device (101) for producing a reference surface (102) defined by electromagnetic radiation parallel to said bottom surface (103) and connected to the recording device devices (14) for recording the sum of the distance in a given direction between the reference surface (102) and the point (99) at which the drilling begins and the borehole depth (D) component in the said direction. 3. Device according to claim 2, characterized in that the recording device is designed to record feedback from the drilling machine (107), whereby the position of the front end of a drill connected to the drilling machine (107) rod (108) is always indicated. 4. Device according to claim 2 or 3, characterized in that the registration device comprises means (33), by means of which registration of the drilling machine's (107) feed can be disconnected by splicing the drill rod (108). 5. Device according to one of claims 2-4, characterized in that the recording device includes means (83) for presetting a value that is proportional to the distance between the reference surface (102) and the bottom surface (103), as well as a device for emitting a signal when the bore has reached down to the depth in relation to the reference surface (102), which corresponds to the preset value. 6. Device according to claim 5, characterized by a power supply interrupter (47) assigned to the drilling machine (107) which is designed to interrupt the power supply as a result of the said signal being emitted by the recording device. 7. Device according to one of claims 2-6, characterized in that the device (101) for generating the reference surface (102) comprises a laser. 8. Device according to claim 7, characterized by a device (112, 112) for measuring the distance in a given direction between the reference surface (102) and the point (99) at which drilling begins, comprising a drivable mast (112) which is provided with a photosensitive element (116) for sensing the reference surface (102). 9. Device according to claim 8, characterized in that the mast (112) is a telescopic mast.