SE524375C2 - Method for operating a hammer in a horizontal directional drill - Google Patents

Abstract

A drill head for an apparatus for horizontal directional drilling. The drill head includes a device for detecting angular orientation, a holder for the device for detecting angular orientation, the device for detecting angular orientation being disposed therein, a hammer driven by a liquid and a drill bit. The holder, the hammer and the drill bit are connected head to tail along a longitudinal axis of a drill string with the holder at a proximate end of the drill head and the drill bit at a distal end of the drill head.

Description

30 h.) U1 524 375 2 a series of drill rods which are joined end to end to provide a drill line. The drill line is pushed or pulled through the soil by means of a powerful hydraulic device, such as a hydraulic cylinder. See U.S. 4,945,999 and 5,070,848 and U.S. 4,697,775 (RE 33,793). pressed and rotated simultaneously, 633 AND US-5,242,026. which is designed for drilling is placed at the end of the drill. assist in drilling.

In a variation of the traditional drilling system, a series of drill line rods is used in combination with a percussion tool mounted at the end of the row of rods.

The rods can provide a constant pressure force for the stroke and the inside of the rods can be used to supply the pneumatic drill with compressed air. See US-4,694,913. However, this system has limited commercial application, perhaps due to the fact that the drill string tends to break when used to press if the borehole is significantly larger than the diameter of the drill string.

Precise directional drilling necessarily requires information regarding the orientation and depth of a cutting or drilling tool, which almost inevitably requires that a sensor and transmitter device ("probe") be attached to the cutting tool to prevent misalignment and re-drilling.

Such a device is described in US-5 633 589, the disclosure of which is hereby incorporated in its entirety. US-4,867,255 discloses a directional drilling tool which can be controlled using a pneumatic percussion tool.

Directional drilling tools with rock drilling capability are described in US-5 778 991 and in EP-A2-857 852 and EP-A2-857 853. Although directional drilling tools for both rock drilling and soil penetration are known, no prior art device has provided these properties in a single machine together with the ability to control the tool in both soil and rock. The present invention relates to this need. There is also a need in the art for a directional drilling tool for rock drilling and soil penetration which provides a percussion hammer driven by liquids, provides indexing of an angle rotation detecting device (e.g. a probe) and provides a method for ON / OFF control of the hammer (eg pneumatic or fluid driven). There is also a need for an apparatus that provides improved control capability for the drill bit.

Summary of the Invention A drill head for an apparatus used for directional drilling according to the invention includes a holder (or housing) for a device for detecting angular orientation, such as a probe, a pneumatic hammer and a rotatable drill bit assembly connected with the front end to rear end with the angular orientation housing at one end and the drill bit at the other. The drill head may also include a starting rod, which may be connected to the housing of the angle orientation detector. The drill bit preferably has a forwardly facing primary cutting surface with a plurality of notches located thereon and a peripheral protrusion offset radially outwardly from the primary cutting surface and has at least one forwardly facing peripheral cutting tooth thereon which is suitable for cutting at an angle defined by less than a full rotation of the drill bit. The device for detecting the angular orientation is in a predetermined line direction with the peripheral protrusion so that it determines the orientation of the peripheral protrusion relative to the axis of rotation of the drill head. In a preferred embodiment, the primary cutting surface is substantially planar and circular and has a series of fluid ejector openings thereon, and the drill head has channels for guiding a drilling fluid therethrough to the ejector openings. In another preferred embodiment, the drill bit has a heel portion on an outer side surface thereof at a position opposite the peripheral protrusion, which heel is angled inwardly from the back to the front. Such a drill head can be used in a directional drilling method according to the invention by using a directional drilling machine, which can push and rotate a drill line with the drill head mounted thereon. One such method involves the steps of drilling straight through a medium by pressing and rotating the drill head with the drill line while dispensing strokes on the drill bit with the hammer before changing the drilling direction, determining the angular orientation of the peripheral protrusion using the angular orientation detecting device and changing the direction. during drilling by pressing and rotating the drill bit repeatedly over an angle defined as less than a full rotation of the drill bit while dealt blows on the drill bit with the hammer, so that the drill head deviates in the direction of the cutting action of the peripheral protrusion. The medium can be soil and / or solid bedrock and at different times during drilling. The steps of drilling straight and changing direction can especially be performed in both soil and rock during the same drilling sequence using the same drill bit.

In accordance with a further aspect of the invention, a method of directional drilling is provided in varying conditions including both soil and solid bedrock. One such method involves the steps of drilling straight into both soil and rock by pressing and rotating the drill head with the drill line while striking the drill bit with the hammer, before changing the drilling direction in both soil and rock, determining the angular orientation of the peripheral protrusion. using the angular orientation detecting device, change direction during drilling in the rock by repeatedly pushing and rotating the drill bit over an angle defined by less than a full rotation of the drill bit while dispensing strokes on the drill bit with the hammer, so that the drill head deviates in the direction of the cutting action of the peripheral protrusion and changes direction during drilling in soil by pressing the drill bit with the drill line without rotating it so that the drill head deviates in the direction of the peripheral protrusion and away nova ....- 10 15 20 25 30 35 524 375 gu c .nunn- u 5 from the heel part. Since the primary cutting surface of the drill bit is large and flat, the compressive force of the drill line alone may be insufficient to steer the tool in soft soil without rotation. It is thus preferable to strike the drill bit with the hammer while changing the direction of the soil. This method according to the invention can provide better control under certain ground conditions.

Another aspect of the invention provides a drilling head for a horizontal directional drilling apparatus comprising: a device for detecting angular orientation; a holder for the device for detecting the angle orientation, the device for detecting the angle orientation being located therein; a hammer driven by a liquid, the hammer being arranged and formed to produce impact shocks; and a rotating drill bit assembly connected to the hammer, the rotating drill bit assembly being arranged and configured to receive the impact shocks and the rotating drill bit assembly being oriented by using the angular orientation detecting device to control the drill head. Yet another aspect of the invention provides an apparatus for use in horizontal directional drilling in compressible soil, which is of the type having a drill string connected to a directional drill at a proximal end and a drill head connected to the drill string at a distal end of drilling line, comprising: a drill bit mainly adapted and designed for drilling through rock; a device for determining the angular orientation of the drill bit and for providing a generated signal corresponding to the orientation; and an offset coupling member attached at a first end to the drill string and at a second end to the drill bit, the member being offset from the longitudinal axis of the drill string, the offset portion being oriented in response to the generated signals for guiding the drill bit. Yet another aspect of the invention provides a method of drilling a heel through rock using a horizontal drilling apparatus and guiding a drill head. of the drilling apparatus comprising: pushing the drill head, the drill head being located at a front end of a drill line, through a medium; dispensing strokes on a drill bit located at a distal end of the drill head with a hammer driven by a fluid, the drill bit including an effective guide geometry suitable for guiding the drill head; periodically determining the angular orientation of the drill bit by using a device for detecting the angular orientation placed on the drill head; and guiding the drill head by pressing and rotating the drill bit repeatedly over an angle defined by less than a full rotation of the drill bit while distributing strokes on the drill bit with the hammer, so that the drill head deviates in the direction of the effective guide geometry cutting action. .

Yet another aspect of the invention provides a method of drilling a hole through a medium using a horizontal drill bit and guiding a drill head on the drill set comprising: pressing the drill head located at a front end of the drill line through a medium while delivering blows to a drill bit located at a distal end of the drill head with a hammer driven by a fluid, the drill bit including an effective guide geometry suitable for guiding the drill bit; periodically determining the angular orientation of the drill bit by using a device for detecting the angular orientation placed on the drill head; and guiding the drill head by: if drilling is performed through a compressible soil, changing direction during drilling by pushing the drill line so that the drill head deviates in the direction of a displaced coupling part, which is displaced from a center line to the longitudinal axis of the drill line without dividing blow on the drill bit with the hammer and without rotating the drill nq- 10 15 20 25 30 35 524 375 n / the line; or, if drilling is carried out through rock, strike the drill bit with the hammer, so that the drill head deviates in the direction of the effective guide geometry.

Another aspect of the invention provides a horizontal directional drill with a drill string adapted to drill through rock and compressible soil, the drill having a flushing type aggressive hammer driven by a liquid which uses a method of operating the aggressive hammer. flushing type comprising: determining whether to activate the flushing type aggressive hammer; if drilling takes place in rock and the hammer is to be activated, the following is performed: reduction of the liquid flow for driving the hammer to a first value substantially close to zero; applying a compressive force, which exceeds a predetermined limit value, to the drilling line by means of a drive part of the drilling apparatus and causing the hammer to change from a flushing position; increasing the liquid flow to a predetermined level and continuing drilling in the rock with the hammer activated; if drilling takes place in compressible soil and the hammer is not to be activated, the following is performed: reducing the pressure force on the hammer below a predetermined limit value while keeping the liquid pressure above a predetermined limit value, and through which the hammer switches to a flushing position; and continued drilling in the compressible soil without having the hammer activated. Yet another aspect of the invention provides a horizontal directional drilling apparatus with a drill string adapted for drilling through rock and compressible soil, the drilling apparatus having a standard hammer driven by a liquid, using a standard operation method. the standard type hammer comprising: determining whether to activate the standard type hammer; if drilling in rock takes place and the hammer is to be activated, the following is performed: increasing the liquid flow to a value above a predetermined limit value; or increasing the compressive force provided by a drive member of the horizontal drilling apparatus to a value above a predetermined limit value; and continued drilling in rock with the hammer activated; if drilling in compressible soil takes place and the hammer is not to be activated, the following is performed: limiting the liquid flow to a value less than a predetermined limit value, which is required to activate the hammer; limiting the pressure force to a value less than a predetermined limit value required to activate the hammer; and continue drilling in the compressible soil without having the hammer activated.

Another aspect of the invention provides a system for use in horizontal directional drilling in compressible soil and rock comprising: a horizontal directional drill with a drill string coupled thereto, the directional drill being used to rotate and push the drill string into a medium to be drilled, the directional drill including a drive member adapted to be coupled to a proximal end of the drill string and substantially configured to apply a compressive force to the drill string; a source of pressure to provide a working pressure to be transmitted through a fluid used for drilling; and a control unit for regulating the pressure force provided by the drive part and controlling the working pressure output from the pressure source; wherein the drill line includes, at a distal end: a device for detecting angular orientation; a holder for the angular orientation detecting device, the angular orientation detecting device being located therein; a hammer driven by the liquid; and a drill bit; wherein the holder, hammer and drill bit are connected with the front end to the rear end along a longitudinal axis of the drill line with the holder located at an adjacent end of the drill head and the drill bit located at a distal end of the drill head.

Another aspect of the invention provides a drilling head for a horizontal directional drilling apparatus comprising: a hammer driven by a liquid; u-uu ø. »» ~. o .ua -.- 10 15 20 25 30 35 524 375 9 and a drill bit driven by the hammer, the drill bit having an effective guide geometry.

Another aspect of the invention provides a drilling head for a horizontal directional drilling apparatus comprising: a hammer driven by a liquid, the hammer being arranged and formed to provide impact shocks; and a rotatable drill bit assembly connected to the hammer, the rotatable drill bit assembly being arranged and formed to receive the impact shocks and having an effective guide geometry.

These aspects of the invention are further described in the detailed description which follows.

Brief Description of the Drawings In the accompanying drawings, in which like numerals correspond to like elements,: Fig. 1 shows a side view of a first embodiment of a drill head according to the invention with cemented carbide teeth removed from the drill bit; Fig. 2 is a top view of the embodiment shown in Fig. 1, showing the holder cover of the probe; Fig. 3 is a rear perspective view of the drill bit shown in Fig. 1 with the drill bit shaft removed; Fig. 4 is a front perspective view of the first alternative drill bit according to the invention with cemented carbide teeth in place and mounted on a drill bit shaft; Fig. 5A is a side perspective view of the drill bit and drill bit shaft shown in Fig. 4; Fig. SB is a cross-sectional view taken along line 5B-SB of Fig. 5A; Figs. 6A and 6B are enlarged longitudinal sectional views taken along line 6-6 of Fig. 3, with 6A showing a front portion of the device and 6B a rear one; Figs. 7A and 7B show an enlarged longitudinal sectional view taken along line 7-7 of Fig. 3, 7A showing a front portion of the device and 7B a rear one; Fig. 8 is a top view of a second alternative drill bit and drill bit assembly according to the invention; Fig. 9 is a side perspective view of the drill bit and drill bit assembly of Fig. 8; Fig. 10 is a front view of the drill bit of Fig. 8; Fig. 11 is a side view of the drill bit and drill bit assembly of Fig. 8; Fig. 12 is a top view of a third alternative drill bit and a drill bit assembly according to the invention; Fig. 13 is a side perspective view of the drill bit and drill bit assembly of Fig. 12; Fig. 14 is a front view of the drill bit of Fig. 12; Fig. 15 is a side view of the drill bit and drill bit assembly of Fig. 12; Fig. 16 is a side view of a fourth alternative drill bit according to the invention with the rest of the tool removed, showing the guide function in rock; Fig. 17 is a front view of the drill bit of Fig. 16; Fig. 18 is a front view of a fifth alternative drill bit according to the invention; Fig. 19 is a side view of the drill bit of Fig. 18; Fig. 20 is a perspective view of the drill bit of Fig. 18; Fig. 21 is a partial sectional view of the rear longitudinal portion of an embodiment of a hydraulic rock drilling machine; Fig. 22 is a partial sectional view of the front longitudinal portion of the embodiment of a hydraulic rock drilling machine; Figs. 23A and 23B show fragments of longitudinal portions in the rearward and forward portions of a first embodiment of a rock drill with a hammer placed in a forward position; Fig. 24 is a truncated fragmentary sectional view corresponding to those of Figs. 23A and 23B with the hammer placed in a rearward position; Fig. 25 is a sectional view of an embodiment of a drill bit according to the present invention; Fig. 25A shows an enlarged view of a part of a drill bit according to the present invention; Fig. 25B is a sectional view of a drill bit assembly according to the present invention; Fig. 26A is a sectional view of a holder for a device that detects angular orientation according to the present invention; Fig. 26B shows a perspective view of an indexing assembly portion of a holder for detecting angular orientation according to the present invention; Fig. 26C shows a sectional view of an indexing assembly portion of a holder for detecting angular orientation including an insulator according to the present invention; Fig. 27 shows a system including a directional drill according to the present invention; Fig. 28 is a flow chart showing a method of operating the present invention; and Fig. 29 is a flow chart showing a method of operating the present invention.

Detailed Description of the Invention As the manufacture and use of various embodiments of the present invention are discussed in detail below, it should be understood that the present invention provides many applicable inventive concepts, which may be realized in a large number of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways of making and using the invention and do not limit the scope of the invention. References to a numbered element, which are shown in several alternative forms denoted by A, B, etc., without such a letter are intended to refer to all the alternative forms.

Referring to Figures 1-3, 6A-6B and 7A-B, a drill head 10 according to the invention includes, as general components, a probe holder 14, a pneumatic hammer 1624 and a drill bit assembly 18 which is connected with the front end facing the rear end, as shown. As noted above, the drill head 10 may also include a starter rod 12.

The starter rod 12 connects at its rear end 13 to a conventional drill string driven by a directional drill and compressed air is fed through the drill string, the starter rod 12 and a channel in the probe holder 14 to drive the hammer 16. The drill bit assembly 18 includes a drill bit 19A with a series of cutting teeth 20A and a drill bit shaft 21A, which is used to mount the drill bit 19A on the front end of the hammer 16. The drill bit 19A is releasably mounted to the shaft 21A by means of locking pins inserted through transverse heels 23. Angled openings 22A are arranged in the head 18 for discharging compressed air from the hammer 16 out of the front part of the drill bit 19A. The compressed air has been combined with a foam-forming agent so that a lubricating drilling foam is formed spontaneously during ejection / decompression from the drill bit 19A. This foam is used to transport soil and / or small rock pieces away from the path of the drill bit.

The starting rod 12, the probe holder 14 and the pneumatic hammer 16 may be of types already known in the art. The hammer 16 can, for example, be an Ingersoll-Rand hammer of the down-heel type instead of the one shown. A spline coupling of the type provided by Earth Tool Corporation of Wisconsin under the model designation Spline-Lock can be used to connect the probe holder 14 at either end to the hammer 16 and the Start Rod 12. The same type of locking pin connection, excluding splines, is used to mount the drill bit 19A against the shaft 21A, as described above.

Figures 6A-6B and 7A-7B show the drill head 10 just before start-up. Compressed fluid from the drill line flows along a central channel 32 in the starting rod 12 and is in turn moved into a longitudinal channel 34 in the probe holder 14, which channel 34 is separated from the probe space 36. The probe (not shown) is mounted in accordance with conventional practice. 5 25 37 524 375 1: ice in a predetermined orientation relative to the drill bit, for example by fitting one of the ends of the probe towards a smaller projection 38. Shock absorbers can be arranged at opposite ends of the probe space to insulate the probe from vibrations and shocks.

The pressurized fluid then passes out of the front end of the channel 34 to a rear opening 40 in a valve rod 42 which forms part of the hammer 16. A rear annular flange 44 of the valve rod 42 is held in place between an inwardly extending annular flange 46 in a tubular housing 48 of the hammer 16 and a front end surface of the probe housing 14. Pressurized fluid flows from the opening 40 into a manifold 50 with several radial openings 52 and then into an annular rear pressure chamber 54 formed between a front portion 56 of smaller diameter of the rod 42 and a rear tubular portion 58 of an impact bolt 60. The pressure in this chamber acts on the impact bolt 60 in the forward direction toward the position shown, a front end of the impact bolt 60 dispensing an impact against a rear abutment surface 62 of the drill bit shaft 21A. .

Radial openings 66 provided by rear tubular members 58 allow pressurized fluid to flow into an annular channel 68 with an outward opening on the outside of the rear portion 58. As shown in Fig. 6A, channel 68 communicates with a radially inwardly extending opening 70 in the impact bolt 60 by means of a longitudinal groove 71. At this point, however, the fluid flow is blocked because the opening 70 is covered by a front surface 74 in the reduced diameter portion 56 when the impact bolt 60 is in the position shown.

The drill bit shaft 21A is substantially cylindrical but has a series of evenly distributed radial splines 72A along its center portion which are elongate in the longitudinal direction of the shaft 21A. Splines 72 fit snugly together and are slidably mounted in corresponding grooves 74 formed on the inside of a sleeve 76. The sleeve 76 is detachably mounted in the front end of the tubular housing 48, e.g. 10 15 20 25 30 35 524 375 -w .Lay using threads 78, and have a front end cap 80 that is firmly attached with bolts 81 against it. Spline 72 preferably includes a larger width main spline (see, e.g., 75B in Fig. SB), which fits into a corresponding main channel in the sleeve 76. The main spline 75 ensures that the drill bit 19 is aligned correctly with the probe for the guide. Measures should also be taken to ensure that the main channel in the sleeve 76 is in the correct position. For this purpose, for example, the holes 79 for the bolts 81 for mounting the sleeve 76 against the front end cover 80 can be arranged so that the bolts 81 can only be inserted when the holes 79 are in the correct position relative to the cover 80. The cover 80 has in turn, a series of splines 81 which engage grooves 83 at the front of the hammer housing and may, if desired, also include a main spline and channel combination to ensure proper alignment. The same groove 83, if made deeper in the radial direction, can also be used to engage the corresponding splines on the sleeve 76 as an alternative means of fitting the sleeve 76 in the correct position.

For the purposes of the present invention, a main spline and a main groove may be either larger or smaller than other splines, as long as it provides a desired wedge function. The spline connection 85 which connects the hammer 16 to the probe housing 14 has a main spline and a main groove. In this way, the row of wedge joints guarantees that the drill bit 19, especially the peripheral protrusion described below, will be correctly oriented relative to the probe.

As the drill string exerts pressure on the drill head 10 in the forward direction, such pressure overcomes the pressurized fluid and begins to move the drill bit 19A backward, reducing the distance between the drill bit 19A and the front end cap 80. This in turn forces the drill bit shaft 21A and the impact bolt 60 to move. in pairs backwards. When this occurs, the opening 70 moves backwards and is uncovered when it reaches an outwardly open annular channel 82 in the reduced diameter 56 565 lb front portion 56 of the rod 42. At this time, compressed fluid flows through the channel 82 in the outward direction through a second radial opening 84, similar to the opening 70 but offset rearwardly therefrom, through a longitudinal elongate groove 86 on the outside of the impact bolt 60 to a front pressure chamber 88. At this time, the impact bolt 60 begins to move backward due to the pressure in the chamber 88 and a gap is opened between the impact bolt 60 and the rear abutment surface 62 of the drill bit shaft 21A. However, with a stepped plastic tube 89 mounted in the rear end of the drill bit shaft 21A and in a front end of a through hole 91 in the impact bolt 60, the compressed fluid is temporarily prevented from entering a central through hole 90 in the drill bit shaft 21A.

As the impact bolt 60 continues its rearward stroke, the rear opening 84 is covered by the front portion 56 of the rod 42 and the impact bolt 60 releases the rear end of the plastic sleeve 89 and allows decompression of the front chamber 88 through the outlet openings 22A. Pressurized fluid is sprayed out through the hole on the drill bit and converted to foam. At this time, the force in the rear pressure chamber 54 becomes greater and the impact bolt slows down and changes direction to begin its forward stroke. A chamber 92 at the rear of the striking bolt 60 is preferably emptied by means of small channels 93 in the spline connection 94 to prevent unnecessary pressure from building up in the chamber 92. In this way the hammer 16 is driven continuously and starts automatically when a predetermined thrust limit value is applied through the drill line.

The drill bit 19A has a radial extension or peripheral protrusion 96A which carries several peripheral inserts 97A, which substantially correspond to the other cemented carbide teeth or pins 20A. This is more clearly shown in Figs. 4, 5A and 5B, the drill bit 19B being similar to the drill bit 19A, and the drill bit shaft 21B being comparable to the shaft 21A except that splines 72B are divided into front and rear sections, as shown .

There are preferably at least three peripheral inserts 97, for example one at the center of the protrusion 96 and two others equidistant therefrom, which define an arc, substantially describing an imaginary circle larger than the outer circumference of the drill bit 19. Also a single insert 97 may, however, prove sufficient for certain purposes and thus the peripheral protrusion 96 need not be wider than a single such insert 97. However, it is preferred that the peripheral protrusion 96 define an angle A from about 45 ° to 90 ° relative to the longitudinal the axis of the drill bit 10 (see Fig. 18) or has a length of from about% to% of the width of the drill bit 19.

Peripheral inserts 97, as well as teeth 20, tungsten carbide pin. is most preferred The periphery is a term that defines the diameter of the hole provided by the drill bit 19. That periphery is the size drawn by the heel portion 98 on the opposite side of the drill bit 19 as seen from the peripheral protrusion and one or more peripheral inserts 97 if the drill bit is rotated one full turn. The heel area 98 acts as a bearing surface which provides a reaction force for this peripheral cutting action. A primary cutting surface 99 having the pins 20 removes material from the center area of the hole in the same manner as a classic non-steerable rock drill bit does. 4-5B and 8-20 show several variants and 19D, 19E, Figs. Configurations of drill bits 19C, 19F which can be used in the present invention. As discussed below, the heel 98 may be a surface (98C) with a relatively large slope or have a very small taper seen from the rear toward the front (see 98F), depending on Similarly, the peripheral protrusion 96 may protrude a substantial distance (96E). 96F) or only slightly (96C), or not at all if the drill bit 19 has a suitable asymmetrical shape. In Figs. 12-15, an angled recess 101 is provided for the manner in which the tool is to be operated. 10 15 20 25 30 35 524 375 17 16-20 further includes each ejector opening 22 a shallow, skin-away transport of soil and cutting material. In FIG. Each of these embodiments has been found to be successful in drilling, although drill bits 19E and 19F have been found to be most effective for conditions involving steering in both soil and rock.

The present invention enables a pipe or cable to be placed below ground level in fixed rock conditions at a desired depth and along a path which may bend or change direction.

The procedure described allows the operator to start at the surface or in a small excavated cavity, quickly drill through the rock using the pneumatically or fluid-driven impact hammer 16, and make gentle changes of direction in any plane. The operator can thus maintain a desired depth, follow a swinging facility in the right direction or maneuver between other existing, buried facilities that can cross the desired path.

One invention specifically relates to the interaction between the shape of the drill bit during the impact cutting process and the movement of the drill line, which connects the directional drill with the hammer. The movement in relation to the properties of the drill bit is important. The drill bit 19F shown in Figs. 18-20 does not depend on the guide plane, the slope or the angle to effect a change of direction. The change of direction is effected by means of the non-symmetrical shape of the drill heel which is effected when the drill bit 19F is subjected to impact and rotated at a constant angular velocity with an unchanging angle of rotation and in a cyclic manner around the drill line, the angle being less than one whole. rotation.

The rotational speed must be approximately constant for 97F, so that the angle of rotation must enable the carbide impact inserts 2OF to penetrate the entire borehole front. 10 15 20 25 30 35 524 375 §g¶å = lö be less than an entire rotation so that the drill heel is not symmetrical. The angle passed transversely must be constant for several cycles as the penetration per cycle will be limited, perhaps 0.05 to 0.25 per cycle depending on rock conditions and rotational speed. The angle must be greater than zero, otherwise no cutting takes place, it is usually greater than 45 ° up to 240 ° with the range 180 ° to 240 ° giving the best results. The center point of the angle sweep must be kept unchanged to give a change of direction.

The borehole provided will be asymmetrical because the shape of the drill bit is asymmetrical. After drilling a certain distance with execution of the described and it is not rotated completely around the axis of the drill line. the measures and over a number of cycles the asymmetrical drill heel will cause a gradual change of direction (see for example Fig. 16). The borehole is larger than the drill head 10 or the drill string and allows the drill bit shaft and also the drill bit to be inclined angularly relative to the drill shaft. A distance between the drill head and the borehole wall allows the drill head 10 to be tipped or repositioned in the borehole by induced drilling forces. The presence of the drill protrusion 96 causes the pressure center on the front surface of the drill bit to move from the center axis of the drill head (where non-steerable hammers have it) to some point closer to the peripheral inserts 97. The static pressure and mass act along the drill shaft. The reaction force from the impact cutting operation is considerable with maximum forces easily reaching 50 0000 LB for a period of several milliseconds per stroke.

With the impact reaction force along an axis other than the hammer mass and the pressure, a torque (torque) is induced which will bend the drill head 10 and the drill line within the clearance distance of the drill heel. The drill head will have a tendency to rotate away from the peripheral protrusion.

This action steers the drill head in a new direction and causes the borehole to advance along this axis. The shaft changes continuously, which gives a curved borehole path.

To avoid the creation of a round and symmetrical borehole during the steering operation, the drill bit 19 must not cut during the entire rotation. To make this a cyclic process, the operator can either rotate in the opposite direction when the angular limit has been reached or pull back away from the front surface and continue the rotation around until the starting point is reached. A third alternative is to back away from the front surface and rotate in the opposite direction to the starting point. All three methods have been used successfully, but the third method can cause difficulties if a small angle of rotation is used and the hole has a large asymmetry. In this case, the drill bit can not be rotated and can get stuck.

The predominant feature of all successful drill bits 19 shown is the existence of peripheral inserts 97 mounted on a peripheral protrusion 96. Regardless of whether the drill bit has a shaped angled heel or wedge 98 or not, the peripheral protrusion must be in the drill head 10 to successfully steer in fixed Mountain. The drill head 10 will steer in grainy, loose material, such as soil, without a peripheral protrusion but with a wedge. It will also steer in grainy soil without a wedge but with a peripheral protrusion. It rules first in soil with both properties.

The placement of the mass in the hammer / probe housing assembly is important. It would be detrimental to place the center of mass in the direction of the peripheral protrusion side of the hammer shaft. It is acceptable to place it in the center. It is advantageous to place it from the peripheral protrusion. The reaction from the non-centered mass will increase the desired deviation of the hammer and thereby increase the maximum control speed that can be achieved. Since the hammer 16 is substantially symmetrical in its mass distribution, the center of mass of the drill head 10 can be easily changed by displacing the probe housing 14 and as an alternative starting rod- u u; v u u, v v »v u n. 1 1- n» u. | . u »n n n o: na n. .nu 1 u: v vn n v n = v. o u v: n n o ~ 4 f | u n .. 10 15 20 25 30 35 524 575 ¿U a 12 away from the peripheral protrusion to displace the center of mass of the drill head 10 in a preferred direction.

The angle of rotation affects the steering speed. Smaller rotation angles create a more eccentric borehole shape and increase the steering speed. However, small rotation angles also create smaller boreholes compared to large rotation angles and can make it difficult to pull the hammer back out of the borehole.

Usually, more eccentric drill bit designs will steer faster than smaller eccentric designs. The limitation of eccentricity is the challenge that is achieved by transferring the bending moment from the displaceable drill bit shaft to the hammer body.

A more eccentric drill bit has a larger torque and an increased tendency to cause "clutter" on the slide. The existence of this element results in the incorporation of a wide bearing surface on the splines of the drill bit shaft as well as a secondary bearing behind these splines.

The drill head according to the invention is unique in that the operator can make the borehole path deviate at will (or go straight) regardless of the difficulties that solid rock presents compared to compressible material, such as soil. A combination of movements provides either steering or straight drilling. The operating characteristics of the hammer combined with the geometry of the head are used together with varying rotational movements to direct the hammer.

Drilling straight is the easiest direction to achieve. With compressed air supplied through the drill line in the range of 80-350 psi, a compressive force is applied to the hammer. The compressive force acts on the front surface of the hammer and counteracts the pneumatic force that has extended the reciprocating head. The hammer and drill string must move forward and compress the drill head approximately% "to 1" in the direction of the hammer. This change of position of the head relative to the hammer switches the internal valves and starts the impact action of the tool. Usually ap- man v 10 15 20 25 30 35. ..... _. . HRS _ ..... ..... . HRS.

H .... ... "" .... ".. ...... ............. .

To drill straight, the operator rotates the drill continuously around the axis of the drill line. The speed is usually around 5 to 200 RPM. Maximum productivity is a function of the hammer speed, usually from 500 to 1200 beats / min as well as the rotational speed. The ideal speed is that which ensures that the tungsten carbide pins strike sequentially with approximately% of their diameter (normal pin diameter is% ") from the early-off (tangential) stroke. In this example, a borehole with a diameter 6 "which is achieved with a hammer at 700 beats / min is rotated according to the calculations shown: pin diameter = 0.50", X pin diameter = 0.25 ", circumference = 6.0" * n = 18, 84 ", rotation per stroke = 0.25" / l8.84 * 36O degrees = 4.78 degrees, degrees * 700 beats / min. = 3346 degrees / min., 3346/360 = 9.3 RPM When the pin pattern center is eccentric in relation to the center of the drill head, a round hole is machined around the theoretical cutting axis, this axis being placed midway between the outermost peripheral insert and the bottom of (heel).

Drilling an arc of the guide plane (steering) requires a more sophisticated movement than going straight. This explanation assumes an upward steering from a nominal horizontal borehole axis. Any direction can be accessed by reorienting the center of the steering movement. To steer upwards, the peripheral inserts must be oriented at the top and the guide plane or heel must be placed at the bottom. By thinking of the front surfaces as a bell placed on the front surface of the borehole, the operator starts with the peripheral pins at 8 o'clock. Once in operation, the drill line is rotated clockwise at a speed that preferably corresponds to the ideal speed for straight drilling. This rotation continues for 8 hours according to the clock dial until the peripheral pins reach the clock 10 15 20 25 30 35 524 575 ajg n e: r ¿¿an 4. At this point, the hammer is retracted far enough to pull the pins out of the front surface of the borehole, thereby stopping the hammer. The drill line is rotated counterclockwise to 8 o'clock and the process is repeated, or one of the other methods for returning to the starting point described above can be used.

This method, known as "shelving", will cut a shape that is approximately circular but with a strip of rock left at the bottom. This strip is the slope “shelving”). The working procedure is repeated many times, the forward speed per 4-hour clock cycle can be 0.20 ". With a cycle speed of 30 times / min, the forward speed would be 6" / min. The drilling profile with the partially circular front surface continues to cut straight until the guide plane (wife) comes in contact with the slope.

This slope strip forces the profile to be raised while the strip shown in a 6 "borehole has a height of 0.12". angular degrees from the axis, further advancing is made.

The guide plane, at 12, travels over this strip or slope upwards 0.12 "during approximately 0.57" of forward movement. The drill bit again cuts straight with its partially circular profile at a distance of approximately 2.5 "until the guide plane comes into contact with the slope again.

This working procedure is a step operation with tapered elevations and straight steps of the type shown in Fig. 16. The effect of the slope not only changes the elevation of the drill head but also helps to change the slope of the angle. The rear part of the drill line (approximately 30 "towards the back of the front surface) acts as a support point or pivot point. Raising the front of the hammer without raising the rear end causes it to tip up. With sufficient change of direction, the operator can now drill straight after The drill head changes direction by 3 degrees during a displacement of only 32 ", a figure that would be acceptable even in compressible media. 10 15 20 25 30 35 524 375 45 The previous control method is most effective in rock but can also be used in soil or other loose medium.

Ground control can also be achieved by using the technique of stopping the rotation of the drill bit and relying on the heel area on the side of the drill bit to cause deviations in the desired direction. As noted above, it is most effective to continue driving the hammer when steering in this manner.

Since the disturbance caused by the procedure according to the invention is minimal, the cost that arises for the restoration of the workplace is often minimal. A borehole can be created under a motorway divided into several lanes while the road is used even if solid rock is encountered during drilling. No disturbance or traffic control is needed as the equipment can be mounted from the edge of the motorway, no explosives are used, the position of the drill head is constantly tracked during drilling and no heavy equipment needs to pass over to the opposite side of the road. The drill can be started at the surface and can be terminated by coming out of the rock surface at the target point. In addition, if it is necessary to move through sand or soil to reach the rock formation, the drilling head according to the invention allows control under such conditions.

Alternative embodiment In an alternative embodiment, the percussion hammer according to the present invention can be operated with a liquid medium for power transfer to the active part of the drill. The liquid medium may comprise aqueous and non-aqueous fluids (eg drilling fluid solutions, dispersions or sludge) fluid (eg air). used to drive fluid driven hammers may include instead of a compressible such hydraulic working fluids as aqueous and non-aqueous fluids, which may be mixed with additives for a number of useful properties. In drilling or drilling operations which already include a supply of drilling fluid (commonly known as drilling mud) to assist in drilling or drilling operation, it is preferred to use such drilling fluid which transmits the working pressure for drilling. to drive a liquid-powered hammer. However, hydraulically operated fluid fluids can also be used to drive the fluid driven hammer.

Aqueous liquids suitable for driving a liquid hammer include aqueous solutions or dispersions with certain types of materials, such as a synthetic polymeric material or a natural or synthetic clay, which are known to have expansion and lubricating properties, such as a bentonite clay. . Other aqueous fluids that can be used to drive the fluid hammer include aqueous drilling fluids containing CaO, CaCO 3, lime and potassium compounds and similar inorganic materials. Fluids may contain small amounts of polymeric materials including preferred unmodified polymeric additives and sulfur-based polymers such as styrene-maleic anhydride copolymers and at least one water-soluble polymer made from acrylic acid, acrylamide or their derivatives. Other aqueous drilling fluids also include water combined with gelling agents, antifoams and glycerins selected from the group consisting of glycerin, polyglycerin and mixtures thereof.

Others include invert emulsion drilling fluids. Polymer-based fluids can be mixed with organic or carbohydrate-based thickeners including, for example: cellulose mixtures, polyacrylamides, natural galactomannans and various other polysaccharides.

Non-aqueous liquids suitable for driving the liquid hammer 216 include synthetic fluids including polyglycols, synthetic hydrocarbon fluids, organic esters, phosphate esters and silicones.

It should be understood, however, that water-based and non-water-based liquids for operating the liquid-powered hammer are not limited to those mentioned above. Those skilled in the art will recognize that other fluids may be used as drilling fluids and for operating a piston hammer without departing from the scope of the invention.

A hammer-operated impact hammer provides several additional features and advantages over a pneumatic impact hammer. A liquid-powered hammer can, for example, be operated with a working pressure of about 800 to 2000 psi instead of the usual range of 80-350 psi which is mainly used in pneumatic hammers which are operated with compressed air. The ability to operate the liquid-powered hammers at higher working pressures provides higher energy capacity for the impact hammer and therefore provides an increase in the working energy available for drilling.

As noted above, the maximum working pressures conventionally used to drive pneumatic hammers are limited to about 300 to 500 psi. This limitation in the relatively low working pressures of the pneumatic hammers is a result, in part, of the potential safety risk that is imminent when using compressible fluids. Operation with a working pressure of several hundred psi (and higher) entails, for example, the risk of an explosion due to a fall in a pressure line. To overcome these potential safety problems, the pneumatic hammers are therefore usually limited to a maximum working pressure of approximately 300 to 500 psi.

Furthermore, since the energy of a pneumatically driven hammer is proportional to the square of its velocity and the velocity is proportional to the working pressure, the energy available for drilling is proportional to the square of the working pressure. Accordingly, any limitation of the working pressure of the pneumatically driven hammer directly results in a limitation of the available working energy for drilling.

Another feature of the liquid-powered hammer is a relatively high energy transfer efficiency compared to the pneumatically driven hammer. Since the compressibility of liquids is in principle zero and can be disregarded from in most practical applications, for example, the energy loss in a liquid-powered hammer is due to the heat conversion. transformation as a result of the practicability of zero. However, this differs from the pneumatically driven hammers, which lose energy efficiency due to the compressibility of the fluid used to drive the hammers. As an example, when the pneumatic fluid is heated under compression, this heat is later dissipated to the environment and thus reduces the energy efficiency of the pneumatic hammer.

Furthermore, during drilling, the fluid fluid used to operate the fluid driven hammer does not lose pressure because the channels for guiding the fluid to the hammer are kept filled. This is not the case with pneumatic hammers where the pneumatic fluid line is usually subjected to a pressure drop when each new pipe segment is added to a drill line. Therefore, the volume of the pneumatic fluid line must be pressurized again before continuing a drilling operation. It will be appreciated that the need to re-pressurize the line becomes more troublesome as the number of drill rods in the drill line increases. Yet another feature of the liquid-powered hammer is the ability to transport away drill cuttings produced by the drilling operation from the front of the drill string around the drill bit. Use fluid fluid exiting the drill bit through channels provided thereon for such a purpose provides an efficient way to transport the drill cuttings away from the front of the drill head. The air used in pneumatically driven hammers, unlike liquid-powered hammers, does not transport drill cuttings away as efficiently as the liquid used.

It will be appreciated by those skilled in the art that the liquid driven hammer 216 (see Fig. 22) is usually operated in the same manner as discussed above with reference to the pneumatic hammer 16. In addition, each type of hammer has, as discussed above, depending on whether it is pneumatic or liquid driven, clear advantages unique to the medium used to drive the hammer (eg compressive fluids versus liquids). In an embodiment of the invention, the pneumatic hammer 16 can thus be replaced 21 and 22), 25). 400 and 216 can, for example, be driven with a hammer-driven hammer 100, out of a liquid-driven hammer 100 400 23 and 24, (see fig. (See fig. Or 216) (see fig. is usually well known to those skilled in the art without departing from the scope of the invention.

Those skilled in the art will recognize that a liquid-powered hammer of the present invention may be of a type already known in the art. A liquid-powered hammer may, for example, be of the type described by US-5,715,897, US-5,785,995, US-5,107,944 and / or US-5,014,796, which are hereby incorporated by reference in their entirety. However, those skilled in the art will recognize that the hammer (s) described in the foregoing references were not steerable, did not include a probe, and were not used in a horizontal drilling application.

In general, hydraulic hammers, like other fluid hammers, require certain levels of working pressure and flow to activate the hammer. In addition, the fluid-driven hammers require a force (eg, a compressive force generated by a drive member of a horizontal directional drill) against a drill bit acting against a piston of the hammer.

If this force is missing, the hammer will not be activated, regardless of the pressure or flow applied to the hammer.

The design of a liquid-powered hammer can be modified to change the relationship between these parameters (eg compressive force and working pressure). A liquid-driven hammer can thus be designed to allow working pressure to be transmitted through a liquid applied to the hammer if no compressive force against the drill bit is lacking and as a result enable the liquid-driven hammer to be activated in response to a subsequent application of a nominal force to the drill bit. . This design comes in the following. 'ß v _' _: vv: I u.- "uu o. -. ._ x- 'I'. v o.. fa. n. _ _. _ fu. 1...,., _ v enn-n n - nn nu -. _:: u; -.. u.,., f »uu" n - ~ ... n-.n 10 15 20 25 30 35 524 575 28 jande to be referred to as a liquid (NIN) type hammer.

An example of a liquid-powered hammer of standard NIN type is manufactured by G-drill AB in Sweden, which is commercially available under the name "Water Powered ITH Hammer", WASSARA WlOO AND WlOOS. The hydraulic hammer is usually designed to be operated with relatively clean water as the working fluid.It will be appreciated that when drilling fluid is used to drive the hammer, the liquid NIN type liquid hammer may be modified. to design the NIN hammer can, for example, be modified so that the hammer is driven in the right way with the relatively higher viscosity and the relatively higher levels of contaminants that are usually found in drilling fluids.

Figures 21 and 22 show an example of a liquid-driven hammer of standard NIN type, generally designated 100.

A brief summary of the hammer 100 will be presented herein. For a more detailed description of the hammer, however, reference is made to US-5,715,897.

When operating the hydraulic stop motor in the embodiment shown in Figs. 21 and 22, pressurizing the rear drive chamber 126 means that the piston hammer 124 is moved in its forward stroke via pressurization of the piston area 137. Pressure lowering in the rear drive chamber 126 makes that the piston hammer 124 moves in its return stroke. The return stroke is effected by the continuously pressurized front drive chamber 134 which acts on the rod area 136.

The pressurization and depressurization of the rear drive chamber 126 are controlled by the position of the flush valve 140. The flush valve 140 has two operating positions. The first operating position is shown in Fig. 21, and pressurizes the rear drive chamber 126. In the second operating position (not shown), the spool valve 140 is displaced rearwardly towards the rear support 138. This position means that the rear drive chamber 10 524 375 28 126 and the guide surfaces A1 and A2 are subjected to a pressure drop. Depending on the continuously acting pressure on the guide surface A3, the purge valve 140 is kept in the second operating position independently of the pressure drop of the guide surfaces A1 and A2.

The cyclic movement of the spool valve 140 from the first operating position to the second operating position is controlled by the position of the piston hammer 124. When the piston hammer 124 has moved forward to strike the drill bit 114, the guide surface A2 is pressurized to move the spool valve 140 to its position. second operating position and lowers the pressure of the guide surface A2. When the piston hammer 124 has reached the limit of its return stroke, the guide surface A1 is pressurized to move the spool valve 140 to its first operating position.

At start-up, it is assumed that the machine is in an initial depressurized state. Pressurized water enters the machine via a rear support 122 and pressurizes the annular space 158, as described above. A number of parallel channels 157 lead axially through the valve housing 120 and connect the front drive chamber 134 to the space 158. Consequently, the front drive chamber 134 is pressurized substantially immediately at start-up.

Similarly, a plurality of channels connect a series of openings 162 entering the annular chamber 147 with the pressurized space 158 to substantially immediately pressurize the chamber 147 at start-up.

At start-up, it cannot be assumed that the flush valve 140 or the piston hammer 124 are in any particular configuration. Therefore, different configuration states will be analyzed, each assuming that the machine now has a pressurized front drive chamber 134 and a pressurized annular chamber 147, as described in the previous paragraph.

Furthermore, preferably the limiting axial positions of the piston hammer 124 can be defined. Backward movement of the piston hammer 124 can be limited by interfering with the tube 123 and restricting, so that the opening 160 preferably remains in the open position. Backward movement of the piston hammer 124 may alternatively be limited by interference between the valve housing 120 and the surface A5, or backward movement of the piston hammer 124 may be limited by interference between the valve housing 120 and the surface 137, which closes the rear drive chamber 126 and the closing opening 160 completely. Leakage of hydraulic fluid from the opening 160 into the rear drive chamber 126 can then pressurize the piston area 137, if necessary.

Forward movement of the piston hammer 124 can be limited by abutment against the target, i.e. the drill bit 114 (as shown in Fig. 22). With this front limitation, a gap may exist between the surface A6 and the guide bearing 118 and the piston space for the surface A6, which ensures that the piston space of the surface A6 can be pressurized at start-up.

First, assume that the flush valve 140 at start-up is in the forward position shown in Fig. 22.

The annular chamber 147 communicates with the annular chamber 148 and via the opening 162, the channel 159, and the opening 160, the rear drive chamber 126 will be pressurized.

If the piston hammer 124 is at its rear travel stop (not shown), the openings 153 and 155 would be closed. The opening 156 would be open.

The free opening 156 is in communication with the front drive chamber 134 and would pressurize the piston area A1 via the channel 154 and the annular chamber 145 and keep the spool valve 140 in its front position. Pressurizing the rear drive chamber 126 will cause the piston hammer 124 to begin its forward stroke and start the duty cycle.

If the piston hammer 124 is in an intermediate axial position (with the opening 153 closed), the openings 155 and 156 may be open or closed at the start-up. If either the opening 155 or 156 is open then the piston area A1 would be pressurized, either by the front drive chamber 134 via the opening 156 or by the rear drive chamber 126 via the opening 155. The flush valve 140 would thereby be kept in its forward position and the piston hammer 124 will complete its forward stroke and begin the work cycle.

If the openings 155 and 156 are closed at start-up, pressurization of the rear drive chamber 126 will begin the forward movement of the piston hammer 124. The opening 155 would then open during the initial forward stroke and pressurize the piston area A1, as in the normal operating cycle.

If the piston hammer is at or near its front displacement limit, the openings 153 and 155 would be open at start-up. Pressurization of the rear pressure chamber 126 would pressurize the piston area A1 (via opening 155) 153). The spool valve 140 would be displaced to its rear position and lower the pressure in the rear drive chamber 126 and the piston area A2 (via the opening and allow the piston hammer 124 to initiate a reverse stroke by pressurizing the piston area 136.

Then assume that the flush valve 140 is at an intermediate position between its front and rear fixed positions. If the flush valve 140 is sufficiently far forward that the annular chamber 147 and the annular chamber 148 remain in communication, the start-up process will be identical to that described for the flush valve 140 when it is in the prime position, as described previously above .

If the flush valve 140 is at or near the rear fixed position, then the shoulder 149 prevents communication between the annular chamber 147 and the annular chamber 148. The rear drive chamber 126 will thus not be pressurized immediately at start-up.

If the piston hammer 124 is at its rearmost displacement limit (not shown), the openings 153 and 155 will be closed. Opening 156 would be open 10 15 20 25 30 35 524 375 "H'É2 pen. The open opening 156 communicates with the front drive chamber 134 and would pressurize the piston area A1 via the channel 154 and the annular chamber 145 and drive the spool valve 140 to its front fixed position.

The annular chamber 148 would now communicate with the annular chamber 147 and pressurize the rear drive chamber 126. Pressurizing the rear drive chamber 126 will cause the piston hammer 124 to start its forward stroke and begin the duty cycle.

If the piston hammer 124 is in an intermediate axial position (with the opening 153 closed), the openings 155 and 156 may be open or closed at the start-up. If either the opening 155 or 156 is open then the piston area A1 will be pressurized, either by the front drive chamber 134 via the opening 156 or by the rear drive chamber 126 via the opening 155. The flush valve 140 would thereby be driven to its front fixed position and the piston hammer 124 would complete its forward stroke and begin the work cycle.

If the openings 155 and 156 are closed at start-up, pressurization of the front drive chamber 134 will initiate the backward movement of the piston hammer 124 to begin the duty cycle (the rear drive chamber 126 is not yet pressurized). The opening 156 would then open during the initial reverse stroke and pressurize the piston area A1 as in the normal operating cycle.

If the piston hammer 124 is at or near its front displacement limit, the openings 153 and 155 would be open at start-up. However, the rear drive chamber 126 would not be pressurized, so that pressurization of the front drive chamber 134 will initiate the backward movement of the piston hammer 124 to start the duty cycle.

It will be appreciated that the hammer of standard NIN type described above is manufactured under the name “Water Powered ITH Hammer”, WASSARA model no. W100 / W1OOS.

This hammer has the property that when no force acts on the drill bit 114 and pressure is applied to the piston hammer 124, the pressurized liquid is flushed out of the channel through the piston hammer 124.

An example of an operating limitation for the liquid-powered hammer of standard NIN type, eg "Water Powered ITH Hammer", WASSARA model no. W100 / W100S described above, is illustrated in the following table 1.

Table 1 With a force of at least 300-500 lbs. applied to the drill bit, the fluid flow required to activate the hammer will be 15 to 20 gallons / min (gpm): 1) if it is desired NOT to ACTIVATE the hammer, the fluid flow will be limited by: a) that when the force acting on the drill bit is within about 0 to 500 lbs. the flow must be determined to be about 10 to 15 gpm: b) that when the force acting on the drill bit is greater than about 500 lbs. the maximum flow should be determined to a maximum flow (gpm) = 0.03 * force (lbs.): 2) if it is desired to ACTIVATE the hammer, the liquid flow should be determined to a minimum flow of: a) minimum flow (gpm) = 0.03 * force (lbs.) It will be appreciated as an alternative that it is possible to design a liquid-powered hammer so that the hammer does not work when there is no force acting on the drill bit. This is generally referred to as a flushing position / position. When the hammer is in the flushing position, the application of a force against the drill bit which is within a normal working interval will thus not activate the hammer. This design will hereinafter be referred to as an aggressive GIN type coil design, which is described as an example in US-5,014,796.

An aggressive liquid-driven coil hammer of the GIN type is manufactured by G-Drill AB in Sweden, and is commercially 10 15 20 25 30 35 n. U _ u. M, | o u u. n nu .u's: .u u a. u u u u »oc-» v u »f, nu n .. g of» en o. nu 1-. a. uno-e; nun: - u p nu o u I. u u n I c o - u u u: o a v u a. v: q u.- v »o. 34 available under the model designation GIN WlO0 / W10OS "G2".

As discussed above with reference to the standard NIN-type liquid-powered hammer, the aggressive GIN-type liquid-powered flush hammer referred to herein is usually also designed to be operated with relatively clean water as the propellant. It will be appreciated that when drilling fluid is used to drive the hammer, the standard GIN type fluid driven hammer may be modified. The internal clearances and materials used to construct the GIN hammer can, for example, be modified so that the hammer works properly at the relatively higher viscosity and the relatively high levels of contaminants that are usually found in drilling fluid.

Figs. 23a, 23b and 24 show an aggressive liquid-driven coil hammer of the GIN type generally designated 400. Since a brief description of the hammer 400 will be presented herein, a further description of the hammer 400 can be found in US-5,014 Referring now to Figs. 23a and 23b, there is shown a housing 418 for a rock drill 410 consisting of an elongated cylindrical tube of generally relatively uniform thickness, which has an inner annular support point 413. A cylinder 411, which is preceded by stepwise integrated with the valve housing 412, is received in the housing 418 and is supported by radially divided ring structures 414 and 415 resting against the support point 413. The cylinder 411 is fixed axially in the housing 418 by a tubular cylinder liner 416 extending between the rear front surface of the valve housing 412 and a rear support (not shown). The cylinder liner 416 is firmly threaded against a rear portion of the housing 418 and adapted to transmit rotation to the housing 418 in a conventional manner.

The inside of the cylinder liner 418 forms an opening 417, which is usually provided with ordinary drill pipes which use a high pressure liquid, preferably water. The water is supplied via the rear support and the opening and is used to drive the drill that is to go down into the hole. 10 15 20 25 30 35 I .. n. U n »a n n. N n u. v n. .n o o. 1 n q n. o .. .. q ~ nu ~. -. | .o u o .. v. v., »n. v.. -. ann .. ... u-. . n. 1 h. .u o. . f -. 1 n nu.

L - - u - g. Fig. 23b fragmentarily shows a drill bit 420 which is slidably received and retained in a sleeve 421 which is threaded towards the front end of the housing 418. An abutment 419 of the drill bit 420 protrudes into an annular shape. groove 422 of the sleeve 421. In the rearward direction from the groove 422, a guide bearing 423 is arranged in the sleeve 421.

The drill bit 420 has the usual flushing channel 424 therein which leads to its working end and the usual connection (not shown) with splines is arranged between the sleeve 421 and the drill bit 420, whereby rotation is transmitted to it from the housing 418.

An elongate chamber 425 is formed by the housing 418 and extends between the guide bearing 423 of the drill bit sleeve 421 and the divided annular structures 414 and 415 of the cylinder 411. The chamber 425 is constantly maintained at a lower fluid pressure, i.e. relieves the pressure due to one or more relief channels. connects the chamber 425 with the annular groove 422 which communicates with the flushing channel 424 in the drill bit 420.

A hammer 428 can reciprocate in the housing 418 to repeatedly deliver blows to the retainer 419 of the drill bit 420. A drive piston 429 is provided on the rear portion and preferably in the rear end of the hammer 420. The abutting front end of the hammer 428 is formed as a shaft pin 430 which is slidably received in the guide bearing 423 of the sleeve 421. A cylindrical, enlarged hammer part 432 is arranged so that it can move back and forth in the chamber 425. The diametrical for the function 432 has the function of increasing the impact energy of the hammer 428 and has a sufficient gap inside the chamber 425 to allow substantially unobstructed movement of low pressure liquid between the ends of the chamber 425 when the hammer 428 moves back and forth.

A reduced neck portion 431 is disposed between the piston 429 and the enlarged hammer portion 422 and preferably has a diameter equal to the diameter of the shaft pin 430. The neck portion 431 is sealingly enclosed by the radially 524 sections. JO divided the ring structures 414, 415 and can move freely back and forth therein.

An axial flushing channel 434 extends centrally through the hammer 428 and has at its rear part an enlarged bore 435 inside the piston 429, which is sealingly displaceable in a central low pressure or relief channel 438, which coaxially forms part of or is mounted on the cylinder. 411. The channel 438 is in open communication with the central piston channel 434 and with the inside of the valve housing 412.

The piston 429 is slidably and sealingly received in the cylinder 411 and forms a drive chamber 439 therein facing the rear end surface 440 of the piston 429, which chamber 439 is used to propel the hammer 428 forward in its working stroke.

Arranged around the reduced neck portion 431 is an opposite cylinder chamber 441 facing an annular opposite drive surface 442, which is smaller than the drive surface 440 and is adapted to force the piston 429 in the rearward direction to perform a return stroke of the hammer 428.

The valve housing 412 has an axial bore 445 in which a tubular control valve 446 (preferably a flush valve) is reciprocable. The inside of the control valve 446 is permanently open to the channel 438 and is thus retained at the lower liquid pressure in the flushing channels 434 and 424. The control valve 446 has a differential piston 447 which is sealing and slidably received in the axial bore 445, which is closed by a lid 448 which is threaded against the housing 412. The lid 448 slidably and sealingly receives therein an upper edge 449 of the control valve 446.

The opposite end of the control valve is a lower edge 451. A reduced waist 452 is disposed between the lower edge 451 and the differential piston 447. The outer diameter of the lower edge 451 is slightly larger than the outer diameter of the upper edge 449 and slightly smaller than the diameter of the bore 445. The bore 445 is terminated by an intermediate collar 450. Protruding guide tabs 454 10 15 20 25 30 35 524 575 ïfïsïšf 3 / (see Fig. 24) are arranged on the axial front surface of the lower edge 451 and act as guides when the control valve 446 reciprocates between the position in Fig. 23a, in which the lower edge 451 seals against the lower collar 453, and the position in Fig. 24, in which the lower edge 451 seals against the intermediate collar 450 .

Fluid channels 458 connect the high pressure port 417 via manifolds 459 with the valve hole 445 to provide a constant pressure on the underside of the differential valve piston 447, thereby pushing the control valve 446 toward the rear position shown in Fig. 24.

The fluid passage 460 connects the upper portion of the drive cylinder chamber 439 to the annular internal groove 455 in the valve housing 412.

During operation, the control valve 446 is adapted to reciprocate in response to the movement of the hammer 428, and, more specifically, in response to the position of the control groove 433 on the piston 429. Towards this end, control channels 461 extend, as shown in Figs. 23a and 24, to connect a control chamber 480 located at the upper end of the valve hole 445 with the cylinder wall between the chambers 439 and 441. These chambers are aligned with the piston control groove 433, which, as shown in position in Fig. 23a, the control channels 461 connect to the fluid channels 462 leading to the low pressure chamber 425. Upon unloading the upper end of the valve hole 445, the above-mentioned upwardly directed valve bias brings the control valve 446 up to its position in Fig. 24, wherein the lower valve edge 451 seals against the intermediate edge 450.

Thus, when the hammer 428 of Fig. 23b strikes the stop 419 and the upper end of the valve hole 445 is relieved, the higher pressure transmitted from the opening 417 via channels 458 and 459 to the lower end of the valve cavity 445 brings the control valve 446 to the position in Fig. 24. At this moment and until the hammer 428 under its upward bias has been moved to the position in Fig. 24, the drive chamber 439 will be discharged to the channel 438 via the channels 460 and the open lower edge 453. The effluent is passed through the channels 434 and 424 to flush out the hole drilled in the rock by the drill bit 420.

When the control channel 433 of the piston 429 reaches the rear position in Fig. 24, it connects the branch channels 463, which lead from the high pressure channels 458, to the channels 461. This pressurizes the end of the valve hole 445. Depending on the difference in diameter between the valve edges 459 and 451, the rear surface of the differential valve piston 447 is larger than the opposite mesh surface which provides the constant rearward bias of the valve piston 447, and as a result the control valve is brought back towards the position in Fig. 23a. The intermediate valve edge 450 is hereby opened and the drive cylinder chamber 439 is connected to high fluid pressure via the channels 458 and 459, the valve waist 452 and the channels 460. As a result, the hammer 428 is forced to perform its work stroke to strike the abutment 419 of the drill bit, see Fig. 23b. The operation described above is then repeated.

In a raised position of the rock drill, the drill bit 420 will sink in the forward direction slightly from the position shown in Fig. 23b. The enlarged portion 432 of the hammer 428 is gripped at such a moment and the hammer is stopped and lowered to a front hole 466 in the chamber 425. At the same time, the high pressure manifolds 463 are opened to drive the chamber 439. The chamber 439 is relieved of vigorous liquid flushing through the hole 467 ) into the channel 438 for the purpose of changing the impact energy of the exposed rock drill.

The chamber 425 can be combined with hammers which have enlarged parts 432 of varying length. Such a possibility is indicated by phantom lines for a hammer 468 in Fig. 23b. Water can be supplied to the opening 417 at approximately 180 bar (18 MPa). reciprocating motion is normally equalized by varying fluid requirements during hammer compression and re-expansion of the water column in the pipes supplying the drill 410 fluid, thereby avoiding the use of gas-filled downhole accumulators.

With a water pressure of 180 bar (18 MPa) and a drill casing diameter of eg 96 mm, the new valve design allows an impact energy of approximately 25-30 kW and a blow-out frequency close to 60 Hertz. The water consumption of approximately 150-200 l / min gives a flushing water speed of more than 0.6 m / sec, which at an achieved holding diameter of 116 mm is sufficient to effectively remove debris during vertical drilling.

It will be appreciated that the standard GIN type hammer described above includes the property that when no force acts on the drill bit 420 and pressure is applied to the piston hammer 428, the pressurized liquid is flushed out of the channel through the piston hammer 428.

An example of work restrictions for a liquid-powered hammer of standard GIN type, eg the model with no.

GIN W100 / WlOOS “G2” as described above is described in the following Table 2.

Table 2 1) If it is desirable NOT to ACTIVATE the hammer, perform the following sequence: a) Reduce the force to approximately zero; b) Use of a liquid flow in a size of 15 gpm to the liquid hammer, which results in the hammer switching to the flushing position; c) Regulation of the fluid flow and the compressive force acting on the drill bit so that: the minimum flow (gpm) = 0.025 x force (lbs.); or maximum force (lbs.) = 40 x the flow (gpm). 10 15 20 25 30 35 524 575 40 2) If it is desired to ACTIVATE the hammer, perform the following sequence: a) Reduce the liquid flow to the hammer to approximately zero; b) Use of a force of at least 500 lbs. c) Use of a liquid flow of at least 15 Qpm; d) and then regulate so that; minimum force (lbs.) = 4O x the flow (9Pm); or maximum flow (lbs.).

Referring now to Fig. 25, in one embodiment, (gpm) = 0.025 x the force includes a drill bit 210, which is constructed in accordance with the principles of the present invention, as main components, a probe holder / housing 214, a fluid driven hammer 216 and a drill bit assembly 218 connected with front end to rear end, as shown.

The drill head 210 may also include a starter rod 212.

The starting rod 212 connects at a rear part 213 to a conventional drilling line driven by a directional drilling machine. In one embodiment, drilling fluid is fed through the drilling line, the starting rod 212 and through a channel in the probe holder 214. The fluid is also used to drive the fluid driven hammer 216.

The drill bit assembly 218 includes a drill bit 219A with a row of cutting teeth 22OA and a drill bit shaft 221A (see Fig. 25B), which is used to mount the drill bit 219A toward the front end of the fluid driven hammer 216.

The drill bit 219A is releasably mounted to the shaft 221A by means of locking pins inserted through transverse heels 223. In one embodiment of the invention, angled openings 222A (see Fig. 25B) are provided in the drill bit assembly 218 to eject used fluid from the fluid driven the hammer 216 out of the front portion of the drill bit 219A.

The drilling fluid coming out of the angled openings 222A 10 15 20 25 30 35 t fl NJ 4> LN \ J LH 41 is used to transport drilling chips consisting of soil and / or rock chips from the path of the drill bit.

In one embodiment, a drill head 210 is provided which has a probe holder 214, the probe holder 214 including a coupling part. In one embodiment of the invention, the coupling member is a threaded member 250 which is adapted to connect to a threaded end of the liquid driven hammer 216. It will be appreciated, as discussed above, that a spline connection may be used to connect the probe holder 214 to either end of the fluid driven hammer 216 and the starter rod 212. The same type of locking pin connection, without splines, can be used to mount the drill bit 219A to the shaft 221A.

With further reference to Figs. 25 and 25A, the threaded end 250 is arranged so that a centerline or longitudinal axis "1" of the threaded end 250 (the curved axis) defines an angle med with the longitudinal axis "L" of the drill line. The angle kan can vary from about 0.5 ° to about 2 ° and is usually around 1.5 °. It will be appreciated, however, that the angle. Is limited by the fact that the drill head 210 may be used for drilling through both solid rock and compressible soils. In other words, when drilling in solid rock, the angle of the curved shaft cannot exceed a predetermined value so that the drill head 210 does not get stuck in the borehole. It will also be appreciated that the longitudinal mean / average axis L of the drill string can usually be determined close to or at the probe holder 214 and the starting rod 212.

The liquid-driven hammer 216 is coupled to the probe holder 214 so that the length of the liquid-driven hammer 216 forms an angle med with the longitudinal axis "L" of the drill line. The angle ger provides a displacement (or curved axis) for guiding the drill head 210. Those skilled in the art will readily appreciate that the pneumatic hammer 216 may also be connected to the threaded end 250 of the probe holder 214 in a similar manner. 10 15 20 25 30 35 524 375 ¿..:, ..: ¿m; a .v nu; When drilling in compressible material, such as earthworks, the operator can bend or steer the drill head 210 away from a straight path in a desired deviation direction using the bent shaft formed by the probe holder 210 and the liquid driven hammer 216. It may, if drilling in soil along a substantially horizontal direction, for example it may be desirable to redirect the drill head 210 in a substantially upward direction. This can be achieved by first rotating the entire drill line so that the part of the liquid-driven hammer 216, which extends furthest from the longitudinal axis "L" of the drill line, is directed towards the desired deviation direction. When placing the drill head 210 in the correct deviation orientation, the drill head 210 is advanced by inducing drilling forces from the directional drill. Accordingly, the path of the drill bit 210 deviates according to the orientation of the fluid driven hammer 216. This control operation is similar to that used when the drill head is equipped with a curved portion for deflecting or guiding the drill line.

It will be appreciated by those skilled in the art that the drill head 210 may be deflected or guided in the desired direction using various techniques depending on the properties of the medium being drilled. For example, to unfold or guide the drill head 210 when drilling through compressible soil, the drill head 210 is usually not rotated and the liquid hammer 216 may or may not need to be operated. Other types of soil, however, have properties which mean that in order to be able to bend the drill head 210 in the appropriate direction, the pressure force (eg the pressure) from the drill line alone may not be sufficient to bend the drill head 210. Therefore, in some types of soils, it may be desirable to apply blows to the drill bit 219A by using the liquid hammer 216 while changing the direction of the soils. On the other hand, when drilling in solid bedrock, the drill head 210 is usually not rotated and the deviation or control of the drill head 210 is achieved by striking the drill bit 219A with the liquid driven hammer 216. The drill head 210 then changes direction in the solid bedrock by using essentially the same shelving method as described above by using the pneumatic hammer 16. For example, by machining a shape that is almost circular but leaving a strip or strip rocks left on the bottom and repeat the process many times. The slope method described above provides a stepped shape with tapered elevations and straight steps of the type shown in Fig. 16. The action of the strip changes the inclination of the drill head, as described above, and helps to change the angular inclination.

There may also be other types of soils with properties so that the drill head 210 can be rotated about an arc less than 360 degrees (and / or maintained stationary) while simultaneously delivering blows on the drill bit 219A with the liquid driven hammer 216 to change direction in the soil. Again, this procedure can be achieved by using substantially the same slope method as described above when using the pneumatic hammer 16. Under certain conditions, while the drill string can be rotated during the deflection or control procedure, however, the blows from the liquid driven hammer 216 are not required.

Referring to Figure 25B, a sectional view of the drill bit assembly 218. In one embodiment of the invention, the drill bit assembly 218 is placed in a sleeve 217 having an inner surface 221 adapted to receive the drill bit assembly 218 and an outer surface 223 adapted to receive of the distal end of the fluid driven hammer 216. It will be appreciated that the inner surface of the sleeve 217 may be provided with various properties to receive a drill rod 221A, such as splines similar to the spline 72B of the drill rod 21A, as discussed above. Furthermore, the outer surface 223 of the sleeve 217 may be provided with threads for connecting the drill bit assembly 218 to the distal end of the fluid driven hammer 216 having a matching set of threads disposed therein.

It will be appreciated that a number of drill bit assemblies may be used and replaced with the drill bit assembly 218 without departing from the spirit and scope of the present invention. For example, the drill bit assembly 218 can be replaced with drill bits of the type described in WO 99/19596 and / or US-5,778,991 and other documents. Those skilled in the art will appreciate that the choice of a drill bit depends on the design choice, which is familiar to the trained mechanic.

With reference to Fig. 25, it will be appreciated that in one embodiment of the invention, the effective guide geometry of the drill bit 219A (e.g., a peripheral protrusion provided in the drill bit assemblies 18 and 218 or other drill bits which are "unbalanced" - e.g. drill bits with an asymmetrical shape and / or arranged and designed to cut in an asymmetrical manner) are aligned so that the effective guide geometry is placed at an extreme point from the longitudinal axis “L” of the drill line. Furthermore, the effective guide geometry of the drill bit 219A should be aligned along the axis "1" of the liquid driven hammer 216. Thus, the orientation of the probe 246 (see Fig. 22A) before use should correspond to the orientation of the liquid driven hammer 216 and the effective guide geometry of drill bit 219A.

Referring now to Figure 26A, the probe 246 is placed inside the probe holder 214 between the shock absorbers 255A-B. A probe indexing assembly 251 is disposed between the probe 246 and the shock absorber 255B.

The outermost part seen from the longitudinal axis "L" of the effective guide geometry to the drill bit 219A and the outermost point from the longitudinal axis "1" of the liquid-driven hammer 216 must correspond to the orientation of the probe 246. Therefore, it is adjusted. 4: the outermost part seen from the longitudinal axis "L" of the effective guide geometry to the drill bit 219A and the outermost part from the longitudinal axis "1" of the liquid driven hammer 216 so that they are in line. The probe indexing assembly 251 is arranged to perform the final orientation adjustments between the fluid driven hammer 216 and the drill bit 219A and the probe 246.

Referring now to Figures 26B-C, the probe indexing assembly 251 includes an enclosing probe cap 239 having an indexing surface 242 and an indexing tongue which includes a protrusion 241. An indexing cap 240 is provided which is connected to the enclosing probe cap 239. The indexing cap 240 includes an indexing surface 253 which mates with the indexing surface 242 of the enclosing probe cover 239. The indexing tongue projection 241 is adapted to be connected to a corresponding slot formed in the shock absorber 255B.

The enclosing probe cover 239 of the probe indexing assembly 251 includes a small protrusion 238. The enclosing indexing cover 239 is connected to the indexing cover 240 by means of a retaining bolt 243.

The retaining bolt 243 includes a retaining nut 244 and a retaining spring 245. The enclosing probe cover 239 is biased against the indexing cover 240 by the force of the retaining spring 245. The retaining force is adjustable by adjusting the retaining bolt 244.

In use, once the orientation between the effective guide geometry of the drill bit 210A and the fluid driven hammer 216 is well fixed, the final adjustment is completed by indexing (e.g., rotating) the probe indexing assembly 251 and the probe 246 simultaneously, to bring all the three elements (e.g., the probe 246, the fluid driven hammer 216, and the effective guide geometry of the drill bit 219A) in their proper direction. Once the three elements are adjusted, the orientation of the probe 246 can be used to determine the direction of deviation of the drill line. to bend off the drill track through solid bedrock. Those skilled in the art will of course appreciate that indexing of the three elements can be achieved by using other techniques and constructions without departing from the scope of the present invention.

Referring now to Figure 27, there is shown a system 300 for drilling a hole including a directional drill 302. The directional drill 302 includes a frame 304 having a drive member 306 for feeding and threading tubes. The directional drill 302 is used to push a drill string 308 with tubing into the ground to drill a hole.

Thus, a compressive force is provided along the axis of the drill line by the directional drilling machine 302 by means of drive part 306 to push the drill line 308 into the ground.

The directional drill 302 is also equipped with a pressure source 320 which is used to provide working pressure to be transmitted by the liquid for operation of liquid driven hammers of the types described above (e.g. a liquid driven hammer of standard NIN type and / or an aggressive liquid driven spool hammer of GIN type).

The hole drilling system 300 may also include a control unit 322 for monitoring and regulating the thrust provided by the drive member 306.

The control unit 322 can also be adapted for monitoring and regulating the pressure source 320.

It will be appreciated that the control unit 322 may be a computerized control box which includes one or more microprocessors and various other control circuits.

Examples of electronics control modules for performing these functions are described in U.S. Patent Application Serial No. 09 / 405,889, "REAL-TIME CONTROL SYSTEM AND METHOD FOR CONTROLLING AN UNDERGROUND BORING MACHINE" filed September 24, 1999, and U.S. Patent 5,944,121, both of which 10 15 20 25 30 35 is hereby incorporated in its entirety by reference.

Those skilled in the art will, of course, appreciate that an operator 324 of the directional drill 302 also has the ability to manually control the pressure force and pressure by operating control valves and observing parameter gauges which display pressure and pressure force measurements.

The drilling system also includes a drill head 310 at a distal end of the drill string 308. The drill head 310 includes a probe holder 314 with a probe 346, a percussion hammer 316 and a drill bit 319. A starting rod may also be included in the drill head 310. A positioner 326 above ground determines the position of the probe 346.

In use, the pressurized fluid is supplied in channels provided through the drill string 308 to operate the fluid hammer 316. As described above, the fluid hammer 316 dispenses shocks to the drill head 319 to drill in various types of soil. However, the percussion operation of the liquid hammer 316 is sometimes desirable and sometimes not. The present invention thus also provides a method for controlling the ON / OFF states of the percussion hammer 316.

Referring now to Figures 28 and 29, methods for ON / OFF control of the impact hammers (eg pneumatic or hydraulic hammers) are shown. Figure 28 shows an embodiment for ON / OFF control of a liquid-driven hammer of standard NIN type and Figure 29 shows an embodiment for ON / OFF control of an aggressive liquid-driven coil hammer of GIN type. It will be appreciated that these basic modes of operation may be applied to pneumatic hammers, similar to the pneumatic hammer 16 described above, provided that the limit pressures are properly adjusted for operation of the pneumatic hammer with a compressible fluid.

Those skilled in the art will appreciate that the following methods may be performed by the operator of the directional drill or of an electronic control module (hereinafter referred to as the control unit) for the directional drill 10 15 20 25 30 35 ñ, - F. ".". .... ... .....

. H H. .. ... .... ". ...... .. ....." .... ... ..... .... . . .... ... , .. _ 48 machine. An example of an electronic control module for performing these functions is described in U.S. Pat. in its entirety by reference.

Figure 28 shows a flow chart 258 of an embodiment of a method for ON / OFF control of a liquid-driven hammer of standard NIN type. Those skilled in the art will appreciate that these basic working methods are applicable to a pneumatic hammer, similar to the pneumatic hammer 16 described above, provided that the limit pressure is suitably adjusted for operating a pneumatic hammer with a compressible fluid.

An example of the operating limitations of a standard NIN type liquid-powered hammer is the following: with a force of at least 300-500 lbs. Applied to the drill bit, the liquid flow required to activate the hammer will be 15 to 20 gallons per (gpm) . l) If it is desirable NOT to ACTIVATE the hammer, the fluid flow will be limited by: minute a) when the force acting on the drill bit is within about 0 to 500 lbs the maximum flow must be set to approximately 15 gpm; b) when the force acting on the drill bit is greater than approximately 500 lbs, the maximum flow should be set to a maximum flow (gpm) = 0.03 x force (lbs.); 2) If it is desirable to ACTIVATE the hammer, the liquid flow should be set to a minimum flow of: a) the minimum flow (gpm) = 0.03 x force (lbs.).

According to this, the operator or control unit, at box 260, chooses whether to use the stroke function of the hammer. If the percussion function is not selected, at box 262, 10 15 20 25 30 35 CH ßà 4> 1 ~ J LH 49, the operator or control unit restricts the fluid flow at the directional drill to a level below a limit required to activate the standard NIN liquid-powered hammer -type.

Then, at box 264, while maintaining the fluid flow below the limit value required to activate the standard NIN-type liquid hammer, the pressure force from the directional drill is adjusted to a level below a limit level required to activate the liquid hammer of standard NIN type. Since there is a relationship between the pressure force and the flow, if the flow exceeds a predetermined magnitude, the pressure force can then be kept below a certain level to ensure that the hammer is not activated. An example of a sequence includes setting a flow to a desired level and then applying a compressive force. Alternatively, a compressive force can first be applied to a desired level and then the flow is adjusted. The flow rate can, for example, initially be set to 15 gpm without any compressive force being applied. Once the compressive force reaches, for example, 500 lbs, the flow (gpm) can then be increased to a ratio of 0.03 x force (lbs).

At box 266, the compressive force is maintained at a level below which the liquid hammer will not be activated. Furthermore, if rotation of the drill line is required during the drilling process, the compressive force is limited to a level below the limit value required to activate the standard NIN-type liquid-powered hammer.

If the operator or control unit at box 260 chooses to use the impact function of the hammer, the procedure proceeds to box 270. At box 270, the liquid flow is increased to a level above the limit value required to activate the liquid hammer. Alternatively, the compressive force provided by the directional drill is increased to a level above the limit value required to activate the liquid hammer.

Figure 29 shows a flow chart 278 for an embodiment of a ON / OFF control method of a now grinding liquid-driven GIN-type spool hammer. Those skilled in the art will recognize that these basic modes of operation are applicable to a pneumatic hammer, similar to the pneumatic hammer 16 described above, provided that the limit pressure is suitably adjusted for operation of a pneumatic hammer with a compressible fluid.

As discussed above, an example of operating constraints for an aggressive liquid GIN type flushing hammer is as follows: 1) If it is desired NOT to ACTIVATE the hammer, perform the following sequence: a) reduce the force to approximately zero; b) using liquid flow in a size of 15 gpm to the liquid hammer, which results in the hammer switching to the flushing position; c) then the fluid flow and the compressive force acting on the drill bit are regulated so that: (gpm) = 0.025 x force (lbs); (1bs) = 40 x the flow (gpm). 2) If it is desired to ACTIVATE the hammer, the following sequence is performed: the minimum flow or maximum force a) Reduction of the liquid flow to the hammer to approximately zero; b) Use of a force of at least 500 lbs. c) Use of a liquid flow of at least 15 gpm; d) and then regulate so that: the minimum force (lbs) = 40 x the flow (gpm); or maximum flow (gpm) = 0.025 x the force (lbs) At box 280, the operator or control unit selects whether to use the impact function of the hammer. If the percussion function is selected, at box 282, the operator or control unit reduces the compressive force provided by the directional drill while maintaining the drilling fluid pressure in the drill line. The combination of reducing the compressive force and maintaining the drilling fluid pressure forces the drill bit to move forward in the drilling direction and thereby switches the aggressive liquid-driven spool hammer of the GIN type to its spooling position. In the flushing position, the driven hammer 316 does not move back and forth and the drilling fluid exits only through the openings 222A.

At box 284, the drilling process now proceeds in a conventional manner without the aid of the impact action of the aggressive liquid-driven coil hammer of the GIN type. It will be understood that the compressive force cannot be applied when “mud flow”) inside the drilling line because the application of a compressive force lacks drilling fluid (eg sludge flow, without having drilling fluid pressure would cause the drill bit 2l9A to move backwards in the direction of the directional drill.

Furthermore, the drilling fluid flow, pressure or flow size should be regulated within certain predetermined limits, which will vary as a function of the compressive force.

It will be appreciated that the constraints may be controlled automatically by the control unit.

At box 286, the liquid hammer is monitored to determine if it has been inadvertently activated. If not, the effortless drilling continues. Otherwise, the procedure continues at block 282 until the operation of the driven hammer 316 ceases.

If the operator or control unit selects the percussion function of the hammer at box 280, the procedure switches to box 288 where the drilling fluid flow is then significantly reduced to approximately zero. As indicated in box 290, a compressive force is then applied to the drill line by the directional drilling machine so that the drill bit 219A is forced to move backwards towards the directional drilling machine, thereby shifting the aggressive liquid-driven GIN-type spool hammer from its spooling position.

At box 292, the operator or control unit then increases the drilling fluid flow until the aggressive liquid-driven flush hammer of the GIN type begins the striking procedure and the drilling process continues. The operator or control unit 10 15 c_ \ '} T! v. .-. . . 524 3 DA then regulates the drilling fluid flow as a function of the pressure force so that if the drilling pressure force is small, the drilling fluid flow is reduced to avoid the aggressive liquid-driven flush hammer of the GIN type accidentally switching to the flushing position.

At box 296, the aggressive GIN-type flush hammer is monitored to determine if it has been accidentally turned off. If not, the percussion drilling continues. Otherwise, the process continues at box 288 until the percussion operation of the aggressive liquid-powered GIN-type spool hammer begins.

While certain embodiments of the invention have been shown intended for this description, many changes in the method and apparatus of the invention presented herein may be made by those skilled in the art, such changes being realized within the scope and spirit of the present invention, as defined. in the appended claims.

Claims (9)

10 15 20 25 30 35. . ». n. 53 NEW REQUIREMENTS A method of operating a hammer (100, (300) adapted for drilling through rock and 216, 400) in 216, 400) in a horizontal directional drilling apparatus with a drill line (308) of compressible soil, the hammer (100, (300) is driven by a liquid and the method of (100, 216, 400) (a) regulating the thrust from a drive member (308), regulating the thrust to a predetermined level of force, and the drilling apparatus operating the hammer comprises: (306) wherein the drilling apparatus (300) against the drill line (b) regulating the liquid flow (320) to drive the hammer (100, 216, 400), the liquid flow being regulated to a predetermined flow level corresponding to the predetermined power level so that the predetermined flow level and the predetermined power level to activate and deactivate the hammer (100, 216, 400). The method of claim 1, wherein the hammer (100, 216, 400) is an aggressive flush type hammer (400) and drilling is performed in bedrock, the method of operating the aggressive flush type hammer (400) further comprising; (a) decision to activate the aggressive coil type (400); (b) reducing the flow of liquid to drive the hammer the pre-determined flow level of the hammer (400) is very close to zero; and to the predetermined flow level, wherein (c) applying the predetermined force level of the compressive force, the predetermined force level exceeding a predetermined force limit value for the drive member (306) (300) (308), the aggressive coil type hammer (400) of the drilling apparatus against drill line and do so switch from a flushing position; and (d) increasing the fluid flow from the predetermined flow level and continuing the drilling in the rock with the activated aggressive coil type hammer (400). A method according to claim 1, wherein the hammer (100, (100) 216, 400) is a standard type hammer and the drilling is performed 10 15 20 25 30 35 524 375 »« =. I '' SH in rock, wherein the method of operating the standard type hammer (100) further comprises: (a) determining to activate the standard type hammer (100); (b) increasing the liquid flow for operating the hammer (100) to the predetermined flow level, the predetermined flow level having a value greater than the predetermined flow limit value; (c) applying the predetermined force level of the compressive force, the predetermined force level exceeding a predetermined force limit value for the drive member (306) of the drilling apparatus (300) against the drill string (308); and (d) continuing drilling in the bedrock with the standard type hammer (100) activated. The method of claim 1, wherein the hammer (100, 216, 400) is an aggressive coil type hammer (400) and the drilling is performed in compressible soil, the method of driving the aggressive coil type hammer (400) further comprising: (a) determining to deactivate it aggressive coil (400): (b) reducing the compressive force to the predetermined type hammer force level, the predetermined force level being lower than a predetermined force limit value for the drive member (306) of (300) (308); (c) maintaining the fluid flow to drive (400) the aggressive coil type hammer (400) switches to a coil drilling apparatus against the drill line hammer at the predetermined flow level so that the position; and (d) continuing drilling in compressible soils without having the aggressive coil type hammer (400) activated. The method of claim 1, wherein the hammer (100, 216, 400) in compressible soil, the method of maneuvering being a standard type hammer (100) and the drilling performed, the standard type hammer (100) further comprising: (a) determining to deactivate the standard type hammer (100) ; 10 15 20 25 30 35 524 375 'S5 Q; <. .o (b) reducing the liquid flow to drive the hammer (100) to the predetermined flow level, the predetermined flow level being lower than a predetermined flow limit value required to activate the hammer (100); (c) reducing the compressive force to the predetermined force level, the predetermined force level having a value lower than a predetermined force limit value which (100): (d) continuing the drilling in compressible soil is required to activate the hammer and without the standard type hammer (100) activated. A method of operating an aggressive coil type hammer (400) in a horizontal directional drilling apparatus (300) with a drill line (308) adapted to drill through rock and compressible soil, the aggressive coil type (400> (300) and the method to drive the aggressive coil type hammer (400) the hammer in the drilling apparatus is driven by a liquid, comprises: determining whether to activate the aggressive (400); (a) whether drilling takes place in rock and the hammer (400) coil type hammer is to be activated: reducing the fluid flow for operating the hammer (400) to a first value very close to zero; applying a compressive force exceeding a pre- (306) so that the hammer determines the limit value by means of a drive part of (300) (308) (400) changes from a flushing position; and the drilling device against the drilling line increases the liquid flow to a predetermined limit value and continues drilling in the rock with the hammer (400) activated; (b) if drilling is carried out in compressible soil and the hammer (400) is not to be activated: mi reducing the pressure force below a predetermined limit value while maintaining the liquid pressure above a predetermined limit value on the hammer (400), whereby the hammer (400) changes to the coil position; and l0 15 20 25 30 35 524 375 56 continuation of drilling in compressible soil (400) A method according to claim 6, wherein, without the hammer being activated. if the hammer (400) is activated: the liquid flow is regulated as a function of the pressure force, whereby, if the pressure force is lower than a predetermined limit value, the liquid flow is reduced to a level lower than a predetermined limit value to prevent the hammer (400) from shifting to the flush position. A method according to claim 6, wherein, if the hammer (400) is not activated: the drive part (306) of the drilling apparatus (300) is regulated so that a compressive force is not applied when liquid flow is lacking. (100) in with a drill line A method of operating a standard type hammer (300) (308) adapted to drill through rock and get a horizontal directional drill pressable soil, the standard type hammer (100) in (300) driving the standard type hammer driven by a liquid and the method of ( 100) determining whether to activate the default type (l00); (a) if drilling is carried out in rock and the hammer (100) the drilling apparatus comprises: the hammer shall be activated: increasing the liquid flow to a value above a predetermined limit value; increasing the compressive force provided by a drive member (306) to a value above a predetermined limit value; and in the horizontal drilling apparatus (300) continuing the drilling in the rock with the hammer (100) activated; (b) if drilling takes place in compressible soil and the hammer (l00) is not to be activated; limiting the fluid flow to a value lower than a predetermined limit value required to activate the hammer (100); U now limiting the compressive force to a value lower than a predetermined limit value required to activate the hammer (100); and continuing drilling in the compressible soil without having the hammer (100) activated.