Percussion Drilling Tools and Method for Removing a Percussion Drill Bit from a Percussion Drilling Tool
Patent Information
- Application Number
- BR112022019702
- Authority / Receiving Office
- BR · BR
- Patent Type
- Patents
- Current Assignee / Owner
- Publication Date
- 2026-09-08
Smart Images
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Abstract
Description
1 / 22 Percussion Drilling Tools and Method for Removing a Percussion Drill Bit from a Percussion Drilling Tool Field of Invention
[0001] The present invention relates to cleaning and connection arrangements for fluid-operated percussion drilling tools. In particular, the invention relates to cleaning and connection arrangements for use in down-the-hole hammers. Background for the Invention
[0002] Percussion drills for fluid-operated percussion drilling tools, such as down-the-hole hammers, typically comprise a drill head populated with cutting inserts on the front face of the head. The drill head is formed with an axially extending rod having a diameter smaller than that of the drill head. As the hammer rotates, rotational drive is most commonly transmitted to the rod by means of keys provided on the outer cylindrical wall of the rod that mesh with keys provided internally in a drive mandrel of the drilling tool. During the drilling cycle, an impact piston strikes a rear end of the rod, forcing the cutting inserts in the drill head into the rock being drilled. Pressurized air, known as cleaning air, is used to remove chips from the hole while the hammer operates.Cleaning air can be supplied through a discharge hole through the center of the piston and a corresponding hole through the drill rod. However, this arrangement typically requires a... Petition 870260009089, dated 01 / 30 / 2026, page 15 / 80 2 / 22 foot valve, which may be prone to rupture, to control the cleaning air. Furthermore, the piston's striking area is reduced because of the central bore, which also reduces the piston's weight. The piston's lifting surface area is also reduced. An alternative is to have the cleaning air displaced along the keys, with channels provided in the drill head to direct the air from the keys to the cutting face of the drill bit. As the keys require lubrication, lubricating oil can be added to the cleaning air flow at the drilling rig.
[0003] Irish Patent Number S87042 proposes an alternative arrangement to the conventional grooved fitting between the drive means of the drilling tool and the drill bit, in which a drive ring is provided with a plurality of protrusions at its front end, each of which is received into one of a corresponding plurality of recesses in the drill bit head. Since the fitting means are provided in the drill bit head part, the length of the drill bit can be reduced, thereby reducing the overall weight of the drill bit, enabling faster and more efficient drilling. It is desirable to provide a cleaning arrangement for use with this drive mechanism, and others, which allows for increased piston weight and striking area and optimizes the piston-to-drill bit mass ratio. Summary of the Invention
[0004] According to the present invention, a fluid-operated percussion drilling tool is provided comprising: an outer wear glove comprising a wall Petition 870260009089, dated 01 / 30 / 2026, page 16 / 80 3 / 22 substantially cylindrical and having internal and external surfaces; a percussion drill bit having a head portion and a drill bit retention portion and located at a front end of the outer wear sleeve; A sliding piston mounted for reciprocating motion inside the outer wear sleeve to strike the percussion drill bit; an actuating ring having a substantially cylindrical wall and comprising connecting means adapted for connecting the actuating ring to actuating means of a fluid-operated percussion drilling tool; at least one discharge channel to provide a fluid path to the cutting face of the drill bit for a discharge medium, represented in which a first part of the at least one discharge channel extends longitudinally within the wall of the wear sleeve, a second part of the at least one discharge channel extends longitudinally within the wall of the drive ring, and a third part of the at least one discharge channel extends through the head part of the percussion drill bit to the cutting face of the drill bit.
[0005] The first part of the discharge channel or channels is internal to the substantially cylindrical wall of the outer wear sleeve. That is, it is disposed within and extends longitudinally through the wall of the wear sleeve rather than being disposed within an inner surface of the wear sleeve itself. Thus, the first part of the discharge channel or channels extends Petition 870260009089, dated 01 / 30 / 2026, p. 17 / 80 4 / 22 longitudinally through the wall of the wear sleeve between an inner surface of the wear sleeve and an outer surface of the wear sleeve. Similarly, the second part of the or of each discharge channel is internal to the substantially cylindrical wall of the drive ring. Again, the second part of the discharge channel is disposed within and extends longitudinally through the wall of the drive ring rather than being disposed within the drive ring itself. Thus, the second part of the or of each discharge channel extends longitudinally through the wall of the drive ring between an inner surface of the drive ring and an outer surface of the drive ring.
[0006] The term “forward” as used in this document is intended to indicate a direction toward the cutting face of the drill bit. The term “back” or “rear” as used in this document is intended to indicate a direction away from the cutting face of the drill bit.
[0007] This arrangement is advantageous because the requirement for a foot valve and a central discharge hole through the piston is avoided. This allows the piston weight to be maximized and the piston striking area to be increased, thereby providing increased driving force and increased piston lifting force. Piston impact is also spread over a larger contact area which can improve piston longevity. An additional advantage of this arrangement is that the cleaning fluid is discharged onto the cutting face of the drill bit.
[0008] In one embodiment of the invention, for example, wherein the percussion drilling tool is operated by Petition 870260009089, dated 01 / 30 / 2026, p. 18 / 80 5 / 22 fluid is a pneumatically operated percussion drilling tool; the air used to drive the piston can also be used as the discharge medium. In this embodiment, the first part of the discharge channel has a first inlet on an inner surface of the outer wear sleeve and an outlet at a forward end of the outer wear sleeve wall. The first inlet may be arranged to exhaust air from an upper chamber of the fluid-operated percussion drilling tool. The first part of the discharge channel may have a second inlet on an inner surface of the outer wear sleeve, wherein the second inlet is located in a different longitudinal position along the wear sleeve than the first inlet. For example, the second inlet may be located ahead of the first inlet. The second inlet may be arranged to exhaust air from a lower chamber of the fluid-operated percussion drilling tool.
[0009] In another embodiment, for example, where the fluid-operated percussion drilling tool is a hydraulically operated percussion drilling tool, the tool may receive an air supply for use as a discharge medium. In this embodiment, the first part of the discharge channel has an inlet on an inner surface of the outer wear sleeve and an outlet at a forward end of the outer wear sleeve wall. Since the cleaning air is supplied independently of the tool's drive mechanism, a second inlet is not required.
[0010] The second part of or of each discharge channel Petition 870260009089, dated 01 / 30 / 2026, page 19 / 80 6 / 22 may have an inlet at a rear end of the drive ring and an outlet, wherein the inlet is arranged to receive the discharge medium from the outlet of the first part of the discharge channel. In some embodiments, the outlet of the second part of the discharge channel or channels may be provided on an inner surface of the drive ring. In some embodiments, the outlet of the second part of the discharge channel or channels may be provided at a front end of the drive ring.
[0011] The third part of or of each discharge channel may have an inlet on a percussion drill head part and an outlet on a percussion drill cutting face, wherein the inlet is arranged to receive the discharge medium from the outlet of the second part of the discharge channel.
[0012] The fluid-operated percussion drilling tool may also comprise fitting means on the insertable percussion drill with complementary fitting means on the drive ring by which the rotational drive of the drive ring may be transmitted to the percussion drill.
[0013] Preferably, the fitting means are provided in the head part of the percussion drill. In one embodiment, the fitting means in the head part of the percussion drill comprise a plurality of recesses and the complementary fitting means in the drive ring comprise a corresponding plurality of protrusions at a forward end thereof, whereby each protrusion is received within a corresponding recess to transmit rotational drive from the drive ring to the percussion drill. In a Petition 870260009089, dated 01 / 30 / 2026, page 20 / 80 7 / 22 alternative embodiment, the fitting means on the head part of the percussion drill comprise a plurality of protrusions and the complementary fitting means on the drive ring comprise a corresponding plurality of recesses, whereby each protrusion is received within a corresponding recess to transmit rotational drive from the drive ring to the percussion drill.
[0014] One advantage of this arrangement is that the drill weight is reduced because of the provision of the fitting means in the drill head, allowing the piston-to-drill mass ratio to be optimized. Furthermore, since the fitting means are provided in the drill head, a grooved shank is no longer required, thus also removing the need for keyway lubrication. The shank can also be shortened, or eliminated entirely.
[0015] In one embodiment, the second part of the discharge channel has an outlet at one of the protrusions on the drive ring. The outlet may be provided on an inner surface of the protrusion. Alternatively or additionally, the outlet may be provided at a forward end of the protrusion. A plurality of discharge channels may be provided such that each protrusion on the drive ring has an outlet for the discharge medium. In some embodiments, more than one outlet may be provided at each protrusion. The exact location and orientation of each outlet(s) may be selected to optimize the outlet angle for the cleaning fluid, to ensure that the cleaning fluid is effectively directed. Petition 870260009089, dated 01 / 30 / 2026, page 21 / 80 8 / 22
[0016] In another embodiment, the second part of the discharge channel has an outlet between two adjacent protrusions on the drive ring. The outlet may be provided on an inner surface of the drive ring. Alternatively or additionally, the outlet may be provided at a forward end of the drive ring. A plurality of discharge channels may be provided such that an outlet for the discharge medium is provided between each pair of adjacent protrusions.
[0017] The drive ring may comprise a plurality of separable segments of annular drive teeth. Each drive tooth segment may comprise one or more of the plurality of protrusions.
[0018] The fluid-operated percussion drilling tool may further comprise drill retention means adapted for engagement with the drill retention portion of the percussion drill to retain the percussion drill in the drilling tool. The drill retention means may comprise a protrusion formed internally in the drive ring for engagement with the drill retention portion of the percussion drill to retain the percussion drill in the drilling tool. In other embodiments, the drill retention means may comprise a drill retention ring. The drill retention portion of the percussion drill may comprise a retention protrusion.
[0019] The fluid-operated percussion drilling tool may further comprise an annular flange arranged around the outer wear sleeve in a Petition 870260009089, dated 01 / 30 / 2026, page 22 / 80 9 / 22 front end thereof. The flange may be prevented from moving forward relative to the wear sleeve by fitting an internal shoulder provided on the flange with an external shoulder provided on a front end of the wear sleeve. The drive ring connection means may comprise an annular collar provided on a rear end of the drive ring, arranged to receive a front end of the wear sleeve such that a front end of the wear sleeve rests on an internal shoulder against the drive ring. A plurality of holes may be provided on a rear end of the collar, which may be in contact with a front end of the flange.The flange may comprise a plurality of through holes provided therein, wherein each through hole corresponds to one of the plurality of holes in the collar, and wherein each through hole and corresponding hole in the collar are configured to receive a fastener, such as a screw, for connecting the drive ring to drive means of the percussion drilling tool. The through holes in the flange and / or the holes in the collar may be internally threaded.
[0020] According to another aspect of the present invention, a fluid-operated percussion drilling tool is provided comprising: an outer wear glove comprising a substantially cylindrical wall and having inner and outer surfaces; a percussion drill bit having a head portion and a drill bit retention portion and located at one end Petition 870260009089, dated 01 / 30 / 2026, page 23 / 80 10 / 22 front of the outer wear sleeve; A sliding piston mounted for reciprocating motion inside the outer wear sleeve to strike the percussion drill bit; an actuating ring having a substantially cylindrical wall and comprising connecting means adapted for connecting the actuating ring to actuating means of the fluid-operated percussion drilling tool; and an annular flange arranged around the outer wear sleeve at a forward end thereof, wherein the flange comprises a plurality of through holes provided therein and is prevented from moving forward relative to the wear sleeve by the engagement of an inner shoulder provided on the flange with an outer shoulder provided on a forward end of the wear sleeve; and wherein the drive ring connection means comprise an annular collar provided at a rear end of the drive ring, the collar comprising a plurality of holes provided at a rear end thereof, wherein each hole corresponds to one of the plurality of through holes in the flange, the collar arranged to receive a front end of the wear sleeve such that a front end of the wear sleeve rests on an inner shoulder of the drive ring and the rear end of the collar is arranged to be in contact with the front end of the flange and wherein each through hole and corresponding hole in the collar are configured to receive a fastener for connecting the ring Petition 870260009089, dated 01 / 30 / 2026, page 24 / 80 11 / 22 drive system for the percussion drilling tool.
[0021] A drill retaining ring may be arranged to fit with the drill retaining part of the percussion drill to retain the drill in the percussion drilling tool. The drill retaining ring may be secured in place between the drive ring and an aligner by fitting the fasteners with the drive ring.
[0022] The drill retaining ring may be provided as a plurality of annular drill retaining part pieces and the depth of the holes in the drive ring collar may be greater than the height of the drill retaining parts such that the percussion drill is removable from the drilling tool by retracting the hole holders by a distance equal to or greater than the height of the drill retaining parts, but less than the depth of the holes such that, when the outer wear sleeve is displaced away from the percussion drill, an annular space is formed between the leading end of the wear sleeve and the inner shoulder of the drive ring, to which the drill retaining parts are movable in an outward radial direction such that they no longer retain the percussion drill in the drilling tool.
[0023] The fluid-operated percussion drilling tool may further comprise an O-ring arranged around the drill retaining parts. Alternatively, the fluid-operated percussion drilling tool may comprise a plurality of pins extending through the drive ring and Petition 870260009089, dated 01 / 30 / 2026, p. 25 / 80 12 / 22 arranged to fit into the drill bit retention parts.
[0024] According to one aspect of the invention, a method is provided for removing a percussion drill bit from a fluid-operated percussion drilling tool as previously described, the method comprising: retract the hole holders by a distance equal to or greater than the height of the drill bit retaining parts, but less than the depth of the holes; Move the outer wear sleeve and the drive ring away from each other to create an annular space between the front end of the wear sleeve and the inner shoulder of the drive ring; and move the drilling tool and the percussion drill bit away from each other, such that the drill retaining part of the percussion drill bit causes the drill retaining parts of the drill retaining ring to move radially outward in the annular space.
[0025] The method may additionally replace the percussion drilling bit, and may additionally comprise: Insert a percussion drill bit into the distal end of the percussion drilling tool; Displace the drill retaining parts of the drill retaining ring in a radial inward direction by driving a plurality of pins extending through the drive ring and arranged to engage with the drill retaining parts; and move the outer wear sleeve in the direction of the drill bit. Petition 870260009089, dated 01 / 30 / 2026, p. 26 / 80 13 / 22 of percussion and reinsert the fasteners into the holes.
[0026] According to one aspect of the invention, the fluid-operated percussion drilling tool is a down-the-hole hammer. Brief Description of the Drawings
[0027] Figure 1 is a longitudinal section of a down-the-hole hammer according to a first embodiment of the invention; Figure 2 is a cutaway perspective view of the hammer drive ring in Figure 1; Figure 3 is a perspective view of the down-the-hole hammer in Figure 1; Figure 4 is an exploded view of some of the components of the hammer in Figure 1; Figure 5 is a longitudinal section of the down-the-hole hammer of Figure 1, showing the piston at the top of the stroke; Figure 6 is a longitudinal section of part of a down-the-hole hammer according to a second embodiment of the invention; Figure 7 is a perspective view of a segment of the hammer drive ring from Figure 6; Figure 8 is an exploded view of some of the components of the hammer in Figure 6; Figure 9 is an exploded view of a drill retaining ring for use in the down-the-hole hammer of Figure 1; Figures 10A to 10D are longitudinal sections of the down-the-hole hammer from Figure 1, showing the removal of the drill bit from the hammer; Figure 11 is a perspective view of the percussion drill and hammer drive ring of Figure 1; and Petition 870260009089, dated 01 / 30 / 2026, page 27 / 80 14 / 22 Figure 12 is a longitudinal section of a down-the-hole hammer according to an embodiment of the second aspect of the invention. Detailed Description of the Drawings
[0028] A down-the-hole hammer 1 according to a first embodiment of the present invention is illustrated in Figures 1 to 5. The hammer 1 comprises an outer wear sleeve 2 comprising a substantially cylindrical wall 3 and having inner 4 and outer 5 surfaces. The hammer also comprises a percussion drill 6 having a head portion 7 and a drill retention shoulder 8. The drill is located at a forward end 9 of the outer wear sleeve. The hammer further comprises a sliding piston 10 mounted for reciprocating motion within the outer wear sleeve to strike the percussion drill. A drive ring 11 having a substantially cylindrical wall 12 comprises connecting means 13 adapted for connecting the drive ring to hammer drive means. A drill retention ring 21 is arranged to engage with the drill retention shoulder 8 on the percussion drill to retain the drill in the hammer.
[0029] As shown more clearly in Figure 4, a plurality of recesses 14 is provided at a rear end 15 of the head part 7 of the percussion drill 6. A corresponding plurality of protrusions 16 is provided at a front end 17 of the drive ring 11. Each protrusion 16 is received within a corresponding recess 14 to transmit rotational drive from the drive ring 11. Petition 870260009089, dated 01 / 30 / 2026, page 28 / 80 15 / 22 for the percussion drill bit 6.
[0030] The hammer further comprises an annular flange 18 arranged around the outer wear sleeve at the forward end 9 thereof. The flange is prevented from moving forward relative to the wear sleeve by the engagement of an internal shoulder 19 provided in the flange with an external shoulder 20 provided in a forward end of the wear sleeve. The drive ring connection means 13 comprise an annular collar 22 provided in a rear end 23 of the drive ring, arranged to receive the forward end 9 of the wear sleeve such that the forward end of the wear sleeve rests on an internal shoulder 24 of the drive ring. A plurality of internally threaded holes 25 are provided in a rear end 26 of the collar, and the rear end of the collar is arranged to be in contact with a forward end 27 of the flange 18. A plurality of through holes 28 are provided in the flange.Each through hole corresponds to one of the plurality of holes in the collar. A screw 30 is inserted into each through hole 28 and screwed into the corresponding hole 25 in the collar to connect the drive ring to the wear sleeve and thus to the drive means of the percussion drilling tool.
[0031] The clamping effect of this screwed arrangement also retains the drill retaining ring 21 in place between the drive ring 11 and an aligner 29.
[0032] As illustrated more clearly in Figure 1, the hammer 1 comprises a plurality of discharge channels 31 to provide a fluid path to a medium. Petition 870260009089, dated 01 / 30 / 2026, page 29 / 80 16 / 22 discharge. The discharge channels are provided in a radially spaced arrangement around the hammer. A first part 32 of each discharge channel extends longitudinally within the wall 3 of the wear sleeve 2. As shown in the figures, the first part 32 of each discharge channel is internal to the wall 3 of the outer wear sleeve, meaning that it is disposed within the wall of the wear sleeve rather than being disposed within an inner surface of the wear sleeve itself. The first part 32 of each discharge channel has a first inlet 33 on an inner surface 4 of the outer wear sleeve. The first inlet 33 is positioned to exhaust air from an upper chamber 44 of the hammer. The first part of each discharge channel has a second inlet 35 on an inner surface 4 of the outer wear sleeve.As shown in Figures 1 and 5, the second inlet 35 is located ahead of the first inlet 33 for each discharge channel and is arranged to exhaust air from a lower chamber 45 of the hammer. The first part 32 of each discharge channel also comprises an outlet 34 at a forward end 9 of the outer wear sleeve wall.
[0033] A second part 36 of each discharge channel 31 extends longitudinally within the wall 12 of the drive ring 11. As shown in Figure 1, the second part 36 of each discharge channel is internal to the wall of the drive ring, that is, the second part of the discharge channel is disposed within and extends longitudinally through the wall of the wear sleeve instead of being disposed within the drive ring itself. A Petition 870260009089, dated 01 / 30 / 2026, page 30 / 80 17 / 22 The second part 36 of each discharge channel has an inlet 37 at a rear end of the drive ring, wherein each inlet 37 is arranged to receive the discharge medium from the outlet 34 of the first part of the corresponding discharge channel. The second part 36 of each discharge channel has an outlet 38 on an inner surface 39 of the drive ring. As shown in Figure 2, each outlet 38 is provided at one of the protrusions 16 on the drive ring. In other embodiments, the outlet of the second part of each discharge channel may be provided at a front end of the drive ring, for example, at the front end of one of the protrusions, or between two adjacent protrusions.
[0034] A third part 40 of each discharge channel extends through the head part 7 of the percussion drill 6 to a cutting face 41 of the drill. The third part 40 of each discharge channel has an inlet 42 in a head part of the percussion drill, wherein the inlet is arranged to receive the discharge medium from the outlet 38 of the second part of the corresponding discharge channel. The third part 40 of each discharge channel has an outlet 43 in a cutting face of the percussion drill.
[0035] In use, the upper chambers 44 and lower chambers 45 are alternately supplied with pressurized air. When the piston is at the top of its stroke, as shown in Figure 5, the upper chamber 44 is supplied with pressurized air. The inlets 33 of the discharge channels 31 are sealed by the piston 10. The piston is forced downwards to strike the percussion drill 6. Once the piston moves downwards (forwards) to the position shown in Figure 1, the Petition 870260009089, dated 01 / 30 / 2026, page 31 / 80 18 / 22 inlets 33 are opened to exhaust air from the upper chamber 44. As shown in Figure 1, when the piston is in the striking position, the lower chamber 45 is isolated from the discharge channels, thus preventing exposure of the lower chamber to ambient pressure.
[0036] When the piston is in the striking position, pressurized air is supplied to the lower chamber 45 via supply channels (not shown). As shown in Figure 1, the lower chamber is isolated from the discharge channels and is sealed by piston 10, drill bit 6 and aligner 29. As a result, piston 10 is raised and once the front end of the piston clears the second inlets 35 of the discharge channels, air is exhausted from the lower chamber to the cutting face of the drill bit. The cycle then repeats with air being supplied alternately to the upper and lower chambers to cause alternating movement of the piston within the wear sleeve.
[0037] A down-the-hole hammer 1 according to a second embodiment of the present invention is illustrated in Figures 6 to 8. The hammer 1 of the second embodiment is similar to that of the first embodiment, and identical reference numbers are used to refer to identical elements. The second embodiment differs from the first embodiment in that the drive ring 11 comprises a plurality of annular part segments 46, as shown in Figures 7 and 8. Each segment 46 is provided with three protrusions 16. In other embodiments, each segment may be provided with a greater or lesser number of protrusions. Instead of a drill retaining ring, each segment 46 is formed with a shoulder 47, so that when the ring of Petition 870260009089, dated 01 / 30 / 2026, page 32 / 80 19 / 22 drive 11 is fitted with a continuous drill retaining shoulder 48 which engages with the drill retaining shoulder 8 on the percussion drill to retain the drill bit in the hammer.
[0038] As shown in Figure 9, the drill retaining ring 21 of the embodiment shown in Figures 1 to 5 can be supplied as the two pieces or halves of the drill retaining ring part 21a, 21b. In alternative embodiments, the ring 21 can be divided into a larger number of parts. As can be seen in Figure 1 and as indicated in Figure 10A, the depth D of the holes 25 in the collar 22 of the drive ring 11 is greater than the height H of the drill retaining ring. This allows the percussion drill 6 to be removed from the hammer without removing the drive ring 11. This can be achieved by retracting the screws 30 from the holes 25 by a distance equal to or greater than the height H of the drill retaining ring parts, but less than the depth D of the holes.As shown in Figure 10B, the outer wear sleeve 2 can then be moved away from the percussion drill 6, for example, when lifting the hammer, thereby creating an annular space 47 between the front end 9 of the wear sleeve and the inner shoulder 24 of the drive ring. The screws 30 are still fitted into the holes 25 and thus the drive ring 11 is still retained on the hammer.
[0039] As shown in Figure 10C, as the hammer is raised further, the percussion drill bit 6 descends out of the hammer, so that the drill retaining part of the drill bit engages with halves 21a, 21b of the drill retaining ring 21. The mass of the drill bit causes the halves to move outward in a radial direction. Petition 870260009089, dated 01 / 30 / 2026, p. 33 / 80 20 / 22 into the annular space 47 such that they no longer retain the percussion drill bit in the hammer, as shown in Figure 10D. This allows the drill bit to be removed or replaced without removing the hammer drive ring. A new drill bit can be inserted and the drill retaining ring halves 21a, 21b returned to the drill retaining position by means of the pins 48, shown in Figure 11, extending through the drive ring 11 and arranged to fit into the halves 21a, 21b. In an alternative embodiment, an elastic O-ring can be provided around the drill retaining ring halves 21a, 21b to predispose the halves inwards such that they return to their original drill retaining position when the drill bit is removed. Once the new drill bit has been inserted, the hammer is reassembled by moving the wear sleeve towards the drill bit and fully inserting the screws into the holes.
[0040] A down-the-hole hammer according to an embodiment of a second aspect of the invention is illustrated in Figure 12. The hammer 1201 comprises an outer wear sleeve 2 and a percussion drill 6 having a head portion 7 and a drill retention shoulder 8 located at a forward end 9 of the outer wear sleeve. The hammer 1201 also comprises a sliding piston 10 mounted for reciprocating motion within the outer wear sleeve for striking the percussion drill.
[0041] The hammer further comprises a drive ring 11 having an annular collar 22 provided at a rear end 23 thereof, arranged to receive the Petition 870260009089, dated 01 / 30 / 2026, page 34 / 80 21 / 22 front end 9 of the wear sleeve such that the front end of the wear sleeve rests on an internal shoulder 24 of the drive ring. A plurality of internally threaded holes 25 is provided in a rear end 26 of the collar, and the rear end of the collar is arranged to be in contact with a front end 27 of a flange 18. A plurality of through holes 28 is provided in the flange. Each through hole corresponds to one of the plurality of holes in the collar. A screw 30 is inserted into each through hole 28 and screwed into the corresponding hole 25 in the collar to connect the drive ring to the wear sleeve and thus to the drive means of the percussion drilling tool. The clamping effect of this screwed arrangement also retains the drill retaining ring 21 in place between the drive ring 11 and an aligner 29.Keys 50 in the drive ring engage with complementary keys 51 in the percussion drill to transfer rotational drive to the drill.
[0042] As shown in Figure 9, the drill retaining ring 21 is provided as the two annular part halves of drill retaining ring 21a, 21b. In other embodiments, the ring may comprise a greater number of annular part pieces. The depth D of the holes 25 in the collar 22 of the drive ring is greater than the height H of the drill retaining parts such that the percussion drill is removable from the drilling tool by retracting the screws 30 from the holes 25 by a distance equal to or greater than the height of the drill retaining parts 21a, 21b, but less than the depth of the holes such that Petition 870260009089, dated 01 / 30 / 2026, p. 35 / 80 22 / 22 such that when the outer wear sleeve 2 is moved away from the percussion drill 6 an annular space is formed between the front end of the wear sleeve and the inner shoulder of the drive ring, to which the drill retaining parts are movable in an outward radial direction such that they no longer retain the percussion drill in the drilling tool. The percussion drill 6 can thus be removed from the hammer 1201 without removing the drive ring 11, in a manner similar to that described above with reference to Figures 10A to 10D.
[0043] The words comprise / comprising and the words having / including when used in this document with reference to the present invention are used to specify the presence of reported features, whole numbers, steps or components, but do not exclude the presence or addition of one or more other features, whole numbers, steps, components or groups thereof.
[0044] It is noted that certain features of the invention, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, several features of the invention which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable subcombination. Petition 870260009089, dated 01 / 30 / 2026, page 36 / 80
Claims
1 / 9 CLAIMS 1. Fluid-operated percussion drilling tool (1) comprising: an outer wear sleeve (2) comprising a substantially cylindrical wall (3) and having inner (4) and outer (5) surfaces; a percussion drill bit (6) having a head part (7) and a drill bit retaining part (8) and located at a forward end (9) of the outer wear sleeve; a sliding piston (10) mounted for reciprocating motion within the outer wear sleeve for striking the percussion drill bit; a drive ring (11) having a substantially cylindrical wall (12) and comprising connecting means (13) adapted for connecting the drive ring to drive means of the fluid-operated percussion drilling tool;at least one discharge channel (31) to provide a fluid path to the cutting face of the drill bit for a discharge medium, characterized in that a first part (32) of the at least one discharge channel extends longitudinally within the wall (3) of the wear sleeve (2), a second part (36) of the at least one discharge channel (31) extends longitudinally within the wall (12) of the drive ring and a third part (40) of the at least one discharge channel extends through the head part (7) of the percussion drill bit (6) to the cutting face (41) of the drill bit.
2. Fluid-operated percussion drilling tool according to claim 1, characterized by Petition 870260076047, dated 07 / 30 / 2026, page 11 / 28 2 / 9 in that the first part (32) of or of each discharge channel has a first inlet (33) on an inner surface (4) of the outer wear sleeve (2) and an outlet (34) on a forward end (9) of the outer wear sleeve wall.
3. Fluid-operated percussion drilling tool according to claim 2, characterized in that the first part (32) of or of each discharge channel has a second entry (35) on an inner surface (4) of the outer wear sleeve (2), wherein the second entry is in a different longitudinal position along the wear sleeve than the first entry (33).
4. Fluid-operated percussion drilling tool according to claim 3, characterized in that the second inlet (35) is located ahead of the first inlet (33).
5. Fluid-operated percussion drilling tool according to any one of claims 2 to 4, characterized in that the second part (36) of or of each discharge channel has an inlet (37) at a rear end of the drive ring and an outlet (38), wherein the inlet is arranged to receive the discharge medium from the outlet of the first part of the discharge channel.
6. Fluid-operated percussion drilling tool according to claim 5, characterized in that the outlet (38) of the second part of or of each discharge channel is provided on an inner surface (39) of the drive ring.
7. Percussion drilling tool operated by Petition 870260076047, dated 07 / 30 / 2026, page 12 / 28 3 / 9 fluid, according to claim 5, characterized in that the outlet (38) of the second part of or of each discharge channel is provided at a forward end of the drive ring.
8. Fluid-operated percussion drilling tool according to any one of claims 5 to 7, characterized in that the third part (40) of or of each discharge channel has an inlet (42) in a head part (7) of the percussion drill (6) and an outlet (43) in a cutting face (41) of the percussion drill, wherein the inlet is arranged to receive the discharge medium from the outlet of the second part of the discharge channel.
9. Fluid-operated percussion drilling tool, according to any of the preceding claims, characterized in that it further comprises fitting means (14) in the percussion drill (6) fitting with complementary fitting means (16) in the drive ring (11) by which the rotational drive of the drive ring can be transmitted to the percussion drill.
10. Fluid-operated percussion drilling tool according to claim 9, characterized in that the fitting means are provided in the head part (7) of the percussion drill.
11. Fluid-operated percussion drilling tool according to claim 10, characterized in that the fitting means in the head part of the percussion drill comprise a plurality of recesses (14) and the complementary fitting means in the drive ring comprise a corresponding plurality of protrusions (16) on a forward end (17) thereof, wherein each protrusion is received within a corresponding recess to transmit rotational drive from the drive ring to the percussion drill.
12. Fluid-operated percussion drilling tool according to claim 11, characterized in that the drive ring comprises a plurality of separable segments of annular drive teeth and each drive tooth segment comprises one or more of the plurality of protrusions.
13. Fluid-operated percussion drilling tool according to claim 11 or 12, characterized in that the second part of each discharge channel has an outlet (38) in one of the protrusions (16) on the drive ring.
14. Fluid-operated percussion drilling tool according to claim 11 or 12, characterized in that the second part of each discharge channel has an outlet (38) between two adjacent protrusions (16) on the drive ring.
15. Fluid-operated percussion drilling tool, according to any of the preceding claims, characterized in that it further comprises an annular flange (18) arranged around the outer wear sleeve (2) at a forward end (9) thereof.
16. Fluid-operated percussion drilling tool according to claim 15, characterized Petition 870260076047, dated 07 / 30 / 2026, page 14 / 28 5 / 9 by the fact that the flange is prevented from moving forward relative to the wear sleeve by the engagement of an internal shoulder (19) provided on the flange (18) with an external shoulder (20) provided on a forward end (9) of the wear sleeve (2).
17. Fluid-operated percussion drilling tool according to claim 15 or 16, characterized in that the drive ring connection means comprise an annular collar (22) provided at a rear end (23) of the drive ring (11), arranged to receive a front end (9) of the wear sleeve (2) such that a front end of the wear sleeve rests on an internal shoulder (24) of the drive ring.
18. Fluid-operated percussion drilling tool according to claim 17, characterized in that it further comprises a plurality of holes (25) provided in a rear end (26) of the collar (22), and the rear end of the collar is arranged to be in contact with a front end (27) of the flange (18).
19. Fluid-operated percussion drilling tool according to claim 18, characterized in that the flange (18) comprises a plurality of through holes (28) provided therein, and in that each through hole corresponds to one of the plurality of holes (25) in the collar, and in that each through hole and corresponding hole in the collar are configured to receive a fastener (30) for connecting the drive ring (11) to drive means of the percussion drilling tool. Petition 870260076047, dated 07 / 30 / 2026, p. 15 / 28 6 / 9 20. Fluid-operated percussion drilling tool (1) comprising: an outer wear sleeve (2) comprising a substantially cylindrical wall (3) and having inner (4) and outer (5) surfaces; a percussion drill bit (6) having a head part (7) and a drill bit retaining part (8) and located at a forward end (9) of the outer wear sleeve; a sliding piston (10) mounted for reciprocating motion within the outer wear sleeve for striking the percussion drill bit; a drive ring (11) having a substantially cylindrical wall (12) and comprising connecting means (13) adapted for connecting the drive ring to drive means of the fluid-operated percussion drilling tool;and characterized in that it further comprises an annular flange (18) arranged around the outer wear sleeve (2) at a forward end (9) thereof, wherein the flange comprises a plurality of through holes (28) provided therein and is prevented from moving forward relative to the wear sleeve by the fitting of an inner shoulder (19) provided in the flange with an outer shoulder (20) provided at a forward end (9) of the wear sleeve (2);and wherein the drive ring connection means comprise an annular collar (22) provided at a rear end (23) of the drive ring (11), the collar comprising a plurality of holes (25) provided at a rear end (26) thereof, in Petition 870260076047, dated 07 / 30 / 2026, p. 16 / 28 7 / 9 wherein each hole (25) corresponds to one of the plurality of through holes (28) in the flange, the collar arranged to receive a front end (9) of the wear sleeve in such a way that a front end of the wear sleeve rests on an inner shoulder (24) of the drive ring and the rear end (26) of the collar is arranged to be in contact with a front end (27) of the flange and wherein each through hole (28) and corresponding hole (25) in the collar (22) are configured to receive a fastener (30) for connecting the drive ring (11) to drive means of the percussion drilling tool.; 21. Fluid-operated percussion drilling tool according to claim 20, characterized in that it further comprises a drill retaining ring (21) arranged for fitting with the drill retaining part of the percussion drill to retain the percussion drill in the drilling tool, wherein the drill retaining ring is fastened between the drive ring (11) and an aligner (29) by fitting the fasteners with the drive ring.
22. Fluid-operated percussion drilling tool according to claim 21, characterized in that the drill retaining ring (21) is provided as a plurality of annular drill retaining part pieces (21a, 21b); and wherein the depth (D) of the holes in the collar (22) of the drive ring (11) is greater than the height (H) of the drill retaining parts such that the percussion drill is removable from the drilling tool by retracting the holders (30) from the holes (25) by a Petition 870260076047, dated 07 / 30 / 2026, page.17 / 28 8 / 9 distance equal to or greater than the height of the drill retaining parts, but less than the depth of the holes, such that when the outer wear sleeve is displaced away from the percussion drill, an annular space (47) is formed between the front end (9) of the wear sleeve and the inner shoulder (24) of the drive ring, to which the drill retaining parts are movable in an outward radial direction such that they no longer retain the percussion drill in the drilling tool.
23. Fluid-operated percussion drilling tool according to claim 22, characterized in that it further comprises an O-ring arranged around the drill retaining parts.
24. Fluid-operated percussion drilling tool according to claim 22, characterized in that it further comprises a plurality of pins (48) extending through the drive ring and arranged to fit into the drill retaining parts.
25. Method for removing a percussion drill bit (6) from a fluid-operated percussion drilling tool (1), as defined in claim 22, characterized in that it comprises: retracting the hole retainers (30) by a distance equal to or greater than the height (H) of the drill retaining parts, but less than the depth of the holes; displacing the outer wear sleeve (2) and the drive ring (11) away from each other to create an annular space (47) between the front end (9) of the wear sleeve and the inner shoulder (24) of the drive ring; and move the drilling tool (1) and the percussion drill bit (6) away from each other, such that the drill retaining part (8) of the percussion drill bit causes the drill retaining parts (21a, 21b) of the drill retaining ring (21) to move outward radially in the annular space.
26. Method according to claim 25, characterized in that the method is additionally for replacing the percussion drill bit, the method further comprising: inserting a percussion drill bit (6) into the distal end of the percussion drill tool (1); displacing the drill retaining parts (21a, 21b) of the drill retaining ring (21) in a radially inward direction by driving a plurality of pins (48) extending through the drive ring (11) and arranged to engage with the drill retaining parts; and displacing the outer wear sleeve (9) in the direction of the percussion drill bit (6) and reinserting the fasteners (30) into the holes (25). Petition 870260076047, dated 07 / 30 / 2026, p. 19 / 28