阅读说明：本技术 带流体供应管道的旋转切割头 (Rotary cutting head with fluid supply conduit ) 是由 拉尔夫·格里夫 于 2017-04-20 设计创作，主要内容包括：一种用于切割机的旋转切割头(15),其包括位于该头部的周边部分处的多个喷嘴(29),用以将流体射流引导到位于刀盘(14)上的切割球齿中的所选出的切割球齿。所述喷嘴(29)被定位地安装在所述头部上,以便在切割期间将流体射流引导到所述球齿中的所选出的径向最外面的球齿。(a rotary cutting head (15) for a cutting machine includes a plurality of nozzles (29) at a peripheral portion of the head to direct fluid jets to selected ones of cutting buttons located on an impeller (14). The nozzle (29) is positionally mounted on the head so as to direct a jet of fluid to selected radially outermost ones of the buttons during cutting.)

1. A rotary cutting head (15) for a cutter (10), comprising:

A rotatable support frame (23), the support frame (23) having a radially inner region and a radially peripheral portion (20), and being rotatably coupled to a rotary drive unit (55);

A plurality of cutter units (13) mounted at or towards the peripheral portion (20), each unit (13) having a cutter disc (14) rotatably mounted on a hub (25), a radially outer portion of each cutter disc (14) being configured to abrade rock and create cut grooves therein by rotation of the cutter disc (14);

Each impeller head (14) being rotatable relative to the rotatable support frame (23) by means of a respective cutter hub (25);

A plurality of fluid supply conduits (36), said fluid supply conduits (36) extending at said support frame (23) and being disposed to be in fluid communication with a first set of nozzles (29) to deliver fluid to said impeller (14);

The nozzles (29) being mounted on the support frame (23) such that the impeller (14) is independently rotatable relative to the nozzles (29); and is

The nozzles (29) are positionally mounted to direct fluid jets to the following regions (28) of the impeller (14): the zone (28) is located radially outside the peripheral portion (20) of the support frame (23), and the zone (28) defines a radially outermost periphery of the cutting head (15).

2. The cutting head according to claim 1, further comprising a fluid flow director (60) to direct a fluid flow to only selected ones of the nozzles (29) at the peripheral portion (20) of the support frame (23).

3. The cutting head as claimed in claim 2, the selected nozzles (29) comprising nozzles (29) positioned on the support frame (23) in angular segments of 100 ° to 200 °, 130 ° to 170 °, or 140 ° to 160 °.

4. The cutting head of claim 3, the fluid flow director (60) comprising a disc located at the radially inner region (21) of the support frame (23), the disc having a plurality of holes and/or slots (63) extending through angular segments of the disc in the range of 100 ° to 200 °, 130 ° to 170 °, or 140 ° to 160 °.

5. The cutting head according to any one of the preceding claims, further comprising a fluid flow interrupter to provide an intermittent fluid flow to the nozzle (29).

6. the cutting head according to any one of the preceding claims, wherein the fluid supply conduit (36) extends internally within the support frame (23) in a radially outward direction from the inner region (21) to the peripheral portion (20).

7. The cutting head according to any one of the preceding claims, further comprising a second set of nozzles (33) in fluid communication with the fluid supply conduit (36) and mounted on the support frame (23) at respective locations to direct fluid jets onto the hub (25).

8. the cutting head of claim 7, wherein the first and second sets of nozzles (29, 33) are mounted on respective shrouds (40) at the peripheral portion (20) of the support frame (23), the shrouds (40) being positioned in a circumferential direction between the respective hubs (25).

9. The cutting head of claim 8, wherein each nozzle (29) of the first set of nozzles is positioned at a location radially outward of each nozzle (33) of the second set of nozzles at each shroud (40).

10. The cutting head according to claim 8 or 9, wherein each shield (40) is removably mountable on the support frame (23).

11. The cutting head according to any one of the preceding claims, wherein each cutterhead (14) cannot be independently rotatably driven relative to the drive unit (55) which drives the rotation of the support frame (23).

12. the cutting head of claim 11, wherein each cutterhead (14) is configured to: each cutterhead (14) is rotatably driven only by rotation of the drive unit (55) via the support frame (23).

13. The cutting head according to any one of the preceding claims, further comprising a gearbox (22) arrangement with a drive shaft by which the support frame (23) is rotatably mounted and driven.

14. The cutting head according to any one of the preceding claims, having 5 to 20 cutter units (13) mounted at the peripheral portion (20).

15. The cutting head according to any one of the preceding claims, further comprising a plurality of cutting buttons (19) mounted at the radially outer portion of each impeller (14), the nozzle (29) being positionally mounted to direct the fluid jet to a selected one of the buttons (19) of the impeller (14), the selected button (19) being located radially outwardly of the peripheral portion (20) of the support frame (23) and defining the radially outermost periphery of the cutting head (15).

16. the cutting head of any one of the preceding claims, wherein the axis of rotation (26) of each respective cutterhead (14) is substantially aligned with the axis of rotation (24) of the support frame (23).

17. Cutting machine (10), the cutting machine (10) comprising at least one cutting head (15) according to any one of the preceding claims.

18. The cutting machine of claim 17, which is an undercut mining machine (10).

Technical Field

The present invention relates to a rotary cutting head for a cutting machine, and in particular, but not exclusively, to a cutting head adapted to provide fluid streams to a set of nozzles mounted at a peripheral portion of the cutting head, thereby generating fluid jets to a peripheral cutting region of the head.

background

A variety of different types of cutters have been developed for many different applications of rock cutting in a mine environment, such as cutting roadways, tunnels, subterranean roadways, and the like. Undercutters are generally suitable for cutting hard rock by using the undercutting principle, in which a rotatable cutter is pressed against the rock and dragged against it to create a groove that helps overcome the tensile strength of the rock.

Typically, an undercutter includes a set of roller cutters mounted at the cutting head, which may be raised upwardly in an undercut mode. Each roller cutter comprises a cutter ring or disc rotatably mounted on a support shaft which is rotatable about its central axis. Cutter rings are wear parts and need to be replaced regularly as they become worn in aggressive contact with hard rock.

Existing mining and excavating machines are typically provided with a water spray mechanism that continuously or intermittently supplies water towards the cutting area to firstly cool the cutting teeth and secondly to help suppress dust. US3,563,324 discloses a rotary cutting machine having a plurality of cutting teeth mounted at the periphery of the cutter body. A plurality of atomizing nozzles are mounted on the cutter body to direct a jet of water toward the cutting teeth as the cutting proceeds through the rock. Similarly, US 4,296,824 discloses a set of nozzles mounted towards the cutting region of the cutting head to provide a continuous stream to the cutting region which entrains swarf back away from the cutting region. US 4,721,341 discloses a cutting head with an internally fed spray device in which water is fed at high pressure to a set of nozzles located near the cutting teeth.

However, the existing arrangement is disadvantageous for a number of reasons. In particular, accelerated wear and inefficient cutting of the cutting teeth often results due to a non-optimal fluid (i.e., water) supply to the cutting teeth and the rock region being cut. In fact, cutting teeth (alternatively referred to as cutting picks or buttons) in addition to cutting new rock also grind the rock that has been cut off into smaller fines, which is undesirable. In addition, existing arrangements often involve complex fluid supplies, necessitating multiple sealed moving interfaces, valves, etc., which increases the risk of repair and maintenance, as well as fluid leaks. In addition, the nozzles of the prior arrangements can be susceptible to blockage by dust and debris generated during cutting. Thus, there is a need for a cutting head that addresses these problems.

disclosure of Invention

It is an object of the present invention to provide a rotary cutting head for a cutting machine which is suitable for an efficient cutting action and which minimizes accelerated wear of the cutting teeth (cutting picks or buttons) due to undesired regrinding of rock which has been cut. A particular object of the present invention is to provide and direct a fluid flow into the path of the cutting edge or tooth in order to provide cleaning or cleaning of the cutting area in addition to cooling of the cutting edge or tooth.

Another object of the present invention is to provide a simple, robust and reliable system for supplying (cleaning/cooling) fluid to the cutting area of a rotating cutting head in order to minimize the risk of repair, maintenance and fluid leakage. Yet another object is to minimize the number of component parts of the cutting head, in particular of the fluid supply system, to effectively reduce the need for and reliance on seals and valves at one or the moving interfaces.

Another object is to provide a fluid supply arrangement in which the nozzles at the cutting zone are effective to provide an intermittently selective supply of fluid to the cutting edges or teeth, while being positionally arranged to minimize the risk of nozzle clogging or damage during cutting. Another particular object of the present invention is to provide a rotary cutting head having a plurality of cutting units, which are easy to replace, either by themselves or as component parts thereof, for maintenance and repair, while minimizing the damage to any sealing interface.

The above object is achieved by a rotary drill bit in which a rotatable support frame mounts a plurality of peripheral cutter units (each cutter unit having a cutter disc optionally carrying cutting buttons) and has at least a first set of nozzles positionally mounted on the support frame adjacent a respective one of the cutter units for directing fluid jets to a radially outer region of the respective cutter disc (which is located radially outwardly of a peripheral portion of the support frame), the radially outer region defining the radially outermost periphery of the cutting head. In particular, at least the nozzles of the first set of nozzles are positioned to direct fluid jets into the rotational path of the selected impeller, in particular into the region of the cut-out grooves (formed into the rock by the cutting action of the head) directly at the region of the radially outermost cutting portion (selected portion) of the impeller effective to cut the rock. Such fluid jets are primarily effective at flushing fines from around those areas of the cutting zone (i.e., the cutting edge or button) that are effective, so as to avoid regrinding of the cut rock, and thereby maximize cutting efficiency and minimize button wear. By positioning the nozzle on the rotatable support frame instead of on the cutting unit, in particular the cutting disc, abrasive contact of the nozzle with the rock is better prevented during cutting. In addition, the fluid supply path (through the internal conduit) does not extend through the independently rotatable cutting discs, thus minimizing the number of sealed moving interfaces (which form part of the fluid supply path within the rotatable support frame). Furthermore, the rotary cutting head of the present invention minimizes the need for seals, gaskets, etc. to provide a simple, reliable and robust construction. The rotary cutting head of the invention is therefore suitable for minimizing maintenance and service, while reducing the risk of fluid leakage. It will be appreciated that the nozzles in the first set of nozzles also effectively provide cooling to the cutting edges or buttons which is advantageous in minimising the operating temperature of the impeller and extending its operational useful life.

The rotary cutting head of the present invention is also adapted to provide selective fluid supply to selected parts of the cutter units, since not all cutter units are supplied with fluid at any one time, and only cutter units having active (i.e. cutting) cutting discs receive fluid. In addition, by specific positioning of the nozzles, the present invention directs fluid jets to only selected portions or regions of the cutting edges or buttons (at the selected cutting disk) to further optimize the volume of fluid delivered to the cutting region and to further increase the efficiency of the cutting process and the fluid cleaning and cooling processes.

In addition, the rotary cutting head of the present invention is adapted to provide an intermittent fluid supply through a fluid delivery arrangement comprising a conduit, slot, aperture or hole, which minimizes the need for a sealed interface (between moving parts of the rotary cutting head).

According to a first aspect of the present invention, there is provided a rotary cutting head for a cutting machine, comprising: a rotatable support frame having a radially inner region and a radially peripheral portion and rotatably coupled to the rotary drive unit; a plurality of cutter units mounted at or towards the peripheral portion, each unit having a cutter disc rotatably mounted on a cutter hub, a radially outer portion of each cutter disc being configured to abrade rock and produce cut grooves therein by rotation of the cutter disc; each cutterhead is rotatable relative to the rotatable support frame by each respective hub; a plurality of fluid supply conduits extending at the support frame and disposed in fluid communication with the first set of nozzles to deliver fluid to the impeller; the nozzles are mounted on the support frame such that the cutter head is independently rotatable relative to the nozzles; and the nozzles are positionally mounted to direct fluid jets to the following regions of the impeller: the zone is located radially outwardly of the peripheral portion of the support frame and defines a radially outermost periphery of the cutting head.

Optionally, the cutting head further comprises a fluid flow director to direct fluid flow to only selected ones of said nozzles at the peripheral portion of the support frame. Optionally, the fluid flow director is configured to provide a fluid flow to a selected nozzle, wherein the selected nozzle comprises a nozzle positioned on the support frame in an angular segment of 100 ° to 200 °, 130 ° to 170 °, or 140 ° to 160 °. This arrangement is advantageous to minimize the fluid volume for cleaning and cooling functions at the cutting area and to avoid overflow of the cutting area.

Optionally, the fluid flow director comprises a disc located at a radially inner region of the support frame, the disc having a plurality of holes and/or slots extending through an angular segment of the disc in the range 100 ° to 200 °, 130 ° to 170 °, or 140 ° to 160 °. This arrangement is superior to alternative valve-based arrangements that require multiple sealing interfaces. Thus, the inventive arrangement is beneficial in minimizing the number of component parts and providing a reliable assembly that is convenient to manufacture, install and maintain.

Optionally, the cutting head includes a fluid flow interrupter to provide an intermittent fluid flow to the nozzle. Optionally, the fluid flow interrupter comprises a disc located at a radially inner region of the support frame. Preferably, the interrupter is configured to manipulate the fluid flow to provide a pulsed fluid flow to the nozzle according to a predetermined timing interval.

Preferably, the fluid supply conduit extends internally within the support frame in a radially outward direction from the inner region to the peripheral portion. Preferably, the entire length of the fluid supply conduit is mounted within the cutting head. Optionally, the conduit comprises a hole, channel or duct formed as a bore extending within the solid component. Alternatively, the fluid supply conduit may comprise a pipe section, hose or other supply conduit mounted internally within the cutting head between the outer surfaces of the cutting head. This arrangement is advantageous to avoid damage to the supply conduit during cutting when the cutter is capable of operating in a restricted environment where contact with rock or other equipment or machinery may damage the supply conduit.

preferably, the cutting head further comprises a second set of nozzles in fluid communication with the fluid supply conduit and mounted on the support frame at respective locations to direct fluid jets onto the hub. This arrangement facilitates providing a flow of cooling fluid to the hub, thereby effectively cooling the internal components of the cutter unit, including, inter alia, oil, grease, bearings, etc.

Optionally, the first and second sets of nozzles are mounted on respective shrouds located at the peripheral portion of the support frame, the respective shrouds being disposed in the circumferential direction between the respective hubs. Optionally, each nozzle of the first set of nozzles is disposed at a position radially outward of each nozzle of the second set of nozzles at each shroud. This arrangement is advantageous in minimizing the length of the spray produced by the nozzle when delivered to the cutting edge or button (in the forward direction) and the hub (in the rearward direction). The present invention is therefore advantageous to maximize the efficiency of use of cleaning and cooling fluids and to avoid waste and overflow of cutting areas.

Optionally, each shroud is removably mounted on the support frame. Thus, if cleaning or other maintenance of the nozzles is required, each shroud can be conveniently detached and reattached to the support frame without damaging the remaining components of the cutting unit and cutting head.

Alternatively, each cutterhead cannot be independently rotatably driven relative to a drive unit that drives rotation of the support frame. Preferably, each cutterhead is configured to be rotatably driven by rotation of the drive unit only via the support frame. Thus, the cutting head of the present invention is beneficial in providing an efficient cutting action while minimizing the weight of the drive assembly, the cutter, and the maintenance and service of the cutting head. Preferably, the cutting head further comprises a gearbox arrangement having a drive shaft by which the support frame is rotatably mounted and driven.

Alternatively, the cutting head may comprise 5 to 20 cutter units mounted at the peripheral portion. Preferably each cutter unit is identical, including a uniform cutter head and hub.

Alternatively, the cutting head may include a plurality of cutting buttons mounted radially outwardly of each impeller, the nozzles being positionally mounted to direct fluid jets to selected ones of the buttons of the impeller located radially outwardly of the peripheral portion of the support frame, the buttons defining a radially outermost periphery of the cutting head. Preferably, the cutting buttons comprise a first material and the impeller comprises a second material, the material of the cutting buttons being harder than the material of the impeller.

optionally, the axis of rotation of each respective cutterhead is substantially aligned with the axis of rotation of the support frame. Preferably, each axis of rotation of each cutterhead is aligned substantially parallel to the axis of rotation of the support frame. Optionally, each axis of rotation of each cutterhead is aligned to be inclined radially outwardly from the axis of rotation of the support frame by an angle in the range of 1 to 15 °.

according to another aspect of the present invention, there is provided a cutting machine comprising at least one cutting head as claimed herein. Optionally, the cutter is an undercut miner, a continuous miner, an electric miner, and/or a miner having one, two, three, four or more cutting heads mounted at a distal end of a boom or arm capable of pivotal movement relative to a body or chassis of the machine. Optionally, the cutter may include a fluid reservoir, a fluid pump, a supply hose, and a valve to provide a fluid source to the cutting head.

Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a mobile undercut mining machine suitable for forming tunnels and subterranean roadways having a pair of front mounted pivoting cutting arms each mounting a rotating cutting head in accordance with an aspect of the present invention;

FIG. 2 is an underside view of one of the rotary cutting heads of FIG. 1 with selected components removed for illustration purposes, with a plurality of cutter units mounted at a peripheral portion of a rotatable support frame of the head, in accordance with an embodiment of the present invention;

FIG. 3 is a side elevational view of the cutting head of FIG. 2;

FIG. 4 is a lower perspective view of the rotary cutting head of FIG. 2;

FIG. 5 is an enlarged front view of selected ones of the cutter units of the cutting head of FIG. 2, wherein each unit includes a hub mounted independently rotatable cutterhead;

FIG. 6 is an enlarged rear view of selected cutting units of the cutting head of FIG. 2;

FIG. 7 is a cross-sectional view A-A of the rotary cutting head of FIG. 2 having an internal fluid supply arrangement to deliver cleaning/cooling fluid to the cutting discs in accordance with an embodiment of the present invention;

Figure 8 is a perspective view of a shroud located adjacent the cutting discs of the rotary head of figure 2, the shroud being fitted with first and second nozzles, respectively, to direct fluid jets onto the areas of the cutting discs and the support hub of the rotary head of figure 2;

FIG. 9 is a B-B cross-sectional view of the shroud of FIG. 8;

FIG. 10 is a front end view of the shroud of FIG. 8;

FIG. 11 is a rear end view of the shroud of FIG. 8; and

FIG. 12 is a plan view of a fluid director disk mountable at a radially inner region of the rotary cutting head of FIG. 2 to provide a selective supply of fluid to the cutting disk.

Detailed Description

A fluid (e.g., water) supply system according to the present invention is capable of delivering fluid to a cutting area of a rotary cutting head that is mountable to a variety of different types of cutting or mining machines. A particular embodiment of a rotary cutting head according to the invention is described with reference to an undercut mining machine for forming tunnels and subterranean roadways as a plurality of rotary heads gyrate laterally outward during forward cutting and are raised in an up and down direction. Rotary cutting heads are particularly well suited for delivering fluid to the cutting area of the head in order to increase cutting efficiency and reduce the rate of wear of the cutting edges or teeth formed at the peripheral portion of the cutting head.

Referring to fig. 1, a cutter 10 is configured to cut into rock in a mining environment to create a roadway, underground roadway, or the like, in order to form an underground mine network. The machine 10 is configured to operate in an undercut mode in which a plurality of rotatable roller cutter units 13 may be forced into the rock to form a groove or channel and then pivoted vertically upwardly to overcome the lesser tension immediately above the channel and break the rock. Thus, the cutter 10 is optimized to advance into rock using less force and energy than is typically required with conventional compression type cutters utilizing a cutting bit or pick mounted on a rotatable head.

Machine 10 includes a main frame 11a (or chassis) to which is mounted a sled 11b that is slidable forward and rearward along a front region of sled 11 a. A pair of support arms 12 are mounted to a forward region of the sled 11b and are configured with members that pivot independently through a generally horizontal pivot axis and a generally vertical pivot axis. A respective rotary cutting head 15 is mounted at the distal end of each arm 12 and is raisable in a vertical plane (up and down) and swivelable laterally (from side to side) in a horizontal plane by rotation about respective horizontal and vertical pivot axes. Each cutting head 15 mounts a plurality of cutter units 13, each unit 13 rotatably mounting a respective cutter disc 14 (also referred to as a roller cutter or cutting ring). It should be appreciated that the machine 10 also includes additional components associated with conventional undercutting apparatus, including, inter alia, motors, jacking legs, tracks, etc. The sideways pivotal movement of each arm 12 is provided by selective actuation of a first pair of externally mounted hydraulic cylinders 16, 17 and an internally mounted hydraulic cylinder 18, wherein each of the three cylinders is configured to control one of the two arms by linear extension and retraction of the piston shaft, as will be appreciated.

referring to fig. 2-4, each rotary cutting head 15 may be considered to be a wheel or disc having a radially inner region 21 and a radially outer peripheral portion generally indicated by reference numeral 20, when viewed in plan (or at a cross-section perpendicular to the axis of rotation 24 of the head 15). The peripheral portion 20 is generally circular about an axis 24. Each head 15 includes a support frame, generally indicated by reference numeral 23, which represents the body of the head 15. The support frame 23 according to the specific embodiment is a multi-component support structure comprising, for example, a series of panels, plates, posts, components and attachment elements (i.e. bolts and/or screws) that are formed together as a unitary body, thereby supporting the cutter unit 13 and withstanding the significant loading forces encountered at the head 15 during cutting.

As shown in fig. 2 and 4, the cutter units 13 are mounted at the peripheral portion 20 of the support frame 23 to generally define a ring of cutter units 13 extending about the axis 24. The cutter unit 13 is mounted at the peripheral portion 20 of the frame 23 such that the outer region of each impeller 14 extends radially beyond the peripheral portion 20. Thus, the diameter (or radius) of each head 15 is defined in part by the radially outermost portion of each impeller 14. In particular, each cutter head 14 carries a plurality of cutting buttons 19 (alternatively referred to as cutting picks or teeth) formed of a highly abrasive material, as is well known to those skilled in the art. The buttons 19 project radially outwardly from the radially outer or perimeter of each impeller 14. Thus, the total area indicated at 28 of each impeller 14 (and/or selected ones of the buttons 19) projects radially beyond the peripheral portion 20 of the support frame 23. It is this region 28 (and the selected buttons 19) which represents the effective cutting portion of each cutter unit 13.

It will be appreciated that each impeller 14 is mounted at a respective cutter hub 25, which cutter hub 25 represents the main component of each cutter unit 13. Each hub 25 includes an internally mounted bearing to permit free rotation of each impeller 14 about an axis of rotation 26, the axis of rotation 26 extending longitudinally through each generally cylindrical hub 25. Each cutterhead 14 is not positively or power driven at each hub 25, but rotates about axis 26 (of each respective cutter unit 13) and central axis 24 (of the respective cutting head 15) via powered/driven rotation of head 15 by drive unit 55 and gearbox 22 mounted on machine 10, particularly at each arm 12. That is, each head 15 is configured to rotate about axis 24 in direction R1 to cause a corresponding rotation in direction R2 of each impeller 14 pressed into contact with the rock during cutting. A region 28 (i.e., the selected cutting button 19) of each impeller 14 extends radially beyond the radially outermost peripheral surface 27 of the head 15, which region 28 represents the "effective" cutting region and button to provide a cutting action at any particular time period as each impeller rotates about each respective axis 26, 24 in the directions R2 and R1.

The peripheral portion 20 of each head 15 is defined by a plurality of shrouds shown separately in fig. 8 to 11. Each shroud 40 includes a generally "hammerhead" -shaped main plate 42 with a mounting flange 41 extending laterally from the main plate 42, the mounting flange 41 having through holes 43 to receive attachment bolts to mount each shroud 40 on the head support frame 23. The shroud 40 represents the radially outermost component of each head 15 and is positioned in the circumferential direction between each respective cutter unit 13 so as to at least partially envelope or nest on the adjacent cutter unit 13 at a location immediately behind each impeller 14. In particular, the "hammerhead" -shaped end of each plate 42 is located in the axial direction (of axis 26) between the impeller 14 and the hub 25, so that the laterally outward region 42a of a single plate 42 is located immediately behind the impellers 14 of two adjacent cutter units 13. The end surface of the plate 42 extending between the regions 42a represents the radially outermost surface 27 of the head 15 at the head peripheral portion 20.

The recess 30 is recessed into the first forward facing planar surface 31 of the plate 42. The first nozzle 29 is mounted inside the plate 42 such that the spray tip of the nozzle 29 is positioned at the recess 30. Thus, as fluid is supplied to the nozzles 29, a jet of fluid can be directed forwardly from the nozzles 29 and outwardly from the recess 30 onto a portion of the respective impeller 14. A corresponding recess 34 is formed in the second rearwardly facing planar surface 32 of the plate 42, with the surface 32 oriented to face the cutter hub 25. The second nozzle 33 is mounted in the plate 42 so as to have a spray tip emerging in the recess 34 so as to be able to generate a jet of fluid in the rearward direction and outwards from the plate 42. The forward facing first recess 30 and the first nozzle 29 are positioned to be aligned along a direction (represented by line 52) transverse to the longitudinal axis 51 of the plate 42 at an angle in the range of 75 ° to 85 °. Thus, each first nozzle 29 is oriented to direct a fluid jet only onto the zone 28 (selected buttons 19) located at the radially outermost zone of the head 15. In addition, a nozzle 29 is positioned adjacent each impeller 14 to direct a jet of fluid onto a selected button portion 28 as each impeller 14 rotates in the direction R2. That is, it can be said that the jet from each nozzle 29 flows in a clockwise direction, while each impeller 14 is configured to rotate in a counterclockwise direction. With the head 15 positioned against the rock during cutting, each nozzle 29 directs a fluid jet into a formed groove cut into the rock by the selected button portion 28, and in particular into the clearance space within the formed groove. This is beneficial for substantially flushing the cut grooves and removing rock pieces and fines to avoid grinding and regrinding the cut material. Thus, the cutting efficiency of the inventive arrangement is improved. The location and configuration of each first nozzle 29 also provides additional cooling of the buttons 19 and peripheral edge of each impeller 14 during cutting. This, together with the flushing of the cut rock and fines, minimizes wear of the buttons 19 and cutter disc 14 in order to prolong their service life. In the direction of the head axis 24 (and the corresponding cutter unit axis 26), each nozzle 29 is positioned slightly axially rearward relative to each impeller 14 and the button 19 in the selected section 28. In this way, the nozzle 29 and recess 30 are further oriented transverse to the head axis 24 (and corresponding cutter unit axis 26) to direct the fluid jet axially forward onto the button 19 in the selected portion 28.

each second nozzle 33 and corresponding second recess 34 are aligned in a direction indicated by a line 58, the line 58 extending perpendicular to the major length or axis 51 of the plate 42. That is, each second nozzle 33 is aligned transverse to each first nozzle 29 at each plate 42, with the angle between the respective nozzles 29, 33 (defined by direction lines 52, 58, respectively) being in the range of 5 to 15 °. Each second nozzle 33 and the respective recess 34 are aligned in the direction of the head axis 24 and cutter unit axis 26 to face generally rearwardly at the plate surface 32. Thus, the fluid jet generated from each nozzle 33 is directed rearwardly from the surface 32 and onto the cutter hub 25. Thus, each hub 25 is provided with a cooling fluid supply. This arrangement facilitates cooling of oil and grease within each hub 25, which in turn provides controlled cooling of the internal hub components (i.e., bearings, etc.).

The fluid supply path to each of the first and second nozzles 29, 33 will now be described with reference to fig. 7 to 12. Referring first to FIG. 7, the bit support frame 23 generally includes a forward facing annular face 37 and a rearward facing annular face 38. A central hub 35 is mounted at the radially inner portion 21 of the head 15 to represent the inner frame portion of the head 15. The peripheral frame assembly 59 provides a radially outer region on which the cutter unit 13 and the shroud 40 are each mounted. Each head 15 includes an inner conduit extending radially between inner hub 35 and outer assembly 59. Specifically, a central supply conduit 57 (shown schematically) provides a means of transferring fluid from the source reservoir into the head 15. Referring to fig. 7, in conjunction with fig. 12, the distributor disk 60 is mounted on the hub 35, centered on the axis 24. The disk 60 includes a series of discrete holes or slots 63 that extend an angular distance toward the perimeter 62 of the disk 60. According to a particular embodiment, disk 60 includes eight slots extending between first endmost slot 63a and second endmost slot 63 b. The angle alpha between each end slot 63a, 63b is in the range of 140 deg. to 160 deg.. The disc 60 is positioned adjacent the central supply conduit 57 by a central boss assembly 61 mounted at the inner hub 35 so that fluid can flow from the supply conduit 57 through the slot 63 and into the conduit 36 via the port 45. The boss assembly 61 comprises a series of annular discs, plates and seals to securely mount the disc 60 and provide a fluid tight seal for the transfer of fluid into the conduit 36 (within the support frame 23).

Referring again to fig. 7, hub 35 includes a plurality of feed conduits, generally indicated at 36, extending radially from hub 35 to an outer assembly 59. According to a particular embodiment, each head 15 comprises a number of ducts 36 corresponding to the number of cutter units 13, which number is 12 according to the present embodiment. Each feed conduit 36 includes a radially inner receiving port 45 that interfaces with a respective disc slot 63 to allow fluid from the central supply conduit 57 to be supplied into the feed conduit 36. The fluid then flows generally radially outward through the feed conduit segments 36a, 36b, 36c, and 36 e. The feed conduit 36 also includes various plugs 36f, 36d as needed for manufacturing convenience. A feed supply of fluid (feed supply of fluid) flows from the head periphery assembly 59 at the supply port 46.

referring to fig. 8-11, each shroud 40 includes a fluid delivery port 44 disposed at the rearward facing planar surface 32. A delivery conduit 48 extends axially within the plate 42, centered on an axis 51 between the port 44 and a pair of outlet ports 49, 50. A first outlet port 49 is provided in fluid communication with the second nozzle 33 and a second outlet port 50 is provided in fluid communication with the first nozzle 29, wherein the ports 49, 50 are positioned towards one end of the conduit 48 and the delivery port 44 is positioned towards the opposite end. Thus, fluid can be delivered to the head central hub 35 and then flow radially outward through the conduits 36 (via the distribution disk 60) and into each shroud 40 to each respective nozzle 29, 33. Due to the angular arrangement of the disc slots 63, only selected ones of the cutter units 13 are supplied with fluid at any one time as the head 15 rotates in the direction R1. Thus, the selected one of the first and second nozzles 29, 33 is effective to generate a respective fluid jet on the selected hobbing section 28 of the button 19 and cutter hub 25 used at a particular moment in time when cutting rock. In particular, the active cutter units 13 and the respective first and second nozzles 29, 33 comprise only those cutter units 13 which are arranged at the same respective angular distance α with respect to the dispenser slot 63.

According to aspects of the present disclosure, machine 10 and/or each head 15 may also include a fluid flow interrupter configured to provide intermittent fluid flow to nozzles 29, 33. Such an interrupter may be embodied as a specially configured disc mounted at the central boss instead of disc 60 or in addition to disc 60. The distributor disk 60 (and optionally also the fluid flow interrupter disk) is beneficial to provide efficient fluid use to only selected ones of the cutter units 13.

The above embodiments are described with reference to each cutter disc 14 having cutting buttons 19. According to further embodiments, each cutterhead 14 includes a radially outer peripheral edge region (without the need for additional cutting buttons 19) adapted to abrade the particular configuration of rock. According to such an embodiment, the first nozzle 29 is configured to direct a jet of fluid to the cutting edge of each impeller 14.