GB2055925A - Rotary Cutter Heads - Google Patents
Rotary Cutter Heads Download PDFInfo
- Publication number
- GB2055925A GB2055925A GB7927996A GB7927996A GB2055925A GB 2055925 A GB2055925 A GB 2055925A GB 7927996 A GB7927996 A GB 7927996A GB 7927996 A GB7927996 A GB 7927996A GB 2055925 A GB2055925 A GB 2055925A
- Authority
- GB
- United Kingdom
- Prior art keywords
- cutting
- cutter head
- tool
- head
- hub
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/10—Making by using boring or cutting machines
- E21D9/1006—Making by using boring or cutting machines with rotary cutting tools
- E21D9/104—Cutting tool fixtures
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C25/00—Cutting machines, i.e. for making slits approximately parallel or perpendicular to the seam
- E21C25/06—Machines slitting solely by one or more cutting rods or cutting drums which rotate, move through the seam, and may or may not reciprocate
- E21C25/10—Rods; Drums
Abstract
A rotary cutter head for a mining machine comprises a plurality of cutting tools (1 to 10) arranged in at least one sequential cutting pattern, the tools in the sequential cutting pattern being arranged to cut at different radial displacements from the rotational axis (22) of the cutter head. <IMAGE>
Description
SPECIFICATION
Rotary Cutter Heads
This invention relates to rotary cutter heads for mining machines.
In particular, the present invention relates to a rotary cutter head having a plurality of rock or mineral cutting tools mounted in at least one sequential cutting pattern so that, in use, as the rotary cutter head rotates the cutting tools in any particular cutting pattern cut rock or mineral in a preselected order.
In a prior known rotary cutter head the cutting tools in any particular cutting pattern are all mounted radially displaced from a radially outer surface of a hub of the cutter head so that in use as the rotating cutter head is advanced into the rock or mineral face each cutting tool penetrates into the rock or mineral face further than its predecessor in the same cutting pattern. Figure 1 is an incomplete diagrammatic illustration representing a downwardly directed horizontal view through the rotational axis of the cutter head and illustrates a typical cutting sequence for at least some of the cutting tools mounted on a rotary cutter head in two cutting patterns.One cutting pattern is formed by the cutting tools 1,2, 3, 4 and 5 and the other by-the cutting tools 6, 7, 8, 9 and 1 0. Figure 2 shows that the cutting tools in the first mentioned cutting pattern are angularly spaced around the rotational axis 1 2 of the cutter head, the angular spacing between a cutting tool and its neighbours substantially being 720. In Figure 2 the cutting tools 1 to 5 are shown mounted on similar stands 1 3 radiating from a radially outer surface of a substantially cylindrical hub 1 5 provided with a bore (not shown) for drivably engaging a drive shaft of a mining machine.Figure 1 indicates that the cutting tools in a cutting pattern are spaced from one another across the web of the cutter head in a direction substantially parallel to the rotational axis of the cutter head. In Figures 1 and 2 the direction of cutter drum advance is indicated by arrowXsubstantially normal to the rotational axis and the direction of cutter head rotation about the rotational axis of the cutter head is indicated by arrow Y.
The advance of the cutter head into the rock or mineral face 14 during one revolution of the cutter head is indicated in Figure 1 by a. Typically when the cutter head is cutting relatively hard rock a can be about 25 mm.
Cutting tool 1 is mounted on the cutter head so as to cut rock or mineral adjacent to a free face 1 6 formed by the cutter head on its previous traverse along the rock or mineral face, the tool 1 being arranged to be the leading cutting tool of the cutting pattern comprising the cutting tools 1 to 5. As seen in Figure 1 the cutting tool 1 penetrates into the rock or mineral face to an extent indicated by reference numeral 1 in the
Figure, the rock or mineral breaking to the free face 1 6. As the cutter head rotates the next cutting tool of that particular cutting pattern to penetrate the rock or mineral face is tool 2.As seen in Figure 1 tool 2 penetrates further into the rock or mineral face that its predecessor tool 1, the increase in tool penetration arising due to the advance of the cutter head by an approximate distance of a/S. Tool 2 is followed by cutting tool 3, then tool 4 and finally tool 5, each pick penetrating into the rock or mineral face further than its predecessor and the rock or mineral cut by each tool breaking towards the cut profile formed by its predecessor.
Upon the completion of one revolution the cutting tool 1 once again penetrates into the rock or mineral face as indicated by 1' in Figure 1.
Similarly, this tool is followed by the remaining cutting tools forming that particular cutting pattern, the associated tool penetrations being indicated by 2', 3', 4t and 5' respectively.
A similar cutting sequence is followed by the cutting tools 6 to 10 of the other cutting pattern the tools 8, 9, 10, 6 and 7 being at the same angular displacements as the tools 1, 2, 3, 4 and 5, respectively.
The cutting tools of the two cutting patterns are arranged on the cutter head such that a substantially balanced cutting force is exerted on the cutter head throughout cutting. For example, the cutting tools 1 and 8 are arranged to cut substantially simultaneously with the same penetration so their resultant reaction on the cutter head tends to be balanced.
One disadvantage of such a prior known cutter head is the cutting tool spacing for tools in the same cutting pattern in a direction parallel to the rotational axis of the cutter head is relatively large. Experience has indicated that for optimum cutting efficiency a cutting tool spacing to tool penetration ratio of approximately 2:1 should be employed.
For a given rate of cutter head advance and a given rotational speed the effective cutting tool penetration is dependant upon the number of cutting patterns provided on the cutter head. For example, in the cutter head associated with
Figures 1 and 2 and having two over lapping cutting patterns, and a rate of advance of 25 mm per revolution of the cutter head the penetration of each cutting tool is approximately 12.5 mm.
Consequently, if a optimum cutting tool spacing to penetration ratio is sought then the cutting tool spacing for tool in the same cutting pattern must be approximately 25 mm i.e. the tool spacing on the cutter head must be approximately 12.5 mm.
It will be appreciated that in order to achieve such a desired cutting tool spacing it would be necessary to provide an unrealistically large number of cutting tools on the cutter head.
An object of the present invention is to provide an improved cutter head tending to enable the optimum cutting tool spacing to penetration ratio to be obtained or approached.
According to the present invention a rotary cutter head for a mining machine comprises a hub defining a formation for enabling the cutter head to be rotated and presenting a radially outward facing surface, a plurality of cutting tools angularly spaced around the hub and spaced from one another in a direction substantially parallel to the rotational axis of the cutter head, at least some of the cutting tools being arranged in a sequential cutting pattern and being arranged to cut at different radial displacements from the outward facing surface of the hub, respectively.
Preferably, at least a portion of the hub is cylindrical.
Conveniently, at least a portion of the radially
outward facing surface is tapered.
Preferably, the leading cutting tool in a particular cutting pattern cuts at a preselected
radial displacement from the outward facing hub surface and the following cutting tools in the particular sequential cutting pattern are arranged to cut progressively nearer to said surface.
Conveniently, the reduction in the radial
displacement from the outward facing hub surface of the trailing cutting tool of a particular
cutting pattern compared to the leading cutting
tool of the cutting pattern is proportional to the
desired advance of the cutter head during the time the cutting tools of that particular cutting
pattern are in cutting engagement with the rock
or mineral face.
Advantageously, the cutting tools 6f a
particular cutting pattern substantially are
angularly spaced around one complete revolution
of the cutter head, the difference in the radial
displacement between the leading and trailing
cutting tools substantially being equal to the
desired advance of the cutter head per revolution
of the cutter head.
Conveniently, the-cutting tools are arranged in
a plurality of cutting patterns.
By way of example only, two embodiments of the present invention now will be illustrated with
reference to Figures 3 to 6 of the accompanying
drawings, in which:
Figure 3 diagrammatically illustrates the
cutting profile obtained with a first embodiment
of cutter head constructed in accordance with the
present invention, the illustration represents a
downwardly directed horizontal or sectional view
taken through the rotational axis of the cutter
head;
Figure 4 is an incomplete diagrammatic end
view of a cutter head comprising a plurality of
cutting tools at least some of which are arranged
to produce the sequential cutting profile
illustrated in Figure 3;;
Figure 5 diagrammatically illustrates the
sequential cutting profile obtained with a second
embodiment of cutter head constructed in
accordance with the present invention, the
illustration represents a downwardly directed
horizontal sectional view taken through the
rotational axis of the cutter head; and
Figure 6 is an incomplete diagrammatic end
view of a cutter head comprising a plurality of
cutting tools at least some of which are arranged
to produce the sequential cutting profile
illustrated in Figure 5.
Figures 3 and 4 relate to a rotary cutter head for a rock or mineral mining machine, for example, a roadheader type machine for excavating rock or mineral to extend a mine roadway, the cutter head being mounted as a forwardly directed boom pivotally supported on a mobile base, the cutter head being arranged to rotate about an axis either parallel to, or transverse to, the axis of the boom. Alternatively, the rotary cutter head may be mounted, for example, on a shearer type machine for traversing to and fro along a longwall mineral face, the cutter head either being mounted directly onto the machine body or on an arm pivotally or fixedly mounted on the machine body.
The rotary cutter head is arranged to rotate about an axis of rotation 22 (see Figure 4) and to be advanced into the rock or mineral face at a rate advance of a mm per revolution of the cutter head, for example, in a typical example for cutting relatively hard rock the rate of advance is 25 mm per revolution of the cutter head. The direction of advance which substantially is normal to the rotational axis is indicated by arrow X and the direction of cutter head rotation is indicated by arrow Y.
The cutter head comprises ten cutting tools 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 arranged in a single cutting pattern and mounted on stands 21,23, 27,29,31,33,35,37,39 and 41, respectively.
Figure 4 shows that the cutting tools are angularly spaced around the rotational axis 22 of the cutter head, the angular spacing between one cutting tools and its neighbours being substantially 360 so that the single cutting pattern substantially is arranged over one complete revolution of the cutter head. In Figure 4, the cutting tools 1 to 10 are shown to be mounted on stands of progressively decreasing height so that the cutting margins of the tools arranged to follow in sequence on the cutting pattern are at progressively decreasing displacements from the rotational axis 22 of the cutter head and from a radially outer cylindrical surface of a cylindrical stand-supporting hub 25 from which the stands radiate. The hub 25 is provided with an axial bore (not shown) drivably engageable on a driven shaft of the mining machine. Alternatively, the axial bore drivably engages a formation drivably engageable on the drive shaft, the formation assisting removal of the cutter head from the shaft for repair or replacement.
Figure 3 indicates that the cutting tools in the single cutting pattern are spaced from one another across the web of the cutter head in a direction substantially parallel to the rotational axis of the cutter head.
Cutting tool 1 is mounted on the cutter head so as to cut rock or mineral adjacent to a free face 26 formed by the cutter head on its previous traverse along the working rock or mineral face, the tool 1 being arranged to be the leading cutting tool of the cutting pattern. As seen in Figure 3 the cutting tool 1 penetrates into the rock or mineral face to an extent indicated by reference numeral 1 in the Figure, the rock or mineral breaking to the free face 26. As the cutter head rotates through substantially 360 the next cutting tool in the cutting sequence, i.e. cutting tool 2, penetrates into the rock or mineral face as illustrated by reference numeral 2 of Figure 3.Although the cutter head has advanced into the working rock or mineral face by an amount equal to a/i 0 mm as the stand 23 is a/i 0 mm shorter than stand 21 and thereby the radial displacement of tool 2 is a/i 0 mm less than that of tool 1 , the cutting tool 2 penetrates into the working face to the same extent as the previous cutting tool 1. Hence as seen in Figure 3, the penetration of the cutting tool 2 is equal to the penetration of cutting tool 1.
Upon the cutter head rotating through 720 the next cutting tool in the cutting sequence, i.e.
cutting tool 3, penetrates into the working rock or mineral face as illustrated by reference numeral 3 of Figure 3. Although the cutter head as advanced into the working rock or mineral face by an amount equal to a/5 mm as the stand 27 is a/5 mm shorter than the stand 21 and thereby the radial displacement of the tool 3 is a/5 mm less than that of tool 1, the cutting tool 3 penetrates into the working face only to the same extent as the previous cutting tools 1 and 2. Hence as seen in Figure 3, the penetration of the cutting tool 3 is equal to the penetration of the prior cutting tools
land 2.
A similar procedure occurs in sequence for each of the following cutting tools 4, 5, 6, 7, 8, 9 and 10, and as the associated stands 29, 31, 33, 35, 37, 39 and 41 are reduced in height by 3a/1 0 mm, 2a/5 mm, a/2 mm, 2a/3 mm, 7a/10 mm, 4a/5 mm, and 9a/10 mm respectively, radial displacements are similarly less than that of tool
1, the penetration of these cutting tools is equal to that of the previous cutting tools in the cutting pattern.
Hence, as illustrated in Figure 3 the penetration of each cutting tool lies along side the penetration of its neighbours. As the cutting tools 1 to 10 substantially are arranged around one complete revolution of the cutter head, the radial displacement of the trailing tool 10 substantially is less than that of the leading tool 1 by an amount substantially equal to the desired advance per revolution of the cutter head, i.e.
approximately a mm.
Upon the rotary cutting head completing one revolution the cutting tool 1 is reintroduced into the working face to start off a new cutting sequence, the second penetration of cutting tool 1 being indicated by reference numeral 1' in
Figure 3. After cutting tool 1 has further penetrated into the working face by a penetration a mm all the other cutting tools follow in sequence their penetrations being represented by the reference numerals 2', 3', 4', 5', 6', 7', 8', 9' and 10', respectively.
This cutting pattern has an advantage over the prior known cutting pattern illustrated with reference to Figures 1 and 2, that the cutting tool spacing in a direction across the web of the cutter head i.e. substantially parallel to the axis of rotation, is halved. This is achieved even though the number of cutting tools in both embodiments is the same, i.e. ten.
Thus, the optimum 2:1 ratio of cutting tool spacing to penetration is achieved by having a cutting tool penetration of a and a spacing of 2a.
This is a more realistic arrangement than that discussed earlier with reference to prior known embodiment.
A further advantage of the cutter head as described with reference to Figures 3 and 4 is that the angular positions of the cutting tools can be varied while at the same time maintaining a derived cutting pattern by adjusting the cutting height of the associated cutting tools, the cutting height being the distance from the cutting margin of the tool to the rotational axis of the cutter head or to the radially outer surface presented by the hub. This alteration would permit more cutting tools to be accommodated on the cutter head or ancillary equipment such as water jets to be fitted. Alternatively, the cutting tools could be redistributed to give optimum cutting conditions for sumping into the rock face in a direction substantially parallel to the rotational axis or to achieve balanced cutting or improved rock debris removal.
Cutter heads for carrying out the present invention would be designed to give a particular desired advance per revolution of the cutter head.
Hence in some embodiments a control system would be included to ensure the cutter head was advanced at the desired rate.
Figures 5 and 6 relate to a rotary cutter head for a rock or mineral mining machine, for example, a roadheader type machine for excavating rock or mineral to extend a mine roadway, the cutter head being mounted on a forwardly directed boom pivotally supported on a mobile base, the cutter head having its rotational axis 52 (see
Figure 6) coaxial with the axis of the boom.
The rotary cutter head is arranged to rotate about the axis of rotation 52 and to be advanced into the rock or mineral working face at a desired rate of advance of a mm per revolution of the cutter head, for example, in a typical example cutting relatively hard rock the rate of advance substantially is 25 mm per revolution of the cutter head. The direction of advance which substantially is normal to the rotational axis is indicated by arrow X and the direction of cutter head rotation is indicated by arrow Y.
The cutter head comprises a plurality of cutting tools at least ten of which 1,2,3,4,5,6,7,8,9 and 10 are arranged in two non-overlapping sequential cutting patterns and mounted on stands 53, 54, 55, 56, 57, 58, 59, 60,61 and 62,respectively. Figure 6 shows that the ten cutting tools are angularly spaced around the rotational axis 52 of the cutter head, the angular spacing between one cutting tool and its neighbours on the same cutting pattern being substantially 720.
Each cutting pattern substantially is arranged around one complete revolution of the cutter head. In Figure 6 the cutting tools 1 to 10 are shown to be mounted on stands radiating outwards from a frusto-conical hub 65 presenting a radially outward facing surface which is tapered or inclined to the axis of the rotation of the cutter head, the radial displacement of the cutting tools from the tapering or inclined radially cutter surface of the conical hub i.e. the distance from the cutting tip or margin of each tool to said surface differing for each cutting tool. Typical values of the actual radial displacement will be given later in this specification.The radial displacement associated with each particular cutting pattern progressively decreases so the cutting margins of the tools arranged to follow in sequence on a particular cutting pattern are at prdgressively decreasing radial displacement from the tapering or inclined, radially outer hub surface.
The stands radiate from the tapered or inclined portion of the frusto-conical hub 65 provided with an axial bore (not shown) drivably engageable on a drive shaft of the mining machine. The end face 68 of the hub is provided with cutting tools (not shown) enabling the cutter head to cut in a direction generally parallel to the axis 52 to enable the cutter head to sump into the rock or mineral face on the recommencement of a cutting cycle.
Figure 5 indicates that the cutting tools in the two cutting patterns are spaced from one another across the web of the cutter head in a direction substantially parallel to the rotational axis of the cutter head.
Cutting tool 1 is mounted on the cutter head so as to cut rock or mineral adjacent to a free face 66 formed by the cutter head on its previous traverse along the working rock or mineral face, the tool 1 being arranged to be the leading cutting tool of one of the two cutting patterns. Cutting tool 2 is approximately mid way along the web of the cutter head and is arranged to be the leading cutting tool of the other cutting pattern. As seen in Figure 6 the cutting tool 2 is angularly spaced from cutting tool 1 by 360 and its radial displacement from the radially outer hub surface is 3a/5 mm less than the radial displacement of tool 1 from said surface.The reduction in radial displacement is made up of a factor a/2 mm as tool 2 lags approximately one half a cutting increment behind tool 1 plus a factor of a/10 mm as tool 2 angulariy lags one tenth of a revolution behind tool 1 as seen in Figure 6.
Upon the cutter head revolving 720 from the start of cutting, tool 3 penetrates the rock or mineral face 64 by an amount equal to the penetration of the leading tool 1 of that particular cutting pattern. In that tool 3 may have the same penetration as tool 1 the radial displacement of tool 3 from the radially outer hub surface is approximately a/5 mm less than that of tool 1.
The next tool to cut is tool 4 which in order to have the same penetration as the leading tool 2 must have its radial displacement reduced by 4a/5 mm compared to that of tool 1 or by a/5 mm compared to that of tool 2.
The cutting procedure continues in a similar matter to that previously described, the following cutting tools 5, 7 and 9 of the first mentioned cutting pattern having their radial displacements from the hub surface as compared to tool 1 reduced by 2a/5 mm, 3a/5 mm and 4a/5 mm, respectively, and the cutting tools 6, 8 and 10 of the other cutting pattern having then radial displacements from the hub surface as compared to tool 1 reduced by 4a/5 mm, 9a/1 0 mm and a mm, respectively.
Thus as shown in Figure 5 all the cutting tools penetrate the rock or mineral face to the same extent.
Upon the cutter head completing one revolution the whole of the two cutting patterns are repeated on the second revolution, the tool penetrations being indicated by reference numerals 1 3', 5', 7' and 9' and 2', 4', 6', 8' and 10'.
In other embodiments of the invention the cutting tools on the cutter head may comprise more than two cutting patterns which may or may not overlap.
Variation in the displacement of the tool cutting margin relatively to the radially outer hub surface can be achieved by having stands or plafforms of the desired height formed on the hub or by having plates or fillets of a desired thickness secured to the hub surface, tool holders for the cutting tools being mounted on the stands, plafforms, plates or fillets.
In other embodiments of tha invention the cutter head includes a hub of partially cylindrical and partially conical form.
In other embodiments the radially outward facing surface of the hub is curved in a direction parallel to the rotational axis of the cutter head.
Claims (9)
1. A rotary cutter head for a mining machine comprising a hub defining a formation for enabling the cutter head to be rotated and presenting a radially outward facing surface, a plurality of cutting tools angularly spaced around the hub and spaced from one another in a direction substantially parallel to the rotational axis of the cutter head, at least some of the cutting tools being arranged in a sequential cutting pattern and being arranged to cut at different radial displacements from the outward facing surface of the hub, respectively,
2. A head as claimed in claim 1, in which at least a portion of the hub is cylindrical.
3. A head as claimed in claim 1 or 2, in which at least a portion of the radially outward facing surface is tapered or inclined relatively to the axis of rotation of the cutter head.
4. A head as claimed in any one of the preceding claims, in which the leading cutting tobl in a particular cutting pattern cuts at a preselected radial displacement from the radially outward facing hub surface and the following cutting tools in the particular sequential cutting pattern are arranged to cut progressively nearer to said hub surface.
5. A head as claimed in claim 4, in which the reduction in the radial displacement from said hub surface of the trailing cutting tool of a particular cutting pattern compared to the leading cutting tool of the cutting pattern is proportional to the desired advance of the cutter head during the time the cutting tools of that particular cutting pattern are in cutting engagement with the rock or mineral face.
6. A head as claimed in claim 5, in which the cutting tools of a particular cutting pattern substantially are angularly spaced around one complete revolution of the cutter head, the difference in the radial displacement between the leading and trailing cutting tools substantially being equal to the desired advance of the cutter head per revolution of the cutter head.
7. A head as claimed in any one of the preceding claims, in which the cutting tools are arranged in a plurality of cutting patterns.
8. A head as claimed in any one of the preceding claims, in which the leading cutting tool of at least one sequential cutting pattern is arranged to cut adjacent to a free rock or mineral face formed by the cutter head on a previous traverse.
9. A rotary cutter head for a mining machine, substantially as described herein with reference to
Figures 3 and 4 or 5 and 6 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7927996A GB2055925A (en) | 1979-08-10 | 1979-08-10 | Rotary Cutter Heads |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7927996A GB2055925A (en) | 1979-08-10 | 1979-08-10 | Rotary Cutter Heads |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2055925A true GB2055925A (en) | 1981-03-11 |
Family
ID=10507140
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7927996A Withdrawn GB2055925A (en) | 1979-08-10 | 1979-08-10 | Rotary Cutter Heads |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2055925A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1604097A1 (en) * | 2003-03-14 | 2005-12-14 | Age Mining Services Pty Ltd | A mining lacing pattern |
-
1979
- 1979-08-10 GB GB7927996A patent/GB2055925A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1604097A1 (en) * | 2003-03-14 | 2005-12-14 | Age Mining Services Pty Ltd | A mining lacing pattern |
| EP1604097A4 (en) * | 2003-03-14 | 2006-06-14 | Age Mining Services Pty Ltd | A mining lacing pattern |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3865202A (en) | Water jet drill bit | |
| RU2571471C2 (en) | Heading machine | |
| US4185873A (en) | Machine for mechanically advancing clean cut underground mining galleries of various profiles | |
| CN110821510A (en) | High-pressure water jet edge cutter and combined rock breaking and trapped-freeing TBM cutter head and method thereof | |
| CN210685990U (en) | Hydraulic-mechanical combined rock breaking TBM cutter head and TBM device thereof | |
| CA2661476A1 (en) | Method and apparatus for the milling cutting of materials | |
| US3139148A (en) | Rotary boring head having roller cutter disks | |
| US3477762A (en) | Mining machine and method | |
| US4169629A (en) | Tunneling machine with plural adjustable arms carrying single cutter | |
| US4371210A (en) | Freely rotatable pick bit holder on rotary driven member and method | |
| US3958832A (en) | Drum mining head with cutter pattern | |
| US2550202A (en) | Rock cutting apparatus | |
| US3075591A (en) | Tunnel boring machines | |
| Hekimoglu et al. | Theoretical and practical aspects of circumferential pick spacing on boom tunnelling machine cutting heads | |
| GB2055925A (en) | Rotary Cutter Heads | |
| US3064958A (en) | Drilling, core cutting and dislodging head for mining machines | |
| US3307880A (en) | Cutter bit mounting for ripper type miner | |
| CN209557002U (en) | Cutter head of shield machine with down-the-hold drill bit | |
| US4025116A (en) | Method of operating a constant depth linear cutting head on a retrofitted continuous mining machine | |
| CA1038854A (en) | Earth auger drill | |
| CN211777446U (en) | Open-type soft rock heading machine advance support system | |
| CN114135309A (en) | Rectangular section excavation cutter head and heading machine | |
| US4393949A (en) | Rock boring apparatus | |
| CN110905542A (en) | TBM cutter head suitable for flexible arm heading machine and excavation method thereof | |
| CN112832798A (en) | Block-controlled cutter head of push bench |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |