Patent US3756332A successfully refreshed from Google Patents.
US3756332A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disc type center cutter for a boring machine
Assignee: Robbins Co
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Filing: 1971-11-01
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Granted: 1973-09-04
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Expires: 1991-11-01
Abstract
Abstract A fixed shaft is mounted on the cutterhead to extend across the rotary axis of the cutterhead. A plurality of independently freely rotating disc cutter wheels are mounted on said shaft at different radial spacings from the cutterhead axis. The cutterhead carries additional disc cutters spaced radially outwardly from the center cutter assembly. All disc cutters include circumferential cutting edges which cut concentric kerfs in the rock at the tunnel face and sloping breaker surfaces on opposite sides of the cutting edge for crushing and dislodging the rock between the kerfs. The centermost disc cutter of the center cutter assembly includes a radially inwardly facing breaker surface which crushes and dislodges the material within the kerf cut by said centermost disc cutter. The disc cutter wheels have parallel radial side faces. The wheels are mounted for rotation by plain bearings or bushings which carry the radial loads. Washer-like plain radial bearings are provided outwardly of each of the side faces to carry the thrust loads. A seal ring presenting a radial face of hard material against the radial side face of the cutter wheel surrounds each thrust bearing. A ring of elastomeric material serves to cushion the seal member and urge it positively into contact with the side face of the cutter wheel.
Inventors
- 👤 C Crane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:03
CPC Classifications
E; E21; E21D; E21D9/00; E21D9/10; E21D9/1006; E21D9/104; E21B; E21B10/00; E21B10/08; E21B10/12; E21B10/22
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
133 words
In a rock boring machine including a cutterhead mounted for rotation about an axis, center cutter means comprising a disc cutter wheel having a circumferential cutting edge flanked by a pair of sloping rock breaker surfaces intersecting at the cutting edge, and means mounting said disc cutter wheel on said cutterhead with its cutting edge spaced radially close to said axis and oriented to cut a kerf concentrically surrounding said axis, with the radially inner rock breaker surface of such wheel being located close enough to said axis to effectively fracture all of the rock located radially inwardly of said kerf, said means comprising an elongated fixed shaft extending across the cutterhead and intersecting the axis of rotation of the cutterhead, and shaft support means on each side of said center cutter wheel.
Claim 2
Dependent Claim
133 words
In a rock boring machine including a cutterhead mounted for rotation about an axis, center cutter means comprising a disc cutter wheel having a circumferential cutting edge flanked by a pair of sloping rock breaker surfaces intersecting at the cutting edge, and means mounting said disc cutter wheel on said cutterhead with its cutting edge spaced radially close to said axis and oriented to cut a kerf concentrically surrounding said axis, with the radially inner rock breaker surface of such wheel being located close enough to said axis to effectively fracture all of the rock located radially inwardly of said kerf, said means comprising an elongated fixed shaft extending across the cutterhead and intersecting the axis of rotation of the cutterhead, and shaft support means on each side of said center cutter wheel.
Claim 3
Dependent Claim
56 words
The combination of claim 1, further comprising a plurality of additional disc cutter wheels mounted on the cutterhead aNd oriented to cut concentric kerfs surrounding the kerf cut by the inner cutter wheel, and each including a pair of sloping rock breaker surfaces flanking its cutting edge, said surfaces serving to fracture the rock between kerfs.
Claim 4
Dependent Claim
26 words
The combination of claim 1, wherein said shaft supports at least one additional disc cutter wheel which is independently mounted for free rotation about such shaft.
Claim 5
Dependent Claim
84 words
The combination of claim 3, wherein each said disc cutter wheel comprises a pair of parallel radial side faces, such cutter wheels are mounted for independent free rotation about the shaft by an annular sleeve type bearing, and an annular radial thrust seal contacts the radial inner portion of each cutter wheel side face, and a seal member concentrically surrounds each said thrust washer, each seal member having a radial seal face in sliding sealing contact with the side face of the cutter wheel.
Claim 6
Dependent Claim
46 words
The combination of claim 4, wherein each seal member is provided with an annular ring of elastomeric material between it and a portion of the mounting means, for cushioning the seal ring and axially urging it into contact with the side face of the cutter wheel.
Claim 7
Dependent Claim
178 words
In a rock boring machine including a cutterhead mounted for rotation about an axis, a center cutter assembly comprising: a fixed shaft extending across the axis of rotation of the cutterhead, a first disc cutter wheel mounted for free rotation about said shaft at a location radially outwardly from said axis of rotation, a second disc cutter wheel mounted for free rotation about said shaft at a location spaced on the opposite side of said axis of rotation and radially outwardly from said axis a further distance than said first disc cutter wheel, each of said disc cutter wheels comprising a circumferential cutting edge oriented to cut a kerf along a circular path surrounding the axis of rotation, and sloping rock breaker surfaces flanking said cutting edge, with the radially inward breaker surface of the first disc cutter wheel being spaced close enough to the axis of rotation to effectively fracture the center region rock located inside the kerf established by such disc cutter wheel, and shaft support means on each side of each said disc cutter wheel.
Claim 8
Dependent Claim
178 words
In a rock boring machine including a cutterhead mounted for rotation about an axis, a center cutter assembly comprising: a fixed shaft extending across the axis of rotation of the cutterhead, a first disc cutter wheel mounted for free rotation about said shaft at a location radially outwardly from said axis of rotation, a second disc cutter wheel mounted for free rotation about said shaft at a location spaced on the opposite side of said axis of rotation and radially outwardly from said axis a further distance than said first disc cutter wheel, each of said disc cutter wheels comprising a circumferential cutting edge oriented to cut a kerf along a circular path surrounding the axis of rotation, and sloping rock breaker surfaces flanking said cutting edge, with the radially inward breaker surface of the first disc cutter wheel being spaced close enough to the axis of rotation to effectively fracture the center region rock located inside the kerf established by such disc cutter wheel, and shaft support means on each side of each said disc cutter wheel.
Claim 9
Dependent Claim
64 words
The combination of claim 6, further comprising a third disc cutter wheel mounted for free rotation on said shaft radially outwardly of said first disc cutter wheel, said third disc cutter wheel being spaced radially outwardly from the axis of rotation a distance fruther than the second disc cutter wheel, and means supporting said shaft on each side of said third disc cutter wheel.
Claim 10
Dependent Claim
81 words
The combination of claim 7, further including a fourth disc cutter wheel and mounting means therefor situated laterally outwardly from an intermediate portion of said center cutter assembly, including a fixed shaft extending radially of the cutterhead and substantially at a right angle to the shaft of said center cutter assembly, said fourth disc cutter wheel being mounted for free rotation about said second shaft to form a kerf radially outwardly adjacent the kerf cut by the third disc cutter wheel.
Claim 11
Dependent Claim
103 words
The combination of claim 8, further comprising a fifth disc cutter wheel spaced laterally outwardly from said center cutter assembly on the side thereof opposite the fourth disc cutter wheel, and including a fixed shaft mounted on said cutterhead to extend radially of the cutterhead and substantially at a right angle to the axis of the center cutter assembly shaft and substantially coaxially with the shaft for the fourth disc cutter wheel, said fifth disc cutter wheel bieng mounted for free rotation about its shaft so as to cut a kerf radially outwardly adjacent the kerf cut by the fourth disc cutter wheel.
Claim 12
Dependent Claim
137 words
A rock cutting assembly comprising a fixed shaft, a disc cutting wheel mounted for free rotation on said shaft, said wheel including a pair of generally radial side faces, a circumferential cutting edge, and a pair of rock breaker surfaces flanking said cutting edge and intersecting the radial side faces of said wheel, mounting means for said shaft including a member disposed axially outwardly of each said radial side face, each said member including an annular groove therein opening towards its side face of the disc cutter wheel, a nonrotating seal member inside each said groove, and an elastomeric material serving to urge each seal member axially towards its radial face of the disc cutter wheel, said seal member including a radial seal face making sliding sealing contact with the radial face of the disc cutter wheel.
Claim 13
Dependent Claim
137 words
A rock cutting assembly comprising a fixed shaft, a disc cutting wheel mounted for free rotation on said shaft, said wheel including a pair of generally radial side faces, a circumferential cutting edge, and a pair of rock breaker surfaces flanking said cutting edge and intersecting the radial side faces of said wheel, mounting means for said shaft including a member disposed axially outwardly of each said radial side face, each said member including an annular groove therein opening towards its side face of the disc cutter wheel, a nonrotating seal member inside each said groove, and an elastomeric material serving to urge each seal member axially towards its radial face of the disc cutter wheel, said seal member including a radial seal face making sliding sealing contact with the radial face of the disc cutter wheel.
Claim 14
Dependent Claim
49 words
The rock cutter assembly of claim 10, comprising a sleeve type plain bearing mounting said disc cutter wheel for free rotation about the shaft, and an annular radial thrust bearing supported axially outwardly of each radial side face of the disc cutter wheel, radially inwardly of the seal members.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |