US4846631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gearbox for a rotary, mineral cutting head
Assignee: MINOVATION Ltd MULBERRY HOUSE CHEVET LANE SANDAL WAKEFIELD A CORP OF GREAT BRITAIN
•
Filing: 1987-09-03
•
Granted: 1989-07-11
•
Expires: 2007-09-03
Abstract
Abstract A gearbox for a rotary, mineral cutting head, comprises a casing housing speed reduction gearing and also a portion of a drive shaft supported by first and second, spaced-apart bearings, with at least one radially extending cylinder having a closed inner end and an open, outer end provided in said drive shaft and a reciprocable piston partially housed in said cylinder with a fluid seal between said piston and said cylinder; a variable volume, pressure-generating chamber defined between a radially inner end of said piston and a closed, inner end of its cylinder; a ring surrounding said drive shaft and having an inner profile and with a radially outer end of said piston in contact with said inner profile and with said piston.
Inventors
- 👤 George A. Parrott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:27
CPC Classifications
E; E21; E21C; E21C25/00; E21C25/60; E21C25/06; E21C25/10; E21C35/00; E21C35/22; E21C35/23
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
254 words
A gearbox comprising: a casing; speed reduction gearing contained in said casing; at least a portion of a drive shaft also contained in said casing said drive shaft having an axis of rotation; first and second bearings spaced apart along said axis; at least one radially extending cylinder having a closed inner end and an open, outer end being provided in said drive shaft; a reciprocable piston at least partially housed in said cylinder; a fluid seal between the external periphnery of said piston and said cylinder; a variable volume, pressure-generating chamber defined between a radially inner end of said piston and a closed inner end of its cylinder; a ring surrounding said drive shaft with an inner profile provided on said ring; a radially outer end of said piston being in contact, at least in a pumping mode, with said inner profile, such that upon rotation of said drive shaft, variations in radial distance of said inner profile from said drive shaft axis of rotation cause reciprocation of said piston, and a consequent pumping effect; at least one fluid transfer port communicating with said pressure-generating chamber; with said first and second bearings also absorbing loading from said piston and said ring; valve means to control fluid admission to, and delivery from, each of said pressure-generating chamber; and oil seals at the outsides of said first and second bearings between rotary and non-rotary parts of said gearbox to maintain separation between said fluid within said pressure generating chamber and lubricating oil of said gearbox.
Claim 2
Dependent Claim
254 words
A gearbox comprising: a casing; speed reduction gearing contained in said casing; at least a portion of a drive shaft also contained in said casing said drive shaft having an axis of rotation; first and second bearings spaced apart along said axis; at least one radially extending cylinder having a closed inner end and an open, outer end being provided in said drive shaft; a reciprocable piston at least partially housed in said cylinder; a fluid seal between the external periphnery of said piston and said cylinder; a variable volume, pressure-generating chamber defined between a radially inner end of said piston and a closed inner end of its cylinder; a ring surrounding said drive shaft with an inner profile provided on said ring; a radially outer end of said piston being in contact, at least in a pumping mode, with said inner profile, such that upon rotation of said drive shaft, variations in radial distance of said inner profile from said drive shaft axis of rotation cause reciprocation of said piston, and a consequent pumping effect; at least one fluid transfer port communicating with said pressure-generating chamber; with said first and second bearings also absorbing loading from said piston and said ring; valve means to control fluid admission to, and delivery from, each of said pressure-generating chamber; and oil seals at the outsides of said first and second bearings between rotary and non-rotary parts of said gearbox to maintain separation between said fluid within said pressure generating chamber and lubricating oil of said gearbox.
Claim 3
Dependent Claim
63 words
A gearbox as claimed in claim 1, of the epicyclic kind, comprising a sun gear rotatable about said drive shaft axis and in drivable engagement with a plurality of planet gears carried by a portion of said drive shaft serving as a carrier, with said planet gears rotatable about axes parallel to said sun gear axis, and in mesh with a stationary annulus.
Claim 4
Dependent Claim
23 words
A gearbox as claimed in claim 1, provided with a multiple number of said cylinders and pistons, located in a common diametral plane.
Claim 5
Dependent Claim
24 words
A gearbox as claimed in claim 1, wherein said valve means is a check valve, and one valve means per transfer port is employed.
Claim 6
Dependent Claim
33 words
A gearbox as defined in claim 1, in combination with a rotary, mineral cutting head, with said first and second bearings also serving to absorb loading imposed upon said cutting head during cutting.
Claim 7
Dependent Claim
30 words
A gearbox as claimed in claim 1, wherein said inner profile of said ring is circular, with said ring located eccentrically with respect to said drive shaft axis of rotation.
Claim 8
Dependent Claim
60 words
A gearbox as claimed in claim 1, wherein said ring is in the form of a bearing ring, with said inner profile provided by an inner annular face of an inner race part which is separated from an outer race part by a plurality of rollers, and said outer race part is located stationarily with respect to said drive shaft.
Claim 9
Dependent Claim
43 words
A gearbox as claimed in claim 1, wherein said ring is located concentrically with respect to said drive shaft axis of rotation, with said inner profile lobed, to constitute a cam track, said ring being located stationarily with respect to said drive shaft.
Claim 10
Dependent Claim
27 words
A gearbox as claimed in claim 8, wherein an outer end of said piston(s) is provided with a roller follower arrangement, for indirect engagement with said profile.
Claim 11
Dependent Claim
38 words
A gearbox as claimed in claim 1, wherein said fluid transfer port(s) serves for both the conveying of low pressure fluid to its associated pressure-generating chamber, and the delivery of high pressure fluid from its associated pressure-generating chamber.
Claim 12
Dependent Claim
35 words
A gearbox as claimed in claim 10, wherein said fluid transfer port(s) extends axially along said drive shaft and terminates at one end at a radial connection port in communication with its associated pressure-generating chamber.
References Cited (Backward Citations)
US1910581A
Cited
US2461121A
Cited
US3204561A
Cited
US4049318A
Cited
US4212497A
Cited
US4331064A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-10 | 1993-01-09 | 1993-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-10 | 1997-01-09 | 1997-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-10 | 2001-01-09 | 2001-07-11 | $7700.00 | Window Closed / Lapsed |