US3857449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for precisely thrusting pipes into the ground
Assignee: CO KOGANE
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Filing: 1973-07-05
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Granted: 1974-12-31
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Expires: 1993-07-05
Abstract
Abstract Herein disclosed is an improved apparatus for precisely thrusting pipes into the ground along a predetermined straight guide line. The apparatus includes a guide tube coaxially inserted in the pipe and actuated for proceeding and rotation, and an augar coaxially attached to the front end of the guide tube for excavating the front soil. In the apparatus, a laser beam source is used for generating a laser beam as the guide line which is normally running forward on the axis of the guide. This laser beam is reflected on a parallel reflector which is disposed at a relatively front portion of the guide tube in a manner to have its critical optical path coincident with the axis of the guide tube. In the apparatus, a displacement detecting device is also provided for detecting actual displacement of the common axis of the auger and the guide tube from the laser beam guide line in terms of optical displacement of the reflected backward laser beam from the forward laser beam. To this optical displacement is responsive a displacement correcting mechanism, which is interposed between relatively front portions both of the pipe being thrusted and the guide tube, so that the guide tube may be deflected relative to the pipe in the radial direction to reduce the actual displacement.
Inventors
- 👤 Y Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:49
CPC Classifications
E; E21; E21D; E21D9/00; E21D9/005; E21B; E21B7/00; E21B7/003; E21B7/005; E21B7/04; E21B7/046
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
322 words
An apparatus for precisely thrusting a pipe into the ground along a predetermined straight guide line, comprising: a straight guide tube normally substantially coaxially inserted in the pipe and having its foremost end extending therefrom, said guide tube being axially and rotationally movable relative to the pipe; auger means coaxially removably attached to the foremost end of said guide tube for excavating the front soil when rotated and thrusted forward together with said guide tube; a parallel reflector mounted in a relatively front portion of said guide tube in the vicinity of said auger means and having a critical optical path coincident with the axis of said auger means, said parallel reflector having such optical characteristics as to have reflected light rays follow said critical optical path, when incident light rays follow the same, and as to produce reflected light rays in parallel with incident light rays which have missed said critical optical path; a highly directive light source disposed on a rear extension of the axis of said guide tube for normally emitting as the guide line a highly directive light beam in the forward direction along said critical optical path; displacement detecting means for detecting displacement, if any abnormally, of the common axis of said auger means and said guide tube from the guide line in terms of displacement of the backward highly directive light beam, which is reflected on said parallel reflector, from the forward highly directive light beam which is emitted from said light source; and displacement correcting means interposed between the relatively front portion of said guide tube and a corresponding front portion of the pipe and responsive to the displacement of the highly directive light beam for deflecting said guide tube relative to the pipe in the direction to reduce the lastmentioned displacement substantially to zero, so that the course of said guide tube and accordingly of the pipe may follow precisely in the guide line.
Claim 2
Independent Claim
322 words
An apparatus for precisely thrusting a pipe into the ground along a predetermined straight guide line, comprising: a straight guide tube normally substantially coaxially inserted in the pipe and having its foremost end extending therefrom, said guide tube being axially and rotationally movable relative to the pipe; auger means coaxially removably attached to the foremost end of said guide tube for excavating the front soil when rotated and thrusted forward together with said guide tube; a parallel reflector mounted in a relatively front portion of said guide tube in the vicinity of said auger means and having a critical optical path coincident with the axis of said auger means, said parallel reflector having such optical characteristics as to have reflected light rays follow said critical optical path, when incident light rays follow the same, and as to produce reflected light rays in parallel with incident light rays which have missed said critical optical path; a highly directive light source disposed on a rear extension of the axis of said guide tube for normally emitting as the guide line a highly directive light beam in the forward direction along said critical optical path; displacement detecting means for detecting displacement, if any abnormally, of the common axis of said auger means and said guide tube from the guide line in terms of displacement of the backward highly directive light beam, which is reflected on said parallel reflector, from the forward highly directive light beam which is emitted from said light source; and displacement correcting means interposed between the relatively front portion of said guide tube and a corresponding front portion of the pipe and responsive to the displacement of the highly directive light beam for deflecting said guide tube relative to the pipe in the direction to reduce the lastmentioned displacement substantially to zero, so that the course of said guide tube and accordingly of the pipe may follow precisely in the guide line.
Claim 3
Dependent Claim
30 words
An apparatus according to claim 1, wherein said parallel reflector includes a cube corner having its apex lie in the common axis of said auger means and said guide tube.
Claim 4
Dependent Claim
24 words
An apparatus according to claim 1, wherein said light source includes a laser beam generator for generating a laser beam when it is energized.
Claim 5
Dependent Claim
53 words
An apparatus according to claim 1, further comprising a screw conveyor mounted on the outer wall of the remaining portion of said guide tube in slidable contact with the corresponding inner wall of the pipe for conveying the excavated soil in the backward direction when it is rotated together with said guide tube.
Claim 6
Dependent Claim
49 words
An apparatus according to claim 1, wherein said displacement detecting means includes an optical plate disposed midway of an optical path between said light source and said parallel reflector and having a central transmissive portion sized and positioned to allow the forward highly directive light beam to pass therethrough.
Claim 7
Dependent Claim
120 words
An apparatus according to claim 1, wherein said displacement correcting means includes a plurality of cylinders mounted on the outer wall of the relatively front portion of said guide tube and spaced angularly from each other, a plurality of pistons having their inner ends hermetically received in said cylinders and their outer ends made in sliding engagement with the inner wall of the corresponding front portion of the pipe, actuating means having fluid communication with each of said cylinders for actuating the same radially oUtwardly extend said pistons so that said guide tube may be deflected relative to the pipe when said actuating means is energized, and control means responsive to the last-mentioned displacement for selectively energizing said actuating means.
Claim 8
Dependent Claim
96 words
An apparatus according to claim 1, further comprising a plurality of supporting mechanisms mounted on the outer wall of the remaining portion of said guide tube and each including a bearing rotatably carried on said guide tube and a plurality of axially slender foot members radially outwardly extending from said bearing and angularly spaced from each other, said foot members having their radial extensions made in irrotatable but axially slidable engagement with the inner wall of the corresponding remaining portion of the pipe for rigidly supporting the pipe so as to preventing flexure of the same.
Claim 9
Dependent Claim
101 words
An apparatus according to claim 5, wherein said optical plate includes a filter element having its light transmissivity radially varied; and wherein said displacement detecting means includes half mirror means disposed midway of an optical path between said light source and said parallel reflector for guiding sideways the reflected highly directive light beam, and a photoelectric converter disposed sideways of said half mirror means at a position to receive the reflected light beam, which is transmitted through said filter element, for detecting the last-mentioned displacement in terms of the deviation in the quantities of light from a predetermined level of reference.
Claim 10
Dependent Claim
115 words
An apparatus according to claim 1, wherein said displacement detecting means includes half mirror means disposed midway of an optical path between said light source and said parallel reflector for guiding sideways the reflected highly directive light beam, a photoelectric converter disposed sideways of said half mirror means at a position to receive the reflected light beam and having a plurality of photoelectric elements for generating electric signals independently of each other when the reflected light beam is incident thereupon, and comparator means electrically connected to each of said photoelectric elements for comparing said electric signals so as to detect the last-mentioned displacement in terms of the difference among the respective levels of said voltages.
Claim 11
Dependent Claim
15 words
An apparatus according to claim 9, wherein said photoelectric elements have a shape of quadrant.
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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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |