US4380694A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser cutting apparatus
Assignee: LASER ECOSSE Ltd
•
Filing: 1981-02-18
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Granted: 1983-04-19
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Expires: 2001-02-18
Abstract
Abstract Laser cutting apparatus comprises a laser (20), means (24,25) for directing the output beam of the laser on to a workpiece (26), and means such as a quarter-wave plate (27) for producing circular polarization of the laser output beam. The laser may include within its optical cavity an element which produces stable linear polarization of the output beam. The quarter-wave plate (27) then covers the polarization into circular polarization.
Inventors
- 👤 David J. Dyson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:16
CPC Classifications
B; B23; B23K; B23K26/00; B23K26/02; B23K26/06; B23K26/0665; B23K26/064; B23K26/0643; B23K26/0648
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
61 words
Laser cutting apparatus for cutting a workpiece along a predetermined line comprising a laser producing a continuous output beam while in operation, means for producing circular polarization of the laser output beam, and means for directing the circularly polarized laser output beam onto the workpiece whereby a cut of uniform section is produced in the workpiece in any direction of cut.
Claim 2
Dependent Claim
61 words
Laser cutting apparatus for cutting a workpiece along a predetermined line comprising a laser producing a continuous output beam while in operation, means for producing circular polarization of the laser output beam, and means for directing the circularly polarized laser output beam onto the workpiece whereby a cut of uniform section is produced in the workpiece in any direction of cut.
Claim 3
Dependent Claim
26 words
Apparatus as claimed in claim 1 in which the laser includes within its optical cavity an element which produces stable linear polarisation of the output beam.
Claim 4
Dependent Claim
14 words
Apparatus as claimed in claim 2 in which the element comprises a Brewster-angle window.
Claim 5
Dependent Claim
26 words
Apparatus as claimed in claim 2 in which laser has a folded optical cavity having reflecting folding means, the element comprising one of said folding means.
Claim 6
Dependent Claim
24 words
Apparatus as claimed in claim 1 in which the control means comprise a quarter-wave plate a birefringent material located in the laser output beam.
Claim 7
Dependent Claim
19 words
Apparatus as claimed in claim 5 in which a coated quater-wave plate forms the output mirror of the laser.
Claim 8
Dependent Claim
25 words
Apparatus as claimed in claim 1 in which the means for producing circular polarization comprise a quarter-wave plate mirror located in the laser output beam.
References Cited (Backward Citations)
US3388314A
Cited
US3430158A
Cited
US3754195A
Cited
US4069458A
Cited
US4139263A
Cited
US4116542A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-18 | 1986-10-18 | 1987-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-18 | 1990-10-18 | 1991-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-18 | 1994-10-18 | 1995-04-19 | $7700.00 | Window Closed / Lapsed |