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US4390774A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for treating electrically non-conductive workpieces

Assignee: National Research Development Corp UK
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Filing: 1981-03-24
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Granted: 1983-06-28
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Expires: 2001-03-24
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Abstract

Abstract Non-conductive workpieces present a problem where laser treatment of a workpiece is to be augmented by the application of an arc, since the arc cannot be struck to the workpiece. In the present invention a laser beam is augmented by an arc struck between two electrodes typically on opposite sides of the workpiece. The arc usually either penetrates the workpiece, or two arcs are formed on respective sides of the workpiece.

Inventors

  • 👤 William M. Steen
  • 👤 Walter W. Duley

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 16:00
CPC Classifications
B; B23; B23K; B23K26/00; B23K26/14; B23K26/1462; B23K26/1464; B23K26/147; B23K26/08; B23K26/083; B23K26/346; B23K26/348

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 65 words
A method for treating a workpiece comprising projecting a beam of light from a laser onto a workpiece formed from non-conductive material and applying a voltage between at least two electrodes, each distinct from said workpiece to strike an arc, the electrodes being so positioned that the arc impinges on the workpiece within a heat affected zone created by the laser beam in the workpiece.
Claim 2
Independent Claim 65 words
A method for treating a workpiece comprising projecting a beam of light from a laser onto a workpiece formed from non-conductive material and applying a voltage between at least two electrodes, each distinct from said workpiece to strike an arc, the electrodes being so positioned that the arc impinges on the workpiece within a heat affected zone created by the laser beam in the workpiece.
Claim 3
Dependent Claim 18 words
A method according to claim 1 wherein the workpiece is interposed between at least two of the electrodes.
Claim 4
Dependent Claim 13 words
A method according to claim 2 wherein the arc extends through the workpiece.
Claim 5
Dependent Claim 33 words
A method according to claim 1 wherein the arc extends from a first of the electrodes to the workpiece and a further arc extends from the workpiece to a second of the electrodes.
Claim 6
Dependent Claim 16 words
A method according to claim 1 wherein gas is projected towards the said heat affected zone.
Claim 7
Dependent Claim 13 words
A method according to claim 5 wherein the gas reacts with the workpiece.
Claim 8
Dependent Claim 30 words
A method according to claim 1 including so causing relative movement between the said zone and the workpiece while maintaining the arc that the treatment is carried out as required.
Claim 9
Dependent Claim 56 words
A method according to claim 1 for surface alloying, the workpiece including applying material, to be alloyed with a portion of the surface of the workpiece, to the said portion and so causing relative movement between the said zone and the workpiece that the said zone visits every point in the area to be surface alloyed.
Claim 10
Dependent Claim 23 words
A method according to claim 1 employing a plurality of arcs wherein a multi-phase electrical supply is used to strike the said arcs.
Claim 11
Dependent Claim 32 words
A method according to claim 7 wherein at least one of the electrtodes is positioned nearest the workpiece at a point in the workpiece where treatment is just about to take place.
Claim 12
Dependent Claim 69 words
Apparatus for treating a workpiece comprising means for projecting a laser beam on to a workpiece, at least first and second electrodes, each distinct from the workpiece and spaced apart from one another, and means for applying a voltage between the electrodes to strike an arc which, in operation, impinges on the workpiece at a point within a heat affected zone created by the laser beam in the workpiece.
Claim 13
Dependent Claim 69 words
Apparatus for treating a workpiece comprising means for projecting a laser beam on to a workpiece, at least first and second electrodes, each distinct from the workpiece and spaced apart from one another, and means for applying a voltage between the electrodes to strike an arc which, in operation, impinges on the workpiece at a point within a heat affected zone created by the laser beam in the workpiece.
Claim 14
Dependent Claim 28 words
Apparatus according to claim 11 wherein, in operation, the arc extends through the workpiece from one electrode to the other electrode, the arc passing through the workpiece material.
Claim 15
Dependent Claim 31 words
Apparatus according to claim 11 including means for causing relative movement between the said zone and the workpiece while maintaining the arc between one of the electrodes and the said zone.
Claim 16
Dependent Claim 41 words
Apparatus according to claim 13 wherein at least one of the electrodes is so positioned that, in operation, the distance between the workpiece and the said electrode is a minimum at a point where treatment is just about to take place.
Claim 17
Dependent Claim 15 words
Apparatus according to claim 11 including means for projecting gas towards the heat affected zone.
Claim 18
Dependent Claim 33 words
Apparatus according to claim 15 wherein the means for projecting gas does so from a position opposite one workpiece surface which receives the laser beam or from a position opposite another workpiece surface.
Claim 19
Dependent Claim 35 words
Apparatus according to claim 15 wherein the means for projecting gas does so from a first position opposite one workpiece surface which receives the laser beam and from a second position opposite another workpiece surface.
Claim 20
Dependent Claim 17 words
Apparatus according to claim 15 wherein the gas is exothermically reactive with at least one workpiece material.
Claim 21
Dependent Claim 37 words
Apparatus according to claim 11 including means for deflecting away from the laser beam at least part of the plume of materials which is emitted from the point of incidence of the laser beam on the workpiece.
Claim 22
Dependent Claim 43 words
Apparatus according to claim 11 constructed for operation from a multi-phase electrical supply, wherein the first electrode is arranged for connection to one phase, and at least one other electrode (which may be the second electrode) is arranged for connection to another phase.
Claim 23
Dependent Claim 19 words
Apparatus according to claim 20 wherein one electrode is arranged for connection to the neutral of a multi-phase supply.
Claim 24
Dependent Claim 20 words
A method according to claim 5 including applying a flux which reacts with the gas at the heat affected zone.

References Cited (Backward Citations)

US3569660A Cited
GB1547172A Cited
GB1600796A Cited
US4167662A Cited
US4322601A Cited
GB2045669A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-06-27 1986-12-27 1987-06-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-06-27 1990-12-27 1991-06-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-06-27 1994-12-27 1995-06-28 $7700.00 Window Closed / Lapsed

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