Title: Apparatus for thermally machining thermoplastics sheet

Abstract: An apparatus for thermally machining thermoplastics sheet, i.e. cutting and/or welding the sheet, uses a laser. The sheet is tensioned over a backing member of a suitable refractory material such as fused silica. The laser beam is focussed on the sheet over the backing member and the laser energy passing through the sheet is absorbed in the surface layers of the backing member which is highly absorbing at the laser output wavelength. The material of the backing material also has a low thermal diffusivity so that a hot spot is formed at the point where the focussed laser beam is incident. Because the sheet is held in intimate contact with the backing member, heat from the hot spot passed back into the sheet to aid machining.

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Other info:

Inventors: Lee, Michael John (Didcot, EN)

Application Number: 617656
Filing Date: 1975-09-29
Publication_date: 1976-09-21
Assignee: A. J. Bingley Limited (Bristol, EN)
Primary Class(es): 493/196 156/380.9, 219/121.63, 219/121.67, 219/121.8, 219/121.82, 493/203, 493/210
Other Classes:
US Patent Ref:

3004881	Oct, 1961	Van der Meulen	93/8.
3247041	Apr, 1966	Henderson	156/380.
3419706	Dec, 1968	Lohrmann	219/121.
3626143	Dec, 1971	Fry	219/121.
3838631	Oct, 1974	Simpson et al.	93/8.
3909582	Sep, 1975	Bowen	219/121.

Other Refs:
Primary Examiner: Coan, James F.
Assistant Examiner:
Attorney: Larson, Taylor and Hinds