(19) |
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(11) |
EP 0 245 112 A3 |
(12) |
EUROPEAN PATENT APPLICATION |
(88) |
Date of publication A3: |
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07.02.1990 Bulletin 1990/06 |
(43) |
Date of publication A2: |
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11.11.1987 Bulletin 1987/46 |
(22) |
Date of filing: 08.05.1987 |
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(51) |
International Patent Classification (IPC)4: B26F 1/28 |
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(84) |
Designated Contracting States: |
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BE DE FR GB IT NL |
(30) |
Priority: |
08.05.1986 GB 8611256
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(71) |
Applicant: BCL LIMITED |
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Bridgwater
Somerset TA6 4PA (GB) |
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(72) |
Inventors: |
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- Clegg, Alan James
Worle
Weston-Super-Mare
Avon BS22 9NL (GB)
- Smith, John Colin Dinsdale
Spaxton
Bridgwater
Somerset TA5 1AA (GB)
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(74) |
Representative: Hardisty, David Robert et al |
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BOULT, WADE & TENNANT
27 Furnival Street London EC4A IPQ London EC4A IPQ (GB) |
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(54) |
Film perforating apparatus |
(57) The invention is concerned with an apparatus and a process for perforating synthetic
plastics film, for example polyethylene or polypropylene, with an electrical spark
discharge set up between a set of first electrodes which may be pointed rods and second
electrodes which also may be complementary pointed rods or a single electrode which
may be an electrically conducting guide plate, vane or roller. The film is drawn between
the first and second electrodes. Each first electrode is supplied with high voltage
sufficient to cause the spark discharge from a separate charged capacitor whereby
each first electrode is electrically isolated from the others and thus a discharge
from one first electrode does not prevent the formation of discharges from the other
electrodes. The charging and discharge of the capacitors is controlled by a series
of coupled switching units.