US3862396A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for making perforations in sheet material by electric discharge
Assignee: Sanyo Kokusaku Pulp Co Ltd
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Filing: 1974-02-04
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Granted: 1975-01-21
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Expires: 1994-02-04
Abstract
Abstract Apparatus for making perforations in sheet material by generating electric discharge through the sheet while passing the sheet between a group of discharge electrodes and a common grounded electrode and producing a gaseous stream in any desired amounts between and around the discharge electrodes and the surface of the sheet, thereby obtaining a perforated sheet having uniform perforation spacing and density as well as descreased scorching or blackening created around the perforations in the perforated sheet.
Inventors
- 👤 Chuichi Machida
- 👤 Kozo Tsuchida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:36
CPC Classifications
B; B26; B26F; B26F1/00; B26F1/26; B26F1/28
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
120 words
An apparatus for the perforation of a sheet comprising a plurality of discharge electrodes electrically insulated from each other, a common grounded electrode opposite thereto, said discharge electrodes and common grounded electrode being arranged to allow the sheet to pass therebetween and effect discharge therebetween through the sheet to produce perforations in the sheet, annular nozzle means disposed around and surrounding each of said discharge electrodes, each of said annular nozzle means having their axes perpendicularly to the sheet surface, means for establishing a gas stream, said nozzle means forming said gas stream in a direction perpendicular to the sheet surface, said gas stream passing between and Around each of said discharge electrodes and the sheet to control perforation conditions.
Claim 2
Independent Claim
120 words
An apparatus for the perforation of a sheet comprising a plurality of discharge electrodes electrically insulated from each other, a common grounded electrode opposite thereto, said discharge electrodes and common grounded electrode being arranged to allow the sheet to pass therebetween and effect discharge therebetween through the sheet to produce perforations in the sheet, annular nozzle means disposed around and surrounding each of said discharge electrodes, each of said annular nozzle means having their axes perpendicularly to the sheet surface, means for establishing a gas stream, said nozzle means forming said gas stream in a direction perpendicular to the sheet surface, said gas stream passing between and Around each of said discharge electrodes and the sheet to control perforation conditions.
Claim 3
Dependent Claim
47 words
An apparatus as claimed in claim 1, wherein said means for establishing a gas stream includes a compressed gas supply, said nozzle means being connected to said compressed gas supply, thereby ejecting a compressed gas stream in a direction from the nozzles perpendicularly to the sheet surface.
Claim 4
Dependent Claim
55 words
An apparatus as claimed in claim 1, wherein each of said nozzle means includes a nozzle having an annular projection at the peripheral portion thereof opposing the sheet surface, a suction means, said annular projection being connected to said suction means, thereby generating a drawn gas stream between the sheet surface and the discharge electrodes.
Claim 5
Dependent Claim
54 words
An apparatus as claimed in claim 2, including a stepup transformer and a high frequency pulse source, said discharge electrodes being connected via said step-up transformer to said high frequency pulse source to form an independent discharge circuit thereby applying a high frequency pulse of high voltage and small current to said discharge electrode.
Claim 6
Dependent Claim
67 words
An apparatus as claimed in claim 4, wherein said step-up transformer comprises a pair of ignition coils, a primary winding connected to the high frequency pulse source, and a center-tapped secondary winding, the opposite ends of said secondary winding being connected to a pair of said discharge electrodes whereas said center-tapped secondary winding is grounded, thus applying to said pair of discharge electrodes voltages of opposite polarity.
Claim 7
Dependent Claim
54 words
An apparatus as claimed in claim 3, including a step-up transformer and a high frequency pulse source, said discharge electrodes being connected via said step-up transformer to said high frequency pulse source to form an independent discharge circuit thereby applying a high frequency pulse or high voltage and small current to said discharge electrode.
Claim 8
Dependent Claim
67 words
An apparatus as claimed in claim 6, wherein said step-up transformer comprises a pair of ignition coils, a primary winding connected to the high frequency pulse source, and a center-tapped secondary winding, the opposite ends of said secondary winding being connected to a pair of said discharge electrodes whereas said center-tapped secondary winding is grounded, thus applying to said pair of discharge electrodes voltages of opposite polarity.
Claim 9
Dependent Claim
55 words
An apparatus as claimed in claim 1 wherein each of said nozzle means is constructed and arranged to direct said gas stream in a manner to control the perforation spacing, perforation density, the diameter of the perforations formed, and any blackening and scorching which may be produced at the peripheral edge portions of the perforations.
Claim 10
Dependent Claim
20 words
An apparatus as claimed in claim 1 wherein said gas stream includes an inert gas to prevent scorching and blackening.
Claim 11
Dependent Claim
18 words
An apparatus as claimed in claim 1 wherein said discharge electrodes have discharge ends spaced from said sheet.
Claim 12
Dependent Claim
18 words
An apparatus as claimed in claim 3 wherein said annular projections on said nozzles slidably contact said sheet.
Claim 13
Dependent Claim
24 words
An apparatus as claimed in claim 1 wherein each of said nozzle means includes a nozzle arranged in circumscribing relationship about individual discharge electrodes.
Claim 14
Dependent Claim
42 words
An apparatus as claimed in claim 1 wherein each of said nozzle means includes a nozzle comprising a gas discharge passage having an axis perpendicular to said sheet, each of said discharge nozzles being centrally disposed within one of said discharge passages.
Claim 15
Dependent Claim
24 words
An apparatus as claimed in claim 1 wherein each of said nozzle means includes a nozzle having a toroidal opening circumscribing said discharge electrode.
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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) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |