Patent US3644953A successfully refreshed from Google Patents.
US3644953A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet-cleaning apparatus
Assignee: 3M Co
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Filing: 1970-06-08
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Granted: 1972-02-29
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Expires: 1990-06-08
Abstract
Abstract An inexpensive manually operated device for thoroughly cleaning photographic film negatives. The device includes two pneumatically inflated cylinders that press two lengths of wiping cloth into even and intimate contact with opposite surfaces of a negative passed between the lengths of cloth. The device blows ionized air across the negative after it is wiped clean to neutralize any static electrical charges present on the negative.
Inventors
- 👤 Robert W Christiansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:45
CPC Classifications
H; H05; H05F; H05F3/00; H05F3/04; G; G03; G03D; G03D15/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
169 words
A cleaning apparatus for the removal of dust and other foreign objects from a sheet upon movement of a said sheet through said apparatus, said apparatus comprising: a pair of hollow tubular support members having flexible semicylindrical walls positioned in opposed relationship to each other to define opposed parallel narrow support edges; two lengths of soft, lint-free wiping cloth extending between said support members, the opposed surfaces of the sections of cloth between said narrow support edges defining part of a path through which a said sheet to be cleaned may be passed; pressure means coupled with said support members for providing fluid under a predetermined constant pressure within said support members; and support means for supporting the wall of each flexible support member in an area opposite said support edge to urge said sections of flexible cloth toward each other with essentially an equal pressure distribution along said support edges to afford intimate uniform pressure for cleaning between said sections of cloth and the surfaces of said sheet.
Claim 2
Dependent Claim
169 words
A cleaning apparatus for the removal of dust and other foreign objects from a sheet upon movement of a said sheet through said apparatus, said apparatus comprising: a pair of hollow tubular support members having flexible semicylindrical walls positioned in opposed relationship to each other to define opposed parallel narrow support edges; two lengths of soft, lint-free wiping cloth extending between said support members, the opposed surfaces of the sections of cloth between said narrow support edges defining part of a path through which a said sheet to be cleaned may be passed; pressure means coupled with said support members for providing fluid under a predetermined constant pressure within said support members; and support means for supporting the wall of each flexible support member in an area opposite said support edge to urge said sections of flexible cloth toward each other with essentially an equal pressure distribution along said support edges to afford intimate uniform pressure for cleaning between said sections of cloth and the surfaces of said sheet.
Claim 3
Dependent Claim
38 words
An apparatus according to claim 1 further comprising nuclear ionizing means for alpha particle emission mounted on said apparatus for ionizing air along said path to neutralize static electrical charges on a said sheet moved through said apparatus.
Claim 4
Dependent Claim
124 words
An apparatus according to claim 2 wherein said pressure means comprises: a centrifugal blower; and a duct attached between the outlet of said blower and said support members for directing air under pressure from said blower to said support members, said duct formed with an orifice positioned along said path for a said sheet to direct a stream of air across said path, and wherein said nuclear ionizing means is attached to the outlet of said blower for ionizing air pressurized by said blower so that said stream of air directed across said path will be ionized and will neutralize static electric charges on both surfaces of a said sheet moved through said apparatus after a said sheet has been cleaned by said apparatus.
Claim 5
Dependent Claim
15 words
An apparatus according to claim 3 wherein said nuclear alpha particle source comprises encapsulated polonium.
Claim 6
Dependent Claim
46 words
An apparatus according to claim 1 wherein said lint-free cloth is a random woven cloth comprising fine denier, nonlinting polypropylene fibers and means for bonding said fibers together to avoid the transfer of any material forming said cloth to a said sheet moved through said apparatus.
Claim 7
Dependent Claim
47 words
An Apparatus according to claim 1 wherein said lint-free cloth is a random woven cloth comprising fine denier, nonlinting polypropylene fibers and a transfer-free bonding means for bonding said fibers together to avoid the transfer of said bonding means to a said sheet moved through said apparatus.
Claim 8
Independent Claim
200 words
An apparatus for cleaning a sheet upon movement thereof along a path defined on said apparatus, which apparatus has cleaning means mounted along said path for removing dust and other foreign objects from both surfaces of a said sheet and ionizing means for ionizing air along said path to remove static electric charges from both surfaces of said sheet, wherein said ionizing means comprises a nuclear alpha particle source, and said cleaning means comprises a pair of adjacent flexible, resilient support members having opposed semicylindrical surfaces to define opposed narrow, parallel support edges defining a nip therebetween, which nip is disposed transverse to said path; two lengths of soft, lint-free wiping cloth extending through said nip, the opposed surfaces of the sections of cloth between said narrow support edges defining part of said path, said support members providing low even pressure to urge the opposed surfaces of said sections of cloth toward each other with essentially equal pressure distribution along said support edges when said edges and said lengths of cloth are moved away from each other at said nip by the passage of a said sheet therebetween; and means for advancing the lengths of cloth between said support edges.
Claim 9
Independent Claim
200 words
An apparatus for cleaning a sheet upon movement thereof along a path defined on said apparatus, which apparatus has cleaning means mounted along said path for removing dust and other foreign objects from both surfaces of a said sheet and ionizing means for ionizing air along said path to remove static electric charges from both surfaces of said sheet, wherein said ionizing means comprises a nuclear alpha particle source, and said cleaning means comprises a pair of adjacent flexible, resilient support members having opposed semicylindrical surfaces to define opposed narrow, parallel support edges defining a nip therebetween, which nip is disposed transverse to said path; two lengths of soft, lint-free wiping cloth extending through said nip, the opposed surfaces of the sections of cloth between said narrow support edges defining part of said path, said support members providing low even pressure to urge the opposed surfaces of said sections of cloth toward each other with essentially equal pressure distribution along said support edges when said edges and said lengths of cloth are moved away from each other at said nip by the passage of a said sheet therebetween; and means for advancing the lengths of cloth between said support edges.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |