Patent US3772810A successfully refreshed from Google Patents.
US3894697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Paper shredder
Assignee: Pitney Bowes Inc
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Filing: 1974-04-19
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Granted: 1975-07-15
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Expires: 1994-04-19
Abstract
Abstract A sheet material shredding mechanism comprising a pair of strip forming rollers and a pair of shredding rollers. Sheet material, such as paper documents, is initially fed into the jaws of the shredding mechanism. The sheets of material are then drawn between the strip forming rollers, which comprise intermeshing serrated discs. The serrated discs grab the material and form the material into strips. The shredding rollers, which are located directly adjacent to the strip forming rollers, receive the stripped material, and break the strips into smaller pieces. The shredding rollers comprise a smooth roller which is in shredding engagement with a mating roller having a raised strip which spirals along the length of the roller to form a helix. Strips fed to the shredding rollers are progressively torn across the width of the document as the raised spiral strip portion rotates into engagement with its mating roller.
Inventors
- 👤 James Gordon Lawson
- 👤 Walter Joseph Hanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:33
CPC Classifications
B; B26; B26D; B26D11/00; B02; B02C; B02C18/00; B02C18/0007; B02C2018/0069
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
172 words
A shredding mechanism for shredding sheet material, comprising: strip forming means for receiving sheet material and causing said sheet material to form into strips of material; a pair of oppositely rotating shredding rollers located adjacent the strip forming means for receiving therebetween said strips of material from said strip forming means and causing said strips of material to be shredded into smaller pieces of material, one of said shredding rollers of said pair having at least one raised portion disposed upon a circumferential surface thereof, which said raised portion periodically rotates into shredDing engagement with the other roller of said pair of shredding rollers so as to shred said strips of material as said rollers oppositely rotate with respect to each other said strip forming means comprising a pair of oppositely rotating strip forming disc sets, and said shredding rollers rotating at a higher surface speed than the strip forming disc sets; and driving means operatively connected to said shredding rollers for rotating said shredding rollers into shredding engagement with each other.
Claim 2
Dependent Claim
172 words
A shredding mechanism for shredding sheet material, comprising: strip forming means for receiving sheet material and causing said sheet material to form into strips of material; a pair of oppositely rotating shredding rollers located adjacent the strip forming means for receiving therebetween said strips of material from said strip forming means and causing said strips of material to be shredded into smaller pieces of material, one of said shredding rollers of said pair having at least one raised portion disposed upon a circumferential surface thereof, which said raised portion periodically rotates into shredDing engagement with the other roller of said pair of shredding rollers so as to shred said strips of material as said rollers oppositely rotate with respect to each other said strip forming means comprising a pair of oppositely rotating strip forming disc sets, and said shredding rollers rotating at a higher surface speed than the strip forming disc sets; and driving means operatively connected to said shredding rollers for rotating said shredding rollers into shredding engagement with each other.
Claim 3
Dependent Claim
23 words
The shredding mechanism of claim 1, wherein said raised portion is an elongate strip disposed upon the circumferential surface of said shredding roller.
Claim 4
Dependent Claim
21 words
The shredding mechanism of claim 2, wherein said elongate strip forms a helix upon the circumferential surface of said shredding roller.
Claim 5
Dependent Claim
21 words
The shredding mechanism of claim 3, wherein said elongate strip is disposed substantially along an entire length of said shredding roller.
Claim 6
Dependent Claim
31 words
The shredding mechanism of claim 1, wherein each said strip forming disc set, comprises stripping discs, the stripping discs of each set intermeshing with the stripping discs of the other set.
References Cited (Backward Citations)
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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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |