US4717085A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Document shredding machines
Assignee: Ofrex Group Holdings PLC
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Filing: 1985-12-18
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Granted: 1988-01-05
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Expires: 2005-12-18
Abstract
Abstract A document shredding machine comprises cutting mechanism comprising two shafts, each mounted for rotation about a respective parallel axis, and cutting discs mounted at spaced intervals on each shaft, the two sets of cuttings discs intermeshing and the shafts being rotated in opposite directions so as to provide a downwardly-accessible nip into which documentary material (such as paper) is fed. Engagement between the circumferential edges of adjacent discs subjects the documentary material to a plurality of longitudinal cuts, and the discs are provided with transverse cutting edges by which the material is subjected to a transverse severing.
Inventors
- 👤 Denis P. Crane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:06
CPC Classifications
B; B02; B02C; B02C18/00; B02C18/0007
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
154 words
In a document shredding machine, a cutting mechanism comprising two shafts mounted for rotation about parallel axes, cutting discs at spaced intervals on each shaft with the discs on one shaft intermeshing with the discs of the other shaft, means for rotating the shafts in opposite directions so as to provide a downwardly-accessible nip into which documentary material may be fed, the discs being provided with transverse cutting edges to subject the material to a transverse severance, the cutting discs on each shaft being arranged in a plurality of sets with the cutting edges of the discs of each set being located on helices corresponding in number to the cutting edges of each disc and extending longitudinally of the shaft and circumferentially intermediate the adjacent helices on which the cutting edges of the discs of adjacent sets are located, and the discs of each set alternating longitudinally with the discs of each adjacent set.
Claim 2
Dependent Claim
154 words
In a document shredding machine, a cutting mechanism comprising two shafts mounted for rotation about parallel axes, cutting discs at spaced intervals on each shaft with the discs on one shaft intermeshing with the discs of the other shaft, means for rotating the shafts in opposite directions so as to provide a downwardly-accessible nip into which documentary material may be fed, the discs being provided with transverse cutting edges to subject the material to a transverse severance, the cutting discs on each shaft being arranged in a plurality of sets with the cutting edges of the discs of each set being located on helices corresponding in number to the cutting edges of each disc and extending longitudinally of the shaft and circumferentially intermediate the adjacent helices on which the cutting edges of the discs of adjacent sets are located, and the discs of each set alternating longitudinally with the discs of each adjacent set.
Claim 3
Dependent Claim
63 words
A cutting mechanism of the character defined in claim 1, wherein each disc of each set has an odd number of equally spaced cutting edges, a central hole therethrough for fitting about a shaft, and diametrically opposed parts for engaging diametrically opposed parts on the shaft, whereby the cutting edges of adjacent discs are circumferentially staggered when the parts thereof are diametrically reversed.
Claim 4
Dependent Claim
177 words
In a document shredding machine, a cutting mechanism comprising two shafts mounted for rotation about parallel axes, cutting discs at spaced intervals on each shaft with the discs on one shaft intermeshing with the discs of the other shaft, means for rotating the shafts in opposite directions so as to provide a downwardly-accessible nip into which documentary material may be fed, the discs being provided with transverse cutting edges to subject the material to a transverse severance, the cutting discs on each shaft being arranged in a plurality of sets with the cutting edges of the discs of each set being located on helices corresponding in number to the cutting edges of each disc and extending longitudinally of the shaft and circumferentially intermediate the adjacent helices on which the cutting edges of the discs of adjacent sets are located, the circumferential extent of each helix being not greater than 360° divided by the number of cutting edges of each disc, and the helices of each set being substantially equally spaced circumferentially of the helices of adjacent sets.
Claim 5
Dependent Claim
177 words
In a document shredding machine, a cutting mechanism comprising two shafts mounted for rotation about parallel axes, cutting discs at spaced intervals on each shaft with the discs on one shaft intermeshing with the discs of the other shaft, means for rotating the shafts in opposite directions so as to provide a downwardly-accessible nip into which documentary material may be fed, the discs being provided with transverse cutting edges to subject the material to a transverse severance, the cutting discs on each shaft being arranged in a plurality of sets with the cutting edges of the discs of each set being located on helices corresponding in number to the cutting edges of each disc and extending longitudinally of the shaft and circumferentially intermediate the adjacent helices on which the cutting edges of the discs of adjacent sets are located, the circumferential extent of each helix being not greater than 360° divided by the number of cutting edges of each disc, and the helices of each set being substantially equally spaced circumferentially of the helices of adjacent sets.
Claim 6
Dependent Claim
25 words
A cutting mechanism of the character defined in claim 3, wherein the discs of each set alternate longitudinally with the discs of each adjacent set.
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) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |