US3813981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Paper trimming knife system
Assignee: Advance Enterprises Inc
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Filing: 1973-06-18
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Granted: 1974-06-04
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Expires: 1993-06-18
Abstract
Abstract A rotary cutting knife for trimming signatures of multiple thicknesses of paper, such as folded press products, said knife having sharply pointed teeth around the periphery thereof, one surface of each tooth being planar, within the plane of one surface of said knife, and the edges of said teeth being beveled from the opposite surface at an acute angle to said one surface of said knife to provide camming surfaces on said teeth operable to engage a plurality of superimposed sheets of paper, including especially sheets folded upon themselves, and prevent the same from moving away from said planar surfaces of said teeth while shearing such paper by coaction of said teeth with a rotary bed knife having a planar face slidable in shearing relationship with said planar surfaces of said teeth on said cutting knife. During a rotary shearing operation, leading teeth of said cutting knife engage and progressively pierce the adjacent surfaces of said sheets of paper to maintain an intended line of cut accurately in alignment with the planar surface of said cutting knife and such penetrating movement into said paper continuing at least to the full depth of said teeth for shearing coaction with said rotary bed knife and thereby form a smoothly sheared accurate edge along one side of said paper.
Inventors
- 👤 H Faltin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:15
CPC Classifications
B; B26; B26D; B26D1/00; B26D1/01; B26D1/12; B26D1/14; B26D1/24; B26D1/245; B26D1/0006; B26D2001/0046; B26D2001/006; B26D2001/0066; Y; Y10; Y10T; Y10T83/00; Y10T83/768; Y10T83/7809; Y10T83/783; Y10T83/929; Y10T83/9372; Y10T83/9403; Y10T83/9457; Y10T83/9464; Y10T83/9469; Y10T83/9471
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
291 words
A paper trimming system comprising in combination, a rotary bed knife having a substantially cylindrical surface terminating at least at one end in a planar face to provide a smooth circular shearing edge, and a circular rotary cutting knife having at least one planar surface the outer portion of which slidably overlies said planar face of said rotary bed knife in shearing relationship therewith, said knives having central openings to adapt the same to be mounted upon shafts and be driven in directions to effect shearing of separate assemblies of superimposed sheets of paper; the periphery of said cutting knife having gripping and shearing teeth formed thereon, the sides of said teeth subtending equal angles between 45* and 75* to provide sharp apex ends, one face of each tooth being planar within the plane of said planar face of said cutting knife and the opposite edges of said teeth being similarly beveled at an acute angle to the plane of said planar face to provide sharp cutting edges on each side of said teeth which meet at a sharp point within said planar face; said teeth in cutting operation slidably overlying said planar face of said rotary bed knife for at least the full length of said teeth to form a smoothly trimmed edge upon separate assemblies of sheets fed to said knives and also providing a total extent of shearing edge upon said cutting knife which is greatly in excess of the circumference of said cutting knife, and said sharp points and beveled edges of said teeth providing camming means operable to penetrate the sheets being trimmed in a manner to maintain the intended line of cut for said sheets accurately aligned with the coacting shearing edges of said knives.
Claim 2
Dependent Claim
291 words
A paper trimming system comprising in combination, a rotary bed knife having a substantially cylindrical surface terminating at least at one end in a planar face to provide a smooth circular shearing edge, and a circular rotary cutting knife having at least one planar surface the outer portion of which slidably overlies said planar face of said rotary bed knife in shearing relationship therewith, said knives having central openings to adapt the same to be mounted upon shafts and be driven in directions to effect shearing of separate assemblies of superimposed sheets of paper; the periphery of said cutting knife having gripping and shearing teeth formed thereon, the sides of said teeth subtending equal angles between 45* and 75* to provide sharp apex ends, one face of each tooth being planar within the plane of said planar face of said cutting knife and the opposite edges of said teeth being similarly beveled at an acute angle to the plane of said planar face to provide sharp cutting edges on each side of said teeth which meet at a sharp point within said planar face; said teeth in cutting operation slidably overlying said planar face of said rotary bed knife for at least the full length of said teeth to form a smoothly trimmed edge upon separate assemblies of sheets fed to said knives and also providing a total extent of shearing edge upon said cutting knife which is greatly in excess of the circumference of said cutting knife, and said sharp points and beveled edges of said teeth providing camming means operable to penetrate the sheets being trimmed in a manner to maintain the intended line of cut for said sheets accurately aligned with the coacting shearing edges of said knives.
Claim 3
Dependent Claim
21 words
The paper trimming machine according to claim 1 in which the sides of said teeth subtend an angle of substantially 60*.
Claim 4
Dependent Claim
30 words
The paper trimming machine according to claim 1 in which the sides of said teeth respectively are disposed substantially evenly on opposite sides of the radial axes of the teeth.
Claim 5
Dependent Claim
48 words
The paper trimming machine according to claim 1 in which the opposite faces of said rotary bed knife are planar and said bed knife being reversible end-for-end upon a shaft respectively to present the opposite faces of said bed knife for shearing cooperation with said rotary cutting knife.
Claim 6
Dependent Claim
123 words
The paper trimming machine according to claim 1 further including a pair of parallel shafts, means on one of said shafts providing seats spaced longitudinally thereon a distance equal to the trimmed width of sheets of paper to be trimmed by said machine, a pair of said rotary cutting knives respectively being mounted upon said seats with the planar surfaces of said knives facing each other, means to clamp said knives to said seats, and means to clamp a pair of said rotary bed knives on the other shaft with the outer faces thereof spaced a distance substantially equal to the trimmed width of sheets to be trimmed by said machine for shearing cooperation with said rotary cutting knives on said first-mentioned shaft.
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) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |