US3552251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary slit cutter
Assignee: Bobst Champlain Inc
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Filing: 1968-12-03
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Granted: 1971-01-05
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Expires: 1988-12-03
Abstract
Abstract The slit cutter comprises a rotary cylinder carrying knives, and a stationary fixed knife the cutting edge of which is ground away or relieved except at those parts along its length where the web is to be slit. All of the rotary knives cooperate with the resulting intermittent edge of the single fixed knife. The knives are preferably helically mounted on the cylinder, and the cylinder and fixed knife are skewed at an angle such that the resulting slits are perpendicular to the long axis of the web. There is a metering roll ahead of the knives, and a pull roll following the knives, both driven accurately at web speed, and serving to maintain control of the web independently of the knives, which are preferably but not necessarily driven at web speed. Means is provided to properly register the slits with the printing on the web.
Inventors
- 👤 Herbert E Neff
- 👤 William R Chestnut
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:45
CPC Classifications
B; B26; B26F; B26F1/00; B26F1/18; B26F1/20; B26D; B26D5/00; B26D5/20; B26D5/30; B26D5/32; B26D7/00; B26D7/26; B26D2007/2692; Y; Y10; Y10T; Y10T83/00; Y10T83/465; Y10T83/4693; Y10T83/4766; Y10T83/4795; Y10T83/4809; Y10T83/4818; Y10T83/4824; Y10T83/4827; Y10T83/4847
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
105 words
A rotary slit cutter for operating on a continuously moving web to produce a line of short slits extending transversely of the web, said cutter comprising a rotary knife cylinder having a plurality of knives substantially helically mounted thereon, each of said knives having a continuous cutting edge, a stationary or fixed knife having an intermittent cutting edge disposed in the path of the cutting edges of said rotary knives, said cylinder and fixed knife being mounted relative to the transverse axis of said web at an angle skewed an amount such that the resulting slits are perpendicular to the long axis of the web.
Claim 2
Dependent Claim
105 words
A rotary slit cutter for operating on a continuously moving web to produce a line of short slits extending transversely of the web, said cutter comprising a rotary knife cylinder having a plurality of knives substantially helically mounted thereon, each of said knives having a continuous cutting edge, a stationary or fixed knife having an intermittent cutting edge disposed in the path of the cutting edges of said rotary knives, said cylinder and fixed knife being mounted relative to the transverse axis of said web at an angle skewed an amount such that the resulting slits are perpendicular to the long axis of the web.
Claim 3
Dependent Claim
128 words
A rotary slit cutter for operating on a continuously moving, previously printed web to produce a line of short slits extending transversely of the web, said cutter comprising a rotary knife cylinder carrying a rotary knife having a cutting edge, a stationary or fixed knife having its edge disposed at the path of the said rotary cutting edge, the edge of one of said knives being cut away or relieved except at those parts along its length where the web is to be slit, means for sensing said print on said web and means operatively connected to said sensing means for momentarily varying the speed of said web relative to said rotary knife edges so as to afford registration of said slitS with the printing on said web.
Claim 4
Dependent Claim
128 words
A rotary slit cutter for operating on a continuously moving, previously printed web to produce a line of short slits extending transversely of the web, said cutter comprising a rotary knife cylinder carrying a rotary knife having a cutting edge, a stationary or fixed knife having its edge disposed at the path of the said rotary cutting edge, the edge of one of said knives being cut away or relieved except at those parts along its length where the web is to be slit, means for sensing said print on said web and means operatively connected to said sensing means for momentarily varying the speed of said web relative to said rotary knife edges so as to afford registration of said slitS with the printing on said web.
Claim 5
Dependent Claim
128 words
A rotary slit cutter for operating on a continuously moving, previously printed web to produce a line of short slits extending transversely of the web, said cutter comprising a rotary knife cylinder carrying a rotary knife having a cutting edge, a stationary or fixed knife having its edge disposed at the path of the said rotary cutting edge, the edge of one of said knives being cut away or relieved except at those parts along its length where the web is to be slit, means for sensing said print on said web and means operatively connected to said sensing means for momentarily varying the speed of said web relative to said rotary knife edges so as to afford registration of said slitS with the printing on said web.
Claim 6
Dependent Claim
128 words
A rotary slit cutter for operating on a continuously moving, previously printed web to produce a line of short slits extending transversely of the web, said cutter comprising a rotary knife cylinder carrying a rotary knife having a cutting edge, a stationary or fixed knife having its edge disposed at the path of the said rotary cutting edge, the edge of one of said knives being cut away or relieved except at those parts along its length where the web is to be slit, means for sensing said print on said web and means operatively connected to said sensing means for momentarily varying the speed of said web relative to said rotary knife edges so as to afford registration of said slitS with the printing on said web.
Claim 7
Dependent Claim
47 words
A rotary slit cutter as defined in claim 2, wherein the means for momentarily varying the speed of said web relative to said rotary knife edges comprises running register means operatively connected to said drive means for momentarily varying the rotational speed of said rotary knife cylinder.
Claim 8
Dependent Claim
49 words
A rotary slit cutter as defined in claim 2, in which said means for varying the speed of said web relative to said rotary knife edges comprises an adjustable compensator roll ahead of said knives adapted to momentarily vary the rate of feed of said web past said knives.
Claim 9
Dependent Claim
58 words
A rotary slit cutter as defined in claim 1 in which the skew angle of the knife cylinder and fixed knife is adjustable, and in which there are means for effectuating a gradual controlled adjustment of the skew angle, and additional means for locking the said knife cylinder and fixed knife against movement from the desired angular position.
Claim 10
Dependent Claim
58 words
A rotary slit cutter as defined in claim 1, in which the rotary knife cylinder has a shaft one end of which is driven by appropriate drive means, and in which there is a swivel joint between the driven end of the shaft and the said gearing in order to accommodate the skew angle of the knife cylinder.
Claim 11
Dependent Claim
77 words
A rotary slit cutter as defined in claim 6, in which there is a metering roll and a nip roll cooperating therewith for feeding the web to the knives at a desired web speed, and in which there is a pull roll and a nip roll cooperating therewith for pulling the web from the knives at the same desired web speed, said metering and pull rolls being geared to said rotary knife cylinder for operation in unison.
Claim 12
Dependent Claim
47 words
A rotary slit cutter as defined in claim 7 for operating on a previously printed web, in which a running register means is provided in the drive means of the rotary knife cylinder in order to afford registration of the slits with the printing on the web.
Claim 13
Dependent Claim
45 words
A rotary slit cutter as defined in claim 7 for operating on a previously printed web, in which there is a compensator roll ahead of the knives to provide registration adjustment for correction of the registration of the slits with the printing on the web.
Claim 14
Dependent Claim
57 words
A rotary slit cutter as defined in claim 1, in which the rotary knife is approximately helically mounted on the knife cylinder to produce a shear cut, and in which the cylinder and fixed knife are mounted at an angle skewed an amount such that the resulting slits are perpendicular to the long axis of the web.
Claim 15
Dependent Claim
60 words
A rotary slit cutter as defined in claim 10, in which the skew angle of the knife cylinder axis and the fixed knife is adjustable, and in which there are means for effectuating a gradual controlled adjustment of the skew angle, and additional means for locking the said knife cylinder and fixed knife against movement from the desired angular position.
Claim 16
Dependent Claim
58 words
A rotary slit cutter as defined in claim 10, in which the rotary knife cylinder has a shaft one end of which is driven by appropriate drive means and in which there is a swivel joint between the driven end of the shaft and the said gearing in order to accommodate the skew angle of the knife cylinder.
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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) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |