US3799038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Curl corrector apparatus for operating on a continuous web
Assignee: Masson Scott Thrissell Engineering Ltd
•
Filing: 1972-03-27
•
Granted: 1974-03-26
•
Expires: 1992-03-27
Abstract
Abstract A curl corrector apparatus has corrector rods around which a continuous web is trained, as it is being unwound, to remove residual curl. These rods are adjustable and are moved to the most effective correcting position in response to signals derived from the web downstream of the corrector rods. When the web is subsequently cut into sheets, any curl in these sheets can be detected, preferably optically or sonically, and corrective signals obtained. When the web is continuous, mechanical sensing means can detect the direction in which the web tends to bow and hence provide a corrective signal.
Inventors
- 👤 W Bossons
- 👤 H Lindstaedt
- 👤 G Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:53
CPC Classifications
B; B65; B65H; B65H23/00; B65H23/04; B65H23/34
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
167 words
Apparatus for processing sheet material comprising a curl corrector device for operating on a continuous running web of paper, cardboard or like material and including an elongated member over which the web runs and means for displacing said member transversely to the path of the web to vary the curl correcting effect of said member, cutting means downstream of the curl corrector device for cutting the web into individual sheets, means for conveying the sheets away from the cutting means in a generally horizontal path, substantially continuous beam transmitting and receiving means focused on the conveying means, and means for feeding back the received beam signal, which varies as the curl of the sheets on the conveying means, to the curl corrector displacing means, the feedback means including means for discriminating between different signal waveforms characteristic of different directions of curl and means for applying to the displacing means a signal whose effect will be to move said member in the direction required to reduce the curl.
Claim 2
Dependent Claim
167 words
Apparatus for processing sheet material comprising a curl corrector device for operating on a continuous running web of paper, cardboard or like material and including an elongated member over which the web runs and means for displacing said member transversely to the path of the web to vary the curl correcting effect of said member, cutting means downstream of the curl corrector device for cutting the web into individual sheets, means for conveying the sheets away from the cutting means in a generally horizontal path, substantially continuous beam transmitting and receiving means focused on the conveying means, and means for feeding back the received beam signal, which varies as the curl of the sheets on the conveying means, to the curl corrector displacing means, the feedback means including means for discriminating between different signal waveforms characteristic of different directions of curl and means for applying to the displacing means a signal whose effect will be to move said member in the direction required to reduce the curl.
Claim 3
Dependent Claim
21 words
Apparatus according to claim 1, in which the beam transmitting means produces a light beam and the receiving means is photo-sensitive.
Claim 4
Dependent Claim
23 words
Apparatus according to claim 1, in which the beam transmitting means produces a sonic, pulsed beam and the receiving means is acoustically sensitive.
Claim 5
Dependent Claim
46 words
Apparatus according to claim 3, in which the discriminating means are adapted to sense the transit time of the sonic pulses to and from sheets on the conveying means and to produce signals indicative of the separation of the transmitting and receiving means from the sheets.
Claim 6
Dependent Claim
50 words
Apparatus according to claim 3, in which the discriminating means are adapted to sense the transit time of the sonic pulses to and from sheets on the conveying means and to produce signals indicative of the rate of change of separation of the transmitting and receiving means from the sheets.
Claim 7
Dependent Claim
24 words
Apparatus according to claim 1, and further comprising a diverter responsive to said discriminating means for diverting excessively curled sheets to a disposal region.
Claim 8
Dependent Claim
28 words
Apparatus according to claim 1, including means for driving the conveying means at a speed such thAt sheets delivered from the cutting means overlap on the conveying means.
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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |