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US 5,825,374 AGranted
Apparatus and method for advancing a web
AssigneeRaster Graphics, Inc.
InventorsDavid Albertalli, Gus Andriancen, Sasan Saadat
Life of this patent
Estimating the term…
Abstract
In an apparatus for intermittently advancing a web, only one surface of the web contacts moving parts of the apparatus. The apparatus includes, in a direction of movement of the web, a device for supplying the web, a first dancer roller arrangement, an intermittently driven drive roller, a second dancer roller arrangement, and a take-up device. The first and second dancer roller arrangements function to isolate a portion of the web from inertia in other portions of the web, and to provide substantially constant tension on opposite sides of the drive roller to prevent slippage and ensure accurate intermittent advancement of the web by the drive roller. A method for intermittently advancing a web is also disclosed.
Claims22
An apparatus in which a web is intermittently advanced, comprising:
- a driven supplying device for supplying a web of material;
- a driven take-up device for taking up the web of material;
- an intermittently driven drive roller, and a motor for intermittently rotating and stopping the drive roller as the supplying device supplies the web and as the take-up device takes up the web, the drive roller being disposed between the supplying device and the take-up device, a first surface of the web contacting the drive roller such that intermittent movement of the drive roller intermittently advances the web toward the take-up device;
- a first dancer roller arrangement between the drive roller and the supplying device, the first dancer roller arrangement including a first pivot point, a first roller pivotable about the first pivot point between a first and a second position, and a first urging device for urging the first roller toward the first position, the first surface of the web contacting the first roller;
- and
- a second dancer roller arrangement between the drive roller and the take-up device, the second dancer roller arrangement including a second pivot point, a second roller pivotable about the second pivot point between a first and a second position, and a second urging device for urging the second roller toward the first position, the first surface of the web contacting the second roller,
- wherein, when the drive roller advances the web, a length of the web between the supplying device and the drive roller decreases and causes the first roller to move toward the second position of the first roller against a force from the first urging device and a length of the web between the drive roller and the take-up device increases such that the second urging device moves the second roller to the first position of the second roller, when the supplying device supplies the web, a length of the web between the supplying device and the drive roller increases such that the first urging device moves the first roller to the first position of the first roller, and, when the take-up devices takes-up the web, a length of the web between the drive roller and the take-up device decreases and causes the second roller to move toward the second position of the second roller against a force from the second urging device.
4 more elements
An apparatus in which a web is intermittently advanced, comprising:
- a driven supplying device for supplying a web of material;
- a driven take-up device for taking up the web of material;
- an intermittently driven drive roller, and a motor for intermittently stopping and rotating the drive roller as the supplying device supplies the web and the take-up device takes up the web, the drive roller being disposed between the supplying device and the take-up device, a first surface of the web contacting the drive roller such that intermittent movement of the drive roller intermittently advances the web toward the take-up device;
- a first tensioning device, the first tensioning device being disposed between the drive roller and the supplying device and contacting the first surface of the web such that substantially constant tension is maintained in the web during intermittent movement of the drive roller and during no intermittent movement of the drive roller;
- a second tensioning device, the second tensioning device being disposed between the drive roller and the take-up device and contacting the first surface of the web such that substantially constant tension is maintained in the web during intermittent movement of the drive roller and during no intermittent movement of the drive roller.
2 more elements
A method in which a web is intermittently advanced, comprising the steps of:
- supplying a web of material from a supply point;
- taking up the web of material at a take-up point;
- intermittently moving a portion of the web between the supply point and the take-up point away from the supply point and toward the take-up point and stopping movement of the web with a drive device as the web is supplied and taken up;
- maintaining substantially constant tension in a portion of the web between the drive device and the supply point during intermittent movement of the web and during no intermittent movement of the web with a first tensioning device;
- maintaining substantially constant tension in a portion of the web between the drive device and the take-up point during intermittent movement of the web and during no intermittent movement of the web with a second tensioning device,
- wherein the drive device, the first tensioning device, and the second tensioning device contact only one surface of the web.
3 more elements
Dependencies are inferred from the claim text.