Device for compensating for the offset of a sheet element on rollers, in particular for a poster board having moving posters
US4168039A · kind A · utility
Inventor
Key dates
| Filing date | Nov 1, 1978 |
| Grant date | Sep 18, 1979 |
| Priority date | — |
| Expiry date | Nov 1, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09F2011/009
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The device compensates for the offset of a sheet element which is movably mounted on at least two parallel rollers which are alternately supply and receiving rollers. At least one (1) of these rollers is inclinable relative to the other and is controlled by means (17-20) for detecting the offset of the sheet element and acting on compensating means (3-12) which modify the angle of the inclinable roller. This device comprises an offset compensating member (3) which normally rotates with the inclinable roller when the sheet element is correctly centered. The rotation of the compensating member is temporarily interrupted and converted into a linear displacement by the action of at least one abutment (9) which is shifted by the detecting means when the latter detects an offset of the sheet element. The compensating means cooperates, in its linear displacement, with the profile of a cam (12) which modifies the position of one end of the inclinable roller and consequently the angle of the latter. The invention is applicable to the control of the offset of any element in the form of a sheet or band held taut on two rollers or reels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.