Web feed tractor belt assembly
US4874121A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 3, 1988 |
| Grant date | Oct 17, 1989 |
| Priority date | — |
| Expiry date | May 3, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J11/30
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A web feed tractor mechanism 10 is illustrated in the drawings for moving a web material in a longitudinal direction in which the web material has perforations along edge sections 16 and 18 for enabling precision movement of the web particularly for use in computer output printing. The web tractor mechanism has two parallel tractors 34 and 36 that support and drive tractor drive belts 54 and 56. The belts 54 and 56 have drive pins 70 and 72 respectively for engaging the perforations along the opposite side edge section 16 and 18. Preferably the pins 70 have a reduced cross-section that is both longitudinally and laterally symmetrical, with lateral and longitudinal dimensions that are substantially equal. The surfaces of the pins 70 engage the inside edge of the perforations and drive the web forward while preventing lateral movement of the edge section 16 to provide lateral stability. The pins 72 have a reduced cross-section in the lateral direction to accommodate misalignments and inaccuracies in the lateral direction of the pins and/or perforations to accurately and rapidly move the web in the logitudinal direction. This feature improves the accuracy and quality of the printing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.