Advancing material of indeterminate length – Means to engage longitudinally spaced modifications in material – Pins on flexible belt or chain
Patent
1985-10-10
1987-07-07
Levy, Stuart S.
Advancing material of indeterminate length
Means to engage longitudinally spaced modifications in material
Pins on flexible belt or chain
226 92, B41J 1126, B65H 2020
Patent
active
046781099
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a device in tractor mechanisms for paper traction feed printers and typewriters, this mechanism containing in a holder an endless belt, which is mounted for movement along its endless direction, as well as a drive connection for the belt, which belt has external teeth intended to drive a printing medium such as a paper web or the like through the printer on movement of the belt, by engagement with a row of holes along an edge of the medium, the holed edge and the toothed belt running in a gap defined by two wall portions of the holder, the height of the gap being less than the height of the teeth plus the thickness of the belt, with the wall portion facing towards the teeth having a groove for them.
BACKGROUND ART
Such a tractor mechanism is known, inter alia from the U.S. Pat. No. 3,825,162. For advancing a paper web in one direction through a printer there are two tractor mechanisms of this kind arranged with their respective holders movable on two parallel, horizontal rods, of which one is a drive shaft. More specifically, the toothed belt in each tractor mechanism runs over two rollers mounted in the holder, the drive shaft being in driving engagement with one of the wheels by the above-mentioned drive connection. The printer contains a motor which rotates the drive shaft.
Of the holders, the grooved wall portion is situated on a pivotable lid, the gap and the portion of the toothed belt running through it being uncovered by raising the lid. With the lids pivoted the paper web is brought in between the tractor mechanisms with both its holed edges in engagement with the toothed belt of the respective mechanism, subsequent to which the lids are repivoted. The paper is then securely held for advancing through the gaps in the tractor mechanisms.
A problem with printers provided with tractor mechanisms of the kind described above is that the mechanisms in certain cases may be located comparatively inaccessibly in the printer, so that inserting the paper by pivoting up the lids is made difficult. This problem is particularly apparent in types of printers where each tractor mechanism has two mutually opposing gaps on either side of the holder, these gaps being of the kind mentioned above with associated lids, the paper web running through both gaps and thus engaging twice with each toothed belt. The advantage of this type of paper feeding is that it facilitates movement of the paper web in the reverse direction. With relation to insertion of the paper, however, one of the gaps is usually situated considerably more inaccessibly than the other, e.g. under it.
DISCLOSURE OF INVENTION
The object of the invention has been to solve the above-mentioned problems and to provide, in tractor mechanisms of the kind described in the introduction, a device which considerably simplifies inserting the printing medium in the printer.
The foundation of the invention lies in the knowledge that insertion of the printing medium is considerably simplified if it can be fed into the tractor mechanism in the running direction of the toothed traction belts without needing to pivot the lids. More specifically, the above-mentioned object has been achieved by a device of the kind mentioned in the introduction having been given the characterizing features disclosed in claim 1.
Advantageous embodiments of the invention have been given the characterizing features disclosed in the respective subclaims.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be described in detail below with reference to the accompanying drawings on which
FIG. 1 illustrates in perspective a tractor mechanism for a traction feed printer, equipped with a device in accordance with the invention,
FIG. 2 is an exploded view of this device, while FIGS. 3 and 4 illustrate in side view, with a portion of the device removed, two different working positions for a moving part included in the device.
BEST MODE FOR CARRYING OUT THE INVENTION
In the following description, terms such as "right", "left", "upper", "lower"
REFERENCES:
patent: 3825162 (1974-07-01), Hubbard
patent: 4003647 (1977-01-01), Kuppens
patent: 4203335 (1980-05-01), Coffey
patent: 4251162 (1981-02-01), Krammerer et al.
patent: 4304345 (1981-12-01), Carlin
patent: 4412637 (1983-11-01), Berger
Levy Stuart S.
Sohacki Lynn M.
Telefonaktiebolaget L M Ericsson
LandOfFree
Tractor mechanism for printers does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tractor mechanism for printers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tractor mechanism for printers will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1657686