Conveyors: power-driven – Conveyor section – Having means to enhance the friction or adherence between...
Reexamination Certificate
1999-04-09
2001-04-17
Olszewski, Robert P. (Department: 3652)
Conveyors: power-driven
Conveyor section
Having means to enhance the friction or adherence between...
C198S813000, C198S841000
Reexamination Certificate
active
06216848
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to the field of article handling and, more particularly, to the field of handling articles for transporting or conveying during various industrial processing.
BACKGROUND OF THE INVENTION
Over the years, various article, e.g., mail, feeding, handling, sorting, and transporting systems have been developed for feeding, handling, sorting, and transporting pieces of mail. Within the field of article handle, one source of bottleneck and other handling problems has been the transporting of the articles along a surface. For example, know article conveying systems often have unstable platforms and may have an arcuate sectional profile whereby medial portions of a conveyor belt are often arcuate. This unstable platform and arcuate profile, however, can make printing on a surface of an article, e.g., a mail item, paper, or cardboard material, difficult. The results can be a distortion in the surface or ink as the ink from a printer is being applied. This, in turn, can cause irregularities within the printed image, poor image quality, and poor image resolution. Accordingly, there is a need for a more stable conveyor system which allows articles to be handled and transported effectively and allows printing on the surface of the article with minimal irregularities, high quality, and high resolution in the printed image.
SUMMARY OF THE INVENTION
In view of the foregoing background, the present invention advantageously provides a vacuum table conveying apparatus and associated methods which provide a stable conveying platform for articles mounted thereon. The present invention also advantageously provides a vacuum table conveying apparatus having a substantially flat belt conveying surface so that printer heads can easily be positioned closely adjacent the flat surface to thereby enhance image quality and resolution of images printed on surfaces of articles being conveyed therealong. The present invention additionally provides a vacuum table conveying apparatus and associated methods which has a high volume of air under a low vacuum pressure to enhance the holding power and the uniformity of the conveying of articles positioned thereon. The present invention further advantageously provides a vacuum table conveying apparatus and associated methods which allows air to move with the articles positioned thereon at substantially the same speed and which has a vacuum chamber substantially impervious to leaks.
More particularly, the present invention provides a vacuum table conveying apparatus which preferably includes a frame, a vacuum chamber positioned to extend along an upper portion of the frame, vacuum forming means positioned in fluid communication with the vacuum chamber to apply a low vacuum with a high volume of air to the vacuum chamber, and at least one vacuum belt overlying the vacuum chamber. The at least one vacuum belt preferably has a plurality of openings extending through upper and lower surfaces thereof so that vacuum from the vacuum chamber extends through the plurality of openings and applies to articles mounted on the upper surface of the at least one vacuum belt.
The vacuum forming means, for example, is preferably provided by a vacuum source which has a plurality of fans positioned in fluid communication with the vacuum chamber for applying a low vacuum with a high volume of air to the vacuum chamber. The apparatus also preferably has a plurality of spaced-apart rollers mounted to the frame, and the at least one vacuum belt is preferably mounted to and extending between the plurality of spaced-apart rollers and overlying the vacuum chamber. The apparatus additionally preferably has at least one drive connected to the frame for driving the plurality of rollers to thereby drive the at least one vacuum belt mounted thereon and convey articles mounted on the at least one vacuum belt in a predetermined direction of travel.
For enhanced stability of the table platform, e.g., belt and upper portions of the frame, each of the plurality of spaced-apart rollers preferably includes a roller channel formed in an outer surface of the roller. The at least one vacuum belt, in turn, preferably includes a belt stability protrusion extending outwardly from a medial portion of a lower surface of the at least one vacuum belt and positioned within each of the roller channels to thereby provide enhanced stability in the at least one vacuum belt when being driven by the plurality of rollers.
A vacuum table conveyor belt is additionally provided according to the present invention and preferably is formed by a combination of a first low friction web material layer, a second plastic material layer overlying the first low friction web material, and a belt stability protrusion connected to and extending outwardly from a medial portion of the first low friction web material layer. The belt stability protrusion is preferably positioned to abuttingly contact a drive roller and preferably has peripheries having a vertical sectional view thereof which define a substantially frusto-conical shape or another substantially V-shape.
The present invention also includes a method of conveying articles. The method preferably includes providing a low vacuum and high volume air source in fluid communication with a vacuum chamber, positioning at least one conveyor belt having a plurality of openings extending therethrough to overlie the vacuum chamber and in fluid communication with the vacuum source, and positioning a plurality of articles on the at least one conveying belt to be held in position by the vacuum applied through the plurality of openings from the vacuum chamber.
The present invention further provides a method of printing on conveyed articles. This method preferably includes providing a low vacuum and high volume air source in fluid communication with a vacuum chamber, positioning at least one substantially flat conveyor belt having a plurality of openings extending therethrough to overlie the vacuum chamber and in fluid communication therewith, positioning a plurality of articles on the at least one conveying belt to be held in position by the vacuum applied through the plurality of openings from the vacuum chamber, driving the at least one conveying belt in a predetermined direction, sensing the presence of articles positioned on the at least once conveyor belt, and positioning a head of a printer closely adjacent an upper surface of the substantially flat conveyor belt.
The combination of additional table platform stability, the enhanced vacuum which provides a uniform vacuum force and a strong holding force, and the substantially flat belt surface allow the vacuum table conveying apparatus to greatly enhance performance and handling quality of items such as mail, paper, books, or other material being transported therealong. The apparatus, for example, can advantageously be used for high speed transport and printing applications such as labels or other indicia on mail items. In such applications, high resolution ink jet requires an extremely stable platform, both in vertical and horizontal planes, as well as a constant speed. The paper or mail items, in turn, need to move on a substantially flat surface and very close to the ink jet printer head. If the surface is not substantially flat, then the particles or drops of ink being emitted from the ink jet head tend to be elliptical in formation and cause poor resolution or other quality problems.
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Allen Dyer Doppelt Milbrath & Gilchrist, P.A.
Chin Paul T.
Olszewski Robert P.
Profold, Inc.
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