Sheet feeding or delivering – Feeding – Separators
Reexamination Certificate
2000-01-24
2001-08-07
Bollinger, David H. (Department: 3651)
Sheet feeding or delivering
Feeding
Separators
C271S121000, C271S124000, C271S167000
Reexamination Certificate
active
06270069
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to methods and apparatus for handling flat articles, such as mixed mail, and more particularly to a mechanism for resolving doubles at the output from a singulation mechanism of such a system and to a method for the use of such mechanism.
BACKGROUND OF THE INVENTION
In systems for handling mixed mail or other flat articles, which may or may not be of a uniform size, the articles are frequently stacked on edge and passed through a singulation mechanism at the beginning of the operation. However, particularly where there are significant variations in the size, thickness and weight for the articles being singulated, the singulator will it from time to time pass two or more pieces of mail or other articles simultaneously, a smaller article for example piggy-backing on a larger article being singulated. This problem, which is commonly referred to as doubles or multiple feeds, if left unresolved, can possibly lead to missorts, damage to the articles, rejects or jams in downstream parts of the system. While many techniques have been employed in the past to resolve such doubles, particularly in mail handling systems, the variations in size, weight and thickness of mixed mail make doubles very difficult to resolve. For example, one specification for a mixed mail handling system requires handling mail vary in size from 4″×4″ or 3.5″×5.0″ to 15″×15″, weights from a 0.03 ounces to six pounds and thickness from 0.007″ up to 1.25 inches. Further, some of the larger pieces may be soft covered magazines, catalogs, telephone books or the like which are bound on only one edge, further complicating the singulation and doubles resolving process. Mechanisms for successfully resolving doubles at the output of a singulator in a system handling articles of mixed size, thickness and weight with variations on the order of those indicated above do not currently exist.
SUMMARY OF THE INVENTION
In accordance with the above, this invention provides a method and apparatus for resolving doubles exiting a singulation mechanism which takes advantage of the fact that the doubled piece will typically be a thinner, lighter piece. The invention thus provides, in a system for passing a singulated flat article in a downstream direction from a singulation mechanism to a takeaway mechanism, a doubles resolver mechanism which includes a doubles resolver head having negative pressure selectively applied to an operative surface thereof, and a mount for the head which mount positions the operative surface of the head against a side of each article which is opposite the side against which drive is applied by the singulation and takeaway mechanisms, the mount pressing the head against each article, as the article passes between the singulation mechanism and the takeaway mechanism, with a force which is substantially constant regardless of the thickness of the article. The mount preferably includes a gas spring operating on the head to apply the constant force thereto. For preferred embodiments, the gas spring is a pneumatic cylinder, a controlled positive pneumatic pressure source applying gas pressure to the cylinder to control the constant force being applied thereby. The mount may also include a stop which limits movement of the head against the force being applied by the gas spring. The head may also be attached to at least one shaft mounted in a bearing, the shaft moving in the bearing to facilitate movement of the head parallel to the direction of the force applied to the article. For at least one embodiment of the invention, the operative surface of the head is at a slight angle to the downstream direction. For another embodiment, the head is mounted to rotate from a position with its operative surface substantially parallel to the direction of article movement, or at a slight angle thereto, to a position at a greater angle to such direction as each article passes under the head. For this embodiment, a passive valve may be provided which reduces the negative pressure applied to the operative surface of the head as the angle for the operative surface increases, the valve substantially cutting off the negative pressure when the operative surface is an at a selected maximum angle for an illustrative embodiment. The head separates and holds a doubled article piggybacking on an article passing from the singulation to the takeaway mechanism, negative pressure normally being applied to the operative surface, but being cut off when a doubled article is detected as being held by the head. For preferred embodiments, the articles on which the doubles resolver mechanism is used are mixed mail.
The invention also includes a method for resolving doubles in a system of the type previously indicated, which method includes mounting a doubles resolver head having negative pressure applied to an operative surface thereof between the singulation mechanism and the takeaway mechanism, with the side of each article opposite that to which drive is applied by the singulation and takeaway mechanisms in contact with the operative surface of the head as each article passes thereunder; and pressing the head against each article with a force which is substantially constant regardless of the thickness of the article. The mounting step may mount the head with the operative surface angled slightly away from the direction of article movement or the head may be mounted to rotate from a position with its operative surface substantially parallel to the direction of article movement to a position at a slight angle to such direction as each article passes under the head. In the latter case, the negative pressure applied to the operative surface of the head may be reduced as the angle for such operative surface increases, and may be substantially cut off when the operative surface is at a selected maximum angle to the direction of article movement. The head preferably separates and holds a doubled article, negative pressure normally being applied to the operative surface and being cutoff when a doubled article is detected as being held by the head. When the negative pressure is cut off, the doubled article is preferably adjacent to the drive for at least one of the singulation or the takeaway mechanism and such drive is then operated to clear the doubled article. Finally, the invention includes a doubles resolver head having negative pressure normally applied to an operative surface of the head, and a mount for the head which mount positions an operative surface of the head against the non-driven side of each article as the article passes between the singulation and takeaway mechanisms, the head separating and holding a doubled article, and the negative pressure being cut off when a doubled article is detected as being held by the head.
The foregoing and other objects, features and advantages of the invention will be apparently from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings, the same reference numerals being used for common elements in the various drawings.
REFERENCES:
patent: 3126201 (1964-03-01), Rehm
patent: 4357007 (1982-11-01), Mens Franciscus et al.
Blackwell Wayne
Cera George
Taylor Lou
LandOfFree
Doubles resolver mechanism and method for the use thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Doubles resolver mechanism and method for the use thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Doubles resolver mechanism and method for the use thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2486989