Sheet feeding or delivering – Feeding – Separators
Reexamination Certificate
2000-02-29
2001-11-20
Skaggs, H. Grant (Department: 3651)
Sheet feeding or delivering
Feeding
Separators
C271S121000
Reexamination Certificate
active
06318717
ABSTRACT:
DESCRIPTION
1. Technical Field
The present invention relates to a document feeder and in one aspect relates to a document feeder having a singulator which prevents more than one document from being fed at a time.
2. Background
In recent years, automated equipment has been developed for processing large volumes of documents (e.g. letters, postcards, checks, etc.). For example, equipment is currently available which takes stacks of documents and sorts the documents into individual pockets. The documents are picked off the stack by a singulator which feeds the document a reader (e.g. optical character reader or bar code reader) which reads some indicia on the document (e.g. Zip Code) and generates a signal representative thereof. This signal in turn, is processed by a computer which directs that particular document to a designated sort pocket in a “stacker section” of the equipment.
For such equipment to function at maximum efficiency, the documents must be fed one at a time with “multiple feeds” held to a minimum. That is, if more than one document is picked off by the singulator and fed into the equipment at the same time, numerous problems arise; e.g. jamming, hence possible damaging, of the multi-fed documents, failure to properly process all of the documents, etc. Therefore, the document feeder or singulator for such equipment must be capable of picking-off a single document from a stack and then feeding only that document into the equipment for individual processing.
There are several known singulators which have been proposed for this purpose. Some of these operate continuously to feed a steady supply of single documents through the equipment, e.g. see , U.S. Pat. Nos. 4,030,722 and 4,038,555 while others operate to feed a single document on demand. Probably the most widely used type of singulator used in present day document processors is one having (a) one or more forwardly-driven rollers which engage and advance a single document from the front of a stack of documents and (b) a reverse-driven roller which prevents additional documents from being fed into the equipment along with the single document; e.g. see In U.S. Pat. Nos. 3,825,248, 4,522,385, and 4,884,796.
While these types of singulators have worked well in the past, those skilled in this art will recognize that they can still experience significant multi-feeds problems in sorting certain stacks of documents (e.g. mail such as interspersed postcards, letters, “flats”, etc.). That is, it is difficult to maintain the proper adjustment between the forward-driven roller and the reverse-driven roller to guard against multi-feeds when a stack of documents is being sorted wherein the size and/or thickness of the documents in the stack may vary significantly.
Since the feeding of “doubles” or “multi-feeds”, even if only occasionally, seriously affects the overall efficiency of the processing/sorting equipment, it is vitally important that the singulator used for such equipment be as near perfect in this respect as possible. Accordingly, it follows that any improvement in the reduction of multi-feeds of documents in equipment of this type can significantly improve the operating efficiency of the equipment.
SUMMARY OF THE INVENTION
The present invention provides a document feeder for a document processing machine. Basically the feeder comprises a deck which includes a magazine for receiving a stack of documents and a pick-off means for picking off the documents one at a time. The pick-off means is comprised of a pick-off roller which is driven in a forward direction to engage the first document of said stack of documents and move said first document towards a transport.
A stripper means is positioned downstream from the pick-off means and engages any additional documents (i.e. multi-feeds) that may be inadvertently pulled off the stack along with the first document to thereby prevent further movement of the additional documents until the first document is delivered to the transport. The stripper means of the present invention is comprised of a first stripper assembly and a second stripper assembly both of which are mounted one above the other for independent rotation about a common vertical pivot point on said deck.
The first stripper assembly is comprises a first arm which, in turn, has a first end rotatably mounted on a shaft positioned at the common pivot point on said deck. The first arm has a means at a second end for engaging and restricting further movement of any additional documents with the single document being fed through the singulator. The second stripper assembly is comprised of basically the same structure as the first stripper assembly except the arm of the second stripper assembly is shorter (e.g. from about ⅛ inch to about ¾ inch) than the arm of the first stripper section. Preferably, the longer-arm assembly is positioned above the shorter-arm assembly.
Both the first and the second stripper assemblies are biased inwardly by a spring or the like towards the documents being fed so that each assembly can independently move outward and adjust to different sizes and/or thickness of documents as they are fed through the singulator. Also, individual dampening means (e.g. dash-pots) are provided for each of the assemblies to dampen the movement of the stripper assemblies as they move inward away from the documents. This alleviates the bouncing action caused when a document engages a respective stripper assembly, thereby maintaining better contact with the documents and resulting in a better stripping action to prevent multi-feeds.
By having the arm of one stripper assembly longer than the arm of the other stripper assembly, the short-arm assembly will contact a multi-fed envelope and slow it down before the envelope is contacted and stopped by the longer-arm assembly. This results in improved “stripping” of potential multi-feeds.
REFERENCES:
patent: 3210073 (1965-10-01), Godlewski
patent: 3825248 (1974-07-01), Friend
patent: 4522385 (1985-06-01), Stefansson
patent: 4884796 (1989-12-01), Daboub
patent: 5109987 (1992-05-01), Daboub et al.
patent: 2244264 A (1991-11-01), None
patent: 2029377 A (1980-03-01), None
patent: 7700049 (1978-07-01), None
Ayala Federico
Daboub Brent A.
Daboub Henry A.
Faulconer Drude
National Presort, Inc.
Skaggs H. Grant
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