Patent Grant
7059595
The present invention relates generally to mail inserters and, more particularly, to enclosure feeders in an inserter.
Mail inserters have played a significant role among the labor saving devices available to businesses, which are engaged in the daily mailing of large numbers of pieces. Among the advantages of inserter usage has been the reduction in personnel required to process large quantities of outgoing mail. In a typical mail inserter, a plurality of enclosure feeders are used to release a plurality of enclosure materials or documents into the chassis of the inserter. The released documents are pushed downstream and collated into a stack. The stack is then inserted into an envelope in an insertion station. Inserters and enclosure feeders are known in the art. For example, Foster et al. (U.S. Pat. No. 4,418,515) discloses a mail inserter having a plurality of sloped trays, each of which carries a stack of documents, wherein one or more feed rollers are used to pick up a sheet of document at a time and release it into a chassis. Godlewski (U.S. Pat. No. 4,715,593) discloses a bottom stack feeder wherein a feeding mechanism having a plurality of feed rollers and pullout roller is used to pull out a sheet of stock items from the bottom of the stack in the feeding process.
The released documents are released from different feeders in the collation process. It is important that the released documents are fed evenly in that each document should be released onto the chassis with the leading edge substantially perpendicular to the releasing direction. However, the friction characteristics of the documents and the feeding mechanism sometimes render it difficult to achieve an even feeding. In an uneven feeding, the feed is skewed such that one side of the leading edge of the released document may move faster than the other side of the leading edge. Uneven feed may cause machine errors.
Thus, it is advantageous and desirable to provide a method and apparatus for controlling feeding of documents or enclosures in order to correct for the uneven feeding.
It is an objective to correct the skew of mail-related items in a mailing machine. The objective can be achieved by using a plurality of driving belts with openings to drive the items, and applying air pressure through the openings to change the friction force between a mail-related item and the driving belts if the skew exceeds predetermined value. According to the first aspect of the invention, a method for correcting movement of a plurality of items in a mailing machine, wherein the mailing machine has at least one driving mechanism for causing the items to move along a predetermined path. The method comprises the steps of:
detecting a skew of the items in the predetermined path, the skew being characterized such an item is positioned so that a leading edge of the item is tilted relative to the path and the leading edge in the first portion of the path is ahead of the leading edge in the second portion of the path, and
correcting the skew if the skew exceeds a predetermined value by applying differing air pressure from the first or second parallel path portions to the skewed item.
monitoring the movement of the items for detecting a skew of the items in the predetermined path, and
applying air pressure on the items for correcting the skew if the skew exceeds a predetermined value.
The mailing machine may comprise a plurality of enclosure feeders, each of which is used to release the mail-related items one at time, the method further comprising the step of
disposing a plurality of sensors at each enclosure feeder for sensing the leading edge of an item released by said each enclosure feeder in order to detect the skew.
Preferably, the sensors are photosensors having light emitters and light detectors.
Preferably, each of the enclosure feeders has a driving mechanism comprising at least two driving belts disposed on opposite sides of the predetermined path for driving the items via friction, and wherein the driving belts have openings for applying air pressure on the items in order to change the friction.
The air pressure can be negative or positive air pressure, or a combination of positive air pressure on one driving belt and negative air pressure on another driving belt.
According to the second aspect of the present invention, a driving mechanism for use in a mailing machine, wherein the driving mechanism comprises:
at least two driving belts, disposed on opposite sides of a predetermined path in the mailing machine, for causing mail-related items to move via friction along the predetermined path;
a sensing mechanism positioned relative to the predetermined path for detecting a skew in the items when the items are caused to move by the driving belts; and
an air pressure system for applying air pressure to the items to correct the skew if the skew exceeds a predetermined value.
Preferably, the driving belts have a plurality of openings so as to allow the air pressure to be applied on the items for changing the friction.
Preferably, the sensing mechanism comprises at least two photosensors for detecting arrival of the leading edge of items in order to determine whether the skew exceeds the predetermined value.
According to the third aspect of the present invention, there is provided a mail inserter, which comprises:
at least one feeder for releasing mail-related items for mail insertion, wherein the feeder comprises a driving mechanism for causing the items to move along a predetermined path;
a sensing mechanism positioned relative to the driving mechanism for detecting a skew in the items while the items are caused to move by the driving mechanism; and
an air pressure system for applying air pressure on the items for correcting the skew if the skew exceeds a predetermined value.
Preferably, the driving mechanism comprises at least two driving belts disposed on opposite sides of the predetermined path for driving the items via friction, said mail inserter further comprising:
a plurality of air conduits operatively connected to the air pressure system and the openings on the driving belts; and
a plurality of air valves disposed on the air conduits to control the air pressure applied on the items for correcting the skew.
According to the fourth aspect of the present invention, a movement control system for use in a mailing machine, wherein the mailing machine comprises a driving mechanism for moving mail-related items along a predetermined path. The control system comprises:
a sensing mechanism, positioned relative to the predetermined path, for detecting a skew of the items in the predetermined path; and
an air pressure system, operatively engaged with the driving mechanism, for applying air pressure on the items in order to correct the skew if the skew exceeds a predetermined value.
Preferably, the driving mechanism comprises at least two driving belts disposed on opposite sides of the predetermined path for driving the mail-related items via friction, the driving belts having a plurality of openings, and wherein the air pressure system comprises:
a plurality of air conduits operatively connected to the openings on the driving belts; and
a plurality of air valves disposed on the air conduits to control the air pressure applied on the items for changing the friction.
The present invention will become apparent upon reading the description taken in conjunction with
In order to achieve even feeding in an enclosure feeder in a mail inserter, the present invention uses two or more pairs of photosensors to determine whether the feed is skewed. As shown in
In order to determine the skew angle of the arriving enclosure document 22 and to straighten the moving path of subsequent enclosure documents, the sensing signals 88 from the photosensing module 30 are conveyed to a control module 90, as shown in
It should be noted that the enclosure documents in a stack are usually identical to each other. However, the friction between one side of the enclosure document and the driving mechanism may be different from the friction between the other side of the enclosure document and the driving mechanism. For example, one side of the enclosure document may be printed with a picture while the other side printed with text, the side with the picture may have less friction than the other side. As a result, the leading edge of the “picture” side may trail behind the leading edge of the other side. Preferably, an air pressure, negative or positive, is used to equalize the friction on both sides of the enclosure document.
According to the present invention, a valve manifold 250 of a vacuum system 200 is used to create such a friction force adjustment to the driving mechanism 100. As shown in
Preferably, the vacuum port of the pneumatic venturi is connected to a manifold below the feed belts to transmit a difference of air pressure through the feed belts. The exhaust of the venturi can be fed though a valve, which when shifted, pressurizes the manifold below the feed belts. The mechanism is present on both sides of the driving mechanism, allowing left and right hand control of the drive.
Preferably, when the control module senses the skew of the enclosure documents departing the driving mechanism, it checks the skew against an error threshold. If the skew exceeds the error threshold, it sends a control signal 92 to the valve manifold in order to activate the corrective system. For example, if the right side of an enclosure document leads the left side, an increase in the friction at the belt-enclosure interface on the left side is necessary to reduce the slippage. But it is also possible to reduce the friction at the interface on the right side separately or concurrently. This can be accomplished by activating the vacuum on the left side and blocking or pressuring the pneumatic venturi exhaust on the right side. The opposite skew can be controlled conversely. When the skew is below the error threshold, the driving mechanism may be able to return to normal operation. The error threshold, can be set between 5 to 15 degrees, for example.
In sum, positive pressure or negative pressure can be applied only on one side of the driving mechanism to correct for the skew of enclosure documents. However, opposite pressures can also be concurrently applied to the enclosure documents. As shown in
It should be noted that the present invention has been described in conjunction with an enclosure feeder. However, the same principle can also be applied to an envelope feeder in a mail inserting machine or the like.
Thus, although the invention has been described with respect to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and various other changes, omissions and deviations in the form and detail thereof may be made without departing from the scope of this invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4651984 | Emrich | Mar 1987 | A |
| 5634636 | Jackson et al. | Jun 1997 | A |
| 5921544 | Benedict | Jul 1999 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20050067767 A1 | Mar 2005 | US |
