High Speed Sheet Feeder Sheet Spacing System and Method
A document system and method of moving documents of a stack. The system operates to move documents by rotating a feed wheel and a transport wheel to move a document in a feed direction. The space between documents is maintained by controlling the speed of the feed wheel and the transport wheel independently.
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The present invention relates to document and sheet feeding devices generally, and more particularly to document and sheet feeding devices that are capable of continuously feeding sheets to be sorted and further processed at high speeds, and more particularly still to a sheet feeding system and method for improving the speed and efficiency of such system by enabling more precise spacing between individual sheets in a set and between separate sets.
The present invention will be more fully understood from the detailed description and the accompanying drawings, wherein:
The following detailed description is of the best mode or modes of the invention presently contemplated. Such description is not intended to be understood in a limiting sense, but to be an example of the invention presented solely for illustration thereof, and by reference to which in connection with the following description and the accompanying drawings one skilled in the art may be advised of the advantages and construction of the invention.
As illustrated in
Encoder 28 is operably connected to the shaft of transport wheel 24, and is used to measure the length of each sheet or document 16 being fed. Encoder 28 may be a standard shaft encoder with 600 pulse per revolution or other rotary pulse generator. A second electronic document sensor 30, also referred to herein as leading edge sensor or “Sensor B”, is situated on the downstream side of transport wheel 24, between transport wheels 24 and 32. Similar to “Sensor A” 22, “Sensor B” 30 is also advantageously an optical sensor that generates an output signal whenever a document is detected to be passing in the path of the sensor, but may be another type of sensor such as an ultrasonic sensor. Sensor B 30 is operably connected to encoder 28 such that the output signal of Sensor B activates encoder 28 to perform various functions such as resetting the encoder value to zero, initiating sheet measurement, and performing a check of the calculated encoder value. As explained in greater detail below, the combination of leading edge sensor 30 and encoder 28 connected to transport wheel 24 exactly measures the length of each sheet 16 as it is fed by the feeder, which information is used to configure the system to provide the desired separation between consecutive sheets being fed.
Transport wheel 32 carries sheets or documents 16 passed from transport wheel 24 to an accumulation area or accumulator 29, where a plurality of individual sheets or documents 16 intended to be grouped into a set or stack 36 is accumulated prior to be fed further down the feed track for further processing such as to a folding device for folding, and then to an enveloping machine and/or other processing apparatus in a manner known to those skilled in the art. Once a set has been accumulated, the next set to be accumulated is signaled or initiated.
A preferred manner of operation of system 10 will now be described with reference to the detailed steps in the flowcharts of
Referring again to
Referring now to
Once the speed of Servo #1 has been reduced from Speed #2 to Speed #1 in Step 230 as triggered by the unblocking of Sensor A in Step 220, in Step 240, if the value measured by encoder 28 is below a preset value, encoder 28 continues measuring. However, once the value measured by encoder 28 is at or above such pre-set value, which is also referred to as “Stop Point Z,” in Step 250 Servo #1 26 is stopped, stopping transport wheels 24 and 32. Feed wheel 18 continues to rotate, however, and a second sheet or document 16b is conveyed by feed wheel 18 from stack 14 in feed direction 15, until it is blocking Sensor A or “Alignment Point X” (Step 260), which triggers Servo #2 and feed wheel 18 to stop again (Step 270), similar to Steps 120 and 130 described above. This is illustrated diagrammatically in
Referring next to
Second sheet or document 16b is fed by the rollers in the feed direction 15 until Sensor B is blocked by the sheet (see
Referring now to
Referring now to
In contrast, at certain times during the feed process of the present invention, Servo #2 is directed by the system to operate at a speed considerably slower than the speed of Servo #1 during the such feed process. By Servo #1 driving the feed wheel 18 to turn at such considerably slower speed allows for precise control of the feed process, and is designed to create a larger gap between sets, and also correctly positions the next piece from the feeder. In addition, the system 10 also directs a change in speed of Servo #1 and Servo #2 from Speed #1 to Speed #2, where the speed of Servo #1 is increasing while Servo #2 is decreasing in speed. This also allows for even greater control of the spacing between sheets both in the same set and between the last sheet in the set being accumulated and the next sheet in the set to be accumulated.
In U.S. Pat. No. 6,533,264 issued to M. N. Tranquilla on Mar. 18, 2003 entitled “Constant Space Document Feeder,” discloses an mechanism for generating a predetermined feed spacing between consecutive documents that is independent of the document length, wherein the feed wheel speed is reduced to an adjustment speed for an adjustment time period, and then is increased after the adjustment time period has expired. The adjustment speed and time period are determined by an adjustment module, wherein the trailing edge of a first document and leading edge of a second document are detected, which gives an initial feed spacing, and then the feed wheel speed is adjusted to give a predetermined or desired spacing. Tranquilla does not achieve the amount of control over the feed system that is achieved with the multiple speed system of the present invention.
U.S. Pat. No. 7,635,127 issued to K. Kuse on Dec. 22, 2009, entitled “Sheet Feeding Apparatus,” discloses a sheet feeder including rotation speed controller for the adjusting the speed of a separation roller used to feed sheets from a stack between a first speed and a second speed. In particular, the first sheet is fed at a slower rotation speed than subsequent sheets. The primary purpose of the Kuse patent is to prevent leading edge folding of a document during feeding during copying or the like using an automatic document feeding apparatus.
While the present invention has been described at some length and with some particularity with respect to the several described embodiments, it is not intended that it should be limited to any such particulars or embodiments or any particular embodiment, but it is to be construed with references to the appended claims so as to provide the broadest possible interpretation of such claims in view of the prior art and, therefore, to effectively encompass the intended scope of the invention. As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.
Claims
1. A document system for a document, including:
- a feed servo controller;
- a feed servo motor controllable by the feed servo motor;
- a feed wheel adjustably rotatable by the feeder servo motor to move the document in a feed direction;
- a feed sensor downstream of the feed wheel in the feed direction and capable of detecting the presence of the document;
- a transport servo controller;
- a transport servo motor controllable by the transport servo controller;
- transport wheels downstream of the feed wheel and the feed sensor in the feed direction, wherein at least one of the transport wheels is adjustably rotatable by the transport servo motor to continue to move the document in the feed direction;
- a transport sensor downstream of one of the transport wheels in the feed direction and capable of detecting the presence of the document;
- an encoder operably connected to a transport wheel to measure the length of the document; and
- wherein the rotational speed of the feed wheel and the rotational speed of the transport wheels are controllable independently.
2. The system of claim 1, further including a stack of documents.
3. The system of claim 1, including two transport wheels connected together for rotation, one of the transport wheels capable of driving the other transport wheel.
4. The system of claim 1, further including an accumulator for collecting the document after being fed by the transport wheels.
5. The system of claim 1, wherein more than on transport wheel is adjustably rotatable by the transport servo motor.
6. The system of claim 1, further including a processor and wherein the feed sensor produces an output signal indicative of the detection of the document.
7. The system of claim 6, wherein the feed servo motor is controlled by the feed servo controller depending on the output signal from the feed sensor.
8. The system of claim 1, further including a processor and wherein the transport sensor produces an output signal indicative of the detection of the document.
9. The system of claim 8, wherein the transport servo motor is controlled by the feed servo controller depending on the output signal from the transport sensor.
10. The system of claim 1, wherein the transport sensor is operably connected with the encoder such that an output signal of the transport sensor activates the encoder.
11. The system of claim 1, wherein the feed wheel is rotatable at multiple predetermined speeds.
12. The system of claim 1, wherein the transport wheels are rotatable at multiple predetermined speeds.
13. The system of claim 1, the document further including a visual code, the system further including a scanner to detect the visual code.
14. A method of moving documents of a stack, including:
- rotating a feed wheel to move a document in a feed direction;
- rotating a transport wheel downstream of the feed wheel to continue to move the document in the feed direction;
- rotating the feed wheel and the transport wheel to move additional documents; and
- maintaining a space between the documents moving in the feed direction by controlling the speed of the feed wheel and the speed of the transport wheel independently.
15. The method of claim 14, wherein rotating the feed wheel further includes rotating the feed wheel at a first feed speed to initiate moving a document in the feed direction to a first alignment point.
16. The method of claim 14, further including:
- rotating the feed wheel at a first feed speed;
- detecting the presence of a document at a first alignment point and then stopping the feed wheel;
- rotating the feed wheel at a second feed speed that is faster than the first speed;
- rotating the transport wheel at a first transport speed that is the same as the second feed speed; and
- wherein maintaining the space between documents includes: determining if the document is at a predetermined position along the feed direction; and if the document is not at the predetermined position, adjusting the speed of at least one of the feed to move the next document slower and wheel and the transport wheel to move the document faster.
17. The method of claim 16, wherein adjusting the speed of at least one of the speed wheel and the transport wheel includes at least one of:
- decreasing the speed of the feed wheel to either the first feed speed or a third feed speed that is slower than the first feed speed and slower than the second feed speed; and
- increasing the speed of the transport wheel to a second transport speed.
18. The method of claim 16, wherein adjusting the speed of at least one of the speed wheel and the transport wheel is done after the document is past the feed wheel.
19. The method of claim 16 wherein determining if the document is at a predetermined position includes measuring the length of a document to pass the predetermined position.
20. The method of claim 16, further including:
- determining if the document has moved past the first alignment point; and
- if the document has moved past the first alignment point, rotating the feed wheel at the second feed speed and rotating the transport wheel at the first transport speed.
21. The method of claim 14, including:
- determining the number of documents to move past the predetermined position;
- if the number of documents is equal to or greater than a set count value: stopping the rotation of the transport wheel; rotating the feed wheel at the first feed speed to move a document to a first alignment point; and detecting the presence of a document at the first alignment point and then stopping the feed wheel.
22. The method of claim 14, including:
- determining the number of documents to move past a predetermined position;
- measuring the length of a document that has passed the predetermined location;
- if the number of documents is less than a set count value, determining if a document is located at a first alignment point;
- if no document is detected at the first alignment point: rotating the feed wheel at the second feed speed; and rotating the transport wheel at the first transport speed;
- determining if a document is located at the predetermined location;
- if no document is detected at the predetermined location, determining if the measured length of the document is correct; and
- if the measured length of the document is incorrect, initiating a system error routine and stopping both the feed wheel and the transport wheel.
23. The method of claim 22, wherein:
- the documents include a visual code; and
- if no document is detected at either the first alignment point or the predetermined location and if the measured length of the document is correct, scanning the visual code on a document to determine if a set error occurred;
- if a set error occurred, initiating a system error routine and stopping both the feed wheel and the transport wheel.
25. The method of claim 14, further including rotating the feed wheel at the second feed speed and rotating the transport wheel at the first transport feed after a document passes the first alignment point.
Type: Application
Filed: Mar 8, 2013
Publication Date: Mar 27, 2014
Applicant: SENSIBLE TECHNOLOGIES, L.L.C. (Austin, TX)
Inventor: SENSIBLE TECHNOLOGIES, L.L.C.
Application Number: 13/791,347
International Classification: B65H 7/20 (20060101); B65H 7/02 (20060101); B65H 5/06 (20060101);