Conveyor mechanism and a method for adjusting a conveyor mechanism

Patent metadata

Field	Value
Publication number	US-9850086-B2
Application number	US-201514943823-A
Country	US
Kind code	B2
Filing date	Nov 17, 2015
Priority date	Nov 18, 2014
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

The present invention provides a conveyor mechanism for conveying sheets. The conveyor mechanism comprises a movable conveyor body, a drive mechanism, and an adjustment system configured to detect and correct skewing of the conveyor body, comprising one or more markers provided on or in the conveyor body, a sensor arrangement for detecting each marker at two or more discrete positions, and a processor to determine the skewing of the conveyor body. The conveyor body and the drive mechanism of the conveyor mechanism are mounted on a movable conveyor frame, and the adjustment system includes a frame shifting device comprising one or one or more actuator for shifting or moving the conveyor frame relative to a fixed framework. The invention also provides a related method of correcting skewing in a conveyor mechanism for conveying sheets along a transport path.

First claim

The invention claimed is:

1. A suction belt conveyor mechanism for conveying a plurality of sheets along a transport path in a printing system, wherein the conveyor mechanism comprises:
a movable endless suction belt member comprising perforations for communicating an under-pressure to an outer surface of the endless suction belt member on which the sheets are supported, wherein the under-pressure holds the sheets in a fixed position on the endless suction belt member as the endless suction belt member is moved to convey the sheets along the transport path;
a drive mechanism comprising a first roller and a second roller, which rollers support and drive a movement of the endless suction belt member to convey the sheets along the transport path; and
an adjustment system configured to detect and correct skewing of the endless suction belt member as the endless suction belt member conveys the sheets along the transport path, the adjustment system comprising:
at least one marker provided on or in the endless suction belt member;
a sensor arrangement for detecting each marker at at least two discrete positions spaced apart from one another by a predefined distance along a length of the transport path, wherein the sensor arrangement comprises:
a first sensor device provided at a first position for detecting each marker; and
a second sensor device provided at a second position for detecting each marker,
wherein the first position and the second position are spaced apart from one another by the predefined distance in a transport direction of the transport path; and

a processor for processing data provided by the sensor arrangement to determine the skewing of the endless suction belt member,
wherein the first roller and the second roller of the drive mechanism are mounted on a movable conveyor frame, and
wherein the adjustment system comprises a frame shifting device, the frame shifting device comprising at least one actuator for moving the moveable conveyor frame relative to a fixed framework, such that the endless suction belt member is moved to correct the detected skewing,
wherein the at least one marker comprises a plurality of markers which are spaced apart along a length of the endless suction belt member, wherein each marker is fixed with respect to the endless suction belt member, and wherein each marker comprises its own characteristic form and/or each adjoining pair of said plurality of markers are spaced apart from one another along the length of the endless suction belt member at a unique spacing, such that each marker is uniquely identifiable by the sensor arrangement.

2. The suction belt conveyor mechanism according to claim 1 ,
wherein the endless suction belt member is mounted on the movable conveyor frame.

3. The suction belt conveyor mechanism according to claim 1 ,
wherein the at least one actuator is arranged for driving a pivoting or rotational movement of the conveyor frame with respect to a reference axis, such that the endless suction belt member is driven in a pivoting or rotational movement with respect to the reference axis.

4. The suction belt conveyor mechanism according to claim 3 , wherein the at least one actuator is arranged for pivoting the conveyor frame with respect to the reference axis,
wherein movement of the conveyor frame is determined based on the data from the sensor arrangement in relation to the detected skewing of the conveyor frame to correct for the detected skewing, and
wherein the processor is configured to analyse the data from the sensor arrangement to determine the skewing based on a deviation of any of the plurality of markers with respect to a skew sensing axis and to control operation of the frame shifting device to correct the skewing by pivoting the conveyor frame to a required degree about the reference axis, when the processor has determined a skewing of the endless suction belt member based on a deviation of any of the plurality of markers with respect to the skew sensing axis.

5. The suction belt conveyor mechanism according to claim 1 ,
wherein each marker preferably comprises an aperture in the endless suction belt member.

6. The suction belt conveyor mechanism according to claim 1 ,
wherein the first position of the first sensor device and the second position of the second sensor device are provided on a frame member which provides the predefined distance, wherein the frame member is formed of a material substantially insensitive to temperature change.

7. The suction belt conveyor mechanism according to claim 1 ,
wherein the first sensor device has a first skew sensing axis at the first position; and
wherein the second sensor device has a second skew sensing axis at the second position, the first and second skew sensing axes extending generally parallel to the transport path,
wherein the first and second sensor devices are respectively configured to detect each marker with respect to the first and second skew sensing axes.

8. The suction belt conveyor mechanism according to claim 7 ,
wherein the processor is configured to determine a skewing of the endless suction belt member from a deviation of any of the markers with respect to the first or second skew sensing axes between the first and second sensor devices.

9. The suction belt conveyor mechanism according to claim 1 ,
wherein the endless suction belt is substantially rigid.

10. The suction belt conveyor mechanism according to claim 9 ,
wherein the endless suction belt is comprised of steel.

11. A printing system comprising the suction belt conveyor mechanism according to claim 1 for conveying sheets of print medium,
wherein the adjustment system is configured to determine and correct skewing of the endless suction belt member which holds the sheets in an image forming device for printing an image on the sheets.

12. The mechanism according to claim 1 , wherein a skew sensing axis of the sensor arrangement extends between the first and second positions, and wherein the processor is configured to analyze the data from the sensor arrangement to determine the skewing based on a deviation of any of the plurality of markers with respect to the skew sensing axis.

13. A method of adjusting a suction belt conveyor mechanism to correct skewing of a movable endless suction belt member which conveys sheets along a transport path, the conveyor mechanism comprising the endless suction belt member, the endless suction belt member comprises perforations for communicating an under-pressure to an outer surface of the endless suction belt member on which the sheets are supported, wherein at least one marker is provided on or in the endless suction belt member and distributed along a length of the endless suction belt member, a drive mechanism comprising a first roller and a second roller which rollers support and drive a movement of the endless suction belt member to convey the sheets along the transport path and a movable conveyor frame, wherein the first roller and the second roller of the drive mechanism are mounted on the movable conveyor frame, the method comprising the steps of:
conveying the sheets along the transport path via the endless suction belt member while providing the under-pressure to the outer surface of the endless suction belt member to hold the sheets in a fixed position on the endless suction belt member;
sensing with a sensor arrangement each of the at least one markers at a first position positioned along the transport path;
sensing with the sensor arrangement each of the at least one markers at a second position positioned along the transport path, wherein the first position and the second position are spac

Assignees

• Oce Tech Bv

Inventors

• Smeyers Johannes H L
• Albers Antonius G H
• Jacobs Roy H R
• Janssen Cornelius M F
• Winarto Reinoldus F
• Clevers Ernest J J

Classifications

• B65H2404/2693

  Arrangement of belts on movable frame · CPC title

• B65H2553/82

  with regard to the direction of transport of the handled material · CPC title

• B65H7/08

  responsive to incorrect front register · CPC title

• B65H2801/15

  Digital printing machines · CPC title

• B65H2553/41

  Photoelectric detectors · CPC title