NSF-Funded Student Design Projects:
Paper Counter and Dispenser

Designers: Vincent Alexander, Michael D. Kresbaugh, Vincent Palazzolo, and Jamie Waldrup
Client Coordinator: Ms. Lynne Hagmann, Western Wayne Skills Center
Supervising Professor: Robert Erlandson, Ph.D.
Department of Electrical and Computer Engineering
Wayne State University, Detroit, MI 48202

INTRODUCTION
The Paper Counter and Dispenser will serve in assisting the physically and cognitively handicapped individuals at the Western Wayne Skills Center and surrounding southeastern Michigan schools in special education vocational training classes where disabled students learn employment skills.  Such skills include clerical work that involves paper sorting and bulk mailing. Because it is often difficult and sometimes impossible for physically impaired individuals with motor coordination problems to count, separate, or manipulate single sheets of paper from a stack, a dispenser is necessary to perform such functions.

The electro-mechanical Paper Counter and Dispenser feeds sheets of paper, varying in size, into an output tray where the user may easily collect the sheets of paper, which have been counted to his or her specifications.  More specifically, the device accepts a stack of paper that is loaded into the machine.  A supervisor sets the total number of sheets to be fed; the user activates the paper dispenser by pressing a portable switch pad.  The mechanized rollers grab the paper, pull it onto the device, count the paper, and dispense it into the output tray.  The device continues this cycle until it reaches the set number; then it automatically deactivates.  The output tray is fitted with raised channels, which allow the user to easily remove the paper.

The dispenser must be safe for all possible users.  Some students have a full range of motion and may be able to reach moving components, so the dispenser's drive mechanisms must be enclosed.  Some students have limited motion, so the dispenser must be operable by the push of a button.  Multiple students at different workstations will use the dispenser, so it must fit on a tabletop for easy relocation.
 

SUMMARY OF IMPACT
The device was finished and bench tested in May 2001.  It will be delivered to Western Wayne Skills Center this September for field-testing in a special education classroom.  We anticipate that the device will serve its intended function and allow students with physical and cognitive disabilities to take part in the paper sorting, counting, and mailing tasks from which they are now precluded.

TECHNICAL DESCRIPTION

Low speed, low volume paper handling, sorting, and counting operations are common components in special education office skills classes. While high-speed office automation systems are commercially available, they are too expensive for classroom use. More critically, they are not designed for the low volume, low speed, person-based operations found in the special education setting.  The design challenge is to find a low cost, safe, and reliable system for low volume, low speed, operator-involved paper handling, sorting, counting, and dispensing system.

The client’s major objective is to provide a technological intervention that will allow students with a range of physical and cognitive disabilities to participate in the mailing, sorting, and counting tasks.  Furthermore, the technological intervention should allow the students to work as independently as possible. Based on the client’s specifications, the system should handle single sheets of letter and legal sized paper in various sizes, folded single sheets, envelopes, and, if possible, small multi-page pamphlets and newsletters. In addition, the system must be able to count the items and dispense them in a way that is easy for the students to retrieve.  It must be easy for the students to place the sheets into the system.  The system should be operable by a movable pad switch.

The student design team reviewed patents and studied commercially available systems such as, printers, photocopiers, and fax machines, as well as sorting and counting systems. The essential components of the system included: an ergonomically simple input process/mechanism, a reliable sheet-separating mechanism integral with the paper grabbing and movement mechanism, the ability to electronically count sheets, and an ergonomically sound collection and operator retrieval process/mechanism.

Figure 1 shows the completed device.  There is an input tray that slides out of its holder so that it is easy to place paper, envelopes, or newsletters into the tray.  The tray has movable sides so that different sizes of paper can be accommodated. When the input tray is pushed into place there is a pressure panel in the bottom front of the tray that moves over a spring-loaded roller on the base of the unit.

This spring loaded roller puts pressure on the bottom panel and forces the paper upward toward the drive roller.  This persistent force between the top sheet of paper and the drive roller ensures that the roller will grab the paper and move it forward. As the feed rollers grab a sheet of paper a friction based separation pad works to separate the top sheet from other sheets that may be attached. Next, a second feed roller that rotates faster than the lead feed roller catches the top sheet.  This speed differential is created by the geared belt drive mechanism.  The speed differential causes the top sheet to advance faster than any other sheets.  A slip gear drives the initial feed roller so that when the second faster drive grabs the top sheet and pulls it forward, the increased reverse force on the initial feed roller causes it to slip.  This slippage further enhances the sheet separation process in that sheets not caught by the second roller slow or stop forward movement.

A photoelectric sensor is mounted just beyond the second roller.  As the sheets exit the roller and drop into the output tray, there is a separation that can be sensed and a signal transmitted to an electronic controller unit.  When the controller senses the required number of sheets it stops the feed rollers.  The student can now remove the specified number of pages from the output tray.