Xerox Phaser 4620 Service Manual page 405

Figure 3 Stapler Components
Staple Limit
Sheets of media are tamped in the Compile Tray, and then positioned for stapling. The number
of sheets is limited to prevent Stapler damage. If the number of sheets per set exceeds the limit
set in NVRAM, the sheets exceeding the limit are ejected to the tray without being stapled. A
single sheet set is also ejected without being stapled. The stapling limit per set is 50 sheets.
Stapler Sensors/Motors
• Low Staple Sensor
A sensor in the Stapler detects near end of staples. The Low Staple Sensor signal goes
High when the quantity of staples remaining in the cartridge is approximately 20 or less.
• Self Priming Sensor
A sensor in the Stapler detects the Staple Cartridge is empty, or a failure in stapling. The
Self Priming Sensor signal goes Low to indicate that the Stapler is ready to staple.
• Staple Home Sensor
A photo-interrupter in the Stapler to detect staple failure. This sensor also functions as a
trigger to stop the staple motor. The Staple Home Sensor signal goes Low while the Sta-
pler Head is at the home position.
• Staple Motor
A DC motor in the Stapler to for stapling. Clockwise rotation of this motor staples, while
counterclockwise rotation opens the Stapler.
Revision - Xerox Internal Use Only
Phaser 4600/4620 Printer Service Manual
Stacker
Stacker Tray
The Stacker Tray adjusts position according to the state of the Stack Full and Limit Sensors.
When media actuates the Stack Full Sensor, the Elevator Motor is activated to move the
Stacker Tray down until the sensor's signal returns to a Low state. If the Limit Sensor is low,
indicating the Stacker Tray is at its limit of travel, a stack full message is displayed on the Con-
trol Panel. If an obstacle blocks the tray from lowering, the tray stops and a warning is reported.
The Stacker No Paper Sensor is switched by an actuator attached to the right-hand Carriage
assembly. In case the Stacker Lower Tray goes above the Stacker No Paper Sensor, the Upper
Limit Sensor is installed directly above the No Paper Sensor as a lift cutoff for abnormal opera-
tion.
Stacker Tray Sensors/Motors
• Stack Full Sensor
Detects the height the Stacker Tray and controls the Elevator Motor. When blocked by the
flag of the left guide, the sensor indicates the lower limit of Stacker Tray travel.
• No Paper Sensor
A photo-interrupter to detect that the tray is at the highest position, and also to detect no
paper. When the actuator enters the sensing area, the emitted light is blocked, switching
the Stacker No Paper Sensor signal to High.
• Elevator Motor
A DC motor to raise or lower the Stacker Lower Tray. Clockwise rotation elevates the tray,
counterclockwise rotation lowers the tray.
Finisher Interlock
The Finisher is equipped with two interlock switches. One is activated when the Staple Car-
tridge Door is opened blocking power to the finisher motors. The other, when the media set
exceeds 50 sheets or a jam occurs.
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Principles of Operation
Finisher