Xerox Phaser 8860, Service Manual

Page: 309 / 316

09/2007
8-17 Phaser 8860/8860MFP Service Manual
Image Output Terminal
Theory of Operation Initial Issue
Figure 14 Printhead Tilt Drive
In the print position (0 degrees), the Printhead is forward and resting against the right and left
head-to-drum buttons. The head-to-drum buttons define the space between the jet stack and
the drum. When the Process Drive is activated, it drives the Drum Maintenance Camshaft to
engage the tilt gear train. The tilt cam tilts the Printhead into the print position. The cam is com-
bined with a missing tooth gear that allows the cam to be inactive in the print position, freeing
the Process Drive to perform other system operations.
The cam has a latching mechanism to unlatch and latch the Head Tilt Gear to engage the
Printhead tilt drive train. The cam’s latching mechanism also holds the gear in place. A leaf
spring applies constant pressure to engage the gear when the latching mechanism is released.
The arm of the latching mechanism is inside the frame; the rest is visible, outside the frame.
Arrows located on the latching mechanism and on the frame indicate when the Printhead is in
print position. When the arrows on the latching mechanism and frame align, the Printhead is in
the print position and the tilt gear disengages from the Process Drive. The Head Tilt Solenoid is
actuated and deactuated when the Head Tilt Gear rotates to the respective engaged and dis-
engaged positions.
The latching mechanism is actuated by a small movement of the wiper coupled with the Head
Tilt Solenoid. The action of the solenoid ensures that the head-tilt gear engages the tilt drive
gear. Through a follower gear, the compound gear drives the tilt cam gear clockwise. A cam fol-
lower, mounted on the lower end of the tilt arm, follows the rotating tilt cam gear and tilts the
Printhead. After one revolution of the tilt gear, the latching mechanism is pulled back into posi-
tion by the Head Tilt Solenoid.
As viewed from the left side of the system, when the arrows do not align, the tilt gear is
engaged.
Figure 15 Printhead Tilt Detail
To accommodate Printhead maintenance, the Printhead can be tilted back away from the
drum. This creates room for the Wiper to be moved into position in front of the Printhead face-
plate. The Process Drive drives the gears to the tilt compound gear train. The drum mainte-
nance camshaft drives the gear train to tilt the Printhead.
Drum Assembly
The Drum Assembly and transfix system form the key portion of the system where imaging
takes place. The Drum Assembly and transfix system are separate, but interrelated. This sec-
tion discusses the Drum Assembly. The next section goes into more detail on the transfix sys-
tem.