Oce 3121 Technical & Service Manual page 490

Releasing the ramp
When the cassette is withdrawn, it releases the ramp. One claw raises the ramp,
another claw holds the ramp up. When the machine is at stand-by, the ramp is
held by the retaining claw. When the cassette is opened, the retaining claw is
released, and the ramp drops.
If the power supply fails while the ramp is being raised, the claw for
Warning:
raising the ramp holds the ramp up. In such cases, ensure that the machine is
switched OFF, then ON. This makes sure that the cassette is released in the
proper manner.
Operation of the pick-up from the cassette
a) Pick-Up Operation
The pick-up roller is driven by the motor M4, via a gear system.
1
The motor M4 is controlled by the cassette pick-up PBA. When the paper feed
2
is from the upper cassette, motor M4 runs clockwise. Motor M4 runs coun-
ter-clockwise when the paper is fed from the lower cassette
Sensor for the pick-up roller (S5)
3
When the cassette is closed, the pick-up roller is lowered and the ramp is raised
to bring the paper into position.
b) Drive Control
When M4 rotates clockwise, gear 1 is raised to drive the pick-up roller for the
upper cassette.
When M4 rotates counter-clockwise, gear 1 is lowered to drive the pick-up
roller for the lower cassette.
motor for cas-
sette pick-up
gear 1
ed.1
gear 1
gear 1 and clockwise rotation
gear 1 and counter-clockwise
rotation
12 Paper trays 509