Paper Loading Mechanism Epson Stylus Photo RX420 RX425 RX430

Paper Loading Mechanism

Fri, 23 Sep 2011 03:23:18 | Epson Stylus Photo RX420

The Paper loading mechanism consists of the Change Lever in the Pump Unit, the Holder Shaft Unit (including the Clutch mechanism) and the ASF Unit. The Change Lever and the Clutch mechanism play a major role in the Paper loading mechanism as follows.

1. ASF home position detection function

The ASF Unit on this printer does not have the ASF Home Position Sensor. Instead of the ASF Home Position Sensor, the Change Lever and the Clutch mechanism is used to detect the ASF home position.

When the Change Lever is set on the Clutch mechanism with the counterclockwise rotation of the PF Motor pinion gear, the ASF home position is detected by this lever for the paper loading operation. In this time, the printer cannot load a paper from ASF Unit because the drive of the PF Motor is not transmitted to the LD Roller Shaft.

2. Paper loading function

When the Change Lever is released from the Clutch mechanism with the clockwise rotation of the PF Motor pinion gear, the ASF home position detection function is changed over to the paper loading function. Therefore, the printer can load a paper from ASF Unit because the drive of the PF Motor is transmitted to LD Roller Shaft.

During paper loading, paper is transported from the ASF Unit into the printer by the rotation of the 2 cams of the LD Roller.

When 1 page paper is loaded, the cams mentioned above prepare the Hopper and Paper Back Lever for the next paper loading operation, and the remaining paper is returned to the standby position.

Figure 2-7 (p.62) and Figure 2-8 (p.63) show you the ASF paper loading sequence and the operation of each mechanism.

When the PF Motor pinion gear rotates CCW direction (right side view), the Change Lever pushes down the Clutch lever as right figure and the Clutch lock tooth is disengaged from the Clutch Gear. As the result, the LD Roller Shaft dose not rotate at all because the drive of the PF Motor is not transmitted. In this time, the Hopper is also pushed down by the two cams on the LD Roller Shaft, and the Paper Back Lever is set to avoid that papers are slipped down from the paper set position.

This position is the ASF home position.

Step 1 (ASF Home position)

Hopper & Paper Back Lever condition

Hopper release cam

LD Roller Shaft

LD Roller

Paper Back Lever Torsion Spring 6.45

Step 1 (ASF Home position)

Hopper & Paper Back Lever condition

Hopper release cam

LD Roller Shaft

LD Roller

Paper Back Lever Torsion Spring 6.45

Compression Spring 5.58

ASF Frame

Compression Spring 5.58

ASF Frame

Gear rotation direction (Right side view)

Spur Gear 13.5 (PF Roller)

Gear rotation direction (Right side view)

Spur Gear 13.5 (PF Roller)

: <PF Motor drive transmission path for ASF home position setting>

PF Motor pinion gear (CCW) ^ Spur Gear 30.8 (CW) ^ Spur Gear 32.4 (PF Roller) (CCW) ^ Spur Gear 13.5 (PF Roller) (CCW) ^ Combination Gear 21.24 (CW) ^ Spur Gear 27.2 (CCW) ^ Spur Gear 16 (CW) ^ Change Lever (CW) ^ Combination Gear 27.2, 19.2 (CCW) ^ Spur Gear 36.8 (CW) * Above transmission pass = seen from the right side of the printer

Step 2

Hopper & Paper Back Lever condition

: Gear rotation direction (Right side view)

PF Motor pinion gear (CW) ^ Spur Gear 30.8 (CCW) ^ Spur Gear 32.4 (PF Roller) (CW) ^ Spur Gear 13.5 (PF Roller) (CW) ^ Combination Gear 21.24 (CCW) ^ Spur Gear 27.2 (CW) ^ Spur Gear 16 (CCW) ^ Change Lever (CCW) ^ Combination Gear 27.2, 19.2 (CW) ^ Spur Gear 36.8 (CCW) * Above transmission pass = seen from the right side of the printer

Figure 2-7. ASF Paper Loading Sequence (Step 1, 2)

When a paper is loaded from the ASF Unit, the Change Lever moves to the front side of the printer with the CW rotation (right side view) of the PF Motor pinion gear and releases the Clutch lever. As the result, the Clutch turns back to the engagement position by the tension force of the Extension Spring 0.143. And, the Clutch gear is engaged with the Clutch lock tooth to transmit the drive of the PF Motor as left figure. In this time, the Change Lever is locked instantaneously by the protrusion on the backside. of the Carriage Unit to change over from the ASF home position detection function to the paper loading function surely.

The PF Motor pinion gear rotates CCW direction (right side view), and the drive of the PF Motor is transmitted to the LD Roller Shaft through the Clutch lock tooth and the Clutch gear. After the LD Roller pushes down the Paper Back Lever into the ASF Frame, the Hopper is released by the tension force of the Compression Spring 5.58. And, a paper is picked up with the frictional force between the LD Roller and the Pad Hopper.

Step 3

Hopper & Paper Back Lever condition

Hopper release cam

Hopper & Paper Back Lever condition

Hopper release cam

: Compression Spring 5.58

Gear rotation direction (Right side view)

: Hopper release cam

LD Roller Shaft

LD Roller Shaft

Step 4

Hopper & Paper Back Lever condition

Paper Back Lever

Hopper & Paper Back Lever condition

Paper Back Lever

: ASF Frame

: Gear rotation direction (Right side view)

While the LD Roller rotates CCW direction (right side view) continuously, the top of a paper is loaded to the PF Roller. In this rotation, the Hopper returns to the open position and the Paper Back Lever is pushed up by the cam of the LD Roller. In this time, this lever returns papers to the stand-by position in ASF Unit for next paper loading operation. Then, when the rolling LD Roller & the Clutch come at the above "Step 1" position, the Clutch lever is locked with the Change Lever again. In this time, the drive of the PF Motor is interrupted and the drive is transmitted only to the PF Roller side for the paper feeding sequence.

Figure 2-8. ASF Paper Loading Sequence (Step 3, 4)

Printer Self Repair

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