SIGNA MR355 / SIGNA MR360
Service Manual
5856356-3EN Revision 5.0
Basic Service Documentation. Copyright General Electric Company.
Object ID: 00000018WIA30F16E20GYZ
Topic ID: id_13106126 Version: 4.0
Date: Feb 14, 2020 4:05:07 PM

Dock Centering and Dock Hardware Adjustments

Prerequisites

Table 1. Personnel requirements
Required persons	Preliminary requirements	Procedure	Finalization
2	Not Applicable	Not Applicable	Not Applicable

Table 2. Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
Nonferrous Adjustable Wrench	1	-	-	-
Nonferrous Flat-head Screwdriver	1	-	-	-
Socket Wrench	1	-	-	-
Allen Screwdriver	1	-	-	-

Table 3. Consumables
Item	Quantity	Effectivity	Part number	Manufacturer
Loctite® 242	1	-	-	-

Table 4. Safety

DANGER

FATAL ELECTRIC SHOCK HAZARD!

TO PREVENT FATAL ELECTRIC SHOCK, DISCONNECT POWER FROM THE PDU BEFORE YOU PERFORM THE FOLLOWING PROCEDURES.

PERFORM LOCKOUT / TAGOUT (LOTO) PROCEDURE PER GE OSHA LOto REQUIREMENTS LISTED IN THE FIELD SERVICE EHS MANUAL & TRAINING 2000 P/N 2135387-200.

Warning

POSSIBLE PERSONAL INJURY!

THIS PROCEDURE REQUIRES Movement OF FERROUS MATERIAL IN CLOSE PROXIMITY TO THE MAGNET.

TWO FIELD ENGINEERS ARE REQUIRED AT ALL TIMES.

Warning

Personal injury and equipment damage!

Strong Magnetic Field.

When servicing any magnetic equipment, it is critically important that the service engineer consciously plan the path to be taken when moving highly ferrous devices in the magnet environment. the path should be as far from the magnet as practical.

Safety Requirements

The service path must allow for the dock to be moved along the ground a distance equal to that of the distance between the magnet and the foot end of the patient table prior to being lifted vertically

Two (2) MR safety trained personnel must be present at all times when servicing highly ferrous devices in the area of all magnetic fields.

When planning a service path, it is critical that the path be clear and sufficiently wide. Ensure that there are no trip hazards, obstacles, clutter, slippery surfaces or other items even partially restricting the path. If there are portable obstacles in a path, remove them from the area and replace them after the service action is completed. Walk the path prior to beginning service to ensure sufficient space through which to pass for service personnel and the object being serviced.

About this task

The Dock Hardware Adjustment procedures describe how to adjust the Motor On Switch Actuation and a number of Gear Assembly components for noise reduction. Each of these procedures requires removal of the dock as the initial step:

Motor On Switch Actuation Adjustment - The Motor On Actuation Switch in the dock assembly should be adjusted so it is activated when the Table Up foot pedal is pressed approximately 3/4 of its total length of travel. This is factory adjusted; however, it is possible to adjust the position of the Motor On Switch in the field to maintain the proper actuation level.
Gear Assembly Noise Adjustments - The Dock Motor Gear Box has a clutch that prevents backlash on the gears in the gear box. This clutch is not intended to regulate dock motor speed; it prevents gear backlash, which would make the gear assembly noisy. Perform the procedures in Cam Adjustment Procedure, Motor Tube Spring Check, and Clutch Adjustment in the sequence presented to correct excessive gear assembly noise. There are three probable causes of a noisy gear assembly:
- Cam improperly adjusted
- Excessive play on motor tube spring
- Clutch improperly adjusted

The Dock Centering procedure provides the Longitudinal Adjustment (in and out), and the Lateral Adjustment (left to right) to center the dock. For proper Patient Transport docking, the dock assembly must be adjusted to meet two criteria:

Gap between patient transport top and front of magnet enclosure must be 3/4, ±1/4 inch (19.0, ±6.4 mm) to ensure the gap is narrow enough so UP Limit Sensor operates properly, and wide enough so there is no finger pinch hazard when docking the transport.
Dock assembly must be square to the bridge, so axis of cradle travel is the same for both the patient transport and bridge.

Dock Removal

Procedure

DANGER

FATAL ELECTRIC SHOCK HAZARD!

TO PREVENT FATAL ELECTRIC SHOCK, DISCONNECT POWER FROM THE PDU BEFORE YOU PERFORM THE FOLLOWING PROCEDURES.

PERFORM LOCKOUT / TAGOUT (LOTO) PROCEDURE PER GE OSHA LOto REQUIREMENTS LISTED IN THE FIELD SERVICE EHS MANUAL & TRAINING 2000 P/N 2135387-200.

Follow instructions in Section 4.1 of LCC Dock Replacement to remove the dock from the Magnet Room.

Continue to selected procedure:
- For Dock Adjustment:
- For Dock Centering:
  1. Longitudinal Adjustment (In and Out)
  2. Lateral Adjustment (Left to Right)

Motor On Switch Actuation Adjustment

Procedure

Follow instructions in Section 4.1 of LCC Dock Replacement to remove the dock from the Magnet Room.
Remove the four mounting bolts from main dock cover shown below.
Slide the main dock cover forward until Up Limit Switch pushrod just clears the main dock cover holes.

Figure 1. Dock Cover Removal
Remove the front cover (shown below) by removing the two nuts securing front cover to dock.
Loosen the two mounting screws securing the Motor On Switch to the side of the dock assembly.

Figure 2. Motor On Switch Adjustment
Adjust the Motor On Switch position so it is activated (clicks) when the Table Up foot pedal is pressed approximately 3/4 of its total length of travel.
After adjustment is complete, tighten the two mounting screws.
Reinstall the front cover by reattaching the two mounting nuts.
Carefully position main dock cover so the Up Limit Switch pushrod is aligned with the upper hole in the main dock cover.
Replace the main dock cover by securing four mounting bolts shown in Figure 2.

Warning

POSSIBLE PERSONAL INJURY!

THE DOCK CONTAINS FERROUS MATERIALS.

FROM THIS POINT OF THE PROCEDURE FORWARD, DOWNWARD PRESSURE MUST BE CONTINUOUSLY APPLIED TO THE DOCK BY TWO PEOPLE SIMULTANEOUSLY TO PREVENT IT FROM BEING PULLED INTO THE MAGNET BORE.

Follow instructions in Section 4.4 of LCC Dock Replacement to reinstall the dock assembly.

If adjusting the cam, proceed to Cam Adjustment. (There are no Finalization steps required.)

Cam Adjustment

Procedure

Follow instructions in Section 4.1 of LCC Dock Replacement to remove the dock from the Magnet Room.
Remove the four mounting bolts from the main dock cover shown below.
Slide the main dock cover forward until the Up Limit Switch push rod just clears the dock cover holes.

Figure 3. Dock Cover Removal
Check the four set screws on the Motor Cam shown below. If the set screws are loose, apply Loctite 242 to the set screws and tighten them. Allow 15 minutes to harden.

Figure 4. Dock Motor Cam Adjustment
Carefully position the main dock cover so the Up Limit Switch pushrod is aligned with the upper hole in the dock cover (shown in Figure 3).
Replace the main dock cover and secure with the four mounting bolts.

Warning

POSSIBLE PERSONAL INJURY!

THE DOCK CONTAINS FERROUS MATERIALS.

FROM THIS POINT OF THE PROCEDURE FORWARD, DOWNWARD PRESSURE MUST BE CONTINUOUSLY APPLIED by two people simultaneously TO THE DOCK TO PREVENT IT FROM BEING PULLED INTO THE MAGNET BORE.

Follow instructions in Section 4.4 of LCC Dock Replacement to reinstall the dock assembly.

Exercise Table UP pedal to ensure the gear noise was eliminated. If not, remove the dock assembly as described in Dock Removal, and proceed to Motor Tube Spring Check.

Motor Tube Spring Check

Procedure

Warning

POSSIBLE PERSONAL INJURY!

THE DOCK CONTAINS FERROUS MATERIALS.

FROM THIS POINT OF THE PROCEDURE FORWARD, DOWNWARD PRESSURE MUST BE CONTINUOUSLY APPLIED BY TWO PEOPLE SIMULTANEOUSLY TO THE DOCK TO PREVENT IT FROM BEING PULLED INTO THE MAGNET BORE.

Follow instructions in Section 4.1 of LCC Dock Replacement to remove the dock from the Magnet Room.

Remove the four mounting bolts from main dock cover shown below.

Figure 5. Dock Cover Removal
Check the play between the Tube Spring and the Motor Mounting Bracket shown below.

Figure 6. Tube Spring and Motor Bracket
If play is more than 0.025 in. (0.6 mm), replace the tube spring.
Replace the main dock cover on the dock assembly

Warning

POSSIBLE PERSONAL INJURY!

THE DOCK CONTAINS FERROUS MATERIALS.

FROM THIS POINT OF THE PROCEDURE FORWARD, DOWNWARD PRESSURE MUST BE CONTINUOUSLY APPLIED by two people simultaneously TO THE DOCK TO PREVENT IT FROM BEING PULLED INTO THE MAGNET BORE.

Follow instructions in Section 4.4 of LCC Dock Replacement to reinstall the dock assembly.

Exercise the Table Up pedal to ensure gear noise was eliminated. If not, remove the dock assembly as detailed in Dock Removal and proceed to Clutch Adjustment.

Clutch Adjustment

Procedure

Warning

POSSIBLE PERSONAL INJURY!

THE DOCK CONTAINS FERROUS MATERIALS.

FROM THIS POINT OF THE PROCEDURE FORWARD, DOWNWARD PRESSURE MUST BE CONTINUOUSLY APPLIED BY TWO PEOPLE SIMULTANEOUSLY TO THE DOCK SO AS TO PREVENT IT FROM BEING PULLED INTO THE MAGNET BORE.

If the dock is not already removed from the Magnet Room, follow instructions in Section 4.1 of LCC Dock Replacement to remove it.

Remove the four mounting bolts from the main dock cover shown below.

Figure 7. Dock Cover Removal
Loosen the set screw on the Clutch Adjustment Knob shown below.

Figure 8. Dock Motor Clutch Knob
Notice

Do not adjust the clutch more than two clicks at a time. The clutch should not be tightened to the point where it affects the dock motor function.
Adjust the knob two clicks tighter (clockwise), and tighten the set screw.
Replace the main dock cover on the dock assembly.

Warning

POSSIBLE PERSONAL INJURY!

THE DOCK CONTAINS FERROUS MATERIALS.

FROM THIS POINT OF THE PROCEDURE FORWARD, DOWNWARD PRESSURE MUST BE CONTINUOUSLY APPLIED by two people simultaneously TO THE DOCK TO PREVENT IT FROM BEING PULLED INTO THE MAGNET BORE.

Follow instructions in Section 4.4 of LCC Dock Replacement to reinstall the dock assembly.

Exercise the Table Up pedal to ensure gear noise was eliminated. If not, remove dock assembly as detailed in Dock Removaland repeat the adjustment procedures described in Cam Adjustment through Clutch Adjustment.

Longitudinal Adjustment (In and Out)

Procedure

With the Patient Transport docked, measure the distance from the patient transport top to the front end bell as shown below. Dimensions A and B should be 3/4, ±1/4 in. (19.0, ±6.4 mm) and equal to each other so the patient transport top is colinear with the bridge.

Figure 9. Table Docking Measurement for Dock
Follow instructions in Section 4.1 of LCC Dock Replacement to remove the dock from the Magnet Room.
If adjustment is required, add or remove washers until the proper gap is achieved as shown below.

Figure 10. Dock Positioning Adjustment

Warning

POSSIBLE PERSONAL INJURY!

THE DOCK CONTAINS FERROUS MATERIALS.

FROM THIS POINT OF THE PROCEDURE FORWARD, DOWNWARD PRESSURE MUST BE CONTINUOUSLY APPLIED by two people simultaneously TO THE DOCK TO PREVENT IT FROM BEING PULLED INTO THE MAGNET BORE.

Follow instructions in Section 4.4 of LCC Dock Replacement to reinstall the dock assembly.

Lateral Adjustment (Left to Right)

Procedure

Raise the patient table to the maximum height using the Up foot pedal.
Dock the Patient Transport.
Check the alignment of the Patient Transport against the bridge. The guide rail down the length of Patient Transport top should match the guide rail down the length of bridge as shown below.
- Left-to-Right Only: Follow Table Top Height Adjustment.
- Left-to-Right Only: Follow Table Top Height Adjustment.
Figure 11. Aligning Guide Rails

Warning

POSSIBLE PERSONAL INJURY!

THE DOCK CONTAINS FERROUS MATERIALS.

DO NOT remove any mounting screws or nuts; only loosen them.

If dock adjustment is required:

Loosen the screws mounting the dock bracket to the magnet and the cover support brackets to the dock bracket, and loosen the nuts mounting the dock to the dock bracket. (See the illustration below.
Move the dock to a proper position so the guide rails line up. Lift the dock bracket slightly off the ground (approximately 1 mm) and tighten all fasteners.

Figure 12. Dock Positioning Adjustment

What to do next

Finalization

No finalization steps.