Discovery MR750 3.0T System Service Methods
5690009-2EN Revision 4
Object ID: 00000018WIA3005BE20GYZ
Topic ID: id_13107252 Version: 2.6
Date: Jan 26, 2022 10:55:01 AM

Replacing the cradle guide rail

Prerequisites


Personnel requirements
Required persons	Preliminary requirements	Procedure	Finalization
1	-	30 minutes	-


Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
Nonmagnetic Tool Kit	1	-	5112581	-


Replacement parts
Item	Quantity	Effectivity	Part number	Manufacturer
LH Guide Rail	1	-	-	-
RH Guide Rail	1	-	-	-
Guide Rail Shim	1 to 3	-	-	-

Topic ID: id_SL4463463-1094857

Overview

About this task

This procedure describes how to replace the cradle guide rail. The cradle is locked in the home position with a latch on the patient table bridge. The latch engages a notch on the cradle guide rail at the rear of the table. The latch on the cradle should engage this notch just enough (without extra force) so when the cradle is pushed to the home position, it tightly engages the notch to prevent the table top from moving when the patient table is undocked. In certain situations, it may be necessary to add up to a maximum of 3 shims to achieve a minimum distance of 369 mm.

Figure 1. Shim placement behind guide rail on patient cradle

Topic ID: id_SL2905731-1094857

Removing the guide rail

Procedure

Note:
Two guide rails (LH and RH) are used to guide the cradle when moving the cradle forward and backward on the table top. Fives screws secure each guide rail to the table top. Each screw mounts through the guide rail and table top to the nut bar. The nut bar is NOT secured to the table top.

To prevent the nut bar from dropping into the table top, always have two screws mounted. Carefully follow each step in this procedure to make sure the nut bar does not drop into the table top during removal or installation. If nut bar drops into table top, the bottom panel of the table top must be removed to retrieve the nut bar.

See the illustration below. To obtain access to the guide rail, move the cradle back (into the magnet).

Figure 2. Moving cradle back

Note:
Two screws in the narrow part of the guide rail should remain installed.
Using a 7/64 inch Allen wrench, loosen each of the three screws (as shown below), and remove them from the wide part of the guide rail.

Figure 3. Removing screw from guide rail

Note:
The nut bar is not secured to the table top. Always keep at least two screws mounted into the nut bar. If nut bar drops into the table top, the bottom panel of the table top must be removed to retrieve the nut bar.
Lift up the guide rail and install the screw (approximately 3 or 4 turns) into the first screw hole of the nut bar as shown.

Figure 4. Screw installed in first hole of nut bar
Remove the fourth screw (shown below) from the narrow part of the guide rail.

Figure 5. Location of fourth screw
Loosen the fifth screw until approximately 1/4 inch of thread is exposed.
Note:
The nut bar is not secured to the table top. Always keep at least two screws mounted into the nut bar. If nut bar drops into table top, the bottom panel of the table top must be removed to retrieve the nut bar.

Lift up the guide rail and install the screw (approximately 3 or 4 turns) into the fourth screw hole of the nut bar. (See Figure 6.)

Figure 6. Location of fourth hole of nut bar
Remove the fifth screw from the guide rail, and remove the guide rail from the table top.

Note:
The nut bar will tilt down with the two screws installed (shown below).

Figure 7. Nut bar with two screws installed
If the other guide rail requires replacement, repeat Step 2 through Step 7.

Topic ID: id_SL2905740-1094857

Installing the guide rail

About this task

Two guide rails (LH and RH) are used to guide the cradle when moving the cradle forward and backward on the table top. Fives screws secure each guide rail to the table top. Each screw mounts through the guide rail and table top to the nut bar. The nut bar is not secured to the table top. To prevent the nut bar from dropping into the table top, always have two screws mounted. Carefully follow each step in this procedure to make sure the nut bar does not drop into the table top during removal or installation. If nut bar drops into the table top, the bottom panel of the table top must be removed to retrieve the nut bar.

Procedure

Install the screw with guide rail (narrow end) into fifth hole of the nut bar. Do not tighten the screw at this time.

If shim(s) need to be installed, install them with the guide rail now. Install the shim(s) on the left rear side of the cradle, between the table top and the guide rail. (See Figure 1.)
Remove the screw from fourth hole of the nut bar as shown below.

Figure 8. Removing holding screw
Aligning the fourth of the guide rail with the fourth of the nut bar, install the screw through the guide rail and into the nut bar. Do not tighten the screw at this time.

Figure 9. Installing screw in fourth hold of nut bar
Install a screw through the third hole of the guide rail (wide end) and into the nut bar. Do not tighten the screw at this time.
Install a screw through the second hole of the guide rail (wide end) and into the nut bar. Do not tighten the screw at this time.
Remove the screw from the first hole of the nut bar.
Install a screw through the first hole of the guide rail (wide end) and into the nut bar.
Using a 7/64 inch Allen wrench, tighten the five screws shown below.

Note:
To apply the proper torque to these screws, insert the long end of the Allen wrench into the head of the screw and tighten only using your fingers. Reverse the Allen wrench (short end into the head of the screw) and tighten 1/2 turn using your fingers.

Figure 10. Tightening screws to secure guide rail
If the other guide rail requires replacement, repeat Step 1 through Step 8.
Adjust the cradle guide rails referring to Cradle Guide Rail Latch Adjustment.

Topic ID: id_14943768

Finalization

No finalization steps.