• Object ID: 00000018WIA30C20130GYZ
  • Topic ID: id_12373798 Version: 1.9
  • Date: Oct 7, 2020 10:43:15 AM

Patient Table Up Limit Replacements

Prerequisites

Table 1. Personnel requirements
Required personsPreliminary requirementsProcedureFinalization
1Not Applicable30-120 minutes15-30 minutes
Table 2. Tools and test equipment
ItemQuantityEffectivityPart numberManufacturer
5/16 hex bit (3/8 drive)1---
Non-ferrous Tool Kit1-

5112581

-
Torque Wrench, 8-50 N m Adjustable, non-magnetic1-

5534134 or 5534134-2

-
Table 3. Consumables
ItemQuantityEffectivityPart numberManufacturer
Loctite 242As needed-

See FRU Manual

-
Table 4. Replacement parts
ItemQuantityEffectivityPart numberManufacturer
Up Sensor Cable1-

See FRU Manual

-
Up Sensor Cable Tubing1-

See FRU Manual

-
Up Sensor Top Bracket1-

See FRU Manual

-
Up Sensor Cable1Curved table

See FRU Manual

-
Up Sensor Cable Tubing1Curved table

See FRU Manual

-
Up Sensor Top Bracket1Curved table

See FRU Manual

-
Up Limit Switch Mounting Bracket1Flat table

See FRU Manual

-
Up Limit Switch Adjuster Block1Flat table

See FRU Manual

-
Up Limit Switch Link1Flat table

See FRU Manual

-
Backing Plate with Brass Anchor1-

See FRU Manual

-

About this task

Overview

The patient table up limit switch components are used to set the hydraulic cylinder upper limit. This procedure explains how to replace the patient table up limit switch components.

There are two possible configurations for the table up limit – cable or hook (switch). Follow the instructions for the type of table you are servicing.

The up limit switch mounting bracket for an electrical table requires two persons and the timing varies depending on whether the cradle is removed or not.

See each procedure for specific timing and number of required persons.

Up Sensor Cable and Tubing Replacement (Curved Table Only)

About this task

Required Persons: 1. Procedure Timing: 30 minutes.

Procedure

  1. Undock the patient table and remove it from the magnet room.
  2. Remove the right upper bellows and right lower base side cover, and the front base cover. See Patient Table Upper Bellows and Lower Base Side Cover Removal.
  3. Raise the table to its maximum height.
  4. Lower the table lock safety bar.
    Figure 1. Table Lock Safety Bar
  5. Lower the table and verify that all of the table top's weight is resting on the safety bar.
  6. Remove the hair pin and retaining pin securing the bottom end of the cable to the bell crank.
    Figure 2. Pin and Hair Pin
  7. If you are only replacing the up sensor cable tubing, follow these steps:
    1. Slide the old tubing off and slide the new tubing on.
    2. Fasten the end of the cable to the bell crank, and secure the retaining pin with the hair pin. (See Figure 2)
    3. Proceed to Step 16.
  8. Remove the clamp securing the cable to the up sensor top bracket.
    Figure 3. Table Up Limit Cable Replacement
  9. Remove the retaining ring and washer securing the end of the cable to the up limit pin on the bracket.
  10. Install the new up sensor cable and attach it to the up limit pin.
  11. Fasten the other end of the cable to the bell crank and secure the retaining pin with the hair pin. (See Figure 2)
  12. Attach the clamp securing the cable to the bracket.
  13. Adjust the table up limit cable length to provide enough slack so that when the cylinder is fully raised in the next step, the cable is not stretched and damaged.
  14. Fully raise the cylinder.
  15. Adjust the table up limit cable so that the plunger can move 1 to 2 mm when the hydraulic cylinder is fully extended.

    If the cable is too loose, the plunger will not engage the dock switch fully and the system will not recognize that the table is fully up.

    If the cable is too tight, the cable may break.

    Figure 4. Table Dock Push Button
  16. If there are no additional replacements, proceed to Finalization. Otherwise, continue with the appropriate section below.

Up Sensor Top Bracket Replacement (Curved Table Only)

About this task

Required Persons: 2. Procedure Timing: 90 minutes.

Procedure

  1. Undock the patient table and remove it from the magnet room.
  2. Remove the right upper bellows and right lower base side cover, and the front base cover. See Patient Table Upper Bellows and Lower Base Side Cover Removal.
  3. Raise the table to its maximum height.
  4. Lower the table lock safety bar.
    Figure 5. Table Lock Safety Bar
  5. Lower the table and verify that all of the table top's weight is resting on the safety bar.
  6. Release the cradle and manually slide the cradle forward and either:

    • Have another person hold the cradle end up so you have access to the table top height adjustment screw.

      or

    • Remove the cradle completely.

    See Removing Cradle Assembly

  7. Use a flat head screwdriver to remove the cover plug from the table top height adjustment screw.
  8. Use needle-nose pliers to remove the e-clip from the end of the table top height adjustment screw.
    Note:

    Place a piece of tape over part of the e-clip before removing it so that the e-clip does not become lost during removal. Remove the tape after removing the e-clip.

  9. If the cradle was not removed, slide the cradle back onto the table.
  10. While moving the table down rod to the rear of the table, pull down on the hydraulic shaft. Stop when the hydraulic shaft is low enough to access the top of the up sensor top bracket.
    Figure 6. Hydraulic Shaft
  11. Remove the two screws (at the top of the hydraulic cylinder) attaching the up sensor top bracket to the hydraulic cylinder. Replace the up sensor top bracket.
    Note:

    The top can be rotated, which also changes the table height. Make sure to return the top back to its original position.

  12. Carefully raise the table. The hydraulic cylinder must fit through the hole in the table. Check that the hydraulic cylinder is completely within the hole and that the table height adjustment is accessible.
  13. If the cradle is still attached to the table, release the cradle, manually slide the cradle forward, and have another person hold the end of the cradle so you have access to the table top height adjustment screw.
  14. Re-attach the e-clip and cover plug.
  15. If the cradle was not removed, slide the cradle back onto the table. Otherwise, reinstall the cradle.
  16. Fully raise the cylinder.
  17. Adjust the table up limit cable so that the plunger can move 1 to 2 mm when the hydraulic cylinder is fully extended. See Figure 4.

    If the cable is too loose, the plunger will not engage the dock switch fully and the system will not recognize that the table is fully up.

    If the cable is too tight, the cable may break.

  18. If there are no additional replacements, proceed to Finalization. Otherwise, continue with the appropriate section below.

Up Limit Switch Link Replacement (Flat Table Only)

About this task

Required Persons: 1. Procedure Timing: 30 minutes.

Procedure

  1. Undock the patient table and remove it from the magnet room.
  2. Remove the right upper bellows and right lower base side cover, and the front base cover. See Patient Table Upper Bellows and Lower Base Side Cover Removal.
  3. Raise the table to its maximum height.
  4. Lower the table lock safety bar.
    Figure 7. Table Lock Safety Bar
  5. Lower the table and verify that all of the table top's weight is resting on the safety bar.
  6. Remove the outer hair pin holding the link to the bell crank.
    Figure 8. Hair Pins - Link to Bell Crank
  7. Slide the link out and replace with the replacement link.
  8. Fasten the link to the bell crank using the two hair pins.
  9. If there are no additional replacements, proceed to Finalization. Otherwise, continue with the appropriate section below.

Up Limit Switch Adjuster Block Replacement (Flat Tables Only)

About this task

Required Persons: 1. Procedure Timing: 30 minutes.

Procedure

  1. Remove the up limit switch link. See Up Limit Switch Link Replacement (Flat Table Only).
  2. Remove the left upper bellows and left lower base side cover. See Patient Table Upper Bellows and Lower Base Side Cover Removal.
  3. Confirm that the table top’s weight is resting on the safety bar.
  4. Mark the current location of the adjuster block on the up limit switch mounting bracket.
  5. Remove the two screws holding the adjuster block to the mounting bracket.
    Figure 9. Screws Holding Adjuster Block
  6. Install the new adjuster block to the mounting bracket using the two screws.
  7. Reinstall the up limit switch link.
  8. If there are no additional replacements, proceed to Finalization. Otherwise, continue with the appropriate section below.

Up Limit Switch Mounting Bracket Replacement

About this task

Required Persons: 2. Procedure Timing: 120 minutes.

Procedure

  1. Remove the up limit switch link. See Up Limit Switch Link Replacement (Flat Table Only).
  2. Mark the current location of the adjuster block on the mounting bracket, and then remove the adjuster block. See Up Limit Switch Adjuster Block Replacement (Flat Tables Only)
  3. Release the cradle and manually slide the cradle forward and either:

    • Have another person hold the cradle end up so you have access to the table top height adjustment screw.

      or

    • Remove the cradle completely.

    See Removing Cradle Assembly.

  4. Use a flat head screwdriver to remove the cover plug from the table top height adjustment screw.
  5. Use needle-nose pliers to remove the e-clip from the end of the table top height adjustment screw.
    Note:

    Place a piece of tape over part of the e-clip before removing so that the e-clip does not become lost during removal. Remove tape after removing the e-clip.

  6. If the cradle was not removed, slide the cradle back onto the table.
  7. Confirm that the table top’s weight is resting on the safety bar.
  8. While moving the table down rod to the rear of the table, pull down on the hydraulic shaft. Stop when the hydraulic shaft is low enough to access the top of the up limit switch mounting bracket.
    Figure 10. Hydraulic Shaft
  9. Remove the two screws (at the top of the hydraulic cylinder) attaching the up limit switch mounting bracket to the hydraulic cylinder.
    Note:

    The top can be rotated, which also changes the table height. Make sure to return the top back to its original position.

  10. Measure where the adjuster block was located and make a mark on the new mounting bracket at the same location. (This assumes that the hydraulic cylinder is not turned when removing the bracket.)
  11. Install the new mounting bracket.
  12. Carefully raise the table. The hydraulic cylinder must fit through the hole in the table. Check that the hydraulic cylinder is completely within the hole and that the table height adjustment is accessible.
  13. If the cradle is still attached to the table, release the cradle, manually slide the cradle forward, and have another person hold the end of the cradle so you have access to the table top height adjustment screw.
  14. Re-attach the e-clip and cover plug.
  15. If the cradle was not removed, slide the cradle back onto the table. Otherwise, reinstall the cradle.
  16. Lower the table onto the safety block.
  17. Install the up limit switch adjuster block.
  18. Install the up limit switch link.
  19. Fully raise the cylinder.
  20. Adjust the adjuster block so that the plunger can move 1 to 2 mm when the hydraulic cylinder is fully extended.

    If the adjuster block is too low, the plunger will not engage the dock switch fully and the system will not recognize that the table is fully up.

    If the adjuster block is too high, the mechanical parts may bend or break.

Up Limit Link Mechanism Anchor Replacement (Flat Table Only)

About this task

Required Persons: 1. Procedure Timing: 30 minutes.

Procedure

  1. Undock the patient table and remove it from the magnet room.
  2. Remove the right upper bellows and right lower base side cover, and the front base cover. See Patient Table Upper Bellows and Lower Base Side Cover Removal.
  3. Raise the table to its maximum height.
  4. Lower the table lock safety bar.
    Figure 11. Table Lock Safety Bar
  5. Lower the table and verify that all of the table top's weight is resting on the safety bar.
  6. Remove e-clip and washer from table down rod. Slide table down rod from patient table.
    Figure 12. E-clip and Washer
    ITEM DESCRIPTION
    1Washer
    2E-clip
    3Table Down Rod
  7. Remove hair pin from bell crank. Remove pin to remove cable or hook.
    Figure 13. Backing Plate
    ITEM DESCRIPTION
    1Screws with lockwashers
    2Table down rod
    3Down bracket
    4Brass anchor
    5Hair pin
  8. Remove hair pin and pin from brass anchor.
  9. Using 5/16 hex bit, remove screws and lockwashers from backing plate.
  10. Apply Loctite 242 to screws.
  11. Install new backing plate using existing lockwashers and screws. Torque screws to 38 Nm (28 ft-lbs).
  12. Install bell crank to brass anchor, and secure the retaining pin with the hair pin.
  13. Install cable or link to bell crank.
  14. Slide install table down rod into down bracket.
  15. Install washer and e-clip to table down rod.
  16. If there are no additional replacements, proceed to Finalization.

Finalization

Procedure

  1. Verify proper operation of the table.
    1. Raise the table lock safety bar.
    2. Dock the table.
    3. Verify proper up/down table motion.
    4. When the table is in a fully raised position, verify that the cradle and LPCA can be advanced normally into the bore.
    5. Verify that raising the table to its full height results in the LPCA automatically driving out to engage the cradle.
    6. Verify that lowering the table results in automatic retraction of the LPCA into the bridge.
    7. Verify normal cradle and LPCA motion from the home position to end of travel on the bridge using enclosure In Fast and Out Fast buttons at the operator console.
  2. Replace the upper bellows and lower base covers, and the front base cover.