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Assembly Directions
93-9501164  REV  B

Page

2 of 6

Mechanism Operation:

When the variable back locking mechanism is operating properly, the following actions will occur:

1.

With the back attitude control button in the forward position (towards the front of the chair) the chair will tilt.

2.

When you do not want the chair to tilt, move the button to the rear and the back will lock in any attitude.  Control
button should always clear outer plastic seat shell and actuation force should not be excessive.

Variable Back Attitude Replacement and Mechanism Adjustment:

Should the chair fail to perform satisfactorily in any of the functions described above check adjustment per step 8.
If adjustment is satisfactory and the variable back locking mechanism is not operating properly, replace according
to steps 1 thru 11.

Package Contents

HOUSING AND

GEAR ASSEMBLY

(2) 5/8” RETAINER RINGS

(2) PIVOT BUSHINGS

OVERCENTER

SPRING

RETAINER

RING

1/4” PIN

PAWL

1/4” RETAINER RING

ADJUSTABLE 

CONTROL ARM

U-JOINT 

ASSEMBLY

U-JOINT PIN

LUBRIPLATE OR

AMOCO GREASE PACK

Summary of Contents for Con-Centrx 451-141

Page 1: ...e Variable Back Locking Mechanism Package Number 25 4540800 These directions apply to the following Con Centrx chair models Managerial chair 451 141 141M 171 171M 147 147M 177 and 177M Operator chair 454 150 150M 180 180M 151 151M 152 152M 181 181M 182 and 182M IMPORTANT Please read these directions completely through prior to starting step 1 A W L O POWER ...

Page 2: ...ays clear outer plastic seat shell and actuation force should not be excessive Variable Back Attitude Replacement and Mechanism Adjustment Should the chair fail to perform satisfactorily in any of the functions described above check adjustment per step 8 If adjustment is satisfactory and the variable back locking mechanism is not operating properly replace according to steps 1 thru 11 Package Cont...

Page 3: ...k shell from upholstered back NOTE Extreme care should be taken with the screwdriver when removing screws to prevent damage to the outer plastic shell 10 SCREWS 1 2 LONG OUTER BACK SHELL 8 SCREWS 1 1 2 LONG 8 SCREW 1 1 8 LONG UPHOLSTERED BACK VARIABLE BACK LOCKING MECHANISM IMPORTANT THIS CIRCLED AREA INDICATES THE LOCATION FOR THE FOLLOWING STEPS 2 3 4 5 and 6 ...

Page 4: ... control arm by hand Save adjustable control arm for the adjustment of new control arm Old removed parts are not to be used ADJUSTABLE CONTROL ARM 3 Remove the retainer ring from the end of the pivot pin by using the flat bladed screwdriver and slide pin out Remove overcenter spring and pawl from lower mounting bracket Old removed parts are not to be used PAWL ADJUSTABLE CONTROL ARM RETAINER RING ...

Page 5: ...d gear assembly clock wise while at he same time lifting up thus removing it from the chair Old removed parts are not to be used 6 Remove retainer ring from the end of u joint pin by using a flat bladed screwdriver Slide pin out and remove u joint assembly RETAINER RINGS PIVOT BUSHING PIVOT BUSHING HOUSING AND GEAR ASSEMBLY HOUSING AND GEAR ASSEMBLY RETAINER RING U JOINT ASSEMBLY U JOINT PIN ...

Page 6: ...parts NEW ADJUSTABLE CONTROL ARM Assembly Directions 93 9501164 REV B Page 6 of 6 EXISTING DIMENSION FOR OLD ADJUSTABLE CONTROL ARM LUBRIPLATE OR AMOCO GREASE U JOINT ASSEMBLY 8 Place the chair upright on the floor Check the chair to verify that all functions are operating properly Invert the chair back onto workbench and reassemble the outer back shell onto upholstered back This step is in revers...

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