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Jam Nut

Stop Bolt

Pivot Pin

Snubber Block

788, 789 Series

Spring Keeper Bolts

Adjusting Nut

Spring Keeper

Spring Regulator

790 Series Counterbalance

Travel Stop 788, 789, 790 Series

Upward

Remove the (4) socket head screws in snubber 
block, then rotate snubber block toward pivot 
pin to allow for more upward travel or away 
from pivot pin for less upward travel.
Replace the (4) screws and tighten.

Adjustment 788, 789 Series

When to adjust torque

NOTE:

 Left hand spring balance shown.

NOTE:

 The worm gear adjustment mechanism provides significant mechanical advantage during adjustment. 

Under high load conditions (790) it is recommended that the loading arm be raised to approximately 45° above horizontal. 
Under low load conditions it is possible to adjust the spring torque without raising/supporting the loading arm.

Torque

For more lifting action increase torque.
For less lifting action decrease torque.

1.  Raise loading arm to highest position and secure.

2.  Hold Adjusting Nut of Spring Regulator [2] with a large wrench.

3.   Loosen lower Bolt of Spring Keeper and remove upper one. 

Using a large screwdriver push Spring Keeper forward. With 
Spring Keeper disengaged turn Spring Regulator Adjusting Nut 
clockwise for more or counter clockwise for less torque. 

4.   With spring tension in desired position press Spring Keeper back 

into position on Spring Regulator. While holding Spring Regulator 
Adjusting Nut, tighten Spring Keeper Bolts [3]. Be sure Lock 
Washers [4] are in place.

5.   Minor adjustment can be achieved by turning the Spring Keeper 

½ position. This is done by removing the 2 Keeper Bolts [3] and 
turning the Spring Keeper end for end, so that the “teeth” of the 
Spring Keeper will be reversed.

Downward

Loosen Jam Nut (located below lever arm) and 
turn stop bolt in for more downward travel or 
out for less downward travel. Then hold bolt 
and tighten jam nut securely.

Summary of Contents for OPW 788 Series

Page 1: ...taining Rings 14 4 Remove the 4 Socket Head Screws 18 and take Snubber Block 26 off 5 Raise loading arm to highest position as vertical as possible 6 Attach front side of Link Arm 17 to mounting ears on loading arm with Pin 16 and 2 Retaining Rings 14 7 Check balancing action by pulling down the arm If adjustment is necessary follow adjustment instructions below 8 Install lock down unit 788 L if u...

Page 2: ...H 30320 RE Pin Torsion Spring SST Index Qty Part Description 17 1 E 20041 D1 Link Arm D1 18 4 H 31278 M Socket Head Screw ZP 31 18 X 1 19 2 H 02507 M Lockwasher CP 5 8 20 2 H 05910 M Screw Hex Cap CST ZP 5 8 11 x 13 4 21 1 E20181 790 Spring Balance Cover RH 22 2 H32321M Spring Cover Latch SouthCo 23 4 H32322M Screw Thread Forming 8 32 24 1 C 00626 M Spring Torsion C 25 1 H 30742 RS Bar Safety 26 1...

Page 3: ... lifting action increase torque For less lifting action decrease torque 1 Raise loading arm to highest position and secure 2 Hold Adjusting Nut of Spring Regulator 2 with a large wrench 3 Loosen lower Bolt of Spring Keeper and remove upper one Using a large screwdriver push Spring Keeper forward With Spring Keeper disengaged turn Spring Regulator Adjusting Nut clockwise for more or counter clockwi...

Page 4: ...pring Keeper 17 Nut 6 Spring Arm 18 Screw 7 Lever 19 Cover NOT SHOWN 8 E ring 20 Spring Compression 8 Pin 21 Snubber Retainer 10 Support Bracket 22 Snubber Plunger 11 Bearing Flange 23 E ring 12 Side Support 24 Pin DANGER Danger Before performing any maintenance always secure the Loading Arm and remove all tension from the counterbalance a torsion spring The Loading Arm counterbalance spring conta...

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