NORTON 7500 Series
Unitrol Door Closer
- Non-handed
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Rack-and-pinion design
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Cast aluminum body
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2⅛" projection
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1½" diameter piston
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⅝" diameter pinion journals
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Standard, separate and independent, latch, sweep and backcheck intensity valves
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Backcheck positioning valve
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Molded plastic cover
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All standard arm applications allow doors to swing 180 degrees, conditions permitting
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Unitrol arm (parrallel arm only), please specify door width
- Sex nuts included
Closer
bodies are constructed of a special aluminum alloy, carefully selected
to accommodate interactive steel components and operating conditions.
Rack
& pinion operation provides a smooth constant control of the door
through its full opening and closing cycle. 180° door swing can be
achieved when door, frame, hardware and arm function do not interfere.
Unitrol arms combine the features of a double lever arm overhead door stop/holder with the backcheck feature of the door closer to reduce door stopping shock loads to a minimum. The Unitrol uses a compression spring buffer at the soffit plate/arm shoe that will absorb 30 lbf. of force, 5° prior to the door’s dead stop. Coupled with the door closer’s backcheck feature, this arm provides the most controlled stop available with a surface door closer.
Adjustable Delayed Action Closing (Optional)
An optional hydraulic feature, available in lieu of backcheck, adds a third speed range to the closing cycle. This feature becomes effective when the door is opened and released at any point beyond 70°. The amount of time delay depends upon the combination of the angle of door release and valve adjustment. The valve can be adjusted with a 1/8" (3mm) hex key from no delay time up to maximum delay times of:
Door Opened
and Released at
|
Approximate Time
of Delay Cycle
|
180°
|
4-5 minutes
|
120°
|
2-3 minutes
|
90°
|
25-30 seconds
|
|
