Page 15 - Herrajes Patricios - Catalogo LCN

General
Today practically every door in modern commercial, industrial, and institutional buildings is information
opened by the person passing through and closed by a mechanical door closer which keeps the
door under control at all times. The power to close the door is generated by the springs inside
the closer. Regulated hydraulic circuits control the speed of the doors closing swing. Ideal door
“conduct” is illustrated and described in the diagram below. It can be achieved by equipping each Proper door control
door with the appropriate LCN door closer.

Perfect door operation… The aim of mechanical control.

This diagram shows the main part or stages in correct door operation,
whether under manual or mechanical control or a combination of the
two.
(1) On the opening swing, the door closers function is to let
the door open easily, except at the end of the swing
where backcheck is applied.

(2) Backcheck is a feature that cushions the opening swing to prevent
the door from slamming into the stop. Special closers designed for
potentially abusive applications begin the backcheck function much
earlier (2A) such as LCN’s advanced variable backcheck (AVB).
(3) Through the long closing arc, a uniform, reasonable (main) speed
should be maintained.
(4) The latching arc allows the door to close quietly and firmly.

Opening the door builds up the power, which later closes the door.
As a controlled door is opened, the spring of the closer is compressed which builds up the power to close the door. Normally, more opening
force would be required as spring compression increases. However, as an LCN closer changes it’s arm geometry while the door opens, it
increases the door leverage. This offsets the spring compression, resulting in greater ease in opening the door.

In opening, more leverage for the person.
The changing arm geometry gives increased leverage over the door to overcome the growing power of the spring allowing one to pass
through the door easily.

In closing, more leverage for the closer.
When the person releases the door and the closer takes over, spring power is applied through the arm system to close the door. Because
the spring has been compressed, its power is very high. As the door closes the spring expands, providing the power to
close the door.

Special closers for reduced opening force.
The 1990 Americans with Disabilities Act (ADA) and ANSI Standard A117.1 describe maximum opening force limitations for certain non-fire
rated doors. The last page of each closer section in the catalog includes a section titled REDUCED OPENING FORCE CLOSERS. This section
lists closers in that specific series that will comply with a maximum opening force based on the width of the door.
Any manual door closer, including those certified by BHMA to conform to ANSI Standard A156.4, that is selected, installed, and adjusted
based on ADA or other reduced opening force requirements may not provide sufficient power to reliably close and latch the door.
Refer to AUTOMATIC OPERATORS section for information on electric, pneumatic and electromechanical systems that meet
reduced opening force requirements without affecting closer power.

LCN Door Control Catalog A15
phone: 877-671-7011 n fax: 800-248-1460 n www.allegion.com/us n 009426 rev. 11/16