Norton Door
Controls
Surface Mounted Door Closers/Concealed Door
Closers
Norton Door controls can be surface-mounted or concealed in
the door or frame. Each type has its advantages and disadvantages.
Surface-Mounted Closers
This type of door control is easiest to install, with three
or four drilled and/or tapped holes for the body, and two or four holes for the arm
bracket. They require a minimum amount of preparation of the door and frame. The
surface-mounted closer is also more accessible to the occasional adjustment that may be
necessary with changes in usage or environmental conditions. Although surface-mounted
closers, by definition, are never truly concealed, most Norton closers can be ordered with
covers in a variety of painted, plated or wood veneer finishes to soften the closer's
affect on the building design.
Concealed Closers
On the occasions where the architect's design calls for a
door closer that is not visually obvious, there are two types of "concealed"
closers; each varying in the degree to which the total installation is concealed. All
require more door and/or frame preparation than a similar surface-mounted closer.
Overhead Concealed Closers are
normally mortised into the transom of the frame above the door. A slide track is normally
mortised into the top rail of the door. All elements - closer, arm and slide track, are
totally concealed when the door is closed. Norton Overhead Concealed closers provide sweep
and latch speed adjustments, backcheck cushioning and shock absorption. The Series 7900
closers also provide a 50% power adjustment feature. They are available with or without
Hold-Open feature.
Concealed-In-a Door-Closers are
concealed in the top rail of the door. There are several arms available: a sliding arm
that is completely concealed when the door is closed; an exposed parallel arm and an
exposed regular arm. The Norton Concealed In-a-Door Closer is the Series 900, a control
which provides sweep and latch speed adjustments and backcheck cushioning. Hold-open arms
are available.
Regular Arm, Top Jamb and Parallel Arm
There are three basic methods of mounting surface door
closers to the door and frame. The method the architect chooses is influenced by some
combination of these five factors:
Closer position, relative to the locations of door, frame
and hinges;
Space limitations on the top rail of the door;
Space limitations on the frame face above the door;
Appearance;
and, (especially in schools) Accessibility of the closer
arm.
The three basic mounting methods which follow are
illustrated with a double lever arm. Similar applications, using a single lever arm and a
slide track in place of the double lever arm, are available with the Norton Series 7700
and Series 7500 Door Closers.
Regular Arm
The closer body is mounted on the top rail of the door on
the hinge side of the door. The forearm is mounted to the frame face by means of a
mounting shoe. The closer body requires less space on the door's top rail than a parallel
arm installation, but more space than a top jamb installation. (The top jamb installation
requires space for the arm fastening only.) The arm projects from the door at
approximately a right angle. Finally, the geometry of the assembly makes a regular arm
closer somewhat more power-efficient than a parallel arm closer. |
