Sliding door operator
From Wikipedia, the free encyclopedia
A sliding door operator (or sliding door opener or automatic sliding door operator) is a device that operates a sliding door for pedestrian use. It opens the door automatically, waits, then closes it.
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[edit] Uses
Sliding door operators are typically used on the outside doors of large retail businesses. (smaller retail businesses prefer swing door operators.) They are also used in elevators (lifts)
[edit] Triggering
A door operator may be triggered in various ways:
- Approach Sensor (such as a radar sensor) - the door opens when a user approaches it.
- Pushbutton - the door opens when a user presses a button.
- Access control - the door opens when the an Access Control System determines the user is authorized to go through.
- Automatically (in the case of elevators)
A trigger from any of the above requests that the door be opened (or reopened if it was closing).
[edit] Safety sensors
A sliding door operator reopens the door it it closes into an obstacle. However, most operators use sensors to prevent the door from ever coming into contact with a user in the first place.
The simplest sensor is a light beam across the opening. An obstacle in the path of the closing door breaks the beam, indicating its presence.
Also, infrared safety sensors are normally used.
- Header mounted presence sensor - Mounted on the jamb above the door, it detects the presence of a person standing in front of the door.
[edit] Technology
The operator is placed in the space above the sliding door.
A motor, geared down to get a lower speed and a higher torque, drives a pulley at one end of a belt. The door is clamped to the belt. To open the door, the motor turns the pulley, which in turn turns the belt, which in turn drags the door. To close the door, the reverse occurs.
Historically, elevator doors were opened by a set of mechanical linkages; the motor, geared down, would rotate linked arms, which in turn would drive the door.
[edit] External links
Operator manufacturers:
Safety:
- Overview of ANSI standards[6]
