Search results
Results from the WOW.Com Content Network
Permanently engaged—the motor driven mechanism (the opener portion) is always joined to the closer (if present) and to the door. When opening the door manually, the user is also driving the opener portion, so the opening is rough and noisy. Electro-hydraulic types are inherently quiet and smooth during manual opening, as the motor and pump ...
Aluminium gates, being lightweight, work well with brushless motor operators, as the motors do not have to work as hard to maneuver the gates. This not only enhances the overall performance and reliability of the gate system but also contributes to energy efficiency, leading to cost savings in the long run.
A door closer is a mechanical device that regulates the speed and action of a door’s swing. [1] Manual closers store the force used to open the door in some type of spring and reuse it to close the door. Automatic types use electricity to regulate door swing behavior. Door closers can be linked to a building's fire and security alarm systems. [2]
The electric overhead garage door opener was invented by C.G. Johnson in 1926 in Hartford City, Indiana. [1] Electric Garage Door openers did not become popular until Era Meter Company of Chicago offered one after World War II where the overhead garage door could be opened via a key pad located on a post at the end of the driveway or a switch inside the garage.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Crash bar doors in a school, with upper vertical rod latches. A crash bar (also known as a panic exit device, panic bar, or bump bar) [1] [2] is a type of door opening mechanism which allows users to open a door by pushing a bar.
Simple remote control systems use a fixed code word; the code word that opens the gate today will also open the gate tomorrow. An attacker with an appropriate receiver could discover the code word and use it to gain access sometime later. More sophisticated remote control systems use a rolling code (or hopping code) that changes for every use.
A typical single-car garage roller door has a preloaded spring inside the rolling mechanism. The spring reduces the effort required to open the door. Oversized roller doors in commercial premises are not sprung (except in the US), and a manual pulley and chain system or a geared motor is used to raise and lower (roll up and roll down) the door.