Search results
Results from the WOW.Com Content Network
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.
The majority of the operators open the door directly or through an arm. Overhead concealed mount—the operator is mounted above the door and rotates the door directly, through its pivot. Surface mount, push (scissor arm)—the operator is mounted on the wall above the door, on the approach side and pushes the door with a linkage of 2 arms.
Raynor — the company's line of garage door openers for professional installers. This line of professional installers is slightly less common than LiftMaster. Craftsman — re-branded Chamberlain models sold at Sears. Those products have a "139" model prefix to denote that the Chamberlain Group made them for Sears.
The operator is placed in the space above the sliding door. An electric 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.
In electric power distribution, automatic circuit reclosers (ACRs) are a class of switchgear designed for use on overhead electricity distribution networks to detect and interrupt transient faults. Also known as reclosers or autoreclosers , ACRs are essentially rated circuit breakers with integrated current and voltage sensors and a protection ...
An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, electric multiple units, trolleybuses or trams. The generic term used by the International Union of Railways for the technology is overhead line . [ 1 ]
Electric overhead traveling cranes or EOT cranes are a common type of overhead crane, also called bridge cranes. They consist of parallel runways, much akin to rails of a railroad, with a traveling bridge spanning the gap. [1] EOT cranes are specifically powered by electricity.
A trolley pole is not attached to the overhead wire. The pole sits atop a sprung base on the roof of the vehicle, with springs providing the pressure to keep the trolley wheel or shoe in contact with the wire. If the pole is made of wood, a cable brings the electric current down to the vehicle. A metal pole may use such a cable, or may itself ...