What is the latch?
The latch is part of the door that prevents the door from opening. In order to be a latch item, it must be placed in place. This separates the latch screw from locks or hooks, where the fastening mechanism is simply placed in the holder. The actual screw can be in any number of forms, from the standard connecting element to the knob to the blind. The western screws are one of the oldest forms of the introduction of doors and are still very common.
The screws were used as a way to keep the door closed until people use the door. The simplest and one of the earliest forms of the screw is called the crossbar. These were simply long bars that slipped into parentheses on the door. When they are in place, the door is prevented. This method not only keeps the door closed, but also locks it. This form of latch is still common in many places, including many public bathrooms. When the door began to internalize their fastening structure, the latch became part of the inner functioning of the doorbutton. Modern screws work in the same way as their historical counterparts - the only difference is the method used to slip them. In the old days the human force moved the screw in and out of the position on the door. With modern door buttons it moves the mechanical effect with a screw.
When a typical door button turns, the mechanical effect pulls out the latch screw from the door jam. The inside of the button will usually contain a spring that pushes the latch back to the place if the door button is released. When the door is locked, the button turns and the latch is released. If the door is open and locked, the spring allows the latch to slip back even when the button turns; This allows one to close the locked door, but not to reopen.
When the door has two screws that stick to the door in separate holes, usually one Will lock and one will not. The one that makes the lock is the lock and the one whoRIK is not a latch screw. This setting is common for higher safety doors, such as outer doors or dead screw systems. In many cases, the system of two screws does not allow a person to close the locked door as a standard door button, because the locking screw does not move at all.