The Button Contact is used to open, close or change the path of a circuit.
A single contact is either opened (off) or closed (on).
Momentary Contact;
A momentary contact is a contact that is switched for as long as the button is held in.
When the button is released it returns to its normal state.
Maintained Contact;
A maintained contact is a mechanically latched contact that changes state each time it is
pushed.
Push once for on. Push again for off.
Normally Open Contact;
A momentary contact that closes when pushed.
Normally Closed Contact;
A momentary contact that opens when pushed.
Two Position Push-Pull;
A maintained mechanical contact
Three Position Push Pull;
Dual momentary contact; this button is spring held in a center position.
Pulling out changes the state of one set of contacts.
Pushing in changes the state of a 2nd set of contacts.
Momentary buttons are used to control devices where more than one source is needed in the control of such a device.
You can series together as many normally closed buttons as you like. The path can be broken by any one of them.
You can parallel as many normally open buttons as you like. The path is complete if any of them is pushed.