The button switch may be the simplest component in the electrical circuit, but it controls the lifeblood of the entire control circuit, so it is also called the "master switch". Understanding all kinds of button switches and using them skillfully and flexibly can make us get twice the result with half the effort.
Button switches are used to switch on or off small current circuits in a short period of time, and are mainly used in electrical control circuits. The current allowed to flow through the button switch is small, generally not more than 5A.
The button is generally composed of a button cap, a return spring, a bridge-type moving contact, a static contact, a pillar connecting rod, and a housing. The opening and closing state of the contacts when the button is not subjected to external force (that is, static), is divided into a stop button (that is, a dynamic break button), a start button (that is, a dynamic close button) and a reset button (that is, a combination of a dynamic close and a dynamic break. integrated button). When the button is under the action of external force, the opening and closing state of the contact changes: the normally open contact under static state is closed, and the normally closed contact under static state is open.
A rotor on which a moving contact is attached is received and rotatably held in a body, and a knob is received and held in the body side by side with the rotor and is movable. A plurality of first and second teeth are circumferentially staggered with each other on an outer perimeter surface of the rotor near one end and near the other end, respectively, in the direction of the axis of the rotor to project from the surface. An inclined surface is formed in each of the first and second teeth. A projecting part is formed on the knob to project toward the rotor. In response to a depression of the knob, the projecting part pushes the inclined surface of the second teeth to rotate the rotor and, in response to a return of the knob, pushes the inclined surface of the first teeth to rotate the rotor.
The invention provides a push-button switch including: a star wheel which is rotated by a constant angular step in one direction by a depression of a push button that automatically returns; an indenter which is pressed against the outer periphery of the star wheel by a spring; a contact which is attached so as to corotate with the star wheel, and which serves as a movable contact; and terminals with which the contact is contacted in accordance with a rotation angle, and which serve as stationary contacts. A small projection having a rounded tip end is disposed in each of ridge portions of the star wheel. Even when the slope of each ridge portion does not have a large inclination angle, the star wheel is prevented from being stopped at a position where the ridge portion is opposed to the indenter.
