| 摘要 |
A miniature snap action electrical switch has a member fixedly supported in the switch housing which serves both as a common terminal for the switch and a mount for the switch blade structure. The switch blade structure includes the switch blade and a pivotal cam, and the switch blade has an integral tongue between two arched legs connecting a bridging portion at one end and a contact portion at the other. The tongue mounts in a notch in one face of the combination member, and the pivotal cam has a cam edge which engages the combination member on its opposite face. The switch blade is connected with the pivotal cam at the end of such cam opposite to the cam edge and is tensioned when so assembled in a mounted free position for the switch. When the bridging portion is depressed by an operating force in a switching operation, the cam pivots in a rolling action and travels a small linear dimension on the face of the combination member while the tongue of the blade is in a fixed mounted position on the opposite face of such member. The blade operates with a light force and yet exerts a large contact force at the contact and corresponding terminal. There is a minumum change in the length of the arched blade when it is tensioned or stressed as the blade is moved through an operating cycle. This minimum change contributes to lesser metal fatigue in blade and a longer life for the switch, while the large contact force at the terminal and a light operating force provide important characteristics in the switch.
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