Contact Lever Assembly With Damped Spring Attachment for Switch Reliability
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Solution Overview
Problem
Conventional contact lever assemblies in electrical switches for power tools experience wear and vibratory movement due to direct contact between the return spring and contact lever, leading to poor electrical connectivity, arcing, and potential fusion of contact members.
Innovation Solution
An attachment member is introduced to indirectly attach the biasing element to the contact lever, providing a protective layer and reducing vibratory movement, which is configured from materials like plastic, rubber, or polymers to alleviate wear and ensure a cleaner contact between the movable and stationary contact members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the return spring is rigidly secured directly to the contact lever, then the structure is simple and easy to manufacture, but wear occurs between the return spring and contact lever due to repeated movement
Solution Approach 1:
An attachment member is introduced as an intermediary component between the return spring and contact lever. This attachment member has a first end attached to the contact lever and a second end to which the return spring is secured. This intermediary structure prevents direct contact and wear between the return spring and contact lever, thereby improving reliability while maintaining manufacturing simplicity.
2Force
If the return spring is rigidly secured to the contact lever, then the biasing force is strong and reliable, but vibratory movement occurs between the movable contact member and stationary contact member
Solution Approach 1:
The attachment member serves as a mediator that absorbs and dampens vibratory movements. By positioning the attachment member between the return spring and contact lever, it reduces the transmission of vibrations to the movable contact member, thereby preventing arcing and maintaining reliable electrical connectivity while preserving the necessary biasing force.
Solution Approach 2:
The attachment member acts as a cushioning element that is pre-positioned to absorb vibratory shocks before they can cause damage to the contact members. This beforehand cushioning prevents arcing and maintains electrical connectivity by reducing the intensity of vibratory movements during switch operation.
3Device complexity
If the return spring is directly attached to the contact lever, then the device complexity is low, but the contact members experience arcing and potential fusion
Solution Approach 1:
The attachment member is introduced as a simple intermediary component that prevents direct contact between the return spring and contact lever. This additional element minimally increases device complexity but effectively reduces arcing and sparking by damping vibratory movements, thereby protecting the contact members from fusion.
4Device complexity
If the return spring is rigidly secured to the contact lever, then the assembly is compact and simple, but wear and vibratory movement reduce switch reliability
Solution Approach 1:
The attachment member serves as a simple intermediary component that maintains the compact and simple structural design while significantly improving switch reliability. By positioning this attachment member between the return spring and contact lever, it reduces both wear and vibratory movement, thereby enhancing overall switch reliability without substantially increasing structural complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The attachment member reduces vibratory bouncing and wear, ensuring a firmer contact and preventing arcing and fusion of contact members, while also protecting the biasing element from heat damage caused by high currents, thereby improving electrical connectivity and switch reliability.
Implementation Method 1
a biasing element configured for biasing the contact lever towards the second configuration... said biasing element including a first end attached to a first attachment point in connection with a portion of the contact lever
Implementation Method 2
an attachment member configured for attachment with the contact lever whereby when attached to the contact lever, said attachment member is configured for operation as the first attachment point... configured for alleviating vibratory movement of the contact lever
Data Source
AI summary
An electrical switch including a switch housing, a switch circuit disposed within the switch housing. The switch circuit including includes a movable contact member mounted on a contact lever and a stationary contact member. The contact lever is configured for operable-interaction with an actuator. The actuator is configured for movement along an actuator movement axis relative to the contact lever between at least one of an OFF position whereby the contact lever is configured for arrangement in to the first configuration whereby the switch circuit is opened, and, an ON position in which the contact lever is configured for arrangement in to the second configuration whereby the switch circuit is closed.