M-blade snap action switch with optimal switch contact forces

A snap-action switch, comprising:

• a housing;
• a first bridge coupled to the housing;
• a second bridge coupled to the housing and spaced apart from the first bridge;
• an M-blade snap spring disposed within the housing, the M-blade snap spring including a closed end, a double-loop end, a first outer leg, a second outer leg, a first inner leg, a second inner leg, and a cross member, the double-loop end disposed opposite the closed end and between the first bridge and the second bridge, the double-loop end including a first loop and a second loop, the first outer leg coupled to the first inner leg to form the first loop of the double-loop end, the second outer leg coupled to the second inner leg to form the second loop of the double-loop end, the cross member coupled to the first outer leg and to the second outer leg to define the closed end, the first inner leg spaced apart from the second inner leg;
• and
• an actuation arm coupled to the housing and the first and second inner legs, and including a portion that extends between the first and second inner legs, the portion dimensioned to distort the M-blade snap spring such that the first and second inner legs are out of coplanar alignment with the first and second outer legs and the cross member, whereby the M-blade snap spring exhibits snap-action movement between a first switch position and a second switch position;
• wherein:
• the actuation arm is configured to selectively move the first and second inner legs between a first inner leg position and a second inner leg position, to thereby cause the M-blade snap spring to move, via snap action, between the first switch position and the second switch position, respectively,
• when the M-blade snap spring is in the first switch position, the double-loop end engages the first bridge and does not engage the second bridge, and
• when the M-blade snap spring is in the second switch position, the double-loop end engages the second bridge and does not engage the first bridge.

A snap-action switch, comprising:

• a housing;
• a first bridge coupled to the housing;
• a second bridge coupled to the housing and spaced apart from the first bridge;
• an M-blade snap spring disposed within the housing, the M-blade snap spring including a closed end, a double-loop end, a first outer leg, a second outer leg, a first inner leg, a second inner leg, and a cross member, the double-loop end disposed opposite the closed end and between the first bridge and the second bridge, the double-loop end including a first loop and a second loop, the first outer leg coupled to the first inner leg to form the first loop of the double-loop end, the second outer leg coupled to the second inner leg to form the second loop of the double-loop end, the cross member coupled to the first outer leg and to the second outer leg to define the closed end, the first inner leg spaced apart from the second inner leg;
• an actuation arm coupled to the housing and the first and second inner legs, and including a portion that extends between the first and second inner legs, the portion dimensioned to distort the M-blade snap spring such that the first and second inner legs are out of coplanar alignment with the first and second outer legs and the cross member, whereby the M-blade snap spring exhibits snap-action movement between a first switch position and a second switch position;
• an actuator extending through the housing and disposed adjacent the actuation arm, the actuator configured to selectively supply an actuation force to, and remove an actuation force from, the actuation arm, and thereby selectively move the M-blade snap spring, via snap-action, between the first switch position and the second switch position, respectively;
• a normally-closed contact coupled to the housing;
• and
• a normally-open contact coupled to the housing and spaced apart from the normally-closed contact,
• wherein:
• when the M-blade snap spring is in the first switch position, the M-blade snap spring is electrically connected to the normally-closed contact, and the double-loop end engages the first bridge and does not engage the second bridge, and
• when the M-blade snap spring is in the second switch position, the M-blade snap spring is electrically connected to the normally-open contact, and the double-loop end engages the second bridge and does not engage the first bridge.