Cam and roller overcenter handle mechanism

An overcenter manually operable actuator comprising:

• a housing ;
• a lever having a first end portion and a second end portion, the first end portion being pivotally mounted on the housing, the second end portion being arranged for receiving a manually applied force for swinging the lever between positions at opposite sides of a central top dead center position, the lever pivoting about a first axis in response to the manually applied force;
• a cam member having a cam surface including a first convex surface portion and a second convex surface portion, the first and second convex surface portions forming a cusp therebetween;
• a cam follower member having a cam follower surface, one of the cam and cam follower members being carried by the lever for pivoting about the first axis and the other of the cam and cam follower members being mounted for pivoting about a second axis offset from the first axis;
• and
• a biasing member that urges the cam follower surface against the cam surface in pressure contact, the pressure contact cooperating with the cam follower member to pivot the cam member about the first axis when the cusp contacts the cam follower surface corresponding to the central top dead center position of the lever, whereby the lever is biased away from the central top dead center position.

An overcenter mechanism comprising:

• a housing;
• a first shaft mounted on the housing, the first shaft defining a first axis;
• a second shaft mounted on the housing, the second shaft defining a second axis that parallels the first axis;
• a lever attached to the first shaft, the lever pivoting about the first axis in response to a force applied to the lever;
• a cam attached to the first shaft, the cam pivotable about the first axis, the cam having a cam surface including a first surface portion and a second surface portion, the first and second surface portions forming a cusp therebetween;
• a cam follower including a roller that defines a cam follower surface, the cam follower pivoting about the second axis;
• and
• a biasing member that urges the cam follower surface against the cam surface in pressure contact, the pressure contact cooperating with the cam follower during pivoting of the lever to generate torque on the cam until the cam follower surface approaches the cusp, the pressure contact creating an instability about the cusp when the cam follower surface contacts the cusp, such that the torque pivots the cam so the cam follower moves away from the cusp.

An overcenter mechanism comprising:

• a housing having a first shaft mount with a first axis and a second shaft mount with a second axis that parallels the first axis;
• a first shaft received within the first shaft mount and being aligned with the first axis;
• a second shaft received within the second shaft mount and being aligned with the second axis;
• a lever having a first end and a second end, the first end being attached to the first shaft, the second end being arranged for receiving an applied force, the lever pivoting about the first axis in response to the applied force;
• a cam that is attached to the first shaft, the cam pivoting about the first axis, the cam having a cam surface including a first surface portion and a second surface portion, the first and second surface portions forming a cusp therebetween;
• a cam follower including a roller that defines a cam follower surface, the cam follower pivoting about the second axis;
• and
• a biasing member that urges the cam follower surface against the cam surface in pressure contact, the pressure contact cooperating with the cam follower to pivot the cam about the first axis when the cusp contacts the cam follower surface.