A compact latch system that snaps into position using geometry and spring force

This animation shows a spring-assisted toggle locking mechanism, where a hinged linkage moves past a center point to lock a sliding block firmly in position. As the pink lever is pushed, the blue jointed link transmits the motion to the yellow latch arm. A red compression spring provides the snap force needed to push the mechanism over center and hold it securely.

Components — The model includes the main base plate, the pink operating lever, the blue toggle link, the yellow latch arm, the red compression spring, the sliding green block, and the fixed gray housings on both sides.

How it works — When the pink lever is pushed downward, it drives the blue toggle link, which rotates the yellow latch arm toward the sliding green block. As the latch arm passes its geometric center point, the red spring pulls it into a stable locked position. To release, the lever is moved back, forcing the toggle out of the over-center condition and allowing the sliding block to move freely again.

Applications — Used in machine-tool fixtures, quick-release clamps, latching modules, mechanical locks, and precision holding devices.

Why it matters — The over-center toggle principle delivers strong locking with minimal force, creating a reliable, repeatable mechanism ideal for tight spaces.