This mechanism works much like a two button click pen: the main rod slides forward and catches on a yellow latch, and a separate side button releases that latch so the green spring can drive the rod back to its starting position. The layout is compact, fast acting, and relies only on a few sliding surfaces and a single compression spring.

Components — The assembly includes a cylindrical outer tube, an inner sliding rod, a green compression spring seated at the rear, a yellow latch plate that moves sideways, and a small red and green side button mounted in a window on the tube. The spring loads the rod backward while the latch holds it forward when engaged.

How it works — Pushing the rod from left to right forces its rear shoulder past the yellow latch, where it snaps into a small recess. At that moment the latch holds the rod fully forward against the spring’s force. Tapping the side button pushes the latch inward, clearing the recess and allowing the compressed green spring to drive the rod back to its original position. The latch immediately resets, ready to catch the rod again on the next forward stroke.

Applications — Similar latch and spring arrangements appear in click pens, small tools, extendable probes, sliding catches, compact ejection systems, and any device needing a quick lock and instant release in a straight line.

Why it matters — The mechanism shows how a simple lateral latch can manage a strong axial spring load reliably. It delivers a positive lock, a clean release, and repeatable operation without cams, gears, or complex linkages.