Reuleaux-triangle intermittent mechanisms

The Reuleaux triangle is a convex triangle-like shape, each side of which is an arc centered on the opposite vertex. Any curve of constant width can form a rotor within a square, a shape that can perform a complete rotation while staying within the square and at all times touching all four sides of the square.

Intermittent motion mechanisms were first used in sewing machines, nowadays they are used in many mechanical applications to index film in cameras, projectors, and in film processing equipment…

Reuleaux mechanism