What is a wind-up flea? - briefly
A wind‑up flea is a miniature mechanical toy that replicates a flea’s jumping motion when a spring is manually wound and then released. It generally comprises a coiled spring, a lever, and a tiny flea‑shaped body.
What is a wind-up flea? - in detail
A wind‑up flea is a miniature mechanical toy that imitates the movements of a flea. The device contains a tightly coiled spring that stores energy when manually turned. Release of the spring drives a gear train, which in turn moves a set of legs to produce a hopping motion.
The toy originated in the early nineteenth century, credited to French craftsmen who sought to demonstrate the capabilities of spring‑driven mechanisms. It quickly spread across Europe, becoming a common amusement for children and a curiosity for adults.
The internal mechanism consists of a mainspring, a series of reduction gears, and a cam that translates rotary motion into vertical leg displacement. The spring is wound by rotating a tiny knob attached to the axle. Once released, the gear train reduces speed while increasing torque, allowing the legs to lift and drop in rapid succession.
Construction typically employs thin sheets of tin or brass, formed into a compact body. Legs are fashioned from fine wire, often coated with enamel for durability and visual contrast. Decorative elements may include painted patterns or miniature accessories such as a tiny harness.
Variations include models that walk on a flat surface, versions that jump higher by altering the cam profile, and novelty designs featuring different animal shapes while retaining the same spring‑driven principle.
Contemporary reproductions are produced for collectors and museums. Modern versions may incorporate higher‑grade alloys and precision machining, but the fundamental principle—energy storage in a wound spring converted into rhythmic leg movement—remains unchanged.