An extremely safe skin-pricker device in the form of an open-ended tubular shell which carries an open-coil actuator spring which when released by a latchable trigger pushes an actuator shaft to move and cause the pricker needle to travel not only to an intermediate position of relieved stress but also to travel the short distance for the pricking procedure, but then, by the spring's over-travel movement permitted by its open-coil nature, the spring pulls on the shaft to withdraw the needle safely inwardly of a cover-cap which during the pricking is retained on the open end of the shell.
