Probe with retractable tip

摘要

The test needle (4,4a) of the test instrument is carried within a sheath (5) which is spring loaded to a normally retracted position within the insulated body (1). When a trigger (7) is squeezed a lever (13) presses ball bearings (10) in a trough (9) causing the sheath (5) to move forward and expose the test needle (4a). Electrical connection is made through a cable (2).