Position-sensing apparatus

Abstract

A machine tool spindle (10), rotatable in a housing (11), is adapted to receive, as an alternative to a cutting tool, a probe (12) having a stylus (14) whereby to sense a workpiece (15) for the purpose of measuring it. On sensing the workpiece (15) the probe (12) generates a signal which is transmitted to a fixed location (X) on the housing (11). The probe (12) has a body (13) secured to the spindle (10) for rotation therewith, such rotation being required for certain measuring manouvres. To cope with the transmission of the signal (17) from the rotating probe (12) to the fixed location (X), the signal (17) is transmitted through the intermediary of a sleeve (19) supported on the probe body (13) such that the body (13) can rotate while the sleeve (19) is held still by an axially disengageable mechanical connector (21) connecting the sleeve (19) to the housing (11). The transmission of the signal (17) takes place through a rotation-accommodating first inductive coupling (28) between the probe body (13) and the sleeve (19), and by a rotationally fixed but axially disengageable second inductive coupling (30) between the sleeve (19) and the housing (11). The probe and sleeve assembly (12,19) is connectable to and disconnectable from the spindle (10) by a transfer mechanism (24). The connector (21) and the second coupling (30) are engaged and disengaged accordingly. The assembly (12,19) may include a duct (31) for transmission of a cleaning fluid from the housing (11) to the sensing end (14A) of the stylus (14).

Dependencies are inferred from the claim text.