Abstract: In a surface texture measuring instrument, a measurement arm includes: a first measurement arm that is supported by a bracket around a support shaft movably in a circular movement in a casing; and a second measurement arm having styluses that are attachably and detachably provided to an end of the first measurement arm via an attachment-detachment mechanism, the attachment-detachment mechanism being arranged in the casing. A displacement detector includes: a scale provided to the measurement arm; and a detection head provided to the bracket to face the scale. A detecting surface of the scale is on an axis of the measurement arm and on a plane of the circular movement of the measurement arm.

Abstract: In a surface texture measuring instrument, a measurement arm includes: a first measurement arm that is supported by a bracket around a support shaft movably in a circular movement in a casing; and a second measurement arm having styluses that are attachably and detachably provided to an end of the first measurement arm via an attachment-detachment mechanism, the attachment-detachment mechanism being arranged in the casing. A displacement detector includes: a scale provided to the measurement arm; and a detection head provided to the bracket to face the scale. A detecting surface of the scale is on an axis of the measurement arm and on a plane of the circular movement of the measurement arm.

Abstract: A surface texture measuring instrument has a pre-load leaf spring (41, 42) for biasing a detector (10) having a skid (14) at a distal end thereof, a pre-load force controller (47) for controlling a pre-load force of the pre-load leaf spring (41, 42), and a stopper (50) for restricting movement of the detector (10) in a biasing direction when a predetermined pre-load force is applied to the detector (10) by the pre-load force controller (47). In conducting a skidless measurement, the detector (10) is locked by applying the predetermined pre-load force to the detector (10) by the pre-load force controller (47). In conducting a skid measurement, the pre-load force less than the predetermined value is applied to the detector (10) by the pre-load force controller (47).

Abstract: A slider holding a measuring tool moves along an approximately reverse U-shaped guide rail provided in parallel with a moving direction of the measuring tool without being rotated. Accordingly, a cross section of the guide rail can be enlarged without increasing the size of the entirety of a drive unit. As a result, high rigidity can be obtained while reducing the size and weight of the drive unit as compared to a conventional arrangement having two shafts. Further, linearity of the slider and the measuring tool moving along a reference surface of the guide rail can be attained with high accuracy. Further, since a pre-load means for biasing the slider toward a guide rail is provided, a position or orientation of the slider and the measuring tool can be stabilized, thus securely repeating movement of the measuring tool.