Abstract: A machine tool is equipped with a feed screw unit for relatively moving a tool and a work to be worked and a contact detection means for detecting contact between the tool and the work, which is provided for a feed screw unit. With the feed screw unit is engaged a nut member and the nut member is provided with a minutely expandable member capable of being minutely or finely expanded or contracted in an axial direction of the nut member. The minutely expandable member is provided with a minutely expandable means, and the contact detection means is provided for the minutely expandable member. The contact detection means and the minutely expandable means are disposed in parallel or in series, or in combination, to each other with respect to an axial direction of a feed shaft.

Abstract: A linear motion slide unit comprises a slider axially movably mounted on a guide rail by a number of rolling members. A sealing device comprises a pair of end plates mounted at both ends of the slider and a connection plate, connecting the pair of end plates, with the connection plate disposed between the slider and the guide rail in the axial direction. First sealing members are disposed on the end plates where the end plates face the guide rail. Second sealing members extend along the axial direction of the connection plate.

Abstract: In the ball screw guide unit of the invention, since a guide rail is formed of a channel bar having a groove, and a ball screw shaft is engaged with a movable member which is reciprocatively movable in the groove along a lengthwise direction of the guide rail, so that the centroid of the guide rail is adjacent to the axis of the ball screw shaft. Therefore, when a pretension is applied to the ball screw shaft, a straightness of the guide rail is not impaired and a feed accuracy of the movable member can be maintained. Further, the guide rial may be provided at its lower and side surfaces with reference surfaces used for adjusting parallelism between the guide rail and the axis of the ball screw shaft, in which case assembly and adjustment of the table can be performed more easily.

Abstract: A ball screw comprising a threaded rod and a ball nut making a rectilinear motion around the rod as the rod is rotated. A first load ball groove and a second load groove which have an offset relation to each other are formed in the inner surface of the ball nut. A pre-load is imparted to ball bearings rolling in these two load grooves. The ball nut has a resilient portion between the first and second load ball grooves. The resilient portion can be displaced axially. Any excessive pre-load created by the error introduced either in the lead of the ball-rolling groove or in the lead of the first or second load ball groove is absorbed by the resilient portion. Consequently, the novel ball screw is superior in accuracy to the prior art ball screw, and is easier to fabricate.

Abstract: A reciprocating device has a construction, in which a slider is formed by fixing a table member to a bearing casing which is movable inside a track bed having a C-shaped section in a longitudinal direction thereof, and a continuous drive is disposed along the track bed for reciprocating the slider. A weight and sizes of the device can be reduced, and reciprocating motion without a pitching motion can be achieved. Accordingly, the invention can prevent generation of uncomfortable noises during a movement of the slider, and also can prevent reduction of durability of the device which may be caused by irregular wear of a bearing for guiding the slider.