| 摘要 |
PURPOSE:To make a precise sensing of a piston stroke by a method wherein a nut is engaged with the piston in a main body of the cylinder by screw, the threaded shaft of the nut is rotatably and slidably fitted to the main body of the cylinder to restrict the same, and means for sensing an amount of rotation of the shaft is cooperatively coupled to the threaded shaft. CONSTITUTION:A piston 9 is integrally formed with the piston rod 10 and the threaded shaft 14 of the nut means 24 extends through the piston. The nut means 24 holds several balls 26 rotating in the helical groove of the threaded shaft 14, both of them are combined to constitute a ball screw 27. An output shaft 17 of the threaded shaft 14 is coupled to an operated part 38 of the sensor means 29 for the amount of rotation through a flexible coupling 39. Both the piston 8 and the nut 25 are integrally moved and the threaded shaft 14 is rotated along with their movement. The amount of rotation is sensed by the detector 29. |
