Abstract: A rotor has an interior free from invasion of water and is resistant to deformation from applied stresses normally encountered during the operation of a vacuum pump. The rotor comprises a rotor shell formed to conform to an outline of lobes and side-plates for covering transverse ends of the rotor shell. A rotation shaft is secured to the side-plates. A hollow section is formed by the rotor shell and the side-plates which is under a vacuum environment.

Abstract: A vacuum pump for use in an evacuating system for a semiconductor fabrication apparatus is operated at a steady rotational speed to evacuate the semiconductor fabrication apparatus. Then, in response to a signal indicative of an operating state of the semiconductor fabrication apparatus which does not need to be evacuated, the rotational speed of the vacuum pump is reduced to an idling rotational speed, thereby to lower electric energy consumption by the vacuum pump.

Abstract: A glue gun type gluing apparatus has glue guns 8a and 8b for applying glue to a gluing area in a joint flap 2 of a corrugated board sheet 1 for manufacturing a box, which runs on a box manufacturing line, a sheet end detection sensor 3 for detecting the front and rear ends of the corrugated board sheet 1, an encoder 7 for measuring the travel distance of the corrugated board sheet 1, and a control unit 9 for controlling the operation of the glue guns 8a and 8b. The control unit 9 learns and stores the position of gluing area on the basis of the information from the sheet end detection sensor 3 and the encoder 7 while the corrugated board sheet 1 is run at a low speed, and restricts the acquisition of detection signals by the sensor 3 during the time from the passing of the end point of the joint flap 2 to the arrival of the start point of the next joint flap 2.

Abstract: A press roll elevator in a double facer is disclosed including press roll groups each having a plurality of press rolls for a corrugated cardboard sheet traveling in a first direction through the double facer. The press rolls are rotatably supported between tip end portions of respective pairs of arms which swing in the sheet's direction of travel about fulcrum shafts mounted on both side frames of the double facer. The fulcrum shafts are disposed at intervals along the sheet's direction of travel, and the press rolls are elevated and lowered by swing motion of the respective pairs of arms. Common rails reciprocated along the sheet's direction of travel and having protrusions extending therefrom abut against the respective arms causing the swing motion.