Patent ID: 6305228
Filing Date: 2001-10-23
Classification: B66C

Abstract:
A pressure sensor device for detecting positive pressure and negative pressure in a pressure tube, and which is provided in a pressure-generating apparatus for placing the interior of a pressure tube in a negative pressure state using a negative pressure-generating valve for generating negative pressure and for placing the interior of a pressure tube in a positive pressure state using a positive pressure-generating valve for generating positive pressure, the pressure sensor device comprising:an input device for inputting from outside the pressure generating device an instruction signal in which a first state change-over from one of a high state having a relatively large value or a low state having a relatively small value to the other of the high state having a relatively large value or the low state having a relatively small value represents an instruction to generate negative pressure, and in which a second state change-over from the other of the high state having a relatively large value or the low state having a relatively small value to the one of the high state having a relatively large value or the low state having a relatively small value represents an instruction to generate positive pressure; anda control device for controlling the negative pressure-generating valve and the positive pressure-generating valve based on the first state change-over and the second state change-over of the instruction signal input by the inputting device.