To stop a housing box at an optional position in a long period at the low cost by switching the connecting destination of an air connection switching part with the control signal of a control part to control the sending quantity of compressed air to control the extending/reducing quantity of a cylinder to reduce an installing space and to efficiently use a compresser and the control part.
The compressed air sending port 101 of one compresser 1 is connected to the air introducing port 201 of one air connection switching part 2 through an air pipe 61. The part 2 can be connect-switched to two system paths and is provided with first and second air sending ports 202 and 203. A housing 51 is attached to the movable part 412 of a first cylinder 41 and a housing 52 is attached to the movable part 422 of a first cylinder 42. The first air sending port 202 and an air introducing port 411 are connected through an air pipe 63 with each other. One control part 3 is connected to the compressor 1 and the part 3 is connected to the part 2.
SASAKI SEIICHI
KUJIRAOKA AKIHIKO
