PURPOSE: To relieve shock at the time of start by compressing the gas from some of the compression chambers in No.1 discharge chamber and a back pressure chamber, and by permitting gas from the other compression chambers to be free from compression.
CONSTITUTION: A discharge chamber 23 on rear side is divided into No.1 discharge chamber 45 and No.2 discharge chamber 46 by a partition wall 6a, in which a valve chest 47 and a by-pass 48 are furnished. A valve elment 51 is provided in this valve chest 47 to divide it into a back pressure chamber 53 and a spring chamber 59. Accordingly the discharge gas from some of the compression chambers of the cylinders is compressed in No.1 discharge chamber 45 and back pressure chamber 53 to be put in working condition, while the discharge gas from the other compression chambers will be free of compression to remain in non-working condition. This will reduce the start torque of the compressor to lead to lessening the shock likely to be generated associate therewith.
DEGUCHI HIROYUKI
KOBAYASHI HISAO
Next Patent: CUTTING PLOTTER DEVICE