Abstract: The bucket includes a bottom plate including a first deepest portion, a bracket provided on a back surface of the bottom plate, and a front lip. The bottom plate includes a first inclined portion on a side where the bracket is attached. A first reference straight line is defined that passes through a pivot axis of a bucket and a tip end of the front lip. A second reference straight line is defined that is orthogonal to the first reference straight line and passes through the first deepest portion. An angle formed between the second reference straight line and the front lip is smaller than an angle formed between the second reference straight line and the first inclined portion. An intersection point between the first reference straight line and the second reference straight line is located close to the front lip on the first reference straight line.

Abstract: There is provided with a compressor comprising: a compressor main body in which fluid inhaled from an inhale port is compressed, and the compressed fluid is exhausted from an exhaust port; and a pressure retaining device where provided on the exhaust port side of the compressor main body, and retaining pressure on the exhaust port side, wherein the pressure retaining device comprises: a valve body communicating with the exhaust port; an urging member normally urging the valve body into a direction to be closed; and a back-pressure means where an intermediate pressure between the inhale port and the exhaust port of the compressor main body is introduced as back pressure which affects the valve body, and wherein the valve body of the pressure retaining device is openable according to difference between pressure at the exhaust port, and the intermediate pressure of the back-pressure means and force by the urging member.