Patent ID: 7134519

Claim:
A working machine comprising: a base machine, which is formed in such a manner that an upper rotating body is rotatably mounted on a crawler type lower traveling body around a vertical shaft, the base machine including a working attachment comprising a boom, an arm, a bucket, and driving motors for the boom, arm and bucket, said upper rotating body having an operator's cab on an upper portion of said upper rotating body, said upper rotating body having functional apparatus which requires maintenance comprising an openable guard cover, which covers the apparatus, attached to an outer peripheral portion of the upper rotating body of said working machine; a window provided in said guard cover for maintenance of said apparatus; a window cover provided with said guard cover, said window cover being provided to open or close said window independently of opening or closing of said guard cover; and a guard cover locking mechanism, provided within said guard cover, which locks said guard cover in a closed mode, said guard cover locking mechanism being located within said guard cover to allow a locking and an unlocking operation from the outside of said guard cover only through said window.