Working part structure of lawnmower

1. A working part structure of a lawnmower, comprising:

a disk rotatably supported by a main body of the lawnmower and configured to be rotated by a power source;

a blade having a base end portion rotatably attached to an outer peripheral part of the disk via a pivot shaft and a free end portion configured to protrude radially outward from an outer peripheral edge of the disk;

a blade guard having a base end portion rotatably supported by the pivot shaft and a free end portion overlying the free end portion of the blade; and

a retaining feature configured to substantially prevent a relavive rotation between the blade and the blade guard,

wherin the retaining feature comprises a blade holder including a holder main body interposed between the blade and the disk and rotatably supported by the pivot shaft and a pair of side upright pieces which are beent from either side edge of the holder main body and extend past either side edge of the blade and either side edge of the blade guard.

2. The working part structure of a lawnmower according to claim 1 , wherein the blade holder further includes an end upright piece which is bent from a base end edge of the holder main body and extends past a base end edge of the blade and/or a base end edge of the blade guard.

3. The working part structure of a lawnmower according to claim 1 , wherein the blade guard is interposed between the disk and the blade, and the blade holder is integrally formed with the blade guard.

4. The working part structure of a lawnmower according to claim 1 , wherein the blade guard is positioned on top of the blade.

5. The working part structure of a lawnmower according to claim 1 , wherein the free end portion of the blade guard projects radially outward beyond a free end edge of the blade.

6. The working part structure of a lawnmower according to claim 1 , wherein the blade guard is made of a material softer than that of the blade.

7. The working part structure of a lawnmower according to claim 1 , wherein the retaining feature is configured to substantially prevent the relative rotation between the free end portion of the blade and the free end portion of the blade guard around the pivot shaft.

8. A working part structure of a lawnmower, comprising:

a disk rotatably supported by a main body of the lawnmower and configured to be rotated by a power source;

a blade having a base end portion rotatably attached to an outer peripheral part of the disk via a pivot shaft and a free end portion configured to protrude radially outward from an outer peripheral edge of the disk;

a blade guard having a base end portion rotatably supported by the pivot shaft and a free end portion overlying the free end portion of the blade; and

a retaining feature configured to substantially prevent a relative rotation between the blade and the blade guard,

wherein the blade guard is tapered toward a free end thereof, and is narrower than the blade at least in the free end portion thereof.

9. The working part structure of a lawnmower comprising:

a disk rotatably supported by a main body of the lawnmower and configured to be rotated by a power source;

a blade having a base end portion rotatably attached to an outer peripheral part of the disk via a pivot shaft and a free end portion configured to protrude radially outward from an outer peripheral edge of the disk; and

a blade guard having a base end portion rotatably supported by the pivot shaft and a free end portion overlying a free end portion of the blade,

wherein the pivot shaft comprises a threaded bolt passed through the base end portions of the blade and the blade guard, and a flanged nut is fastened to the threaded bolt, the flanged nut being provided with a spacer collar.