Abstract: A plate roofing material is divided into an exterior portion which is exposed when a roof is covered with a plate roofing material and an overlap portion which is concealed under an exterior portion of a plate roofing material superimposed on the overlap portion of the plate roofing material. At least one longitudinal groove is formed in the surface of the exterior portion. The longitudinal groove has wide side surface parts alternating with narrow side surface parts with sidewalls formed of a plurality of stepped portions. The longitudinal groove has a linear bottom part having an approximately constant depth and is approximately V-shaped in cross section.

Abstract: A lawn mower has a cutter blade rotatable in a substantially horizontal plane, and a cutter housing with the cutter blade being rotatably accommodated therein, the cutter housing comprising an upper wall having a raised scroll, and a circumferential wall having a discharge duct contiguous to the scroll and defining a discharge port. A first inner member is detachably disposed along inner surfaces of the upper and circumferential walls of the cutter housing, the first inner member having an inner surface of arcuate cross section. A second inner member is detachably disposed in the discharge duct contiguously to the first inner member in closing relationship to the discharge port, the second inner member being separate from the first inner member and having an inner surface of arcuate cross section.

Abstract: A power lawn mower of a mulching type with no opening for releasing mowed pieces sidewardly and having a housing with a short peripheral side wall with an inwardly protruding at a rear substantially half portion of a lower edge of the peripheral wall in the direction of forward movement of the lawn mower. The protruding portion temporarily retains mowed lawn pieces, or cuttings within the housing for chopping by a cutter rotatable in the housing. Chopped lawn pieces or cuttings are dropped through a lawn drop opening defined by the peripheral wall and deposited between blades of the cut lawn grass. The moved pieces are chopped to a moderate extent and dropped through the blades of the cut lawn grass to promote growth of the lawn grass.

Abstract: A hub clutch for locking or unlocking a wheel drive shaft to or form a hub clutch housing, comprises: a drive gear fixed to the wheel drive shaft; a slide gear slidably engaged or disengaged with or from the drive gear to lock or unlock the wheel drive shaft to or form the hub clutch housing; an elastic member for urging the slide gear into engagement or disengagement with or from the slide gear; a pressure source for supplying pressure into a pressure chamber formed between the wheel drive shaft and the hub clutch housing to shift the slide gear against an elastic force of the elastic member; and in particular a pressure supplementing switch for supplementing pressure supplied from the pressure source into the pressure chamber, whenever pressure within the pressure chamber drops below a predetermined value.