Abstract: A plant cutter apparatus has a tubular handling rod having a first end portion and a second end portion. A drive shaft extends through the handling rod and is mounted for undergoing rotation. A drive source unit is mounted on the first end portion of the handling rod for rotationally driving the drive shaft. A cutter blade is connected to the drive shaft for rotation therewith. A clutch case has a first mounting portion connected to the first end portion of the handling rod, a flexible coupling portion extending from the first mounting portion toward the drive source unit, and a second mounting portion extending from the flexible coupling portion and connected to drive source unit. The second mounting portion has an axial fitting hole for receiving the first end portion of the handling rod so that the first end portion of the handling rod is axially slid able therein.

Abstract: A plant cutter apparatus has a one-piece handling rod having an outer pipe portion, an inner pipe portion disposed concentrically within the outer pipe portion, and first, second and third radial stay portions extending between and interconnecting the outer pipe portion and the inner pipe portion. The first, second and third radial stay portions are arranged at non-equal angular intervals such that an angle &thgr;1 formed between the first and second stay portions, an angle &thgr;2 formed between the second and third stay portions, and an angle &thgr;3 formed between the third and first stay portions differ from each other. A drive shaft extends through the inner pipe portion and is rotatably supported within the inner pipe portion via a bushing disposed between the drive shaft and the inner pipe portion. A drive source unit is mounted at one end of the handling rod for rotating the drive shaft.

Abstract: Drive shaft of a plant cutter apparatus includes an elongate main shaft portion made of a titanium alloy, and end shaft portions made of steel and integrally joined to the opposite ends of the main shaft portion. The titanium alloy has substantially the same mechanical strengths as the steel. Therefore, the titanium-alloy-made main shaft portion can secure rigidity that is normally required of the plant cutter's drive shaft, and can also reduce the weight of the drive shaft to thereby minimize unwanted sagging-induced vibrations of the drive shaft caused by the shaft's own weight.

Abstract: A drive shaft to be inserted into a pipe-shaped operating pole for use in a portable working machine is provided. The drive shaft has at least one resin bush integrally formed on its outer peripheral surface. Thus integrally forming the bush on the drive shaft allows agreement between the axis center of the operating pole, the axis center of the bush and the axis center of the drive shaft, preventing the change of position of the bush during the use of the working machine, and resulting in the reduction of vibration of the drive shaft with the simple configuration.

Abstract: A handle holder for mounting a U-shaped handle to an operating pole of a bush cutting machine. The handle holder has a first holding member and a second holding member. The first holding member has an operating pole insertion hole for insertion of the operating pole therethrough, an oblique groove, and a handle receiving groove for receiving the base of the handle. The second holding member has a wedge and a handle retaining groove. The wedge is fitted into the groove of the first holding member to fix the first holding member to the operating pole. The handle is interposed and held between the handle receiving groove of the first holding member and the handle retaining groove of the second holding member to be fixed to the first holding member.

Abstract: In a plant cutter apparatus, a handling rod includes an outer pipe portion, an inner pipe portion and three radial stay portions interconnecting the outer and inner pipe portions. The three stay portions are arranged, about an axial centerline of the rod, at non-equal angular intervals in such a manner that angles formed between the three stay portions differ from each other. Thus, the rod has a cross-sectional configuration asymmetric about the axial centerline. Geometric moment of inertia of the thus-constructed handling rod takes different values in all angular positions about the axial centerline, and thus the inherent vibrating frequency of the rod also takes different values in all the angular positions. Consequently, the rod's inherent vibrating frequency coincides with a frequency of vibrations transmitted from a drive source unit in only one of the angular positions, so that resonant vibrations of the handling rod can be avoided easily.

Abstract: Plant cutter apparatus includes a handling rod, a drive source unit mounted on one end portion of the handling rod via a clutch case, and a cutter blade mounted on the other end portion of the handling rod for being rotated by activation of the drive source unit. With the handling rod inserted in an axial loosely-fitting hole of the clutch case, the one end portion of the handling rod abuts at its end surface against an abutting region formed on the way through the loosely-fitting hole. The drive source unit is supported by the end surface of the handling rod via a drive-source mounting portion of the clutch case. The drive source unit is allowed to freely vibrate about the one end portion of the handling rod supporting the unit, so that a flexible coupling portion of the clutch case can perform a vibration attenuation function to reduce vibrations transmitted from the drive source unit to the handling rod.

Abstract: Drive shaft of a plant cutter apparatus includes an elongate main shaft portion made of a titanium alloy, and end shaft portions made of steel and integrally joined to the opposite ends of the main shaft portion. The titanium alloy has substantially the same mechanical strengths as the steel. Therefore, the titanium-alloy-made main shaft portion can secure rigidity that is normally required of the plant cutter's drive shaft, and can also reduce the weight of the drive shaft to thereby minimize unwanted sagging-induced vibrations of the drive shaft caused by the shaft's own weight.

Abstract: A bush cutting machine including a prime mover, a cutter and a handle fixed to an operation rod. The handle has left and right end portions carrying grips. Each grip is mounted at a center of gravity of a sum of a mass of a handle portion between a fixed point and a distal end of the handle and a mass of the grip.

Abstract: A handle holder for mounting a U-shaped handle to an operating pole of a bush cutting machine. The handle holder has a first holding member and a second holding member. The first holding member has an operating pole insertion hole for insertion of the operating pole therethrough, an oblique groove, and a handle receiving groove for receiving the base of the handle. The second holding member has a wedge and a handle retaining groove. The wedge is fitted into the groove of the first holding member to fix the first holding member to the operating pole. The handle is interposed and held between the handle receiving groove of the first holding member and the handle retaining groove of the second holding member to be fixed to the first holding member.

Abstract: A snow shoveling machine comprising an engine and an auger housing accommodating therein an auger paddle. The engine is actuated to thereby rotate the auger paddle. The auger housing includes an upper half and a lower half. The upper half is made from resin. The lower half is formed of a sheet of steel. The upper and lower halves are connected to each other through a connecting member. The connecting member serves a function of reinforcing the auger housing. As snow collected by the auger paddle is thrown upwardly into a snow throwing aperture formed in the upper half, some snow fails to enter the aperture. The connecting member serves to allow such snow to fall to the auger paddle.