Abstract: A recoil starter for a backpack-type power working machine which is capable of easily and smoothly performed the starting operation even when the working machine is kept on the operator's back irrespective of differences in the operator's build. This recoil starter comprises a recoil grip which is attached to a distal end portion of a recoil rope extended out of the main body of the recoil starter, wherein the recoil grip is designed such that it can be anchored to a recoil grip-supporting member to be positioned close to an operator's waist and that it can be pulled out in front of the operator from the recoil grip-supporting member. The recoil grip-supporting member is made optionally alterable in position.

Abstract: A starter which is capable of having an operator easily perform the starting operation of a backpack-type power working machine while shouldering it, is lighter in weight and cheaper in manufacturing cost, is relatively free from trouble, and can not easily be damaged even if a portion of the starter is caught by the branch of a tree. In this starter, a recoil handle attached to one end portion of the recoil rope is placed remote from the main body of the starter by a predetermined distance and adapted to be supported by a handle-supporting member provided at a specific portion of the working machine; and an extended portion of the recoil rope which is located between the main body and the handle-supporting member is loosely sheathed by a flexible guide pipe, one end of which being fixed, and the other end being made free.

Abstract: A recoil starter for a backpack-type power working machine which is capable of easily and smoothly performed the starting operation even when the working machine is kept on the operator's back irrespective of differences in the operator's build. This recoil starter comprises a recoil grip which is attached to a distal end portion of a recoil rope extended out of the main body of the recoil starter, wherein the recoil grip is designed such that it can be anchored to a recoil grip-supporting member to be positioned close to an operator's waist and that it can be pulled out in front of the operator from the recoil grip-supporting member. The recoil grip-supporting member is made optionally alterable in position.

Abstract: A portable power tool includes an internal combustion engine that includes a crankshaft in which a load applied thereto is unevenly distributed along the axis of the crankshaft with respect to the axis of the reciprocating movement of a piston. The portable power tool also includes operational members that are driven by the internal combustion engine, a rotational body fixed to an end of the crankshaft to which a smaller component of the load is applied, and a balancing weight provided on the rotational body for absorbing vibrations generated by the reciprocating movement of the piston. The centroid of the balancing weight is disposed at an angular position from 140 degrees to 180 degrees with respect to the axis of the reciprocating movement of the piston in a rotational direction of the rotational body, when the piston is positioned at a top dead center.

Abstract: A starter which is capable of having an operator easily perform the starting operation of a backpack-type power working machine while shouldering it, is lighter in weight and cheaper in manufacturing cost, is relatively free from trouble, and can not easily be damaged even if a portion of the starter is caught by the branch of a tree. In this starter, a recoil handle attached to one end portion of the recoil rope is placed remote from the main body of the starter by a predetermined distance and adapted to be supported by a handle-supporting member provided at a specific portion of the working machine; and an extended portion of the recoil rope which is located between the main body and the handle-supporting member is loosely sheathed by a flexible guide pipe, one end of which being fixed, and the other end being made free.

Abstract: A portable power tool includes an internal combustion engine that includes a crankshaft in which a load applied thereto is unevenly distributed along the axis of the crankshaft with respect to the axis of the reciprocating movement of a piston. The portable power tool also includes operational members that are driven by the internal combustion engine, a rotational body fixed to an end of the crankshaft to which a smaller component of the load is applied, and a balancing weight provided on the rotational body for absorbing vibrations generated by the reciprocating movement of the piston. The centroid of the balancing weight is disposed at an angular position from 140 degrees to 180 degrees with respect to the axis of the reciprocating movement of the piston in a rotational direction of the rotational body, when the piston is positioned at a top dead center.

Abstract: A cutting blade safety cover for covering a rear portion of a cutting blade of a portable trimmer. The safety cover includes a roof plate portion and a skirt portion suspended from the roof plate portion. The roof plate portion is separated at a radially middle location thereof into a radially inner portion and a radially outer portion. The radially inner portion and the radially outer portion are detachably attached to each other so that the radially outer portion is replaceable with another radially outer portion having a dimension suitable for covering a cutting blade of a different dimension.

Abstract: A cutting blade safety cover for covering a rear portion of a cutting blade of a portable trimmer. The safety cover includes a roof plate portion and a skirt portion suspended from the roof plate portion. The roof plate portion is separated at a radially middle location thereof into a radially inner portion and a radially outer portion. The radially inner portion and the radially outer portion are detachably attached to each other so that the radially outer portion is replaceable with another radially outer portion having a dimension suitable for covering a cutting blade of a different dimension.