Patent ID: 6925789

Claim:
A cutting apparatus for a lawn mower, the lawn mower including a vertical rotating shaft, said cutting apparatus comprising: a base plate adapted to be connected fixedly to the rotating shaft and having a side surface and a rotating axis, said base plate being elongated and having two blade-retaining holes formed respectively through two ends of said base plate; an abutment post extending integrally from said side surface of said base plate and formed with an annular surface coaxial with said rotating axis of said base plate; a pair of first and second guiding blocks extending integrally from said side surface of said base plate and located at two opposite sides of said abutment post, each of said first and second guiding blocks being formed with a line-receiving slot therethrough that has an inner end proximate to said abutment post, and an outer end distal from said abutment post, said line-receiving slots in said first and second guiding blocks being coplanar, said line-receiving slots in said first and second guiding blocks being straight and parallel to each other, said rotating axis of said base plate being located between imaginary extension lines of said line-receiving slots in said first and second guiding blocks, said first and second guiding blocks being disposed between said blade-retaining holes in said base plate; and a cutting unit including: a nylon line that extends through said line-receiving slots in said first and second guiding blocks and that has a pair of first and second block-engaging line portions received respectively within said line-receiving slots in said first and second guiding blocks, a curved post-engaging line portion abutting against said annular surface of said abutment post, a generally straight first connecting line portion interconnecting said first block-engaging line portion and said post-engaging line portion so as to form an acute angle between said first block-engaging line portion and said first connecting line portion, thereby preventing said nylon line from being removed from said first and second guiding blocks by centrifugal force of said nylon line when the rotating shaft rotates, a generally straight second connecting line portion interconnecting said second block-engaging line portion and said post-engaging line portion, and a blade assembly having two blade members, each of which has a cutting blade portion and a mounting blade portion that are interconnected fixedly, said mounting blade portions of said blade members being mounted respectively and detachably within said blade-retaining holes in said base plate, said cutting blade portions extending from said mounting blade portions away from each other, whereby one of said nylon line and said blade assembly of said cutting unit can be removed from said base plate during use.