主权项 |
1. A weed trimmer head comprising;
a driving shaft having a first end; a second end and a threaded portion along an intermediate segment thereof between said first end and said second end; said first end having a bearing assembly and a power driving element mounted thereto for driving a rotation thereof by rotation of said power driving element, and said second end having a sole plate connected thereto and a power transmission connection connecting said sole plate to said driving shaft for driving a rotation of said sole plate by said rotation of said driving shaft and said power driving element; said sole plate having a diameter; a circumference; a plurality of pivot pins extending therefrom near said circumference; each of said pivot pins having a large end connected to said sole plate and a small end extending away from said sole plate parallel with said driving shaft, toward said first end of said driving shaft; a plurality of cutting blades pivotally mounted to said plurality of pivot pins each of said cutting blades having a thickness; a wingnut plate mounted to said driving shaft; said wingnut plate having a disc-like portion; a flat surface facing said small ends of said pivot pins, and wing blades extending from an outside surface thereof toward said power driving element, opposite from said flat surface; said wingnut plate having a threaded hole in said disc-like portion; said threaded hole being mounted to said threaded portion of said driving shaft; such that said wingnut plate is movable along said threaded portion of said driving shaft, by rotation of said wingnut plate about said driving shaft, relative to said sole plate; said threaded portion of said driving shaft having a sufficient length such that said wingnut plate is movable toward and away from said sole plate and said small ends of said pivot pins by way of said threaded hole and said threaded portion a distance that is greater than said thickness of one of said cutting blades for selectively contacting said small ends of said pivot pins for retaining said cutting blades to said pivot pins, or for exposing said small ends of said pivot pins for replacing one of said cutting blades from one of said pivot pins. |