摘要 |
<p>The rake (1) is automatically cleaned of twigs, brambles and other rubbish by a bar (2), movable along the tines by a piston (4) with a large head in opposition to a return spring (3). The piston can be so mounted that when its head strikes the ground the bar is thrust between the rake teeth to remove the rubbish, after which the spring returns it to a position above the rake.</p> |