| 摘要 |
<p>A concrete finishing machine having a rotatable trowel blade assembly (11) and a mechanism (27, 29, 33) for controllably adjusting the pitch of the trowel blades (15) relative to a wet concrete surface (19) on which the blades rest. Manual pivoting of a control lever (25) controllably adjusts the trowel blade pitch and, in doing so, automatically increases or decreases the amount of blade surface contacting the concrete surface (19), and correspondingly lowers or raises the machine relative to the surface (19). The contacting blade surface supports the machine's entire weight. A special counterbalancing apparatus that includes, for example, a compressed coil spring (51), biases the control lever (25) so as to compensate for the machine's weight and permits an operator to adjust the blade pitch with substantially less force than otherwise would be required.</p> |
