| 摘要 |
931,014. Concrete surfacing machines. KALMAN FLOOR CO. Inc. Dec. 6, 1960 [Dec. 14, 1959], No. 42025/60. Class 107. A trowelling machine for concrete and like surfaces comprises a plurality of trowelling blades, motor means connected to the blades to rotate them relative to the motor means, a handle connected to the motor means, second motor means including a rotatable shaft mounted on one of the blades and an eccentric mass secured to the shaft. As shown, blades 30 are driven by a motor 16 through reduction gear 26 and each blade supports a motor 34 by means of a bracket 36 bolted to a plate welded to the upper face of the blade. An eccentric mass 44 is mounted on the shaft 42 of the motor and vibratory forces are transmitted to the blade through a bearing (not shown) mounted in the bracket 36. The supply of electric power for the motors 34 is controlled by a switch 46 on the handle 10 of the machine. In an alternative embodiment a motor is mounted on one blade only and counterweights on the other blades. |
