Method and apparatus for finishing concrete

Abstract

A power trowel is provided for finishing concrete. The trowel can be used to finish concrete at different stages of hardening. The handle of the trowel is rotated both to adjust the speed of rotation of the trowel blades and the cant of the trowel blades.

1 . A power trowel including
 (a) a frame including a hub;   (b) a pole having
 (i) a distal end shaped to be grasped as a handle, 
 (ii) a proximate end attached to said frame, 
 (iii) a longitudinal axis extending from said distal end to said proximate end, said pole rotatable along its entire length about said longitudinal axis; 
   (c) a plurality of spaced apart blades pivotally mounted on and radially extending from said hub, each of said blades having a lower surface area;   (d) a transmission assembly mounted on said frame and operatively associated with said blades to pivot and alter the cant of said blades;   (e) a control unit to activate said transmission assembly to pivot and alter the cant of said blades; and,   (f) an engine mounted on said frame, having a throttle, and operatively associated with and rotating said hub.   
   
   
       2 . The power trowel of  claim 1  wherein said control unit comprises a linkage unit interconnecting said transmission assembly and said proximate end of said pole such that when said handle is rotated in a selected direction, said linkage unit is actuated and activates said transmission assembly to pivot and alter the cant of said blades. 
   
   
       3 . The power trowel of  claim 1  wherein said transmission assembly includes at least one slotted plate and at least one bearing with an arcuate outer surface and shaped and dimensioned to move along a slot in said plate when said plate is rotatably displaced, said bearing when displaced acting to displace a control member in said transmission assembly to alter the can of said blades. 
   
   
       4 . A transmission including
 (a) at least one slotted plate; and,   (b) at least one bearing with an arcuate outer surface and shaped and dimensioned to move along a slot in said plate when said plate is rotatably displaced, said bearing when displaced acting to displace a control member in said transmission.   
   
   
       5 . The power trowel of  claim 1  wherein said motor is a variable speed electric motor. 
   
   
       6 . A method for finishing concrete, including the steps of
 (a) providing a power trowel including
 (i) a frame including a hub; 
 (ii) a pole having
 a distal end shaped to be grasped as a handle, 
 a proximate end attached to said frame, 
 a longitudinal axis extending from said distal end to said proximate end, 
 said pole rotatable along its entire length about said longitudinal axis; 
 
 (iii) a plurality of spaced apart blades pivotally mounted on and radially extending from said hub, each of said blades having a lower surface area; 
 (iv) a transmission assembly mounted on said frame and operatively associated with said blades to pivot and alter the cant of said blades; 
 (v) a control unit operated by said rotating said pole to activate said transmission assembly to pivot and alter the cant of said blades; and, 
 (vi) an engine mounted on said frame, having a throttle, and operatively associated with and rotating said hub; 
   (b) placing said power trowel on concrete;   (c) operating said engine; and   (d) rotating said pole to operate said control unit to alter the cant of said blades.