Patent ID: 6739798
Filing Date: 2004-05-25
Classification: E04F

Abstract:
A rotary power trowel including radial blades pivotally supported for pivotal movement about radial axes to vary the pitch thereof, an operating handle extending upwardly from the trowel in inclined relation to enable an operator to control movement of the trowel, a flexible tension member extending along the operating handle and operatively associated with said blades to pivot the blades to vary their pitch, and a quick adjustment mechanism varying the pitch angle of said blades, said quick adjustment mechanism comprising a control lever having a central portion pivotally supported on said operating handle, said lever including a lower end extending below the operating handle and an upper end extending above the operating handle to a position to enable an operator to grasp the upper end of the control lever with one hand to exert force thereon to pivotally move said control lever, the lower end of said control lever being connected to said tension member through a mechanical advantage linkage to facilitate pivoting the blades from a flat pitch to an angled pitch by lifting the weight of the trowel, and a locking mechanism to releasably lock said control lever in pivotal relation to the operating handle in a position to lock said blades at a pitch angle, said mechanical advantage linkage including said control lever being pivotally connected to the operating handle at a pivot point closer to a lower end of said lever than to an upper end of said lever, a connecting rod connected to the lower end of the control lever, a pivot link pivotally mounted on said operating handle, said pivot link including a lower end pivotally connected to said connecting rod and an upper end connected to said tension member, said pivotal mounting of said link on said operating handle being located closer to said upper end of said link than to said lower end of said link, said upper end of said link being arcuate and provided with a groove receiving said flexible tension member, said flexible tension member being anchored to one end of said groove and tangentially engaging said groove during pivotal movement of the link.