Quick adjustment mechanism for blade pitch of concrete power trowel

摘要

A rotary power trowel machine for finishing concrete surfaces and more particularly to a quick adjustment mechanism for the pitch of the blades. The quick adjustment mechanism includes a control lever mounted on the operating handle of the trowel in a position to be easily grasped and operated by a trowel operator. The control lever changes the blade pitch through a mechanical advantage linkage which reduces the force applied to the control lever to adjust the blade pitch. The control lever includes a locking mechanism to lock the control handle and linkage in selected positions to lock the blades at a desired pitch angle. The locking mechanism includes a semicircular guide mounted on the trowel operating handle and extending through openings in the control lever. A locking device on the control lever lockingly engages the guide and is selectively locked and released from an upper end of the control lever.