Compressed air driven disposable hand tool having a rotor with radially moving vanes

A method for utilizing fluid to cause a shaft to rotate, including the steps of:

• forming a rotor to include a trunk and a plurality of vanes,
• connecting each vane through a hinge to the trunk, the hinge allowing each said vane to pivot with respect to the trunk between a first collapsed position and a second extended position,
• orienting the rotor within a hollow cavity,
• providing an inlet fluid port passing into the cavity from a rear plug,
• providing an outlet fluid port passing into the cavity parallel to an axis of rotor rotation from the rear plug,
• coupling the rotor to a means to extract rotational energy from the rotor,
• coupling the inlet fluid port to a source of fluid,
• directing fluid from the source of fluid through the inlet fluid ports and into contact with the vanes of the rotor, causing the rotor to rotate,
• biasing the vanes toward the second position such that the vanes extend away from the trunk unless forces are applied against the vanes, causing the vanes to pivot toward the first position adjacent the trunk,
• providing a recess in the trunk for each vane, the recess sized to receive the vanes therein when said vanes are pivoted into said first position, and
• regulating a speed of said rotor by:
• shaping said cavity with a circular cross-section and
• sizing said cavity with a diameter less than a diameter scribed by tips of the vanes most distant from the trunk when the vanes are in the second position, such that the vanes can contact the cavity at all times where frictional forces increase with increasing velocity and increasing pressure.