Abstract: Manual tool used for trimming mold flash and protuberances from a tire has a handle with ends which are slotted to receive mounting flanges of a undulated sheet metal blade. The blade is so folded that its undulations comprise closely spaced ridges which extend from front to rear, are open on their underside and are united by narrow intervening webs. The underside of the lead edge of the blade is sloped along an arc and/or angle providing the blade with recesses in said leading edge between the ridges. The recesses have sharp cutting edges which cut entering flash close to the tire surface, the open under side of the ridges on either side of the webs providing clearance for missed flash and trimmings so that the tool blade is not raised off the tire surface in use of the tool.

Abstract: Rotary motion is converted to linear motion by multiple thread sets which cooperate to provide precise control of the amount of rotary motion thus converted. As applied to a precision positioning device for a tool, blade or other object, the thread sets are preferably arranged in a serial and/or telescoped configuration. A relatively simple precision hand tool positioning device is realized by having one thread set arranged in a common direction but reduced pitch relative to the other set. The finiteness of the object positioning is further enhanced by moving it with respect to an inclined plane. A retaining device for gripping the element to be moved is directly associated with a shank having the smaller pitched thread set thereon. The shank is prevented from rotating but allowed to move linearly relative to a housing and the threads thereof engage a spindle which has another set of threads for engaging the housing. A calibrated indicator of the shank position in easily readable format is provided.