Abstract: An apparatus for monitoring the depth of tread on a tire being buffed includes a sensing device, for example, a magnetic sensor, mounted to a reciprocating motion carrier. The carrier is driven by a drive wheel that is in contact with the tire being buffed. The carrier is movably mounted to float over the surface of the tire, that is, accommodate variations in the tire surface, with a guide wheel following the tire surface to maintain the sensor at a constant distance from the tire surface. The sensor on the carrier reciprocally traverses the crown of the tire as the tire rotates to obtain actual values for the thickness of the rubber above the belts over the whole surface of the crown.

Abstract: A quick adjusting arm for an envelope spreader includes a bar member mounted to an articulated arm of the envelope spreader and a sleeve with a hook installed on the bar member. The bar member has a plurality of adjusting holes to position the sleeve at a selected position. The sleeve includes a single positioning hole, and a quick release pin, for example, a spring ball pin, is inserted through the positioning hole and the selected adjusting hole.