Abstract: A mower of the centrifugal cord type is provided with an automatic adjustment of the length of cutting cord, in which the centrifugal force of the rapidly whirling cord end acts on an arm which snubs the cord and prevents further cord from being paid out, until the wearing away of the cord end reduces the force and permits further cord to be paid out by the centrifugal force until the force again reaches the critical value for snubbing the cord.

Abstract: An X-ray tire inspection machine for rapid and precise determination of accuracy of placement of internal elements, by visual or automated sensing of dimensions and of uniformity, precisely places each of a random succession of pneumatic tires for highway vehicles from the smallest to the largest sizes, scans the entirety of bead-to-bead sectors or any part of each sector, without gaps or significant overlaps, and displays all or any desired portions of the X-ray shadow pictures as a succession of still pictures, or senses automatically the presence of irregularities of various kinds in any desired locations. Precise placement of tires is accomplished by gripping of the tread of a horizontal tire by four spools having upper and lower flanges positively moved toward one another at a fixed speed until they grip the shoulders of the tread.