Abstract: A tire changing machine for breaking tire beads on a wheel rim having a drop center is disclosed. The machine includes a bead breaker mechanism including upper and lower bead breaking shoes, driving levers for each of the bead breaking shoes, and horizontally and vertically adjustable mechanism for positioning the upper bead breaker, which mechanism is frictionally locked where manually adjusted. The tire changing machine also includes a rack and pinion drive arrangement for centrally located rotating tire tool driving post. The rack is driven by the upper bead breaking drive lever. Dual power cylinders are provided, one to drive the lower bead breaker drive lever and one to drive the upper bead breaker drive lever. The drive levers are driven bi-directionally by their respective cylinders. The center post is also driven bi-directionally by the upper bead breaker power cylinder.

Abstract: A back-washable filtering element, especially for use with pumps, and more particularly for use with pumps that handle liquids with solid material entrained therein, consists of a helical coil spring disposed in a flow path for the liquid to be filtered. A movable element in the flow path is mechanically connected to the spring and compresses it axially under the effect of the back washing liquid to automatically reduce the flow capacity. The resultant "shrugging" of the spring also permits it to clear itself of filtered material to facilitate the back-washing.