Fluid is drawn in from tank 1 through suction pipe a to hydraulic pump 2 from where it enters delivery pipeline b. In the left-hand position (as shown) of lever 3, turning about fixed axis A, fluid from the delivery pipeline passes through valve 4 to the left end of cylinder 5, moving piston 6, piston rod 7 and table 8, attached to the piston rod, to the right. From the right end of cylinder 5, fluid is discharged through valve 4 to tank 1. In the right-hand position of lever 3, fluid is delivered to the right end of cylinder 5, moving table 8 to the left. In this case, fluid from the left end of cylinder 5 is discharged through valve 4 to tank 1. Lever 3 of valve 4 is turned by trip dogs c mounted on travelling machine tool table 8. Catch d serves to eliminate uncertainty in the positions of lever 3. The amount of fluid delivered to cylinder 5 and, consequently, the speed of travel of table 8 is regulated by means of the pump. Surplus fluid is discharged back to tank 1 by relief valve 10. Owing to the different diameters of the rod on the two ends of piston 6 and, therefore, different effective areas at the two ends, table 8 has different speeds on its forward and return strokes.
$4154$CHP,Dr$