relay 114 remains closed since contacts 117 are closed and switch 103 is closed valve 64 is also closed as described and at that time and thus the pressure in line 47 will increase until the setting of the relief valve 96 is overcome by the pressure being exposed to the pilot line 119 of valve 96 opening the valve 96 thus allows the hydraulic pressure in the head end of cylinder assembly 41 to be exhausted to the tank for return supply next continued extension of the cylinder assembly 36 causes the opening of the contacts in the limit switch 103 and therefore the current flowing to the control relay 114 is interrupted and thus the contacts 117 and 118 are opened and this results in the de energizing of the solenoid 101 with the solenoid 101 de energized the valve spring 97 will of course shift the spool of the valve 84 and return it to the position shown in fig3 and thus the cylinder assembly 36 will be caused to retract while the cylinder assembly 41 will be caused to extend and that reduces the hydraulic pressure in the line 67 and thus opens the valve 64 so that hydraulic pressure can pass through the valve 64 and into.