Source: {"pile_set_name": "USPTO Backgrounds"}

Computer numerical control or “CNC” milling machines often must be precisely “leveled” in a manner which causes the vertical orientations of support contact points upon the undersurface of the machine's base or chassis to coincide with a horizontal plane. Ideally, leveling procedures performed upon such machines eliminate any warping, deflection, or distortion of any of such support contact points away from the horizontal plane. Such machine leveling is known to be facilitated or accomplished by adapting a milling machine's floor contacting feet or pedestals to function as vertically extendable and retractable hydraulic cylinders. Operation of such cylinder pedestals through selective injections and ejections of hydraulic fluid to and from the cylinders' interior fluid filled volumes is known to align a machine's base with the horizontal plane. Where such cylinder pedestals are arranged beneath a heavy milling center machine in a support matrix, operation of the cylinder pedestals either individually or in groupings gives rise to significant difficulties, complexities, and challenges. In such leveling operations, various groupings of cylinder pedestals or individual cylinder pedestals are alternatively raised, lowered, locked against fluid flow, and opened for equipment “floating” interchange of fluid volumes. In any such equipment leveling task, a multitude of such alternative operations directed to the cylinder pedestals may be required to be performed. Known assemblies, machinery and equipment which facilitate such a operations are cumbersome in use and time consuming.
The instant inventive assembly for hydraulic fluid actuated machine leveling solves or ameliorates such difficulties and challenges by providing and associating with a machine supporting matrix of hydraulic cylinder configured pedestals a specialized network of hydraulic fluid carrying conduits wherein hydraulic fluid flow and pressure is controlled by incorporation of a specialized combination of shutoff valves and a variable relief valve.