Hydraulic system with regenerative position

• US 3,273,468 A
• Filed: 01/26/1965
• Issued: 09/20/1966
• Est. Priority Date: 01/26/1965
• Status: Expired due to Term

• Current Assignee: John D. Allen
• Original Assignee: John D. Allen
• Inventors: Allen, John D.
• Application Number:
  US04/428,032
• Time in Patent Office: 602 Days
• US Class Current: 91/420
• CPC Class Codes: F15B 13/01 Locking-valves or other detent i.e. load-holding devices
• CPC Class Codes: Y10T 137/8671 With annular passage [e.g., spool]
• CPC Class Codes: Y10T 137/87241 Biased closed

Claims

1. A HYDRAULIC SYSTEM FOR OPERATING FROM A PUMP, A PISTON AND CYLINDER IN WHICH THE CYLINDER HAS FIRST AND SECOND PORTS ON OPPOSITE SIDES OF THE PORTION AND THE PISTON HAS A LARGER EXPOSED AREA ON ONE SIDE, SAID SYSTEM COMPRISING:

A SPOOL VALVE COMPRISING A VALVE BODY HAVING A BORE THEREIN AND A PLURALITY OF RECESSES INTERSECTING SAID BORE AT SPACED LOCATIONS THEREALONG AND INCLUDING A PAIR OF PUMP RECESSES FOR CONNECTING TO THE PUMP AND RETURN RECESSES FOR CONNECTION TO A RETURN LINE AND ADDITIONAL RECESSES, AND A SPOOL SLIDABLY RECEIVED IN SAID BORE AND HAVING A PLURALITY OF LONGITUDINALLY SPACED LANDS THEREON FOR SEALING ENGAGEMENT WITH THE BORE BETWEEN SAID RECESSES AND HAVING REDUCED DIAMETER PORTIONS BETWEEN ITS LANDS;

A FIRST NORMALLY-CLOSED CHECK VALVE CONNECTED TO ONE OF SAID ADDITIONAL RECESSES IN THE SPOOL VALVE BODY AND HAVING A PORT FOR CONNECTION TO THE CYLINDER AT ONE SIDE OF THE PISTON, A FIRST PRESSURE RESPONSIVE MEMBER CONNECTED TO ANOTHER OF SAID ADDITIONAL RECESSES IN THE SPOOL VALVE BODY AND MOVABLE IN RESPONSE TO FLUID PRESSURE THEREAT TO OPEN SAID CHECK VALVE;

A SECOND NORMALLY-CLOSED CHECK VALVE CONNECTED TO ANOTHER OF SAID ADDITIONAL RECESSES IN THE SPOOL VALVE BODY AND HAVING A PORT FOR CONNECTION TO THE CYLINDER AT THE OPPOSITE SIDE OF THE PISTON, A SECOND PRESSURE RESPONSIVE MEMBER CONNECTED TO ANOTHER OF SAID ADDITIONAL RECESSES IN THE SPOOL VALVE BODY AND MOVBLE IN RESPONSE TO FLUID PRESSURE THEREAT TO OPEN SAID SECOND CHECK VALVE;