Hydraulic lift system for wheel stretchers

• US 3,393,004 A
• Filed: 10/06/1966
• Issued: 07/16/1968
• Est. Priority Date: 10/06/1966
• Status: Expired due to Term

• Current Assignee: Simmons Company (Serta Simmons Bedding LLC)
• Original Assignee: Leonard Williams Earl
• Inventors: LEONARD WILLIAMS EARL
• Application Number:
  US04/584,755
• Time in Patent Office: 649 Days
• US Class Current: 296/20
• CPC Class Codes: A61G 7/005 tiltable around transverse horizontal axis, e.g. for Trendelenburg position rocking beds for physical therapy A61H1/003; hanging patient inclined downwardly for drawing him out A61H2203/0493

Claims

1. FOR USE IN A WHEELED STRETCHER HAVING A WHEELED UNDERCARRIAGE, A PATIENT-SUPPORTING PLATFORM, AND TWO LONGITUDINALLY-SPACED ADJUSTABLE-HEIGHT SUPPORTS ON SAID UNDERCARRIAGE EACH HAVING AT ITS UPPER END A PIVOTAL CONNECTION WITH THE PLATFORM ON AN AXIS EXTENDING TRANSVERSELY OF THE PLATFORM:

AN IMPROVED LIFT MECHANISM WHICH PERMITS THE DIRECT PLACEMENT OF THE PATIENT-SUPPORTING PLATFORM IN ENDWISE TILT IN EITHER DIRECTION FROM ANY PREVIOUS POSITION;

THE IMPROVED LIFT MECHANISM COMPRISING (1) A HYDRAULIC LIFT CLYINDER FOR ADJUSTING EACH SUPPORT, (2) A SEPARATE POSITIVE-DISPLACEMENT PUMP CONNECTED TO EACH SUCH CYLINDER, (3) MEANS FOR OPERATING THE PUMPS IN UNISON, (4) A RESERVOIR FROM WHICH THE PUMPS DRAW, (5) A RELIEF VALVE OPENING AUTOMATICALLY FROM EACH CYLINDER TO THE RESERVOIR WHEN THE CYLINDER REACHES A PREDETERMINED EXTENSION, AND (6) A SEPARATE HAND-OPERATED NORMALLY-CLOSED VALVE IN FLUID COMMUNICATION WITH EACH CYLINDER AND THE RESERVOIR TO VENT ITS ASSOCIATED CYLINDER TO THE RESERVOIR.