Hospital bedrail counterbalance unit

Claim 1

A COUNTERBALANCE UNIT FOR BALANCING THE WEIGHT OF A BEDRAIL PIVOTALLY SUPPORTED IN A LONGITUDINALLY EXTENDING POSITION ALONG ONE SIDE OF A HOSPITAL BED AND EXTENDING BETWEEN THE HEADBOARD AND FOOTBOARD THEREOF, SAID BEDRAIL INCLUDING AT LEAST ONE LONGITUDINALLY EXTENDING RIGID MEMBER AND BEING CAPABLE OF OCCUPYING A FIRST UPWARDLY EXTENDING PROTECTIVE POSITION AND IN ANY ONE OF A NUMBER OF SECOND NON-PROTECTIVE POSITIONS IN WHICH IT IS DISPOSED OUTWARDLY FROM SAID BED A GREATER DISTANCE THAN WHEN IN SAID FIRST POSITION, SAID UNIT COMPRISING: A RIGID ARM HAVING FIRST AND SECOND END PORTIONS; MEANS FOR PIVOTALLY CONNECTING SAID FIRST END PORTION OF SAID ARM TO SAID RIGID MEMBER; MEANS FOR REMOVABLY HOLDING SAID BEDRAIL IN SAID FIRST POSITION; A HOUSING; MEANS FOR SUPPORTING SAID HOUSING FROM SAID HEADBOARD; AN ELONGATE CAM MEMBER HAVING FIRST AND SECOND END PORTIONS AND A BORE FORMED THEREIN THAT EXTENDS TRANSVERSELY THROUGH SAID CAM MEMBER ADJACENT SAID SECOND END PORTION; A SHAFT SUPPORTED FROM SAID HOUSING THAT EXTENDS THROUGH SAID TRANSVERSE BORE AND PIVOTALLY SUPPORTS SAID CAM MEMBER; MEANS SUPPORTING SAID SECOND END PORTION OF SAID ARM FROM A SIDE OF SAID CAM MEMBER AND NORMAL TO SAID SHAFT; A CABLE HAVING FIRST AND SECOND END PORTIONS; MEANS FOR AFFIXING SAID FIRST END PORTION OF SAID CABLE TO SAID CAM MEMBER, WITH A PART OF SAID CABLE ADJACENT SAID FIRST END PORTION EXTENDING OVER SAID FIRST END PORTION OF SAID CAM, WITH SAID FIRST END PORTION OF SAID CAM BEING UPWARDLY DISPOSED WHEN SAID BEDRAIL IS IN SAID FIRST POSITION; AND SPRING MEANS IN SAID HOUSING CONNECTED TO SAID SECOND END PORTION OF SAID CABLE FOR EXERTING A FORCE OF CONSTANTLY INCREASING MAGNITUDE ON SAID CABLE AS SAID CAM MEMBER PIVOTS DUE TO MOVEMENT OF SAID BEDRAIL FROM SAID FIRST TO ONE OF SAID SECOND POSITIONS, WITH SAID CAM BEING OF SUCH SHAPE THAT AS IT PIVOTS TO INCREASE SAID FORCE ON SAID SPRING ONLY THAT PORTION OF SAID FORCE REQUIRED TO COUNTERBALANCE SAID BEDRAIL IN THE PARTICULAR ONE OF SAID SECOND POSITIONS IN WHICH SAID BEDRAIL MAY BE DISPOSED IS TRANSFERRED TO SAID ARM.