Hydraulic door closer

Claim 1

A DOOR CHECK APPARATUS OR THE LIKE INCLUDING A HYDRAULIC CYLINDER; A PISTON MEMBER IN SAID CYLINDER AND FRICTIONALLY CONTACTING THE CYLINDER; A PISTON ROD MEMBER ROTATABLY ENGAGING THE PISTON MEMBER AND EXTENDING OUT THROUGH ONE END OF THE CYLINDER; A MOUNTING MEANS CONNECTED TO THE OUTWARDLY EXTENDING END OF THE ROD MEMBER TO HOLD THE ROD MEMBER AGAINST ROTATION WHEN THE APPARATUS IS IN USE; SEAL MEANS BETWEEN THE CYLINDER AND THE ROD MEMBER AT SAID END OF THE CYLINDER; MEANS PROVIDING A FLUID-TIGHT CLOSURE AT THE OTHER END OF THE CYLINDER; A MOUNTING BRACKET ADAPTED TO BE FIXEDLY MOUNTED; MEANS ROTATABLY CONNECTING THE BRACKET AND THE CYLINDER WHEREBY THE CYLINDER MAY BE ROTATED WITH RESPECT TO THE BRACKET ABOUT THE AXIS OF THE CYLINDER; AND A FLUID PASSAGEWAY EXTENDING BETWEEN OPPOSITE SIDES OF THE PISTON MEMBER AND INCLUDING A GROOVE; IN ONE OF THE MEMBERS, SAID FLUID PASSAGEWAY BEING ADJUSTABLE IN SIZE BY THE ROTATION OF ONE MEMBER WITH RESPECT TO THE OTHER TO VARY THE DEGREE OF RESTRICTION TO THE FLOW OF FLUID THERETHROUGH, WHEREBY WITH SAID APPARATUS MOUNTED IN A FIXED POSITION BY SAID MOUNTING MEANS AND SAID MOUNTING BRACKET THE SPEED AT WHICH THE FLUID FLOWS THROUGH SAID PASSAGEWAY MAY BE ADJUSTED BY ROTATING THE CYLINDER.