Gas hydraulic spring for crushing apparatus

Claim 1

IN A CRUSHER OF THE GYRATORY TYPE HAVING A FRAME, A CRUSHING BOWL MOUNTED RIGIDLY TO SAID FRAME HAVING A DOWNWARDLY OPENING INNER CRUSHING SURFACE, AND A CRUSHING MANTLE THEREBELOW HAVING A GENERALLY VERTICAL MAINSHAFT JOURNALED IN SAID FRAME ABOVE AND BELOW SAID MANTLE AND AN UPWARDLY FACING OUTER CRUSHING SURFACE OPERATIVELY SPACED FROM SAID BOWL SURFACE AND ADAPTED TO CRUSH MATERIAL THEREAGAINST BY GYRATORY MOVEMENT OF THE LOWER JOURNAL OF SAID SHAFT, THE SPACING BETWEEN SAID SURFACES BEING ADJUSTABLE BY VERTICAL MOVEMENT OF SAID MANTLE AND SHAFT RELATIVE TO SAID BOWL AND FRAME, THE COMBINATION THEREWITH OF SELF-CONTAINED GAS HYDRAULIC MEANS BOTH TO ADJUST THE SPACING BETWEEN SURFACES AND TO MAINTAIN A PREDETERMINED SPACING THEREBETWEEN UP TO A PREDETERMINED LOAD THEREBETWEEN AND TO ACCOMMODATE AN OVERLOAD BY RESILIENTLY INCREASING SAID SPACING, SAID MEANS INCLUDING AT LEAST ONE PISTON HOUSING HAVING CLOSED OPPOSITE ENDS, A MAIN PISTON IN SAID HOUSING SLIDABLE BETWEEN SAID ENDS, AND A GASEOUS FLUID UNDER PRESSURE BETWEEN SAID PISTON AND ONE OF SAID CLOSED ENDS OF SAID HOUSING, SAID MEANS BEING OPERATIVELY ASSOCIATED WITH SAID FRAME AND SHAFT SO THAT THRUST BETWEEN SAID CRUSHING SURFACES IS COMMUNICATED TO SAID HOUSING AND PISTON AGAINST THE PRESSURE OF SAID FLUID, SAID PRESSURE BEING SUCH THAT THE TOTAL FORCE EXERTED THEREBY IS SUFFICIENT TO MAINTAIN SAID PREDETERMINED SPACING BETWEEN SAID BOWL AND MANTLE AS LONG AS THE CRUSHING LOAD THEREBETWEEN DOES NOT EXCEED SAID PREDETERMINED LOAD, SAID MEANS BEING REMOVABLE FROM SAID CRUSHER WITHOUT NEED FIRST TO DISCHARGE ANY OF SAID FLUID THEREFROM, AND MEANS FOR ADJUSTING THE SPACING BETWEEN SAID BOWL AND MANTLE, SAID ADJUSTING MEANS BEING EFFECTIVE INDEPENDENTLY OF SAID FLUID IN SAID HOUSING.