Tandem spring suspensions

Claim 1

IN A TANDEM SPRING SUSPENSION FOR A VEHICLE HAVING TANDEM AXLES: A PAIR OF ELONGATED SPRING MEANS HAVING SPACED OUTER ENDS AND ADJACENT INNER ENDS; AN EQUALIZER HAVING SPACED FORE AND AFT PARTS ENGAGEABLE RESPECTIVELY BY THE INNER ENDS OF THE SPRING MEANS AND HAVING AN OPENING AT ITS MEDIAL SECTION; A SUPPORT FOR THE EQUALIZER COAXIAL WITH THE OPENING THEREOF ENABLING THE EQUALIZER TO PIVOT ABOUT SAID SUPPROT AS THE RESULT OF A FORCE IMPRESSED ON THE EQUALIZER BY AN INNER END OF ONE OF THE SPRING MEANS; AND A COMPOUND BUSHING INTERPOSED BETWEEN SAID SUPPORT AND THE OPENING OF SAID EQUALIZER; SAID BUSHING CONSISTING ESSENTIALLY OF (1) A CENTER SLEEVE OF RIGID MATERIAL, (2) AN INNER BEARING OF RESILIENT MATERIAL FIRMLY SECURED TO THE INNER SURFACE OF SAID SLEEVE, AND (3) AN OUTER BEARING OF RESILIENT MATERIAL FIRMLY SECURED TO THE OUTER SURFACE OF SAID SLEEVE, SAID INNER BEARING ENGAGING SAID SUPPORT WITH A FRICTIONAL FORCE AND SAID OUTER BEARING ENGAGING SAID MEDIAL SECTION OF THE EQUALIZER WITH A DIFFERENT FRICTIONAL FORCE, WHEREBY AT SMALL ANGLES OF EQUALIZER TILT THE BEARINGS MERELY TWIST WHILE AT PREDETERMINED LARGE ANGLES OF EQUALIZER TILT THE BUSHING AS A SHOLE SLIPS ON SAID SUPPORT, OVERCOMING FRICTIONAL RESISTANCE BETWEEN THE INNER BEARING AND SAID SUPPORT.