Closed end-variable spring rate bushing

Claim 1

A YIELDABLE BUSHING ASSEMBLY COMPRISING A RIGID CIRCUMFERENTIALLY CONTINUOUS AXIALLY ELONGATED TUBULAR OUTER SLEEVE, A RIGID TUBULAR INNER SLEEVE WITHIN AND COAXIAL WITH SAID OUTER SLEEVE AND HAVING AN AXIAL LENGTH GREATER THAN THAT OF SAID OUTER SLEEVE, AND A TUBULAR ELASTIC RUBBER INSERT COMPRESSED BETWEEN SAID INNER AND OUTER SLEEVES AND EXTENDING AXIALLY BEYOND THE OPPOSITE ENDS OF SAID OUTER SLEEVE, SAID INSERT BEING UNDER RELATIVELY HIGH AXIAL ELONGATION AND RADIAL COMPRESSION AND HAVING OUTER END PORTIONS WITH A NORMAL CROSS-SECTIONAL AREA GREATER THAN THAT BETWEEN SAID SLEEVES WHICH OUTER END PORTIONS FILL THE SPACE BETWEEN SAID SLEEVES AT OPPOSITE ENDS OF SAID OUTER SLEEVE, SAID INSERT HAVING AN INTERMEDIATE PORTION BETWEEN INNER AND OUTER SAID END PORTIONS WITH A CROSS-SECTIONAL AREA LESS THAN THAT BETWEEN SAID SLEEVES, SAID INTERMEDIATE PORTION HAVING DIAMETRICALLY OPPOSED GROOVES BETWEEN SAID OUTER END PORTIONS WHICH EXTEND AXIALLY ABOUT 1/2 TO 2/3 THE LENGTH OF THE RUBBER INSERT.