Hydraulic-elastomeric mount

Claim 1

In a hydraulic-elastomeric vehicle engine mount having a pair of rigid mounting members, a hollow elastomeric body operatively connecting the members, an elastomeric diaphragm cooperating with the body to form a closed cavity that is substantially filled with a liquid, a rigid partition dividing the cavity into a chamber enclosed by the body and a chamber enclosed by the diaphragm, an elongated damping orifice having a length substantially greater than its width dimension connecting the chambers so as to provide hydraulic damping as one mounting member is forced to vibrate relative to the other in opposite directions at varying amplitudes and frequencies, a singular rigid damping decoupler mounted for free limited reciprocal movement on the partition so as to effect cyclic volume change in one and then immediately the other of the chambers and thereby permit vibratory amplitudes below a prescribed level and frequency without forcing liquid through the orifice and thus without hydraulic damping, the improvement comprising a secondary orifice through said partition for connecting said chambers, and singular rigid jounce-rebound control valve means solely on and movable with said decoupler for essentially immediately closing said secondary orifice to prevent flow therethrough between said chambers on pressure buildup in one of said chambers and essentially immediately opening same to permit flow therethrough between said chambers on pressure buildup in the other chamber so as to essentially immediately effect a reduction in the hydraulic damping normally provided by said damping decoupler in one of said force directions as compared with that in the other force direction during the damping decoupler operation.