Patent ID: 7959174

Claim:
A suspension system for a vehicle having a rear axle, comprising: a plurality of spring assemblies, each spring assembly of the plurality of spring assemblies being comprised of, in combination, a coil spring having top and bottom ends and an air spring having top and bottom ends, the coil spring and the air spring arranged end-to-end in series around a common central axis such that the top end of either the coil spring or the air spring is attached to the bottom end of either the air spring or the coil spring, wherein the bottom end of either the coil spring or the air spring is attached to the rear axle of the vehicle and the top end of either the air spring or the coil spring is attached to the vehicle; and attachment means for joining the coil spring end-to-end with the air spring of respective spring assemblies, and rear axle mounting means for one of (a) retaining the coil spring of respective spring assemblies in substantial alignment with the central axis and mounting the coil spring of respective spring assemblies above the rear axle or (b) mounting the air spring above the rear axle; wherein the air spring comprises an inflatable section, top and bottom structural plates positioned at opposite ends of the inflatable section in opposition to one another and having a plurality of holes provided therein, and an air fitting for inflation and deflation, and wherein the attachment means comprises an attachment plate assembly positioned between the coil spring and the air spring of respective spring assemblies for joining the coil spring end-to-end with the air spring; wherein the attachment plate assembly comprises an attachment plate to which one said structural plate of the air spring is attached and to which the coil spring is attached; further comprising a coil spring retainer positioned between the attachment plate and the coil spring of respective spring assemblies for attaching the coil spring to the attachment plate, wherein the coil spring retainer is fixedly connected to the attachment plate, and wherein the coil spring retainer engages the coil spring and urges the coil spring against the attachment plate so that the coil spring and the air spring of respective spring assemblies are joined end-to-end, wherein the coil spring retainer has a profile which engages the coil spring, and wherein the coil spring retainer is fixedly connected to the attachment plate by at least one connection means so that the coil spring retainer urges the coil spring against the attachment plate.