Vibration absorption mounting for a rooftop air handling unit

Claim 1

An improved pre-assembled vibration absorption system for a rooftop mounted air handling unit comprising, in combination, a rectangular shaped upper curb adapted to have in attached relation thereto said air handling unit, plural bolts each bolted to extend in depending relation from said upper curb at selected locations therealong, a rectangular shaped lower curb adapted to be mounted on said rooftop in supporting relation beneath said upper curb, and at each location of one said depending bolt an inverted U-shaped housing attached to said lower curb bounding a compartment for a spring and having an opening in the top thereof through which said depending bolt has an operative position projected into said compartment, a first nut threadably engaged to said bolt in said compartment adjacent the underside of said top of said housing having an initial operative position bolting said housing to said upper curb such that said upper and lower curbs are correspondingly bolted to each other to facilitate the transit thereof to a rooftop site, a compressible helical spring disposed in each said compartment in surrounding relation about a cooperating depending bolt, and a second nut positioned beneath said first nut and downwardly adjustable along said bolt so as to cause compression of said spring and a corresponding increase in the upward force urgency therein, whereby following the unbolting of said upper and lower curbs from each other by the threadable adjustment of each said first nut the threadable adjustment of each said second nut down along said bolt causes compression of said helical spring and a force urgency therein effective to lift said upper curb into a spaced clearance position above said lower curb, to thereby permit vibrating movement of said upper curb relative to a stationarily mounted lower curb.