Crane boom having wear pads

Claim 1

In an extensible telescoping crane boom, a pair of telescopically interfitting boom sections each having side webs and a top and a bottom web, upper and lower load supporting wear pad assemblies respectively on the rear end and top of the interior boom section interposed between and being substantially parallel with the top webs of the two boom sections and on the forward end and bottom of the exterior boom section interposed between and being substantially parallel with the closely adjacent bottom webs of the two boom sections, upper and lower pairs of wear pads included in said upper and lower wear pad assemblies, the improvement comprising said lower wear pad assembly including a heavy retainer plate connected beneath the bottom web of the exterior boom section and having retaining recesses therein located directly below said side webs of the interior boom section, belleville springs having a small vertical height resting in the bottoms of said recesses, the wear pads of the lower pad resting on top of said belleville springs and extending upwardly through retaining apertures in the bottom web of the exterior boom section and engaging the bottom web of the interior boom section, said belleville springs operative to universally resiliently urge said wear pads of the lower pair into substantially complete seating engagement with the bottom web of the interior boom section, the wear pads of the upper and lower pairs being located directly above and below said side webs of the interior boom section for transmitting forces directly thereto, and the side webs functioning substantially as columns to absorb said forces.