US Patent 7507499 Battery pack arrangements

Battery packs are retained by frames which are comprised of plastic beams and aluminum corner connectors that peripherally surround the battery packs. The plastic beams are tensioned by tensioning bolts which pass through the aluminum corner connectors and thread into threaded pin inserts laterally seated in the beams. As the tensioning bolts are advanced into the inserts the beams are axially tensioned. Damping pads are disposed between the separate battery modules of the battery packs, as well as at the corners of the frames, to both absorb vibrational and spike impacts. The damping pads frictionally engage the outer surfaces of the battery cases so that the batteries will not move in the Z-axis direction.