Adjuster for track-mounting assembly

In combination with a substrate to which a mounting plate fixed to a longitudinally extending rail is secured by a plurality of bolts anchored in the substrate, each bolt having a cylindrical shank extending through the mounting plate and a head bearing downward on the mounting plate, the rail plate being formed at each bolt with an array of transversely uniformly spaced and upwardly projecting ridges, respective adjusters at each of the bolts and each comprising:

• an adjuster plate formed with a vertically throughgoing transversely elongated slot through which the respective bolt extends and having a lower face formed with an array of downwardly projecting and transversely spaced ridges generally complementary to the ridges of the mounting plate and matable therewith and an upper face formed with a central recessed seat defined between two longitudinally extending and parallel edges at a predetermined transverse spacing;
• and
• a gauge plate formed with a first pair parallel outer edges spaced apart by a distance substantially equal to the transverse spacing of the seat edges and with a central circular hole of a diameter substantially equal to an outer diameter of the shank of the respective bolt that extends vertically through the circular hole, the gauge plate being fitted in the seat with its outer edges engaging the seat edges and the circular hole vertically aligned with the slot of the adjuster plate, the circular central hole being offset centered on an axis offset from a midpoint equispaced between the outer edges of the first pair by a first offset equal to a fraction of a transverse ridge-to-ridge spacing of the arrays of ridges.