Fig. 626.
[Fig. 625] represents a form of bed in which the fit adjustment is also made at the front end only of the bed, and there is a flange or slip at a, which receives the thrust outwards of the carriage; and a similar design, but with a bevelled edge, is shown in [Fig. 626].
Fig. 627.
In [Fig. 627] is shown a lathe shear with parallel edges, the fit being adjusted by a single gib d, set up by set-screws s. In this case the carriage will fall or move endwise, to an amount equal to whatever the amount of the wear may be, and no more, but it may be observed that in all the forms that admit of wear endways (that is to say in the direction of b in [Fig. 621]), the straightness of the shears is impaired in proportion as its edges are more worn at one part than at another.
Fig. 628.