Fig. 499.
The V grooves q and q′ fit upon the inner raised Vs shown at v, v′ in [Fig. 499].
Fig. 500.
[Fig. 499] is a side view of the slide rest for holding and traversing the cutting tool. a represents the carriage resting upon the raised Vs marked v′′ and v′′′ and prevented from lifting by its own weight, and in front also by the gib a secured to a by the bolt b and having contact at c with the shears. a carries at d a pivot for the cross slide b and at e a ball pivot for the cross slide elevating screw c. This screw is threaded through the end of b so that by operating it that end of b may be raised or lowered to adjust the height of the cutting tool point to suit the work. To steady b there is provided (in addition to the pivots at d) on a two lugs f, between the vertical surfaces of which b is a close working fit. The upper surface of b is provided with a V-slide-way g, to which is fitted the tool rest d (the construction being more clearly shown in [Fig. 500]).
The means for traversing d along the slide g on b is as follows:—
A nut i is secured to d by the screw bolt j, and threaded through the nut i is the cross-feed screw e, which has journal bearing in the piece k, which is screwed into the end face of b; there is a collar on e which meets the inner end of k, and the handle f being secured by nut to that end of e its radial face forms a shoulder at m which with the collar prevents any end motion of e, so that when f is rotated e rotates and winds through the nut i which moves d along b.
An end view of a, b, and d is shown in [Fig. 500], in which the letters of reference correspond to those in [Fig. 499]. b′ and b′′ are the projections that pass into a and receive the pivoting screws d and d. To adjust the fit and take up any wear that may ensue on the slide g, on b and on the corresponding surface on d, the piece n is provided, being set up by the adjusting screws o.
To adjust the fit and take up the wear at the pivots d they are made slightly taper, fitting into correspondingly taper holes in b.