The segments are held to the disc by the two sets of screws, r, s, and are further secured at their edges by pieces of copper, as shown at w. Between the edges of the segments there is left a space or opening of about 1⁄16 inch, which is necessary to insure that the segments shall not bind together edgeways, as that might prevent their seating fairly against the face of the disc d.
The seats for these pieces of copper are shaped as shown in the face views at w, and in the edge views at w′, the mouth of the slot being widened on each side, so that riveting up the pieces of copper will prevent the segments from moving sideways.
In fitting in these pieces of copper, it is essential to take care that they do not completely fill the slots, but leave a small opening at each end of the slot, as at f and g in the figure, and in order to do this the copper must be left about 1⁄8 inch narrower than the width of the slot.
If the copper is, in riveting up, brought to bear against the end of the slot, it will twist the segments out of line one with the other, causing the saw to drag, cut roughly and produce bad work.
Left-Hand. Right-Hand.
Fig. 3107. Fig. 3108.
[Figs. 3107] and [3108] represent portions of segmental saws for cutting veneering. In some of these saws the screw holes are so arranged that the segments can be moved out to maintain the diameter of the saw as it wears.