Fig. 175.
Another method of securing the teeth in the mortises is to dovetail them at the small end and drive wedges between them, as shown in [Fig. 175], in which c c are two contiguous teeth, r the wheel rim and w w two of the wedges. On account of the dovetailing the wedges exert a pressure pressing the teeth into the mortises. This plan is preferable to that shown in the [Fig. 174] inasmuch as from the small bearing area of the pins they become loose quicker, and furthermore there is more elasticity to take up the wear in the case of the wedges.
Fig. 176.
Fig. 177.