Bracket No. VI.
Fig. 113.
The Tube Fitting.
Fig. 114.
The Shafts and Tube-fittings.—The stud sockets will not provide for every case in which wheels have to be mounted and driven. We must often employ shafts (see for instance [Figs. 30], [47], [101]). The shafts we use are turned iron rods ¾" in diameter, and of various lengths from 6" up to 4'. To support the shafts we use for bearings the tube fitting ([Fig. 114]). This is a brass casting which consists of a tube M N 2" long, and 1¼" in external diameter, bored ¾" so as to fit the shaft. The back of this tube is a flat surface parallel to the bore, and from it projects a screw ⅝" diameter, and 1⅝" long with a nut which is however omitted in the drawing. This screw may be of the same size as that of the studs, and it is intended for the same purpose, namely to attach the bearing to the hole in a bracket. The tube may of course be fixed at any desired angle in the plane parallel to the face of the bracket. To prevent the endlong motion of the shaft cast iron or brass rings are employed ([Fig. 115]). These are bored ¾", and furnished with a binding screw by which they may be tightened on the shaft in any position. To avoid injury to the shaft it is well to have a narrow flat surface filed along it to receive the end of the binding screw. The use of the rings is shown in [Fig. 47]. If as often happens ([see for example Fig. 102]) a barrel has to be set in motion by a shaft the required attachment can be made by simply slipping on the barrel, and then putting at each end of it two of the pinned rings ([Fig. 115]). The pins enter holes bored into the barrel for their reception so that when the rings are bound to the shaft by their screws the barrel must revolve with the shaft.
The Pinned Ring.