Fig. 1685.
Referring to [Fig. 1685], bevel-wheel f is on the end of the cone spindle and drives bevel-wheel g, which drives spindle m. This spindle is provided with an automatic as well as a hand-feed motion, the construction being as follows:—
Referring first to the automatic feed, the cone pulley e′, [Fig. 1685], which is upon the main cone spindle of the machine, drives cone e, [Fig. 1683], and the latter operates a worm w, [Fig.1684], engaging a worm-wheel w, which drives the bevel gear a, shown by dotted circles in [Fig. 1685]; a drives the bevel gear c upon the sleeve o, which has journal bearing (in the frame a of the machine) both at its upper end and immediately above c. The upper end of the sleeve o is threaded to receive an inner sleeve n, within which is a spindle v, having journal bearing at each end of n and being fast to m, so as to revolve with it. End motion to n is prevented by a collar at its upper end r and by three steel washers at i, the latter taking the thread when the drill spindle m is in operation. The inner sleeve n is prevented from revolving by means of a lug or projection which passes into a slot or groove running vertically in the bore of the outer casing a; hence when o is revolved by a it acts as a nut to n, causing the latter to move endways and feed the drill spindle m.
To enable the engagement or disengagement of the automatic feed, there is at f, [Fig. 1684], a friction disk, the female half of which is fast upon the spindle that drives bevel gear a in [Fig. 1685], while the male half is in one piece with the hand wheel z, [Fig. 1684], which has journal bearing upon the spindle of a. g is a hand nut for engaging or disengaging the friction disks. In addition to the ordinary work table t, the knee u carries on a projection x a work-holding vice v, which is a great convenience, especially for cylindrical work. The base of the machine is provided with a plate upon which work may be secured independent of the work table t, or the lower end of a boring bar may be steadied by a step bolted to the base plate.
The construction of the machine, as will be seen, is very substantial throughout, since all the strains are central, the spindles are well supported, and there is a commendable absence of springs, pull-pins, and other light parts that are liable to get out of order from the wear and tear of the ordinary machine-shop tool. It may also be remarked that the combination of the two spindles is effected without impairing either the usefulness or handiness of the vertical spindle.
Fig. 1686.
In [Fig. 1686], which is taken from Mechanics, is illustrated a combined drilling and turning machine. In this machine the motion for both drilling and turning is received by belt on the cone pulley shown on the right, which is provided with back gear similar to that of a lathe. The live spindle thus driven has a face plate at the left-hand end, whereon work may be chucked to be operated upon by a tool in the compound slide rest shown on the cylindrical column. Motion to the drill spindle is conveyed by belt from a pulley on this same live spindle, hence the same cone pulley and back gear are utilized for either drilling or turning. The self-acting feed for the drill spindle is actuated by an eccentric on that spindle operating an arm, having a pawl engaging with the ratchet wheel on the lower end of the vertical feed spindle. Obviously when the pawl is thrown out of engagement with the ratchet wheel, the horizontal hand wheel may be used to feed the drill spindle by hand or to withdraw it, as the case may be.