A plan view of one-half of the head is shown in [Fig. 1889], the edge of j being graduated for a guide in elevating the head at an angle, at v is the bevel-gear for driving k, and at s is a pinion receiving motion from the change gears.

[Large
image
(63 kB).]

Fig. 1890.

Fig. 1891.

The feed motions for the traversing table (f, [Fig. 1880]) is shown in [Figs. 1889], [1890], and [1891], g represents the universal joint rotating continuously the spindle a, which provides journal bearing to bevel pinion b and the clutch c, these two being fixed together; d is a clutch which rotates with a, but is capable of a certain amount of end motion on or along a to enable it to engage or disengage with its mate c. When d engages with c the rotary motion of a is transmitted through d, c, b, to f, which actuates the feed screw a, while when d is disengaged from c, it rotates, leaving c b f idle. d is operated to engage with or disengage from c, its hub is enveloped by the fork e, which is attached to rod h, which is provided with a recess to receive one end of the bell crank l, the other end of which lies in a recess in the rod m, to the end of which is connected the lever handle n, which is pivoted at o; hence operating n laterally as denoted by the arrows, throws d in or out of gear with c, according to the direction of motion, direction p being that to throw it out of, and q to throw it into gear or engagement. At r is a stop that can be fixed at any adjusted position or desired location along the bed upon which the feed table or carriage (f, [Fig. 1880]) slides, so that when that carriage is being self-actuated it will traverse until the inner end of n meets the stop, whereupon the stop will move n and thereby disengage d from c, causing the automatic feed to cease. All that is necessary, therefore, is to set r in such a position along the bed that it will operate n when the milling cutter has operated to the required distance along or over the work; s is the stud arm that carries wheel t to engage with and drive the pinions shown in [Fig. 1889], and u is the stud for carrying the wheels for giving the required changes of rotation to k, [Fig. 1889], the wheels on u receiving motion from a gear placed at the seat v on the feed screw a. The stud arm s being slotted, can be moved forward, transmitting motion from the change wheels on u to wheel s, [Fig. 1890], causing the automatic spiral feed to actuate; or by moving s outwards, this feed is thrown out of action, and either the hand feed of handle w or the self-acting feed traverse may be employed.

Thus the hand, and all the automatic feed motions are driven from the feed screw a, and each of the automatic feed motions may be started or stopped by operating the lever n, while the stop r causes each of them to cease when the work has traversed to the required distance beneath the milling cutter.