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Fig. 501.

The dotted circle t′, represents a pinion fast upon the cross-feed screw (e, [Fig. 499]); the similar circles t and s′′ also represent pinions, the three composing a part of the method of providing an automatic or self-acting cross feed or cross traverse to d by rotating it through a gear-wheel motion derived from the rotation of the independent feed spindle, as is described with reference to [Fig. 501].

m in [Fig. 500] represents a cavity or pocket to receive wool, cotton or other elastic or fibrous material to be saturated with oil and thus lubricate the raised Vs while keeping dirt from passing between the rest and the Vs. The shape of these pockets is such as to enable them to hold the cotton with a slight degree of pressure against the slides, thus insuring contact between them.

The mechanical devices for giving to the carriage a self-acting traverse in either direction along the bed, so as to feed the tool automatically to its cut, and for giving to the tool rest (d, [Fig. 499]) traverse motion so as to feed the tool to or from the line of centres along the cross slide, are shown in [Fig. 501], which presents two views of the feed table or apron. The lower view supposes the feed table to be detached from the carriage and turned around so as to present a side elevation of the mechanism. The upper view is a plan of the same with two pinions (n and n′), omitted. a represents the part of the lathe carriage shown at a in [Fig. 500]. It has two bolts p and p′, which secure the apron g, [Fig. 501], to a. At h is the independent feed spindle or feed rod operated by belt from the cone pulley r, [Fig. 494], or by a gear on stud p at v. h is carried in bearings fixed to each end of the lathe shears or bed, both of these bearings being seen in [Fig. 492]. h is also provided with a bearing fixed on the feed apron as seen in [Fig. 501], and is splined as shown at h. At i is a bracket fast upon the apron g and affording journal bearing to j, which is a bevel pinion having a hub which has journal bearing in the bracket i. The fit of the bearing to the journal is here again adjusted by a split in the bearing with a screw passing through the split and threaded in the lower half (similar to the construction of d in [Fig. 493]); j is bored to receive h, and is driven by means of a feather projecting into the spline h. When therefore, the carriage a is moved it carries with it the apron g, and this carries the bracket i holding the bevel pinion j, which is in gear with the bevel-wheel k, and therefore operates it when h has rotary motion. At the back of k, and in one piece with it, is a pinion k′, both being carried upon the stud l; pivoted upon this same stud is a plate lever m, carrying two pinions n and n′ in gear together, but n only is in gear with k′, hence k′ drives n and n drives n′. Now in the position shown neither n or n′ is in gear with the gear-wheel o, but either of them may be placed in gear with it by means of the following construction:—

At the upper end of m there is provided a handle stud m′ passing through the slot m′′ in g. Screwing up this stud locks m fast by binding it against the surface of g. Suppose, then, m′ to be unscrewed, then if it be moved to the right in the slot m′′, n will be brought into gear with o and the motion will be transmitted in the direction of the arrows, and screwing up n would retain the gear in that position. But suppose that instead of moving m′ to the right it be moved to the left, then n′ will be brought into gear with o and the direction of rotation of o will be reversed.

Thus, then, o may be made to remain stationary or to rotate in either direction according to the position of m′ in the slot m′′, and this position may be regulated at will.

The gear o contains in its radial face a conical recess, and upon the same stud or pin (p) upon which o is pivoted, there is fixed the disk p′, which is in one piece with the pinion p′′; the edge of p′ is coned to fit the recess in the wheel o, so that if the stud p is operated to force the disk p′ into the coned recess in o the motion of wheel o will be communicated to disk p′, by reason of the friction between their two coned surfaces. Or if p be operated to force the coned edge of the disk out of contact with the coned bore or recess in gear o, then o will rotate while p′ and p′′ will remain stationary. Suppose the coned surfaces to be brought (by operating x) into contact and p′ to rotate with o, then p′′ being in gear with wheel q will cause it to rotate. Now q is fast to the pinion q′, hence it will also rotate, and being in contact with the rack which is fixed along the shears of the lathe and a section of which is shown in the cut, the whole feed table or apron will be made to traverse along the lathe shears.