This section is from the book "Lathe Design, Construction And Operation, With Practical Examples Of The Lathe Work", by Oscar E. Perrigo. Also available from Amazon: Lathe Design: Construction And Operation.
Definition of the word engine. What is meant by an engine lathe. The plan of this chapter. The Reed lathes. Reed 18-inch engine lathe The Pratt & Whitney lathes. Their 14-inch engine lathe. Flather lathes. Flather 18-inch quick change gear lathe. Prentice Brothers' Company and their 16-inch engine lathe. The Blaisdell 18-inch swing engine lathe. The New Haven 21-inch engine lathe. Two lathe patents by the author. The Hendey-Norton lathes. Who were the pioneers in quick change gear devices? The Hendey-Norton 24-inch engine lathe. The Lodge & Shipley 20-inch engine lathe.
A large majority of the lathes in use in the machine shop or manufacturing plant are what have been known for years as engine lathes. Just why this qualifying designation of engine was applied to them is not clear, although we know that in former times the term engine was applied to many machines, particularly those of the higher class, and very early in the development of the mechanic arts the word seems to have been used to designate almost any kind of a machine. Thus we read in the Marquis of Worcester's "Century of Inventions," published in 1683, of "an engine that may be carried in one's pocket" for blowing up ships; "a portable engine in the way of a tobacco tongs"; "an engine whereby one man may take out of the water a ship of 500 ton," and so on, showing the strange uses to which the term engine has been put in times past, while at a comparatively recent period an indexing machine was called a dividing engine, while Webster says broadly that an engine is "a machine in which the mechanical powers are combined."
Recurring to the subject, by the term of engine lathe we mean that class or type of lathes which is usually so denominated mechanically and commercially, and which may be defined as a metal turning lathe, having a back geared head-stock; a tail-stock capable of being set over for turning tapers; a carriage provided with suitable tool-supporting mechanism and having connected with it an apron carrying the necessary gearing mechanism for producing power lateral and transverse cutting feeds; and a lead screw, with suitable gearing for driving it, whereby the usual screw threads may be cut, through its proper connection with the apron mechanism.
With this conception of the design, construction, and office of the engine lathe of the present day, the following examples are presented and their special features discussed, with a view to the better understanding of this important machine tool. The engravings, the facts stated, and the dimensions, where the same are given, are derived from the machines themselves or their builders, or both, and the aim is to make the information as correct and the estimate of their practical utility as fair as is possible, so that what is here set down will be of value to the buyer of these machines; to the machinist who uses them; to the draftsman and designer who may desire to know of their individual peculiarities; and to the student who would learn valuable lessons in relation to the design and development of the Modern American Lathe.
While it is not expected or intended that the lathes of all makers shall appear in this connection, those of the more prominent builders will be introduced, and to these will be added such others as may possess particularly commendable or novel features, in order that the essential points of the engine lathe may be well and thoroughly illustrated and described, with a minuteness that their importance may demand.
Among the many manufacturers of lathes the F. E. Reed Company may deservedly receive the title of "ancient and honorable," not because the product of the concern deserves the name of ancient, but because of the long and honorable career of the establishment which has always stood for good materials, good workmanship, and practical design for every-day tools capable of standing up to the work, year in and year out, with whatever the machine tool market affords. While the company have always built substantial and practical tools, of ample strength and many conveniencies for the operator, they have not been given to the exploiting of mechanical fads and fancies or to going to extremes in any one direction.
As an example of the engine lathe built by this company, the 18-inch swing engine lathe shown in Fig. 223 is given. It will be seen that here is a deep and strong bed supported upon the older form of legs instead of cabinets. Upon the front leg is a special cabinet for holding the change-gears which are of the older form of change-gears proper, that is, removable. The feed is by means of a belt upon the well-known three-step cone, with which is arranged a change of gears making six feeds.
Fig. 223. - 18-inch Swing Engine Lathe built by the F. E. Reed Company.
Fig. 224. - Spindle Box of the Reed Lathe Ready for Babbitting.
Fig. 225. - Spindle Box of the Reed Lathe after Babbitting.
The head-stock is heavy and strong and carries a spindle made from a crucible steel forging which runs in cast iron boxes lined with genuine babbitt metal, as shown in Figs. 224 and 225.
In the first of these illustrations is shown the cast iron box properly milled out to fit the housings of the head-stock. After this operation it is bored out and then slotted ready to receive the babbitt metal lining. It will be noticed that these are all "dovetail" slots, the object of this form being to hold the lining metal securely in its place. The babbitt metal is cast into the box, after which it is compressed sufficiently to fill out any shrinkage that may have occurred upon cooling, and to render it more dense and durable. It is then re-bored, reamed, and hand scraped, so as to fit the spindle as perfectly as possible. Constructed in this manner there is nothing coming in contact with the spindle except the babbitt metal, which, when finished, has the appearance shown in Fig. 225.