« НазадПродовжити »
only one lathe can be purchased this should preferably be of this type. The gap in the lathe bed makes it possible to swing much larger work than would be possible in either of the forms shown at A or B, and a well designed gap bed will not be appreciably weaker than the solid bed form. All ordinary work may be handled on a lathe of this form, and in addition, the out-of-theordinary jobs, such as machining a flywheel, facing a large clutch cone or plate, etc., can be accomplished when desired.
A complete outfit suitable for most of the requirements of garages and general repair shops, which sells for approximately
Fig. 27.-Typical Screw Cutting Engine Lathe with Complete Equipment
Adapted for Automobile Repair Work.
$200, is shown at Fig. 27. This includes a 13-inch swing x 51/2-foot bed, back-geared, screw-cutting engine lathe. It is provided with automatic longitudinal and cross feeds. The cone pulley has four steps for a two inch belt. The ratio on the back gearing is 7 to 1. The tail stock is cut away to permit the compound rest to be swung around to 90 degrees, and is fitted with a sleeve, bored to conform to Morse taper No. 4, and has a self-discharging center. The tail stock may be set over for taper turning. The cross feed screw has a graduated collar so the feed may be regulated to one-thousandth of an inch. Change speed gears are furnished to cut threads from 5 to 36, including 11/2 pipe thread and one extra compound gear to cover all special threads from 3 to 72. The special garage equipment consists of the parts outlined in illustrations. These are large and small face plates, follow rests, steady rest, compound rest, centers, wrenches, full set of change speed gears, double friction countershaft, four jaw independent chuck, drill
chuck, set of lathe dogs, and a set of turning and boring tools. An equipment of this nature is not only practical, but if the complete outfit is purchased the garage man is sure of obtaining a practical machine tool for all ordinary repair work. The outfit shown would be the same regardless of the size of lathe purchased, except that the auxiliaries, such as face plates, chucks, and tools, would be all properly proportioned for the machines they were to be used with. In purchasing a number of lathes it is not necessary to buy a full equipment for each lathe. For instance, two chucks
and two face plates would be enough for four lathes if these were of the same size. The follow rest and steady rest, which are not used continually and forming the part of one lathe outfit, would, of course, be suitable for any others of the same pattern. The various types of lathe tools, chucks, etc., will be considered more at length in the next chapter, which deals with the small tool equipment of the shop.
A lathe is not complete without a number of additional con
veniences, such as shown at Figs. 28 and 29. The importance of proper illumination of the work is apparent, and this may be assured by using a universally jointed incandescent lamp support such as shown at Fig. 28. The universal joints make it possible to set the lamp at any desired angle and at any point that is most convenient for the operator within a wide range. When cutting resisting materials, such as the alloy steels used so widely in automobile construction, as well as when taking roughing cuts, the lubricant container shown at Fig. 29, A, is of value, as it not only is capable of ready attachment to the lathe carriage, but will direct a constant stream of lubricants or cutting compound on the point of the tool in order to prevent it from becoming overheated. As the container is supported by the carriage, it must move in proper relation with the cutting tool. The rack shown at B is an important adjunct, inasmuch as it provides a place for holding the machinist's tools where they will be accessible and yet out of the way. The base of the rack is designed to fit the lathe shears, and will keep various wrenches, files, etc., out of contact with the lathe ways. A drawer is provided, which may be locked, in which the machinist can keep his finer tools, such as the micrometers, calipers, etc. Another adjunct to the lathe is the tray mounted on a wheeled stand shown at C, designed to be placed under the lathe bed to catch chips and borings of metal and keep these from the floor. Its construction is very simple, and as it is made entirely of metal, it is durable and fire-proof. The various articles of equipment outlined are marketed by the New Britain Machine Company.
Shapers, Planers, and Drilling Machinery.–Both the shaper and planer remove metal from flat surfaces, whereas the lathe is essentially a tool for machining cylindrical surfaces. In the shaper, which is shown at Fig. 30, A, the work is mounted in a fixed work-holding vise, while the cutting tool is carried in a tool post mounted at one end of the reciprocating shaper head. The work may be moved laterally by hand or power feed, while the tool may be raised or lowered to get the depth of cut by the lever C. The tool post is mounted on an index so that it may be set at any desired angle. As previously stated, much of the work that can