is one hundred thousand pounds and it weighs 870 pounds. It is a very convenient press for use in the automobile repair shop and its construction makes it specially well adapted for pressing shafts into and from pulleys, flywheels, gearhubs, etc., and also for straightening automobile shafts. The engraving shows the con

struction and principle of operation of the machine very distinctly. Two large guide screws rise from the table upon which the cross head is adjustably supported, as it has two semi-screw nuts and toggle mechanism by which the cross head is held fast or released. for vertical adjustment. The cross head is balanced by weights, as shown, and a steadying bar connects the press cup with the press screw. A spur-toothed ratchet wheel is fixed on one end of the

press screw, this being embraced by a forked lever head fulcrumed to oscillate on the press screw. A double acting spring pawl engages the teeth of the ratchet, and a hand crank is attached to the press screw in order that it may be raised or lowered quickly, if desired. After the object has been placed in the press, the cross head in which the central screw is mounted can be instantly dropped to the work, and with a few turns of the screw the required pres

sure may be applied. An important saving in time is thus effected, compared with the method where a number of blocks must be placed on the bed plate to raise the object sufficiently to be acted on by the press screw. Tapering squared sockets are provided in each end of the pawl carrier to permit the introduction of the long bars, shown leaning against the press base, which will provide a very great leverage on the screw. The small arbor press shown at C, is of the Greenerd type and is intended to be placed on the lathe

shears where it will be handy to the operator. Such a press is very useful for small work.

For straightening shafts a special form of press is provided which is superior for that work as it is designed for it. A typical shaft straightener is shown at Fig. 33, B. As will be noticed, it is very similar in construction to an arbor press, except that the base is provided with a slot in which V-blocks are placed to support the shaft. Another V-block is attached to the end of the screw and

bears upon the shaft. In order to ascertain if the shaft is properly straightened, a pair of centers are mounted in front of the press on a long bar attached to its base. As a shaft must be placed on centers a number of times in straightening in order to observe the progress of the work, the combination shown is evidently superior for the purpose. With the usual form of arbor press the shaft must be taken to a lathe and swung between the centers after each pressing operation. The process of shaft straightening is a comparatively simple one, as it is revolved on centers and the high spot indicated. by holding a piece of chalk against the shaft surface. The high spot is then placed directly under the press screw and the pressure brought to bear against the shaft will tend to straighten it, owing to its two point support.

Another very good form of press for repair shop use is shown at

Fig. 34. At A, the method of removing gears from a shaft is shown, while at B, the press is depicted straightening a shaft. The press is easily handled, as a small hand wheel is provided on the front of the machine to run the ram quickly up or down. This press has a 36 inch space between uprights, a 12 inch opening under the plate, 26 inch over the plate and 48 inch over the lower plate or table. Being mounted on wheels the press can be easily moved to any portion of the shop to straighten an axle or over a trap hole through which a crank shaft may be placed to remove a flywheel. The auxiliary plate at the bottom of the chamber under the revolving plate has a revolving centre and is very convenient when needed. The centre of this plate is provided with a self-centering surface or a spherical or ball joint which will insure steady pressure on the centre line of the press even if the work is tilted slightly when it is initially placed. With this press one man can exert a pressure of ten tons and two men sixteen tons. With the leverage form, the workman is able to "feel" what he is doing, therefore the danger of applying excessive pressure is avoided.

Special Tool Attachments of Value.-Many special devices can be used to facilitate machine work which should be included in the equipment. In automobile repair work many irregular pieces are handled, and it would seem to the writer that a set of universal angle plates, which could be used with equal facility on the bed of the drill press or shaper or on the face plate of the lathe, would be an excellent investment. Then there are the index heads, which can be mounted on almost any machine tool, and which enable one to cut gear teeth, mill slots, or drill holes at regular intervals around the periphery of a circular piece, without time spent in laying out. The vises for holding work on the drill press or shaper should be a pattern that they can use on the face plate of the lathe, and two or three different sizes can be employed to advantage. Special boring bars, cutters, and grinding wheels should be provided, as needed. A small portable electric motor as shown in Fig. 35 mounted on the lathe tool rest can be used in grinding, both internal and external. For the sharpening of drills, cutting tools, reamers, etc., small universal bench grinders as at A, Fig. 36, driven directly by small electric motor

or by belt from the line shafting, ena be profitably installed. The equipment of drills, taps, reamers, etc., will depend entirely upon the capital one wishes to invest in special epuipment, but endeavor should be made to have an assortment that will include most of the standard sizes employed in making automobile parts. These are fully considered in the following chapter.