59, A. As will be observed, the chuck spindle is driven by a small bevel pinion, which in turn, is operated by a large bevel gear turned by a crank. The gear ratio is such that one turn of the handle will turn the chuck five or six revolutions. A drill of this design is not suited for drills any larger than one-quarter inch. For use with drills ranging from one-eighth to three-eighths, or even half

inch the hand drill presses shown at C and D are used. These have a pad at the upper end by which pressure may be exerted with the chest in order to feed the drill into the work, and for this reason they are termed "breast drills." The form at C, has compound gearing, the drill chuck being driven by the usual form of bevel pinion in mesh with a larger bevel gear at one end of a countershaft. A small helical spur pinion at the other end of this countershaft receives its motion from a larger gear turned by the hand crank. This arrangement of gearing permits of high spindle speed without the use of large gears, as would be necessary if but two were used. The form at D, gives two speeds, one for use with small drills is obtained by engaging the lower bevel pinion with the chuck spindle and driving it by the large ring gear. The slow speed is obtained by shifting the clutch so that the top bevel pinion drives the drill chuck. As this meshes with a gear but slightly larger in diameter, a slow speed of the drill chuck is possible. Breast drills are provided with a handle screwed into the side of the frame, these are used to steady the drill press. For drilling extremely large holes which are beyond the capacity of the usual form of drill press the ratchet form shown at B, may be used or the bit brace outlined at E. The drills used with either of these have square shanks, whereas those used in the drill presses have round shanks. The bit brace is also used widely in wood work and the form shown is provided with a ratchet by which the bit chuck may be turned through only a portion of a revolution in either direction if desired.

One of the most difficult things to do in connection with installing accessories such as tire irons, license hangers, special lamp brackets, trunk racks, etc., is drilling holes in the pressed steel frame of the chassis, as the special alloy steel used for this purpose at the present time requires considerable exertion if one attempts to bore the hole with an ordinary breast drill. Electrically operated drills have a great advantage when used in making small holes but when they have sufficient capacity to take drills over 1/2inch in diameter they are bulky to handle. These are of obvious utility when electrical current is available, but all shops are not so provided and many workmen do not like to use them because

of danger of shocks through short circuiting, or the liability of getting out of order, or of injuring the operator, should the drill point catch and the drill body be knocked out of the workman's hand. A handy tool that has many applications is shown at Fig.

Fig. 60.-Showing Practical Application of Ratchet and Hand Feed

Drilling Machines.

60, A. This is mounted on a clamp bracket, has a screw feed, can drill holes at any angle and offers a wide range of adjustment in all directions. These are made in three sizes, one taking any drill up to 5-inch, a medium size that can be used up to 1 inch in diameter and a larger model that will bore holes as large as 114 inches in diameter. The medium size tool will be found sufficiently large to answer the requirements of any repair shop. The chucks provided will take either square shank or standard taper shank drills. It will be evident that this fitting can be easily clamped to any part of the frame and that large holes may be drilled with ease on account of the leverage provided. A somewhat similar fixture is shown at Fig. 60, B, this being in use with the ratchet drill shown at Fig. 59, D. The fixture, which is known as the "old man" in repair shop parlance consists of a vertical post attached to a slotted base that can be clamped in any desired position by bolts or straps. The ratchet drill has a hand-operated screw feed and the arm against which the pressure of the drill is exerted may be raised, lowered or swung around to any desired position. A fitting of this nature may be used in connection with a wide variety of ratchet heads. The advantage of the ratchet arrangement is that it permits one to drill holes in places where it would not be possible to turn a hand drill as the lever can be oscillated through a small are of a circle instead of a complete revolution. The special form of drill press shown at Fig. 60, C, can be changed over by a single trip from a drilling machine that will give a continual rotary motion to the chucks to a form that will give only an oscillating motion which is desirable in valve grinding. Another form of electrically operated sensitive drill press for the repairshop work-bench is shown at Fig 60, D. This differs in construction from that previously described in Chapter I, only in the method of drive which is by belt instead of friction dises.

Minor drilling operations with an ordinary hand drill are sometimes made difficult by the inability of the operator to hold the drill perfectly straight. The usual custom is to allow the head of the drilling tool to rest against the chest so that one hand may be used to get the brace straight and the other to turn the handle. This method requires much exertion, especially when a fixed piece

of metal is to be drilled and there is always a possibility of the hole being too large or drills breaking, due to swaying of the drill press. A very simple piece of apparatus described by Motor Age is shown at Fig. 61. This easily made jig enables the operator to keep the drill perfectly straight because one hand can be used to steady the drill. The jig is made of wood and of any convenient size to accommodate the particular drill press used. It

Fig. 61.-How to Use Hand Drills in Simple Homemade Drill Press.

consists of a block of wood forming a base with two uprights rigidly fastened to it by screws or bolts. These are drilled at their upper ends to take a piece of three-eighths inch steel rod which forms the fulcrum for the feed lever which is held under the arm, as the illustration clearly shows. A hole is drilled in the arm lever to take the head of the drill brace, as the detail shows, or if a breast drill is used instead of the hand drill, two pieces may be attached to keep the breast drill pad from turning, one at each side of that member. A drill press of this nature can be easily made from the odds and ends found in any repair shop and