Drill′ing-ma-chine′.
A machine carrying a rotating tool and a means for chucking the object to be bored. These machines differ greatly in size and appearance, in the mode of presenting the tool, presenting and chucking the work.The larger machines are frequently known as boring-machines (which see).
Fig. 1770 has a vertical drill-stock e and vertical adjustment d b c to the bed-plate. The driving portions h i j k l and feeding devices m n are evident.
Fig. 1771 is a radial drilling-machine in which the tool, in addition to the horizontal and vertical adjustment of the overhung-beam b, has a circular adjustment of the drill-stock o p in a vertical plane, so as to present the tool obliquely to the work. The whole machine swings around a stationary post in the center of the hollow column a, and the overhung-beam is vertically adjustable on the latter by means of a screw c, actuated by power, brought into action by the lever d seen at the top of the column. As it is desirable that no belts should intervene to mar the complete revolving sweep of the machine, the driving is applied through the center direct by shaft e, pulley f, and gears g h, and transmitted to the upright shaft, whence the horizontal shaft carries it to the spindle by means of two pairs of miter-gears, one of which is shown at j. This arrangement also [752] provides for the complete swiveling capacity of the drill-spindle, so that it can be used horizontally, vertically, or at any angle with equal facility. The movement of the head, inward and outward on the arm, is accomplished by the horizontal screw. r l m n o are the parts for feeding forward or retracting the drill p. The table q is for the convenience of the smaller class of work.
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| Radial drilling-machine. |
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| Sellers's horizontal drilling-machine. |
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| Drill-jar. |
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| Drill-press. |
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| Drill-stock |
Fig. 1772 shows Sellers's horizontal drilling and boring machine for car-boxes, with self-acting variable speed to drilling-spindle. See also boring-machine.
