BORIMI-MACIIINES, METAL These are classified under: I. Horizontal Boring Machines t II. Vertical Itoring-Machines.
I. IbutizoNTAL ACII The Niles Hori2ontal Boring, Drilling, and Xining machine is shown in Fig. 1. The machine consists of a heavy column it) ft. (I in. high, mounted on a bed-plate of any length to snit requirements. The column is 31 in. wide on the face, and is fitted with :se heavy saddle, 40 in. square, carrying the spindle. The saddle has a vertical traverse on the column of ti ft., and is raised and lowered by a heavy screw. It is ladaneed by a counter-weight hung in the eolninn. The boring and milling spindle is of hanimerol steel Si in. in diameter. it slides in a heavy revolting sleeve, and has a traverse of 4 ft.. It revolves in either direction, right or left hand. reversing by lever conveniently and ImA 8 power feeds, ranging from to in. per revolution of spindle. It is also provided with hand-feed and quick return. The are six in number, ranging from to in. per revolution of spindle. These feeds are applied only to the column and saddle, and are by power Any of these feeds for the quiek motion may he utilized to set drill, or milling-eutter to work anywhere on the surface which the machine will rm.!). At tine end of the bed-plate is placed the driving-gear, milling-feed. and quick-travers ing mechanism the column. The quick power traverse of the column has a speed of 5 ft. per minute. The tidying-pone has six steps for as 4-in. belt, and is strongly back-geared. givmg twelve chauges of speed, ranging from 2 to 200 revolutions per minute, and has ample power for boring up to 24 in. diameter. A platen is placed in front of the column, con venient to the spindle, for the operator to stand on.
A horizontal boring and drilling machine made by the Newark Machine-Tool Works is shown in Fig. 2. The work is bolted to the compound carriages which are shown directly under the boring-bar. the work being set square by the, top surface and the edges of the carriage. The carriages can be moved either across or along the movable table, which is shown sup ported by the two large screws. The table can
be lowered or raised from the side or at the end, as desired. A yoke of great strength braces the table, and serves as a bearing for the bar, or boring arbor. The boring-bar is fed by a rack and pin ion ; and it is held by a friction-clamp, so that, by easing the clamp and taking another grip, a very long feed can be obtained. There is a quick and slow hand. motion for the bar. The power-lift for the table is a feature peculiar to these machines. The lower ends of the table lifting-screws are carried by worm-gears threaded to serve as nuts. These gears take their motion from the worm-shaft. which is driven from the feed-shaft by means of the chain-gearing. In this way, the power from the driving-tone is used to lift the table, and this arrangement enables the workman to move the table without leaving his posi tion, and, when the work is nearly set, he can throw the power-lift out of gear and make the delicate final adjustment by band, using the slow-feed hand-wheel. The machine has self acting feeds in both directions, without reversing the directions of the motion of the cone, and a range of feed from + to g The Nicholson Boring-Machine is shown in Fig. 3. It uses for a tool a cutter on a fixed bar, and passes the work by the cutting point ; or, for large and heavy work, a traveling-head on a rotating bar with the work held stationary. To secure economy of time in setting, and to reduce the requirements for skill in the workman, the machine is provided with a broad flat table upon which to bolt the work. This table has a cross-feed, which secures the setting in the horizontal direction, and an up-and-down adjustment of the spindle locates the vertical. The heads are powerfully geared. the 40 and 50 in. sizes have eight and the 72 and 76 in. machines ten ranges of speed. Power applied to the cross-feed of the table admits of this machine being used for milling.