Bar (hardware)

“ But to traverse the head carrying the tools along the bar necessitates a feed screw either within the bar or outside of it. If within, the metal removed to give it place weakens the bar, while in small holes there is no room for it; hence solid bars with fixed cutting tools are used for small holes, and tools held in a traversing head for those sufficiently large to give room for a head without weakening the bar too much. A boring bar is best driven from both ends. ”

“ With the files and saw you must cut away all the bars of your grating except one. This will leave room for you to climb through. The one bar must be left to secure a stout rope to, so that you may slide down it. The work of cutting the bars will take you all to-morrow; so after my visit to-night I shall not come again until the time arrives for you to make your escape. Be very careful to work silently, or you will be discovered, for spies are everywhere. When the bars are cut, put them back in their places, so that if anyone enters your cell they shall not notice the change. ”

“ After the live head has been bored the tailstock or back-head may be bored from the other end of the bar, so that the standards will not require to be moved on the bed until the boring is completed. The bar may be fed by hand, or an automatic feed motion may be affixed to one of the standards. ”

“ The common form of the smaller sizes of boring bar is that shown in Fig. 1127. a a being the bar, d d the lathe centres, b the cutter passing through a slot or keyway in the bar, and c a key tapered (as is also the back edge of the cutter) to wedge or fasten the cutter to the bar. It is obvious that, if the cutter is turned up in the bar, and is of the exact size of the hole to be bored, it will require to stand true in the bar, and will therefore be able to cut on both ends, in which case the work may be fed up to it twice as fast as though only one edge were performing duty. ”

“ The performer now places the bar to the extreme points of his fingers, and holds his arm in a horizontal position, when the bar is again seen suspended without any support in that most difficult position.
To prove that this wonderful performance is done without the aid of invisible silk, wire, wax, or mechanism, the operator places the bar against the back of his hand, and once more it is seen suspended in mid-air, while he takes it quite close to the company for inspection. Price, $2. ”

“ Rotate the bar by hand, and if the tool just touches the work without taking a cut the line of centres is parallel with the ways. If there is space between the tool point and the turned end of the bar, the tailstock requires setting over towards the back of the lathe, while if the tool takes a cut the tailstock requires to be set over towards the operator. If a bar is at hand that is known to be true, a pointed tool may be adjusted to just make a mark on the end of the bar when the slide rest is traversed. ”

“ In boring work chucked and revolved in the lathe, such, for instance, as axle boxes for locomotives, the bar shown in Fig. 1140 is an excellent tool. a represents a cutter head, which slides along, at a close working fit, upon the bar d d, and is provided with the cutters b, b, b, which are fastened into slots provided in the head a by the keys shown. The bar d d has a thread cut upon part of its length, the remainder being plain, to fit the sliding head. ”

“ It sometimes happens that, from play in the journals of the machine, or from other causes, a boring bar will jar or chatter at the commencement of a bore, and will gradually cease to do so as the cut proceeds and the cutter gets a broader bearing upon the work. ”

“ The public area was like an old-time pub. Anyone could wander in, plop down at the bar and start up a conversation with a group of locals. Just ring up the system with your modem and type in your details—real name, your chosen handle, phone number and other basic information. ”

“ The boring bar is one of the most important tools to be found in a machine shop, because the work it has to perform requires to be very accurately done; and since it is a somewhat expensive tool to make, and occupies a large amount of shop room, it is necessary to make one size of boring bar answer for as many sizes of hole as possible, which end can only be attained by making it thoroughly stiff and rigid. To this end a large amount of bearing and close fitting, using cast iron as the material, are necessary, because cast iron does not spring or deflect so easily as wrought iron ”

“ A stationary pin bolted upon the work catches one arm of the star at each revolution of the bar, and thus puts on the feed. To take up the wear of the tool-carrying slide, a gib m and set-screws p are provided, and to clamp the device to the boring-bar it is split at q and furnished with screws r. The boring-bar s, furthermore, has a collar at the top and a nut n at the bottom. The tool, it will be observed, can be closely held and guided, the degree of taper of the hole bored being governed by the angle of the slideway c to the axis of the sleeve. ”

“ The newspapers may be hung on light bars within the machine, these being supported at the end by a carefully-adjusted cross piece, which, on the insertion of a penny in the slot, moves just sufficiently to permit the end of one bar with its newspaper to drop, and to precipitate the latter on to a table forming the front of the machine. ”

“ Each matrix moves along until it arrives over the channel it is designed to enter when it comes to a gap in the teeth of the bar that are supporting it and drops into the magazine. Although there are but seven teeth on each side of the V-shaped bar, there are more than enough combinations possible to provide a characteristic one for every key of the keyboard. A matrix always has at least one pair of teeth in engagement with the bar until it reaches the gap that lets it fall into its own special channel of the magazine. ”

“ Machine.
This is a general description of the principles on which these machines are built, but, as in other classes, there are many variations in details. For example, there are the drop-bar, the web and the gripper methods of feeding these presses. In the first case a bar descends upon the paper after it is laid to point marks, and this bar, having a rotary motion, runs the sheet between a roller and a small drum into the machine. The web arrangement consists of a series of broad tapes which lie on the laying-on board and are fastened to a small drum underneath it. ”

“ This bar (Fig. 2) , for its simplicity, portability, and strength, has a reputation for being one of the most useful kinds of apparatus made. Not only is it used for a bar, but children’s swings, hand-rings, and trapeze can be attached to it, as the supports can be spread out to allow the bar to stand at various heights by shifting the stretcher irons (A A) up and down. These irons, three-eighths of a inch in diameter, are cranked at each end—i.e., bent at right-angles—and fit into holes in the uprights about 3 inches apart. ”

“ Thus, for instance, the impact caused by putting a key down should have the effect of driving a small weight upwards in the direction of a metal bar, the distance of which can be adjusted. Another bar, at a lower level, is also approached by a second weight, and the perfect degree of evenness in the touch is indicated by the fact [Pg 258] that the lower bar should be made to emit a faint sound with every note, but the higher one not at all. The closer the bars the more difficult is the exercise, and remarkable evenness of touch can be acquired by a progressive training with such an instrument. ”

“ Serial Operation—Digital computer operation in which all digits are handled serially.
Storage—Use of drums, tapes, cards, and so on to store data outside the computer proper.
The Computer’s Parts Looking at computers from a distance, we are vaguely aware that they are given problems in the form of coded instructions and that through some electronic metamorphosis this problem turns into an answer that is produced at the readout end of the machine. There is an engineering technique called the “black box” concept, in which we are concerned only with input to this box and its output. ”

“ They watched the "C" (reversed to them) appear and be completed. When the wobbly "H" grew to completion they laughed heartily. Then the hardwood bar had been dragged across the field of vision and up to the front windows, and they could only see the indiscriminate holes which appeared in the upper panels at frequent intervals. ”

“ Through a cable called a null modem, you can pipe valuable reports from your portable to a larger computer a few feet away. You may want to do this, anyhow. Your lap-sized computer simply may run out of storage room much more quickly than a bigger machine and may lack floppy disks to spread those bits and bytes around. So make sure your portable software lets you zip material back and forth between machines. ”

“ A bar screen is composed of parallel bars or rods. A mesh screen is composed of a fabric, usually wire. A grating consists of 2 sets of parallel bars in the same plane in sets intersecting at right angles. A band screen consists of an endless perforated band or belt which passes over upper and lower rollers. ”

“ On left is an array of 16 analog computers; at right is a large digital data-processing system.
The facility can perform scientific and business tasks simultaneously.
The dictionary also gives us a good clue to the digital computer: “Digital.—Of the fingers or digits.” A digital machine deals in digits, or discrete units, in its calculations. For instance, if we ask it to multiply 2 times 2, it answers that the product is exactly 4. A slide rule, which we have said is an analog device, might yield an answer of 3.98 or 4.02, depending on the quality of its workmanship and our eyesight. ”

“ An IBM 704 has proved a handy tool for blackjack players with a system for winning 99 per cent of the time, and rumor has it that a Los Angeles manufacturer plans to market a computer weighing only two pounds and costing $5, for horse-players. ”

“ To secure a more perfect operation of this wing, a bar, K, is extended across and directly underneath the front ends of the keys, so that whenever any key is depressed this bar is also depressed. Connected with this bar is a train of mechanism, which appears in the drawing and is described in the specification, but which is not necessary to be set out here in full. This mechanism operates directly upon the wing, I, and secures beyond peradventure the falling of the tablet, before the elbow of the next tablet rod has passed the upper edge of the wing. ”

“ A second hasp, similarly constructed, secures the lowest of the three bars; but, as that bar is behind, and not in front of, the shelf to which it belongs, the arrangements described above are reversed. One lock and key serves for the ironwork belonging to the three shelves.
Fig. 76. Iron bar and socket, closed to prevent removal of the bar: Hereford.
The chains are made of links of hammered iron as shewn in the sketch (fig. 78) which represents a piece of one of the actual size. There is usually a swivel in the centre, probably to prevent twisting. ”

“ The driving-cone, which is shown to be below the boring-bar, is so situated to accomplish two objects, which are to operate the two face plates by a shaft having two pinions (within the bed) gearing with the circumferential teeth on the face plates, and to operate at the same time the table (shown on the bed between the face-plates) to which the cylinder is bolted.
In a boring machine it is of the utmost consequence that the bar shall be as free from vibration as possible, while lost motion, or looseness from wear, is especially to be avoided. ”

“ Stick it in a Walkman and listen to all the little digits spin by? In hi-fi?"
"I've got a reader at home . . . but wait, there's a better way." She lifted it from my grasp and headed out onto the floor. "Ever hear of computer crime?"
"In passing."
"Good. Then what you're about to witness won't shock you."
I watched as she kicked on one of the NEC desk stations and loaded in a program. Next she walked over, flipped a switch on a little box, and a drawer glided out. In went Mori's shiny disk. Another button was pushed, the drawer receded, and the disk was spinning silently. ”

“ More than 1,000 variables are controlled, and 200 analog signals and 100 digital computer-generated signals are used in the process. The steel sheets are shot out of the rolls at some 45 miles an hour, or about 66 feet a second! A human supervisor would have a difficult job just watching the several hundred signals related to thickness, temperature, quality, and so on, much less trying to think what to do if he noticed something out of specifications. ”

“ Never satisfied, computer designers pondered the problem of all the lost time entailed in laboriously preparing cards or tapes for the ravenous electronic machine. The results of this brain-searching are interesting, and they are evident in computers that actually read man-talk. Computers used in the post office and elsewhere can optically read addresses as well as stamps; banks have computers that electrically read the coded magnetic ink numbers on our checks and process thousands of times as many as human workers once did. ”

“ This may be wrought out as in Fig. 5. The use of a bar of iron or steel is as shown. The bar is usually about 2 in. in diameter and several feet in length, so that it will rest firmly on a base of wood or stone. Then the bending is effected as at F, about the bar E, by repeated blows with the hammer. After a little practice, it is possible to describe almost any kind of a circle with the tools. The bar can be bought at an iron dealers for about 40 cents. From the junk pile of junk shop one may get a like bar for a few cents. ”