Chuck (machine)

“ Figs. 806 and 807 represent a class of work that it would be very difficult to chuck and operate on without the aid of a cone plate. The former requires to have a left-hand thread cut in its bore a, and the latter a similar thread in end a. A universal chuck cannot be used to drive the work, because in the former case it would damage its thin edge, and in the latter the jaws would force the work out of the chuck ”

“ The chuck is waxed or cemented by rotating it at high velocity while holding the sticks against it. The whole surface of the chuck being thus coated, the centre of the work is forced on the steel point c, and the lathe is kept running until the surface of the work nearly touches that of the chuck, when the belt is passed to the loose pulley overhead and the work forced against the chuck surface until it stops or else revolves the work against the hand pressure, the friction between the surfaces having melted the wax or cement, and cemented the work to the chuck. ”

“ It is better that the thread of the chuck be not too tight a fit upon that on the lathe spindle, the radial face of the chuck hub and of the cone spindle collar being relied upon to set the chuck true, because it is somewhat difficult to produce threads so true as to hold the faces true. ”

“ On account of the spring of the parts, which occurs when the strain is transmitted from one part to another, it is desirable when using the chuck as a universal one to first operate one screw to grip the work and then pass to the others and operate them so that they may receive the pressure direct from the screw head and not entirely through the medium of the rack, and there will be found enough movement of the screws when thus operated to effect the object of relieving the rack to some extent from strain. ”

“ Fig. 892 represents a view of the end l as held for the second chucking. c is a section of the chuck plate, and o o represents the line of centres of the lathe, and it is obvious that the radial face of the lever end (which is here represented by l) being used for all but the first chucking, the holes will all stand axially true one with the other, no matter how many chuckings and holes there may be, hence it becomes obvious that the face that will meet the chuck plate is the one that should be turned at the first chucking. ”

“ Sometimes the length of work that may advantageously be driven by such a chuck is so great as to render the use of the dead centre to support one end necessary, in which case the rod should be removed from the chuck before each piece is turned, so as to centre drill the dead centre end. ”

“ The advantages of the screw machine are, that the work requires no centring since it is held in a chuck, that forging operations are dispensed with, that any number of pieces may be made of uniform dimensions without any measuring operations save those necessary when adjusting the tool for the first piece, and that it does not require skilled labor to operate the machine after the tools are once set. ”

“ When the rack is in gear, the chuck is a universal one, all the jaws moving simultaneously and equally, whether they be set in such position in their slots as may be necessary to grip an oval or round piece of work; when the rack is out of gear the jaws may be moved by their respective screws so as to run true as for round work, or to hold the work to any degree of eccentricity required. ”

“ There is one special advantage in driving small work in a chuck of this kind, inasmuch as the work can be tried for fit without removing it from the lathe, while in some cases operations can be performed on it which would otherwise require its removal to the vice; suppose, for example, a thread of very small diameter and pitch requires to be cut on the work end, then a pair of dies or a screw plate may be placed on it, and the lathe pulled round by the belt ”

“ For the chuck the upper part of the cavity of a metal cylinder is bored out so as to fit on the driving spindle. Below this bore a square recess is made, and below this latter and coming well within the diameter of the square recess, is a circular hole passing through the end of the chuck. The drill holder or socket is in a separate piece, the bottom portion of which is provided with a square or round recess for holding the drill shanks, and is held firmly in its socket by means of a set-screw. ”

“ A common method of chucking such a crank is to level the surface of the crank in a planing machine, and to hold that surface to the chuck-plate by bolts and plates, while boring both the holes, merely reversing the crank end for end for the second chucking. ”

“ Fig. 704 shows in section the front bearing and the automatic chuck. m is a hollow spindle within which is the hollow spindle h, through which the rod or wire to make the work passes. It is prevented from end motion by the cone hub on one side and the collar j on the other side of the bearing, while h may be operated endwise within m by means of the hand-lever shown on the left-hand of the headstock in the general view. The core a of the chuck screws upon m, and is threaded to receive the adjustment nut b, which receives and holds the adjustment wedges c at their ends by the talon shown. ”

“ Figs. 692 and 693 represent a screw machine for general work.
a is a chuck with hardened steel V-shaped jaws. It is fast on the hollow arbor of the machine. b is a steadying chuck on the rear end of the arbor. The arbor has a two and one-sixteenth hole through it and its journals are very large and stiff. It is of steel, and runs in gun-metal boxes. The cone pulley and back gear is of the full proportion and power of an eighteen-inch lathe. c is an ordinary lathe carriage fitted to slide on the bed, and be operated by hand-wheel d and a rack pinion as usual. ”

“ The self-centring chuck is an accessory which has proved invaluable for saving time. It may most easily be described as a circular plate which screws on to the inner end of the mandrel (the spindle imparting motion [68] to the object being machined) and has in its face three slots radiating from the centre at angles of 120°. In each slot slides a stepped jaw, the under side of which is scored with concentric grooves engaging with a helical scroll turned by a key and worm gear acting on its circumference. ”

“ As the outer portion of the chuck is rigidly secured to the shell, C, by screws, of course when that shell is jammed, as already stated, by the nut, E, it becomes impossible to turn the chuck bodily; and hence the bevel wheels cannot be rotated around the main gear wheel, and consequently the position of the jaws cannot be altered. The above comprises the mechanism proper of the device, that is to say, all that is necessary for moving or clamping the jaws. ”

“ Special spacing devices for the back gage are revolutionizing many branches of work. The usual screw or cable is relatively slow and undependable and requires care and time to move the work the exact distance required.
The new way is to equip the cutting machine with a back gage operating mechanism having stops which can be set for any width to be cut. The operator simply pulls a lever between the stops, which instantly moves the pile and measures it exactly. Production has been increased six hundred per cent. ”

“ Under the keys runs a rod connected by a crank motion with the pusher G, which, with every depression of a key, pushes forward the line of type in the composing stick, thus making room for the next letter. The matter is thus set in one continuous line, ready to be divided into lines of the required length either by the operator at the machine or by another hand working in conjunction. The speed of the machine varies from 6000 to 12,000 types per hour, but is regulated solely by the skill of the operator, as the machine will work as fast as the keys can be pressed. ”

“ As wooden chucks are liable to warp and become out of true it is requisite to test them on each occasion before use, and true them if necessary. The work is fastened to these chucks by means of screws whose heads are sunk beneath the work surface a sufficient depth so that there is no danger of their coming into contact with the turning tools. ”

“ The logical-truth calculator built by Kalin and Burkhart is not giant in size, although giant in capacity. Like other mechanical brains, the machine is made up of many pieces of a rather small number of different kinds of parts. The machine contains about 45 dial switches, 23 snap switches (or two-position switches) , 85 relays, 6 push buttons, less than a mile of wire, etc. The lid of the metal box is the front, vertical panel of the machine. ”

“ Electric auxiliary mechanism has also been devised to start or stop the main machine slowly, and thus prevent injury to small or delicate parts of complicated machines, like printing presses for instance. Clutches are arranged sometimes in the form of weights, resembling the action of the weights in steam governors, whereby centrifugal action is relied upon for swinging the weights outward to effect a clutching and coupling of the shaft, or other mechanism, so that two lines of shafting are coupled, or the machine started, or speeded, at a certain time during the operation. ”

“ I hedged, eight days later, looking at the repaired, refurbished, and amended gadget on the table. "Remember, Artie, the more parts to an invention, the more things can go wrong with it. In geometric progression...."
"Unh-uh," he shook his head. "Not the more parts, Burt. The more moving parts. All we've done is added a parabolic sound-reflector, to force all the waves the cones make down through a tube in the middle of the machine. And we've insulated the tube to keep extraneous vibration from shattering it with super-induced metal fatigue." ”

“ The chuck plate, on which the work is fixed, is connected, by a train of gearing on its back, with a fixed gear about the spindle on the head stock, so that when the relation these gears bear to one another is altered, the motion of the work on the chuck is accelerated or retarded, or is made to assume certain positions. An elliptic chuck is quite another thing, the work done by it is shown in Fig. ”

“ Machines embodying the principle of the master lead screw are found in constant use by industry at the present time for specialized application. Whenever technological changes again reopen the topic of thread-cutting to a new degree of accuracy or call for a reevaluation of popular methods for any other reason, we may expect to see another resurgence of the master-screw method, for no other design eliminates so many variables or rests on such firm and fundamental natural principles as the machine of Das mittelalterliche Hausbuch of 1483, the earliest such machine now known. ”

“ It is to be observed, however, that the cutter could not be reversed if it was driven by an arbor that screwed upon the driving spindle of the milling machine. For if the machine has a right-hand thread then the cutter must revolve in the direction of g, and the work feed must be in that of c; whereas if the machine spindle drives its chucks, arbors, &c., by a left-hand thread, then the direction of cutter revolution must be as at f, and that of work feed as at d. ”

“ It is true that the professionals in machine-making have done much to smooth the path of the amateur. Some of the semi-automatic and automatic machines are so wonderful that one might imagine them endowed with life and professional skill themselves. I have watched, fascinated, the work of a screw-making machine which, after turning the tiny thread, reached over a steel finger and thumb, picked up the screw, lifted it back to a new position and jammed it there for another tool to slide forward at the precisely right second and cut out the cross-nick on the screw-head. ”

“ There are some twenty-two thousand electron tubes in each one, you know, and so we devised a gadget that went down the aisles and replaced them one after another automatically. Now, the machine must have started from that crude affair and by using its cable-clamps, worked on another machine capable of more complex action. Sort of like a lobster fashioning a hammer out of a rock with its claws. Then the more complex machine must have rebuilt the repair-gadgets, making them even more facile—and so on until we have the completely capable machine. ”

“ A guard is placed over the emery wheel to arrest and collect the water cuttings, &c., which would otherwise fly about.
A large amount of work which has usually been filed in a lathe, can be much more expeditiously and accurately finished by grinding in this machine.
Work to be ground may obviously be held in the same chucks or work-holding appliances as would be required to hold it to turn it with cutting tools, or where a quantity of similar work is to be done special chucks may be made. ”

“ A double-panel plugboard or a triple-panel plugboard applies to some machines. In less time than it takes to describe it, we can take one wired-up plugboard out of a machine and put in a new wired-up plugboard and thus change completely the instructions under which the machine operates. Many of the machines have a number of different switches that we must also change, when going from one kind of problem to another.
The numbers that are stored or sorted in punch-card machines may be of any size up to 80 digits, one in each column of the punch card. ”

“ Any of the augers or bits that are used in boring by hand may be used in a boring machine, but it is obvious that, as the bit or auger is forced to its feed by hand or foot, and as its revolution is very rapid, the screw point, which is intended as an aid in feeding when the bit is used by hand, is not necessary. ”