Development of the Turret Lathe

Modified on 2016/11/28 23:51 by Jeff Joslin — Categorized as: History, Lathes, Metalworking Machinery

Origin of the Turret, or Revolving Head¶

BY E. G. PARKHURST.

_{Appeared in the May 24, 1900 issue of American Machinist.}

It may, or may not, be a matter of any public consequence who the inventor of the revolving turret head for screw machines was. If, however, it be considered of sufficient importance to be mentioned even casually, as in an article in the 'Engineering Magazine', November, 1899, it may as well be stated correctly as incorrectly.

Mr. H. D. Stone was not the inventor of the turret, neither did he (if the patent records be correct) take out patents on a turret machine in 1857, 1858, 1859 or 1860. The only one recorded for him is dated August 13, 1874, which in no way concerns a turret, except in adapting a feed through belt and worm gearing action, to the slide of a screw machine on which a turret is mounted.

Previous to 1853, Mr. J. D. Alvord, then a contractor at Sharp's rifle factory in Hartford. Conn, (who afterwards installed the Wheeler & Wilson Sewing Machine Company's plant at Bridgeport, Conn.) made plans for a turret head screw machine. A little later these were improved upon by Mr. Fred W. Howe, who at that time was superintendent for the Robbins & Lawrence Company, at Windsor, Vt. No one man in America during his lifetime did more to perfect metal-cutting machinery than did Mr. Howe.

The Howe screw machine must have been designed somewhere between 1856 and 1858. In 1860 I was shown one by Mr. Howe himself, and am positive that I saw stamped on it "Designed by F. W. Howe, and manufactured by Robbins & Lawrence, Windsor, Vt.," which firm put them on the market later. In 1859 revolving heads were in use at the Colt Patent Fire Arms Company's, at Hartford, supposed to have been designed by Mr. Lorrin Ballou, then one of the superintendents at the Colt works.

There were also plans and patterns made for turret head machines at the Stroud Works, Middletown, Conn., in 1857, the machine being in operation in 1858. In 1861 there were made at the above mentioned works some twenty-five machines, though I will add that the Howe pattern was pretty thoroughly copied.

About 1861 the justly celebrated Brown & Sharpe Company, of Providence, R. I., took up the manufacture of the Howe pattern. Mr. Joseph Brown soon added to it the self-revolving turret, through ratchet and pawl action by the return motion of slide, and later a feeding device whereby a rod of metal could be fed forward and secured without stopping the machine. Mr. Brown was the first to adapt the above named appliances to the Howe machine, though by no means the first in the field with self-revolving of the turret, or feeding and securing rods without stopping the spindle of a machine, as both these had been accomplished several years prior to 1860.

In 1861 Mr. F. A. Pratt and Mr. Amos Whitney (afterwards the Pratt & Whitney Company), of Hartford, Conn., took up the manufacture of the turret head screw machines, not the Howe pattern, but one of their own, which embodied the feature of a self-revolving turret. In this particular matter they antedate Mr. Brown's device. Many machines were made and put on the market from 1861 to 1870, when the old patterns were retired, and departures made which have since rendered them of world-wide reputation. At the Pratt & Whitney Company's works in 1869 two or three men were able to fill all orders on that class of machinery; today those employed number nearer two hundred. They have in all about 150 varieties, and the numbers manufactured have gone well up into the thousands.

During the period between 1852 and 1862 there were a number of eminent mechanics who almost revolutionized the mechanical world, by bringing nearer a state of perfection machinery for metal cutting, whose action could be depended upon for turning out work with precision. Many of these men have passed over the Broad River. Perhaps it would be of interest to some to know the names of those whose life labor was, and is, to perfect labor-saving machinery, and I believe it may be said that all of them, at some time, daily labored at the bench, from which, through their own exertions and native genius, they rose to fill the highest attainable positions in the mechanical world. The names of the gentlemen referred to as pioneers are E. K. Root, Sam. Batchellor, Lorrin Ballou, J. D. Alvord, R. S. Lawrence, F. W. Howe, F. A. Pratt, Amos Whitney, Charles E. Billings. All the above named brought out many new machines, which need not here be mentioned, during the period referred to, and all of them had a hand in either designing or manufacturing the revolving head screw machine.

Concerning the antiquity of the turret or revolving head for screw machines, I believe the facts in the premises warrant the assertion that one was made and used in 1845. and from that time until 1853 was in almost daily operation. In order that the reader may fully understand where the machine was made and what it was contrived for, I will give a history of the works where it originated.

In the year 1843 one Mr. Henry Ashton, of Middletown, Conn., a man of shrewd mechanical ability and an excellent workman, conceived the idea of placing a percussion lock (now obsolete) on the United States Service army horse pistol. At that period all service arms, both muskets and pistols, were flint-locked. Mr. Ashton, with his own hands, made a model percussion lock pistol, took it to Washington, and brought it to the attention of the then Secretary of War, who was so pleased with the model that he gave a contract for thirty thousand of them. Mr. Ashton came home with his contract and formed a copartnership with five other excellent workmen, like himself, whose names were Sylvester Bailey, P. H. Ashton, John North, Nelson Ashton and Ira N. Johnson. Each man put into the company one thosand dollars for a start capital, and on the strength of the contract the Middletown banks loaned then on their joint note money enough to prosecute their business until such time as they could turn in arms to the Government.

They selected a mill site having suitable water power at Middlefield, Conn, (now Rock Fall), then about four miles from any railway and off the carriage road, in the woods, under a hill; in fact, the buildings would not attract the attention of anyone traveling the main road, as from it nothing could be seen except a few chimney tops. It was in such an out of the way place that six excellent mechanics banded together, and their followers were selected from the workmen at the other three armories then in operation in other parts of the town. In the beginning they had to construct a dam and water wheel, erect buildings and construct machinery— for the most part from their own plans. In twenty-two months from date of contract five hundred pistols were delivered to the Government.

All parts of the arm were made by contract, and one Stephen Fitch, a genius, contracted to make the thirty thousand cones, and after signing papers to that effect he afterwards made, at his own expense, a self-revolving turret head screw machine, which from 1845 to 1853, as before stated, turned out excellent work.

Therefore, in consideration of all the facts in the case, it is but justice to the memory of Stephen Fitch to award to him the honor of being the originator of one of the greatest labor-saving machines ever invented.

At the time the Fitch machine made its appearance there was little or no demand for gun screws machined from the rod; none were used on Government contracts for arms, as those in control of ordnance matters flatly refused (said the threads would not hold) to take any except those forged from the rod. It was not until about 1862 that the army officials would consent to even consider the matter of using the turret head screw machines in Government armories.

OLD METHOD OF SCREW MAKING.

Gun screws were forged from the rod (Norway iron) under what was called a jumper, an upright frame secured in anvil block, in which were dies, one above the other, having an imprint in the face of each, counterpart of the screw to be forged, and cut off in individual lengths.

The hand apparatus for machining consisted of a wooden bench on which was mounted a flat bed in the form of a quadrant. Central from the outer circle was pivoted a jointed stand and mounted so as to slip easily through same was a shaft having at one end a hand crank, at the other a compensating clamp (in form of nippers) to secure and rotate the screw blank either by the head or body, as the two operations were required. Near the outer circle of bed were fixed, usually at equal distances, three upright frames, which controlled in such manner two dies each, one fast, the other to open up for milling bead; also one set for body and the third for threading the screw. All dies were closed on adjusting screws by weights, and opened up by foot pedals. Thus good, satisfactory work was accomplished, particularly in screw-thread size, as the cutting die controlled rather than the clamp on crank shaft, which had plenty of latitude in the before mentioned jointed stand.

AN EARLY AUTOMATIC SCREW MACHINE.

The first automatic screw machine we have knowledge of (not of the turret order) completed the screw, even to the nicking. It was devised by one Newell North, of Middletown, Conn., about 1848. It was several years undergoing experiments, and was finished in 1852 and successfully operated. There being no demand for its product, it was stored, about a year after which time it was destroyed by fire.

In 1874 N. C. Hubbell purchased from the Pratt & Whitney Company, of Hartford, a wire feed screw machine, and attached thereto an apparatus whereby the screws were threaded and nicked; in fact, it made what would be termed a finished screw from the rod. There were no distinctive alterations made on the machine, other than turning turret and slide for same up sidewise. Both turret and wire feed were operated by hand. Nothing of importance came of the arrangement (which operated fairly well), except it might be said that it was a connecting link between the hand and full automatic.

AUTOMATIC MACHINE.

The next one to take a hand was a man to whom your readers need no particular introduction—C. M. Spencer, second to none of American inventors. In 1880 he converted the Pratt & Whitney wire feed screw machine, pure and simple, into an automatic, by a central shaft, cams and levers, so that no hand operations were required other than to supply the rod from which the screw was made. Thousands of the machines are now in daily use for making screws and other articles too numerous to mention here. Mr. Spencer was the pioneer who opened up a field of vast magnitude, how vast one can determine by visiting any of the well-known establishments; for instance, the Hartford Screw Company. Since 1880 Mr. Spencer has brought out several automatic screw machines that in the way of production fairly eclipse his first effort, and his last—a very efficient one—strange to say, embodies the Fitch principle of the turret.

Since 1888 many skillful mechanics have brought out a variety of newly arranged machines. One has only to turn to patent records to find how many. The supposable reason for the lack of invention between 1880 and 1888 was the difficulty in obtaining a reliable rod feeding and holding device, such as that now in general use, which was held under patents the lapse of which, in 1888 (as was aptly stated not long ago by an eminent mechanical engineer), opened the doors wide and allowed inventors to come in. And it was the man from Middletown (see "Engineering Magazine," November, 1899) who so nearly closed the door from 1871 to 1888. He never directly received to the amount of one cent from his invention which is so universally used on both automatic and hand screw machines. What is referred to here are the inventions of Mr. Parkhurst himself, whose name is used to designate the wire feed for screw machines invented by him.—Ed.

TURRET HEAD OF THE FITCH MACHINE.

The only distinctive feature of the Fitch machine here shown is the revolving turret (carrying cutting tools) mounted in a head. The self-revolving mechanism, which was totally unlike any in present use, is not shown. It was a complicated affair because of the attachment of a hand lever to the wedge cam for releasing the index catch, and revolving the turret by a pawl and ratchet disk. I first saw the machine in 1852, again in 1870, the latter sight growing out of a controversy relating to the self-acting turret by the action of return movement of hand lever, which matter could not be satisfactorily settled without putting the machine in evidence. A special journey was made to Rockfall, Conn., the machine found in an attic; the silent witness told its own story about being self-acting. The gentleman who was my companion at that time is a very much alive and well known mechanical savant. The parties owning the machine would not sell, and it was destroyed by fire September 20, 1879.

The Billings turret here shown was designed in 1860. In general appearance it resembles the Colt machine, although embodying distinctive features added by Mr. Billings.

The Aston pistol shown is of the model of 1845, and the date on the lock plate is 1851. It is one from the last contract of 10,000. The cone in this pistol was made in the Fitch machine, and the pistol was presented to the writer by Captain Ralph Aston, U. S. N.

For the historical portion of this paper I am indebted to John North, the only surviving member of the Aston Company. Thanks are due also to C. E. Billings for assistance rendered and courtesies shown in connection with it.

The Fitch lathe, 1845. From 'Report on the Manufactures of Interchangeable Mechanism', 1883