USRE684E - Improvement in machinery for making wood-screws - Google Patents

Description

2 Sheets-Sheet 1. C. WHIPPLE;

Machine for Shaving Heads of Wood Screws. H No. 684. Reiss'u ed April 12. 18,59.

N. PETERS, PhwtvLiihognpher, Washington D. C.

2 Sheets-Sheet 2.

c. WHIPPL'E. Machin for Shaving Heads of Wood Screws.

Beigsued April 12, 1859.

UNITED STATES PATENT OFFICE.

(JULLEN \VIIIPPLE, OF PROVIDENCE,

RHODE ISLAND, ASSIGNOR, TO NEW ENGLAND .SOREVV COMPANY.

Specification l'ori'ning part of Letters Patent No.9, 640, dated December 7, i852; antedated June '7, 1852; Reissue N0. 684, dated April 12, 1859.

To aZZ whont it may concern:

Be it known that OULLEN WI-IIPPLE, of the city and county of Providence, in the State of Rhode Island, did invent a new and use ful Improvement in Machinery for the Mannfacture of Wood-Screws, of which the following is a full, clear, and exact description, reference being bad to the annexed drawings, which make part of this specification, and in which Figure 1 represents a side elevation, Fig. 2 an end elevation, and Fig. 3 aplan, of a machine for shaving the heads of wood-screws, (complete with the exception of the hopper and its adjuncts,) showing one application of said'improvement. Fig. 4 represents, 011 an enlarged scale, the mandrel in section, together with an elevation of the mechanism connected therewith for holding and liberating and for discharging the blank; and Fig. 5 represents a transverse section through the rear of the mandrel at the line as a: of Fig. 1.

In machines designed to dress screw-blanks automatically while fixed in a revolving man- (I rel, it is important, in order to prevent irregularity in the size, form, and finish of the screws,

that the mandrel should be free from end motion, and therefore free from such end-thrust or wear on the end bearings as will give rise to end motion and one branch of the saidimprovement consists of a mechanism for chucking screw-blanks automatically and holding them while being'd-ressed, so constructed that the movements concerned in opening or closing the jaws ofthe chuck, orin holding them closed, shall not produce endwise pressure upon the mandrel while the blank is being operated on by the cutter.

The machine represented in the accompanyingdrawings consists, mainly, of a hollow mandrel; of a pair of gripping-jaws carried by the mandrel, which grasp the blank, hold it while being dressed by a cutter, and liberate it when dressed; of suitable mechanism to discharge the dressed blank; of a reciprocating tool-holder which carries the tool forward to dress the head of the blank and withdraws it when the head is dressed; of shafts with pulleys, cams, and other mechanism to give motion to the several acting members of the machine, and of a frame to support the several parts of this mechanism.

The in andrel. has its beari n gs in puppet-heads B B, and the portion of it between the puppetheads is enlarged and turned into the proper form to act as a pulley for the belt which gives it motion. The gripping-nippers D D are supported between apairoflugs, U G, that project from the front extremity of the mandrel, and are secured there by joint-pins a a, which pass through thelugs and the nippers. The shanks D D of the nippers are made long to give them considerable elasticity, extend to near the rear end of the mandrel, and are forced toward each other by springs b b, to keep the jaws open when not grasping a blank. The jaws are shut by forcing the shanks apart, which is effected in this instance by means of a pair of toggles, E E, divergingfroma central block, F, which has two arms, e e, that slide in grooves in the mandrel to guide the block. This block forms the head of a bar, F, whose axis is in line with that of the mandrel, and

whose hinder extremity is swiveled to a crosshead, F between a pair of standards, G G, on the hinder extremity of the bench A. The inner sides of these standards have grooves on a levelwith and parallel to the axis of the mandrel for the cross-head to slide in toward and from the endof the mandrel. The inner extremities of the toggles are seated in sockets in the head F, and their outer extremities in boxes 9 g in recesses in the hinder extremities the bar F and the block F. The other arm of the lever enters a slot in the upper extremity of a bar, I, that slides up and down in suitable guides. Thelower extremity of this bar carries an anti-friction wheel, h, within the range of two revolving cams, J J, on the shaftK, which alternately elevate and depress it, to raise and lower the bar I, and to vibrate the lever H.

When the blank has been introduced between the grippin g-jaws by the feeding mechanism, (which, as itforms no part of the particular improvement secured by this patent, need not here be described,) the cam J, through thebar I and elbow-lever H, forces the bar 1*" and block F forward, extending the toggles and thrustin g the nipper-shanks apart, thereby closing the jaws upon the blank. The movement of the bar 1 is continued until the toggles are pushed slightly beyond astraightline, to cause them to rest locked against the stops as w on the shanks D D and hold the grippingjaws firmly closed. The relaxation of the grasp of the jaws upon the blank, when the toggles are thus beyond a straight line, is prevented by the elasticity of the shanks. At this stage of the operation, and until the blank is dressed, the further exertion of force by or upon the crosshead F is suspended. Under this arrangement the whole system of forces concerned in maintaining the hold of the jaws upon the blank (which consists of the mutual actions and reactions of the stops or holdfasts w w, the toggles, the shanks and jaws of the'nippers, and the blank) resides and terminates wholly within the mandrel itself, and therefore can produce no thrust upon the mandrel tending to force it against its end bearings.

The blank being dressed,.the cam J comes into action, and, through the medium of the bar I and lever H, draws the bar F and block F backward, flexing the toggles, and allowing the jaws to open and release the blank.

The said improvement has been described as applied to machinery specially adapted to shaving the heads of screw-blanks; but it is evident that it may be applied to machinery for performing other operations in dressing screw-blanks.

Instead of thetogglelevers to open and close thejaws of the grip ping-nippers, various other known devices may be used in connection with a suitable holdfast, with like efl'eet. These and other modifications of the mechanism, if circumstances should render it expedient to make them, can readily be carried into practice by skillful mechanicians.

What is claimed under this patent as the invention of the said OULLEN WHIPPLE is 1. In combination with a mandrel which carries chuck or gripping-jaws, an automatic mechanism for closing said jaws upon the blank, keeping them closed to hold the blank while bein gdressed, and then opeuingthem to release the dressed blank, arranged and operating in such manner as to leave the mandrel (during the time that the blank is being acted on by the cutter) free from endwise pressure by the chucking mechanism.

2. The combination of toggle-levers carried by the mandrel, a stop or holdfast, also carried by the mandrel, to lock and hold the togglelevers when pushed beyond a straight line, and gripping-jaws with shanks having sufiicient elasticity to maintain a firm hold of the jaws upon the blank when the toggle-levers have passeda straight line, substantially as herein set forth.

In testimony whereof the said company has hereunto signed its name and affixed its seal.

NEW ENGLAND SCREW COMPANY, By HENRY L. KENDALL,

Agent. Witnesses:

P. H. WATSON, HENRY BALDWIN, Jr.

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