US9477A - Island - Google Patents

Description

2 Sheets-Sheet I.

C. WHIPPLE.

Making Screws.

Patented Dec. 14, 1852 2 Sheets-Sheet 2. C. WHIPPLE.

Making Screws.

No. 9,477. Patented Dec. 14, 1852.

UNITED STATES PATENT OFFICE.

CULLEN IVHIPPLE, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO THE NEW ENGLAND SCREW COMPANY.

MECHANISM FOR POINTING AND THREADING SCREW-BLANKS IN THE SAME MACHINE.

Specification forming part of Letters Patent No. 9,477, dated December 14, 1852.

To all whom it may concern.-

Be it known that I, CULLEN WHIPPLE, of the city and county of Providence, in the State of Rhode Island, have invented certain new and useful Improvements in Machinery for Pointing and Threading WVood-Screws, of which the following is a full, clear, and exact description, reference being had to the annexed drawings of the same, which make part of this specification, and in which Figure 1 represents a front elevation of a machine with my improvements applied thereto, but in its general construction and arrangements, except in so far as relates to the improvements, resembles the threadingmachine for which Letters Patent of the United States of America were granted to me on the 18th day of August, in the year 1842, and subsequently (on the 5th day of March, 1850) reissued according to law. Fig. 2 is also an elevation of the side of the machine on the left of the View represented in Fig. 1, with a portion ofthe frame removed; and Fig. 3 is a horizontal section looking clownward from the line a; 00 of Fig. 1.

Myinvention and improvements consist in the particular construction and arrangement of the mechanism for pointing the blank and threading it by means of diffgent cutters in the same machine held in and operated by the same tool-holder and having a common motion whereby the pointing and threading of the blank are performed at a single operation in a practically-successful manner, as I have demonstrated by the uninterrupted use of the machine herein represented and described during thepresent year.

Such parts of the machine as are not in the present specification particularly claimed will only be referred to briefly, the description in detail being restricted to the parts that constitute the subject-matter of the claim.

The drawings represent a strong frame A, which supports the other parts of the machine, among which 13 is the tubular rest for supporting the blank while under the action of the cutters.

O is the discharging-rod, which at the proper time enters the rest in the manner of a piston and discharges the finished screw, and is then immediately withdrawn to perthe driving-shaft.

mit a rough blank to be placed in the rest, to be in its turn pointed and threaded.

D is the screw-driver or turn-screw by means of which the blank is rotated while under the action of the cutters.

The mandrel D of the turn-screw is made It receives motion from the driving-pulley E and transmits this motion through a pinion F, mounted near its middle, and through the reducing gear-wheels F F F to the cam-shaft G, which by means of its cam M regulates and controls the 1ongitudinal movement of the cutters along the blank, so as to determine the pitch of the thread.

H is a turning and sliding bar, which carries the tool-holder I to traverse the cuttingtool lengthwise of the blank, and which will be described presently.

Beneath the wedge-formed cam M, for determining the pitch of the thread, a conical orconoidal cam N is mounted on the shaft G, for determining the depth of the successive cuts by which the thread is formed by acting aTTaach successive out with a greater radius. This cam regulates the position of the toolholder through a lever J, which at one end carries a shoe to bear upon the face of the cam and at the other end carries a gage-plate j, on which the arm K slides, and which turns the shaft H with its tool-holder I toward or from the rest, as it is moved forward or back, and thus causes the cutters to approach toward and-recede from the axis of the blank. The cam N has one portion of its periphery n, which is designed to control the chasing-tool when acting upon the point of the blank, eccentric to its axis of rotation and more protuberant than the rest, in order that the tool may by this sudden elongation of the radius of the cam which controls its position be caused to approach suddenly toward the axis of the blank and produce upon it a short blunt point, as represented.

The thread is formed by a succession of cuts of the chasing-tool made successively deeper by changing the position of the conical cam to cause it to act by radii of gradually-increasing length. The position of this cam is changed as follows: A wiper L on the cam-shaft, acting through the long arm L of a lever, actuates a pawl L on its shorter arm that takesinto aratchet-wheel O on a countershaft P. The latter carries a Wedge-shaped cam Q, which, acting upon a lever B, raises the conical cam N, so as to bring successive sections of its length of gradually-increasing radius to act upon the treadle J to turn the shaft H and move the cutter toward the axis of the blank. The acting face of the cam Q has different degrees of inclination to its axis, so that by the turning of the ratchet-wheel 0 one notch at each revolution of the camshaft G, which corresponds to one cut of the chaser, the latter will at the commencement of the operation of threading a blank take rank hold and remove the surplus material rapidly, while toward the end of the operation or during the last cuts of the chaser it will take shallow cuts and operate to trim and so give a smooth finish to the screw. A spring L is attached by a strap L passing over a pulley U, to the arm L of a lever on the sleeve L on the shaftP to hold it against the cam L and to return or draw back the pawl L after it has been advanced to turn the ratchet-wheel 0 one notch at the end of the I stroke of the cutter.

b is a disk also mounted on the countershaft P, that supports an arm S, connected with a shifting-rod T, that holds the mandrel D in connection with the driving-power during the operation of pointing and threading a blank by means of a clutch D and arm D but when the screw is threaded the arm S is permitted to drop into a notch in the disk S to shift the clutch, and thus disconnect the operatin g parts of the machine from the drivingpower.

T is ahand-lever to raise the shifting-rod T to lift the arm S to unlockthe machine and at the saine time to raise the arm D and clu tchD to throw the latter into gear with the driving-power and set the machine in motion.

U is is a lever-handle that by turning in one direction bears against an arm U of a rock-shaft and depresses the same and simul taneously depresses a second arm U that clutches by its forked extremity a collar U on the mandrel D of the turn-screw. By reversing the movements of the lever-handle Uthe turn-screw is raised to liberate the blank. The former of the movement just described takes place at the beginning and the latter at the end of the operation of threading and pointing a screw. A spring U is connected with the arm U of the rock-shaft in such manner as constantly to tend to keep the turnscrew raised from the rest. The sliding and turning bar H, that carries the tool-holder I, is held in contact with the face of the wedgeformed cam M, that traverses it by a spring H. The tool-holder I is a standard secured upon the sliding and turning bar Hj The head of this standard is perforated to receive the chas' .nlg hepnietingztnqlel fi tool is clamped in its seat by a screw 7) and the pointing-tool is clamped in its seat by a screw 0. The tools thus arranged in the head of the handle stand at right angles to both the sliding bar H and axis of the screw-blank n, and they also stand at a distance from each other equal or thereabout to, the length of the screw-thread to be cut on the blank. The pointing tool 0 projects fartherfrom the holder toward the blank than the chaser, in order that it may come into contact with the blank and perform its office before the chaser begins to act, and that this may be done conveniently the chaser is brought very slightly nearer to the head of the blank than usual, and is not pressed inward by the action of the conical cam so as to commence its out until the holder has moved far enough toward the point of the blank to remove the cutting-edge of the pointing-tool far enough from the surface of the blank to prevent it from cutting while the chaser is acting. The sliding bar on which the tool-holder receives two motionsone longitudinal and derived from the wedge-shaped cam M and the other motion an oscillating or rocking at right angles to the first and derived from the conical cam N. These motions thus derived are communicated to the tools, the longitudinal traverse giving the pitch to the thread and the transverse traverse or oscillation regulating the depth of the thread. The Wedge-formed and conical cams have each a dead motion between the completion of one cut and the commencement of another, and the dead motion of each is of uniform radius throughout its whole length, so that the cutters will fall back both transversely and 1011- gitudinally to the same point after each out. These cams are also so shaped that by a given angular motion they will impart a transverse movement to the tool-holder that will bring its cutters at the commencement of each stroke to the same distance from the blank at the instant the longitudinal movement commences, in order that the pointing-cutter may by a transverse movement of the holder be caused to perform its office before the chaser begins its first cut, and then, as the wedge-shaped cam M begins to act, giving a longitudinal movement to the holder, that the pointer may be carried out from the point of the blank, so that it can no longer cut the instant the movement of the cams exceed the said given angular distance, by which means the chaser is free to cut deeper and deeper at each successive out without bringing the pointing-cutter into action after the first cut. The edge of the pointing-tool should be beveled off until it is parallel to the side of the point required to bemade by it, as represented in Fig. 1, and the distance to which the cutting-edge of this tool should be advanced beyond the point of the chaser, as before stated, should be equal to the difference between the depth of the thread and the radius of the blank, so that the thread may run to a point. If a sharp point is not required,then the projection of thecutter beyond the chaser must be correspondingly diminished. By this arrangement a separate cutter in the same tool-post is made to relieve the chaser of the severe duty of reducing the end of the blank I to a point without increasing the number of cam movements or otherwise adding to the complexity of the machine beyond the mere affixing of a pointing-cutter to the tool-post which carries the chaser.

What I claim as my invention, and desire to secure by Letters Patent, is

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