USRE371E - whipple - Google Patents

Description

3 Sheets-Sheet 1.

0. WHIPPLE. CUTTING THREADS 0P WOOD SCREWS.

No. 371; Reissued June 13, 1856.

3 Sheens-Sheet 3.

G. WHIPPLE. CUTTING THREADS OP WOOD SCREWS.

N0. 371.. Reissued June 13, 1856 UNITED STATES PATENT OFFICE.

OULLEN WHIPPLE, OF PROVIDENCE, RHODE ISLAND.

MACHINE FOR CUTTING THE THREADS OF WOOD-SCREWS.

Specification forming part of 'Letters Patent No. 2,75 dated August 18, I 42; Reissue No. 165, dated March 5, 1850; BeissueNo. 371, dated June 13, 18-36.

T 0 all whom it may concern:

Be it known that I, OULLEN WVHIPPLE, of Providence, in the county of Providence and State of Rhode Island, have invented a new and useful Machine for Cutting the Threads of food-Screws; and I do hereby declarethat the following is a full, clear, and exact description of my invention and of the manner of making, constructing, and using the same, ref- I erence being had to the accompanying drawings. making part of this specification, and in which- Figure 1 is a front elevation of the machine; Fig. 2, a'side elevation; Fig. 3, a horizontal section at the line :0 w of Fig. 1, and Fig. 4 a top view of the bed-piece which carries the blank tube and the arm which carries cutter.

The same letters indicate like parts in all the figures.

In this machine the blank to be threaded is held in and carried by a spindle or mandrel which has a rotating movement during the chasing of the thread, and a reciprocating longitudinal movement in the line of its axis, to determine the pitch of the thread and to return it for each-successive cut; and the chaser or cutting-tool is on an arm of a shaft which has a rocking motion to withdraw the chaser from the screw-blank at theendof each chasing operation, and to carry the chaser toward the axis of the screw-blank at the commencement of each operation, to determine the depth of each successive cut, and during each cut, to determine the form of the core or body of the screw. The motions necessary to be given to determine the pitch of the thread and the form of the core or body of the screw are governedby two cams, one of which performs the double function of determining the depth of each successive cut and the approach of the chaser or cutter toward the axis of the screw-blank during each cut to determine the form of the core or body of the screw within the thread; and, in addition to the motions above named, there is another cam or eccentric which operates a ratchet-motion to turn an indexwheel which determines the opening of a clutch or stcp motion to disengage the moving parts fromthedriving-pulleyordriving-shaftso soon as a screw is entirely threaded, that it may be removed and another blank inserted, and also at the end of each successive cut to shift the cam which determines the depth of each successive cut. The cutter or chaser ismade with a groove in one face to determine the form to be given to the thread, so that the said cutter or chaser may be sharpened by grinding from the'end alone and without changing the form of the recess or groove which determines the form of the thread.

The nature or principle of this invention which distinguishes. it from all other things before known consists, first, in giving the longitudinal reciprocating motion for determining the pitch of the thread in chasing the same, and for returning to repeat the operation by means of a wedge formed cam; second, in causing the chaser or cutter at each successive cut to approach nearer to the axis of the screw-blank by means of a cam which at each successive out acts by a greater radius; third, in regulating the depth of cut of the chaser or cutter along the length of the screw to give to it the required taper along the whole or any part of its length by combining with the chaser a cam of gradually-enlarged diameter; fourth, in combining the wedge-formed cam which gives the reciprocating motion to determine the pitch of the thread and to return for the repetition of the operation with the shaft or mandrel which carries and rotates the screw-blank by means of a tube in which the said shaft -or mandrel rotates, the said tube being acted upon by the wedge-formed earn to give the required longitudinal motion; fifth, in' combining the cam which deter mines the form to be given to the core or body of the screw with the cutter or chaser by means of a rock-shaft and lever, the said rock-shaft being provided with an arm connected with the said lever by means of a set-screw or other analogous means of adjustment sixth, in

shifting the cam which determines each successive cut of the chaser o'r'cntter by combining therewith a ratchet operated by an eccentrieor cam, the wheel of the ratchet being provided with pins that operate a lever that is connected with and which acts on the cam to shift it at the end of each successive cut; seventh, in operating a clutch or stop motion to disconnect the shaft or mandrel from the driving-power at the end of each complete operation of the machine by combining the clutch or stop with the ratchet by means of an index-wheel, which at the required periods liberates or acts upon the connections of the clutch or stop-motions; eighth,in making the chaser or cutter for chasing or cutting woodscrews by machinery with a groove in its outting-face of the form of the intended thread, or nearly so, that it may cut on both sides of the thread at the same time and finally on the edge, and admit of being sharpened by grinding on the end and without changing the form of the said groove; ninth, in combining with the mandrel a screw-driver for holding and rotating the screw-blank, while the thread is beingcut or chased thereon, a tubular rest for supporting the blank laterally and preventing it from vibrating or springing and climbing on the chaser or cutter; there being a slot or opening in the side of the tubular rest suffi cient to admit the chaser or cutter to operate on the blank, but leaving the latter surrounded:.as far as possible by the rest,that it may be firmly held on all sides.

In the accompanying drawings, A A A is the frame,which is usually made of cast-iron, and to which is ordinarily attached an auxiliary frame and stand, A A, of wood.

B is a driving-pulley, which may be turned by a band from a drum actuated by any motive power, and which is to be made to revolve with great rapidity-say at the rate of five hundred times in a minute.

. G G is the main shaft, spindle, or mandrel, upon which the pulley B is situated. This pulley revolves freely upon the shaft 0, except.

when clutched bythe sliding clutch M, which, when raised, engages with the pulley by means of the horns or catches mm on the clutch and pulley. The shaft then revolves with the pull ley B. the shaft and clutch being connectedby afeather. The clutch M is raised by the shipper N N, the end N of said shipper embracing the neck of the clutch between its collars M M. The shipper N Nis attached by a set-screw, z, in the socket Nto an upright sliding rod, G G, which passes through the sockets b b". The head G prevents the rod from descending too low, and it is raised by means of the handle Y, which constitutes a bent lever, as shown at Y Y, Fig. 2, the part Y being formed into a ring embracing the rod G, and bearing against the spiral' spring No. .2 surrounding said rod, said spiral spring causing the rod to rise with an elastic or yielding motion. forward, so as to cause the shaft 0 to revolve during the time a screw is being cut. When let go, it will fall back by its own weight and by that of the rod G, and the pulley B will be out of gear and revolve loosely upon its shaft. The shaftG C revolves and slides up anal down freely in the collars or sockets a and a, which are stationary and attached permanently to the frame. At its lower end the shaft 0 carries theholderD,which receives and holds the down.

The handle Y is to be drawn.

blank that is to be cut. This holder is in the form of a hollow socket or tube pinned or otherwise fastened to the shaft, and may be changed at pleasure to suit blanks of different sizes. It has within it a driver or sliding bolt, t, furnish ed with a projecting edge at its lower end,

which fits into the nick or slit in the head of the blank in the manner of a screw-driver, and holds it while itis being cut into a screw. The sliding bolt i is borne up by a spiral spring, (shown in dotted lines at No. 1,) which spring surrounds it, and it. is forced down by a cam or eccentric, j, that is turned by thumb-piece It. When a screw has been cut, as shown at 1, Fig. 1. the shaft 0 rests in the position represented in the drawings, admitting of the 1 ready removal of the screw and the feeding with a' blank, which is effected by the hand of the attendant. The shaft 0 O is made to slide up and down in the following manner while the screw is be-.

ing cut by a cam, H, or circular wedge,which is fixed onto the shaft or arbor E by means of its hub H", which may be screwed in place by a screw or wedge,and may be changed at pleasure for screws of different sizes. This cam orcircular wedge,with its shaft E, is made to revolve by suitable gearing from the shaft 0 O in the following manner:

a a is'a pinion on the shaft, spindle, or mandrel O, which pinion is made suiiicientlylong to keep it in gear white the shaft slidesup and It is attached to the shaft by means of a feather, and rests upon a collar, n, which is made fastto the shaft by a set-screw, 0, thus admitting of the adjusting of the place of the pinion a a upon the shaft. This pinion gears into a wheel, b b, which has attached to it the pinion'cc, gearing into the wheel d d on the cam-shaft E.

It will be manifest to every machinist that the manner of arranging the respective wheels and pinions and of communicating motion from the shaft 0 to the shaft Emay be varied; but I have given that which I have used and consider the most simple and convenient.

K is a box or socket through which the shaft C passes. without touching it, the opening through it being sufficiently large for that purpose.

L is a tube, which is fitted onto the shaft U and slides up and down with it. Said tube is received and slides accurately within the box K, and has a piece, L, projecting from its lower end,which,rests upon the circular wedge H, there being a slot through the side of the box K, through which the piece L passes, admitting the tube L to slide up and down, and at the same. time checking it from revolving with the shaft. The upper edge of the circular wedge Hit opened out would form a regular inclined. plane from the point h to the point h", the rise of which isto be equal to the length to. which a screwmhread is to be cut, the cutting continuing during the time the shaft 0 is.

rising. When the pi'eceL' arrives at the point sccnds, the piece L passing down the inclination from that point to h, when the cutting again proceeds.

Z Z (seen most distinctly in Fig. 2) is a stand or support under the pulley B, and making part of the frame of the machine.

p is a hollow stud to hold the d ri vingpulley, and q a nut on its end. P

1' r are a weight and stem, the latter of which-hears upon the upper end of the shaft 0, insuring its descent when permitted by the circular wedge or earn. The cutter or chaser,

by means of which the threads are to be cut,

is peculiar in its-form and act-ion, as it is made to out upon each side of the thread at the same time, and finally upon the edge, by which means said edge is made perfectlysmooth and even in a manner not heretofore attempted in the cutting of wood-screws. This cutter or chaser is shown in place at e c, Fig. 1, and a side view and cross-section of it are shown at 0". Its peculiarity consists in forming a groove on its convex or cutting side of such size and depth as shall adapt it to the thread to be out.

In making-these cutters I usually proceed in the following manner: I take a square piece of steel of suitable size, which I form into ahoop or ring. This I put into the lathe and face it truly on each side and turn it true on its outside or periphery, and then cut agroove in it around said periphery, as represented by the notch seen in the cutting end at 0, giving to said groove the desired shape and size of the intended thread of the screw. This ring I divide into sections and harden and temper these sections throughout their whole length. lhe groove and cutting face I render smooth and polished, and grindthe end or ends to such a bevel as' to give good cutting-edges on the grooved side. The width of the cutter on each side of the groove must be somewhat less than that of the space between each thread of the screw. As these cutters become dull they are readily sharpened, and this sharpening can be repeated until they are worn .too short for use. U is a steel bed piece or rest, which is bolted or fastened onto the bottom of the frame A. Through this a hole is drilled to receive a steel tube, 7:, the bore of which cor responds to the size of the-wire or shank of ihe blank from which a screw is to be cut. The bed-piece U alone may be used by drilling through it a hole of suitable size. The bed piece or rest must be so adjusted as to bring the hole through it directly under the center of the shaft 0, and it and the contained tube are to be slotted or cutaway on one side, as shown at h, for example, so as to admitthe cutter to operate on the blank. This tubular rest is of great importance, as it supports the blank firmly and steadily while under the op eration of the cutter or chaser, and prevents those irregularities in the thread of the screw which would result from any unsteadiness of the blank during the operation of threading it.

Fig. 4 is a top view of the bed-piece U, the

arm T, and the-cutter. The cutter is to be fixed in a cutter post or arm, T, at the lower end of the rock-shaft F, f being-a set-screw,

by which it maybe held in place, and ya key to prevent its turning on the shaft.

0 is a cap-piece which, by means of thescrew-bolt -d, holds the cutter in its place. The shaft or arbor F turns on gudgeous at its upper and lower ends in the parts a and a of the frame.

V is an arm made fast to theshaft F near to its upper end, and to the outer end of this arm is attached a spiral spring, No. 4, which draws it back and relieves the cutter e from its action, excepting when the arm V is forced forward by means to be presently described.

' X is a set-screw, which passes through the outer end of the arm V and bears upon one end of the curved lever \V, the fulcrum of which is the shaft F. The set-screw X serves to regulate the position of this lever. The arrangement of this part will be shown more plainly by the sectional view,Fig. 3,-which is made horizontal in the line or a of Fig. 1. In this figure \V is a top view of the aboveqiamed curved lever, having its fulcrum on the shaft F, and. bearing against the set-screw X at one of its ends, and against what I denoininate the conical feed -cam I at its other end. The conical feed-cam is situated on the shaft E, and slides up and down upon it by means of a feather, by which the two are made to revolve together. The cam I is in the general form of a frust-um of a cone; but it has a recess or cavity, 1, cut in it to receive theend of the lever- \V once in each revolution. This recess, corresponds with the descending parts it h of the circular wedge H, the lever V V fallinginto said recess by the action of the spiral spring No. 4 just before the-shaft C 0 begins to descend, and by this means the cutter or chaser c is withdrawn from the screw until the shaft 0 has reached its lowest point,-and as it begins to ascend the cam I will have'turned far enough for the shoulder of the recess 1 to act on the lever \V, and therebyto force the chaser or cutter against the piece to be out.

In order to feed the cutter to the blank, the

cam I is to be raised up'onthe shaftE at every successive action of the cutter, and as it acts by an increased diameter on the lever W it causes anew chip to be cut at each rise. The whole difference in the diameter of the upper and lower part of the cone is equal to the depth of the thread, and when the cone has been raised to its greatest height the cutting will be completed.

Although I have denominated this cam the conical cam, it is not absolutely conical, but its periphery or surface recedes from its axis or center in the manner of a scroll, and causes the chip taken off by the cutter to increase slightly in thickness as it proceeds, thus giving the desired taper to thescrew, the amount of which taper wii'l depend on the amount of enlargement of the conical cam from its scroll-like form. The recess 1, opposite to'tlie shoulder in which the lever W enters to permit the cutter ,to be drawn from the screw-blank, is curved so as to carry the cut ter or chaser toward the axis of the blank with a movement so fast as to make the conical form much more abrupt at the point than along the other parts of the thread.

The conical cam is successively raised, and other motions connected therewith are performed in the following manner:

0, Figs. 1 and 2, is awheel revolving on an arbor or stud, s, and having ratchet-teeth out upon its periphery.

O is a flange or rim projecting from the face of this wheel to the distance of half or three-fourths of an inch.

N is an inflexible arm in one piece with and extending back nearly at right angles from the shipper N. The end N of the arm N bears upon the rim 0 as the wheel 0 revolves until one of the notches a a, made through the rim, is brought under N, which then falls into it, allowing the shipperto descend, and throwa ing the pulley B out of gear with the shaft 0.

P P is a bent lever having its fulcrum at t, and being borne up at the end of its short arm P by the spring No. 3.

, Q is a catch jointed to ,thelever P, and opcrating on the teeth of the ratchet-wheel, so as to draw said wheel back to the distance of one tooth at every vibration of the lever P. This lever is acted upon by a cam, J, on the shaft E, and the distance of its play is regulated by a set-screw, w. i

S S are pins projecting from the face of the ratchet-wheel, and rising therefrom to thedistance of an inch and a half, more or less. The distance of these pins from the center of the wheel may be regulated by means of screwnuts and the slots 22 c. As the wheel 0 revolves, the pins S S are brought necessarily into contact with the arm R of the lever B R, and depress it until its end escapes from the pin. The short arm R (if this lever has a recess or hollow, 1, in the end of it, which embraces the bead r Won the lower end of the conical cam, and as the wheel 0 is drawn round to the distance of a tooth the cam is raised to a corresponding height. The number of shavings cut from each blank will correspond with the number of teeth between each section or pin S on the ratchet-wheel,the conical cam being raised to the full height in that distance of the movement of the wheel, and the lever B escaping from one pin to be acted upon by the next in the same distance.

To arrest the motion of the shaft 0,, so as to cause it to stand in the proper position for removing the cut screw, and for supplying a blank,a notch is formed in the bottom rim, M. of the shipper, Fig. 2, and a stump, m, is made fast to the frame, which stump is'received into said notch, this being so situated as to hold the shaft in the required position.

In using this machine the blank, while being acted upon by the cutter, is kept within a riphery.

tin or other box containing water or other fluid. This situation of this box is shown by the lines so a".

The above invention in many of its separate parts and combinations may be greatly varied within the principleshereinafter to be claimed or intended to be claimed-es, for instance,.

'the wedge form of the cam for determining the pitch of the thread, instead of being on the face of the wheel, might be made on the pe I am aware, however, that a reciprocating or vibrating cam or inclined slide has been used for analogous purposes in lathes, but not in the manufacture of wood-screws. The cam which determines the depth of each successive cut and the form of the core or body of the screw, instead of being a single cam, might be divided, and one used for each of the separate functions; or one of its properties might be dispensed with, for in making screws with a cylindrical core or body one of the properties of this cam is of no use, and the functions which tnc cams perform may be effected by combinations or arrangements of machinery different from those above described, although not to so great advantage; and the cutter or chaser, instead of being made in the form of airing, with the groove cut or turned in the outer periphery thereof, and then out into sections, may be made straight, with the groove cut in one face. It will be obvious, therefore, from the foregoing that many modifications may be made in the mode of constructing and applying the principles which distinguish this from other inventions before known for like or analogous purposes.

WVhat is claimed as new, and desired to be secured by Letters Patent, is-

1.' In combination with the shaft or mandrel which gives the rotary motion to the SCI'GW? blank, the employment of the rotating wedgeformed cam, or the equivalent thereof, for determining the pitch of the thread and for per-' mitting the return motion to repeat the oper- ,ation, substantially as described.

2. Causing the chaser or cutter at each successive cut to approach nearer to the axis of the screw-blank by means of a revolving conical cam, which at each successive operation acts by a greater radius, substantially as described.

3. Governing the motions of the chaser or cutte'r to make the core or body of the screw of a-conical or tapered form along the whole orany part of its length by combining therewith a cam of gradually-enlarged diameter, substantially as described,the form of such cam depending on the form intended to be given to the core or body of the screw.

4:. Combining the cam which determines the form of the core or bodyof the screw (to make it tapering or conical -in whole or in part) with the chaser or cutter by means of a rock-shaft and adj usting-lever, substantially as herein described, the said adjusting-lever being interposed between one of the arms of the rock-shaft and theface of the cam, so that by the use of, a set-screw or other analogous devicethe cutter or chaser may be readily set. as described.

5. Shifting the cam which determines each successive cut of the chaser or cutter by combining therewith a ratchet movement operated by an eccentric or cam,the wheel of the ratchet being provided with pins which operate a lever connected with the cam to shift, substantially as described.

6. Disconnecting the shaft or mandrel from the driving-power at the end of each complete operation of the machine by combining the clutch, or the equivalent thereof, with the ratchet by means of an index-wheel or perforated rim, which at the required periods liberates or acts upon the connections of the clutch to disengage it, substantially as described.

7. Making the chaser or cutter for chasing,

or cutting the threads of wood-screws by machinery with a groove of the form of the thread in its cutting-face and in the direction of its length, substantially as described, whereby the said chaser can be sharpened by Sim-- ply grinding ofi at the end and without changing the form of the groove, and whereby,a1so,

the said chaser cuts on both sides of the thread,

and finally on the edge thereof, as described. a

CULLEN YWHIPPLE.

In presence of- CHARLES F. TILLINGHAST, P. H. WATSON.

Images