US827659A - Screw-machine. - Google Patents

Description

N0. 827,659. PATENTED JULY 31, 1906.v W. B. PEARSON & C. E. ROBERTS.

v SCREW MACHINE. AFPLIUATION FILED sBPT.9,19o4.

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m1822659. PATENTED JULY 31, 1,906.v w. B. PEARSON 6 o. E. ROPtBRTs. SGRBW MACHINE.

APPLVIUATION FILED SEPT. 9, 1904.

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PATENTED JULY 31, 1906. W. B. PEARSON & C. E. ROBERTS.

SCREW MACHINE.

APPLICATION FILED snPT.9,19o4.

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IIIIIIUI! No. 827,659. PATENTBD JULY s1, 1906.

W. B. PBARSON & c. E. ROBERTS.

SCREW MACHINE.

APPLIUATION FILED sEPT.9,19o4.

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No. 827,659. PATENTED JULY 31, 1906.

W. E. PEAESON & c. E. ROBERTS, f

SCREW MACHINE.

APPLIOATION FILED SEPT. 9, m04.

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SCREW MACHINE. APPLICATION FILE D'SBPT.9,1904.

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UNITED STATES PATENT OFFTCE.

wALTER s. PEARsON, or AND CHARLES E. RORERTs,

OF OAK PARK, ILLINOIS, ASSIGNORS TO STANDARD SCREW COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF NEW JERSEY.

SCREW-MACHINE;

Original application led May 9,1902, Serial No. 106,620. Divided and this application filed September 9,1904. Serial N o. 223, 881.

ASpecification of Letters Patent.

Patented July 31, 1906.

To /LZZ wtont t 771.001/ concern:

Be it known that we, l/VALTER B. PEAR- soN, a resident of Detroit, Wayne county, Michigan, and CHARLES E. ROBERTS, a resident of Oak Park, Cook county, Illinois, citi- Zens of the United States, have invented certain new and useful Improvements in Screw- Machines, of which the following is a complete specification.

This invention relates to screw-machines, and particularly to machines for making metal screws, such as set-screws and capscrews, being a division of our prior application, Serial No. 106,620, filed May 9, 1902.

The primary Object of the invention is to provide a screw-machine which will effect a saving in the material from which the screw is made and in the time of making the screw.

To avoid waste of stock in severing blanks, the invention consists of means for partially severing the blank from the bar of stock by cutting a V-shaped groove in the bar of stock at the desired point of severance and thereafter turning the bar of stock upon its axis while employing means to operate upon one end of said bar of stock to change the speed of rotation of that end relatively to the other end.

The process itself of severing blanks from a bar of stock, consisting in first partially severing the blank from the stock by grooving said bar at the desired point of severance, the groove of the bar being angular or V-shaped, and then turning the sections of said bar upon their common aXis relatively to each other, has been mentioned in Patent No. 732,218, dated June 30, 1903, and issued to us as patentees.

The machine we describe herein discloses mechanism for turning the bar of stock on its aXis until it reaches a position where the cutting-tool operates on it, and during its continued rotation the cutting-tool partially severs the bar of stock. A substantial part of the diameter of the bar lof stock is left uncut, and in actual practice by means of the V-shaped cutting-knife we sever only about one-half the diameter, thereby causing a considerable saving in material and time. Means are then provided for engaging the end of the partially-severed stock, and by retarding the subsequent rotation of the bar of stock on one side of the point one end of the stock is twisted off from the bar of stock. In the preferred form of construction which we have illustrated there is shown means for stopping the turning of the bar of stock after it is partially severed until holding means have engaged the end of the bar of stock to hold it against further rotation. When the bar of stock is subsequently rotated and the end near the point of severance is held, the end of the stock is twisted. In the machine disclosed the bar of stock is completely stopped from rotary movement before the holding means operates, and as it may be possible to engage the end of the stock while being rotated we therefore do not desire to limit ourselves to this particular form of mechanism.

1n the draw'ngs, Figure 1 is a side elevation view of our machine. Fig. 2 is a transverse sectional view along theline 5 5 of Fig. 1. Fig. 3 is a longitudinal sectional view between the points indicated by 5EL .and 5b in Fig. 1. Fig. 4 is a vertical section through the part of the machine to the left of the line 14 in Fig. 1. Figs. 5 and 6 are detail views of parts of the stopping mechanism. Figs. 7, 8, and 9 are detail views of parts of the machine.

Like characters of reference indicate like parts in the different views.

The frame of the machine consists of a bed A, Fig. 1, supported on posts or pillars A,

which extend upwardly from the base A2, the sides and bottom of which are inclosed, having a downwardly-projecting fiange around the upper edge, thus forming a pan adapted to receive the oil which runs Off the tools and chips formed thereby.

The operating parts of the machine are driven from a transverse shaft B, Figs. 1 and 4, and a longitudinal shaft C, of which the shaft B is driven from a suitable source of power by means of a belt (not shown) applied to the driving-pulley 1, secured to said shaft. The shaft O is driven by means of a suitable .driving connection with the shaft B. We

connection may be made between the trans- IOO verse shaft B and the longitudinal shaft C. As indicated, there is secured to said shaft B a gear (L, which gears with an intermediate gear (L2, revolubly mounted on a stud (L0, supported by the frame A of the machine. This gear is connected with a smaller gear (L4, which gears with a large gear-Wheel (L0,- connested to the transverse shaft D, which eX- tends below the shaft B. The shaft D is formed near its center with a worm=gear (L0, which meshes with a gear formed on a drum (L7, secured to the shaft C, which shaft is located near the bottom of the machine.

yThe stock-spindle of the machine is indicated by F. This stock-spindle is secured to its bearings (see Figs. l and 3) by means of nuts (L8 threaded thereto, hardened-steel washers (L being inserted between said nuts and the ends of the bearing-boxes of said spindle. In the preferable construction shown said nuts (L2 are threaded directly to the bodies of said spindles, said nuts being split to provide for engaging them with the threads on said spindles, the sections thereof being secured together by clamping-screws (L10. Said screws (L10 also provide convenient means for clamping said nuts in any desired longitudinal adjustment on said spindles.

The stock-spindle F, Figs. 2 and 3, is hollow, and the bar of stock of angular shape (partially shown at (L11, Fig. 2) is delivered to the machine therethrough by means of a wire-feed which, as regards its general features, is of a familiar type, comprising a feedtube (L12 and spring-jaws (L13 on the front end of said feed-tube adapted to grip the bar of stock with sufficient force to impart movement thereto with said feed-tube, and said bar of stock is free to move therewith. The stock-spindle F is also provided with a stockchuck adapted to secure the bar of stock therein against movement. As shown, said chuck is of the type comprising a chuck-body (L14, secured to the ends of the spindle, and a split collet (L15, preferably secured against rotation relatively to the chuck-body (L14 by a key (L10, a plunger (L17, a butt-ring (L10,'Fig. 2, secured to the rear end of said plunger, belllevers (L10, pivoted in a collar @L20 on the stockspindle, the short arms of which bear against the rear end of the butt-ring (L18 and a wedge (L22, which is longitudinally movable on the stock-spindle and is adapted to force the long arms of the bell-levers (L10 outwardly and thereby force the plunger (L17 forward, which will in turn force the chuck-collet (L15 into the taper of the chuck-ring (L12 and clamp said collet upon the bar of stock. T o facilitate changing the chuck-bodies and to insure register of the opening therein with the holding mechanism hereinafter mentioned, said chuck-body (L14 instead of being threaded to the end of the stock-spindleis bolted to a ring (L21, Fig. 3, threaded to the end of said spindle in fixed adjustment. If the length of Sams@ the chuck-'body (L11 is varied,- the length of the chuck-collet (L15 will also have to be varied correspondingly.

Movement longitudinally of the spindle F to lock and release the bell-levers (L10 at de sired predetermined intervals is imparted to the wedge (L22 by means of a lever (L23 in the following manner, (see Figs. 2 and 7 z) The lever (L20 is pivoted upon an extension in the bearing-box of the shaft D. Formed on the upper end of said lever is a yoke (L21, secured in which are pins (L25, the inner ends of which engage a groove (L20, formed in the surface of said wedge (L22. Secured to the lower end of said lever (L23 is a lateral projection (L27, which engages a cam formed on the drum (L7, adapted to impart movement to said lever (L20, and thus to the wedge (L22 in opposite directions in the desired manner.

Instead of being rigidly secured to the spindle F the collar (L20is supported in yielding adjustment thereon in the following manner, (see Fig. 2:) Threaded to said spindle F in the rear of said collar (L20 is a ring (L20, in which are mounted spring-plungers (L00, the forward ends of which project beyond the face of said ring and abut against the rear face of the collar (L22. As shown, said plungers (L00 are fitted to and are longitudinally movable in holes or sockets (L01, formed in said ring (L20, and coiled springs (L02 are inserted between the heads of said plungers and the rear ends of said holes or sockets surrounding the shanks of said plungers as guides. As shown also, the rear ends of the shanks of said plungers (L20 project through holes or openings in the rear side of said ring (L20, and secured thereto are washers (L00, which limit the movement of said plungers under the infiuence of the springs (L02. The springs (L02 are sufficiently strong to insure the desired operation of the bell-levers (L10 and adjunctive parts under normal conditions. If, however, excessive resistance is offered to the movement of the parts actuated by the bell-levers (L10, as should Ythe bar` of stock run uneven, being larger in some parts than in others, or should chips become lodged between the engaging surfaces `of the chuck-body (L11 and of the chuck-collet (L15, either of which might prevent the desired operation of the machine or might even subj ect parts thereof to a strain which would break them, said-springs will be compressed, allowing the machine to go through a regular cycle without undue strain on any of its parts and without blocking the machine.

The relation and adjustment of parts are such that the chuck-collet (L15 will be closed when the feed-tube (L12 is retracted and will be open when the feed-tube is advanced. The bar of stock will thus be held against rearward movement with said feed-tube and will bel fed forward by and with said feed-tube.v In the preferable construction shown also spring-jaws (L02, Fig. 2, `substantially like and IOO ITO

ISO

adapted to grip the bar of stock in the same manner as the @13 on the forward end of the feed tube @13, are secured to the rear end of said feed-tube. Thesel jaws are for the purpose of feeding the bar of stock before it reaches said jaws @13, thus providing for starting a bar of stock into the machine as soon as the rear end of the bar on which the machine is operating passes said aws @34.

The rearward extension @33 on the machineframe preferably consists of a bracket removably secured thereto. As shown, Fig. 4, said bracket is secured in position on the bed of the machine-frame in the following manner: Formed on the forward end of said bracket is a circular projection @30, at the base of which is a shoulder @37. The projection @30 is fitted to an opening @33, formed in the bridge M on the frame A, and said projection is firmly secured in said hole or opening @38 by means ofa bolt @30, threaded into the end of said bracket, the head of which bears against a plate @40, which extends across the opening @38 on the front side of the bridge M. Between its ends said bracket @33 rests upon the bed A and is rigidly secured thereto by means of a bolt @41.

' The plunger @17 is connected to the stockspindle F, so as to rotate therewith, by means of the bell-levers @13, (see Fig. 2,) the short arms of which extend through slots @42 in said stock-spindle and engage slots @43, formed in the rear end of the butt-ring @13. The feedtube @13Ais connected to the stock-spindle F, so as to rotate therewith, by means of keys @44, secured to said stock-spindle, which engage grooves @43, formed longitudinally in the feed-tube.

The feed-tube @12 may be reciprocated to feed the bar of stock by any suitable means. As shown, Fig. 2, said tube is revolubly se cured against longitudinal movement in an arm @40 on a slide or saddle @47, fitted to and longitudinally movable on suitable guides or ways formed on the brackets @33. As shown, the bearing for said feed-tube in said arm @40 is formed 'in a bushing @43, secured in said arm @4, the arm @40 being split at the outer side of the opening therein to receive said bushing and being adapted to be clamped upon said bushing by means of a clampingscrew @40. As shown also, said feedtube is secured in fixed longitudinal adjustment in said bushing'by means of nuts @30, threaded to said feed-tube on opposite sides of said bushing. As shown also, ball-bearings are provided on both sides of said bushing. As shown, said ball-bearings consist of rings @31, which bear against the sides of said bushing, in which are formed V-shaped ball-races @33. The balls @33 are confined in said ball-races @32 by means of disks @34, adapted to be forced against said balls with desired pressure by means of nuts @30, which bear against the outer sides thereof. A Preferably, also, thimbles @33 inclose the members of said ball-bear.

ings at their edges, said thimbles being snugly fitted to the rings @31, whereby said thimbles @33 will be secured in position and being loosely fitted to the disks @34 to allow said disks to rotate freely with the feed-tube.

Revolubly mounted in a suitable bearing in the bracket, Fig. 4, is a stub-shaft @30, to the upper end of which is secured a disk @37, which is connected to the slide or saddle @47 by means of a connecting-link @33, one end of which is pivoted to the disk @37 eccentrically to its aXis of rotation and the opposite end of which is pivoted to the slide or saddle @47. With this construction it is obvious that rotation of the disk @37 will impart a reciprocating movement to the slide or saddle @47 and that the eccentricity of the .point of attachment of the link @33 to said disk @37 will determine the travel of said slide or saddle, and thus the feeding of stock to the machine. As preferably constructed, means are provided for changing the feed of the machine by varying the eccentricity of the point of attachment of the connecting-link @33 to the disk @37. As shown, this is effected in the following manner: Secured to the connecting-link @33 are pins @30 and @00, of which the pin @30 is interchangeable in a series of holes @01, Fig. 2, formed in the disk @37 at different distances from its aXis of rotation, and the pin @00 is interchangeable in a series of holes @02, formed in the saddle @47, the holes @03 in the saddle being preferably formed in a plate @03, re-I movably secured in said slide or saddle, (see Fig. 4,) thus providing for hardening said plate. The pins @39 and @00 are secured in engagement with the holes which they respectively engage by means of a spring-pressed shoe @04, supported in a bar @03, which passes over said connecting-link @33. As shown, Fig. 2, the' bar @03 is hinged to the bracket @33 at one side of said connecting rod or link and is bolted to said bracket @33 at the other side of said connecting rod or link, thus making provision for quickly removing the bar when ,it is desired to change the feed of the machine. As shown also, the shoe @04 is maintained in position in the bar @03 against the pressure of the spring applied thereto by means of a nut @00, threaded to the projecting end of the shank @07 of said shoe. Intermittent rotary motion through one hundred and eighty degrees is imparted to the stub-shaft @30 and to the disk @37, carried thereon, in the following manner: Formed on or secured to the lower end of said stub-shaft @30 is a bevel-gear @00, Fig. 4, which is adapted to be engaged by segmental gears @100 on the shaft C, the relation of parts being such that each of said segmental gears will rotate said bevel-gear @08 through one hundred and eighty degrees, or one-half of a revolution, and will leave the teeth of said bevel-gear @03 in proper position to be engaged by the teeth of the following IIS segmental gear @'33, As heretofore explained, however, when it is desired to reset the machine to make a longer or shorter screw than that which it is making at a given time the feed must be varied in such manner that the blank, long or short, will be fed to the same point through the stock-spindle; but when the pin a3 is changed from one hole L61 to another the travel of the saddle c will be varied symmetrically on both sides of a central point. Thus to bring said slide or saddle to the same forward limit of travel it will be necessary to change vthe pin e30 from the hole C032 with which it is in engagement at the time to one farther forward when it is desired to increase the feed or to one farther back when it is desired to decrease the feed. As shown, there are ten holes @31 in the disk 0,57 and only five in the saddle a, the holes in said slide or saddle corres onding to alternate holes insaid crank or disk. This is due to the fact that with desired fineness of feed the holes 0,32 in said saddle would run into each other if a hole (L32 were provided for each hole e111. In practice, therefore, we have used two bars @38 of different lengths, one of said bars being longer than the other by an amount equal to one-half the distance between the adjacent holes (2)12.

As shown, the segmental gears 0,12 are formed on plates or arms 0,21*, the inner ends of which are fitted to a circular shoulder formed on the drum a7 and which are secured to said drum by means of bolts a", which engage a T-slot formed in said drum. Provision is thus made for adjusting said segmental gears circumferentially of the shaft C to vary the times of actuating the stub-shaft a3 and the parts controlled thereby to cause the same to work in desired relation to other parts operating in combination therewith.

Rotary movement is imparted to the stockspindle F in the following manner, (see Figs. 1 and 3:) Revolubly mounted in the bridges M and N of the machine-frame there is a shaft Q, which is driven directly from the shaft 'B by means of bevel-gears Z2/ and Z22, rigidly secured to the shafts B and Q, respectively. Relatively large and small back gears or pinions Z23 and Z21 on the shaft Q respectively engage relatively small and large gears Z23 and Z2, loosely mounted on the stock-spindle F, which are adapted to be secured to said spindle at desired predetermined intervals, preferably by means of suitable clutches. As shown, the gear Z20 is adapted to be secured to said shaft by means of afriction-clutch, (indicated as a whole by R.) The gear Z25 is adapted to be secured to said stock-spindle F by means of clutch-teeth Z27, Fig. 3, thereon, which are adapted to be engaged by corresponding clutch-teeth Z233, formed on a sleeve Z212, Figs. l and 3, splined to said stock-spindle. As shown, the sleeve Z23 is mounted between the gear Z23 and the clutch'R, and the senese wedge which controls said clutch R is formed on said sleeve, the relation and adjustment of parts being such that movement of said sleeve to lock the clutch will 'disengage the clutch-teeth Z27 and Z23, and vice versa,and such also that during a portion of the travel of said sleeve both clutches will be disengaged from said stock-spindle. Movement longitudinally of the stock-spindle is imparted to the sleeve Z211 to secure the gears Z25 and Z2G to said stock-spindle and to release said gears therefrom by means of a lever Z210, pivoted upon the machine-frame, Fig. 3, a projection Z211 on the upper end of which engages `a groove Z212, formed in said sleeve Z23. Formed 0n the lower end of the lever Z210, Fig. l, is a cam-surface comprising sections Z213 and Z211, of which the section Z213 is substantially concentric with the pivotal axis of said lever and the section Z211 is upwardly inclined. Pivoted at one end upon the machine-frame is a lever Z213, Fig. l, having a pin Z213, which is held yieldingly in engagement with the cam-surfaces Z213 and Z214 by means of a spring Z217, (in dotted lines,) applied to the free end of said lever Z215. With this construction it is obvious that when the pin or stud Z216 is in engagement with the cam-surface Z213 the lever Z215 will be unaffected thereby, and when in engagement with the cam-surface Z214 the tension of the spring Z217 will tend to throw the lever to effect engagement of the clutch-teeth Z27 Z2S, and thus to secure the slow-driving gear Z25 to the stock-spindle. The strength of the spring Z217 is such that when the sleeve Z29 is free to move under its influence it will throw said sleeve to effect engagement of the clutchteeth 127 Z28. The relation of parts is such that when the sleeve Z22 is in position to lock the clutch R the pin Z21G will be in engagement with the cam-surface Z213.

The cam-surfaces Z213 Z211 are referably formed on a hardened-steel plate 18, Fig. 5, secured to the end of the lever Z213.

Pivotal movement is imparted to the lever Z210 to lock and disengage the clutch R at desired predetermined intervals by` means of suitable surfaces on a cam Z212 on the shaft C, which are adapted to engage a stud Z220, se-

` cured in the lower end of said lever Z210, said stud being preferably provided with an antifriction-roller.

In order that the screw-blank carried on the end of the bar of stock may be stationary when the chuck-jaws, hereinafter to be described, are closed upon the same, means are provided for stopping the stock-spindle at the time said chuck-jaws are closed and in proper position for the chuck-jaws to grasp the same in the desired manner. As shown, the means for so stopping said spindle are as follows, (see Figs. l and 6:) Formed in the sleeve Z23 are stop-slots Z221, which are adapted to be engaged by a pin or projection Z222, which projects inwardlyfrom a lever Z223, piv- IIC IIS

oted upon the machine-frame, the opposite end of which projects into the path of travel of a cam 621 on the shaft C, a spring 623 applied to said lever being adapted to move the lever 623 pivotally to effect engagement ofthe pin 622 with the stop-slots 621. As shown, the lever 623 has a hardened-steel shoe 626 secured to its free end, which is provided with a tongue or projection 627, which engages the cam-surface on the cam 621.

During all of the time that the clutch R is locked and during most of the time that the clutch-teeth 67 68 are in engagement the tongue or projection 627 on the lever 623 rides on a substantially cylindrical section of the cam 624, in which position the pin 622 will be held out of engagement with the slots 621 and the stock-spindle F will be free to rotate. When it is desired to stop said stock-spindle, however, the tongue or projection 627 dropsI into a recess or notch 623 in said cam 624, thus allowing the spring 623'to move the lever 623 pivotallyu to effect engagement ofthe pin 622 with one of the slots 621, the position of said recess or notch 623 and its dimension circumferentially of the cam 624 being such that the stock-spindle will be held stationary during the time that the blank-supporting chuckr are being closed. Secured to the sides of the notch or recess 628 are hardened-steel plates 623 630, which receive the wear due to the action of the tongue or projection 627. The relationof parts is such also that the stockspindle F will be stopped almost immediately after the sleeve 63 has been moved to disengage the clutch R and to effec-t engagement of the clutch-teeth 67 63, which form an effective brake adapted to check the speed of said stock-spindle, aseach time the teeth 6B on the sleeve 69 run over77 the teeth 67 on the gear 65 it will necessitate stretching the spring 617 through the medium of the projection 613 on the lever 615 acting on the cam 614. Before stopping said stock-spindle F it will thus be necessary to disengage the clutch-teeth 67 63. In the preferable construction shown this is effected by forming the slots 621 on an incline toward said teeth and disposing the pin or stud 622 so that it will engage said 'slots adjacent to their vforward ends, the relation being such that said pin or stud 622, acting on the inclined front side of the slot 621, which it engages, will move the sleeve 69 longitudinally of the stock-spindle to disengage the clutch-teeth 67 63 before said pin or stud reaches the end of said slot 621. A great advantage of throwing the clutch-teeth 67 68 into engagement when the clutch 69 is disengaged and before stopping the stock-spindle is that said stock-spindle will be positively rotated at a slower speed until it reaches the position in which it is designed to be stopped by the pin or stud 622-that is, with the opening in the chuck-collet L15 in register with the blank-supporting jaws without relying on the momentum of said stockspindle, which might not always operate as intended. The relation and adjustment of parts are such also that during the time the stock-spindle is heldlstationary by the pin or stud 622 the lstud or projection 613 on the lever 615 will bear on the inclined cam-surface 614 on the lever 610. Thus as soon as the pin or stud 622 is disengaged from said slot 621 the spring 617 will at once throw the clutch-teeth 67 68'into engagement and rotate the stockspindle positively at its slow speed and with great power, thereby twisting a blank which has been previously partially severed from the bar of stock off from said bar of stock.

In order to eliminate as much as possible the noise caused by the clutch-teeth 67 68 running over each other, we prefer to provide means independent of said clutch-teeth for braking or checking the speed of the stock-spindle when the clutch R is disengaged. In the preferable construction shown said means consist of an arm 631 on the lever 623, which extends up on the rear side of the stock-spindle F. Secured in said arm is a plug 632, of hard wood or other suitable material. gaged pivotal movement is imparted to the lever 623 to advance said plug 632 into engagement with the surface of the sleeve 63 with sufficient pressure to brake or check the stock-spindle. As shown, this is accomplished by providing a projection 633 on the surface of the cam 621, which will engage the projection 627 on the lever 623 just before said projection 627 drops into the notch or recess 623, the height of said projection 633 being such that the lever 623 will be moved pivotally thereby sufficiently to depress the plug 632 into frictional engagement with the surface of said sleeve 69 in the desired manner.`

A convenient manner, vas shown, for forming the projection 633 consists in extending the plate 63, secured to a side of the notch ,or recess 623, above the cylindrical section of the cam 622. In the preferable construction shown also the plug 632 is adapted to be adjusted outwardly by means of a screw 631, threaded into the lever-arm 631, which bears against the end of said plug.

The screw-blanks are necked between the head and the body thereof and are partially severed from the bar of stock while in the stock-spindle F by suitable tools which are fed toward and from the bar of stock in any desired manner. As shown, the tool which partially severs the screw-blanks from the bar of stock is adapted to rough-point one screw-blank and to face off the end and finish the head of the neXt succeeding screw-blank. In the preferable construction shown, Figs. 3 and 8, the neeking-tool c and the cut-off tool c2 are secured in a tool-holder c3, so as to be adjustable toward and from the bar of stock. The tool-holder is supported upon Just before the clutch R is disen-' IOO IIO

the upper end of a lever c, pivoted between its ends upon a bar c5, secured against rotation to the machine-frame in proper position. The tool-holder c3 is preferably secured to the lever c4 by means of bolts c6, the heads of which engage T-slots c7, formed in said lever in a familiar manner. Provision is thus made for` adjusting the tools longitudinally of a bar .of stock supported in the stock-spindle F. The tools c c2 are maintained normally retracted from the bar of stock by means of a spring cs, applied to the lower end of the lever c4, one end of which is secured to a pin in said lever and the oppo` site end of which in an eyebolt secured in the machine-frame or other rigid support.`

Movement of the lever c4 under the infiuence of the spring c8 may be limited by means of a suitable stop. Pivotal movement is im. parted to the lever cAx to feed the tools c c2 into the bar of stock by means of cams c10 c11 on the shaft C.

The operative surfaces of the cams 01 c being separated by intervening spaces, as shown, it is obvious that the tools c c2 will be fed toward and retracted from the bar of stock twice during .each revolution of the shaft C, the cam c, being the lower, operating to neck and partially sever the screwblank from the bar of stock and the cam c1", being the higher, operating tovfinish or face off the ends of the screw-heads. During one of the intervals in which the lever c4 is out of engagement with said cams 010 c11 the screw-blank is twisted off from the bar of stock at the point of partial severance therefrom in a manner hereinafter to be described, and during the other interval when said lever is out of engagement with said cams the bar of stock is fed forward. v

The head (indicated as a whole by V) on which the screw-blanks are supported during the operation of the machine is rigidly secured to a shaft W, revolubly mounted in suitable bearings .in the machine-frame. Chuck-jaws d, Fig. l, are supported by said head V and are adapted to grip the heads of the screw-blanks delivered through the stock-spindle F. As shown, the chuckejaws d are formed on levers d2, pivoted in the head V, there being a plurality of sets of chuck-jaws. As shown in Fig. l, when there is a set of chuck-jaws in position for receiving the blank from the stock-spindle F there is a corresponding set of chuck-jaws opposite the tool J carried on the tool-spindle The specific arrangement of the chuck-jaws and the operation of same are fully described in our divisional application, Serial No. 229,035, for wedges.

The chuck-jaws are normally open and maintained open by springs or by the weight of the free ends of the levers d2. They are of angular shape, adapted to be closed to grip the screw-blanks by wedges d3, fitted to and longitudinally movable on the Shanks d4 as guides, which wedges are adapted to separate the ends of the levers d2 opposite vto those on which said chuck-jaws are carried, thereby closing said chuck-jaws in the desired manner. These chuck-jaws are moved up to proper position for grasping the blanks. The jaws during the time the blank is held prior to its complete severance remain stationary and hold one end of said blanks immovable after the sides of said blanks are firmly grasped by said jaws.

Reciprocating movement toward and from the tools is imparted to the head V through the agency of the disk or head X, provided with radial projections d5, prefeably provided with antifriction-rollers, which engage a camway d6, formed on the drum (Z7, rigidly secured to the shaft C. The disk X may be secured in any usual manner to said shaft W, it being necessary that it be secured to said shaft without relative longitudinal movement.

Intermittent rotary movement is'imparted to the shaft VV, and thus to the head V, through the agency of the disk d8, revolubly mounted upon a stud d", secured in the end of the machine-frame. The pin dy, Fig. 9, secured in said disk ds, is adapted to engage radial slots du, formed in projections from the head X. The head X may be called the "indexing-head and the disk d8 the Hconverter. Secured to said converter d8, so as to rotate therewith, is a gear dx, the teeth of which are adapted to be engaged by a segmental gear d on the drum (Z7. The segmental gear is adapted to engage gear dx to rotate the shaft W and the parts carried thereon when said shaft is at the rearward limit of its movement, thus insuring that the screw-blanks carried in the chuck-jaws d will be fully retracted from the tools. We have shown formed on said shaft W a ring d, which, in cooperation with a bearingboX d for said shaft W, obviously will hold said shaft against too great endwise movement, thereby preventing the projections d5 being thrown out of register with the camways de( Movement is imparted to the wedges d3 to close and open the chuck-jaws d at desired TOO IOS

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predetermined times in the following manv ner, Fig. l Pivoted upon the machine-frame is a lever d, (shown in dotted lincs,) one end of which extends upwardly on the side of a head d1 remote from said wedges d3 when the chuck-jaws are in register with the stockspindle F, said jaws being open to receive the screw-blank from said stock-spindle F. A. pin d on the lower end of the lever d engages a camway d18 on a drum d1, rigidly secured to the shaft C. The upper end of said lever (115 will be out of contact with the head d1 while said head V is being moved toward the tools by the cam, the shape of the cam d being such, preferably, that the upper end of the lever d15 will strike the head d1 and move the same so as to force the wedge d2, carried thereby, between the ends of the lever d2, thus closing the chuck-jaws just at the time the head V is in position of nearest approach to the spindle F and Q. The relation of parts is such also that the lever 523 will be moved pivotally to bring the pin 522, carried therein, into engagement with a slot 521 in the sleeve 5J onthe stock-spindle F to stop said stockspindle just before the chuck-jaws are closed.

The purpose and operation of the shoe aM and its associated parts are fully explained in our divisional application for mechanism for feeding a bar of stock, as also are the purpose and function of the holes am.

The relation of parts might be such that the chuck-jaws would not be closed until after the stock-spindle had been stopped, and just as said stock-spindle was being started by the slow gear 54 55 the said chuck-jaws could be closed, operating thereby to retard or check the rotation of the end of the stock engaged thereby. The relation, as shown, is such that when the stock-spindle F is held stationary by the pin 522 in engagement with the slot 521 the opening in the chuck-collet al, and thus the screw-blank on the end of a bar of stock secured therein, will register with the chuck-jaws d when closed, so that said jaws will grip the head of said screw-blank in the desired manner.

-The general operation of our machine is as follows: Beginning immediately after the severing of a blank, at which time the blankcarrying head is fully advanced and the stockspindle rotating at its slow speed, the sequence of operation is as follows: Immediately after a blank is severed the Jfast drivinggear is thrown into train with the stock-spindle, causing it to rotate at high speed. The blank-carrying head is retracted and indexed,

. and at the same time the severing-tool is fed forward to finish the end of the head, and the necking-tool passes over the screw-blank between the head and body, thus finishing the neck. After the severing and necking tools are retracted and the previously-severed blank is out of the way the bar of stock is fed forward with the stock-spindle still rotating at its high speed. The severing (and necking) tools are then fed forward to partially sever a blank and to rough out the neck and again retracted, immediately after which the fast driving-gear is thrown out of train with the stock-spindle and the clutch of the slow driving-train thrown in, which, as heretofore explained, will operate to brake the stockspindle and reduce its speed. The lever 523 is then moved pivotally to cause the pin 522 therein to engage one of the cam-slots 521 in the sleeve 5, whereby the clutch-teeth 57 58 will first be disengaged and then the spindle stopped. In the meantime the blank-carrying head has been advanced with .a pair of empty chuck-jaws in register with the screwblank in the stock-spindle and into position to grip the head of the partially-severed screw-blank on the bar of stock. Immediately after the stock-spindle is stopped the chuck-jaws opposite the blank are closed upon the head of the partially-severed screwblank, after which the pin 522 is withdrawn from the slot 521 to release the stock-spindle and the clutch-teeth 57 58 thrown into engagement, causing the stock-spindle to rotate at its slow speed, which will twist off the artially-severed blank, the head of Whic is held in the clutch-jaws on the blank-carrying head, thus severing the blank. The sleeve 5 is then moved longitudinally of the stockspindle to disengage the clutch-teeth 57 58 and to lock the clutch R, causing the stockspindle to rotate at its fast speed.

Having thus described ourinvention, we claim y l. In a screw-machine, the combination of a revoluble stock-holder and means for rotating'the same, a cutting device for partially severing a bar of stock secured in said revoluble stock-holder, a second stock-holder for seizing the end of said partially-severed bar of stock and holding the same stationary, means for intermittently stopping said revoluble stock-holder, and means to cause said second stock-holder t0 grasp the end of said partially-severed bar of stock when said revoluble stock-holder is in positions o f rest, substantially as described.

2. In a screw-machine, a revoluble stock-holder and means for rotating the same at relatively fast and slow speeds, a cutting device for partially severing a bar of stock secured in said revoluble stockholder, a second stock-holder for seizing the end of said partially-severed bar of stock and holding the same stationary, means for intermittently stopping said revoluble stockholder, and means to cause said second stockholder to grasp the -end of said partially-severed bar of stock when said revoluble stockholder is in positions of rest, substantiallyas described.

3. ln a screw-machine, the combination of a stock-spindle, a movable holding device adapted to be brought into register with said stock-spindle to seize one end of the bar of stock, a cutting device for partially severing a bar of stock secured in said stock-spindle, mechanism for rotatinoa said stock-spindle, means for intermittentljy stopping the rotation of said stock-spindle, and means to cause the holding device to approach and seize the stock during intervals of rest of the stock-spindle, substantially as described.

4. In a screw-machine, means for rotating a bar of stock, a change-of-speed device for IOO the combination of les said rotating means, a cutting device for partially severing said stock, means for holding stationary one end of said bar, means to operate the change-of-speed device whereby there will be a change from fast to slow speed, and then to inoperative position before the end of the bar is seized by the holding device,l

means for operating the change-of-speed device subsequent thereto and after the partial 1severance of said stock, for the purpose speci- 5. In a screw-machine, a main operating device, a stock-spindle and a stock-holder connected therewith for an annular bar of stock, a clutch for connecting said operating device with said spindle, a stop device for said clutch and spindle, and a second stockholder adapted to cooperate with said angular bar, when at rest for clamping samek to said stock-holder, means for operating said stop device arranged rst to disengage said clutch from said operating device, and im- .mediately thereafter hold said clutch and spindle stationary in proper predetermined position to insure the proper registery of the second holding device and bar of stock, and subsequently to release said stop device, and means for eecting rengagement of said clutch for the its axis.

6. In a screw-machine, a main operating device, a stock-spindle and a stock-holder for an angular-shaped bar of stock, a clutch for connecting the operating device with said spindle for rotating same, a stop device for said spindle, a second stock-holder, angularshaped jaws thereon, means for moving the stop device to disengage said clutch from the main operating device and hold said bar of stock and said spindle at 'a predetermined point of rotation, means for operating the jaws of the second stock-holder while said spindle is held by said stop device, and means for releasing said stop device subsequent to the operation of said jaws, for the purpose specified.

In testimony that we claim the foregoing as our invention we aHiX our signatures, in presence of two subscribing witnesses, this 7th day of September, A. D. 1903.

WALTER B. PEARSON. CHARLES E. ROBERTS.

Witnesses:

M. P. FURR, K. A. COSTELLO.

purpose of twisting the bar on

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