US232869A - w orsley - Google Patents

Description

4 Sheets--Sheet .1. s. L; WORSLEY.

Machine for Threading Screws No. 232,869. Patented Oct. 5,1880.

N-PETERS, FNOTO-UTNOGRAFHER, WASHINGTON, 0 c.

2 t O m 8 m m 5 e e I h .T. S .C W e m n u e You En im & R6 or Wh T u 2 86 H 1 1H 0 a M MPETENB. PHOTO-UTHOGRAPHER, WASHINGTON D C S. L. WORSLEY.

Machine for Threading Screws. New 332,869. Patemed Oct. 5, i880.

4 Sheets--Sheet 4.

s. L. WORSLEY. Machine for Threading Screws. NO. 232,869.

Patented Oct. 5,1880.

N. PErFJlS, PHOTO-LITNDGRAPMER WASHINGTON, D. C.

UNiTED STATES PATENT prion.

SAMUEL L. WVORSLEY, OF BUFFALO, NEW YORK, ASSIGNOR TO P'LUMB, BURDIOT & BARNARD, OF SAME PLACE.

MACHlNE FOR THREADING SCREWS.

SPECIFICATION forming part of Letters Patent No. 232,869, dated October 5, 1880.

' Application filed March 1, 1879.

To all whom it may concern Be it known that I, SAMUEL LORD WORS- LEY, of Buii'alo,in the county of Erie and State of New York, have made a new and useful invention of Improvements in Machinery for Screwin g or for Threading Bolts, some of which are applicable to oth er purposes; and I do hereby declare that the following is a full,clear, and exact description and specification of the same. i

The principal object of the invention is to take bolts automatically, one at a time, from a bolt-holder, to cut screw-threads upon their stems, and to discharge them from the machine. The cutting of the screw-threads, commonly called the screwing or threading of the bolt, is effected by holding it stationary while a screw-die is simultaneously revolved and advanced upon the bolt-point; and after the screw-thread is out to the requisite extent the revolution of the serew-die is reversed so as to back it off the bolt-point. Hence the screw-die is caused to revolve in alternately opposite directions, and the duration of the period of direct movement previous to reversal determines the extent of the screw thread formed upon the bolt-stem. It is, however, expedient that the same machine should be capable of being used to cut screw-threads of different extents upon bolts; and to this end the object of some of the improvements hereinafter described is to vary the periods of reversal of the movement of the revolving shaft or mandrel carrying the screw-die as required to form screw-threads of different exteuts that is, screw-threads making different number of turns around the bolt-stems.

The said improvements consist of various combinations of devices, of which devices the following are the principal, viz: Gripers or jaws by means of which the bolt-blank is held stationary during the threading or cutting of the screw-thread upon its stem; a die holder or chuck by which the screw-die is held and moved; a revolving sliding mandrel by which the die'holder and die are turned and caused to advance against the bolt-blank so as to cut the screw-thread thereon 5 revolving gearing by which the mandrel is caused to revolve in either of two directions reversing-gearing by means of which the direction in which the mandrel is caused to revolve is reversed; a leading-cam, or some equivalent or substitute therefor, to commence the advance of the screw-die upon the bolt-blank, or vice versa; variablepawl change gearing by means of which the times at which the reversing-gear reverses the direction of movement of the re volving mandrel can be varied without necessari] y removing parts of the machine and substitutingothers in their places, and without dependence upon the longitudinal movement of either the die-holder or the gripers which hold the blank to be threaded; a bolt-holder in which bolt-blanks ready for screwing or threading are held; a bolt-mover by means of which the bolt-blanks are taken one at a time from the bolt-holder; one or more stops by which the descent of bolt-blanks in the boltholder is checked when the lowest bolt-blank is to be taken by the bolt-mover; transfer fingers or mechanism by means of which a boltblank is transferred from the bolt-mover to the gripers or jaws by which the boltblanl; is held during screwing or threading.

Sundry minor devices, hereinafter particularly described, are also employed in making some of the combinations claimed as the invention. The said devices are combined by combining mechanism the construction and character of which can be vagied as circumstances render expedient, or to suit the views of different constructors.

In order that the invention may be fully understood, I have represented in the accompanying drawings, and will proceed to describe, the principal parts of a bolt-threading machine embodying my improvements in the best form in which they have been embodied at this date.

Figure 1 of said drawings represents a plan of the said machine. Fig. 2 represents a front elevation of the same. Fig. 3 represents an end view of the same. Fig. 4 represents a transverse section of the machine at the line 00 x of Fig. 1. section of the machine at the line 3 3,! of Fi 1. In some of said figures certain parts are omitted for perspicuity. Figs. 6 to 16 represent views of detached parts of the machine, desig nated by the same letters as the same parts Fig. 5 represents a transverse 5 9 esasce are designated by in the other figures, and some of said parts being represented upon a larger scale than in the other figures.

The working parts of said machine are connected with a strong frame, A, and all the moving parts derive their motion from a drivin g-shaft, B, which is held in suitable bear ings of that frame, and is fitted with a beltpulley, O, to which the driving-beltis applied.

In practice it is coiwenient either to apply a movable tigh tening-pulley to the driving-belt, so that the latter can be slacked and the machine stopped by moving the tightening-pulley, or to apply a loose pulley to the drivingshaft, and to employ a belt-shipper to transfer the belt to and from the driving-pulley and this loose pulley.

The driving-shaft B is connected, by means of coggearing, hereinafter more particularly described, with a counter-shaft, B, a clutchshaft, B and a revolving hub, B the last being mounted upon a cam-shaft, B

The bolt-blank to be screwed or threaded is held during threading between a pair of gripers or jaws, D D, which grasp its shoulder beneath the bolt-heads and hold the bolt-blank stationary, or so that itcannotrevolve. Then a square or angular shouldered bolt-blank is to be threaded the adjacent faces of the jaws are constructed with angular grooves fitting the angular shoulders of the bolt-blanks.

The screw-die by which the screw-thread is cut is held by a die-chuck, E, which is secured to the mandrel F. This mandrel is connected by cog-wheels a a with the clutch-shaft B and is also supported in boxes I) b, which permit it to revolve and to slide endwise toward and from the jaws D D. The axis of this mandrel and the axial line of the opening of thejaws are in the same straight line, so that when the bolt-blank is held in the jaws it is in line with the axis of the screw-die carried by the die'chuck E of the revolving mandrel F.

In order that the jaws D D may gripe the bolt-blank and may release it, they are pivoted in an opening ofthejaw-standard I) of the main frame, so that they may open and close like pinchers. In the working machine the jaws are closed and are permitted to open by means of a slide, which is connected by toggle-links with their shanks, and the slideis operated. by means of a cam which is secured to the camshaft B, and is connected with the slide by means of a lever. A spring also is employed to move back the slide whenever the gripingjaws are to be opened.

As no claim is made to any novelty in the means for opening and closing the jaws D D, and as the means above referred to are in com mon use for operating the jaws of other kinds of screw machinery, and as a representation of such means in the drawings would increase their complexity, it has been deemed better to omit the representation of such means from the drawings.

As before stated, the mandrel F is connected by means of cog-gear a a with the clutch-shaft B so that it is caused to revolve by the action of the clutch-shaft. The die-mandrel F and clutch-shaft must, however, be caused to revolve in alternately-opposite directions to cause the die to cut the screw-thread and to back off of the bolt after the screw-thread is cut. In order that the said devices may be revolved alternately in opposite directions while the driving-shaft B continues to revolvein the same direction, the clutch-shaft is connected with the driving-shaft by means of revolving gearing, as follows: Two cog-wheels, a and a are mounted upon the clutch-shaft B with the capacity to turn freely upon it. One of these cog-wheels, a is connected directly with a cog-wheel, a, secured to the driving-shaft B. The other cog-wheel, c of the clutch-shaft is connected with an intermediate cog-wheel, a, secured to the counter-shaftB, which is caused to revolve in the opposite direction to the driving-shaft by the action of the cog-wheel a upon that intermediate cog-wheel, a Hence the clutch-wheels a a are caused to revolve continuouslyin reverse directions, and the connection of the clutclrshaft B with one'orother of said clutch-wheels causes the clutch-shaft B, the mandrel F, and the die connected therewith to revolve either forward, as indicated by the arrow .in Fig. 1, or backward. The clutch-wheels and cog-wheels thus described constitute the revolving mechanism by which the mandrel is caused to revolve in either of two directions.

In order that the clutch-shaft B may be connected with the clutch-wheels a a alternately, the clutch G is provided. This clutch is fitted to slide longitudinally upon the clutch-shaft, but is compelled to turn with it by means of a feather and groove, and its heads are fitted with clutch-teeth arranged in suitable positions to engage with corresponding teeth protruding from the adjacent faces of the clutclrwheels. The clutch is shifted upon the cl utch-shaft to engage with one or other of the clutch-wheels by means of a double-graded cam, d, which is secured to the counter-shaft B and operates upon the movable pins 0 c of a shifting carriage, d. This carriage is arranged to slide upon a bar, 6?, parallel with the clutch-shaft, and is connected with the clutch Gr by afork, 01. which fits in a circular groove of the clutchbody. The shifting-pins c 0 are fitted to slide up and down in sockets of the shiftin g carriage, and whenever either pin is dropped downward in its socket its point is engaged by the shifting-cam d, and the clutch is shifted by the action of that cam, the cam-grade 0 Fig. 16, and pin 0 operating to shift the clutch into connection with the clutch-wheel a and. the camgrade 0 Fig. 16, and pin 0 operating to shift the clutch into connection with the clutch-wheel (o The clutch, the shifting-pins, and the shifting-cam thus effect the reversal of the movement of the mandrel, and constitute the reversing gearing or mechanism of the machine.

IIO

In order that the shifting-pins c 0 may be raised and dropped automatically, two cams, 0 0 are provided, and each of these pin-cams is caused to operate upon its appropriate pin by means of alever, c and c and a link, 0 and c". The pin-cams c t are secured to the shaft B which is constructed to revolve in bearings secured to the main frame, and the revolution of the shaft causes the protuberances of the cams to raise and to drop the pins as required. When the clutch G is in gear with either clutch-wheel a? or a the mandrel F and the die carried by it will continue to re volvein the same direction until the clutch is shifted. The length of time during which the mandrel and die continue to revolve in the same direction should, however, be capable of variation, to adapt the machine to cutting screw-threads having a different number of turns'upon the bolt, or extending difl'erent lengths along the boltshank.

In order that the pin-cams c 0 may be operated automaticall y, but mayat the same time have their operation varied to change or vary the times of shifting the clutch, their shaft 13 is not connected with the driving-shaft by means of invariable combining mechanism, but is connected therewith by means of the following variable-pawl change gearing or mechanism A ratchet-wheel, H, is secured to the end of the shaft B which carries the pineams c 0 and a vibrating pawl, h, is provided to operate upon this ratchet-wheel. The shank of the lever h of the vibrating pawl is connected by a link, h with a crank-pin, b whose shank is secured in a groove which extends radially across a hub, 7r, secured to the counter-sha-ft- B, so that the crank-pin is adjustable toward and from the axis of the countershaft which carriesit. The continuous rotation of the counter-shaft B turns the crank-pin h and causes the pawl h to vibrate at every revolution but the extent to which the pawl vibrates, and consequently the amount of movement which it imparts to the ratchetwheel H, to the changegear shaft 13", and to the pin-cams c c secured thereto, depends upon the position in which the adjustable crank-pin If is secured in the groove of the hub h". It the adjustable crank-pin be close to the center of the hub, the vibration of the pawl is sufficient to move the ratchet-wheel H but one tooth ata time. Hence under this adjustment of the crank-pin the change-gear shaft B and the cams c. 0 will be turned slowly, and the clutch-shaft, mandrel,and die will run for a comparatively long period in one direction before beingreversed. By shifting the position of the adjustable crank-pin h in'the groove of the hub h the extent of movement of the pawl h is varied, and it may be made to vibrate to the extent of two, three,

or four teeth of the ratchet-wheel, in which cases the latter, the change-gearshaft B and the pin-cams c 0 will be turned faster, and the clutch will be shifted at shorter intervals,

corresponding with the cutting of screwthreads, making a less number of turns upon the bolt-shank.

Inorder that the adjustable crank-pin may be readily shifted or adjusted in the groove of the hub h, the crank-pin is in the present example constructed with a tubular body or journal traversed by a screwed stem, having at its inner end the shank which fits in the dovetailed groove of the hub and at its outer end a screw-nut, which is slacked to permit the crank-pin to be adjusted and tightened to secure the adjustable crank-pin in its place. The same result of varying the extent of movement of the pawl may be accomplished by providing the hub h with a series of holes at dilferent distances from the center of the counter-shaft, and by shifting the crank-pin from one hole to another. In practice it is generally suflieient to have a machine capable of four variations orchanges of the operation of the reversinggearing, and consequently the present machine is fitted to vary the vibration of the pawl h from one to four ratchet-teeth. brations of the same extent are required, the pawl It must be made capable of a greater extent of vibration; or, if the vibrations are to be made less in extent, the ratchet-teeth must be made shorter, or the pawl and teeth may be replaced by a vibrating clamp operating upon a wheel-rim, like the means employed to operate the feed-wheels of sewing-machines. The variation of the movement of the pawl or clamp may, if preferred, be effected by shifti ng the leveupin h of the link 71. radially of the pawl-lever h, in place of shifting the crankpin [L3 radially of the counter-shaft; but 1 prefer the latter modification. or clamp-wheel, the variable pawl or clamp, and the adjustable crank-pin, or its substitute, by which the extent of movement of the pawl or clamp is varied, constitute the variablepawl change-gearing of the machine.

When the mandrel F and the screw-die car ried by it are turned in the direction to cut the screw-thread they must be advanced to the bolt-blan k end wise thereof, and must bepushed against it sufficiently to start the cutting of the thread; or, in place of ZtClVttllGll'lg the mandrel, the griping-jaws, while holding the boltblank from turning, may be arranged to slide, and thus advance the bolt-blank to the screwdie. After the cutting is thus commenced the progressive formation of the screw-thread by the screw-die will draw the latter with the mandrel forward as long as the turning of the mandrel in the advancing or cutting direction is continued, and thus cause the screw-thread to be cut to the requisite extent. In order If a greater number of vi- The ratchet-wheel IOO that the cutting of the screw may be started,

the mandrel F and the screw-die are advanced or moved longitudinally toward the gripers or jaws l) D by means of a leading-cam, I. This leading-cam I is secured to the camshaft B and its cam-grade 1?, Fig. 9, operates upon the mandrel F through the intervention of the rocking arm i, the rock-shaft 4?,to which that rocking arm is secured, the second rocking arm, i projecting from the rock-shaft, the slide 1', which is operated by the second rocking arm, the sliding piston-rod i and the arm i of the piston-rod, which last arm acts upon the end of the mandrel F. The arm i of the piston-rod is fitted with an adjusting-screw, 6 so that the screw-die carried by the die-chuck E of the mandrel may be adjusted to its proper position relatively to the bolts to be operated upon. The piston i is fitted with a spring, '6 to move the piston 41 back to its starting position whenever the leading-cam permits such action. It is also expedient to apply a similar spring to the mandrel F to insure its removal from the point of the bolt after the screw-die has backed off thereof.

The time at which the leading-cam operates to do its work depends upon the time at which the mandrel is connected with the advancing clutch-wheel a Hence, if the latter time be varied, the former should vary with it. In order that the leading-cam may act in concert with the variation of the movement of the mandrel due to the action of the change gearing or mechanism before described, the lead ing-cam I is operated at intervals, succeeded by intervals of rest. To this end the camshaft B, that carries the leading-cam, is connected with the revolving driving-hub B (or some substitute therefor,) by means of a clutch, J, which is engaged with the driving-hub B when the leading-cam is to be driven, and is disengaged from the driving-hub when the leading-cam is to remain at rest. In order, moreover, that the same change mechanism which controls the reversing-clutch Gr may also control the action of the leading-cam I, the clutch J, that connects the cam shaft 13 with its driving-hub B is operated by a cam, K, secured to the change-gear shaft B This clutchcam K operates upon the clutch through the intervention of the lever k, the rod and the clutch-fork V, which engages in a ring-groove of the clutch J. The clutchcam K, in the present case, is arranged to disengage the clutch when the leading-cam is to stop acting, and to permit the clutch to engage with the driving-hub J when the leadingcam is to commence acting, a spring, 10 being provided to move the clutch into engagement with the driving-hub whenever the clutchcam K permits this operation.

If itis preferred that the griping-jaws should advance the bolt-blank to the screw-die, the mandrel need not be constructed to slide endwise; but the standard which carries the griping-jaws should be constructed to slide upon the frame, and should be connected with the leading cam so as to be operated by it, this construction being an equivalent for that represented iu the drawings.

In order that the bolt-blank to be screwed or threaded may be presented to the gripingyaws D D automatically at the proper times, a magazine or bolt-holder, L, is provided to contain a supply of bolt-blanks, and mechanism is provided to take one bolt at a time from this bolt-holder and present it to the gripingjaws D D, which hold the bolt-blank from revolving during threading. The bolt-holder L consists mainly of two slabs, l 1, connected at,

their rear ends, with a space between them little wider than the thickness of a bolt-stem, so that the bolt-blanks will lie horizontally in a column one above the other in said cavity, and will easily slip down the same when the lowest bolt is removed. The heads of the boltblanks protrude from the cavity, and are held in place by a head-piece, l, which, with two cheek-pieces, Z Z forms the connection of the side slabs of the bolt-holder at its head. The heads of the bolt-blanks are thicker than the stems thereof. Gonsequentl y the column of superimposed bolts assumes a curved form resembling the spokes of a wheel, and the headpiece l and adjacent ends of the side slabs are curved correspondingly.

In order that the lowest bolt in the boltholder maybe taken therefrom, the boltmover M is provided. This consists of two arms, on m, connected by a stock, m, with a rock-shaft, m, which is fitted to rock in bearings connected with the bolt-holder. The upper edges of the arms are curved concentrically with the rock-shaft for the greater part of their length, so that when their curved edges are beneath the cavity of the bolt-holder they act as a stop to prevent the escape of bolt-blanks. The ends of the arms at of the bolt-mover are notched sufficiently to admit the stem of a bolt-blank. Hence when these notches are brought under the cavity of the bolt-holder they will receive the lowest bolt-blank, and when the bolt-mover is subsequently moved by rocking its shaft at this bolt-blank will be moved laterally from beneath the bolt-holder. While the bolt-blank is thus moved laterally it is prevented from turning axially in the boltmover by the guard l, which is screwed to the side of the bolt-holder, with its lower edge projecting over the track in which the angular shoulder of the blank is carried by the boltmover. The blank is also prevented from changing its position longitudinally by means of a lateral projection, L of the head-piece Z,

and by the side of the guard l, the said projection being at the outer side of the head of the bolt-blank, and the guard being arranged at its inner side or the shoulder thereof. The bolt-mover is operated at the proper times by means of a cam and a spring acting antagonisticall y. The cam N is secured to the cam-shaft B and operates upon the bolt-mover through the intervention of the arm n, the rock shaft a, the second rocking arm, 11?, the connectingrod a the arm a and the rock-shaft m which, as before stated, is connected with the boltmover M. The cam, in the present case, is arranged to move the bolt-mover backward or *movable stops are provided.

into the position to receive a bolt, while the spring is arranged to move the bolt-mover forward, or in such manner as to move the bolt laterally from beneaththe bolt-holder. The spring used for this purpose in the machine represented in the drawings is a helical spring, M, Fig. 7, which is concealed in a tubular cavity of the rock-shaft n, and operates by torsion upon the head of that rock-shaft.

In order that the whole column of bolts in the bolt holder may not drop immediately when the notched ends of the bolt-mover are brought beneath the cavity of the bolt-holder, These stops are by preference two in number, each consisting of a bar, 0, which is constructed to slide crosswise of the cavity of the bolt-holder. The ease or guide 0 of each stop is secured to the side of the bolt-holder, which also is perforated to permit the endsof the stops to enter the cavity beneath the lowest bolt but one. The stops 0 O are provided with springs 0, which force them inward. They are withdrawn from beneath the column of bolts when the latter are to be permitted to drop by means of arms 0 one for each stop, which operate upon studs protruding from the sides of the stops, and are connected with a rock-shaft, 0 which is supported in bearings connected with the bolt-holder L. As these stops operate in concert with the bolt-mover, advantage is taken of this circumstance to withdraw them by connecting their rockshaft 0 with the rockshaft m of the bolt-mover by means of connecting-arms 0 0 Hence whenever the rockshaft of the bolt-mover is operated to move the latter to the position for receiving the lowest bolt-blank in the bolt-holder the stops 0 O are permitted to enter the cavity of the boltmover and hold the other bolt-blanks from dropping; and whenever the bolt-mover has been moved laterally sufficiently to carry the lowest bolt from beneath the bolt-holder the stops 0 O are withdrawn to permit the column of bolts to descend in the bolt-holder, so that the lowest bolt-blank is in the proper position to drop into the bolt-mover at its next operation.

In order that the bolt-blank may be transferred from the bolt-mover to the jaws D D, the transfer-fingers P are provided. These fingers are connected with a vibrating arm, 1?, the shank of one finger, 1), Figs. 5 and 8, being connected rigidly with said arm, while the shank of the other finger, p, is pivoted to said arm, and is provided with a spring which tends to press the pivoted finger toward the rigid finger, the said spring being secured in the head 1) of the arm P. In order that these fin gersmay seize the bolt-blank, the inner faces of their points have notches formed in them, one of which is \/-formed, and the points of the fingers beyond these notches are slightly beveled or sloped outward, so that when the fingers are pressed down endwise upon the shoulder of a bolt-blank lying in the boltmover these sloping points are caused to separate and admit the shoulder of thebolt-blank into the fin ger-notches, where it is held by the action of the fin ger-sprin g. In order that these fingers may be moved endwise upon the boltblank, may transfer it to the griping-jaws, and may return from those jaws, the fingers are moved by vibrating the finger-arm l? by the action of a cam and spring. The finger-cam Q is secured to the cam-shaft B so as to be revolved by it, and operates upon the fingerarm P through the arm P and rock-shaft P The spring which operates automatically to the cam Q is, in this example, the same torsion-spring, a Fig. 7, which operates upon the bolt-mover shaft a, one end of said spring bein connected with the end of the rock-shaft P of the vibrating finger-arm through the intervention of a hub, P The object of making the connection through the intervention of this hub is to enable the force of the spring to be adjusted by winding it up, and for this purpose the face of the hub P is formed with ratchet-teeth, any one of which will engage with a corresponding tooth formed upon the adjacent face of the hub of the rocking arm P Hence by turning the spring-hub P the spring may be wound up and held in that 0011- dition by the engagement-of one of its ratchetteeth with the tooth of the finger-arm. The periphery of the finger-cam is so formed as to raise the transfer-fingers high enough to permit the bolt-mover to move a bolt-blank laterally beneath their points, to let the fingers be depressed upon the bolt-blank so as to seize it, to hold the fingers at rest while the boltmover is withdrawn from the bolt seized by the fingers, and to permit the fingers to. desceud far enough to hold thebolt-blank in line with the axis of the screw-die and the gripingaws.

The action of the fin ger-cam and spring thus far described is to move the bolt-blank to the axial line of the die and griping-jaws D D. If these jaws are so made and opened as to admit the head of the bolt when it is moved downward by the fingers, the bolt-blank, while being moved downward, may be introduced directly between the griping-jaws; but it is preferred to move the bolt-blank between the jaws by moving it endwise head foremost. In order that this movement may be efiected the cam Ris provided. This cam has upon one of its sides a grade which operates upon the lower end of a lever, R, which is pivoted to a standard of the main frame, and operates at its other end upon the shaft I of the fingerarm P. The action of the cam is to hold the finger-shaft from being moved endwise by the endwise pressure of a spring, and the spring used for such endwise movement is the same spring a which has before been described, and which, being compressed endwise between the head of the hollow rock-shaft a and the hub P tends to move that hub, the vibrating finger-arm P with its fingers P, and the shaft IIO to which said arm is secured endwise in the proper direction to carry the fingers toward the griping-jaws.

The cam R is secured to the cam-shaft 13 which also carries the cams Q N, for controlling the operation of the transferring-fingers P and the bolt-mover M and the grade of the cam lit is so set relatively to the transfer finger-cam Q that when the transfer fingers have, by their downward movement, carried the bolt to the axial line of the griping-jaws said fingers are .permitted by the cam B to move sidewise toward the clamping-jaws N, so as to introduce the head of the bolt between them and hold the blank in this position until the jaws close upon its square shoulder. Afterthejawsha-ve closed upon the bolt-blank the cam 1t moves the fingers sidewise away from the jaws to put them in the proper lateral position for a succeeding operation.

The cams N Q R, which thus control the movement of the bolt-blank to the clampingjaws D D, are all secured to the cam-shaft 13*, which carries the leading'cam I, so that the bolt-mover, stops, and transfer-fingers act in concert with each other and with the advance of the die-holder E. Moreover, as the operation of this cam-shaft is controlled by the variable-pawl change gearing or mechanism, as above described, the lengths of the intervals between the successive operations of feeding bolt-blanks can be changed to permit the threads to be cut a greater or less number of turns upon them.

When the machine is employed to cut the screw-threads of bolts which have angular shoulders, either square or polygonal, it is important that the bolt should be presented to the jaws with the corners of its angular shoulders in the proper positions to be grasped without bruising in corresponding angular notches of the said jaws. In order to insure this result the guard Z} at the side of the boltholder has its lower edge curved and set above the lower sides of the notches of the bolt-mover a distance slightly greater than the thickness of the angular shoulder of the bolt between its opposite sides. Hence the edge of this shoulder-guard l co-operates with the bolt mover to form a species of channel and hold the bolt with the corners of its angular shoulder in the proper axial positions which they should have to be so presented by the transfer-fingers to the griping jaws that the angles of the boltshoulder may correspond with the angles of the notches of the jaws. This shoulder-guard is also used in the machine, as before stated, to prevent the bolt from excessive longitudinal movement in the bolt-mover; but a separate guard may be used for that purpose.

In order that the bolt-blank may be moved by the transfer-fingers to its exact position axially of the spring'jaws and die, the spring a is employed to cause the descent of the transfer-fingers, and a stop, S, is employed to limit their descending movement. An adjustable bumper, s, also is fitted to the finger-arm P, to strike the stop S, and the precise position at which the bolt is presented by the transfer-fingers can be determined by adjusting this bumper, or, if preferred, by using a fixed bumper and making the stop adjustable.

The die by which the threading or screwing is effected is, by preference, a solid die, and, as before stated, is carried by the die chuck or holder E, which is secured to the head of the revolving mandrel F. The solid die, if made according to the last part of my invention, is a block of steel of conoidal form, as represented at T, Figs. 12, 13, and 14, having upon its periphery several projections or teeth, t, whichfit into corresponding notches formed in the cavity of the die-chuck E. The butt of this die is fiat, so that it may set truly against the head f of the die-mandrel F, and the die is held there by the action of the die-chuck, which is composed of the screwed sleeve 0, Fig. 12, and the screwed gland e, the first of which bears against the inner side of the mandrel-head and holds the gland c and the die within it firmly in place. Dies of this construction are readily forged to the exact shape required by means of suitable forging-dies used in a drop-press, the cavity of the die conforming in form and size with the cavity of the die-chuck in which the die is to be used. The die is then drilled and cut while held in a die-chuck corresponding with that of the threading-machine, so that the die will fit the chuck of the threading-machine without any dressing up. Hence the cost of making dies for the screw'threadin g machine is reduced to a minimum. 011 the other hand, the die is free from any groove which requires a milling operation or a planing operation to form it, and which, by nickin g the body of the die, renders it liable to crack in the hardening operation to which the die is necessarily subjected.

When the threading-machine is to be put to work the variable-pawl change mechanism is adjusted according to the number of turns of screw-thread to be out upon the bolts.

The bolt-blanks are put into the bolt-holder Lby a child, and by the automatic operation of the machine the bolt-blanks are taken from the bolt-holder, one at a time, by the bolt-mover. The downward movement of the column of boltblanks in the bolt-holder is temporarily checked by the stops. The bolt-blank is presented for the action of the transfer-fingers, and is seized by them. The bolt-mover is withdrawn from beneaththe bolt-blank, which is then transferred to the griping-jaws. These jaws seize the blank, the die advances upon it and cuts the thread to the required extent, the die backs off of the bolt by reason of the reversal of the movement of the mandrel, and the jaws are opened to permit the threaded bolt to drop. If the bolt hangs in the jaws it is knocked IIO downward from them by the downward move ment of the next succeeding bolt-blank carried by the tranfer-fingers.

The adjustment of the machine to the cutting of threads having a different number of turns is effected by changing the position of the adjustable crank-pin it as before described.

It is expedient that the time at which the feeding of the bolt commences relatively to the time of reversal of movement of the screw-die should be capable of being changed, and this capacity is given in the machine above described by constructing the cam-grade of the clutch-cam K of two parts, one of which is movable concentrically of the other, so that the grade, as a whole, may be lengthened or shortened in the direction of the periphery of the cam.

The movable part of the cam-grade is secured by a clamp-screw.

The speed at which the screw-die is advanced or pushed against the point of the bolt-stem should correspond with the pitch of the screwthrcad to be formed.

In order that the same leading-cam I may be employed to advance the screw-dies for screw-threads of different pitches, the rocking arm 6 is slotted, so that the pin i, through which that arm operates upon the slide can be set at greater or less distance from the rockshaft i thus causing the slide and the mandrel and screw-die which are connected with that slide to be moved with greater or less speed by the same movement of the leadingcam I.

In order that the bolt-holder and the parts connected with it may be set to the proper positions to suit the bolts to be threaded, the standard U, which supports the bolt-holder, is constructed with a foot, u, which can be moved along the rest V, which supports it, and can be secured in any desired position by a screwbolt.

For purposes of adjustment some of the rock ing arms of the machine are constructed with split hubs, and are secured to their shafts by clamping the split hubs by clamp-screws. The ends of some of the arms also are slotted, so that the pins by which the arms are connected with other parts may have their positions changed.

The combination ofthe variable-pawl chan gegearing with reversing-gearing, as above de scribed by me, may be used with advantage in machines for other purposes than threading bolts.

I claim as my invention- 1. The combination, substantially as before set forth, of the change-gearin g shaft and its cams, the ratchet-wheel, variable vibrating pawl, and adjustable crank-pin.

2. The combination, substantially as before set forth, of the clutch, shifting-pins, shiftingcam, pin-cams, camshaft of the change-gearin g, ratchet-wheel, vibrating pawl, and adjustable crank-pin.

3. The combination, substantially as before set forth, of the jaws for holding the bolt blank stationary, the revolving sliding mandrel, the boltholder, the bolt m over, the transfer-fingers, and the variable-pawl change-gearmg.

4. The combination, substantially as before set forth, of the transfer-fingers, finger-cam,

- fin ger-cam shaft, drivin g-h ub, and clutch with the variable-pawl change-gearing.

5. The combination, substantially as before set forth, of the bolt-mover, bolt-mover cam, camshaft, driving-hub, and clutch with the variable-pawl change-gearing.

6. The combination, substantially as before set forth, of the bolt-holder, the bolt-mover, the stops for checking the descent of the bolts in the bolt-holder, and the transfer-fingers which take the bolt from the bolt-mover.

7. The combination, substantially as before set forth, of the griping jaws for holding the blank stationary, the bolt-holder, the boltmover, the transfer-fingers, arranged to move both endwise and sidewise toward and from the gripin g-jaws, and the variable-pawl changegearing.

8. The combination, substantially as before set forth, of the bolt-holder, the bolt-mover, and the shoulder-guard, whose lower edge operates on the shoulder of the bolt while in the bolt-mover.

9. The combination, substantially as before set forth, of the bolt-mover, the shoulderguard, and the transfer-fingers.

-10. The combination, substantially as before set forth, of the bolt-holder and bolt-mover with a shoulderguard whose edge operates on the shoulder of the blank while in the boltmover, and whose side is arranged in the proper position to operate on the inner side of the head of the bolt and prevent excessive longitudinal movement of the bolt.

11. The combination, substantially as before set forth, of the bolt-mover, the shoulderguard, the transfer-fingers, and the gripingjaws, to which the bolt is presented by the tldllSfGPfillgGlS.

12. The combination, substantially as before set forth, of the die-holder, the revolving sliding mandrel, the leading-cam, the slotted rocking arm, which enables the speed with which the die is advanced to be varied, and the variable-pawl chan ge-gearin g.

13. The combination, substantially as before set forth, of the conoidal screw-die with a diechuck consisting of the screwed sleeve and screwed gland operating in connection with the mandrel-head.

Witness my hand this 11th day of February, A. D. 1879.

SAMUEL LORD WORSLEY.

Witnesses A. B. SPRAGUE, ADOLPH HESSLING.

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