US2262698A - Thread rolling machine - Google Patents

Description

4 Sheets-Sheet l J la 1w W m ,W l l\\\\\ mm IW y @11 a w om G. v H bv i. mm l. m. QQ i.. 1m. 2J .11. nl: n n u @Q v mwlmw. 9 N 1... HH.. \h LIFT. 1 @IMJ 1 l P mm|i m H. PELLAND Filed Jne 12, 1959 THREAD ROLLING MACHINE -JVHHHMWHH i ..N0v.v11, 1941.

Nov. 11, 1941. H. PELLAND THREAD ROLLING MACHINE Eiled June 12, 1959 4 Sheets-Sheet 2 /m/e/7/0r /lf Pe #and Kllll l|| |l...|| L Il l l no ww um, mw W Nov. 11, 1941. H, PELLAND 2,262,698

THREAD ROLLING MACHINE Filed June 12, 1959 4 sheets-sheet NOV-'11, 1941. H., PELLAND l 2,262,698

THREAD ROLLING MACHINE Filed June l2, 1959 4 Sheets-Sheet 4 ffy Patented Nov. 11, 1941 UNITED STATES PATENT ortica THREAD ROLLING MACHINE Herv Pelland, Ville Emard, Quebec, Canada Application June 12, 1939, Serial No. 278,780

9 Claims.

This invention relates to improvements in thread rolling machines and in a method of rolling threads, and the primary object of the invention is to provide a machine so co-nstructed and arranged as to roll a thread during each stroke of the machine, that is, to roll two threads during each revolution of the machine main shaft.

A further object is to provide a thread rolling machine having improved blank feeding means adapted to position blanks with accuracy and certainty and to feed the blanks so positioned to the thread rolling dies of the machine in such a way and at such time that the blanks cannot become displaced.

A still further object is to provide a threadl rolling machine capable of rolling twol different threads during the same period of operation.

Another object is lto provide a thread rolling machine of the foregoing character capable of adjustment through a comparatively wide range to roll thread blanks of a considerable number of different sizes.

Still another object is to provide a thread rolling machine of simple, durable and compact construction which may be easily and quickly adjusted and may be operated at very low cost.

Various other objects and the advantages of the invention may be ascertained from the following description and the accompanying drawings.

As to method, the invention consists broadly in feeding blanks between relatively moving thread rolling dies, the direction of feed being in the direction of movement of a moving die at the moment the blank enters between and is gripped by the dies.

As to apparatus, the invention consists broadly in providing two pairs of relatively movable dies arranged in tandem, one die of each pair 'being carried by a slide operatively connected with a power driven crank shaft and the dies being so arranged that the pairs operate alternately and perform a thread rolling operation at each stroke of the slide, in combination with two blank feeding means operating alternately and in synchronism with the lslide to receive blanks from magazine means and transport the blanks to the dies and feed the blanks between the dies in a direction corresponding to the direction of the adjacent moving die.

In greater detail, the invention consists, both as to method and as to apparatus, in the features and combinations of features described in the following description and/or shown in the accompanying drawings together with all such, :f

modications or substitutions of equivalents therefor as are within the scope of the appended claims.

Thread rolling machines at present in general use suffer from one or more of a number of structural and operative disadvantages which seriously limit the amount and perfection ofthe output. In the machines generally in use, a single pair of dies is provided, one being stationary and the other reciprocated past it by means of a crank shaft and connecting rod. The thread rolling operation is performed during movement of the reciprocating die in one direction but cannot be performed during the reverse or return movement of the moving die, with the result the moving die is idle while returning to its starting position. This means that' half of the machine time is unproductive. Another disadvantage is that blanks are usually fed to the dies in a direction transverse of the direction of die movement with the result that the blanks are frequently improperly positioned between the dies and a defective product made.

According to the present invention, these disadvantages are overcome by providing two sets of dies alternately operating to perform a thread rolling operation during each stroke of the machine, thus doubling the production without increasing the speed ofthe machine and without materially increasing the power consumption. The blank holding magazines are mounted at opposite ends of the machine and supply blanks through the usual chutes to cylindrically curved grooves extending from the chutes to the intake ends of the stationary dies. Cylindrically curved plates sliding in the grooves form chute gates and blank transferring and feeding means which move the blanks in the gripof the dies with movement in the same direction as the die movement, so that change in the direction of blank movement with consequent liability to malpositioning of the blanks in the dies is avoided.

In the accompanying drawings which illustrate one embodiment of the invention but to which embodiment and the details thereof the invention is not confined since other embodiments and modiflcations of detail are possible and contemplated.

Fig. 1 is a plan View of a double acting thread rollingmachine showing the parts in their respective positions at full forward stroke.

Fig. 2 is a side elevation of the machine of Figure l.

Fig. 3 is an elevation of the left hand end of the machine shown in Figures 1 and 2.

'- Fig. 4 is a cross-sectional View on the line 4-4 of Figs. 1 and 2.

Fig. 5 is a plan View on an enlarged' scale of the die holder and feed mechanism shown at the right hand end of Figure 1.

Fig. 6 is a front elevation on an enlarged scale of the die holder and feed mechanism shown at the left hand end of Figure 1.

Fig. 7 is a rear elevation of the parts shown in Figure 6.

Fig. 8 is a bottom plan View of the parts shown in Figures 6 and '1.

Fig. 9 is a vertical longitudinal vsectional view sectional view mounted on the base and comprises a pair of inflexible spacedyokes I4 arranged mouth upwards and connected at the back of the machine by a heavy guide member I5 preferably L-shaped in cross-section (Figs. 3 and 4) and provided at one end with an extension I6 carrying a crank-shaft bearing I1 and counter-shaft bearing I8. At the front of the machine the yokes I4 carry tables I9 at approximately the same level as the lower arm of the guide, which tables may be separated throughout' the space between the yokes, as shown in vFiguresl 1 and 2 but may equally, if greater strength is desired, be continuous between the yokes at the front of the machine.

. A crank-shaft 2D is journalled in the bearing I1 anda counter-shaft 2I is journalled in the bearing I8. The crank-shaft carries a heavy disc 22 having flywheel effect which is gear toothed at its circumference as at 23, and'meshes with a pinion 24 fixed to the shaft 2 I Driving means such as belt pulleys 25 is provided for the counter-shaft. The disc 22 carries a crank pin 26 on which is mounted a connecting rod 21 pivotally connected by a pin 28 to a heavy slide 21 reciprocatable on the guide I5 and retained thereon by a cap plate 30 secureditov the guide.

Die holders 3I and 32 are mounted on the .tables I9 and are exactly similar but are right hand and left hand as clearly shown in Fig, 1. These holders are clamped to the tables by studs and nuts or cap screws 33 passing through transverse slots 34 (Fig. 8) in the holders and into the tables. The slots 34- permit adjustment of the holders toward and away from the slide. The bottom surface of each die holder is formed with a transverse slot 35 into which fits snugly a pin or rib 36 carried by the table (Figure 6) and serving to hold the die holders against movement longitudinally of the slide.

- The die holders are adjusted toward and away fromthe slide and are heldin their adjustment by means` of abutment screws 31 and traction screws 38 passingthrough the front arms of the yokes I4. There are two abutment screws 31 for ea ch..dieV holder, arranged approximately 1 equidistantly on opposite sides of a single traction screw. The abutment screws 31 are threaded ..1 l into the yokes and engage the front faces of the dieholders while the traction screws merely pass through the yokes and through longitudinal slots l --39 in the die holders into threaded engagement with axially vertical cylindrical nuts 40 rotatable in the die holders and retained by cover plates 4I (Figs. 5, 6 and 8). The arrangement of slots 39 and nuts 40 enables the die holders to beangularly adjusted relatively to the slide without jamming the traction screws.

Each of the die holders is provided on its rear face with a die receiving slot 42, which is undercut at its ends in the usual manner to retain a die of usual form. The front face of the slide is provided with suitably spaced die receiving slots 43 similar to the slots 42. yAs shown, the spacing of the slots 43 is somewhat less than the spacing of the slots 42 for reasons which will be Vhereafter explained. Thread rolling dies 44, 45

and 46, 41 are mounted in the slots 42 and 43 and retained by means 48, such ascap screws or studs and nuts and by wedges 49 of any suitable form. The dies 44, 46 are mounted in the holdersV 3|, 32 and the respective cooperating dies 45, 41 are mounted in the slide.

'Blank feeding mechanisms are associatedl with and-in part mounted on the die holders 3l and 32.

The remote ends of the die holders are cylindrically curved as shown at 50, the axis of curva.-

ture being vertical and the angle subtended at the axis being somewhat more than 180. Any

suitable form of blank holding magazines (not shown) are provided at the ends of the machine and include blank chutes 5I leading to the die holders, the ends of the chutes being spaced from the curved ends of the die holders sufficiently for thev passage between them of the cylindrically curved blank feeders 52 and 53, which also serve as gates controlling the escape of blanks from the magazine chutes. Associated with the curved ends of the die holders are blocks 54 each having the end adjacent the `die holder concavely cylindrically curved, the radius of curvature being slightly greater than that of the die holder ends. These blocks are clamped to the tables I9 by cap screws or studs and nuts indicated at 55, with their concave ends normally parallel with and spaced from the curved ends of the die holders. The tables I9 are provided outwardly of the blocks 54 with upstanding lugs 56 carrying adjusting screws 51 threaded into the blocks to adjust the same in the longitudinal direction of the machine and toward and away from the die holders. These blocks 54 in conjunction with the curved ends of the die holders define arcuate passages 58 extending rearwardly from the lower ends of the magazine chutes and curving into the line of the gap between the dies 44, 46-and the dies 45, 41. The blank feeders 52 and 53 move freely back and forth in the passages 58 to transfer blanks from the chutes to the dies.

Each of the feeders or gates 52 and 53 consists of a cylindrically curved plate subtending at its axis of curvature an angle of slightly more than Each ofthe plates 52 and 53 is mounted at the outer end of an arm 59 located in a recess 60 on the lower surface of the die holder. The inner end of the arm is fixed to the lower end of a spindle 6I journalled in the die holder coaxially with the curved end surface 50 thereof. The spindle is provided with a collar 62 bearing against the upper surface of the die holder and is held in place by a cone pointed end bearing 63 engaging in the upper end of the spindle and adjustably mounted in a bracket 64'secured to the die block, as by being threaded vinto the bracket. If desired, a similar end bearing 65 may be provided for the lower end of the spindle, being threaded intothe die holder. An actuating arm 66 `is rotatably mounted at one end on the spindle and is pressed by a spring 61 and nut 68 screwed on the spindle, against the collar 62 so as to have frictional driving engagement therewith.

The free ends of the actuating arms 6B on the two die holders are connected by a link 69 pivotally connected thereto so that the two arms and the feeders connected thereto will operate in unison. The end of this link 69 nearer the crankshaft is connected by a universal joint 10 with a connecting rod 1I having pivotal engagement at 12 with a block 13 rotatably mounted on a crank pin 14 adjustably secured on a crank arm 15 adjustably secured to the crank pin 26 in front of the connecting rod, the arm projecting toward the centre of the disc 22, so that the crank pin 14 moves in a smaller orbit than the crank pin 26. The rod 1I is provided with length adjusting means 16.

The magazine chutes each comprise a pair of spaced parallel inclined bars 11 between which the bodies of blanks pass with their heads resting on the upper edges of th-e bars. The front bare of each chute is provided with a thin extension 18 bridging the passage 58 and closely overlying the die holder.

In the space between the yokes I4 and in front of the guide I5, a forwardly sloping chute plate I9 is provided. A guard plate 80 extends b-etween the yokes above the lower end of the chute plate. A division wall 8I is mounted on the chute plate and extends from the line of the dies forwardly to the guard plate 80. The rear end of the Wall is flared to right and left as shown at 82 in Figure l, so as to deflect the threaded product forwardly. The lower edge of the wall 8|, which extends at the front end below the yokes, is flared to right and left, as shown at 83, Fig. 2, so as to deflect the products of the two sets of dies in opposite directions and thus effect a separation thereof which is necessary if the products are of different sorts.

Each die holder is provided with a screw 84 passing longitudinally therethrough in the recess 6I! and serving as an adjustable stop limiting the forward movement of the feeder arm 59.

It has been pointed out that the arc of curvature of the feeders or gates 52 subtends an angle of slightly more than 90, that is to say, the feeder is somewhat more than the quadrant of a cylinder. This excess over the quadrant enables the front portion of the feeder to block the mouth of the chute when the rear edge of the feeder is at the blank delivery point, which is 90 from the chute, all The curvature of the die holder end beyond the semi-cylindrical is to accommodate the excess of the feeder beyond the quadrant. It will be understood the foregoing degrees of curvature are not limitative but depend upon the blank receiving and discharging points being 90 apart. If these points are either more or less than 90 apart, the circular measures of the feeders and die holder ends will be altered accordingly.

A feature of the invention is the novel form of wedges 49 used. In addition to the usual blade 85 which tapers from the back to the face of the die and from the top to the bottom of the die, there is provided a rib or flange 86 extending behind the die at an angle to the die f engaging side of the blade, as clearly shown in Figures 1 and 8, and engaging in a dovetail slot in the slide or die holder. This rib positively holds a loosened wedge from leaning into the gap between the dies and being struck by and as shown in Figure 5. 1

damaging a die. In addition, the lower end of the wedge is provided with a positioning and steadying pin 81 which extends below the steadies the lower end of the wedge where it is not tightly gripped between the die and the adjacent wall of the die slot, thus minimizing the tendency of the wedge to work loose. At the upper end of the wedge a head 88 is provided on the back of the wedge to facilitateV removal.

The operation of the machine is as follows:- As shown in Figures l and 2, the machine is at full stroke and the slide ready tocommence mov-ement to the left. As shown in part A of the diagram Fig. 11, the right hand feeder 52 has just positioned a blank between the adjacent ends of the dies 44, 45 and the left hand feeder 53 has uncovered the end of the magazine chute and allowed a blank to move from the chute into the path of the feeder. As the crank-shaft rotates, it causes the slide I5 to move to the left so that the die 45 passes the die 44 and the blank is rolled between them and threaded in the usual manner. It will be noted the crank arm 15 is set slightly out of the centre line of the connecting rod 21, so that the feed operating crank pin 14 lags slightly behind the die operating crank pin with result that the feeder 52 remains in its rearmost position long enough to ensure the blank being caught by the dies. It will also be noted the front end of the feeder 52 closes the lower vend of the chute 5I. After the slide 29 commences to move to the left, the feeder 52 commences to move forward and the feeder 53 to move' backwards and push a blank through the arcuate slot 58 toward the die 46.

When the die has passed the die 44, the rolling of a thread on the blank previously fed between them is completed, as shown in part B of Fig. l1, and the finished screw falls onto the right hand portion of the chute 19 down which it slides and escapes into a receptacle placed on the tray I2. The dies 45, 61 continue to move to the left until the die 41 completely passes the die 45, as shown in part C of Fig. 1l. At this moment, the back movement of the feeder 53 is complete and a blank has been placed in readiness to be ycaught between the dies 45, t1 when the slide commences to move to the right, The feeder 52 has, meanwhile, uncovered the end of the magazine chute and permitted a fresh blank to pass from the magazine into feeding position in rear of the feeder (part C, Fig. 1l). As the slide moves to the right, a blank is threaded between the dies'll, 41 and the feeder 52 advances ablank toward the dies 44, 45, as shown in part D of Fig. 1l.

The relation of the foregoing operations to rotation of the crank-shaft is that during approxirnately one-third revolution a blank is threaded between dies 44, 45; the feeder 52 moves forward to receive a fresh blank and the feeder 53 moves back to plaoe'a blank4 in proximity to the dies 45, 41, as will be seen by comparing parts A and B of Fig. ll. During the next approximately one-sixth revolution, the die 41 moves clear of the die 45 and the blank feeding operation is completed by feeder 53 while feeder 52 uncovers the magazine chute and receives a fresh blank, as will be seen by comparing parts B and C of Fig. l1. During the next approximately one-third revolution, the blank is threaded between dies 45, 41; the feeder 53 moves forward to receive a fresh blank and the feeder 52 receives and moves a fresh blank into die and proximity to the dies44, 45, as will be seen by comparison of parts C `and D of Fig. l1.V During the ensuing. approximately one-sixth revolution, which completes the cycle of operation, the die f -45 clears the die 44 to receive a fresh blank, the

blank feeding operations. -cess movement, or over-travel of the moving dies 45, 41,-.the'stationary dies 44, 46 are set farther feeder'.r 52 pushes theblank in threading position and the feeder 53l uncovers the magazine chute and receives a fresh blank, as will be seen by comparison ofparts D and A of Fig. 1l.

rFrom the foregoing, it will be apparent that, as regards the thread rolling operation, the only idle periods 'of the cycle are the two one-sixth revolutions occurring-between positions B and C and between positions D and AV of Figure 1l. During these Vidle periods the dies 45, 41 move vfurther than is necessary for thread rolling, the

time of the excess movement being occupied by theV blankA receiving and the final part of the Because of the exapart than the moving dies, to the extent 'of the over-travel, as clearly seen by comparison ofl the positions of die 45 in parts B and C or of die 41 in parts D and A `of Fig. 1l. The overtravel and the idle portion of revolution just described are now preferred, but are not absolutely necessary, since by reducing the angular travel fof'the feeders or increasing their speed relatively to` the speed ofthe dies, the over-travel of the dies may be reduced.

As 'will be seen, the travel of the slidev l5 and dies 45, 41 vis not adjustable, wherefore no longitudinal adjustment'of the die holders 3l and132 and dies 44, 46 is provided for, but on the contrary, the pins 36 (Fig, 6) position the die holders precisely with reference to the slide and hold them against any slight movement that might arise from the die holders taking up clearance between themselves and their clamping screws 33 and which would detrimentally alter the relation of the feeders to the crank pin 14. The die holders are, however, adjustable toward and away fromY the slide toenable blanks of various diameters to be threaded. When the die holders are adjusted toward or away from the slide, the

vblocks 54 should be adjusted respectively inwardly or outwardly so as to obtain corresponding adjustment and substantially uniform width of the arcuate passages 58. If necessary, feeders of different thicknesses may be used according to the adjustment of the machine. The feeders themselves may be adjusted to different diameters of blanks, either by adjusting the crank pin 14 along'the crankl arm 15 or by adjusting the effective length ofthe rod 1I. By adjusting the angle of the crank arm 15, the movement of the feeders may be advanced or retarded relatively to the movement of'the dies, so as to exert the proper feeding pressure on the blanks at the moment they engage both dies and ensure their being grasped and rolled by the dies. If a blank should become jammed in the slot 58, the friction drive of the feeders (62, 66 of Fig. 9) will slip and protect the machine'parts from damage.

During the nal part of blank feeding operation, when the moving die is stationary at the moment of changing direction, the feeder places the blank between the dies. Owing to the lag of the feeder crank pin 14 behind the slide crank pin 26, the feeder is completing its movement as `the moving die commences to move, so that the feeder presses the blank between the dies with pressure exerted in the 'direction of die movement` This nal movement and pressure of the Vas the upper surface of the dies. When adjusting the machine to a given diameter of blank, the die holders are adjusted toward or away from the slide and the blocks'54 are adjusted longitudinally of the slide, so that the width of the passage 58 is slightly greater than the diameter of the blank. When a blank passes from the chute into the passage 58, the blank is suspended by its head, the support being at diametrically opposite points on the blank, so that the blank tends to hang in vertical position and to be moved along the passage with its head sliding on the die holder and block 54. The upper edge of the feeder also engages under ythe blank head and gives an additional point of support thereto, while the advancing edge of the feeder which is vertical engages the entire length of the blank under the head and holds it in vertical position and against displacement due to vibration or other cause, so that the blank isproperly presented to the dies. When the type of screw being produced does not permit of the head sliding directly on the upper surfaces of the `die holders and blocks 54, any suitable auxiliary supporting means, such as is customarily used, may be provided to support the blank at a higher elevation.

rers and having the ends thereof adjacent the die holders cylindrically concavely curved and forming with the die holders curved black passages leading to the die; blank supplying chutes terminating at the ends of said passages remote from the dies; blank feeders oscillatable in said vblank passages to transport blanks fromV the chutes to the dies; means to reciprocate said slide and means actuated by said slide driving means kto oscillate said blank feeders.

,2. Structure according to claim l in which the blank feeders` are cylindrically curved plates of a size to serve also as gate controlling egress of blanks from the chutes.

comprising a frameg" a slide therein; two pairs of co-operating dies, one die of each pair being carried by the frame, said die pairs being arranged in end to end spaced relation, the slide carried dies being spaced apart approximately the length of one of the frame carried dies and the frame carried dies being spaced apart a greater distance than the slide carried dies; means to feed blanks to the die pairs alternately, and means to reciprocate the slide and to actuate said blank feeding means.

4. A thread rolling machine comprising a frame; a slide reciprocatable in the frame; a die holder adjustably mounted on the frame adjacent the slide, said die holder having an end cylindrically curved about a vertical axis; a spindle rotatably mounted in the die holder co-axial with the holder curvature; a blank chute terminating adjacent the curved end of said die holder; a blank feeder curved in conformity with the end of the die holder adapted to travel between the end of the blank chute and the die holder; an arm adjustably mounted on said spindle carrying said blank feeder; a collar on said spindle; a driving member rotatably mounted on said spindle; an adjustable spring means mounted on the spindle pressing said driving member into frictional driving engagement with said collar; a pair of dies mounted one in said slide and one in said die holder; and means for reciprocating said slide and for actuating said feeder driving means.

5. A thread rolling machine comprising a frame including a guide; a table beside the guide and a yoke connecting the guide and table; a slide reciprocatable in the guide; a die holder secured to the table and adjustable toward and away from the slide, said die holder having an end cylindrically curved about a vertical axis; a block secured to the table and adjustable longitudinally of the slide, said block having the end thereof adjacent the die holder concavely curved at a radius greater than the radius of curvature of the die holder, said block and die holder forming an arcuate blank passage; a blank chute terminating at one end of said blank passage; a pair of co-operating thread rolling dies mounted one on the slide and one in the die holder at the discharge end of said arcuate passage; a blank feeder oscillatable in said arcuate passage to transfer blanks singly from the chute to the dies, said feeder constituting also a gate adapted to retain blanks in the chute; and means to reciprocate said slide and to actuate said blank feeder.

6. A thread rolling machine comp-rising a frame; a slide reciprocatable in the frame, a pair of die holders in longitudinally spaced relation beside said slide; two pairs of co-operating thread rolling dies, the dies of each pair being mounted one in a die holder and one in said slide; blank chutes terminating adjacent remote ends of said die holders; oscillatable blank feeding means arranged to transfer blanks from the chutes to the die pairs, said feeding means each including a blank engaging blade, an actuating arm and frictional driving means operatively connecting said arm and blade; a crank shaft including a crank pin and operative connection between said crank pin and the slide; an arm adjustably mounted on said crank pin; a second crank pin adjustably mounted on said arm; a linkage between the actuating arms of the two feeders; and operative connection between said second crank pin and said linkage including a universal joint. v

'7. A thread rolling machine comprising a frame; a slide reciprocatable in the frame; a pair of die holders adjacent said slide spaced in the longitudinal direction thereof; two pairs` of co-operating thread rolling dies, the dies of each pair being mounted one in a die holder and one in the slide, the dies carried by said slide being closer together thany the remaining dies in the longitudinal direction of the slide; a blank chute and a blank feeding means associated with each die holder; land lmeans to reciprocate the slide and to actuate said blank feeders in synchronism with slide movement whereby a blank may be threaded during each stroke of the slide.

8. A thread rolling machine comprising a frame; a slide reciprocatable in the frame; a die holder mounted on the frame; a pair of co-operating dies one of which is mounted in the slide and the other in the die holder; a blank chute vterminating adjacent the die holder; a spindle Vjournalled in the die holder; an arm adjustably mounted on said spindle; a blank feeder mounted on said arm and constituting a gate for said chute; a collar on saidvspindle; an actuating arm rotatably mounted on the spindle and engaging said collar; a nut threaded on said spindle; a spring in compression between the nut and actuating arm pressing the arm into frictional driving engagement with said collar; adjustable end bearings for said spindle; a crank shaft; operative connection between the crank shaft and slide; and separate operative connection between said crank shaft and said feeder actuating arm adjustable with respect to the slide operating means, whereby the operation of the blank feeder may be advanced or retarded relatively to the operation of the slide.

9. A thread rolling machine comprising a pair of co-operating relatively reciprocating dies, a blank chute disposed in parallel with the direction of die reciprocation and adapted to deliver blanks in axially vertical position, and blank feeding means adapted to move the blanks singly in axially vertical position through an arcuate path from said chute and to feed the blanks between the dies and in a direction coinciding with the direction of die movement at the commencement of the thread rolling operation.A

HERV PELLAND.

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