US1222954A - Threading mechanism for automatic lathes. - Google Patents

Description

1.1. HOGAN, J. F. JUDD & L. M. WA TE.

THREADING MECHANISM FOR AUTOMATIC LITHES.

APPLICATION HLEU MAY I9, 1915.

1,222,954. Patented Apr. 17. 1917.

3 SHEETSSHET I.

J06 Judd ba Wane gr-mrn r/Ewe: $55922! 1.1. HOGAN, J. F. mun '& L. M. WAITE.

THREADING MECHANISM FOR AUTOMATIC LITHES.

Patented Apr. 17, I917.

APPLICATION FILED MAY I9. NIB.

3 SHEET,8SHEET 2.

.II III RN mmN J. 1. HOGAN, J. F JUDD &'L. M. WAITE.

THREADING MECHANISM FOR AUTOMATIC LAIHE'S.

APPLICATION FILED MAYIQ, ms. 1,222,954. Patented Apr. 17,1917.

2 SHEETS-SHEET a UNITED STATES PATEFT OFFICE.

JAMES J. HOGAN, JOHN F. J UDD, ANI) LYMAN M. WAITE, HF, FITCHBURG, MASSACHU- SETTS, ASSIGNORS TO FITCHBUBG IVIAGH'INE WORKS, 0F FITGHBURG, MASSACHU- SETTS, A. CORPORATION OF MASSACHUSETTS.

'I'HBEADING, MECHANISM FOR AUTOMATIG LATHES.

SpecificationofLetters Patent.

Patented Apr. 1'7, 1917.

Application filed May 19, 1916. Serial No. as .659,

To all whom it may concern:

Be it known that we, JAMEs J. I'IOGAN, JOHN F. JUDD, and LYMAN M. Warm, citizens of the United States, all residing at Fitchburg, in the county of Worcester and State of Massachusetts, have invented a new and useful Threading Mechanism for Automatic Lathes, of which the following is a specification.

This invention relates to a threading mechanism for automatic lathes of the type in which the threadingdie is continuously revolved in. the same direction as the stock, but at a speed less or greater than that of the stock according as the die is cutting or running 011 of the stock.

While many features of our invention are capable of general application, we have herein shown the invention'as applied to a multiplespindle automatic lathe of the general type shown in the patent to Grant, No. 926,735, issued July 6, 1909. In this type of lathe the workiis both rotated and advanced longitudinally toward the tools which are mounted in a fixed tool head.

It is the general object of our invention to provide an improved threading mechanism particularly adapted to this type of lathe, in which the mechanical construction is simplified and the operation is made more reliable.

Withthis general object in view, one fea ture of our invention relates to a construction by the use of which the threading mechanism may occupy either one of two successive positions in the lathe, or if desired two threading mechanisms may be used at thesame time, one in each of two successive positions. A second feature of our invention relates to the provision of a support on whichis mounted the mechanism which-com trols the threading die, this support and the mechanism thereon being readily remov able and replaceable as a unit. Other features of our invention relate to the provision of an improvedlsystem of controlling devices for the threading mechanism by which the necessary adjustments canbe easily madeand to an improved and simplified clutch mechanism for controlling-the speed changes of the die.

()ur invention also relates to certain ar' rangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

i drive;

.A preferred form of our invention is shown in the drawings in which Figure 1 is a side elevation of a portion of a lathe, with our improved threading mechanism attached thereto;

Fig. 2 is. a top plan view of the -mecha nism shown in Fig. l; i

Fig. 3 is a leit-hand end elevation, partly in section taken along the line 33 in Fig. 1

Fig. i is a front elevation of thedie spindie and associated parts, partly in section. and taken along the line 4.4 in Fig. 2;

Fig. 5 is a fr ontelevation of the detachable support fo:- the die controlling mechanism, and the parts carried thereby;

.Fig. 6 is a detail elevation. of the compound lever thrr ugh which the speed changes of the threading die are controlled, taken along the line 6--6 inFig. l; a l

Fig. 7 is a front elevation ofthe compound lever sho WninFig. 6;

Figg8 isa se( tional view taken along the line 88 in Fig. 4e, and showing the clutch mechanism for ihe low speed drive;

Fig. 9 .is a partial sectional view similar to Fig. 8, but showing the parts in a different position;

Fig. 10 is a sectionalview taken along the line 10-10 in Fig. 4, and showing the clutch mechanism for the high speed Fig. 11 is a partial sectional view similar to Fig. 10, but showing the parts in a dif ferent position, and

-Fig..12 is a detail sectional view along the line 1212 in Fig. 4.

Referring to ihe drawings we have indicated at 10-10 two of the rotatable spindles which support consecutive pieces of work W. These 'spindlesflare inoun-tedin a head 11 slidable on ways 12 formed on the bed 13 of th a machine. The movement of the head is controlled through connections, not shown. from a main cam shaft 14; rotatable in suitable hearings in the bed 13. The usual'box tools are mounted in a rigid tool head 15, ant. the threading die 16 is secured to-qa spindle 17 (Fig. 4) rotatable and s'lidab'le in i he toolhead 15.

At the left of the tool head 15 there is provided an additional fixed frame member 18 having guide ways 19 and 20 (Fig. 3) formed on the front face thereof. A support 21 (Figs. 3 and 5) is provided with-a dovetailed groore by means of which the support may be accurately positioned upon either guide way to correspond to the third or fourth positions of the work holding spin-' dles.

As shown in the drawings the support is mounted on the upper guide way or in the third position, but it may be readily removed therefrom and maybe replaced in the fourth position upon the guide way 20. Furthermore it is sometimes desirable to perform two successive threading operations in an automatic lathe, and for such purposes a separate support 21 with its attached mechanism may be mounted upon each of the guide ways 19 and 20, thus permitting the threading operations to be performed in both the third and fourth positions.

The mechanism mounted upon the support 21 is used for advancing and withdrawing the die relatively to the work, and also for controlling the speed changes of the die. For the purpose of positionmg the die axially arack sleeve 22 (Fig. 5) is slidably but nonrotatably mounted in a bearing 21 on the support 21. An intermediate shaft 23 is rotatable in a bearing 21 -on the support 21 and-a rod 230 fixed in said shaft extends freely through the sleeve 22 and is retained therein by a collar 231. V

A swivel connection is thus formed between the shaft 23 and the sleeve 22. The shaft 23 extends into a recess 170 (Fig. 4) formed in the end of the spindle 17 and is retained therein by a cross pin 232 which extends through slots 233 in the spindle 17. A spring 234 in the recess 170 holds the pin normally against the outer ends of the slots but permits the parts to yield when the threading die engages the work.

The rack teeth upon the sleeve 22 are positioned to engage a spur gear 24 mounted on a short shaft 25, rotatable in bearings in the support 21. A pinion 26 is secured to the outer end of the shaft 25 and meshes with a segment gear 27 pivoted upon a stud 28 secured to the support 21. The support 21 is fixed upon the frame member 18 by a number of bolts or studs 29 (Fig. 2).

A roll 30 (Figs. 2 and 5) is mounted in an arm 31 which is adjustable about the axis of the stud 28, and which ma be fixed to the segment gear 27 by means 0 a bolt32 extending through a segmental slot 33 formed in the gear. The roll 30 is positioned for engagement by a pawl or dog 34 (Fig. 2) pivoted in a block35, keyed to a sliding bar 36, and longitudinally adjustable thereon.

The bar 36 carries a series of pawls or dogs for controlling the operations'of the threading die when in the upper or third position, and a corresponding bar 37 is provided forsupporting the dogs which control the threading mechanism when in the fourth position. The bars'36 and 37 are slidable at their right-hand ends in bearings 38-38 6 (Fig. 1) formed on the side of the tool head 15. The bars also extend through a cross bar 39 to which each bar is rigidly secured. A third bar 40 is secured at one end to the center of the cross bar 39 and is slidable in a bearing 41 carried by the frame member 18. The bars 36 and 37 are thus supported for longitudinal reciprocation parallel to the axis of the threading die and the work holding spindles.

he cross bar 39 is connected by a link 42 to the upper end of an arm 43 keyed to a horizontal shaft 44 which is mounted in fixed hearings in the frame 13. A second arm 45 is secured to the shaft 44 between the sides of the frame and is provided with a cam roll 46 positioned to engage an irregular cam 47 mounted upon the main or cam shaft 14. This shaft 14 makes one complete revolution for each advance of the workholding spindles, and the sliding bars 36 and 37 are therefore given one full reciproca tion after each advance of the spindles to new positions.

As the bar 36 is moved to the right after the work W is positioned in front of the threading die 16, the pawl or dog 34 engages the roll 30 and partially rotates the segment gear 27, thereby advancing the rack sleeve 22, the shaft 23, the spindle 17 and the die 16. By the continued movement of the segment gear 27 the roll 30 is carried downward until the dog 34 passes freely over the roll.

T he parts are so timed that the advancing stock W will engage the die substantially at the moment when the roll 30 passes below the dog 34. At this instant the dog, being directly above the roll, is effective to prevent backward movement of the die, thus holding the die against the thrust of the work until the die begins to feed forward in its cutting movement, when the shaft 23 and sleeve 22 will be drawn forward by the die independently of the dog 34.

We will now describe the mechanism for rotating the die at suitable speeds to secure the cutting of the thread and the withdrawal of the die. A sleeve 50 (Fig. 4) is loosely mounted upon the intermediate shaft 23, but is prevented from free rotation thereon by a loose key or tumbler 51 (Fig. 8) whichclosely limits the relative an ular movement of the sleeve and shaft. he tumbler 51 is held within the sleeve 50 by a cap 50 (Fig. 4) which is extended to find a bearing in the head 15.

A high speed gear 52 normally rotates freely upon the outside of the sleeve 50, and a low speed gear 53 is also mounted for rotation concentric with the shaft 23 and sleeve 50. The gears 52 and 53 are constantly driven by gears 54 and 55 (Fig. 2) suitably connected with the driving mechanism of the machine, the proportions of the gears being tain the driving engagement such that the gear 52 willrotate at a speed greater than that of the work, while the gear 53 rotates at a speed less than that of the Work.

The operationof these gears during thread cutting is such that the gear 53 acts as a brake or retarding device to hold the die back so that the work will be turned into the die' during. the cutting operation, while the gear 52 drives the die ahead of the work, so that the die will be run off after the thread has been cut.

Under normal conditions the shaft 23 and the threading die are continuously rotated at slow speed by the gear 53. This gear is provided upon its inner surface with a series of ratchet teeth 56 (Fig. 8) positioned for engagement with a pawl 57 slidable outwardly in a recess in the sleeve 50. A light flat spring 58 forces the pawl yieldingly outwardly to engage. the ratchet teeth 56 and this spring is of suflicient stren th to mainlhetween the gear 53 and. the shaft-23 when no thread is being out; c

"As soon. as the die engages the stock it tends to rotate at the same speed as the stock, and therefore to run ahead of the gear 53 and the sleeve which is latched theretobythe pawl 57. Under these conditions the shaft 23 presses against the lower end of the tumbler 51 (as viewed in Fig. 8).

I I The tumbler, however, engages the sleeve 50 35 only at a point near the center of the tumbler, and the'pressure of the shaft 23 therefore acts throughthe tumbler 51 as a lever to'apositively holdthe pawl 57 in engagel'nent with the ratchet teeth 56. So long, as

the die is cutting, therefore, the gear 53 retards therotation of the die, and the pull of the. stock transmitted through the shaft23 and thetui'nbler .51 holds the pawl 57 in operative engagement withthe teeth 56.

After the thread has been cut to the de sired length it is necessary to connect the high speed gear tothe shaft 23 in order thatthe diemay be run off of the work.

' The gear-52 is provided with oppositely disposed ratchet teeth 60 (Fig. 10) and a slid. ing pawl 61is mounted in a recessin the sleeve 50. collar 62 (Fig. 4) is slidable uponthe shaft 23, said collar being formed. 0; When the pawl 61 entwo diameters. gages the smallerdiameter, as shown in 4: and 10, thehigh speed gear, is inoperativel. ,Wlien the collar is moved to the right so that its portion of larger diameter The sleeve '62 is slidably secured to the shaft 23 by a keypin 64; (Fig. 12) which engages a key way or slot 65 formed in the shaft At its left-hand end the sleeve 62 is provided with a flmge 62 fitting loosely within a pocket in a two part sleeve 66 slidable in a bearing fOIX'I'lGClOll the support 21. A stud67 (Fig. 3) carried by the sleeve 66 extends through a slot in the side of the bearing into position for engagement by a compound operating lever.

The compound levar comprises a member 70 (Fig. 7) pivoted at 71 to the support 21, and having a slotted engagement at its lower endwith the stud 67 At its upper end the member 70 is provided with a stud 72 which extends through a slot 73 in the second member 74 of the compound lever. The member 74 is made in two parts for purpose of adjustment and is pivoted at 75 to the support 21. This member has an en gaging portion 74A which extendsdownwardly into the pati of a dog 76 pivoted in a block 77, and adjustably secured to the sliding bar 36. i

\Ve have previously described the manner in which the die is. advanced by the dog 34 until it engages the stock. It is then drawn forward upon the st ock during the cutting operation, and at the same time the stock is advancing toward the left as viewed in the drawings. The dog 7 6 will be so adjusted that it will. engagethe portion 74 of the compound lever when substantially the desired'length of thread has been cut. Such engagement througlc the stud 67 and the sleeve 66 will slide the sleeve 62 to the right along the shaft 23, thus forcing outward the pawl 61 and or using driving engagement of the high speed gear 52. The die will then be rotated faster than thework WV with the result that it will be quickly run off of the work.

During this portion of the o gieration the sleeve 50 will. drive the shaft 23 instead of retarding the same, and thetumbler 51 will be moved .to the position shown in Fig. 9, thus releasing the pawl 57 which will thereafter snap lightly over the ratchet teeth 56,

being forced outward only by the light the work, a third dog 80 (Fig. pivoted in g a; block 8]. adjustable on the bar 36 engages a shoulder 27 a (Fig. 5) of the segn'ient gear 27 and partially rotates the gear in a direction opposite to that caused bythe en{. 'agement of the pawl 34 withthe roll 30. The sleeve 22v and shaft 23, and the spindle l7 arethus positively returned to their origi nal inoperative posit ions.

As the shaft 23 approaches its extreme. 'left-l'iandf positiont 1e key pin 64 (Figs. t and 12) reaches the end of the ,slot 65, and is thereafter moved a short distance to the left .ca-rryingwith it the sleeve 62, and'releasing the pawl 61, thereby disengaging the high speed g'eatr 52, and restoring the spindle 23 to the control of the low speed gear 53.

It will be noted that the entire operation thus far described has taken place during the continued movement of the bar 36 to the right. After these operations have been completed the bar 36 makes an idle stroke to the left in returning to initial position. The dogs 34, 76 and 80 are each yieldingly mounted in their supportin blocks so that they are inoperative on their return stroke. Suitable springs are provided for restoring the dogs to their operative positions before the beginning of the next movement to the right.

It is often necessary to cut a thread up to a shoulder which necessitates the stoppin of the die at a fixed point in its trave. For such operation We provide an auxiliary device for shifting the sleeves 66 and 62 through which the high speed gear is controlled. This auxiliary device comprises one or more pins 90 (Fig. 4) slidable in holes in the bearing 21 and positioned to engage the end of the sleeve 66. The opposite ends of the pins extend beyond the bearing into position for engagement by a collar 91 which may be clamped to the shaft 23 in any desired position. When the collar engages the pins 90 the motion of the shaft 23 will be transmitted directly to the sleeves 66 and 62, and the high speed pawl 61 will thus be forced positively outward at a fixed point in the travel of the shaft 23 and the die 16.

While this arrangement is more positive in its action than the compound leve'r pre-' viously described, the latter device is used wherever possible, as the compounding of the levers causes the sleeve 66 to move more rapidly than the shaft 23, and thus throws the pawl into operative position with less opportunity for Wear of the parts before driving engagement is established.

A collar 95 loosely encircles the sleeves 66 and 62 and holds the gear 52 in position upon the sleeve 50.

Whenwe desire to remove the threading mechanism or to change it to a different position, we first remove the cross pin 232 (Fig. 4), and the screws 29. The support 21, the sleeve 22 and actuating mechanism therefor, the shaft 23, the sleeves 62 and 66 and the collar 95 may then be removed as a unit. The sleeve 50, cap 50, and gears 52 and 53 may then be drawn out of the tool head 15 to the left (Fig. 4) and the spindle 17 and die 16 may be removed to the right. The parts can thereafter be reassembled in a different operatin position or they may be laid aside and t e usual fixed cutting tools may be substituted therefor.

Having thus described our invention it will be evident that changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of our invention as set forth in the claims, and we do not wish' to be other- Iwise limited to the details herein disclosed,

Whatwe do claim is:

1. In an automatic lathe, in combination, a threading die, driving means effective to rotate said die at each of two different speeds, controlling mechanism for said driving means, devices effective to advance and retract said die axially, actuators for said devices, and means to support said devices, mechanism, and actuators in alinement with either one of two successive operative posi; tions of the work spindle.

2. In an automatic lathe, in combination,

a threading die, means to rotate said die at each of two different speeds, a fixed frame member having guide-ways thereon, a removable support slidable on said ways, means to secure said support in fixed position on said ways during the continued operation of the machine, and mechanism mounted on said support through which the thread-cutting operation may be controlled.

3. In an automatic lathe, in combination, a threading die, means to rotate said die at each of two diflerent speeds, a fixed frame member having two sets of guide-ways thereon, a support adapted to be mounted in fixed position on either one of said sets of ways, mechanism mounted on said support through which the thread cutting operation may be controlled, and means to actuate said mechanism in either position thereof.

4. In an automatic lathe, in combination, a threading die, means to rotate said die at each of two different speeds, a fixed frame member having two sets of guide-ways thereon, a support adapted to be mounted in fixed position on either one of said sets of ways, mechanism mounted on said support through which the operation of the threada threading die, driving means for rotating said die at each of two different speeds, de-

vices connected to move said die axially,

and a single actuating member effective to advance and retract said die and to control the speed changes thereof.

6. In an automatic lathe, in combination, a threadin die, driving means effective to rotate the ie at each of two different speeds, a fixed frame member having guide-ways thereon, a support slidable on said ways, means to securesaid support in fixed posi named tionvon' said ways, a rack slidable in said support, a gear pivoted on said support and meshing with said rack, a segment gear on said support connected to turn said first ear, and actuating means movably mounte on said fixed frame for moving said segment gear in each direction.

'1 7. In an automatic lathe, in combination, a threading dle, a spindle through ,WlHCl'l said the is controlled, means to operate said spindle at each of two different speeds, a

fixed frame member having guide-ways slide said rack, a pawl effective to move said gear, rack and spindle in one direction, a second pawl. effective to move said parts in the opposite direction, and means to move saidpawls.

8. In an automatic lathe, in combination, a threading die, a spindle through which said die is controlled, means to operate said spindle at each of two different speeds, a fixed frame member having guide-ways thereon, a support slidable on said ways, means to secure said support in fixed position on said ways, a rack sleeve slidable in said support, a segment gear connected to slide said sleeve, a: bar mounted for positive longitudinal movement, a pawl on said bar effective to move said gear, sleeve and spindle in one direction, a second pawl on said bar eflective to move said parts in the opposite direction, and third pawl on said bar efiective to change the speed of rotation of the threading die.

9. In an automatic lathe, in combination, a threading die, a spindle through which said die is controlled, means to operate said spindle at each of two different speeds, a

fixed frame member having guide-ways thereon, a support slidable on said ways,

means to secure said support in fixed position on said ways, a rack sleeveslidable in said support, a segment gear connected to slide" said sleeve, a bar mounted for positive longitudinal movement, a pawl on said bar effective to move said gear and sleeve in one direction, a second'pawl on said bar effective to move said gear and sleeve in the opposite direction, and a third pawl on said bar effective to change the speed of rotation of the threading die, all of said pawls being operative during movement of said bar in one direction an being inoperative during the return movement of said bar.

10. In an automatic lathe, a threading die, means to rotate said die in the direction of rotation of the stock at either of two different speeds, mechanism for positioning and controlling said die, a bar slidable parallel to the axis of the die, and a series of pawls earriedby said bar and effective successively to advance said die, to increase the speed of rotation thereof, and to thereafter return said die to initial position and restore the original speed of rotation all duringa single cc ntinued travel'of the .sliding bar in one diirection.

11. In an autonatic lathe, a threading die, means to rotates tld die in the direction of rotation of the stock at either of two different speeds, mechanism for positioning and controllingszid die, a bar slidable parallel to the axis-of the die, a series ofpawls carried by said bar and effective to advance said die, to increase the speed of rotation thereof, and to thereafter return sa d die to initial position and restore the original speed 7 of rotation all during a single continued travel of the slicing bar in one direction, and cam-actuated means for giving said bar an irregular reciprocating motion.

12. In a; threading attachment, a die, a spindle to which said die is secured, low and high speed gears loosely rotatable concentric with said spindle, and pawl and ratchet mechanism by which either one of said gears may be rendered effective to control said spindle and die, said pawls being mounted on a sleeve loosely keyed to the spindle by a tumbler effective to cause positive engagement of the low speed pawl with its ratchet during the cutting ofthe thread.

13. In a threading attachment, a threading die, a spindle through which the die is controlled, a sleeve on said spindle, low and high speed gears rotatable outside of said sleeve, separate pawls slidable transversely in said sleeve to cause engagement of said gears with said sleeve, external adjustable mechanism for actuating the high speed pawl, and a device for forcing the low speed pawl into driving positionyieldingly when running idle and positively when cutting the thread.

14. In a threading attachment, a threading die, a spindle through which the rotation of the die is controlled, a sleeve on said spindle, a low speed gear rotatable concentric with said sleeve and having internal ratchet teeth, a pawl slidable transversely in said sleeve, a spring efi'ective to force said pawl lightly into engagement with said ratchet teeth, and a tumbler loosely confined in a r'ecessin said sleeve and engaging one end of said pawl, said spindle having a keyway therein loosely fitting said tumbler and permitting limited angular movement between said spindl e and sleeve, said tumbler acting as a lever when forced ahead by said spindle through engagement with the side of the keyway aiid being effective to force said pawl positively outward" to operatively engage said ratchet teeth.

15. In an autoi iatic lathe, in combination,

a threading die, driving means effective to rotate the die at each of two different speeds,

a fixed frame member, a support, means to secure said support in fixed position on said frame, a rack slidable in said support, a gear pivoted on said support and meshing with said rack, a segment gear on'said support connected to turn said first named gear, and actuating means movably mounted on said fixed frame for moving said segment gear in each direction. I

16. In an automatic lathe, in combination, a threading die, a spindle through which said die is controlled, means to operate said spindle at eachcof two different speeds, a

Copies 0! thin patent my be obtained for rack sleeve connected to said spindle, a segment gear connected to slide said sleeve, a bar mounted for positive longitudinal movement, a pawl on said bar effective to move said gear, sleeve and spindle in one direction, a second pawl on said bar efi'ectiveto move said parts in the opposite direction, and a third pav'vl on said bar eflective to change the speed of rotation of the threading die.

In testimony whereof we have hereunto set ourhands.

JAMES J. HOGAN. JOHN F. JUDD. LYMAN M. WAITE.

five cents each, by addressing the Commissioner of Patents, Washington, D 0.

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