US2662430A

US2662430A - Thread rolling apparatus

Info

Publication number: US2662430A
Application number: US147066A
Authority: US
Inventors: Fray Victor Hill
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-03-01
Filing date: 1950-03-01
Publication date: 1953-12-15
Anticipated expiration: 1970-12-15

Description

V. H. FRAY THREAD ROLLING APPARATUS 2 Shets-Sheet 1 Filed March l, 1956 llllllllllll i lllllll INVENTOR. y crmfi I ALL a (3 1 wax Dec. 15, 1953 v. H. FRAY 5 9 THREAD ROLLING APPARATUS Filed March 1, 1950 2 Sheets-Sheet 2 IN V EN TOR.

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Patented err. 15, 1953 NITED STATES EATENT THREAD ROLLING APPARATUS Victor Hill Fray, Auckland, New Zcaland Application March 1, 1950, Serial No. 147,066

(Cl. Ell-=7) Claims. 1

This invention relates to 'hread rolling apparatus whereby screw threads are formed by a rolling process on blanks of metal thread screws, bolts and the like, the objects of the present invention being the provision of improved thread rolling apparatus which will very appreciably speed up the forming or the rolled threads on the blanks.

At present, the threads are formed or rolled on blanks between fiat which have forming threads out in. their adjacent races, one plate stationary while the other is moved reciprocally above the other, one hlanl: at a time passing between these plates so that for one stroke of the movable plate one blank has the thread roiled thereon, the movable plate having to then return to starting position before the next blank admitted for the rolling of the thread thereon.

While the fiat plate reciprocally operated type thread rolling apparatus is that whic is in has not coins into general use even though demany years because of not being positive consistent enough in its action, this known roller type of apparatus rolling the thread one blank at a time.

is well known that in most forms of apparagreater speeds of operation are obtainable when movement is rotary as against reciprocating and therefore my invention has been devised for the purpose of speeding up production in the thread rolling operation by the provision of improvements in the rotary type of apparatus which will enable several blanks to be progressively roll threaded in the machine at the one time.

Broadly the invention comprises improvements in thread rolling apparatus of the type in which the threaded periphery of a rotatable thread roller is di posed adjacent to the threaded curved of a stationary segment with a gap between the roller periphery and. the threaded curved through which the blanks pass, wherein means are provided for feeding the blanks into such gap which are capable of being advanced or retarded while the machine is in operation in or er that such blanks be entered to the gap inlet at the instant when a thread start of the roller is in correct register with a thread start of the segment.

In describing the invention, reference will be made to the accompanying drawings in which:

Figure 1 shows an elevation of the improved thread roller apparatus,

Figure 2 is a plan view of Fl 1 with part or the upper bearing broken away to show the thread roller and. segment below same,

Figure 3 is a side elevation of Figure 4 is an enlarged sectional elevation of the blank feed timing mechanism,

Figure 5 is a plan View of the bosses with Figure 6 is a cross so @1021 of the spindle xtension, and

Figure *7 is a side elevation of the mechanism to show the spiral slots in the sleeve and the engagement of the boss pins ther with.

In the invention, the known apparatus prises a "tical spindle I with the i r gidly secured thereto an inounteal in bean ings 3 and i which extend from the vertical upw rdly extending portion 5 of a main frame 0 head portion E3 which is rigidly secured to a base plate or like i, provision being made as by gearing or the like (not shown) for drive of this spindle i and the roller 2 secured thereon, portion or the periphery of the roller 2 being clisposed closely adjacent to the curved face of a stationary segment t which adjustahly and slightly eccentrically mounted to the vertical portion 5 of the main frame 5 to leave a gap is (see Fig. 2) between the roller 2 the segment 8, the curved race to of the segment 8 be provided with the forming threads which are complementary to the forming threads in the periphery of the thread roller 2, means being provided to enter the blanks to the gap inlet to or feed-in end. of the gap 5.

To such known apparatus the improvements of the present invention are applied and. the improved mechanism is such as to enable several blanks it to be in the machine at the one time, progressively having the rolled threads applied thereto.

This is made possible because of the forming threads in the thread roller 5: having positions at the edge which are called thread starts thus a thread roller for say one inch screws may have as many as 32 starts, this nurnber of starts becoming less in respect of larger diametcred screws having less uhreads per inch.

Accordingly, that portion of the periphery oi the thread roller 2 which is adjacent to the stationary segment may have say 6 starts and it would therefore be possible to have 5 blanks pa s lo th c n t at the one time with a supply of the blanks 5L fed into the gap in a continuous stream from hopper-feed apparatus (not shown) with mechanism feeding the blanks it into the gap at the correct time for register of a start of the roller 2 with the start of the segment 3.

Now this obtaining of correct register is of extreme importance in that even a minute inaccuracy results in the rolled thread being of incorrect form, it having been found that even a change of revolutions from moderate to high can result in a time lag in operation of the mechanism which will result in the rolled thread being defective.

To obtain this accuracy by an original setting of the machine has been found to be unsatisfactory and therefore mechanism has been devised so that while the machine is running at its working speed under working conditions, adjustments can be effected and at any time when inaccuracy occurs, it can be immediately remedied with the machine continuing to operate.

The roller spindle I is provided with an extension la of smaller diameter extending up from its top end, such spindle extension la being diametrically split substantially from top to bottom and also having a bore II extending from substantially top to bottom thereof so that in effect there are two oppositely disposed slots I2 and i211 along the length of the spindle extension I :1 opening into the bore I I therein (see Fig. 6).

The top end of this spindle extension I a has a short thread 13 (see Fig. i) with a nut I4 screwed on to same so that the split portions cannot spread outwardly, inward spring being prevented by a short bush l5 secured in the end of the spindle bore II, a bore I511 in such bush slidably receiving an operating spindle I8 which extends down within the bore II and also extends to above the top of the spindle extension la to have a spool or the like I! secured at its top end.

Rotatably and neatly fitting over the spindle extension Ia between its bottom end and the nut M at the top thereof there is a sleeve I8 and secured to the bottom end of such sleeve I8 there is an indexing ratchet wheel I9, the sleeve I8 having two

slots

28 and 20a cut therein (see Fig. 7) at opposite sides thereof which

slots

20 and 20a are of long spiral form, being at only a slight angle in relation to the axis of the sleeve I8.

The operating spindle I5 passing down within the bore I I in the spindle extension la is slightly reduced in diameter IGa at its lower portion and on such lower reduced portion I60! two bosses 2| and 2Ia are slidable between the upper shoulder Itb as presented by the reduction in diameter and two locking nuts 22 on a thread 60 at the extreme bottom end of the spindle reduction IEa, a compression spring 23 on the spindle being disposed between these bosses 2! and 2m and tending to keep them bearing against the shoulder Ifib and the nuts 22 respectively.

These two bosses 2E and Zla (see Fig. 5) each have two pins iiib extending therefrom diametrically opposite and such pins 2 lb extend through the slots E2 and I2a in the roller spindle extension Ia (see Fig. 4) into the

spiral slots

20 and 20a in the sleeve l8 and while the roller spindle slots I2 and I2a are just wide enough to permit passage of the pins 2Ib, the

spiral slots

20 and 20a are appreciably wider, with the result that one pin 2Ib in a slot 20 or Ziia bears against one side thereof while the other pin 2 lb bears against the other side of the same slot, the action of the compression spring 23 being to cause these pins 2Ib to apply some pressure against their respective sides of the spiral slots 2% and 20a.

In effect therefore, these pairs of pins 2 Ib projecting into the opposite

spiral slots

20 and 20a of the sleeve I3 are acting as keys whereby drive of the roller spindle extension Ia is imparted to the sleeve l8 and the ratchet wheel I9 mounted thereon, but as these pins 2 lb can be moved up or down the spindle extension Ia by these movements being imparted to the spool I1, any such movements of the pins 2Ib because of being engaged in the spiral slots 20 and 29a will cause advancing or retarding movements of the sleeve I8 and the ratchet wheel I9 in relation to the roller spindle I.

The spool I? at the top end of the operating spindle I6 is engaged by the forked end 24a of an operating arm 25, the other end of this arm having a boss 24b which is vertically slidable within a tubular screw housing 25 which is secured to extend vertically up from the main frame 6, this screw housing 25 having a screw 26 which is rotatable therein by the turning of a handwheel 2'! secured at the top projecting end thereof, the screw 25 screwing through a threaded bore in the boss 2%, there being a slot 23 in the housing 25 through which this arm 24 passes from its boss 24b.

The indexing ratchet wheel I9 may have (if so desired) the same number of teeth therein as the number of thread starts of the thread roller 2, or may have half this number of starts, and disposed to engage this ratchet wheel I9 where is a pawl 29 mounted on the upper end of a pecker spindle 38, such vertical pecker spindle being supported in a bearing block 3| which is secured to the main frame 6 and at its bottom end has a lever arm 32 secured thereto (see Fig.

2) to the end of which a connecting rod 33 is pivotally connected, this connecting rod 33 being adjustable as to length and being connected to the pecker 34, such pecker 34 being in the form of a narrow blade disposed vertically on edge and being slidable through a guide block 35 so as to project its free end towards the feed-in end of the gap 9 between the roller 2 and the segment 8, a strong spring 36 such as of wound type as shown in Fig. 1 being engaged between the bearing block SI and the lever arm 32 and tending to hold the pawl 29 hard in engagement with the ratchet wheel I9.

A blank feeding chute 31 from the hopperfeed apparatus (not shown) brings the blanks I9 with their heads all uppermost to a position at the inlet end 9a of the gap 9, the movements of the pawl 29 as caused by the rotation of the ratchet wheel I9 and the spring 36 causing the pecker 3 to push the blanks IEI from the end of the chute 31 into the gap 9 one at a time at the correct instant when the register of a start of the roller I with a thread formation of the segment 8 takes place.

In use or operation, with the ratchet wheel I9 having the same number of teeth as the number of thread starts in the thread roller 2, the pecker 35 will be moved to push a blank Ii! into the gap 9 every time a thread start of the roller 2 is in correct register with the thread formation at the leading end of the stationary segment 8 at the gap inlet end to and therefore with a thread roller 2 having 32 starts and a ratchet wheel 32 teeth, 32 blanks I6 will pass through the gap 9 per revolution of the roller 2, although it will be understood that of this number there may be only say six blanks IG within the gap 9 at any time, this being determined by what proportion of a circle the sttaionary segment 8 represents.

aceasso accordingly, the blanks it are rolled from end to end of the gap 9 and as the stationary segment 3 is eccentrically mounted so that the gap 9 becomes narrower towards the discharge end thereof, the threads are gradually roll formed to the finished true shape.

if however there is not absolutely correctly timed entry of the blank ill to the gap 9 at the, time when there is register of a start on the roller with a start on the segment 8, it will be under stood that the threads formed at opposite sides or the blank it! by the roller 2 and the segment 8 are not in agreement or reg ster, and thus the one will build up a thread to be flattened or otherwise deformed by the other and when applying fine threads such as it per inch, a very small inaccuracy in the register results in the blanks being damaged and thus rendered useless.

With the blanks passing through the machine at high in many gross of the blanks being wasted, but with such small articles, it is important to keep the machine running and prevent stoppages for adjustments and this is the great benefit of the present invented apparatus.

ii the machine gets out of true adjustment as in fact does occur for reasons diflicult to locate and remedy, the handwheel Z'l is turned so that the screw is rotated to cause the operating arm d retarding being determined by close inof the thread of a blank which has just pas d through the machine.

Such movement of the operat ng arm 2 transmitted to the spool ll causes the operating spindle to be raised or lowered as the case may be within the bore ll of the spindle extension la and therefore presuming that it has moved down, this will cause its shoulder ltb to push down the upper boss 2! with its pins 2), such movement causing the compression spring 23 to be compressed to a further extent and causing a small movement, or slack to be obtained between the engaging pins 2 lb of the boss 2i and their respective engaged sides of the spiral slots 2%) and Ella in the sleeve is and then the movement being downward, the spring it pushes the lower boss 28c downward with the result that the pins 2th 7 of the respective bosses 2i and 22a again spread apart to their original distances, thereby again bearing at their respective engaging sides of the spiral slots rs and Eta.

Now this has had the effect of bringing the pins to bear in the spiral slots 2t and 2M at a slightly lower level and therefore, this has resulted in the sleeve l8 and its attached ratchet wheel it having been advanced slightly in position, this causing the pawl 29 to engage the bottom of the teeth slightly earlier so that the pecker it pushes the blanks iii into the slot or gap e that fraction of time advanced from previously which obtains the required register.

Upward travel of the operating spindle it will result in retarding movement of the ratchet wheel is and pecker 3d, the lower boss 2m and its pins being first to move in this case as being pulled upward by the locked nuts 22 and through the compression spring 23 pushing the upper boss 23 and its pins upward to again come to bear.

It has been found that with the machine driven by an electric motor having an ammeter on the power line, the load as indicated by such ammeter is lowest when there is correct register and in speed, any fault in register can soon result fact the obtaining of correct register can be obtained by efiecting the adjustments while noting the reading of the meter.

This therefore permits of the introduction of known electric alarm apparatus, the alarm bell or like being operated when the load exceeds the meter reading which indicates proper operation of the machine, or the introduction of known electric overload release apparatus which would switch off the motor to stop the machine or to stop the feed of blanks to the machine when same is unattended and a fault occurs.

I claim:

1. A thread rolling apparatus of the type in which a thread roller connected to a rotatable spindle has the threaded periphery of the roller provided with a plurality of thread starts disposed adjacent to the threaded curved face of a. stationary segment also having a plurality of thread starts so that there is a gap between the roller periphery and the threaded curved face of the segment in which gap a plurality of thread starts on the roller are simultaneously adjacent the segment and to which gap the blanks to be provided with threads are fed by a movable pecker member, the improvement which comprises an interconnecting or" said in vable pecker member with said rotatable spindle for moving the former in timed relationship with the latter including an extension to the roller spindle, opposite slots formed in such roller spindle extension and a bore extending down into said spindle extension, a short bush secured in the top of such bore and a nut at the top of the spindle extension, an operating sp;ndle slldable through the bush to extend down within the bore and to above the spindle extension with spool means secured at the top or" such operating spindle, a sleeve rotatable over the spindle extension with an indexing ratchet wheel secured thereto and opposite slots f long spiral form cut said sleeve, two bosses slidable within the spindle extension bore and over the lower portion of the operating spindle disposed within the latter, a shoulder to the operating spindle against which the upper boss bears and nuts at the bottom end of the operating spindle against which the lower boss bears, a compression spring between the bosses on the operating spindle and two pins extending from opposite sides of these two bosses passing through the slots formed in the roller spindle extension and moved into the spiral slots of the sleeve, a rotatably mounted pecker spindle, a pawl engaging the indexing ratchet wheel and mounted on the pecker spindle, a lever arm secured to the pecker spindle, a connecting rod effecting a connection between the lever arm and the movable pecker member, a guide block for such pecker member for guiding the free end thereof towards the feedin end of the gap between the thread roller and the threaded segment, spring means for holding the pawl hard in engagement with the indexing ratchet wheel, and means for slice-ting raising and lowering of the operating spindle to thereby advance or retard the action of said pecker mem her while the thread roller is rotating.

2. A thread rolling apparatus as claimed in claim 1 wherein the means for effecting the raising and lowering of the operating spindle comprise an operating arm one end of Whic' engages the spool at the top of the operating spindle while the other end has a boss which is slidable within a rigidly mounted tubular screw housing in which a screw is rotatable but not slidable, such screw being threaded to screw through the boss end of the operating arm.

3. A thread rolling apparatus comprising a vertical spindle with a thread roller rigidly secured thereto and mounted in bearings extending from the upwardly extending portion of a main frame or head which is secured to a baseplate, a stationary segment mounted to the main frame and having a threaded curved. face disposed eccentrically in relation to the thread roller with a gap between the threaded curved face and the adjacent portion of the roller, an extension to the roller spindle, opposite slots formed in such roller spindle extension and a bore extending down into said spindle extension, a short bush secured in the top of such bore and a nut at the top of the spindle extension, an operating spindle slidable through the bush to extend down within the bore and to above the spindle extension with spool means secured at the top of such operating spindle, a sleeve rotatable over the spindle extension with an indexing ratchet wheel secured thereto and opposite slots of long spiral form cut in said sleeve, two bosses slidable within the spindle extension bore and over the lower portion of the operating spindle disposed within the latter, a shoulder to the operating spindle against which the upper boss bears and nuts at the bottom end of the operating spindle against which the lower boss bears, a compression spring betveen the bosses on the operating spindle and two pins extendin from opposite sides of these two bosses passing through the slots formed in the roller spindle extension and into the spiral slots of the sleeve, a rotatably mounted pecker spindle, a pawl engaging the indexing ratchet wheel and mounted on the pecker spindle, a lever arm secured to the pecker spindle with a connecting rod effecting a connection between the lever arm and a pecker member, a guide block for such pecker member for guiding the free end thereof towards the feed-in of the gap between the thread rollers and the threaded segment, spring 111 ans for holding the pawl hard in engagement with the indexing ratchet wheel, and means for effecting raising and lowering of the operating spindle comprising an operating arm one end of which engages the spool at the top of the operating spindle while the other end has a boss which is slidable within a rigidly mounted tubular screw housing in which a screw is rotatable but not slldable, such screw being threaded to screw through the boss end of the operating arm.

4. A thread rolling apparatus comp-rising a frame, a continuously threaded cylindrical roller die having a plurality of threaded starts, means for rotatably supporting said roller die in said frame, a cooperating stationary die having an arcuate concave face having a plurality of thread starts, means for fixedly connecting said stationary die to said frame with said arcuate face disposed adjacent to said roller die with a gap therebetween through which blanks to be threaded pass, power means for rotating said roller die, a movable feed member carried by said frame for feeding blanks to be threaded into the gap between said roller die and said stationary die, two

movable members having surfaces inclined with respect to each other, means for operatively con necting one of said members to said power means for operatively connecting one of said members to said power means for driving said roller die, means for operatively connecting the other of said members to said feed member, means intermediate said relatively inclined surfaces and engaging the same for causing said members to move in unison, whereby said member connected to said feed member is driven upon movement of the other, moving means for adjustably moving said intermediate means relative to said inclined surfaces to effect displacement between said members, normally inactive adjusting means carried by said frame, and means connecting said adjusting means to said moving means, said last-named means being so constructed and arranged that said moving means may be operative or normally inactive during the thread rolling operation.

5. A thread rolling apparatus comprising a frame, a continuously threaded cylindrical roller die having a plurality of thread starts, means for rotatably supporting said roller die in said frame, a cooperating stationary die having an arcuate concave face having a plurality of thread starts, means for fixedly connecting said stationary die to said frame with said arcuate face disposed adjacent to said roller die with a gap therebetween through which blanks to be threaded pass, power means for rotating said roller die, a movable feed member carried by said frame for feeding blanks to be threaded into the gap between said roller die and said stationary die, two relatively rotatable members having surfaces in clined with respect to each other, means for operatively connecting one of said members to said power means for driving said roller die, means for operatively connecting the other of said members to said feed member, means intermediate said. relatively inclined surfaces and engaging the same for causing said members to rotate in unison, whereby one or" said members is driven upon rotation of the other, moving means for adjustably moving said intermediate VICTOR HILL PRAY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 412,682 Forsyth Oct. 1, 1889 1,571,232 Brennan Feb. 2, 1925 1,684,799 I Iochendorfer Sept. 18, 1923 2,065,066 Freter et al. Dec. 22, 1936 2,182,965 Unke 1. Dec. 12, 1939 2,464,833 Neumann Mar. 22, 1949