US3149511A

US3149511A - Thread rolling heads

Info

Publication number: US3149511A
Application number: US72020A
Authority: US
Inventors: Warren Arthur Percy
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-11-28
Filing date: 1960-11-28
Publication date: 1964-09-22
Anticipated expiration: 1981-09-22

Description

Sept. 22, 1964 A. P. WARREN 3,149,511

THREAD ROLLING HEADS Filed Nov. 28, 1960 3 sheets-#sheet 1 ATTORNEY Sept. 22, 1964 A. P. WARREN 3,149,511

THREAD ROLLING HEADS Filed Nov. 28, 1960 3 Sheets-Sheet 2 ATTORNEY SePt- 22, 1964 A. P. WARREN 3,149,511

THREAD ROLLING HEADS Filed NV. 28, 1960 3 Sheets-Sheet 5 ArToRNEY United States Patent Office 3,lli9,5 l l Patented Sept. 22, 1954 3,149,5111 THREAD RGENG HEABS Arthur Percy Warren, 11 Share Ave., Chem, England Filed Nov. 28, 19%, Ser. No. 72,629 S Claims. (Cl. dll-6) This invention is concerned with improvements in and relating to screw threading devices.

There are known and in general use at the present time screw cutting dieheads of the type comprising a pair of relatively rotatable parts, an inner one of which is apertured to axially receive a blank to be screw threaded and is provided with equiangularly spaced radial slots extending from the aperture for receiving thread chasers, the outer one of the parts including outer cam tracks adapted to bear against and support the chasers in the radial slots and inner cam tracks adapted to engage the chasers in the slots and radially adjust the chasers in response to relative rotation of the parts, and means may be provided for effecting an adjustment of the parts such as to enable the chasers to be radially set to the correct cutting depth, and spring biasing means may be provided for effecting an automatic relative rotation of the parts at the end of a cutting stroke such as to move the chasers radially clear of the blank and thereby allow the head and the blank to be axially passed clear of each other.

It is an object of the present invention to enable a diehead of such a type to be used as a thread rolling head also.

The present invention accordingly provides a unit for enabling a cutting diehead of the type described to be used for rolling screwthreads comprising a set of carriers adapted to bear thread rolls, and an end plate, the carriers being constructed for tting into the radial slots in the inner part or" the diehead and for being engaged by the inner cam tracks of the outer part of the diehead and be thereby radially adjustable in the diehead, the carriers also being shaped so as to be radially supported for any radial position in the slots by the cam tracks of the outer part, the carriers each further including a portion adapted to extend outwardly of the head and carrying in that portion a thread roll, and the end plate being adapted to be releasably secured to the outer part and engage the extending portions of the carriers to thereby retain the cmriers in the diehead, the extending portions of the carriers and the end plate having similar cam tracks, the cam track of the end plate being adapted to cooperate with the carriers at their cam tracks and the tracks being such that the end plate thereby provides an additional radial support for the carriers for any angular position or" the carriers in their slots.

In order that the present invention can be well understood there will now be described one embodiment thereof, given by way of example only, reference being had to the drawings accompanying the provisional specication in which:

FIGURES l and 2 are side and end views respectively of a screw cutting diehead with its chaser retaining end plate removed;

FIGURE 3 is a section view taken along the line El* lll of FIGURE 1;

FIGURES 4 and 5 are section views taken along the lines lV-IV and V-V respectively of FIGURE 3;

FIGURES 6, 7 and 8 are side, end and inverted plan views respectively of a carrier bearinU a cylindrical thread roll;

FIGURES 9 and l0 are side and end views respectively of an end plate for retaining carriers constructed as shown in FIGURES 6, 7 and 8 in the diehead;

FIGURES 1l, l2 and 13 are side, end and inverted plan views of a guide member, and

FIGURE 14- is an end View of the diehead tted with carriers constructed as shown in FIGURES 6, 7 and 8.

Referring to FIGURES l to 5, the diehead comprises a cylindrical body 1, a cylindrical cam part 2 rotatably mounted on the body, an adjuster head 3 and a shank 4.

The body comprises a flanged head 5 extending from a shank 6. An aperture 7 in the body allows a blank to be passed therethrough and the body is further provided With equiangularly spaced radial slots 8 extending radially outwardly from the aperture into the r'langed head, the radial slots being adapted to receive at die chasers 6i? as shown in FIG. 3.

The cylindrical cam part comprises a sleeve 9 carrying an aunulus 1). The sleeve is provided With outer cam racks l1, and has a anged rear face 12 engaging a shoulder 1.3 or" the body. A handle 14 is coupled to the sleeve.

The annulus is fitted around the body for rotation with the cam part and so that inner cam tracks in the form of projections 16 on its front face are presented to the backs of the radial slots in the body as shown in FIGS. 2 and 3. The projections are adapted to engage recesses in the back faces of the die chasers 6) which are thereby engaged in the slots and will be moved radially in the slots upon the cylindrical cam part 2 rotating about the body. The outer cam tracks 11 serve to radially support the die chasers whatever may be their radial position in the slots. A dat end plate (not shown) serves to retain the chasers in the diehead, the plate being bolted to the front face or the body which is provided with threaded holes (not shown) for receiving the securing screws.

rcuate springs 17 are tted into a chamber 13, formed by the cylindrical cam part and the body, to bear at one end against stops 19 carried by the flange 12 and at the other end against stops Ztl carried by the body, the springs biasing the cam part in a clockwise direction (as viewed in FGURE 4) relative to the body.

The body shank has a keyed sliding fit into a anged member 21 of the adjuster head, the body being spring biased rearwardly towards the adjuster head (the biasing means not being shown) so that the flange 12 enters a recess 22 in the ilanged member as shown in FIG. 3 and a recess 23 in the flange 12. receives the head 24 of a detent pin 24. The detent pin which is biased towards the flange 12 by a spring 25 is carried in a bush 26 secured to an adjuster ring 27. This ring is threaded at 21S to the flanged member to lie within the recess 22. An adjuster screw 29 (see FIGS. 1 and 2) is iitted to the hanged member to so bear against the bush that movement of the screwr will cause the bush to move in an arcuate slot provided in a head 30 of the anged member, the bush rotating together with the adjuster ring about the threaded part 2S and in so doing moving the detent pin head which will engage with the flange to rotate the cam part 2 about the body 1. Graduations 31 on the sleeve and a datum mark 32 in the periphery of the anged member (see FIG. l) enable the degree of rotation to be set to a predetermined amount. Rotation of the adjuster ring in a clockwise direction (as viewed in FIGURE 5) is eiected against the bias of a spring 33 lying in a recess in the adjuster ring to bear at one end against a projection 34 formed on the ring and at the other end against a stop 35 carried by the llanged member 21.

The cylindrical cam part 2 can be set to either one of two angular positions relative to the body by rotating the detent pin 24 about its axis by means of a handle 36 to bring either of two cam surfaces formed on the head of the detent pin into engagement with the flange 12.

The flanged member 21 is secured by four screws (not shown) to a flange 37 extending from the shank 4, the

a shank being provided to enable the holder to be coupled to a suitable carrier, such for example as the head of a turret lathe.

A conversion unit according to the present invention for enabling the diehead to be used as a thread rolling head includes a plurality of thread roll carriers 38, there being four in the present embodiment as shown in FIG- URES 6, 7 and 8. Each carrier is comprised of a roll carrier block which includes a rear part 39 adapted to fit into the body slots 8. Each block has a recess 4l) in its rear face formed to receive and engageone of the projections .16. Extending from the rear part so as to project outwardly of the body 1 is a front part 41 which is of a greater thickness than the rear part and includes a recess 42 from which extend apertures 43, provided for receiving a spindle 44 of a thread roll 45. The thread rolls have `a profile comprising parallel ribs and therefore the proles of each roll are set back relative to the p-rotiles of the neighbouring roll in the direction of threading by a distance equal to a quarter of the pitch, and the apertures are inclined to the axis of the carrier yat the angle of the thread helix to be formed. The front and rear parts of each thread roll carrier both include an arcuate side 46 and the front part is stepped at 47, an arcuate side 48 extending forwardly thereof being of similar form to the arcuate side 46.

The conversion unit also includes an end plate 49, as shown in FIG. 9, adapted to retain the carriers in the. head. The end plate is of annular form, is stepped at 50 and has on one radially inwardly directed face came surfaces 51 of similar form and dimensions to the cam surfaces 11 and on the other radially inwardly directed face cam surfaces 52 also of similar form to the cam surfaces 11.

The diehead is modiiied, in order that the end plate- 49 may be secured to it, by the provision of threaded holes formed in the front face of the sleeve 9 as shown in FIG. 3, the end plate being provided with four counterbored apertures 53 in line with the threaded holes 1 whereby the end plate can be bolted to the sleeve.

With the conversion unit fitted to the diehead in place of the die chasers Gti and their retaining plate, it will be appreciated that relative rotation of the sleeve 9 and the cylindrical body 1 will move the thread roll carriers 3S radially in their slots in a similar fashion to the die chasers. Furthermore the end plate 49 will move with the sleeve and hence provide an additionalvsupport and location for the front parts of the roll carriers for all radial positions of the carriers in the body slots S.

Should it be found that the size of the rolls is such that the rolls foul one another, as when threads are being rolled on a small diameter workpiece blank, then two diammetrically opposite roll carriers 38 are removed and two guide members 65 as shown in FIGURES l1, l2 and 13 inserted in their place. Guide members 65 are of somewhat similar form to the roll carriers, but instead of having a recess in which the rolls are carried, the front part of the guide members is extended downwardly at 54 and an inwardly curved recess 55 formed in the extension so that in operation the curved part will bear on the blank being threaded in advance of the rolls, thereby acting as a guide or steady.

In operation, with the thread roll carriers 38 secured in the diehead (as shown in FIGURE 14) and the holder shank 4 tted for example to the head of a turret lathe, j

the cylindrical cam part 2 and annulus 10 are rotated in an anticlockwise direction (as viewed in FIGURE 4) about the cylindrical body 1 until the head 24 of the detent pin engages with the recess 23 in the flange 12. The thread rolls 45 will be moved radially inwardly during such rotation into a thread forming position. 'Ihe detent pin 24 is then set to either one of its two angular positions to regulate the thread depth. The diehead then is advanced axially towards a rotating blank carried by the lathe until the blank is engaged by the thread roll profiles whence the thread rolls, together with their carriers and the holder, will be advanced along the blank to form a thread in the blank periphery, the blank passing into the central aperture 7 of the body 1. At the end of a thread forming stroke the turret head is restrained against furher axial movement, but the rolls 45 will continue to advance due to the relative rotation between the rolls and the blank. The rolls carry with them the cylindrical cam part 2 and the body 1 until the sleeve recess 23 disengages from thed etent pin head 24 when; thereafter the cam part will rotate in a clockwise directionras viewed in FIGURE 4 under the bias of the springs 17 thereby moving the roll carriers 38 radially outwardly in their slots so that the rolls are moved clear of the blank. The thread roll head can them be traversed clear of the blank and the thread rolls can then be reset to the cutting position.

I claim:

l. In a conversion unit for converting apparatus for cutting threads into apparatus for rolling threads wherein the thread cutting apparatus includes a body member and a cam part rotatably mounted on the body member, the body member defining a blank receiving aperture and a plurality of radial slots extending from the blank receiving aperture, each of the radial slots being adapted to receive a thread cutting die Chaser, the cam part defining an outer cam track individually positioned adjacent each radial slot and adapted to cooperate with the end of a thread cutting die chaser to provide radial support for the thread cutting die chasers when the thread cutting die chasers are radially positioned within the slots in response to relative rotation between the cam part and the body member, the combination comprising:

(a) a plurality of 'thread roll carriers, each carrier having a rear portion adapted to fit into one of the radial slots in the body member, a front portion extending outwardly from the body member and an arcuate side,

(b) a thread roll rotatably mounted on the side of each of the thread roll carriers opposite to the arcuate side thereof and adjacent the blank receiving aperture when the carrier is in the radial slot in the body,` the thread roll being adjacent the front portion so that at least a portion of each thread roll is disposed outwardly from the body member,

(c) an end plate adapted to be releasably secured to the cam part and extending outwardly from the body member to enclose at least a portion of the thread roll carriers, the end plate defining an outer cam surface associated with the outer cam track of the cam part for engaging the arcuate sides of the thread roll carriers to radially support the thread roll carriers in any predetermined radial position, and

(d) the arcuate side of each of the thread roll carriers being arranged to engage the outer cam track of the cam part and the cam surface of the end plate whereby the thread roll carriers may be radially supported within the slots in response to relative rotation between the cam part and the body member.

2. A conversion unit according to claim 1 wherein:

(a) the end plate is stepped and the arcuate side of each thread roll carrier adapted to engage the outer cam surface delined by the end plate is stepped, the step of the end plate engaging the step of each thread roll carrier, and

(b) the outer cam surface dened by the end plate is similar to the outer cam track dened by the cam part and is adapted to engage the stepped portion of the arcuate side of each thread roll carrier remote from the body.

3. A conversion unit according to claim 1 including at least one guide member in place of a thread roll carrier, the guide member being formed identical to the thread roll carrier except that the side adjacent the blank holding aperture is substantially hat, not carrying a thread roll, and includes a downwardly extending portion adjacent the front portion which defines an inwardly curved recess adapted to bear upon a blank being engaged by the remaining thread rolls, thereby acting as a guide or steady.

4. A thread rolling head, comprising:

(a) a diehead of the class including a body member and a cam part rotatably mounted on the body member, the body member defining a blank receiving aperture and a plurality of radial slots extending from the blank receiving aperture, each of the radial slots being adapted to receive a thread cutting die chaser, the cam part defining an outer cam track individually positioned adjacent each radial slot and adapted to cooperate with the end of a die chaser to provide radial support for the die chasers when the die chasers are radially positioned within the slots in response to relative rotation between the cam part and the body member,

(b) a plurality of thread roll carriers, each carrier having a rear portion adapted to lit into one of the radial slots in the body member, a front portion extending outwardly from the body member and an arcuate side,

(c) a thread roll rotatably mounted on the side of each .of the thread roll carriers opposite to the arcuate side thereof and adjacent the blank receiving aperture when the carrier is in the radial slot in the body, the thread roll being adjacent the front portion so that at least a portion of each thread roll is disposed outwardly from the body member,

(d) an end plate adapted to be releasably secured to the cam part and extending outwardly from the body member to enclose at least a portion of the thread roll carriers, the end plate defining an outer cam surface associated with the outer cam track of the cam part for engaging the arcuate sides of the thread roll carriers to radially support the thread roll carriers in any predetermined radial position, and

(e) the arcuate side of each thread roll carrier being arranged to engage the outer cam track of the cam part and the cam surface of the end plate whereby the thread roll carriers may be radially supported within the slots in response to relative rotation between the cam part and the body member.

5. ln a conversion unit for converting apparatus for cutting threads into apparatus for rolling threads wherein the thread cutting apparatus includes a body member and a cam part rotatably mounted on the body member, the body member defining a blank receiving aperture and a plurality of radial slots extending from the blank receiving aperture, each of the radial slots extending from the blank receiving aperture, each of the radial slots being adapted to receive a thread cutting die chaser, the cam part deiining an outer cam track individually positioned adjacent the end of each radial slot remote from the blank receiving aperture adapted to cooperate with the end of a die chaser to provide radial support for the die chasers when the die chasers are radially positioned within the slots in response to relative rotation between the cam part and the body member, means carried by the cam part defining an inner cam track adapted to engage guide surfaces on the die chasers for radially positioning the thread chasers in the slots, the combination comprising:

(n) a plurality of thread roll carriers, each carrier having a rear portion adapted to t into one of the radial slots in the body member, a front portion extending outwardly from the body member and an arcuate side,

(b) the rear portion of each thread roll carrier delining a guide surface adapted to engage the inner Cam track for radially positioning the thread roll carrier in the slot,

(c) a thread roll rotatably mounted on the side of each of the thread roll carriers opposite the arcuate side thereof and adjacent the blank receiving aperture when the carrier is in the radial slot in the body, the

thread roll being adjacent the front portion so that at least a portion of each thread roll is disposed outwardly from the body member,

(d) an end plate adapted to be releasably secured to 'the cam part and extending outwardly from the body member to enclose at least a portion of the thread roll carriers, the end plate defining an outer cam surface associated with the outer cam track of the cam part for engaging the arcuate sides of the thread roll carriers to radially support the thread roll carriers in any predetermined radial position, and

(e) the arcuate side of each of the thread roll carriers being arranged to engage the outer cam track of the cam part and the cam surface of the end plate whereby the thread roll carriers may be radially supported within the slots in response-to relative rotation between the cam part and the body member.

6. A thread rolling head, comprising:

(a) a diehead of the class including a body member and a cam part rotatably mounted on the body member, the body member defining a blank receiving aperture and a plurality of radial slots extending from the blank receiving aperture, each of the radial slots being adapted to receive a thread cutting die chaser, the cam part defining an outer cam track individually positioned adjacent each radial slot and adapted to cooperate with the end of a die chaser to provide radial support for the die chasers when the die chasers are radially positioned within the slots in response to relative rotation between the cam part and the body member, means carried by the cam part dening an inner cam track adapted to engage guide surfaces on the die chasers for radially positioning the thread chasers in the slots,

(b) a plurality of thread roll carriers, each carrier having a rear portion adapted to nt into one of the radial slots in the body member, a front portion extending outwardly from the body member and an arcuate side,

(c) a thread roll rotatably mounted on the side of each of the thread roll carriers opposite to the arcuate side thereof and adjacent the blank receiving aperture when the carrier is in the radial slot in tl e body, the thread roll being adjacent the front portion so that at least a portion of each thread roll is disposed outwardly from the body member,

(e) the arcuate side of each of the thread roll carriers being arranged to engage the outer cam track of the cam part and the cam surface of the end plate whereby the thread roll carriers may be radially supported Within 'the slots in response to relative rotation between the cam part and the body member.

7. A thread roll carrier having utility in a conversion unit for converting a thread cutting apparatus into a thread rolling apparatus, the thread cutting apparatus including a body member and a cam part rotatably mounted on the body member, the body member being substantially axially bored to receive a workpiece blank to be threaded and defining a plurality of radial slots extending from the bore, each of 'the radial slots being adapted to receive a thread cutting die chaser, the cam part defining an outer cam track having portions individually disposed adjacent the outer extent of each radial slot and adapted to cooperate with the end of a die chaser to provide radial support for the die chaser when the die chasers are radially positioned within the slots in response to relative rotation between the cam part and the body member, the

i conversion unit including an end plate releasably mountable to the body member and adapted for maintaining the thread roll carrier in operative relation to the body member, the thread roll carrier comprising:

(a) a roll carrier block having a rst side and a rear portion adapted to tit into one of the body member radial slots so that the irst side of the block is disposed adjacent the body member bore,

(b) the roll carrier block further having a second side disposed opposite the block from the first side and a front portion disposed outwardly from the body member relative to the body member bore when the carrier block is engaged in said body member slot, and

(c) a thread roll rotatably mounted to the block in the front portion thereof so that at least a portion of the thread roll is disposed outwardly of the first side from the block and so that the thread roll is substantially aligned with the body member bore,

(d) the second side ofthe block being arcuately curved for mating engagement with a cooperating portion ofthe outer cam track and with a cam surface defined by the end plate of coniiguration substantially the same as said portion of the outer cam track for radially supporting the carrier in the slot.

8. A thread roll and carrier therefor comprising an elongated roll carrier member having a rear portion and a front portion adjacent substantially parallel front and rear ends of the member and rst and second substantially parallel sides substantially normal to the ends, the rear portion of the member having a thickness normal to the ends and sides less than the front portion so that the rear portion is adapted for engagement in a thread cutting die chaser slot of a diehead, the second side of the member being stepped toward the irst side in the front portion of the member, the second side forwardly and rearwardly of the step dening a pair of substantially identical convex substantially cylindrical surfaces, the front portion defining a recess opening to the rst side, a thread roll disposed in the recess so that a portion of the roll extends beyond 'the rst side, and means for mounting the roll to the member for rotation about an axis askew to the elongate extent of the member.

References Cited in the tile of this patent UNITED STATES PATENTS 401,600 Sternbergh Apr. 16, 1889 1,085,643 Tewksbury Feb. 3, 1914 1,639,028 Eden Apr. 25, 1924 2,704,950 Scott June 14, 1951 FOREIGN PATENTS 711,759 Great Britain July 7, 1954

Claims

1. IN A CONVERSION UNIT FOR CONVERTING APPARATUS FOR CUTTING THREADS INTO APPARATUS FOR ROLLING THREADS WHEREIN THE THREAD CUTTING APPARATUS INCLUDES A BODY MEMBER AND A CAM PART ROTATABLY MOUNTED ON THE BODY MEMBER, THE BODY MEMBER DEFINING A BLANK RECEIVING APERTURE AND A PLURALITY OF RADIAL SLOTS EXTENDING FROM THE BLANK RECEIVING APERTURE, EACH OF THE RADIAL SLOTS BEING ADAPTED TO RECEIVE A THREAD CUTTING DIE CHASER, THE CAM PART DEFINING AN OUTER CAM TRACK INDIVIDUALLY POSITIONED ADJACENT EACH RADIAL SLOT AND ADAPTED TO COOPERATE WITH THE END OF A THREAD CUTTING DIE CHASER TO PROVIDE RADIAL SUPPORT FOR THE THREAD CUTTING DIE CHASERS WHEN THE THREAD CUTTING DIE CHASERS ARE RADIALLY POSITIONED WITHIN THE SLOTS IN RESPONSE TO RELATIVE ROTATION BETWEEN THE CAM PART AND THE BODY MEMBER, THE COMBINATION COMPRISING: (A) A PLURALITY OF THREAD ROLL CARRIERS, EACH CARRIER HAVING A REAR PORTION ADAPTED TO FIT INTO ONE OF THE RADIAL SLOTS IN THE BODY MEMBER, A FRONT PORTION EXTENDING OUTWARDLY FROM THE BODY MEMBER AND AN ARCUATE SIDE, (B) A THREAD ROLL ROTATABLY MOUNTED ON THE SIDE OF EACH OF THE THREAD ROLL CARRIERS OPPOSITE TO THE ARCUATE SIDE THEREOF AND ADJACENT THE BLANK RECEIVING APERTURE WHEN THE CARRIER IS IN THE RADIAL SLOT IN THE BODY, THE THREAD ROLL BEING ADJACENT THE FRONT PORTION SO THAT AT LEAST A PORTION OF EACH THREAD ROLL IS DISPOSED OUTWARDLY FROM THE BODY MEMBER, (C) AN END PLATE ADAPTED TO BE RELEASABLY SECURED TO THE CAM PART AND EXTENDING OUTWARDLY FROM THE BODY MEMBER TO ENCLOSE AT LEAST A PORTION OF THE THREAD ROLL CARRIERS, THE END PLATE DEFINING AN OUTER CAM SURFACE ASSOCIATED WITH THE OUTER CAM TRACK OF THE CAM PART FOR ENGAGING THE ARCUATE SIDES OF THE THREAD ROLL CARRIERS TO RADIALLY SUPPORT THE THREAD ROLL CARRIERS IN ANY PREDETERMINED RADIAL POSITION, AND (D) THE ARCUATE SIDE OF EACH OF THE THREAD ROLL CARRIERS BEING ARRANGED TO ENGAGE THE OUTER CAM TRACK OF THE CAM PART AND THE CAM SURFACE OF THE END PLATE WHEREBY THE THREAD ROLL CARRIERS MAY BE RADIALLY SUPPORTED WITHIN THE SLOTS IN RESPONSE TO RELATIVE ROTATION BETWEEN THE CAM PART AND THE BODY MEMBER.