US2218574A - Appliance for rolling screw threads - Google Patents

Description

G. GOULD APPLIANCE FOR ROLLING SCREW THREADS Filed Jan 10, 1940 3 Sheets-Sheet l INVENTOR GEORGE GOULD %MZm ATTORNEY Oct. 22. 1940." GO LD 2 218,574

APPLIANCE FOR ROLLING SCREW THREADS Filed Jan. 10, 1940 I 3 Sheets-Sheet 2 N R GEORGE GOULD ,ATTORNE Y V v FL-In" 0ct. 22. 1940. I r G. GOULD I 2,218,574

APIPLIANCEEOR ROLLING SCREW THREADS Filed Jan. 10, 1940 5' Sheets-Sheep s GEORGE GOULD BY wflfla ATTQEEEY- Patented Oct. 22 194) APPLIANCE FoRfRoLLmo scmiw THREADS I I George Gould, Birmingham, England, assignor to Wolseley-Motors Limited, Birmingham, England Application January 10, 1940, SerialNo. 313,199 y Great Britain November 24, 1939 1 10 Claims. (01. 80-;6)

This invention relates to tools or appliances for rolling screw threads on revolving work-pieces, being of the kind comprising a plurality of threaded rolls rotatably mounted upon a holder or support and adapted to-be engaged with the work so as toroll a screw thread'in the surface thereof. Thread-rolling tools'or appliances of the above kind are described and claimed in my application No. 285,546.

When the work-piece is of smalldlameter-the applied pressure of the threading rolls'tends to force the said work-piece'laterally out of position. There is difficulty in using a'rigid stop device for supporting the work against such displacement, as it is usual for that part of the work on which the thread is required, to be initiallyformed'to a diameter which is substantially that of the pitch diameter of the finished thread, the rolling operation causing the diameter to increase up to that of the finished thread; and it isnecessary for the stop to allow for such increase.

' The object of the present invention is to provide, in a thread-rolling tool or applianceof the kind referred to, a stop device, for positively sup-, v

porting the work against lateral displacement, which is automatically varied in its location as the diameter of the work'increases, wherebylt' will maintain an effective support forthe work throughout the threading operation.

According to the invention, a tool or appliance, of the kind referred to, for rolling screw threads,

includes a rigid stop or'steady device for engaging r I I the construction described in my application No;

the work and for supporting it against lateral displacement, and means operated by the traverse of the-threading rolls across the work for automatically varying the position of said stop 'or steady device, as-the diameter of the work -in-'-.

creases, whereby it willmaintain an effective support for the work throughout the threading op'erv t screw thread tdbe rolled thereon, and for this 4o ation.- 1 r I The invention will be more clearly understood as the specification proceeds and when taken in conjunction with theaccompanying drawings which illustrate a preferred embodiment thereof;

a It will be. understood, however, that this description and illustration are given by way of example only andnot by way of limitation. The invention may lend itself to a variety ofexpressions within thescope of the appended claims. .1 u

ance in accordance with thepresent invention,

showing the threading rolls just completing the threading ofthe work. i

Figure 2 is a side elevation,

'ure 2,

An adjustable screw'3l carried by the lower part Figure 3 isa cross-section on line III-III, Figure 2, showing the threading rolls about to commence the threading operation. Figure 4 is a cross-section on line IV-IV, Figure 2; Figure '5'is a cross section on line 'V-V, Fig- Figure 6 represents a horizontal section on line fVI-'-VI, Figure 1. V a

Figure '7 is a front elevation, and Figure 8 is a side elevation of the stationary holder or body part of the tool.

Figure 9 is a fron't elevationjand Figure 10 is: aside elevation of the lever carrying the steady device. 3 A 15 Figure 11 is a side elevation, and

Figure 12 is a front elevation ofthe swingin yframe'that carries the threading-roll block;

Referringto the said drawings, the improved tool or appliance comprises a stationary holder or body part 1 provided at its rear with a projecting shank 2' by which it can be fixed in the turret of a lathe or the like; a'laterally swinging frame or j lever 3 freely pivoted at its upper end upon a' horizontalpin 4 projecting from the frontface of the holder |;ja threading-roll'carrier' or block 5 pivoted within the frame 3 upon a horizontal pin 6 carried between the sides thereof; and a lever I mounted upon the pin! and carrying asteady or thrust roller 8 for supporting the work-piece 9 during the threading'operation. I 7

The threading-roll block 5 is substantially of 2 85,546, the same supporting a pair of verticallyspaced horizontal' pins I 0, I 0, mounted to revolve in spaced side: cheeks ll of the block and rigidly carrying-threadingrollsVIZ, l2. Theblock 5 is adapted to be moved'laterally'to press the rolls I2 against the revolving work 9-in order to cause a purpose-a suitablepart on the cross-slide of the machine (not shown) is arranged to'engage the 'back of the frame 3 which carries the block 5, the

a stop" screw I6 carried by the side of the body part land passing through a slot l1 in'the frame '3', restrictsthe outward movement of said'frarne' f i and'block 5 under the influence of the springs I4.

of frame 3 and co-operating with the bar l5, serve to limit the inward movement of the frame 3, being adjusted so as to arrest the traverse of the rolls |2 across the work after the termination of the threading operation, namely, as soon as the axes of the said rolls and the axis of the work-piece 9 lie in the same plane, as indicated in Figure l. i

The work-piece is supported against lateral displacement during the threadin operation by the steady or thrust roller 8 on lever I hereinbefore referred to, the said roller being freely mounted upon a pin I8 supported between jaws I9, I9, of the lever. As the work-piece-is initially a plain rod having a diameter equal to that of the pitch diameter of the finished thread, the diameter of the said work-piece will increase as the rolling operation progresses, and provision is therefore made for automatically adjusting the position of the roller 8 throughout the threading operation, so that it will at all times maintain an effectivesupport for the work and allow for the progressive increase in the diameter. To achieve this result, one end of the roller pin |8 projects beyond the side of the jaw |9 which is adjacent he holder or body part I and on this projecting end a roller 20 is freely mounted. The correspondingfront face of the holder I is formed with a vertical guide-way 2| having a lateral recess or housing 22 thatreceives the roller 20, and in the guide-way 2| is a sliding abutment bar 23 having, opposite to theroller 20, a tapered recess 24 the sloping surface of which forms. an abutment for the said roller. The lower end of the bar 23 is bevelled or mitred at 25 and engages the similarly bevelledor mitred inner end 26 of a horizontal slide 21 mounted in a horizontal guide-way 28 in the lower part of holder A spring 29 in the upper part of the guide-way 2| acts upon the bar 23 in order normally to lower it so that the upper portion of the inclined surface of recess 24 is opposite to the roller 20, said portion of the surface maintaining the roller close to the work at the commencement of the threading operation. The swinging-frame 3 carries, at its lower part, an adjustable thrust screw 30 which, at the commencement of the threading operation, just engages the outer end of the'horizontal slide 21 while the roller 20 is engaging the upper end of the tapered recess 24. As the threading-roll block moves inwards duringthe threading operation, the screw 30 on frame 3 progressively thrusts the slide 2! inwards, the co-operation of the bevelled surfaces 25, 26, causing the abutment bar 23 to be correspondingly raised and progressively bringing a deeper portion of the recess 24 opposite to the roller 20, thus permitting the steady roller 8 to move outwards to an extent corresponding to the increase in the overall radius of the work-piece 9. At all times the tapered surface of recess 24 maintains a positive support for the work piece as the diameter of the latter increases. 'Ihe"v amount of movement of the sliding abutment bar 23 and the degree of taper of the recess 24 are designed to allow an outward movement of steady roller 8 which corresponds throughout the threading operation with the increase in diameter of the work-piece.

At the conclusion of the operation the sliding abutment bar 23 and the slide 27 are returned to their initial positions by the action of the spring 29. A cover plate 36 serves to retain the bar 23 and slide 2! in their guide-ways.

In the arrangement described, the tool is de- 2 rolls against the revolving work-piece, the operation being completed when the stop 3| engages the bar 5. While the tool described is arranged for mounting in a turret machine the invention is not confined to tools for use in such machines.

As shown, the tool may embody the threadingroll locating means described and claimed in my application No. 285,546, the ends of the roll pins l0, l0, having V-shaped ends 32 engaged by V- shaped recesses 33, in the ends of levers 34 acted upon by springs 35.

I claim:

1. An appliance for rolling a screw thread on a work-piece comprising a roll support movable towards the work, a pair of spaced screwthreaded rolls rotatably mounted upon the support, a rigid steady device for engaging and supporting the work, and means operated by the traverse of the rolls across the work for automatically varying the position of said steady device, as the diameter of the work increases, whereby it will maintain an effective support for the work throughout the threading operation.

2. An appliance for rolling a screw thread on a work-piece comprising a stationary holder, a roll carrier movable relatively to said holder. a pair of spaced screw-threaded rolls rotatably mounted upon the carrier, a movable steady device for supporting the work against lateral displacement, a movable abutment mounted on the stationary holder for supporting the steady device against outward movement, and meansoperated by the movement of the roll carrierrelatively to the holder for automatically controlling the abutment so as to allow the steady device progressively to move outwards to an extent corresponding to the progressive increase in diameter of the work, whereby it will maintain an effective support for the said work throughout the threading operation. 7

3. An appliance for rolling a screw thread on a work-piece comprising a stationary holder, a

4. An appliance for rolling a screw thread on a work-piece comprising astationary holder, a roll carrier movable relatively to said holder, a pair of spaced screw-threaded rolls rotatably mounted upon the carrier, a movablesteady device for supporting the work against lateral displacement, an abutment slide guided in a vertical direction on the stationary holder and having a cam surface cooperating with the steady device, and means operated by the movement of the roll carrier relatively to the holder for moving said abutment slide to cause a different portion of the cam'surfac to co-operate with the steady device and thereby allow the latter to move outwards to an extent corresponding to the increase in the diameter of the work during the threading operation.

5. An appliance for rolling a screw thread on a work-piece comprising a stationary holder, a roll carrier movable relatively to said holder, a pair of spaced screw-threaded rolls rotatably mounted upon the carrier, a movable steady de vice for supporting the work against lateral displacement, an abutment slide movable in a vertical guldeway in the stationary holder and having a controlling recess in one side for co-operation with the steady device, a spring acting on the slide tending to depress it, and a transverse slide mounted in a guideway in the holder and operated by the movement of the roll carrier rela-- tively to the holder, the inner end of said transverse slide co-operating with the lower end of the vertical slide to cause the latter to be raised as said transverse slide ismoved inwards, whereby the steady device is allowed to move outwards to an extent corresponding to the increase in the diameter of the work during the threading operation. Y

6. An appliance for rolling a screw thread on a work-piece comprising a stationary holder, a roll carrier movable relatively to said holder, a pair of spaced screw-threaded rolls rotatably mounted 7 upon the carrier, a lever pivoted upon the stationary holder for movement towards and away 'from the work, a steady device carried by th lever for supporting the work against lateral displacement, a movable abutment mounted on the stationary holder and having a shaped controlling surface co-ope'rating with the steady device to support the latter against outward movement, and means operated by the movement of the roll carrier relatively to the holder for moving said abutment to cause a different portion of the con- 1 trolling surface to co-operate with the steady device as the threading operation proceeds,

7. An appliance for rolling-a screw thread on v a work-piece comprising a stationaryholder, a roll carrier movable relatively to said holder, a pair of spaced screw-threaded rolls rotatably mounted upon the carrier, a lever pivoted upon the stationary holder for movement towards and away from the work, a steady device carried by the lever for supporting the work against lateral displacement, an extension of the steady device projecting laterally from the. lever, a movable abutment mounted on the stationary holder and having a cam controlling surface co-operating with the extension, of the steady device to support the latter against outward movement, and means operated by the movement of the roll carrier relatively to the holder for moving said abutment to cause a difierentportion of the controlling surface to co-operate with said extension of the steady device as the rolling operation proceeds.

- ,8. An appliance for rolling a screw thread on a work-piece comprising a stationary holder,,a roll carrier movable'relatively to said holder, a pair of spaced screw-threaded rolls rotatably mounted upon the carrier, a lever pivoted upon the stationary holder for movement towards and away from the work, a pin carriedby the lever and projecting laterally from the latter, a steady roller mounted on the pin for supporting thework against lateral displacement, an abutment slide guided on the stationary holder and having a cam surface co-operating with, the projecting end 5 the pin, and'means operated by the movement of the roll carrier relatively to the holder for moving said abutment slide to cause a different portion'of the cam surface to co-operate with the said pin and thereby allow the steady roller to I move outwards to an extent corresponding to the increase'in the diameter of the work during the threading operation. 1 I

9. An appliance for rolling a screw thread on a work-piece comprising a stationary holder, a swinging lever hinged at its upper end to the holder for movement towards and away from the work, a roll carrier pivoted to said lever, a pair of spaced screw-threaded rolls rotatably mounted upon the carrier, a second lever pivoted upon the holder, a steady device on the said second lever for-supporting the work against lateral displacement, a movable abutment on the holder for supporting the steady device against outward movement, and means actuated by the swinging. lever for automatically operating the abutment so as to allow the steady device progressively to move outwards to an extent corresponding to the progressive increase in diameter of the work.'

, upon the carrier, a second lever pivoted upon the holder, a steady device 'on the said second lever for supporting the work against lateral displacement, an abutment slide movable in a vertical guideway in the stationary holder and having a controlling cam surface for co-operation with the steady device, a spring acting on the slide to depress it, a transverse slide mounted in a guideway in, theholder and co-operatingwith the vertical slide'to cause upward movement of the latter when pressed inwards, a projecting part carried by the swinging lever which, when the threading rolls engage the work, exerts pressure on the transverse slide to cause the vertical slide to move upwards andallow the steady device to move outwards as the threading operation progresses. I

r GEORGE GOULD.

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