US3353390A

US3353390A - Synchronized thread rolling tool

Info

Publication number: US3353390A
Application number: US410205A
Authority: US
Inventors: Bruce D Bedker
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-11-10
Filing date: 1964-11-10
Publication date: 1967-11-21
Anticipated expiration: 1984-11-21

Description

Nov. 21, 1967 5.0. BEDKER SYNCHRONIZED THREAD ROLLING TOOL Filed Nov. 10, 1964 INVENTOR' o 'BRU BEDKER FIG.4

A T TORNEVS United States Patent Ofiice 3,353,390 Patented Nov. 21, 1967 3,353,390 SYNCHRONIZED THREAD ROLLING TOOL Bruce D. Bedker, Mount Clemens, Mich, assignor to Leo W. Bedker, Detroit, Mich. Filed Nov. 10, 1964, Ser. No. 410,205

' 3 Claims. (Cl. 72104) The present invention relates to a synchronized thread rolling tool or attachment of the type illustrated and described in US. Letters Patent 2,701,484 of Feb. 8, 1955, to Leo W. Bedker. The invention of that patent addresses itself to an improvement in thread rolling and related rolling apparatus, in accordance with which a pair of forming rolls, upon initially engaging a rotating workpiece in directions transverse of the axis of the latter, are permitted to have a slight degree of relative differential movement, or relative angular phase shift, about the respective roll axes, being positively gear-connected to thereafter rotate together in exact angular phase relation under a drive from the workpiece. Thus, the initial differential of movement permits the threading or other forming rolls to bring their working formations into exactly timed synchronism, so as to track properly with threading or the like progressively formed by them as the rolls are advanced toward the workpiece axis.

In the patent referred to above, the desired result was attained by providing for a slight lost motion in the driving connection between a gear and one of the forming rolls, also in providinga mount for the holder head for the rolls which permits one roll to engage the workpiece slightly before engagement of the latter by the other roll. In accordance with the present invention, the same principle of allowing for a corrective lost motion is followed. That is, provision is made that one of the forming rolls will be the first of the two to engage the rotating workpiece and be driven thereby; yet the second roll will be driven positively, prior to engaging the workpiece and after lost motion has been practically instantaneously taken up in gearing interconnecting the rolls, until it, too, contacts the workpiece. After this, the workpiece takes over the drive of the forming rolls, without regard to the gearing. In addition, means are also provided to effect a micro-adjustment in the angular relationship of the rolls to insure that they will be in exactly phased relation when rolling commences. Such means may also introduce a change in depth of intermesh at the teeth of certain gear members which drivingly interconnect the forming rolls, but full driving capacity is retained until the roll set has contacted the workpiece, after which the latter drives the rolls in a true tracking relationship.

While reference is herein made to thread rolling equipment, it will be evident to those skilled in the art that the tool or attachment of the present invention is, like that of the Bedker patent, equally well suited to knurling, to the formation of splines by rolling, etc., in all of which a slight error in relative angularity or phase relation of a pair of rolls upon engaging a workpiece may, unless compensated or corrected, result in damage to the gearing and, at best, the production of inacceptable work.

It is a general object of the invention to provide an improved rolling tool or attachment of the sort described, characterized by a pair of forming rolls rotatable on a bifurcated mounting head on parallel, laterally spaced axes and having meshing gear means for the positive rotational drive thereof, as driven by a rotating workpiece in which the desired phase adjustment of the rolls is made possible by providing for an adjusting bodily shift of a pinion of a meshing spur gear train which drivingly interconnects the rolls. The adjustment permits a variation in the distance of the pinion axis from the axes of gears meshed by the pinion, i.e., a shift of the pinion in a direction approximately normal to a theoretical line through the gear axes. Thus, considering one of the gears to be a driver rotated by the workpiece and driving the other through the adjustable pinion, the machinist may make a very fine, micrometgr-like corrective adjustment of the position of the latter, such as will bring the gears, and the forming rolls gear-connected thereto, into an exactly phased relationship necessary for proper tracking of the rolls in fully engaging and rolling the piece.

It is seen that should the rolls be out of exactly proper angular coordination at the instant of attack on the workpiece, for example, to the extent of a fraction of the width of a pinion or gear tooth, consequently of an intended rolled workpiece formation, such as might result in the marring of or rolling of double the intended thread formations on the workpiece, the possible fractional error is corrected by the adjustable pinion provisions of the invention.

It is a further object of the invention to provide a rolling tool operating on the general principle of adjusting the pinion axis-to-gear axis distance described above, in which the micro-adjustment to provide the desired phase correction, one set up, is thereafter rigidly and precisely maintained throughout the production run, without further change.

More specifically, the invention provides a rotatable eccentric (on which the interconnecting drive pinion is journaled) for shifting the latter bodily relative to the remainder of the gear train drivingly interconnecting the thread forming rolls, plus frictional anchor means for thereafter locking the eccentric and pinion against bodily departure from the desired setting. In this matter of locking the setting, the invention provides an annular locking flange on a manually rotatable eccentric-carrying member, which flange is concentric with the axis of rotative adjustment of the member and is adapted to be strongly held frictionally against an outer wall face of the attachment to lock the adjusted setting.

In further accordance with the invention, the provisions for effecting the desired adjustment are all readily and conveniently accessible from the exterior of the tool or attachment, without the need for removing the latter from an operating mount, for example, the tool slide of an automatic screw machine. Furthermore, the arrangements of the improved tool are such as to make it very easily assembled and dismantled.

The foregoing as well as other objects will become more apparent as this description proceeds, especially when considered in connection with the accompanying drawings illustrating the invention, wherein:

FIG. 1 is a perspective view illustrating the improved threading or rolling tool of the invention;

FIG. 2 is a fragmentary view in horizontal section on the plane 2-2 of FIG. 1;

FIG. 3 is a view in vertical section along line 3-3 of FIG. 2, showing a workpiece in successive positions of engagement with the forming rolls of the attachment or tool, including a solid line position upon initial contact engagement with a workpiece, and the dotted line position upon substantial completion of the rolling operation;

FIG. 4 is a fragmentary view similar to FIG. 3, illustrating various adjusted positions of the inter-connecting pinion of the tool (solid and dotted lines); and

FIG. 5 is a fragmentary view in vertical section along line 55 of FIG. 2.

As indicated above, the invention deals with the general type of rolling tool in which, if the forming rolls were positively geared together for coordinated drive without rolling of a workpiece would be impossible, and gear tooth breakage might take place if the rolls were simultaneously engaged.

As hereinafter further described, and as described in detail in the Bedker patent identified above, the difliculty arises because of the fact that, as the tool is advanced toward the rotating workpiece, its two forming rolls, in initially contacting the piece are subjected to a frictional effort, even if the latter is rotatively stationary, tending to rotate the rolls in opposite directions. On the other hand, the dynamic frictional effect of the rotating workpiece upon the rolls is in a common angular direction of rotation of the latter.

Consequently, in the case of one thread roll the effect of the two forces, i.e., essentially static frictional and rotatively driving, is additive, while in the case of the other thread roll it is subtractive; and it is this differential which requires compensation or correction by the relative differential rotation of the two rolls in coming into engagement with the rotating workpiece, to permit the rolling formations of the rolls to come into the exact desired angular relationship for proper tracking with the workpiece. The matter will be further dealt with in connection with FIG. 3 of the drawings.

The improved tool is generally designated by the reference numeral 10. It comprises a block-like head 12 of bifurcated shape, which head is in general constituted by upright front and rear housing members 13, 14, respectively, between which the forming

rolls

16, 17 are received, being journaled on parallel horizontal shafts or

axles

18, 19, respectively, by the head members 13 and 14. Suitable provisions are made to adjust the lateral spacing of the

rolls

16, 17 relative to one another. For example, the shaft 19 may be mounted in eccentric bushing devices 20 for a relatively coarse lateral adjustment, and the shaft 18 may be sustained in elongated slots 21 for a relatively fine, final adjustment, and held therein by a set screw 22, in the manner illustrated and described in the patent to Leo W. Bedker 3,110,202 of Nov. 12, 1963. The invention does not concern these provisions.

As shown in FIG. 3, the thread or like forming

rolls

16, 17 are adapted to be driven, respectively, by relatively

small diameter gears

24, 25 in fixed angular, coaxial relation thereto, which gears mesh downwardly with

larger diameter gears

26, 27, respectively, journaled on rods or shafts 28 which are borne in horizontal spaced, parallel relation to one another by tool head 12; and the

gears

26, 27 are drivingly interconnected by a small diameter pinion 29 in adjustable mesh therewith in accordance with the invention.

As shown in FIG. 1, the gear shafts 28 are held in place by screw means 31 taking into their ends from the exterior of the front head member 13; and the head 12 is also provided with a bottom dovetail formation 33 for mating reception in a similar shaped formation on a tool slide (not shown), by means of which the tool or attachment is adapted to be advanced toward and retracted away from a rotating workpiece W (FIG. 3). Typically, this slide will be a slide of a conventional type of automatic screw machine.

The tool head 12 is also equipped with other provisions not germane to the present invention, for example, adjusting screw means at 34 by which the axial position of the attachment on the tool slide may be adjusted and maintained, further screw means 35, and the like.

Before detailing the structural improvements of the invention, it may be pointed out that, reference being had to FIG. 3 of the drawings, even if the workpiece W were rotatably fixed, an upward movement of the tool 10 into initial contact with the piece would cause frictional forces to be exerted on the

rolls

16, 17 tending to rotate the roll 17 clockwise in the direction of the dotted line arrow (left-hand side of roll 17 in FIG, 3) and the roll 16 in the opposite, counterclockwise direction (dotted line arrow to the left of roll 16); and this effect exists also in the case of roll 16 when the workpiece W is rotating and driving the rolls, for example, in the direction of the arrow applied to the workpiece in FIG. 3.

On the other hand, as the

rolls

16, 17 continue to be dynamically engaged and driven by the rotating Workpiece in moving from the solid line relationship with the latter in FIG. 3 to the dotted center line relationship at or possibly beyond a horizontal plane through the roll axes, the effect on

rolls

16, 17 is to rotate the latter in the same angular direction, i.e., counterclockwise, per the solid line arrows applied to the rolls. Thus, the resultant eifect, in the case of the roll 17 is the difference between the two forces, while the resultant effect on the roll 16 is the addition of the two forces; and it follows that, unless compensated, the

rolls

16, 17 will have differential rotation in advancing in rolling engagement with the workpiece, with destructive effect on the gearing, or, in any event, a substantial failure of the rolling formations on the rolls to track the workpiece properly as rolling proceeds. Bedker Patent 2,701,484 shows means to make the necessary compensation, but further means may be required to further correct the roll phasing for truly precise tracking.

To the end of making such correction very accurately, the tool 10 provides for the use of an improved adjustable mount for the intermeshing pinion 29 which is generally designated by the reference numeral 37. This device comprises a rotatable adjusting member 38 having a cylindrical, eccentric-carrying barrel 39 which is mounted to rotate on a horizontal axis in a journal opening 40 formed through the front head member 13 of the tool, a very close tolerance being observed. Outwardly of the upright wall face of member 13, the barrel 39 is provided with an integral annular locking flange 42, which substantially overlies the outer face of the member surrounding the opening 40; and still further outwardly, the barrel 29 of device 37 is provided with a knurled fingerpiece 43.

The barrel 39 is provided with an axial bore 45 extending through the center thereof and well beyond its rear; and this bore receives a locking screw or stem 46, the end of which is formed at 47 for threading engagement in a tapped bore 48 of the rear member 14 of the tool head 12. The unthreaded body portion of stem 46 is received in an outer counterbore 48' of bore 48, and an axial clearance of the stem at 46 permits axial movement thereof in the counterbore 48' when the stem is threadedly taken up. This has the effect of clamping the flange 42 of fingerpiece 43 against the face of house member 13, and thus locking barrel 39 in an adjusted position.

The journaling barrel portion is provided with an operating eccentric 50 of cylindrical shape to the rear of its own cylinder formation; and the drive transmitting pinion 29 is journaled on eccentric 50 for operating rotation about an axis eccentric of journal barrel 39. Split ring means, generally designated by the reference numeral 52, surround the screw or stem 46 directly to the rear of pinion 29, holding the latter in fixed axial relation to the stem as the pinion and barrel assembly moves axially upon threaded taking up or loosening of the stem.

As shown in FIG. 5, the barrel member 39 is provided, directly behind its locking flange 42, with a radially extending stop pin 54 receivable in an arcuate slot 55 opening outwardly through the forward face of head member 13 and radially inwardly of the barrel members journal opening or bore 40. Thus, with the screw or stem 46 loosened somewhat, the fingerpiece 43 may be manipulated to a limited extent in either angular direction, correspondingly shifting the eccentric 50, and the pinion 29 journaled thereon, about the axis of stem 46. The latter can then be retightened to lock the pinion axis in the adjusted position, the lock flange 42 taking firm frictional engagement with the outer face of head member 13 for this purpose. If desired, screw or stem 46 may be further backed off to bring the flange to the dotted line position of FIG. 2, whereupon the pin 54 may be axially cleared from arcuate slot 55, enabling a greater degree of angular adjustment. However, it is the more limited adjustment of the eccentric and pinion 29 with which the invention is primarily concerned.

The outer face of head member :13 is appropriately calibrated at 57 (FIGS. 1 and for coaction with an indicator marking 58 of lock flange 42.

FIG. 3 shows a typical adjustment of the eccentric 50 to bring the pinion 29 into a less-than-full or perfect meshing engagement with the intermediate gear 26, which is the consequence of a shift of the axis of the eccentric (hence of the pinion) in a direction approximately normal to a theoretical line through the axes of

gears

26 and 27. FIG. 4 of the drawings shows, in solid line, an other position with the pinion 29 closer to said theoretical line of the gear axes and a consequent full and complete meshing engagement of the teeth of pinion 29 with those of both of the

intermediate gears

26, 27. This is the In setting (FIGS. 1 and 5). It is seen from FIG. 4 that a full permissible rotation of barrel 39, upon loosening of the screw of stem 46, will have the effect of shifting the eccentric and pinion, on the path of the doubleheaded arrow A in FIG. 4, away from the fully engaged relationship of the tooth members to the Out setting. Micrometer-like intermediate settings are available.

In any position of adjustment in this range of shift, it will be appreciated that, considering the roll 16 as a driver rotated by workpiece W and acting through

gears

24, 26 and pinion 29 to drive gear-

s

27, 25 and roll 17, the rolls may be phase-adjusted in a very fine manner, i.e., to an extent representing a small fraction of the width of a tooth (and of a rolled formation) or representing a whole width or more. Hence in this manner the invention may also serve the function of the structure shown in the Bedker patent first identified above.

Despite some change in depth of tooth intermesh occasioned by the bodily pinion shift, the pinion and gear teeth remain amply engaged for a positive transmission of rotative thrust through the gearing between the

rolls

16, 17, once the slight lost motion upon the formers engaging the workpiece has been absorbed, to rotate the latter in precise synchronism up until the time that the workpiece assumes the drive.

It is seen in FIGS. 1 and 2 that the pinion adjusting device 37 is fully accessible from the exterior of the tool and it is not necessary to remove the latter from the tool slide to make the desired adjustment. Upon making the same, retightening of stem 46 clamps the eccentric 20 tightly in adjustable position, and maintains that adjustment through the entirety of production. In general, the manipulations involved in the use of the tool 10 are positive in nature, requiring no attention after the making of an original setting for the production run.

Broadly considered, the invention alfords means to provide for the precise adjustment of phasing of the rotation of the forming rolls upon engagement with the work, by means of a micrometer or coarser adjustment of a component of spur type gear means which drivingly interconnects the rolls, and thereafter maintaining the adjustment.

What I claim as my invention is:

1. In a rolling tool of the type having a pair of forming rolls engageable with a rotating workpiece in a plane paralleling a plane substantially including the axes of said rolls, pairs of meshing gears drivingly connected to the respective rolls, and pinion having meshing engagement with and drivingly connecting a gear of each pair with another, the improvement to adjust the distance from the axis of said pinion to the axes of at least one pair of said gears for a precisely phased drive of the rolls, comprising means mounting said pinion for movement transverse of a theoretical line through the gear axes, said tool having a head by which said rolls, gears and pinion are supported for rotation, said mounting means comprising an eccentric member journaled for adjusting rotation on said head on an axis paralleling the gear axes, said pinion being journaled by said eccentric member for rotation on an axis laterally spaced from and paralleling said eccentric member axis.

2. In a rolling tool of the type having a pair of forming rolls engageable with a rotating workpiece in a plane paralleling a plane substantially including the axes of said rolls, pairs of meshing gears drivingly connected to the respective rolls, and a pinion having meshing engagement with and drivingly connecting a gear of each pair with one another, the improvement to adjust the distance from the axis of said pinion to the axes of at least one pair of said gears for a precisely phased drive of the rolls, comprising means mounting said pinion for movement transverse of a theoretical line through the gear axes, and means to lock said mounting means against movement from an adjusted position, said tool having a head by Which said rolls, gears and pinion are supported for rotation, said mounting means comprising an eccentric member journaled for adjusting rotation on said head on an axis paralleling the gear axes, said pinion being journaled by said eccentric member for rotation on an axis laterally spaced from said paralleling said eccentric member axis.

3. In a rolling tool of the type having a pair of forming rolls engageable with a rotating workpiece in a plane paralleling a plane substantially including the axes of said rolls, pairs of meshing gears drivingly connected to the respective rolls, and a pinion having meshing engagement with and drivingly connecting a gear of each pair with one another, the improvement to adjust the distance from the axis of said pinion to the axes of at least one pair of said gears for a precisely phased drive of the rolls, comprising means mounting said pinion for movement transverse of a theoretical line through the gear axes, and means to lock said mounting means against movement from an adjusted position, said tool having a head by which said rolls, gears and pinion are supported for rotation, said mounting means comprising an eccentric member journaled for adjusting rotation on said head on an axis paralleling the gear axes, said pinion being journaled by said eccentric member for rotation on an axis laterally spaced from and paralleling said eccentric member axis, said locking means including a part in fixed relation to said eccentric member, and :means to fixedly engage said part against a portion of said head in an adjusted position of the eccentric member.

References Cited UNITED STATES PATENTS 1,359,572 11/1920 Brennan 72104 3,110,202 11/1963 Bedker 72104 FRANCIS S. HUSAR, Primary Examiner.

Claims

1. IN A ROLLING TOOL OF THE TYPE HAVING A PAIR OF FORMING ROLLS ENGAGEABLE WITH A ROTATING WORKPIECE IN A PLANE PARALLELING A PLANE SUBSTANTIALLY INCLUDING THE AXES OF SAID ROLLS, PAIRS OF MESHING GEARS DRIVINGLY CONNECTED TO THE RESPECTIVE ROLLS, AND PINION HAVING MESHING ENGAGEMENT WITH SAID DRIVINGLY CONNECTED A GEAR OF EACH PAIR WITH ANOTHER, THE IMPROVEMENT TO ADJUST THE DISTANCE FROM THE AXIS OF SAID PINION TO THE AXIS OF AT LEAST ONE PAIR OF SAID GEARS FOR A PRECISELY PHASED DRIVE TO THE ROLLS, TRANSPRISING MEANS MOUNTING SAID PINION FOR MOVEMENT TRANSVERSE TO A THEORETICAL LINE THROUGH THE GEAR AXES, SAID TOOL HAVING A HEAD BY WHICH SAID ROLLS, GEARS AND PINON ARE SUPPORTED FOR ROTATION, SAID MOUNTING MEANS COMPRISING AN ECCENTRIC MEMBER JOURNALED FOR ADJUSTING ROTATION ON SAID HEAD ON AN AXIS PARALLELING THE GEAR AXES, SAID PINION BEING JOURNALED BY SAID ECCENTRIC MEMBER FOR ROTATION ON AN AXIS LATERALLY SPACED FROM AND PARALLELING SAID ECCENTRIC MEMBER AXIS.