US3466918A - Profiling of workpieces - Google Patents

Description

Se t, 16, 1969 J. MARCOVITCH PROFILING OF WORKPIECES 3 Sheets-Sheet 1 Filed Sept. 24, 1965 M r m V m (A4000 MAAJCOV/ 766 Sept. 16, 69 J. MARc'ovncH 3,465,918

. PROFILING 0F woaxrmcms Filed Sept. 24, 1965 s Sheetsheet 2 46 Jacoa' Macaw rm p 1969 J. MARCOVITCH PRQFILING OF WORKPIECES 5 Sheets-Sheet 5 Filed Sept. 24. 1965 Him.

w w wmww kw H mwa r Mm 6 5 United States Patent 3,466,918 PROFILING 0F WORKPIECES Jacob Marcovitch, Johannesburg, Republic of South Africa, assignor to Rotary Profiles Anstalt, Vaduz, Liechtenstein Filed Sept. 24, 1965, Ser. No. 489,903 Claims priority, application Republic of South Africa, Sept. 30, 1964, 64/4,662 Int. Cl. B21b 1/16, 19/12; B21d 3/02 U.S. Cl. 72366 9 Claims ABSTRACT OF THE DISCLOSURE The disclosure relates to a method of rolling a workpiece that is a figure of revolution to reduce or profile it. The workpiece is nipped in a throat defined by two relatively moving bodies so that it is drawn through the throat, rotating about its axis as it does so; the bodies being forced towards each other to narrow the throat after the workpiece has been nipped in it, so to increase the reduction imposed on the workpiece without increasing the throat length.

This invention relates to the profiling of workpieces that are figures of revolution by passing them through a convergent throat having moving walls that nip the workpiece and drawn it into and through the throat. The throat is usually defined by two opposed rollers, at least one of which is rotated. The rollers may be side by side or one may be hollow and contain the other. Another arrangement is one in which the throat is defined by two opposed rectilinear surfaces that converge and which are mounted for relative oscillation.

Profiling of workpieces in this manner has considerable advantages over conventional machining methods, such as economy of material and speed of production. It has advantages, too, over profiling techniques which use two relatively movable rollers rotating at the same peripheral speed, that squeeze the workpiece between them, while rotating it but keeping its axis aligned with the axes of the rollers. These techniques require some means whereby the workpiece is maintained in position while it is being squeezed, and each workpiece must be individually brought into position, profiled and then withdrawn to make room for the next. Where the workpieces are nipped and drawn through a throat, a succession of workpieces can be made to follow one another through the throat, so that production is continuous. On the other hand, the technique of squeezing the workpiece between relatively movable rollers is capable of imparting greater deformation to a workpiece than is the system in which the workpieces pass through a throat between fixed rollers. This is so because the diminution in width in the throat between the point where the workpiece is nipped by the ro'lers, and the narrowest point of the throat, which determines the greatest possible deformation, is necessarily limited, so that the system is not of utility for other than small deformations or for burnishing of workpieces or the formation of fine grooves or threads.

The object of this invention is to provide a method which combines the advantages of both systems.

The invention provides a method of profiling workpieces that ane figures of revolution, which consists in offering a workpiece to a converging throat defined by opposed surfaces of a pair of bodies, nipping the workpiece in the throat with its axis substantially at right angles to the direction in which the throat converges, moving the bodies relatively to each other to rotate the workpiece about its axis and draw it through the throat with the axis of the workpiece moving continuously along the throat; and,

3,466,918 Patented Sept. 16., 1969 after the workpiece has been nipped in the throat, forcing the surfaces relatively towards each other to narrow the throat.

If the surfaces be provided by two rollers, one roller may have a fixed axis and the other be movable towards and away from the fixed roller; or both axes may be movable.

The utility of the method of the invention is that as great a deformation is available as with the movableroller systems, but the disadvantages of having to maintain the workpiece centrally by means of a rest or other means are eliminated.

Apparatus to carry out the method of the invention consists of two juxtaposed surfaces defining between them a convergent throat having an included angle calculated to nip a workpiece and draw it into the throat, means so to move the surfaces relatively to each other that the resultant movement is in the direction of convergence of the throat, and means to force the surfaces together to diminish the width of the throat.

If the surfaces be provided by rollers, the rollers may be juxtaposed; or one may be hollow with the second within its cavity.

The roller design may be such that the roller surfaces act on a workpiece directly; or such that the surface of one roller acts on an annular workpiece directly while the other buttresses a core or mandrel loosely contained within the cavity of the workpiece.

The invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a schematic representation of juxtaposed rollers,

FIGURE 2 is a similar view of the same arrangement with the workpiece further advanced,

FIGURE 3 is a schematic view of two rollers, one within the cavity of the other.

FIGURE 4 is a schematic view showing juxtaposed rollers with an annular workpiece,

FIGURE 5 is a schematic view of one means of forcing the rollers together,

FIGURE 6 is a horizontal section on the line 6-6 of FIGURE 5,

FIGURE 7 is a schematic side view of an arrangement in which the surfaces are rectilinear,

FIGURE 8 is a schematic view of an arrangement in which a ring is used to control the outer diameter of the finished product, and

FIGURE 9 is a fragmentary view illustrating the formation of an annular product from a blank.

In FIGURES 1 and 2, the surfaces defining the throat 10 are the peripheries 12, 14 of two juxtaposed rollers 16, 18, which are mounted for rotation about their axes. The directions of peripheral movement at the throat 10 are opposite to each other but the speed of one roller is greater than that of the other. The resultant relative movement is in the direction of the throat 10 from the side at which workpieces such as that shown at 20 are fed into the throat.

It is not necessary to particularize about the required angle of nip, differential speed and so on, necessary to nip a workpiece and draw it into the throat 10. The parameters called for are well-known in the art.

In FIGURE 1 the workpiece 20 has been offered to the throat 10 and has been nipped between the rollers. Immediately after the workpiece has been nipped the rollers are forcibly moved inwardly relatively towards each other. If the axes of the rollers remained fixed, the passage of the workpiece 20 through the throat would impose not much deformation, because the throat width does not much decrease between the point of nip and the narrowest width. However, when the rollers are moved progressively forcibly together relatively to each other, this narrows the throat 10. The workpiece continues to advance as the rollers rotate and draw it further into the narrowing throat, and the diminished width of the throat due to the natural converging of the throat and the imposed inward movement of the rollers means that the workpiece can be very much more deformed than if the rollers had not been relatively moved.

Preferably, the imposed inward movement of the rollers is stopped just before the axis of the workpiece reaches the line AA joining the axes of the rollers 16, 18, to allow time for the workpiece to be finished ofi.

In FIGURE 3, one roller 22 is hollow and the second roller 24 is mounted within its cavity. The workpiece 26 is shown advancing into the throat 28, and, when it has been nipped, the rollers are moved to bring their opposed surfaces defining the throat more closely together.

In FIGURE 4, the arrangement is akin to that of FIG- URE 1, but the workpiece 30 is an annulus, the outer surface of which is in contact with the surface of the outer roller 32. A cylindrical mandrel 34 is located within the annulus and projects from it to each side. Beyond the annulus, the mandrel is in contact with the outer surface of the roller 36. The roller 36 is circumferentially grooved at 38 to accommodate the annulus.

The annulus and mandrel are together offered to the throat 40 and are nipped. The annulus rotates as it negotiates the throat and is deformed between the outer roller and the mandrel. When the mandrel and annulus are nipped, the roller 32 is moved towards the surface of the roller 36, or vice versa, to narrow the throat 40.

In FIGURES and 6, a means is shown to move one roller towards the other to narrow the throat 42. One roller, 44, has its shaft 46 journalled in a sleeve 48, eccentrically. The sleeve is mounted for rotation about its axis by being contained in a bearing 50. An arm 51, integral with the sleeve, projects radially from it and its outer end is pivotally connected to one end of a hydraulic jack 52, the other end being fixed. When the time comes to move the rollers relatively together, the jack is actuated to extend its piston and to rotate the sleeve, whereupon the axle 46 is forcibly displaced towards the other roller to narrow the throat 42 and to impose increased deformation upon the workpiece 54. Once the workpiece has negotiated the throat, the jack is collapsed to return the roller 44 to its initial position, ready for the next workpiece.

The jack may be operated automatically upon the workpiece reaching a predetermined point in its orbit, by, for instance, triggering a switch which opens a valve 58 to feed fluid into the jack; a second switch being automatically operated by the workpiece as it leaves the throat, to open a release valve to exhaust fluid from the jack, when a spring returns the sleeve to its starting point or fluid is admitted to the jack to collapse it.

Alternatively, the jack may be manually controlled.

In FIGURE 7, a roof 62 has a sloping portion 64, extended as a level part 66. Below it, is a floor 68 that is parallel with the level part 66 of the roof. The floor is fixed longitudinally. The roof is backed by a fixed backing 70 and is guided on it, for reciprocating sliding movement under the compulsion of a power-driven pusher 72. The base is movable upwardly by a series of hydraulic jacks 74.

A workpiece 76 is offered to the convergent throat 78 defined by the sloping part 64 of the roof and the coin cident portion of the floor. As the roof moves to the left, the workpiece is nipped and is drawn into the throat 78. Immediately this happens, the jacks 74 are actuated to force the floor upwardly to narrow the throat 78. Once through the throat, the reduced workpiece is received between the parallel lands 66, 69, until the advance of the roof 68 causes its trailing edge 80 to pass beyond the workpiece, which is removed.

The apparatus of FIGURE 7 can also be used to deform annuli, by providing a slot or groove in one or other of the floor or roof, to accommodate the annulus, and by using a mandrel, and, if desired, a control ring outside the annulus to contain the distension of the ring and thus prescribe with precision the diameter or profile of the finished product.

In FIGURE 8, an arrangement like that in FIGURE 4 is shown, but a ring 84 is provided outside the annulus 86, to limit the distension of the workpiece as it passes through the throat 88 and thus precisely prescribe the outer diameter or profile of the finished product. After the throat has been traversed, the ring and the workpiece are separated.

It will be appreciated that the hydraulic jacks illustrated to move the rollers or the floor is only one of many possible ways in which the required movement can be achieved.

In order to obtain a finished product of exact required diameter using the methods outlined above, it is necessary to start ofi with an accurately prepared blank workpiece and all blanks of a series have to be almost identical in weight and dimensions. This preparation usually involves machining, which defeats the object of the process to some extent.

In an annulus the dimensions that are usually important are the outer or inner diameters. Getting the axial dimension precise is not usually troublesome because a final grinding operation to remove overflow is easily performed.

In the arrangement of FIGURE 9, the outer diameter of the annulus 90 is held to a requisite dimension by encasing the blank (dotted at 91) within a control ring 92, the inner diameter of which is exactly that which is required for the outer diameter of the workpiece, and which is of very hard material relatively to the material of the workpiece, for example cemented tungsten carbide, when the the workpieces are of mild steel.

The control ring 92, with the workpiece 90 within its cavity, is inserted between inner and outer rollers 94, 96, with a mandrel 98 between the outer surface of the inner roller 94 and the inner surface of the workpiece 90, as in the case of the FIGURE 4 arrangement; or, if the rollers be solid and juxtaposed, then as in the case of the FIGURES 1 and 2 arrangement.

In this case, as in the case of the FIGURE 8 arrangement, there is, of course, the problem of extracting the finished product from the cavity of the control ring. If the nature of the product permits, the outer diameter may have a draw taper, and lubricant can be spread between the juxtaposed surfaces to facilitate extraction. If a draw taper is not practicable, the control ring material may be so selected that the ditferential coefiicients of expansion of control ring and workpiece cause the finished workpiece to loosen in the control ring on cooling or heating, sufliciently to permit extraction. The cooling may follow the natural heating due to the deformation of the workpiece, or the workpiece may be heated before or during handling.

I claim:

1. A method of profiling workpieces that are figures of revolution which consists in offering a workpiece to a converging throat defined by opposed surfaces of a pair of bodies nipping the workpiece in the throat with its axis substantially at right angles to the direction in which the throat converges, moving the bodies relatively to each other to rotate the workpiece about its axis and draw it through the throat with the axis of the workpiece moving continuously along the throat; and, after the workpiece has been nipped in the throat, forcing the bodies relatively towards each other to narrow the throat.

2. A continuous method of profiling workpieces that are figures of revolution which consists in passing a stream of workpieces individually in succession through a throat defined by a pair of opposed rollers that are rotated about their axes at constant speeds; nipping each workpiece in the throat and drawing it through the throat by the rotary action of the rollers with the axis of the workpiece moving continuously along the throat; and intermittently forcing the rollers relatively together to narrow the throat and thereafter drawing the rollers relatively apart to their original positions; such intermittent motion being imposed on the rollers each time a workpiece is nipped in the throat.

3. A method of profiling workpieces that are figures of revolution which consists in oifering a workpiece to a convergent-divergent throat defined by a pair of opposed rollers that are rotating about their axes at constant but relatively different peripheral speeds; nipping the workpiece in the throat, with its axis substantially parallel to the axes of the rollers, for the workpiece to be drawn through the throat by the rotary action of the rollers with the axis of the workpiece moving continuously along the throat; narrowing the throat, after so nipping the workpiece, by forcing the roller axes relatively towards each other; and maintaining the throat in this narrowed condition for an interval while the workpiece advances along the throat.

4. The method of claim 3 in which the rollers are juxtaposed and their peripheries defining the throat are rotated in the same direction.

5. The method of claim 3 in which one roller is hollow and the second is contained within its cavity, in which the peripheries of the rollers defining the throat are rotated in opposite directions.

6. The method of claim 3 as applied to the profiling of annuli, including the steps of threading a cylindrical mandrel through the cavity of the annulus, and drawing the workpiece and the mandrel into and through the throat with the workpiece in contact with one roller and the mandrel in contact with the other roller.

7. The method of claim 6 including the step of surrounding the workpiece with a ring; during the passage of the workpiece through the throat expanding the workpiece into contact with the inner face of the ring; after it has traversed the throat withdrawing the workpiece from the mandrel; and separating the workpiece from the ring.

8. The method of claim 7 including the step of limiting the axial movement of the ring, as it is being deformed, in one axial direction only, to define one end of the annulus, and after separation of the workpiece from the ring, removing surplus metal at the other end of the workpiece.

9. A method of profiling cylindrical or cylindroidal workpieces which consists in offering a workpiece to a convergent throat defined by substantially rectilinear surfaces of tWo bodies that are movable relatively to each other, nipping the workpiece in the throat, with its axis substantially at right angles to the direction in which the throat extends; moving one body relatively to the other in a direction substantially parallel to one of the surfaces defining the throat, so to roll the workpiece between the bodies; and While the bodies are relatively moving in that direction, forcing them relatively together to narrow the throat.

References Cited UNITED STATES PATENTS 154,685 9/1874 Lafferty et a1. 72-91 2,061,034 11/1936 Lennon 72-9l 3,345,845 10/ 1967 Marcovitch et a1. 7291 MILTON S. MEHR, Primary Examiner US. Cl. X.R.

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