US2704597A - rozieres - Google Patents

Description

March 22, 1955 J, A. L. ROZIERES 2,704,597

I WIRE DRAWING MACHINES Filed Nov. 12, 1947 2 Sheets-Sheet 1 March 22, 1955 J. RQZIERES V 2,794,597

WIRE DRAWING MACHINES Filed Nov. 12, 1947 2 Sheets-Sheet 2 M van 70 r Jean .A/fred Lam; fioz/cres Affarn 6y United States Patent WIRE DRAWING MACHINES Jean Alfred Louis Rozieres, Paris, France Application November 12, 1947, Serial No. 785,278

Claims priority, application France November 19, 1946 4 Claims. (Cl. 20514) It is known that in wire drawing machines the application of a counterpull behind the die considerably decreases the reaction of the die. In this case the increase in the pull ahead of the die may reach only about half the counterpull.

Thus, for a steel wire containing 0.58% carbon and having its cross-sectional area equal to 12.6 sq. mm. before drawing and 0.06 sq. mm. after drawing it has been found that:

(a) The normal drawing eifort without counterpull was 590 kg, and

(b) When a counterpull of 850 kg. was applied to the wire the effort on the front face of the die amounted only to 1060 kg., the reaction of the die having thus passed from 590 kg. to 210 kg. (1060-850).

Such decrease in the reaction of the die has made it possible to decrease the heating effect therein and, consequently, to increase considerably the speeds of wire drawing without increasing wear and tear of the dies.

In order to recover the imput of energy consequent upon the counterpull, this is utilized as drawing agent in a preceding die, while a driving motor supplies only the complement of requisite motive power, this arrangement being used for a train of consecutive wire drawing dies Fn, Fn-l, Flt-2, etc.

The existing wire drawing machines, which are based on this principle and in which the operation of wire drawing is regulated by a counterpull behind each die, have the inconvenience of causing said counterpull to be limited to a value corresponding to the lowest efficiency of wire drawing operation.

The present operation aims to provide an improved system of wire drawing in which the above inconvenience shall be eliminated and which consists substantially in causing the wire drawing operation to be regulated, instead of by said counterpull behind each die, by a pull that shall be maintained at the highest possible constant value, so that at any time the resulting counterpull shall be as strong as possible instead of being maintained at, and limited to, the value corresponding to the lowest efiiciency of the operation in the last member of the wire drawing train.

While in the wire drawing systems hitherto known the dynamometric device serving to maintain constant the counterpull Qn upstream from the die Fn is located between the traction winch of die Fn-l and the die Fn, in the improved wire drawing system of the invention the dynamometric device serving to maintain constant the pull Tn downstream from the die Fn is located between the traction winch of die Fn and the die Fn itself.

The regulation of the constant pull T for each die in the wire drawing system according to the invention may be obtained by acting either upon the winch of die Fn-l or upon the winch of die Fn, the winches themselves being controlled, through the respective dynamometric devices, either individually by any suitable driving means, such for example as electromotors, or jointly from a sole electromotor or any other suitable driving means conveniently adapted therefor.

In one form of wire drawing system according to the present invention the dynamometric device Fn acts upon the driving means of the winch Fn1 so as to maintain the constancy of the pull Tn by causing the counterpull Qn to vary, while the constancy of the pull Tn-l is maintained by the dynamometric device Fn1 acting in a similar way.

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In a further form of wire drawing system of the invention the dynamometric device Fn acts upon the driving means of the winch Fn so as to maintain constant the pull exerted thereby on the die Fn.

In the first form it is the speed of the last winch that will remain constant, while in the second form the speed of the last winch will be variable and that of the winch before last will be constant.

A still further form of wire drawing system of the invention consists in maintaining constant the pull downstream from the dies by causing the variations winches to be operated by individual speed-variators actuated by a sole motor. The speed variations of each winch are effected, as previously, by causing the variator say Vn-l to be controlled either through the dynamometric device n-l or through the dynamometric device n.

The speed variators utilized may be of any suitable kind, for example of the kind using trapezoidal belts of the Texrope type and extensible pulleys; twin conical winches with parallel shafts; hydraulic variators may be used, while winches may be of variable winding diameter, without substantially departing from the spirit of the invention.

The dynamometric devices used in the wire drawing systems of the invention may be of any suitable type, for example of the type in which the wire under treatment passes around a swinging guide-pulley carried by the free end of a pivoting arm adapted to be pivoted by a spring in the directions substantially perpendicular to the wire passing through the corresponding die, or they may be of the type in which, according to the invention, the wire under treatment passes around a guide-pulley made fast to a movable support adapted to be displaced by a spring in the directions substantially parallel with the wire passing through the corresponding die.

In order that the invention may be well understood and readily carried into efiect, the same will now be described in detail with reference to the accompanying diagrammatic drawings which show by way of example some embodiments thereof and in which:

. Fig. 1 illustrates the wire drawing machines hitherto in use;

Fig. 2 shows a wire drawing system according to the present invention, in which the dynamometric device say n is adapted to act either upon the driving means of the winch Mn-l or upon the driving means of the winch Mn;

Fig. 3 shows a wire drawing unit in which the wire drawing die forms part of the dynamometric regulator;

Cliig. 4 shows a modified form of the device of Fig. 3; an

Fig. 5 shows a wire drawing system according to the present invention, in which the various winches are driven, through the corresponding dynamometric devices, by individual speed-variators controlled from a sole driving motor.

Referring first to Fig. 1, which is illustrative of the type of hitherto known wire drawing systems, the reference numeral 1 denotes a winch which is driven by an electromotor (not shown) and exerts a pull T on the wire 2 downstream from the die 3. Before reaching the die 3 the wire 2 coming from the winch 4 and exerting a pull T on the die 5 passes first around a guide-pulley 6, the axle 8 of which is mounted on the free end of a leverarm 9 pivoting as at 10 and adapted to be acted by a dynamometric spring 11, and then around a guide-pulley 7. This portion of the wire 2 undergoes a counterpull Q to which there is added a driving complement of the winch 4 to produce a pull T between the winch 4 and the die 5. The greater the counterpull Q on the wire 2 between the winch 4 and the die 3, the stronger the spring 11 is compressed. It is therefore possible to control, for example by causing the lever-arm 9 to contact one or the other of the contact elements 1213 adapted to actuate suitable relays (not shown), the increase or the decrease of motor torque of the winch 4, as the counterpull Q varies. By suitably regulating the various parts it is possible to maintain constant the value of Q behind the die 3. The same explanations are, of course, applicable to the other sets or units of the wire drawing train under consideration. The manner in which the sets or units are operated, is diagrammatically indicated by arrows A1.

As stated hereinabove, the Wire drawing system just described has the inconvenience as follows: the stronger the the counterpull Q the lesser the reaction T- Q of the die 3, fact that calls for the highest possible Q. This, however, is limited by the breaking strength of the wire 2 leaving the last die 3. Now, for a same value of Q, the pull T upstream from the die 3 varies with the rate of elongation of the wire, state of the die, its lubrication, etc. In order to prevent T from exceeding allowable limits, and for taking into account said variations of stresses in the die, Q must be given a value corresponding to the lowest efficiency of wire drawing operation.

As already stated, this inconvenience of causing Q to be limited to said undesirable value is eliminated in the wire drawing systems designed according to the present invention and illustrated in Figs. 2 to 5, inclusive.

Referring now to Fig. 2, the wire 22 is drawn by and wound on the last winch 21 under a pull Tn that differs from the breaking strength of the Wire only in the degree of safety determined by practical considerations. The pull Tn is maintained constant during the drawing operation by causing the wire 22 to pass downstream from the die 23 around a dynamometric pulley 26 carried by the free end 28 of a lever-arm 29 pivoting at 30 and acted upon by a calibrated spring 31. A guide-pulley 27 leads the wire 22 from the die 23. The lever 29, equilibrated by the spring 31 and pull Tn on the wire 22, controls for example by means of contacts 32, 33 and appropriate relays (not shown) the variations of motor torque of the winch 24 preceding the die 23. Q (counterpull)+R (resistance of passage of the wire through the die 23)=T (pull), wherefrom it follows that Q is variable since R is variable. Said counterpull is assured by the tension of passage of the wire in the preceding die 25 less the driving complement supplied by the preceding winch 24. The relations between the dynamometric regulators and the driving means are indicated diagrammatically by arrows A2.

On the other hand, the dynamometric regulator per example of set or unit It may be adapted to act upon the driving means of the winch of said set or unit n. To this end, the relations between the dynamometric regulators and the driving means are indicated diagrammatically by arrows As replacing the corresponding arrows A2.

To prevent the wire from possibly slipping off in the course of drawing operation it is expedient to cause the same to pass from the die at a certain angle a as is illustrated in particular in Fig. 3 which, on another account, shows an improved dynamometric regulator designed according to the invention. The Winch 35 pulls the wire 36 that passes from the winch 39 around the guide-pulley 38 and through the die 37. The pulley 38 and die 37 are mounted on a support 40 displaceable in the direction substantially parallel to the axis of the die. A dynamometric spring 41 is adapted to act upon the support 40 against the pull Tn exerted by the winch 35 on the wire passing through the die 37. The support 40 carries a key 43 adapted to contact electric contacts 44, 45 that are adapted to control through appropriate relays the prime mover driving the Winch 39.

To prevent the counterpull Qn from acting upon the dynamometric device thus constituted the wire is caused to pass around the pulley 38 in a direction substantially perpendicular to the directions of displacements of the support 40. There are thus provided an improved dynamometric device and a wire drawing unit with counterpull and constant pull. In order that the wire may be bent constantly in the same sense, it will be expedient to replace the winches 35, 39 by the winches 35', 39'.

Shown in Fig. 4 is a modified form of the dynamometric device of Fig. 3, in which the support 40 carrying a die 58 is mounted on links 51, 52 pivoting at 53, 54 and pivotally connected at 55, 56 to the support 40 so that the displacements of the latter may be of small amplitude permitting the wire 50, prior to being wound on the winch 59, to pass through the die 58 without substantially changing its angle of inclination. A dynamometric spring 41 and contacts 43, 44, 45 are arranged so as to operate similarly to Fig. 3. The links 51, 52 may be disposed in any convenient way with respect to the support 40, provided that the displacements of the latter do not substantially modify the angle between the axis of die 58 and the wire 50 that passes onto and around the winch 59.

Finally, shown in Fig. 5 is a wire drawing system in which similar reference numerals indicate corresponding parts of the system of Fig. 2 and in which speed variations of the various winches, necessary for obtaining constant pulls on the wire under treatment, are obtained by means of speed-variators driven all by a single prime mover 40. Each dynamometric device, for example Dn, is adapted to control either the corresponding speedvariator Vn-l (as is diagrammatically indicated by arrow B1) intended to rotate the winch Mn-1 (24) through suitable means diagrammatically indicated by reference numeral 42, or the corresponding speed-variator Vn (as is diagrammatically indicated by arrow B2) intended to rotate the winch Mn (21) through suitable means diagrammatically indicated by the reference numeral 41.

It should be understood that the invention is not intended to be restricted to the particular apparatus described and shown, nor to the particular methods set forth, as the same may be modified without substantially departing from the spirit of the invention which is in tended to be defined in the appended claims.

What I claim is:

1. A process of counter-traction wire drawing, comprising drawing a wire through a plurality of drawing stages in series, and maintaining the traction on said wire at a substantially constant value by employing variations in the traction on the wire to effect changes in the forces acting on the wire to return said traction to the predetermined constant value.

2. A counter-traction wire drawing device comprising in combination with a drawplate and traction means, a movable holder upon which said drawplate is fixedly mounted, said movable holder being adapted to move in the direction substantially parallel to the traction on the wire, means for receiving the wire on the movable holder in a direction substantially perpendicular to the direction of the movement of the holder, said wire receiving means being fixedly mounted on the holder, whereby the traction on the drawplate is measured by movement of the drawplate holder, means for regulating the traction means on the wire to maintain the traction at a predetermined constant value, and means on said movable drawplate holder for actuating said traction regulating means.

3. A counter-traction wire drawing device comprising in combination with a drawplate and traction means, a. movable holder upon which said drawplate is fixedly mounted, said movable holder being adapted to move in the direction substantially parallel to the traction on the wire, a roller fixedly mounted upon said drawplate holder for receiving the wire in a direction substantially perpendicular to the direction of the movement of the holder, whereby the traction on the drawplate is measured by movement of the drawplate holder, means for regulating the traction means on the wire to maintain the traction at a predetermined constant value, and means on said movable drawplate holder for actuating said traction regulating means, said movable drawplate holder being supported by at least two substantially parallel rods spaced apart in the direction of movement of the holder, said rods being articulated on the holder and articulated at their opposite ends on fixed axes.

4. A counter-traction wire drawing device comprising in combination with a drawplate and traction means, a movable holder upon which said drawplate is fixedly mounted, said movable holder being adapted to move in the direction substantially parallel to the traction on the wire, a roller fixedly mounted upon said drawplate holder for receiving the wire in a direction substantially perpendicular to the direction of the movement of the holder, whereby the traction on the drawplate is measured by movement of the drawplate holder, means for regulating the traction means on the wire to maintain the traction at a predetermined constant value, and means on said movable drawplate holder for actuating said traction regulating means, said movable drawplate holder being supported by at least two rods spaced apart in the direction of movement of the holder, said rods being articulated on the holder and articulated at their opposite ends on fixed axes, and said rods being articulated on said fixed axes in such manner that the angle between the direction of movement of the holder and the direction of arrival of the wire and between the direction of movement of the holder and the direction of traction on the wire will 2,205,213 Lessmann June 18, 1940 remain substantially constant. 2,275,192 Bailey Mar. 3, 1942 References Cited in the file of this patent OTHER REFEREBLCES 5 Mueller: Notes on the Use of Bar: Pull in Wire Draw- UNITED STATES PATENTS ing, published in Wire and Wire Products, issue of 1,987,670 Drake Jan. 15, 1935 September 1935, pages 419 to 426. This publication is 2,104,656 Krejci Jan. 4, 1938 by the Quinn-Brown Publishing Co., Jersey City, N. J.

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