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Publication numberUS3906711 A
Publication typeGrant
Publication dateSep 23, 1975
Filing dateJun 14, 1974
Priority dateJun 14, 1974
Publication numberUS 3906711 A, US 3906711A, US-A-3906711, US3906711 A, US3906711A
InventorsNakamura Kazunori, Sibasaki Hiromu
Original AssigneeSumitomo Electric Industries
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and apparatus for applying stress relieving treatment for stranded steel wires
US 3906711 A
Abstract
A method of applying continuous stress relieving for the stranded steel wires and the likes is provided, wherein the electrical heating power source are properly combined by switching to the stress relieving devices disposed respectively upstream and downstream of a capstan of the system depending on the feeding speed of the stranded wires delivered from the stranding machine thereby applying a uniform and continuous stress relieving to those portions of the stranded steel wires that are stranded and fed during starting and stopping of the stranding machine just in the same manner as with those portions stranded and fed during the usual operation of the machine. Apparatus suitable for effecting such continuous and uniform stress relieving are also disclosed.
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United States Patent Nakamura et al.

METHOD AND APPARATUS FOR APPLYING STRESS RELIEVING TREATMENT FOR STRANDED STEEL WIRES Inventors: Kazunori Nakamura; Hiromu Sibasaki, both of ltami, Japan Assignee: Sumitomo Electric Industries, Ltd.,

Osaka, Japan Filed: June 14, 1974 Appl. No.: 479,384

US. Cl 57/34 R; 57/6; 57/156; 57/166 Int. Cl D071) 3/00 Field of Search 57/3, 6, 9, l3, 18, 55, 57/55.5, 34 R, 34 HS, 156, 166

References Cited UNITED STATES PATENTS Peterson et a1. 57/166 X Lucht et al. 57/166 X Primary Examiner-Donald E. Watkins Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A method of applying continuous stress relieving for the stranded steel wires and the likes is provided, wherein the electrical heating power source are properly combined by switching to the stress relieving devices disposed respectively upstream and downstream of a capstan of the system depending on the feeding speed of the stranded wires delivered from the stranding machine thereby applying a uniform and continuous stress relieving to those portions of the stranded steel wires that are stranded and fed during starting and stopping of the stranding machine just in the same manner as with those portions stranded and fed during the usual operation of the machine. Apparatus suitable for effecting such continuous and uniform stress relieving are also disclosed.

4 Claims, 7 Drawing Figures US Patent Sept. 23,1975 3,906,711

H G ,2 PRIOR ART METHOD AND APPARATUS FOR APPLYING STRESS RELIEVING TREATMENT FOR STRANDED STEEL WIRES BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of applying a continuous stress relieving (a kind of annealing at lower temperature than normal one) for the stranded wire consisting of plurality of steelwires and the appae ratus therefor.

2. Description of the Prior Art In manufacturing stranded steel wires by stranding plurality of wires stress relieving treatment has usually been applied just after said stranding for removing the residual stress remaining therein in order to stabilize the stranded wire products.

Typical examples of the conventional stress relieving methods and the apparatus therefor are to be described in details in conjunction with the accompanying drawings.

In one embodiment of the conventional systems shown in FIG. 1A and 1B stranded wire 2 stranded through a stranding machine 1 is taken up onto a drum 4 by way of a capstan 3 by a winding device. Then, several such drums 4 are transferred the vicinity of a heating furnace, whereby respective leading ends of the strand in respective drums 4 are rolled out, passed through the heating furnace or the stress relieving furnace 5 in parallel with each other and then taken up onto the respective drums 6 by the winding device located at the opposite side. Reference numeral 9 denotes a cooling device. This system, however, has a defeet that it requires many numbers of man-hours since the stranding process and the'stress relieving process are provided independently.

Another embodiment of the conventional stress relieving systems is illustrated in FIG. 2 proposed by Bethlehem Co. U.S.A., wherein stranded wire 2 stranded by a stranding machine 1 is passed through a capstan 3 at first and, afterwards by way of an accumulator which stores the stranded wire loops, applied with the stress relieving treatment in a heating furnace or a stress relieving furnace 5 and then taken up onto a drum 6 at a lower speed by a winding device. Reference numerals 8, 8' and 9,9 denote air cooling devices and water cooling devices disposed respectively before and after of said stress relieving furnace 5 for passing the stranded wire 2 therethrough. In this stress relieving system, complete stress relieving cannot be obtained for a. certain portion of the stranded wire when the stranding machine is stopped or operated only intermittently in the case of effecting the wire connection operationand the like. For overcoming such defect, an accumulater is used in this system for pulling back the portion not having complete stress relieving and subjecting it to the stress relieving. This system is, however, still disadvantageous in that it requires an additional device such as above mentioned accumulater thereby resulting in a complicated operation as well as having higher apparatus costs.

SUMMARY OF THE INVENTION A principal object of the present invention is to provide a method and apparatus for applying a continuous and uniform stress relieving treatment easily for the stranded wire delivered from the stranding machine that strands a plurality of steel wires throughout its operation, that is, from the starting to the arrival at a rated speed, during the operation at a rated speed and till the stopping thereby eliminating the defects of the prior arts.

Another object of the present invention is to provide amethod and apparatus for applying a uniform stress relieving for the portion of the stranded wire that is fed druing the period from the starting till the arrival at the rated speed in the same way as for those portions delivered at the rated speed during normal operation.

A further object of the present invention is to provide a method and apparatus for applying a uniform stress relieving for the portion of the stranded steel wire that is fed from the stranding machine during the period from the operation at the rated speed till stopping in the same way as for those portions delivered at the rated speed during normal operation.

A. still further object of the present invention is to provide a method and an apparatus, using the electrical heating source of the same capacity applying not only to the wire at normal continuous stress relieving velocity but also at stress relieving velocity from starting to normal velocity, even if the two stress relieving devices were disposed respectively before and after the capstan.

Further object and advantages of the method and apparatus of the present invention will become apparent from the following detailed description if read in connection with the accompanying drawings.

DESCRIPTION OF THE ACCOMPANYING DRAWING FIGS. 1A and 1B are schematic illustrations of a conventional stress relieving system;

FIG. 2 is a schematic illustration of another conventional stress relieving system;

FIG. 3 is a schematic arrangement of the stress relieving system according to the present invention; and

FIG. 4A to FIG. 4C are circuit diagrams for supplying electrical heating power to the stress relieving devices for use with the apparatus according to the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS The present invention is to be described in details by way of its illustration embodiments but and in no way is it restricted to the accompany drawings.

The embodiment in FIG. 3, showing a schematic arrangement of a continuous stress relieving apparatus for the stranded steel wire according to the present invention, comprises a stranding machine I, stranded steel wire 2 prepared by stranding, for example, a plurality of steel wires by said stranding machine, a capstan 3, a take up drum 6, heating devices 5 and 5' disposed respectively before and after said capstan 3, and cooling devices 9 and 9 disposed respectively before and after said capstan 3, all of said heating and cooling devices being used for the stress relieving. For the convenience of the explanation, 'the foregoing heating devices and cooling devices are to be referred to as heating devices or stress relieving devices 5 and 5 taken together.

When the stranding machine 1 shown in the drawing is operated normally, said machine 1 rotates at a rated speed and only the heating device 5 disposed before of the capstan 3 is operated to effect the stress relieving.

The stranded wire 2 applied with the stress relieving is wound several turns around the capstan 3 and then taken up onto the drum 6 through the heating device 5', which is not yet operated and at normal operation, disposed after the capstan 3.

According to the present invention, the uniform stress relieving treatment can be effected utilizing the continuous stress relieving apparatus described above throughout the operation of the stranding machine 1 in the manner as described below.

In the case where the normal operation of the stranding machine is interrupted temporarily, for the reason such as connection of the wires and the like, a stop button for the stranding machine is actuated, by which the electrical power source for the pre-disposed heating device is also disconnected. The strands to be stranded are, however, stranded usually up to about 3 5 m length due to the inertia force till the machine completely stops by said disconnection operation of the switch. Thus, the portion stranded by the inertia force and delivered from the stranding machine is wound around the capstan 3 as a so-called a defective portion, that is a portion not applied with stress relieving, When the stranding machine is started again, the machine begins to rotate by a DC motor or a pole number changeable AC motor, etc., and then gradually increases its speed to a predetermined lower operation speed (about one half of the rated speed for normal operation), while the strands are stranded to about the length of 5 6 m. When the speed of the stranding machine arrives at said predetermined lower operation speed, the above mentioned heating devices 5 and 5' disposed respectively before and after the capstan 3 are operated simultaneously to heat the stranded wire 2 to a predetermined temperature of 350 400 C. These heating devices 5 and 5 are, of course, designed to effect the heating at the predetermined temperature corresponding to said predetermined low speed operation. With the operation of these preand post-disposed heating devices, the stress relieving is effected in such a way that the pre-disposed heating device 5 is used for the stress relieving of the portion stranded after the predetermined low operation temperature is reached and the post-disposed heating device 5' is used for the stress relieving of the portion stranded by way of the inertia force and turned around the capstan while the stranding machine is stopped, as well as for the portion stranded in the period from the time the stranding machine is re-started till it arrives at the predetermined lower operation speed. Subsequently, when the portion stranded after the re-starting and applied with the stress relieving in the pre-disposed heating device 5 comes to the post-disposed heating device 5', the heating by the post-disposed heating device 5' is stopped, and then the electric power source for said heating device 5' is combined to the power source for the predisposed heating device 5, as shown in FIG. 4A, to increase the electrical power thereof so that the electric power supply may be increased corresponding to the accelerating characteristics of the stranding machine as the latter increases its speed to the level for the normal operation.

The circuit shown in FIG. 4A comprises a dynamotor 10 having a required capacity as the electrical power source, a predisposed heating device 5 consisting of two independent heating coils 11 and 12 and a postdisposed heating device 5 consisting of one coil 13. By switching a changeover switch 14 to the side of the coil 13, the pre-disposed heating device 5 is operated only by way of the coil 11 and the post-disposed heating device 5 is operated by way of the coil 13 without using the coil 12. The portion of the stranded wire not applied with the stress relieving and wound around the capstan 3 is applied with the stress relieving by using the coil 13 of the post-disposed heating device 5'. When the portion of the stranded wire heated by the coil 11, which forms a part of the pre-disposed heating device 5, comes to the post-disposed heating device 5, the changeover switch 14 is switched from the coil 13 to the coil 12, which forms a part of the pre-disposed heating device 5, thereby supplying electrical power simultaneously to two coils 11 and 12 of the predisposed heating device 5 to increase the electrical power of the heating device 5.

In the arrangement shown in FIG. 413, only the coil 11 is used in stead of two coils 11 and 12 shown in FIG. 4A, wherein the switch 14 for the coil 13 of the postdisposed heating device 5 is disconnected when the portion of the stranded steel wire heated in the predisposed heating device 5 comes to the post-disposed heating device 5 and, simultaneously, the outputs from the power source 10 is adjusted to a level corresponding to that for the predetermined low speed for the stranded steel wire. Thereafter, the electrical power supplied to the coil 11 is gradually increased as the feeding speed of the stranded steel wire increases from said predetermined low speed.

The arrangement shown in FIG. 4C comprises two dynamotors 15 and 16 having respectively about one half capacity of that of the electric power source 10 in the embodiment shown in FIG. 4A, one dynamotor 15 being connected to the coil 11 of a pre-disposed heating device 5 and the other dynamotor 16 being selectively connected to either of the coil 12 of the predisposed heating device 5 and coil 13 of the postdisposed heating device 5 by way of a changeover switch 14. Initially, coils l1 and 13 are operated independently from the separate power sources 15 and 16 respectively and then only of the coils 11 and 12 of said predisposed heating device 5 are operated by said two power sources.

Although some voltage fluctuations occur at the time of switching or disconnecting the switch 14, they can be reduced by the stepwise increase or decrease of the voltage. The heating devices disposed before and after of the capstan are shown herein as high frequency induction heating means, but the present invention is not necessarily limited to use such heating means and other heating means can also be used such as those utilizing Joules heat by way of direct conduction and the like.

According to the present invention, as foregoings, stress relieving devices are disposed respectively before and after of the capstan and selectively actuated by the automatic switching of the electric heating power source having a capacity required for the normal operation, and the heating outputs of the power source are automatically adjusted corresponding to the feeding speed of the stranded steel wire, whereby continuous and uniform stress relieving can be applied for those portions of the stranded steel wire that are delivered in the period of starting as well as stopping of the stranding machine just in the same way as for those portions that are delivered during normal operation at a rated speed. Thus, the present invention can produce stranded steel wire of uniform quality with convenient simple facility, thereby providing great economical advantages.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein with out departing from the spirit and scope thereof.

Whatis claimed is:

l. A method of continuous stress-relieving of a stranded steel wire simultaneously with a stranding operation, wherein said stranded steel wire is wound onto a pick-up drum by a capstan positioned intermediate a stranding machine and the pickup drum and which pulls the wire from the stranding machine and winds it onto the pick-up drum, said method comprising:

stress-relieving the stranded steel wire at stations immediately upstream and downstream of the capstan, and

adjusting the heating power of the stress-relieving means at said stations in accordance with the feeding speed of the wire from the stranding machine.

2. A method of continuous stress-relieving of a stranded steel wire simultaneously with a stranding operation, as claimed in claim 1, wherein: at the start of the stranding machine, stranding is done at a speed lower than the rated normal speed and said method further comprises: stress-relieving the wire simultaneously at said stations upstream and downstream of the capstan when a predetermined low speed is reached, so that a portion of the wire which has not been stressrelieved at all is stress-relieved at the station downstream of the capstan, and another portion which has been stranded after the stranding machine reaches the predetermined low speed is stress-relieved at the station upstream of the capstan, terminating stressrelieving at the station downstream of the capstan when said portion stress-relieved upstream of the capstan reaches the downstream stress-relief station, and increasing the speed of the stranding machine gradually to a rate of speed while gradually increasing the heating power to the stress-relieving device or devices to match the acceleration characteristics of the stranding machine.

3. An apparatus for continuous stress-relieving treatment of a stranded steel wire, said apparatus compris- 6 ing:

a capstan for leading stranded steel wire out of a stranding machine upstream thereof, and for winding the stranded steel wire onto a drum downstream thereof,

stress-relieving devices disposed respectively immediately upstream and downstream of the capstan at operative positions with respect to the steel wire, each stress-relieving device being composed of a heating device and a cooling device,

an electrical power source for supplying heating power to the heating devices of the stress-relieving devices, said heating device disposed upstream of the capstan being divided into two heating sections, and

means for selectively switching the power source from one of said divided heating sections of said heating device disposed upstream of said capstan to said heating device disposed downstream of said capstan, and vice versa.

4. An apparatus for applying a continuous stressrelieving treatment to a stranded steel wire as claimed in claim 3, further comprising: means for supplying heating power to one of the two divided heating sections of the heating device disposed upstream of the capstan and to the heating section of the heating device disposed downstream thereof when the speed of the stranding machine is at a predetermined speed lower than its rated speed, means for switching the electrical power source from the heating section of said heating device disposed downstream of the capstan to the other of the divided heating sections of said heating device disposed upstream of the capstan when the portion of the stranded steel wire given the stress-relieving treatment in said stress-relieving device disposed upstream of the capstan arrives at the heating device disposed downstream of the capstan, and means for simultaneously increasing the power supply gradually to the heating sections of the heating device disposed upstream of the capstan so as to make the heating power correspond with the accelerating characteristics of the stranding machine as its speed increases from said predetermined lower speed to said rated speed.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US359410 *Mar 15, 1887 Art of manufacturing wire ropes
US1942550 *Nov 9, 1931Jan 9, 1934Ac Spark Plug CoHeat treatment of cables
US2724944 *Dec 3, 1952Nov 29, 1955Carleton Dana BApparatus for making stranded wire structures
US3137988 *Nov 23, 1962Jun 23, 1964Vector Cable CompanyMethod and apparatus for stabilizing cables
US3217838 *Mar 4, 1963Nov 16, 1965American Chain & Cable CoEnergy absorbing device
US3283494 *Sep 24, 1965Nov 8, 1966United States Steel CorpMethod of making strands
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4063674 *Jun 25, 1976Dec 20, 1977National Musical String CompanyMethod of making a wound musical instrument string
Classifications
U.S. Classification57/314, 57/6, 57/311
International ClassificationD07B5/00, D07B5/12
Cooperative ClassificationD07B5/12
European ClassificationD07B5/12