US3154299A

US3154299A - Method and apparatus for loosening windings of a coil prior to heat treatment

Info

Publication number: US3154299A
Application number: US121149A
Authority: US
Inventors: Kirschning Hans Joachim; Schwenke Heinrich
Original assignee: Kloeckner Werke AG
Current assignee: Kloeckner Werke AG
Priority date: 1960-07-07
Filing date: 1961-06-30
Publication date: 1964-10-27
Anticipated expiration: 1981-10-27
Also published as: GB989784A

Description

06L 1964 H. J. KIRSCHNlNG ETAL 3,154,299

METHOD AND APPARATUS FOR LOOSENING WINDINGS OF A con. PRIOR To HEAT TREATMENT Filed June 50, 1961 R S. 6 m F m ca a 0 N M 6 f. H M F %E 555 C RK 4 RT 6 M 5 Wu V MM 0 a m M mm MS \\\Y m m mm mm a l 5 w M M% pic 0 R A 5 0 6 M a a u 6 4 h \Qv 3M x W u /1? 6 v. 5 ll. I A //X/ c w. B w A y PL A 7'FORM axe/v: M070? nssewuy BY 7 w? ,W/W

ATTORNEYS United States Patent 3,154,292 METHQD AND APPAPATTE FGR L@@EP- ENG WLQDZNGd SF A C011 Ti} HEAT Hans Joachim l schning, Duisburg, and Heinrich Schwenlre, @snahrue" hausen, Germany, assignors to Kloci-znere AG, Duisburg, Germany, a corporation of Germany Filed June 30, 1961, Ser. No. 121,149 Claims priority, application Germany, .iuly 7, 1960, K 4Ll33 19 Claims. (Cl. 263-4 1l) The present invention concerns a method for the loosening of tightly wound windings of a coil to be annealed or heat treated under a heating hood, i.e., in a heat treatment furnace, as well as apparatus to carry out the method.

It is known that due to cold working of strip steel, such as takes place during cold rolling, the internal structure of the material is changed and it becomes strain hardened. Strain hardening of the material is undesirable in many instances. This hardening is, therefore, eliminated by a re-crystallizing, annealing process, in the course of which the original strength of the material is reconstituted. At the same time, by the action of protective gases, an improvement of the surface of the strip steel is achieved.

In the case of a tightly wound coil in which the windings are tightly compressed, a prolonged heating time is necessary for the heat to penetrate from the outside into the interior of the coil in order to reach the re-crystallization temperature. This drawback, namely, the prolonged time required to heat the coil, to hold it at an annealing temperature and to cool it, has been previously overcome, as is well known, by winding up, together with the steel strip, a thread on a separately installed winding machine. After completion of the winding process, the thread is pulled out and the now loose packing density of the coil permits free access of the protective gases in the furnace and allows heat to reach the individual windings of the coil. A disadvantage of this method is the requirement for a second, separate winding device on which both thread and strip steel are wound up together. The subsequent transfer of the thus loosened coil into the furnace must be accomplished in such a way that there is no dislocation of the windings with respect to the existing diameter of the coil. Technically, this is made possible by using lifting magnets, though the chance of damaging the edges of the loosened coil cannot be eliminated entirely.

The method, according to this invention, avoids this mentioned disadvantage in that a rotary movement of the coil relative to a supporting plate for the coil is provided in which the axis of movement coincides with the axis of the coil.

Specifically, each end of the coil is moved at a difierent angular velocity about the axis of the coil so that the relative angular velocity of the ends is in a direction to enlarge their diameter, thereby producing the loosening action.

The actual loosening process is performed most advantageously in the hood-type annealing furnace and, contrary to methods used so far, the process is carried out, not on a winder, but on a rotating coil supporting plate, which can be a component part of the annealing furnace. Of course, it is also possible to perform the loosening process outside of the annealing furnace.

According to a further development of the method, according to the invention, both ends of the strip of the coil are rotated relative to each other to loosen the windings by fastening the ends to suitable operating parts.

This present invention deals also with devices that carry out the above described method. According to one type of apparatus, a central spindle, around which the core ice is wound, penetrates the center of a supporting plate on which the wound coil rests, the plate in turn being provided with openings for the gas to pass through. These units are rotated, preferably in a steady and uniform rotary movement. A cylindrical casing or shell can be provided around the supporting plate and it, in turn, is rotated in an opposite direction to the spindle and the supporting plate.

For all parts of the device, i.e., for the casing, the supporting plate and the spindle, separate drives can be provided in order to enable an optimum rotary movement of these parts to most effectively accomplish the loosening process.

The present invention is explained by means of the enclosed drawing wherein FIG. 1 is a vertical cross-sectional view of an apparatus illustrating the principles of the invention and FIG. 2 is a top plan view of an apparatus incorporating the invention. As is apparent, certain conventional units are diagrammatically illustrated.

Coil 1, with spindle 2 at its center, is placed on the supporting plate 3 with the inner end of coil 1 connected to spindle 2, as indicated at B. The outer end of coil 1 is connected to the circular casing 4, as indicated at A. The process for loosening the tightly compressed windings is carried out by rotating spindle 2 and support plate 3 in one direction, as indicated by the arrows in FIG. 2, for example, and the casing 4 in the opposite direction. The turns of coil 1, moving across the surface of support 3, will move very quickly into the clearance 5 between the coil and the casing. After continued rotation, the outer turn of the coil will press against the interior surface of the outer casing 4 The drive assemblies 6, 7 and 8, which rotate the spindle 2, supporting plate 3 and easing 4 are preferably arranged in such a way that the rotational speeds of shaft 2 and of the supporting plate 3 are identical. Openings 9 extend through supporting plate 3 as shown in the drawing to permit gas to be fed to the coil from a source of treating gas diagrammatically illustrated at 10.

While We have described and illustrated an embodiment of our invention, we wish it to be understood that we do not intend to be restricted solely thereto but that we do intend to cover all modifications of our invention which would be apparent to one skilled in the art and which come within the spirit and scope of our invention.

We claim:

1. The method of heat treating a strip of metal tightly wound into a coil, comprising the steps of supporting the coil on one of its ends on a horizontal platform, causing relative rotation of the ends of said coil relative to said platform while said coil is subjected to a thermal condition.

2. A method of heat treating a tightly wound metal coil comprising the steps of vertically supporting the coil on one of its ends on a perforated horizontal surface, effecting relative horizontal movement of successive outer convolutions of the coil by rotating said coil relative to said horizontal surface and about the axis of said coil, and xposing the said successive convolutions of said coil to a heating gas passing through the perforations of said horizontal surface.

3. A method for loosening the tightly wound turns of a coil to be annealed in a heating apparatus, said method comprising the steps of vertically supporting the coil on one of its ends on a supporting plate, driving the coil in a rotary direction by an external force about its axis and relative to said coil supporting plate in a direction which opens the turns of the coil and passing a heating gas through and between the opened turns of the coil.

4. A method according to claim 3 wherein the inner and outer ends of the coil are separately driven by external forces in opposite directions.

5. A method of heat treating a strip wound into a tight coil comprising the steps of loosening the turns of said coil by separately driving the inner and outer ends of the coil about the central axis of the coil at respective relative angular velocities which reduce the number of turns and cause adjacent turns to be spaced apart, and then subjecting the coil to a thermal condition by passing a heating gas through and between the spaced turns which heats said spaced turns to a required temperature for a predetermined time.

6. In a method of heat treating a. coil which has been tightly wound, the step of loosening the tightly wound turns by separately driving the inner and outer ends, respectively, of the coil about the coil axis at angular velocities producing a relative angular velocity between said ends in a direction which reduces the number of turns in the coil, thereby loosening the turns, with open spaces therebetween, to expose the surfaces of said turns, and applying directly to the said exposed surfaces of said turns a heat treating atmosphere.

7. An apparatus for loosening the turns of a tightly wound coil and supporting said coil in a heat treating furnace after being loosened comprising a first member having means attaching to the inner end of said coil, a second member located relative to said first member to be engageable with the outer portion of a said coil attached to said first member, said members mounted to rotate relative to each other about the axis of said coil attached thereto, and means connecting to a least one of said members to rotate said first member relative to said second members, whereby the turns of said tightly wound coil are loosened by the relative movement between the inner and outer portions of the coil.

8. An apparatus for loosening the turns of a tightly 'WOIlIld coil prior to heat treatment and holding the loosened coil during heat treatment comprising a coil support plate mounted for rotation about its center, means connected to said support plate to rotate said support plate, an axially rotatable spindle mounted perpendicularly adjacent to the center of said support plate and rotatable relative to said support plate, means adapted for attaching said spindle to the inner end of a coil concentrically located around the spindle, and means connecting to said spindle to rotate said spindle, whereby the relative motion between said spindle and support plate increases the diameter of the turns of a coil mounted thereon and loosens said turns.

9. An apparatus for loosening the turns of a tightly wound coil prior to heat treatment and holding the loosened coil during heat treatment comprising a support plate mounted for rotation about its center to support the face of said coil, said support plate having transverse openings, a spindle mounted perpendicularly adjacent to said plate at said center for separate, axial rotation and having means adapted for attaching to the inner end of said coil, an unwinding member mounted for rotation around the axis of said spindle and having means adapted for attaching to the outer end of a said coil concentrically located around said spindle, and means rotating said outer member relative to said support plate and spindle, whereby the relative motion between said outer member and said support plate and spindle increases the diameter of the turns of a coil mounted thereon and loosens said turns.

10. In a heat treating furnace for heat treating a tightly Wound coil, the combination of a support plate mounted within said furnace for rotation about its center to provide a support for the face of said coil, said support plate having openings to permit furnace gases to pass through, a spindle mounted perpendicularly to and piercing said support plate at its center for separate,

axial rotation and having means adapted for attaching to the inner end of said coil, an annular casing with an inner diameter adapted to be larger than said coil mounted within said furnace for separate rotation concentric to said spindle and having means adapted for attaching to the outer end of a said coil concentrically located around said spindle, means connecting to said casing to rotate said casing in one direction, and separate means connecting to each of said spindle and said support plate to rotate said spindle and support plate in the opposite direction at a uniform rate, whereby the relative movement between said casing and said spindle and support plate increase the diameter of the turns of a coil placed within said furnace on said support plate and concentrically located around said spindle within said casing and attached thereto loosen said turns and open spaces therebetween prior to the heat treating operation, thereby exposing the surfaces of each turn to the heat and gases within the furnace.

References Cited in the file of this patent UNiTED STATES PATENTS