GB2270020A

GB2270020A - Coiler for coiling a metal strip

Info

Publication number: GB2270020A
Application number: GB9313728A
Authority: GB
Inventors: Konrad Fesl; Klaus Zeman
Original assignee: Voest Alpine Industrienlagenbau GmbH
Current assignee: Primetals Technologies Austria GmbH
Priority date: 1992-08-31
Filing date: 1993-07-02
Publication date: 1994-03-02
Anticipated expiration: 2013-07-02
Also published as: DE4321606A1; GB2270020B; ATA173492A; FR2696164A1; JPH06166452A; GB9313728D0; FR2696164B1; AT399302B; DE4321606C2

Abstract

A coiler for coiling a metal strip consists of a coiler drum (1) comprising radially adjustable segments (3, 3a, 3b), two adjacent ones of which define between them a step (13) for receiving the leading end of a strip. In order to inhibit tension fluctuations it is proposed that in the expanded position of the coiler drum (1) the segments (3) which are interposed between the two segments (3a, 3b) which define the step (13) are radially offset from the immediately preceding segments (3, 3a, 3b) by equal steps having a total height that equals the height of the step and the radial step between confronting axial edges of adjacent segments (3, 3a, 3b) is compensated in that said interposed segments (3) are inclined in the coiling sense of rotation (14) of the coiler drum (1) about an axis which is parallel to the drum. <IMAGE>

Description

2210020 COILER FOR COILING A METAL STRIP This invention relates to a

cailer for coiling a metal strip, which coiler comprises a coiler drum having radially adjustable segments, two adjacent ones of which define between them a step far receiving the leading end of a strip.

If the segments of a coiler drum in their ex- panded position constitute a circular cylinder, the leading end of the strip will initially cause a sudden increase of the peripheral velocity for the fallowina turns of the strip so that the tension will fluctuate considerably and the quality of the strip will be appreciably adversely affected. In order to ensure a gradual transition between the turns, a step -corresponding to the thickness of the strip and serving to receive the leading end of the strip Is provided between two adjacent segments so that the followinn turns of the strip can be wound step- 1ESSly Over the leading end of the strip. Because that segment which in the coiling sense of rotation directly precedes the step has a radius which gradually increases in the peripheral direction so that the strip is guided by said segment to the radius of the cylindrical envelope, the tension fluctuations are merely distributed over a larger portion of the periphery, which larger portion is determined by the transitional segment, and the undesirable influence of the tension fluctuations can merely be reduced but cannot be avoided.

For this reason it is an object of the invention to provide for coiling a metal strip a cailer which is of the kind described first hereinbefore and which is so improved that tension fluctuations can be reduced to a dearee which is insignificant for practical purposes.

The object set forth is accomplished in accOrdance with the invention in that in the expanded position of thd coiler drum the segments which are interposed between the two segments which define the step are re- dially offset from the immediately preceding segments by equal steps having a total height that equals the height of the step and the radial step between confronting axial edges of adjacent segments is compensated in that said interposed segments are inclined in the coiling sense of rotation of the cailer drum about an axis which is parallel to the drum.

The invention is based an the recognition that any tension fluctuation can be precluded only by a coiler drum which has the shape of an Archimedes' spiral having a lead that is determined by the thickness of the strip because the coiling radius increases uniformly throughout the periphery of the drum and that increase is continuously continued adjacent to the turns of the strip. But as it is hardly possible in practice to provide expanding drums having the configuration of an Archimedes' spiral, segments hdving the shape of segments of circular cylinders are provided in accordance with the invention and in approximation to an ArchimEdes' spiral are rediallV offset from each other by equal steps and in the coiling sense of rotation of the coiler drum are so inclined that the radial steps between the confronting axial edges of adjacent segments are compensated. In such a coiler the desirable coiling conditions provided by an Archimedes' spiral can ap- proximately be utilized without a need for incurring the structural expenditure involved in an exnanding coiler havinn a contour which exactly constitutes an Archimedes' spiral.

3 The segments of the expandinn drum can be radially adjusted in conventional manner by means of links or wedge transmissions. If wedge transmissions are used in which the driving wedges are provided an the drum shaft and the driven wedges are mounted an the segments, it will be Particularly simple to adant the coiler drum to different strip thicknesses. For that purpose it is sufficient to combine the driving wedges in an adjusting unit and to movably mount them an the drum shaft for an axial adjustment. The axial adjustment of the driving wedges of one of the wedge transmissions relative to the drum shaft involves a corresponding radial adjustment of the associated seament relative to the other segments so that the radial offset between the segments, which depends an the thickness of the strip, can readily be adjusted. The segments are radially adjusted in unison by an axial displacement and that radial adjustment does not affect the relative radial offset of the segments. For this reason the coiler drum which has been adjusted for a given strip thickness can be contracted and expanded as desired and this will not change the adjusted radial offset of the segments or their inclinations.

If the coiler drum is to be designated for strips having thicknesses in a larger range, the inclination of the segments must be adapted correspondingly. In that case the segments are suitably movably mounted an the driven wedges of the associated wedge transmission and it is necessary that the segments are pivoted on an axis which is narallel to the drum. This can readily be achieved, e.g., by a guide having the shape of an arc of a circle. When the inclination of the segments has been adjusted, they must be held in their inclined position during the operation of the coiler. This can be effected in a simule manner in that the swivel drives for the segments consist of axially displaceable adjusting wedges, which act in mutually opposite senses and are arranged adjacent to the mutually opposite axial edges of each segment. Acting in mu tually opposite senses, the adjusting wedges provide a self-locking support of the segments in both directions of their pivotal movement because each segment which is raised on one side will be lowered an the other side.

If the adjusting,,tiedge-g of the swivel drive are movably mounted on the driven wedges of the associated wedge transmission, the several segments can be non-rotatably supported an the driven wedges by means of the adjusting wedges of the swivel drive. For this reason a radial adjustment imparted to the driven wedges by the driven wedges cannot influence the selected inclined position of the segments. Because the adjusting wedges are axially adjustable, it is simple to actuate the swivel drive in an axial direction, particularly if axial screw drives are provided for that purpose.

A separate actuation of each of the swivel drives for the segments will not be necessary if, according to a further feature of the Invention, the adjusting wedges for each swivel drive are combined with the driving wedges of the associated wedge transmission to constitute the adjusting unit and the wedge angle of the adjusting wedges differs from that of the driving wedges. In that case an axial displacement of that adjusting unit will result not only in a radial adjustment but also in a pivotal movement of the associated segment. For a coiling of strips having thicknesses in a predetermined range that positive pivotal movement can be utilized to effect the required adaptation to a given strip thickness by a corresponding axial displacement of the adjusting unit.

An adjustment of the inclination of the sagments will necessarily result in a pivotal movement of the wedge surfaces of the adjusting wedges relative to the cooperating surfaces of the segment. To permit a compensation of that pivotal movement it is possible to provide pressuretransmitting members, which are associated with the adjusting wedges for the swivel drive and are mounted an spherical bearings and will automaticallV adept themselves to the position to which the segments bave been swivelled.

The adjusting units in which the driving wedges of the wedge transmissions are combined may be adapted to be axially adjusted by means of screw drives, by which said adjusting units are held in their adjusted axial pcsitian relative to the drum shaft. Alternatively the adjusting units of all wedge transmissions may be adjusted in unison if the relative radial offset of the several segments is ensured by a proper selection of the associ- ated wedge angle. For that purpose the adjusting units in which the driving wedges of the wedge transmissions are combined may be held to be screwably adjustable relative to a screw-thrEadEd sleeve, which is coaxial to the drum c'j' shaft and is rotatably mounted an and axially fixed to the drum shaft. A rotation of the screw-threaded sleeve relative to the drum shaft will result in an axial die-placement of the adjusting units of the wedge transmissions in dependence an the lead of the screw threads. In that case the coiler drum can be adapted in a simple manner to 311 the thickness of a given strip in dependence an the angle through which the screw-threaded sleeve is rotated, particularly if the adjusting wedges for the swivel drive are associated with the adjusting unit consisting of the driving wedges of the wedge drive.

Alternatively, different axial displacements may be imparted to the several adjusting units if the screw-threaded sleeve has screw-threaded portions which are associated with respective segments ano have different leads. In such case the wedge transmissions might have the same wedge angle.

For a rotation of the screw-threaded sleeve relative to the drum shaft and for retaining the screw- threaded shaft in a given rotational position, it is recommendable to provide a worm shaft, which is movably mounted an the drum shaft and extends tangentially to the screw-threaded sleeve and meshes with a mating annular worm wheel an the screw-threaded sleeve.

The subject matter of the invention Is illustratEd by way of example in the drawing, in which Figure 1 is a schematic axial sectional view showing a coiler in accordance with the invention, Figure 2 is a schematic transverse sectional view showing an a larger scale the coiler drum of the cailer of Figure 1.

Figure 3 is an axial sectional view showing an a larger scale a swivel drive for the segments of the cailer drum.

Figure 4 is a fragmentary axial sectional view showinn on a larqer scale a nartion of a coiler drum and Fiqure 5 is a schematic transverse sectional view showing an a larger scale the coiler drum of the illustra- tive embodiment shown in Figure 4.

In the illustrative embodiment shown in Figures 1 to 3 the coiler comprises a coiler drum 1 having a drum shaft 2 and segments 3, which are radially displaceably mounted in the flange 4 of a tubular drive shaft 5 and are adapted to be redially displaced by means of a wedge transmission 6. By means of the drum shaft 2, whbh is axially displaceable in and nonratetably connected to the hollow drive shaft 5, the driving wedges 7 of the wedne transmission 6 are axially displaced relative to the driven wedges 8, which are associated with the segments 3. Owing to the wedge face this results in a corresponding radial adjustment of the segments 3. The drive for displacing the drum shaft 2 consists of a cylinder-piston drive 9. For rotating the coiler drum 1 the tubular drive shaft 5 carries a gear 10, which meshes with a drive pinion, not shown.

Contrary to conventional cailers of this kind the driving wedges 7 of the wedge transmissions 6 are not non-displaceably connected to the drum shaft 2 but are combined in an adjusting unit 11, which is axially displaceable relative to the drum shaft 2 and consists, e.a., of a wedge bar, which can be adjusted by an axial screw drive 12. For this reason the segments 3 can be radially offset relative to each other in that the wedge transmissions 6 associated with respective segments 3 are corresnandingly adjusted by their screw dirve 12. That radial offset of the segments 3 relative to each other will be preserved if all segments are adjusted in unison by an exertion of an axial force an the drum shaft 2. As a result of that measure, the step 13 resulting between two immediatelV consecutive segments 3a and 3b can be compensated by a regular radial offset of adjacent segmEnts interposed between said two segments 3a and 3b, as is shown in a highly exaggerated manner in Figure 2. To compensate the steps which would otherwise exist between several segments - a - 3, the segments are also inclined in the coilinn sense of rotati-pn 14 of the coiler drum 1 about an axis which is parallel to the drum from a symmetrical position, which is indicated in-phantom. As a result, the segments, con- sisting of segments of a circular cylinder, from the segment 3a to the segment 3b, conform with good approximation to an Archimedes' spiral rising opposite to the sense of rotation. That conforming of the envelope of the expanded cciler drum to an Archimedes' spiral is an essential requisite for an avoiding of tension fluctuations, which would adversely affect the coiled stock.

To permit a change of the inclination of the segments in adaptation to different strip thicknesses, the is segments 3a, 3 and 3b are pivoted an axes which are parallel to the drum. According to Figure 1 the pivotal axes are constituted by pivot pins 15, which are radially displaceable in the flange 4 of the drive shaft 5 and the driven wednes 8 of the associated wedge transmission 6 constitute arc-of-a-circle guides for bearing bodies 17, which are connected to the segments. The guides 16 are coaxial to the associated pivot pin 15. The segments can be swivelled by axially displaceable swivel drives 18, which consist of mutually appositely acting adjusting wedges 19, which are provided adjacent to confronting axial edges of each segment and can be driven by respective axial screw drives 20. A pivotal movement of a seament 3 will change the inclination of the mating surface 21 of the segment 3. To compensate that change of the inclination the adjusting wedges 19 are movably mounted in an axially extending groove 22, which has the shape of an arc of a circle in cross-sEction. By an axial adjustment of the adjusting wedges 19 the segment concerned is raised an one side and lowered an the other so that the adjustina wed-ges 19 an the two sides of the segment oppose each other act-in-mutddlly-cppnstte-senses.

1 This can be effected by a relative adjustment of the adjusting wedges or by a corresponding adaptation of their inclination.

Because adjusting wedges 19 are provided an both sides of each segment, each segment is reliably supported.

In order to avoid high sliding frictions it is possible to transmit pressure between the wedge surfaces by pressure rollers 23. It will be understood that for the function of the wedges it makes no difference whether the mating sur face 21 is the wedge surface that cooperates with the rol ler 23 or that surface is constituted by the adjusting wedge 19. To preserve the pivotally adjusted position of the segments regardless of an axial displacement of the drum shaft 2, the swivel drives 18 are associated with the driven wedges 8 of the wedge transmission 7 because the position of said driven wedges relative to the associated segments will not be changed by a radial adjustment of the segments.

The design of the cailer drum shown in Figures 4 and 5 differs from the design shown in Figures 1 to 3 mainly in that the adjusting wedges 19 for the swivel drives 16 are associated with the adjusting units 11, which are provided by the driving wedges 7 of the wedge transmissions 6. Said adjusting wedges 19 have at least in a length portion a wedge angle which differs from the wedge angle of the driving wedges 7 so that an axial displacement of the adjusting unit 11 will impart to the associated segment 3 not only a radial displacement but also a pivotal movement. Because the adjusting wednes 19 provided an opposite sides of a segment must act in opposition to each other, a larger wedge angle of the adjusting wedge an one side of the segment will renuire a correspondingly smaller wedge angle of the adjusting wedne an the opposite side of the segment relative to the wedge anale of the driving wedges 7. To allow -for a sufficiently large pivotal movement of the surface 21 which is encened by the adjusting wedges, pressure-transmitting members 24 mounted in spherical bear- ings are associated with the adjusting wedges 19. To ensure that the inclination of the segments 3 cannot be adjusted before the adjusting unit 11 has been adjusted over a predetermined distance, the adjusting wedges 19 comprise a partiDn which has the same wedge angle as the driving wedges 7. In that portion, force is again transmitted by means of a roller 23 because the segments are not pivotally moved. But a space 26 for receiving the roller 23 msut be provided between the mating surface 25 of that portion and the mating surface 21 so that the rol- ls ler 23 cannot obstruct the adjustment of the inclination of the segment.

As has been stated hereinbefore, the association of the adjusting wedges 19 for the swivel drive 18 with the adjusting unit 11 eliminates the need for a separate adaptation of the inclination of the segments 3 because the axial adjustment of the adjusting units 11 will result in a radial displacement and a corresponding inclination of the segments. That fact may be utilized for a simple con- trol if the adjusting units 11 of all segments 3 can be adjusted by a common screw-threaded sleeve 27. That screwthreaded sleeve 27 is coaxially mounted on the drum shaft 2 and can be driven by a worm shaft 28, which extends tengentially to the screw-threaded sleeve 27 and is movably mounted an the drum shaft 2 and meshes with an annular worm wheel 29 of the screw-threaded sleeve 27. Because each of the adjusting units has a mating screw-threaded extension 30 meshinn with the screw threads of the screw-threaded sleeve 27 and the latter is axially fixed, a rotation of the screwthreaded sleeve will result in correspondinn axial displacements of the adjusting units. The worm shaft.26 may be driven by a motor 31 such as is indicated in Finure 5.

Claims

1. A coiler far coiling a metal strip, which coiler comprises a coiler drum having radially adjustable segments, two adjacent ones of which define between them a step for receiving the leading end of a strip, characterized in that in the expanded position of the coiler drum the segments which are interposed between the two segments which define the step are radially offset from the immediately preceding segments by equal steps having a total heiaht that equals the height of the step and the radial step between confronting axial edges of adjacent segments is compensated in that said interposed segments are inclined in the coiling sense of rotation of the coiler drum about an axis which is parallel to the drum.

2. A cailer according to claim 1 comprising a drum shaft, which is axially adjustable relative to the radially displaceable segments, and wedge transmissions asso- ciated with respective segments and having driving wedges associated with the drum shaft and driven wedges associated with the segments, characterized in that sets of said driving wedges are combined in respective adjusting units and said driving wedges are axially adjustably mounted an the drum shaft.

3. A cailer according to claim 3, characterized in that the segments are pivotally movable on the driven wedges of the associated wedpe transmissions by means of a swivel drive about an axis of rotation which is parallel to the drum.

4. A cailer according to claim 3, characterized in that consist of axially displaceable adjusting wedges, which act in mutually opposite senses and are arranged adjacent to the mutually opposite axial edges of each segment.

5. A coiler according to claim 4, characterized in that the adjusting wedges of eaCh swivel drive are movably mounted an the driven wedges of the associated wedge transmission. 5

6. A coilEr according to claim 4 or 5, characterized in that the adjusting wedges of the swivel drives are adjustable by means of axial screw drives.

7. A coilEr according to claims 2 to 4, characte- rized in that the adjusting wedges o-f each swivel drive are combined with the driving wedges of the associated wedge transmission to constitute the adjusting unit and the wedge angle of the adjusting wedges differs from that of the driving wedges.

8. A cailer according to any of claims 4 to 7, characterized in that pressure-transmitting members are associated with the adjusting wedges for the swivel drive and are mounted an spherical bearings.

9. A cailer according to any of claims 1 to 8, characterized in that the adjusting units in which the driving wedges of the wedge transmissions are combined are adapted to be adjusted by means of screw drives.

10. A cailer according to any of claims 1 to 8, characterized in that the adjusting units in which the working wednes of the wedge transmissions are combined are 311 held to be screwably adjustable relative to a screw-thresdad sleeve, which is coaxial to the drum shaft and is ratatably mounted an and axially fixed to the dru m shaft.

11. A coiler according to claim 10, characterized in that the screw-threaded sleeve is adapted to be driven by means of a worm shaft, which is movably mounted on the drum shaft.

12. A coiler for coiling a metal strip, substan- tially as described hareinbefore with reference to and as shown an the drawing.