NZ215482A - Apparatus for tensioning moving metal strip clamped between two conveyors: curved conveyor guide - Google Patents

Description

PATENTS FORM NO. 5 Complete Specification Filed: /f Class: C&) • • thornyKl ; Publication Date: ...3 0 APR J9gjr P.O. Journal, No: .(?■ NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION "APPARATUS FOR PULLING FORWARD OR HOLDING BACK MOVING METAL STRIPS" I, -WE- NORBERT UMLAUF of Haferkamp 64 D-5800 Hagen Federal Republic of Germany, citizen of Federal Republic of Germany hereby declare the invention, for which I/we-pray that a patent may be granted to me/tt&7 and the method by which it is to be performed, to be particularly described in and by the following statement ffel\owt4 by page T A.) 215482 ' - 1*- SPECIFICATION Apparatus for Pulling Forward or Holding Back Moving Metal Strips FIELD OF THE INVENTION This invention relates to an apparatus for exerting a forward or backward drag on moving metal strips or sheets. It is especially applicable to . narrow strips which are to be wound jointly side by side onto a winding shaft in order to apply separate braking drags to each strip. The apparatus includes two oppositely disposed endlessly circulating conveyor chain systems, driven by chain wheels, which clamp the strip blocki . or sheet between trolley-like clamping blocks, the trolley-like clamping, being guided on bars in a straight drag-applying zone.

DESCRIPTION OF PRIOR ART Apparatus such as this, which forms a braking stand, is disclosed in tis Patent No. 4,527,723.

. With this stand, the large pulling or restraining drag or force required to brake metal strips can be applied without harmful effects to the surface of the strip which may or may not be longitudinally divided into narrower strips. Thus, even strips having highly sensitive sui'tac^s, £ui- i] v.- v,y k J ' v - - '/ / , :/ ' • v /' ^ -.••/' ;■?' '^•~v*,S*wv'V' •»—•,^-v...-vwV,V.>3»VW" ■ '' ■ J ^ 215482 •*» D example aluminium strips, can be treated by means of this apparatus.

This is achieved mainly by feeding the chains clamping blocks together with the trolley-like / into a relatively short . clamping and drag-applying zone by means of straight guide bars, which also enable the clamping forces perpendicular to the surfaces of the strip to be resisted. In this manner, relatively large clamping forces can be accepted, which are necessary to enable . large pulling or holding-back forces to be assured without relative movement between the strip and the clamping blocks trolley-like / of the conveyor chains. By inlet and outlet divergences at the starts and ends of the straight guide bars of the clamping zone, the positive clamping .blocks . guidance of the trolley-like / is promoted. These divergences at the ends of the clamping zone avoid a sudden transition, and make possible smooth taking-over clamping block of each trolley-like/ and also ensure positive pressing of clamping blocks the trolley-like / opposite to each other in this zone. 20. with such a braking apparatus which is intended in particular for the purpose of applying high tensile or restraining forces without surface damage to metal strips, the inlet and clamping conditions are thus of determining importance.

. SUMMARY OF THE INVENTION The main object of the present invention is to broaden the scope of use of the known apparatus described above. ~1 Z26hARI987-~ij // 215482 3 Another object is to further stabilise the inlet and entraining conditions on entry of the trolley straight clamping blocks into the / strip clamping zone of the apparatus.

To this end, according to the present invention, each conveyor chain system is guided along a curved path along its whole extent except for the drag-applying zone which remains straight. With conveyor chain systems having a curved form except for the straight entraining or drag-applying zone, with which are included also the inlet and outlet inclined sections of the otherwise straight guide bars, although in essence no supporting forces occur in the curved parts of the paths of the chains, that is with chains having mainly circular arcuate paths not merely in the region of the direction reversals, the chains which are composed of a plurality of oirectly coupled together a^rwScwe very largely free of sudden directional changes. In this way the positive parallel* clamping blocks feeding of the opposed trolley-like / of the chain systems into the clamping or drag-applying zone is promotea and also a much higher speed of strip movement - for example up to l,UbO m/min. - can be reached.

The free run of the chains without abrupt directional changes can be further promoted by providing each chain system with driving chain wheels only at one end of their path, preferably the end towards which the drag is applied to the strip. Preferably then part-circular direction changing and guide elements are C 215482 - * - provided at least at the outlet ends of the chain paths remote from the driving chain wheels. These elements support the chains at the outlet end of the strip.

This arrangement applies tor generator-type drive, and W 5. is oppositely-handed for motor-type drive. Thus, at each revolution of the conveyor chain, the chain sinks only once with its slide bushings or pins which connect , clamping blocks and trolley-lifee / into the chain wheel, which is provided with semicircular recesses for engaging the chain ^ 10. pins. At the opposite ends of their paths the chains can roll without abrupt transition onto the direction-changing and guide elements. The unavoidable chain movements on disengagement and engagement of the chain wheels transmitted from the 15. chain wheels to the chains are reduced by one half and thus the life of the chains is increased.

Preferably, in each stand, across the chain paths, that is opposite to the straight, inner chain guide bars of the clamping zone, outer, circular-arc 20. shaped guide bars are provided. Th^se arcuate guide bars engage without abrupt transition into direction-changing curves which are constructed as tensioning elements or segments and are pivotally ^ journalled on a drive shaft of the chain wheels at the . inlet end of the clamping zone and at a distance from the guide segments at the outlet end of the clamping zone. With the tensioning segments or elements each disposed parallel adjacent to the chain wheels on the w drive shaft, the chain can be so guided at the inlet end \ e:' 215482 - i - ot the clamping zone that its chain axles as far as possible run beyond the engagement points of the chain with the recesses of the chain wheel. This reduces the intermittent forces upon the chain. The CD 5- engagement of the chain pins in the recesses is to be expected in particular immediately adjoining the vertical position of a semicircular recess of the chain wheel along an arc dimension of approximately 10 to 15°.

Tensioning cylinders mounted in each chain rn ^w' 10. system may act with their piston rods on the outer arcuate guide bars. In this way a lever effect centered on the chain wheel shafts can be achieved and the chains can be te.nsioned via the pivotal tensioning segments, so that the chain and drive shaft itself 15. remains free of displacements, in particular the horizontal displacements which otherwise occur.

In order to obtain space for tensioning the chains, the straight guide bars of the clamping zone preferably end at the pulling siae of the zone at a 20. aistance from the tensioning segments or elements and engage, at the opposite end, without transition into the guide segments. The direction-changing and guide - segments at the strip outlet end are thus uninfluenced ^ by adjustment movements. blocks . Because each chain and thus the trolley-like clanping/ which form the chain enter the clamping zone along a path inclined in the direction of strip feed, i.e. the space between the opposed chains is wedge-shaped at the entry, the trolley- 'can be made to come into contact —r-T"*-—•»fi»—ffir— *- ■■■»^-"i !"■ '-Ill I ■ "■ ■n-.i, --"• r- ' :15482 -fain a uniformly parallel manner, particularly taking into account the deformation of the elastic facings which are usually provided on the clamping faces of the trolley-like clanpinc blocks upon contact with the strip. The feed of the O 5. chain of the upper chain system, tor example with a slope of a fraction of 1° makes possible a specific loading which can be modified as desired exactly at that point where, due to the loadings which occur as thetoolley^-like clanping blocks come into contact with the strip, the C2 10. greatest displacement of the facing takes place. In this region the greatest specific loadings can also be brought into action.

The careful, uniform coming of the trolley-like clanping blocks into contact with the strip in the clamping zone . can be achieved also by providing the two chain systems , with a different number of divisions or trolley-like clanping block the lower chain preferably being made longer by one division or unit than the upper chain. The lower chain therefore runs around a longer circulating path, . oraer to coincide in the entraining zone with the other, upper chain and to make use in the clamping zone of the entire clamping surfaces of the trolls-like clanping blocks clanping blocks If the trolley-lxke/ are provided with lateral ^ guide rollers, the chains can be held accurately on . their specified circulating paths, since the rollers can bear and be supported against the guide bars or segments.

.The utilisation of the entire surfaces of the claiming blocks trolley-like / in the entraining or clamping zone, can be —•' achieved in a preferred manner by making the widths of 2 6 MAR 1987?!) f v ■•mi- i. ' . 1 • • • . •' - / • , / 215482 C clanping blocks the clamping surfaces of the trolley-life^ between the pivot points defined by the axes or pins of two adjacent units being equal to the spacing of the chain divisions. clanpim blocks If the trolley-like / have a variable number of support wheels, more than the minimum two wheels or rollers required may then be used if loadings such as benaing, pressure, shear and tensile stresses and torsion are to be expected, which exceed the values which can be withstood by only two wheels.

CD io. To obtain a noise-damping effect, at least the tensioning segments may be provided with an elastic coating, which moreover keeps the supporting and lateral guide rollers in better contact with the guide track.

The rollers press into the elastic coating, which may be . for example of polyurethane, and are thus kept , continually at the correct rotational speed without slipping, which furthermore contributes to the high speeds and in particular does not require any renewed accelerations. To this extent, an elastic coating of the guide track is preferred wherever small supporting forces have to be accommodated. Where high strip tensions have to be applied, especially in the clamping .-v zone, an uncoated guide track of steel is, however, preferred. In this case, in order to avoid at least . the lateral guide rollers running on steel surfaces, an elastic running insert may, for example, be inserted into a lateral groove of the guide track. It projects or extends from the track and thus keeps the rollers turning at the required speed. 1 2 6 MAR 1937& c/ * < ' 4 - " - *• ...r "/. • j i' - ■- - - / • v*: ;>&•'*-- 1 * / ® 2154*2 - fa - O For quality monitoring, in particular establishing flatness, a completely unstressed strip is absolutely essential. Since the chain systems which act on the strip immediately after treatment of the S. strip can cause the strip to be destressed to zero at its inlet to the system, a measuring section may be disposed downstream of the apparatus. This section is preferably on a stand immediately following the outlet —. end and has a conveyor chain system onto which the strip . can be laid for inspection, or which otherwise circulates continuously at the speed of strip movement.

At the strip outlet end of the apparatus, a section comprising rollers for shaping the strip into a tube may advantageously be disposed between the 15. apparatus of the invention and a pipe making machine. Use can be made here of the fact that the strip tensions, possibly as high as 200 tonnes, produce flow of the metal of the strip even in the case of thick strips. The flow or yield process can be utilised . for shaping the strip, which can be done with low energy consumption on account of the yield condition.

In order that electric current may be supplied f~~-. to the strip for galvanic processes, or the strip may be rapidly heated to a desired temperature from ambient 25. temperature in an annealing process, heat-conducting contact surfaces may be. fitted to the strip-contacting clamping blocks surfaces of the trolley-like / For example, the clanping blocks elastic facings of the trolley-like / may be replaced by copper plates, which can transmit large quantities of V .p • o 215482 ■uawsflRP' - 9 ~ h«?at to the strip in a very short time. The current clamping blocks can be applied to the trolleyv-like / as they run through the clamping zone. This means that current is supplied only during the time when large pressing forces CD 5. on the strip are present, so that electric arcs and burn stains on the surface of the strip are avoided. Apart from a better efficiency compared with conventional gas or oil-fired annealing plants, one great advantage of this measure lies in the possible switching off of the w io. heat supply at any time. By contrast, an annealing furnace must be maintained uninterruptedly at high temperature even during unavoidable operating pauses, for example at weekends.

BRIEF DESCRIPTION OF THE DRAWINGS . An example of an apparatus in accordance with the invention will now be described with reference to the accompanying drawings in which:- Figure 1 is a side view of the apparatus in the form of a stand comprising two oppositely situated 20. conveyor chain systems of which an upper chain system is shown partly sectioned and a lower chain system is shown fully sectioned; Figure 2 is a sectional view of the apparatus as seen in the direction of the arrows on the line II-II 25. of Figure 1; and Figure 3 shows the apparatus to a smaller scale incorporated in plant for making pipes f-r-om-fclat^. metal strip. ■ : ~ .i*'.' ■■ " "V'T ' - 10 215482 DESCRIPTION OF THE PREFERRED EMBODIMENT Braking and holding-back apparatus 1 comprises two chain systems 3, 4, opposed to each other in two upright frames 2, which are open at the top to facilitate installation and removal of the systems. The chain systems are installed in windows 5 of the upright frames 2, and the upper chain system 3 can be moved upwards and downwards by means of fluid pressure cylinder-operated piston rods 6 with respect to the lower chain system 4.

The chains of the systems 3, 4 are composed of a plurality of coupled together, trolley-like clanping blocks 7, which extend across the entire width of a metal strip 9, which enters the apparatus in the direction of an arrow 8 (Figure 2). The chains run on guide tracks and are supported laterally against this track by support wheels 10 and lateral guide rollers 11 at least at both sides. Each guide track comprises, in a clamping or entraining zone 12, in which the oppositely clanping blocks situated trolley-like/ 7 encompass the strip 9 on both sides and clamp it between them, straight guide bars 13 having inlet and outlet inclined surfaces 14. The track also includes tensioning segments 15 at the inlet end of the clamping zone, direction-changing and guide segments 16 at the outlet end of the clamping zone and outer, circular-arc guide bars 17, situated opposite the clamping zone. The guide tracks of the chains of the systems 3, 4 also have at least in the i I'nicw—of—t-he tensioning segments 15, an elastic coating 16 and, in addition, the surfaces of the trolley-i^Si1^ furnished with an elastic coating 2U. The clamping clanping blocks surfaces of the trolley-liks / 7 have a width in their direction of movement corresponding to the chain pitch or division T, and extend within the pivot axes defined by axles of the support wheels 10 of two adjacent trolley-like clanping blocks.

The tensioning segment 15 of each chain system 3, 4 is mounted at the strip inlet end pivotally on a chain shaft 22, alongside the chain wheels 23 which drive the chains 3, 4. The chain drive shaft 22 is journalled in a box frame 21, which is surrounded by the circulating chain system. To pivot the segments 15, which tension the chains 3, 4, the outer guide bars 17 merge without an abrupt transition into the tensioning segments 15 and are loaded by stressing fluid pressure cylinaers 24, mounted in the upper and lower box frames 21. The cylinders 24 are articulated by piston rods to beams 26 of the outer guide bars 17 and thus exert a lever action on the tensioning segments 15 when the piston rods 25 are adjusted.

The torque which is applied by a drive, which is not shown, to the chain shaft 22 is transmitted by the chain wheels 23 to the chains 3, 4, for which purpose the chain wheels 23 comprise a plurality of semicircular recesses or divisions 27, the dividing error in the location of the recesses being smaller the larger the number of recesses, whirh j-cgeiuc axles or pins 2b „r-r-i y».»i rilrjCCJiJilim ***483 clanping blocks of the trolley-like/ '• ^t the outlet end, the chains 3, 4 slide without any drive on the direction-changing and guide segments 16, which are mounted by support axles 29 on the box frames 21.

The apparatus 1 described above can, as shown in Figure 3, be incorporated in plant for forming a tube 30 from the strip 9. The high strip tension brought about by the braking apparatus 1 causes a flow of the metal of the strip and enables the strip 9 to be aeformed into a tube without high energy consumption. For this purpose, the apparatus 1 is followed downstream at the outlet end by a shaping section 31 comprising firstly a roller set 36, 37 and then, at a distance, a vertical ana a horizontal roller 32, 33, in which a first deformation of the strip 9 takes place. At a further distance downstream in the direction ot travel, there is a further roller group consisting of vertical and horizontal rollers 32, 33, encompassing the strip or tube more or less on all sides, ana this group finally shapes the strip to form the tube 3b. This is followed, for further conveyance of the tube 3D, by a known pipe drawing machine 34, which encloses the pipe between oppositely situated, circulating clamping conveyor systems. To enable possible flatness errors of the strip 9 to be eliminated before it is shaped into the tube or pipe 30, a conventional strip straightening machine 35, illustrated in Figure 3, may be disposed directly downstream of the apparatus 1 and upstream of the shaping section 31. —_____

Claims (7)

1. n TOATWECXAIM IS: 1» In apparatus for exerting a drag upon a moving metal strip, said apparatus comprising two endless conveyor chain■systems, each of said systems comprising conveyor chain means extending around an endless path, 5. at least one chain wheel for controlling the movement of said chain means around said path, said chain means, of trolley-like each of said systems including a plurality of /clanping blocfcs, .trolley-like and first guide means for guiding said /clanping blocks along a straight drag-applying zone, said 10. apparatus further comprising means mounting said systems with said zones of each of said systems adjacent each other and means for clamping said strip between said systems in said zone to allow said systems to exert said drag thereon, the improvement 15. comprising second guide means in each of said systems, said second guide means defining said endless paths to be curved along their whole extents except where said paths extend through said straight drag-applying zone ana said first and second guide means guiding said chain 20. means around said endless paths.
2. 2. Apparatus as claimed in Claim 1, in which said at least one chain wheel of each of said systems is disposed at one end of said drag-applying zone.
3. 3. Apparatus as claimed in Claim 2, wherein said 25. end of said drag-applying zone is the end towards which said drag applied to said strip is directed.
4. 4. Apparatus as claimed in Claim 3, wherein each of said conveyor chain systems further comprises at least one circular arc-shaped direction-changing guide r/-T.* r 2 6 MAR i?87%! // l V ■ i." * 1 4 . ' • . % V • / J , "■ . " ; ^ r.\y- ■ \ "' I . •. " V / ^X-4«SJ»'»M#f3Wt»-'.V>'r:----r; J — I—-. 21548 !<t segment for guiding and changing the direction of said chain means ana means mounting said at least one segment at the end ot said drag-applying zone remote from said at least chain wheel.
5. 5. 5. Apparatus as claimed in Claim 3, in which said first guide means of each of said systems comprises straight inner guide bars adjacent said drag-applying zone and said second guide means of each of said systems comprises circular arc-shaped outer guide bars, means 10. mounting said outer guide bars opposite said inner guide bars around said endless path, direction-changing curved tensioning segments for tensioning said chain means, means mounting said tensioning segments at the ends of said zone, a drive shaft supporting said at least one 15. chain wheel, said segments at one end of said zone being pivotally mounted on said drive shaft, and one end of • said outer guide bars merging without a transition into said segments at said one end and said outer guide bars terminating at the other end thereof at a distance from 20. said segments at the end of said zone remote from said at least one chain wheel. i
6. 6. Apparatus as claimed in Claim 5, further comprising fluid pressure cylinder means acting on said outer guide bars for tensioning said chain means. ' 25.
7. 7. Apparatus as claimed in Claim 5, wherein said inner guide bars terminate at one end thereof at a distance from said segments which are at the end of said zone at which said chain wheel is situated and merge at the other end thereof without transition into the O 30. segment at the end of said zone remote from said at least one chain wheel. 215132 b. Apparatus as claimed in Claim 1, wherein said first guid« means is operative to caus® said chain means clanping blocks including said trolley-lake/ to enter said drag-applying zone along a path inclined to the direction in which 5. said strip travels through said zone.

   9. Apparatus as claimed in Claim lr in which said chain means of said chain systems include a different number of txolIey*-\£fe/]Erom each other.

   10. Apparatus as claimed in Claim 1, wherein said

   10. chain means include lateral guide roller means for clarrping dIocks guiding said trolley-like/ laterally.

   11. Apparatus as claimed in Claim 1, in which said chain means includes pins pivotally connecting said clancaiig blocks trollfiy*-l4J?e/ , together to form an endless chain and said clamping blocks

   15. trolley-like/ including means defining clamping surfaces for engaging ana clamping said strip, said clamping surfaces having a width measured along the length of 1 said chain equal to the distance between the ^xes of clamping blocks adjacent pins connecting adjacent trolley-like/ to each 20. other.

   12. Apparatus as claimed in Claim 1, in which said clamping blocks„ , trolley-\Like/ include a variable plurality of support wheels ana means rotatably connecting said support ^ wheels to said/cifiSpi^bloc& for supporting said/clanpmg^ 25. blocks from said guide means.

   13. Apparatus as claimed in Claim 4, further comprising an elastic coating on said segments.

   14. Apparatus as claimed in Claim 1, in combination with a measuring section ana means mounting

   30. said measuring section downstream of said apparatus in the direction of travel of said strip. > f HA//- "1 % 215482

   15. Apparatus as claimed in Claim 14, in which said measuring section includes a chain conveyor system.

   16. Apparatus as claimed in Claim 1, in combination with a roller set for shaping said strip into a tube, means mounting said roller set downstream of said apparatus in the direction of movement of said strip, a pipe drawing machine and means mounting said pipe drawing machine downstream of said roller set in the direction of movement of said strip.

   17. Apparatus as claimed in Claim 1, in which each clanping blocks of said trolley-like/ includes means defining a surface for contacting said strip, said surface being made of electrically conducting material.

   18. An apparatus for exerting a drag upon a moving metal strip, arranged, constructed and adapted to qperate substantially as hereinbefore described with reference to any one of the embodiments shown in the accompanying drawings. BALDWIN. BOM <& CAREY ATTORNEYS/FOffl/Tl IE APPLICANTS