IL42573A - Apparatus for the production in situ of a tube of large diameter from a sheet-metal strip - Google Patents

Abstract

A machine for producing a large diameter tube from strip sheet metal material comprises a frame, a profiling station and a folding station. The frame comprises lower and upper rings which are connected to one another by vertical posts. The vertical posts carry supporting rollers, which are arranged in the form of a helix with a vertical axis. In operation strip sheet metal is fed to the profiling station where it is bent into a curve having a diameter equal to the required diameter of the tube and profiled so that subsequent turns can be slotted together. The strip is then fed to the folding station, which locks adjacent turns together. As the process procedes the tube being formed is supported by the supporting rollers by a flange formed by the folding operation. [US3863479A]

Description

nana iia ¾>S7 oaa 'ma *in rp ya Apparatus for the production in situ of a tube of large diameter from a sheet- metal strip SILO 'TOFAHRENS A.G. 0:- 009 42573/2 This invention relates to a machine for the production of a tube of large diameter, such as a silo, from a sheet metal strip coiled on a feed reel which is adapted to be erected on the ground and comprising posts disposed in an annular distribution on the ground and having supporting rollers for supporting the tube, disposed on a helix at a distance from the ground, a profiling station adapted to be erected on the ground and having a path matching the bending of the tube wall, being in offset relation to the tube and disposed after the profiling station and a further station for connecting the edges of the sheet metal strip which touch and follow a helical path. Such a machine will be referred to hereina ter as a "machine of the type specified" .

A machine of the type specified is known from U.S. Patent Specification No. 3,380,147. The posts disposed on the ground are not connected to each other which makes it difficult and cumbersome to arrange the single posts in a circle.

Furthermore, in order to avoid movement of the posts, it is necessary to anchor them well in the ground. The connection of the edges of the metal strip is achieved by welding the profiled sections of the metal strip together which only slightly increases the wall thickness of the silo at the welding line. Such a connection does not contribute much to the strengthening of the completed silo walls.

German Patent Specification No. 1,959,500 describes a machine for the production of a pipe of large diameter which, besides a profiling station, also has a folding station. The known machine can travel on top of the finished part of the silo and is thus very limited with respect to its weight and dimensions. Thus, when large silos are produced, problems relating to the necessary exactness in According to the present invention there is provided a machine of the type specified in which said posts comprise a frame of annular construction which aligns and stabilizes said posts in their position and which is adapted to be erected on the ground, the frame comprising two rings disposed vertically with respect to each other between which said posts are arranged, said further station for connecting the edges is a folding station, comprising several folding units, each having at least one pair of rollers, the path of said folding station coinciding with the helix formed by the supporting rollers, and the supporting rollers situated after the folding station serving to support the tube on its fold.

Since the machine stands on the ground together with its frame, profiling station and folding station, the steps of the method required for producing the tube from a sheet metal strip can be carried out from the —— ground irrespective of the height of the tube or silo, the tube or -Mlo helix being continued in the upward direction on the supporting rollers during the production operation, in accordance with the strip feed.

The bottom end of the finished tube resting on the supporting rollers may have a distance from the ground such that the parts of the machine resting on the ground inside the tube can be removed from the latter before it is lowered to the ground, for which purpose the tube is rotated helically in the opposite direction. The supporting rollers support the tube until it rests on the ground.

In another development of the invention, the supporting roller is mounted on a pivoting arm which is pivotable about a substantially horizontal axis and which is secured against excessive deflection towards the interior of the frame by means of a strap. The supporting rollers can adjust to small diameter variations of the tube or silo and, by their inclined position or by their distance from a reference point, indicate whether the tube is below size or oversize in the region of the frame.

If the machine has a separate infinitely controllable drive motor for and each of the profiling/folding stations, then advantageously two limit switches for. controlling one of the motors are provided on the annular frame in radially spaced relationship between the profiling station and the folding station, the inner switch being used to increase the speed and the outer switch to reduce the speed of the controlled motor* 1 ) An equalizing mechanism may be associated with the folding station to adjust the tube to the required nominal diameter if the latter is exceeded or not attained. 1 ) whenever it is a question of the motor of the profiling station and visa-versa of the motor of the folding station.

To assist the profiling and folding station drive motors, at least one of the supporting rollers may be provided with a drive comprising an infinitely controllable motor, so that there may be more than two motors to raise the silo helically. This is advantageous particularly in the production of very high and/or large-diameter silos. Silos of a diameter of more than 20 m and a height of more than 20 m may be built by means of the machine.

To prevent layers of strip dropping as a result of uneven silo drive with consequent uncoiling of the reel due to its inertia, the reel is surrounded by a boundary ring which is open on one side and which limits any increase in the feed reel diameter.

Other advantageous features of the invention will be apparent from the claims, the description and the drawing. The latter is a diagrammatic illustration of one exemplified embodiment of the subject matter of the invention showing a machine for the production of a silo.

Figure 1 is a plan view.

Figure 2 is a section through a profiling station on the line II-II in Figure 3 to a different scale.

Figure 3 is a section on the line III-III in Figufce 2 again to a different scale.

Figure is a detail of Figure 1 showing a folding station to an enlarged scale.

Figure 5 is a section on the line V-V in Figure k to a different scale.

Figure 6 is a section on the line V~ VI in Figure 1.

Figure 7 is a plan view of a supporting roller drive.

Figures 8 to 13 show variously profiled ends of a metal strip.

Figures Ik to 18 show different stages in joining adjacent edges of the strip by folding, to a different scale.

Figure 19 is a graph showing the fold width against the diameter.

The annular frame bearing the general reference 1 comprises a top ring 2 and a bottom ring 3· Each of the rings 2, 3 s formed from annular A pivoting arm 3 is mounted on each of the posts with a substantially horizontal axis GO as to pivot tov/a ds the inside of the annular frame 1. The range of pivoting movement of the pivoting arm is limited by a strap 6 which is formed with a slot to receive a stop member secured to the post . A supporting roller 7 is mounted rotatably at the free end of each pivoting arm · A co-acting roller 8 disposed on the same pivoting arm 5 ma be associated with the supporting roller 7 to prevent the fold from opening in the tube under production. A bracket 9 which projects radially inwards is disposed on one of the posts and bears two limit switches 10 and 11 in radially spaced relationship. The rollers are, in accordance with the tube to be produced, disposed helically.

A profiling station 15 is provided on the inside of the annular frame 1 near one of the supporting rollers 7 and has, in each of two planes, eight cooperating roller groups, more particularly pairs of rollers disposed with their axis at right angles to the helix under production, Figure 3 showing the top and bottom fifth pairs of rollers 18 and 1 . Instead of one substantially vertical-axis roller disposed more particularly at the top, it is possible to provide two substantially horizontal-axis rollers, so that three rollers cooperate. The rollers of the profiling station 15 are so constructed and disposed that the are side edges of a sheet-metal strip / bent as shown in Figures 8 - 13· Referring to Figure 5i superposed coaxial rollers are each disposed on identical substantially vertical shafts 22 and 23 respectively. While the shaft 22 is disposed in a fixed position between a top plate Zk and a base plate 25 > the shaft 23 can be adjusted transversely of its axis, for which purpose an adjustment mechanism is provided in the region of each bearing. The adjustment mechanism comprises a U-shaped frame 26 which is secured to the top plate 2k and the base plate 25 and between the limbs of which a bush which receives a bearing and which has a square outer periphery, is slidable horizontally. To limit the sliding movement of the bush 27 away from the shaft 22 a set-screw 28 is provided, said screw being screwed into the web of the frame 2β. The bearings at the two ends of the shaft 23 are adjustable in the same way.

As shown in Figure 3 t the top plate 2k and the base plate 25 are interconnected on the left-hand side by a supporting tube 30 , a set-screw 31 and annular segments 32 - 3^ disposed therebetween. Apertures for the passage of the set-screw 28 are provided above the annular segment 32 and in the annular segment 3½. On the right-hand side of the drawing, a supporting bar is provided, which has a screw-thread at each end, is non-adjustable, and bears at the top a supporting plate 36 provided with the top plate 2 , the bottom of said bar being screwed into the base plate 25· A motor support 37 is secured to the supporting bar 38 at a distance from the base plate 25· If two substantially horizontal-axis and possibly adjustable rollers are provided instead of one substantially vertical-axis roller, a substantially vertical shaft disposed below or above the two rollers extends only as far as the annular segment 33· A short shaft of this kind is adjustable at the annular segment 33 in the same way as the shaft 23 is in relation to the annular segments 32 and J>k.

The bottom end of each of the substantially vertical shafts is provided with an identical gearwheel, the gearwheels of associated pairs, ©f shafts, for exampl§ s afts 22 and 23» being in mesh with one another. Between two meshing pairs of gearwheels an intermediate gearwheel h> is provided in each case so that when one of the intermediate gearwheels is driven via a drive wheel kh of a transmission 5 all the gearwheels are jointly drivable by an infinitely controllable drive motor 46.

A raisable and lowerable wheel 48 is provided at each of the two large-area sides of the profiling station and is mounted for rotation in a U-shaped carriage 4 , which is adapted to be raised and lowered by means of a set-screw 50· Ώιβ carriage 49 is guided in a T-shaped recess of a guide track 1· During operation, the profiling station 1 bears on its base plate 25 and can be moved along by means of the wheels 48.

Figures 4 and 5 show the folding station. It is disposed on an inclined table 5+ n the form of annular segments, said table being inclined longitudinally in accordance with, the pitch of a helix and transversely thereto, as described hereinafter. Four folding units 55 are disposed on the table 5+, each folding unit being of identical construction except for its folding rollers 56, 57 (Fig. ). A transmission gear is disposed between a base part 58 ad two side walls 59 and 60 and comprises a substantially vertical drive shaft 6l with a drive sprocket wheel 62 and a bevel gear 63 meshing with a bevel gear disposed on a substantially horizontal shaft 65 and bearing the folding roller 56 at the end remote from said bevel gear. The folding roller 57 is disposed on a shaft 66 so as to rotate therewith, said shaft being mounted BO as to be pivotable away from the roller and being connected to the shaft 65 via a gearwheel transmission 67, the pivoted position being adjustable by means of a set-screw 68 which is borne against the side wall, the position of the folding roller 57 relatively to the folding roller 56 depending on the thickness of the fold.

The inclination of the table 5^ in the radial direction is such that in the position of the folding rollers 56 and 57 shown in Figure 5 the angle bisector is situated substantially horizontally between the axes of the shafts 65 and 66. Consequently, the folding rollers 56 and 57 abut the fold only at the adjacent sides, while there is a gap between the other parts of the rollers 5 and 57 and the tube or silo under production.

The folding station 53 is adapted to be driven by a drive motor 69, which drives the individual folding units 55 via chains, a tensioning wheel 70 being provided in each case tetween each two folding units and between a folding unit and the motor. The drive is so constructed that each chain interconnects only two sprocket wheels, so that a pair of drive sprocket v/heels 62 is arranged one above the other at the folding units 5 adjacent the drive motor 6 .

The folded joints shown in Figures Ik - l8 are produced at the folding station 53.

A helically extending table 73 is disposed at the table 5^ by means of yokes 72 and bears a plurality of (six in this case) radially slidable co-acting rollers 7^ of an equalizing mechanism. Each of the co-acting rollers is mounted in a bearing 75, the outer square periphery of which is slidable in a yoke % engaging around it in the form of a U on the table 73, a set-screw 77 being screwed into the web of the yoke and being adjustable against the bearing.

A co-acting roller 7*a is disposed above each of the co-acting rollers 7^ and its bearing is constructed in the same way and is transversely slidable in the same way as the bearing 75 of the co-acting roller 7^, although the yoke 78 in this case engages around the bearing of the co-acting roller ? at least at its underside. The yokes 78 are secured to a retaining plate 79 disposed thereabove and borne relatively to the table 73 by supports 80.

The co-acting rollers 7k are adjustable against the bottom part of a screwthread and the co-acting rollers 7^a are adjustable against that part of the screwthread of the tube which is situated thereabove and which is separated by the fold. By means of each separately adjustabl co-acting roller, the sheet-metal strip can be pressed into the folding rollers and it is possible to vary the tube diameter within given limits.

Only a few operations are required to dismantle the machine into readily transportable parts, the annular frame 1 being dismantled while the profiling station 15 and the folding station 53 are removed from the annular frame, the yokes 72 being removable from the table 5^· A reel 83 is disposed next to the profiling station 15 and serves to receive a reel of strip. A guide mechanism is provided to guide the strip before entry to the profiling station 15 at the side wall thereof adjacent the reel 83, said side wall having a substantially vertical slot, the guide mechanism comprising a guide plate which at this side is vertically adjustable and, in particular, is formed with a slot and a top guide member and a bottom guide member 8 for the strip are disposed preferably adjustably at said guide plate. The correct width of the fold required to be produced in the profiling station can be adjusted by means of the guide members. The latter project about 30 cm beyond the guide plate and extend approximately as far as the first roller, while the bottom guide member 8k can project further as illustrated.

By means of the guide members the strip can be pressed downwardly or upwardly as it enters the profiling station 15· The guide members may be straight or curved and be disposed at an angle. The stationary part of the reel 83 has a boundary ring 85 which is open in the direction of the annular frame 1 and which surrounds the reel of strip in spaced relationship and prevents excessive increase in the diameter of the reel if the speed of the rotary movement thereof is reduced.

Figure 7 illustrates a drivable supporting roller 7a. mounted on a shaft 87 and being adapted to be driven via a V-belt (not shown) by means of an infinitely speed-variable drive motor 88. The shaft 87 is mounted in a frame 89 disposed on one side of one of the posts , on the other side of which the drive motor 88 is disposed on a base plate 0 connected to the frame 89. The frame 89 and the base plate 90 may be connected to the associated post either rigidly or by means of a pivoting arm 5· A gearwheel mounted on the shaft 87 may be used to drive a co-acting roller 8 mounted in the frame 89.

In order to produce a silo, the machine is assembled in the arrangement shown in Figure 1 at the erection site which has been prepared by means of a concrete slab or the like, the distance between the two rings 2 and 3 of the annular frame 1 preferably being greater than twice the pitch of the helix of the tube under production, the strip path determined by the roller path in the profiling station extending a slight distance from the helix determined by the supporting rollers 7. he top ring of the annular frame 1 may also extend helically, while the superposed ends may be interconnected by a vertical connecting portion. The top supporting roller 7 is preferably at a level equivalent at least to twice the pitch of the tube under construction.

The strip path within the profiling station 15 is so devised that the edges of the strip are bent as shown in Figures 8 to 13 while the part of the strip situated therebetween is at the same time bent according to the diameter of the tube under production.

Coming from the reel 83» the strip is fed to the profiling station 15 and then, as shown in Figure 6, is borne by its top bent edge b -the supporting rollers 7i the top rim thereof bearing in contact always in the region of the bend situated at the vertical wall of the tube. The strip is taken by its bottom end between the limit switches 10 and 11 , the outer limit switch 10 reducing the speed of the drive motor ½ of the profiling station 15 while the limit switch 11 reduces its speed so that it is controlled according to the speed of the drive motor 69 of the folding station 3· After.the limit switches 10, 11, the strip which has been bent at both edges is passed through the folding station, where the adjacent edges of the strip- are interconnected by folding as shown in Figures 15 - l8, after prior engagement as shown in Figure 14, as soon as two turns are disposed one above the other.

The tube or silo is produced continuously as described above, the tube being slowly formed into a helix in the upward direction according to the required height. As soon as this has been reached, the tube is cut off level at the bottom. The profiling station 15 and the reel 83 are removed from the interior of the annular frame 1 , and the same applies to the inner parts of the folding station 53 and the equalizing mechanism 7^ , 7^a, and the bracket 9 with the limit switches 10 and 11. The tube is then lowered by rotation in the opposite direction until it rests on the ground.

Figure 19 is a graph showing favourable fold widths F in mm against the diameter D in m of the tube and against the thickness of the strip, the curve a applying to a strip thickness of 1-2.5 mni i and curve b_ applying to a strip thickness of 2-5 nun, and curve c_ a strip thickness of -8 mm. Tolerances of +.50$ from the indicated values are possible. 42573/3

Claims (1)

1. 2. A machine according to Claim 1, in which the frame comprises a bottom ring which is adapted to be erected on the ground, and a top ring which is disposed thereabove and which is connected to the bottom ring by vertical posts, the distance between the top and bottom rings being greater than twice the pitch of the helix defined by the supporting rollers. 42573/2 3. A machine according to claim 1 or 2, in fhich each supporting roller is mounted on a pivoting arm which is pivctable about a substantially horizontal axis and which is secured against excessive deflection towards the interior of the frame by means of a strap. 4. A machine according to claim 3 , in which each pivoting arm is pivotally mounted on a vertical post. 5. A machine according to any preceding claim comprising a pair of rollers formed as a roller and a counter roller and having parallel axes, characterized in that the axes of the rollers are situated horizontally and the counter roller is situated on top of the fold. 6. A machine according to any of the preceding claims, in which a separate steplessly variable driv motor is provided for each of the profiling Btation and the folding station, and two limit switches for controlling one of the motors are provided on the annular frame in radially spaced relationship between the profiling station and the folding station, the inner switch being used to increase the rotary speed and the outer switch to reduce the rotary speed of the controller motor, whenever it is a question of the motor of the profiling station and vice-versa of the motor of the folding station. 7. A machine according to any of the preceding claims, in which an equalizing mechanism is provided for the folding station. 4.2573/2 8. A machine according to any of the preceding claims, in which the frame comprises a plurality of detachable parts. 9. A machine according to any preceding claim, in which the axes of rollers of each folding unit are disposed, in operation of the machine, at an angle to the wall of the tube under production such that those parts of the rollers which are remote from the fold are at a distance from the tube wall. 10. A machine according to any preceding claim, in which at least one supporting roller is provided with a drive comprising a steplessly variable drive motor. 11. A machine according to claim 10, in which a slipping coupling is provided between the supporting roller and the variable drive motor. 12. A machine according to claim 11, in which the slipping coupling is a Tf-belt. 13· A machine according to any precedin claim, in which a reel winch is provided for unwinding the feed reel and comprises a boundary ring which is open on one side and which surrounds the feed reel. Fo the Applicants HE/md