GB2163571A

GB2163571A - Foil tube winding machine incorporating means for controlling a cutting mechanism

Info

Publication number: GB2163571A
Application number: GB08518589A
Authority: GB
Inventors: Wilhelm Schumacher
Original assignee: Christian Majer & Co KG GmbH; Christian Majer GmbH and Co KG Maschinenfabrik
Current assignee: Christian Majer & Co KG GmbH; Christian Majer GmbH and Co KG Maschinenfabrik
Priority date: 1984-07-28
Filing date: 1985-07-23
Publication date: 1986-02-26
Also published as: GB2163571B; DE3428005C2; GB8518589D0; FR2568176A1; DE3428005A1; IT1182543B; IT8567690A0; FR2568176B1

Abstract

In order to control a cutting mechanism 17, 18, 19, 22 for dividing wound tubes 13 formed on a foil tube winding machine, computer 25, besides processing input fixed values, processes measured data of two measured value transmitters 15, 26. One transmitter 15 transmits the velocity of the fed foil web 14 and the other transmitter 26 transmits the the circumferential velocity of the wound tube 13 produced on the winding mandrel 10 of the machine. The latter transmitter 26 preferably has a sensing member butting against the inside of the formed wound tube. <IMAGE>

Description

SPECIFICATION A foil tube winding machine incorporating means for controlling a cutting mechanism This invention relates to a continuous foil tube winding machine, more especially a spiral winding machine, incorporating means for controlling a cutting member and for controlling a carriage -which carries the cutter member and which can be shifted to and fro in the advance direction of the wound tube and the speed of which during the cutting procedure is equal to the advance speed of the tube, said means comprising a computer which, besides processing input fixed values, processes impulses supplied from an electrical impulse transmitter having a measuring roller butting against a foil web fed to the winding mandrel.

A machine having the features mentioned above is disclosed in DE-PS 2724899. It has, however, transpired that, particularly in the case of thick foil webs, non-uniformities can occur during winding of the foil web on the winding mandrel. This applies generally to spiral winding machines in which the winding procedures is carried out with the aid of winding belts. These non-uniformities or irregularities are generally slight, but they have to be taken into consideration in the case of products which require a high accuracy of the length of the severed portions of tube.

The object of the invention is to provide a machine of the type mentioned at the beginning hereof in which non-uniformities occurring during the winding of the foil web onto the winding mandrel of the machine are detected and are taken into consideration in the control of a cutting member used for severing portions of tube.

In accordance with the invention, this object is achieved in a machine of the type mentioned at the beginning hereof in that a measured value transmitter detecting the rotary velocity of the wound tube in its circumferential direction is additionally provided and is coupled with the computer.

It has been shown that, as a result of the detection of the circumferential velocity of the wound tube, a correction value is obtained which allows the exactly identical length of all the portions of tube to be guaranteed. On the other hand, an apparently obvious direct measurement of the longitudinal movement of the wound tube can not yield this accuracy. This is substantiated in that errors are possible during longitudinal movement scanning. In particular, on account of the helical motion of the wound tube, a measuring wheel not exactly in alignment with the longitudinal direction of the tube leads to an erroneous measurement of the longitudinal motion of the wound tube.

Added to this as interference factors are unevennessnes on the outside of the tube or adhesive pollution on the measuring wheel. In contrast, measured value transmitters for detecting the circumferential speed of the tube transversely to its longitudinal direction can be arranged in a more angle-accurate manner.

Advantageously, the additional measured value transmitter has a sensing member which butts against the inside of the tube and which can take the form of a rotary wing mounted at the end of the winding mandrel and including at least one resilient abutment means. A sensing member acting in the interior of the formed tube is out of the reach of haphazard adjustment intervention by an operator, butts against an absolutely smooth tube surface (the smoothness being guaranteed by the directly adjacent winding mandrel), and is also free from adhesive pollution.

In the case of small tube diameters, it can, alternatively, be advantageous to provide an external measured value transmitter in the form of a Hall generator which cooperates with at least one permanent magnet revolving with the tube in the interior thereof.

Longitudinal motion fluctuations of the formed foil tube which arise at the winding mandrel during the winding operation, for instance through slippage of the winding belts of a spiral winding machine, are detected by a comparison of the values picked up at the oncoming foil web and the values of the circumferential speed of the wound tube and these are taken into consideration by the computer for appropriately adapted control of the motion of the carriage carrying the cutting member and of the instant of use of the cutting member. Thus with a machine in accordance with the invention exactly identical dimensions of the formed portions of tube are guaranteed for all foil thicknesses.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic representation of a spiral winding machine in accordance with the invention; Figure 2 is a diagram indicating the various measured values by reference to a spirallywound portion of tube; Figure 3 is a longitudinal section through a first embodiment of measured value transmitter for the circumferential motion of the wound tube along the line Ill-Ill in Fig. 4; Figure 4 is a front view of the measured value transmitter in the direction of the arrow IV in Fig. 3; Figure 5 is a schematic longitudinal section through a second embodiment of measured value transmitter for the circumferential motion of the wound tube; and Figure 6 is a cross-section through the measured value transmitter shown in Fig. 5 along the line VI-VI in Fig. 5.

Fig. 1 shows, in highly schematised form, a spiral winding machine in accordance with the invention having a winding mandrel 10 with a free end 10a on which the just-formed spirally-wound tube 13 is rotated in known manner in the direction of the arrow 12 by means of a winding belt 11. In so doing the tube 13 is rotated helically in its longitudinal direction.

To form the spirally-wound tube 13 several foil webs are generally fed to the winding mandrel 10 obliquely to the longitudinal axis of the winding mandrel 10. In Fig. 1, however, only a single foil web 14, for example a paper web, forming a basic tube is shown.

Guide rollers for the foil web(s) and a conventional gluing mechanism are not shown, for the sake of clarity.

The foil web 14 is conducted over a measuring roller 15 which, as a result of the motion of the foil web 14, experiences a rotary motion in the direction of the arrow 16.

A mechanism 17, for cutting the tube 13 to length consists of a carriage 18 which carries a disc knife 19 adjustable perpendicular to the longitudinal direction of the spirally wound winding tube 13 and which can be moved to and fro on a spindle 21 or a guideway in the direction of the double arrow 20. Drive means 22 for the carriage 18 is represented only symbolically by a small box.

The control means by which the longitudinal motion of the carriage 18 and the cutting operation of the disc knife 19 are controlled to achieve tube portions of preset length includes a first impulse transmitter 23 which is coupled with the shaft 24 of the measuring roller 15 moved by the foil web 14. This transmitter 23 supplies timing impulses to a computer 25 as a function of the rotation of the measuring roller 15. The control means also includes a second impulse transmitter 26 which supplies impulses relating to the rotary motion of the formed wound tube 13 in its circumferential direction to the computer 25. The construction of a first example of this second impulse transmitter 26 will be described in more detail hereinunder with reference to Figs. 3 and 4.

The connection of the two impulse transmitters 23 and 26 to the computer 25 is indicated in each case by a dot-dash line 27. The output-side control connection of the computer 25 to the drive means 22 for the carriage 18 and to the carriage 18 carrying the disc knife 19 itself are indicated by dot-dash lines 28.

The computer 25 is provided with a keyboard 29 by way of which constant data, such as the width B of the foil web and the inside diameter D of the wound tube 13, can be input. Fig. 2 indicates the aforesaid variables and additionally vector arrows for the web travel speed Vs detected by the measuring roller 15, for the rotationål speed Vu detected by the measured value transmitter 26 and for the resultant speed V5 of the longitudinal motion of the tube 13, which is ascertained by the computer 25 from the input data.

Figs. 3 and 4 show a first embodiment of the measured value transmitter 26 which is arranged at the end 10a of the winding mandrel 10. The hollow winding mandrel is provided at the end 10a with a front plate 30 which extends transversely to the axis of the mandrel and has a central opening into which a bearing housing 31 of the measured value transmitter 26 is inserted. An outer flange 32 of the bearing housing 31 butts against the front plate 30 and is releasably fastened to it by means of screws 33. In the bearing housing 31 there are two bearings 34 and 35 for a shaft 36. The rotor part of an electrical impulse transmitter 37 is fastened to the inner end of the shaft 36. Fastened to the opposite end of the shaft 36 is a mounting plate 38, the outer edge of which, together with an outer region of the flange 32 of the bearing housing 31, forms a kind of labyrinth seal 39.

A two-armed rotary wing 40 is releasably fastened to the plate 38 by means of screws 41. Abutment bodies 44 are mounted so as to be longitudinally displaceable in recesses 42, at both ends of the rotary wing 40. The outer ends of these abutment bodies 44 are in each case provided with cutting edges 43 and the bodies 44 are biased outwardly by respective compression springs 45. The cutting edges 43 of the abutment bodies 44 are lightly impressed into the inner wall of the tube 13 formed on the winding mandrel 10 and are pushed off helically from it so as to ensure slip-free entrainment of the rotary wing 40 without hindering the longitudinal off-take of the tube 13. A bevel 46 on each knife edge 43 ensures that, upon the longitudinal off-take of the wound tube 13, the inner wall of the tube is not torn open by the knife edges 43.

Figs. 5 and 6 show an alternative embodiment of measured value transmitter for the circumferential motion of the wound tube.

This second type of measured value transmitter consists of a Hall generator 47 which is arranged outside the wound tube 13 (indicated in Fig. 5 with dot-dash lines) and cooperates with a ring of permanent magnets 48 which revolves inside the wound tube 13 together with the tube. As shown in Fig. 6, the permanent magnets 48 are arranged at equi-distant spacings on a flange tube 49 such that they do not contact the inner wall of the wound tube 13. The flange tube 49 is anchored on the core part 50 of a carrier which is fastened on a shaft 51 and includes two pressure jaws 52 and 53. As shown in Fig. 6, the two pressure jaws 52 and 53 are mounted on guide bolts 54 anchored in the core part 50 of the carrier and stand under the bias of compression springs 55 which urge them against the inside of the wound tube 13. As a result of the frictional locking, arising in this respect, with the wound tube 13, the carrier together with the flange tube 49 is entrained by the wound tube 13. The shaft 51 is mounted so as to be freely rotatable in a bearing bush 56 of the winding head 57 of the winding machine. The contact pressure of the pressure jaws 52 and 53 caused by the compression springs 55 and the shaping of the pressure jaws 52, 53 are so selected that the wound tube 13 can be pushed in the longitudinal direction across the jaws 52 and 53 which have a braking effect.

The revolving permanent magnets 48 generate output impulses in the Hall generator which are passed as correction signals to the computer.

Claims

1. A continuous foil tube winding machine, more especially a spiral winding machine, incorporating means for controlling a cutting member and for controlling a carriage which carries the cutter member and which can be shifted to and fro in the advance direction of the wound tube and the speed of which during the cutting procedure is equal to the advance speed of the tube, said means comprising a computer which, besides processing input fixed values, processes impulses supplied from an electrical impulse transmitter having a measuring roller butting against a foil web fed to the winding mandrel, characterised in that a measured value transmitter detecting the rotary velocity of the wound tube in its circumferential direction is additionally provided and is coupled with the computer.

2. A machine as claimed in claim 1, characterised in that the additional measured value transmitter has a sensing member butting against the inside of the tube.

3. A machine as claimed in claim 2, characterised in that the sensing member is in the form of a rotary wing mounted at the end of the winding mandrel and including at least on resilient abutment means.

4. A machine as claimed in claim 3, characterised in that the rotary wing is connected by way of a shaft to an impulse transmitter arranged protected in the interior of the winding mandrel.

5. A machine as claimed in claim 3 or 4, characterised in that the rotary wing is mounted at the end of the winding mandrel by way of a bearing which is covered towards the circumference of the winding mandrel and also in the axial direction towards the rotary wing.

6. A machine as claimed in claim 1, characterised in that the additional measured value transmitter is a Hall generator which is arranged outside the wound tube and is capable of being influenced by at least one permanent magnet which is arranged inside the wound tube and revolves with the tube.

7. A machine as claimed in claim 6, characterised in that a ring of permanent magnets is provided, the magnets being arranged at a slight spacing from the inside of the wound tube on a carrier which butts resiliently against the inside of the tube.

8. A continuous foil tube winding machine substantially as hereinbefore described with reference to and as illustrated by Figs. 1 to 4, or by Figs. 1, 2, 5 and 6 of the accompanying drawings.