EP0068835B1

EP0068835B1 - Winding strip material

Info

Publication number: EP0068835B1
Application number: EP19820303314
Authority: EP
Inventors: Alan John Bootan
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-06-27
Filing date: 1982-06-25
Publication date: 1986-03-26
Also published as: EP0068835A1; DE3270083D1

Description

This invention relates to a method of and apparatus for controlling the winding of strip material from a supply thereof onto an arbour, drum, former, reel or the like.
During the winding of strip material onto a drum or the like in order to achieve a wind of the desired tightness and quantity it is necessary to control the tension that is being exerted upon the material whilst it is being wound during the winding operation. In particular, it is usually desirable that after winding the turns of the wound material should not be able to move easily relative to each other.
With a view to controlling the effectiveness of a winding operation, i.e., the transfer of strip material to be wound from a supply thereof through a working region and back to a rewind station it has been proposed in European Patent Specification No. 0 006 179 to provide a catenary like loop at a predetermined location in the strip material feed path from the supply to the pick up or rewind station, the loop being located in a suction box or container whereby controllng the suction effect the overall length of the loop can be controlled within predetermined limits. By this control of the loop length it is possible to control the overall tension and feed conditions for the strip material during its travel through the apparatus. The above mentioned specification also discloses monitoring the position of the lowermost level of the slack length and controlling material travel conditions such that the lowermost level of the slack length loop is kept between the two levels located one above the other.
In practice, it has been found that the use of the suction arrangements for controlling the amount of material in the slack length loop does not avoid the problem of the material becoming damaged when handling relatively distortable material such as plastics strip, of for example relatively small cross section immediately after the extrusion thereof from an extruder.
It is a particular object of the present invention to be able to wind plastics material as it is being extruded from an extruder.
According to a first aspect of the invention there is provided a method of controlling the winding of strip material onto an arbour, drum, former, reel or the like by guiding the strip material by way of spaced apart guide means so located with respect to each other as to allow a length of the strip material to droop catenary like between the guide means to provide a slack length in the strip material, and by controlling the material travel between the guide means so that the lowermost level of the slack length is maintained between two levels one above the other, characterised in that the strip material whilst in the slack length is guided by an edge or edge region thereof cooperating with a further guide means presenting a working surface which is inclined to the vertical.
According to a second aspect of the invention there is provided apparatus for controlling the winding of strip material from a supply thereof onto an arbour, drum, former, reel or the like, including spaced apart guide means so located in the feed path of the material from a supply thereof to a drum or the like, as to permit a length of the material to droop catenary like between the spaced apart guide means to provide a slack length in the strip material, means for controlling the rate of travel of the strip material through the slack length so that the lowermost level of the slack length is maintained between two levels one above the other, characterised in that further guide means are provided for presenting an inclined guide surface or the like to an adjacent edge or edge region of the strip material whilst it is in the slack length.
Preferably, the slack length guide means comprises a plate or other surface which is inclined to the vertical in a fixed or selectively adjustable manner.
For a better understanding of the invention and to show how to carry the same into effect reference will now be made to the accompanying drawings in which:-

Figure 1 is a schematic side view representation of a strip material winding installation including a strip material winding machine and a buffer unit interposed between the machine and a supply of strip material (not shown);
Figure 2 is a plan view of the installation of Figure 1;
Figure 3 is a sectional view of the buffer unit of Figures 1 and 2;
Figure 4 is a schematic perspective view of the winding machine of Figures 1 and 2;
Figure 5 is a block diagram of an electrical control circuit for inter-relating the operation of the winding machine and the passage of strip material through the buffer unit; and
Figure 6 is an exploded view of a mandrel arrangement affording adjustable mounting for a drum or the like for receiving the wound strip material.

Description of the Preferred Embodiments

Referring now to the drawings and more particularly to Figures 1, 2 and 3 which show a winding machine 1, and a buffer unit 2 which is positioned in the feed path between a supply of the strip material 3, the supply not being shown, and the winding machine 1.
For convenience of description the details of the construction of the buffer unit 2 will be considered initially, after which the details of the winding machine will be considered. Following this the inter-relation of the machine 1 and the buffer unit 2 will be described in order to achieve the desired winding of the strip material 3. As shown in the Figures 1 to 3 the buffer unit 2 includes a framework including a base 4 and support means or uprights 5, 6 which are secured or supported by a back plate 7. As will be particularly seen, in particular Figure 3, the upright 5, 6 are so mounted from the base 4 that the plate 7 is inclined to the vertical. The inclination is at a required angle. For example, the inclination can range between 1° to 30° with a particular range being between 5° to 15°.
It will be appreciated that if it is desired arrangements may be made to allow for adjustability of the inclination of the back plate 7. For convenience, Figure 3 shows an arrangement for enabling the adjustment of the inclination. As shown the arrangement includes pivoting the uprights 5, 6 to the frame 4 by pivots schematically shown. A link or the like 8 is pivoted at one end thereof 9 to the base 4, there being one such link for each support 5, 6. A lengthwise slot 10 is formed in each link and the links are secured to the uprights each by means of a retaining bolt or screw 11 engaging the slot and the uprights. If desired, the adjustability can be achieved by arranging for the back plate to be pivotally mounted and the links or the like co-operating with the pivoted plate 7.
If desired, the buffer unit may be formed into a chamber 2A by mounting a front plate 12 or wall to the uprights 5, 6. Conveniently, the front wall 12 would be transparent. Also, if desired, the back plate may be transparent so that the situation relating to the material passing through the chamber 2A may be readily noted.
Preferably, means (not shown) are provided for enabling selective adjustment of the spacing between the back plate 7 and the front plate 12 so that the chamber 2A can accommodate varying widths of the strip material. Conveniently, the spacing adjustment means can comprise spacers or the like which are engageable with bolts provided for mounting the back plate 7 and the front plate 12 to the uprights 5, 6.
A strip material feed roller 13 is provided upon a support 14 located near the end wall or upright 5 and a second material feed roller 15 is provided on a support 16 located near the end wall or upright 6. In addition, a sensing means 17 is provided in the vicinity of the feed roller 15 for measuring the length of strip material which has been fed past the roller 15.
The axes of rotation of the rollers 13, 15 are perpendicular to the plane of the back plate 7. Thus if the plate is positionally fixed to the uprights the rollers can conveniently be mounted from the uprights. If the plate is pivotally mounted the rollers can be mounted from the plate 7.
As can be seen from Figures 1 and 2 the width of the chamber 2A is relatively narrow as compared with its length and depth. In practice, the internal width of the chamber 2A needs only to be slightly greater than that of the strip material 3 being fed so that whilst a strip of material being fed can easily pass from the feed roller 13 to the output roller 15 with a length 3A providing the 'slack length' by drooping into the chamber 2A catenary fashion. The width of the chamber is selected such that the width is not sufficient for the'slack length' easily to tangle or otherwise jam in the chamber 2A.
Because of the inclination of the back plate 7, and as the feed rollers 13 and 15 have their axes of rotation perpendicular to the plane of the back plate 7 whatever the inclination angle of the latter to the vertical direction a bias is introduced, during the feed of the material, into the 'slack length' so that it tends to fall, i.e., lie, towards and thus abut the inside surface 18 of the plate 7. The contact is along the edge or edge region 19 of the strip length 3A. That is to say during the travel of the strip material 3 through the chamber 2A the portion 3A thereof at any time forming the 'slack length' runs against the surface 18 of the plate 7. Thus the surface 18 defines for the adjacent edge 19 of the strip 3 a guide surface or reference plane during its movement through the chamber.
Extensive investigations have shown that the fact that the edge 19 runs against the surface 18 does not lead to any adverse increase in the winding tensions that may be produced in the strip material during winding. In fact it is believed, as a result of winding very easily stretchable materials, that the use of the apparatus of the invention does not introduce any tension other than that necessary to obtain a correct lay on a drum. In the circumstances it has been found that the winding process does not damage the material whether it is symmetrically or unsymmetrically profiled material that is being wound. In addition, it has been established that the running contact between the edge 19 and the surface 18 has greatly reduced the possibility of tangling or jamming of the strip 3 whilst in the chamber 2A even when winding relatively warm plastics strip which is very highly susceptible to stretching and twisting during handling in the warm condition. These warm winding conditions are a very common factor involved in the winding of plastics material as it is produced at the output of a plastics extrusion machine. It is believed that the provision of the guide surface inclined to the vertical provides a steadying influence on the orientation of the material in the chamber throughout its complete passage through the chamber thereby offsetting the induction of twist which usually leads to tangling of the strip.
A photoelectric detection system 20 is provided for determining the position of the 'slack length' with respect to predetermined upper and lower levels 21 and 22 relative to the depth of the chamber 2A. The detection system 20 includes at the upper level a photoelectric detector 23 and an associated emitter 24 suitably aligned therewith. The system also includes at the lower level a detector 25 and an associated suitably aligned emitter 26.
Each photoelectric detector unit 23, 25 is arranged to produce a control signal which is applied to a control unit (not shown in Figures 1 and 2) associated with the winding machine 1.
In practice, the difference in the rate of strip material feed into the buffer unit chamber 2A and the delivery therefrom is such that the 'slack length' 3A interrupts the light path between the emitter 24 and the detector 23 at the upper level 21 and such that it does not interrupt the light path between the corresponding units 25 and 26 at the lower level 22. That is to say the detector 23 at the upper level can be regarded as being normally OFF and the detector 25 at the lower level 22 can be regarded as being normally ON.
In use, if the difference between the feed of the strip 3 to the chamber 2A and the delivery therefrom is such that more than the predetermined amount remains in the chamber during the winding operation the amount of 'slack length' 3A increases and when its length is such that it has effectively lowered sufficiently to pass through the above defined lower level 22 the light path between the detector 25 and the emitter will be broken whereby the detector 25 will be effectively switched off thereby changing the electric signal delivered to the control unit.
In practice, this signal change is a cut-off signal which is arranged to speed up the rate of the winding of the material onto a drum or the like, or if it is more convenient to slow down the rate of discharge of the material from the supply, i.e., the delivery rate to the chamber 2A.
If on the other hand the feed of the material from the chamber 2A starts to exceed the rate at which it is delivered to the chamber 2A it will be clear that the length of the strip material forming the 'slack length' will be reduced and, in consequence, the lowermost part of the'slack length' catenary will move upwards within the chamber 2A and if the imbalance of the strip material continues a point will be reached in which the lowermost level of the 'slack length' will move above the upper level 21. At this point of time the 'slack length' 3A will cease to interrupt the light path between the emitter 24 and the detector 23 whereby the detector 23 is effectively switched ON and will thus produce an output signal which is applied to the above mentioned control unit. As has been mentioned the output signal can be utilised either to reduce the rate of winding onto a drum or to increase the rate of material supply to the chamber, according to whichever adjustment is considered to be the most convenient.
A winding unit for receiving the strip material after it has passed through the chamber 2A will now be briefly considered in relation to Figure 4. It should be noted that the winding unit of the Figure is schematically represented and that, in practice, the relative positioning of the components may differ from that shown in the Figure 4. Thus the Figure 4 may be regarded as illustrating the principal features of a winding machine. The winding machine includes an upper shaft 27 adapted for mounting a bobbin, drum, former, spool, reel or the like 27A (not shown in Figure 4) onto which the strip material 3 is to be wound, and a lower shaft 28 adapted to mount a bobbin, drum, former, spool reel or the like and located effectively beneath the shaft 27. The shaft 27 extends outwardly from the side of a housing unit 29 which is mounted upon a support frame or pedestal 30.
The shaft 28 is carried from bearing arrangements 31. Similarly, the shaft 27 is mounted from suitable bearing assemblies 32 provided with the housing unit 29.
The shafts 27 and 28 are connected to receive drive from the output shaft 33 of an electric motor 34 by way of a belt drive system 35. This drive system includes a layshaft unit 36 mounted from bearings 37. The layshaft unit 36 is provided with a pulley wheel 38 which mounts a drive belt 39 connecting with a pulley wheel 40 on the shaft 27.
The layshaft unit is provided with a pulley wheel 41A which mounts a drive belt connecting with a pulley wheel 43 on the lower shaft 28.
A clutch arrangement 41, 42 is provided on the layshaft unit 36 whereby drive from the shaft unit may be selectively fed from the drive motor to the upper or the lower shafts 27, 28.
In practice, the clutch arrangement 41 provides a tube 37A journalled on the shaft unit 36, which carries the pulley 41A and which can be selectively coupled to receive drive from the shaft 36 or to allow the shaft 36 to run freely within the tube. As shown the drive system 35 includes a pulley 35A on the shaft 36 and a belt 35B receiving drive from the motor output shaft 33.
The clutch arrangement 42 is of a generally similar construction.
It will be observed in connection with the use of the concentric tube arrangements in the clutch constructions that the shaft 36 effectively provides an extended length bearing support for the adjacent ends of the tubes 36A, 37A.
It will be understood that other forms of clutch could be used.
Upper and lower strip material feed and guide rollers 43A and 43B are provided for guiding the strip material during the winding operation in such manner that the material is laid onto the drum or the like in regularly spaced side by side arrangement and in layers. These rollers 43A and 43B are mounted from a traversing mechanism 44 which is supported from the housing unit 29. The mechanism includes a traversing block having arms 46A and 46B which respectively mount the rollers 43A and 43B. The block 45 is moveable lengthwise of a traversing shaft 47 connected to receive drive from the motor 34 by way of a belt drive including pulley wheels 49 and 50, and belt 48. The traversing mechanism 44 incorporates means (not shown) whereby the movement of the block 45 changes, that is reverses, direction each time it completes a traversing movement of a desired amount.
The electromagnetic clutches 41, 42 enable disengagement of the drive for various operational purposes such as, for example, when a drum or the like is being changed after the desired amount of strip material has been wound onto the drum and is being replaced by an empty drum.
In addition, the provision of the clutches 41, 42 allows the changeover of the winding operation from drum to drum i.e., from a drum on one shaft to a drum on the other shaft without it being necessary to stop the winding operation. In situations where the rate of material feed is high the fast changeover between drums is very important so as to avoid excessive waste of material.
In order to facilitate the changeover of the drums to and from the shafts 27 and 28 each shaft 27, 28 is provided with a spring loaded mandrel 60 which essentially includes four radially directed blocks 61, 62, 63 and 64 equiangularly spaced around the associated shaft 27 or 28. The blocks are held in place by countersunk bolts 65 and are resiliently loaded by compression springs 66A.
If it is desired to expand the overall diameter of the mandrel a second set of the blocks i.e., blocks 61A, 62A, 63A and 64A, can be mounted to the blocks 61-64 by using longer bolts 65.
It will be understood that the buffer unit 2 and the winding machine 1 need to be electrically interconnected. In the drawings this connection is very schematically shown by the cable and fittings 66.
When the apparatus is in use the strip material is engaged with the rollers 13 and 15 and also by way of the roller 43A or 43B of the traversing mechanism 44 and thence to a drum 27A or 28A according to which of the drums is to be used.
The requisite 'slack length' is formed in the chamber 2A and the end of the strip 3 is engaged with the requisite drum. The motor 34 is started. It is of course assumed that material is available from the supply.
Provided that the various conditioms mentioned above arise the 'slack length' will droop into the chamber 2A to a position in which the lowermost part thereof is above the lower level 22:
The position of the lowermost part of the 'slack length' is monitored by the photoelectric detection system 20 which will be producing a first control output. In addition, the length detector 17 will be measuring the amount of strip material fed through the chamber 2A and will be producing a second control signal output. At the same time the traversing mechanism 44 will be laying the strip material onto the drum in successive layers.
It will be understood that at any time only one drum 27A or 28A will be receiving strip material.
During the winding operation there will be a progressive change in the rate of feed of the strip material from the chamber 2A as a result of the progressive increase in the effective diameter of the drum as more and more material is laid onto the drum in successive layers. This progressive feed rate increase is accommodated during winding by the shortening of the 'slack length' as is shown in Figure 1 in which the full line shows the starting droop shape of the 'slack length' and the dashed line 3A shows the droop shape of the 'slack length' during a later stage of the winding operation. It will be understood that as the diameter on the reel or drum continues to increase the diameter can be monitored by sensing means and the feed rate adjusted to take into account the diametrical change. Alternatively, the feed rate can be modified according to the overall length of strip material fed through the chamber 2A.
As has been mentioned above during its passage through the chamber 2A the 'slack length' bears against the inclined back plate 7 and in particular against the surface 18. This contact is restricted to a contact between the edge or edge region of the strip material and it has been found that this co-operation acts in such manner as not only to prevent any twisting or distortion of the strip material but also to considerably reduce tension in the material being wound.
These results have been found to be maintained when winding a wide variety of strip material cross sections and profiles and through out a wide range of sizes from, for example, one millimetre diameter to several hundred millimetres in width.
A further important factor arising from the contact effected between the surface 18 and the strip material edge is that the 'slack length' is not able to move sufficiently out of its intended path to lie outside the optical paths and thus give rise to spurious signals which could lead to unrequired adjustments to the winding and/or feed rates.
It should be noted that the above mentioned factors relate to the winding of material on a drum carried by either shaft so that if necessary a single shaft arrangement could be constructed.
Figure 5 schematically shows in block diagram form the broad details of electric and electronic arrangements for enabling the control of the motor drive to the shafts 27 and 28 in response to the output signals from the photoelectric detection system 20. As will be seen the output signals from the detection system feed into an electronic decoding logic unit 51 which serves to identify which of the photoelectric detectors 23 and 25 has been caused to vary its output signal in consequence of movements of the lowermost part of the 'slack length' 3A relative to the upper and lower levels 21 and 22. The decoding unit 51 produces an output signal which is fed to the motor control unit 52 which has an output signal which controls the actual operation of the motor 34.
The length sensor 17 produces an output which is representative of the instantaneous amount of strip material 3 that has been fed through chamber 2A.
A strip length required signal, which is selectively established in a length amount presetting unit 53 produces an output signal characteristic of the amount of strip material that is to be wound onto a drum. This latter signal is compared with the instantaneous length signal in a comparator 54 which is effectively a counter type comparator. This comparator 54 produces a control signal which is applied to the motor control to cause the latter to stop drive to the shaft 27 or 28 by operation of the clutches as required.
A motor drive accelerator control 55 is provided for over-riding the control exerted by the photoelectric detection system 20, this control providing the facility that an operator of the winding installation can wind in any excess material that may accumulate during the time period required to replace a full drum or the like with a fresh drum or the like.
This particular time period is in fact considerably reduced in practice by the provision of the upper and lower winding shafts 27 and 28 since the shaft for the time being not actually winding can be pre-fitted with an empty drum or the like thereby reducing changeover time to that required to cut the strip and join the strip and to the new drum on the other shaft.

Claims

1. A method of controlling the winding of strip material onto an arbour, drum, former, reel or the like by guiding the strip material (3) by way of spaced apart guide means (13,15) so located with respect to each other as to allow a length of the strip material to droop catenary like between the guide means to provide a slack length in the strip material, and by controlling the material-travel between the guide means so that the lowermost level of the slack length is maintained between two levels (21, 22) one above the other, characterised in that the strip material (3) whilst in the slack length (3A) is guided by an edge or edge region (19) thereof cooperating with a further guide means (7) presenting a working surface (18) which is inclined to the vertical.

2. A method as claimed in claim 1, and characterised in that the strip material (3) is guided at the slack length (3A) inlet end by a sole material support roll or the like (13) and from the draw-off end by a further sole material support roll or the like (15), and in that whilst the material is passing through the slack length (3A) it is supported solely by the contact of the edge or edge region (19) with the working surface (18) irrespective of the length and profile of the slack length (3A).

3. Apparatus for controlling the winding of strip material from a supply thereof onto an arbour, drum, former, reel or the like, including spaced apart guide means (13, 15) so located in the feed path of the material (3) from a supply thereof to a drum or the like, as to permit a length of the material to droop catenary like between the spaced apart guide means to provide a slack length in the strip material, means (23-26) for controlling the rate of travel of the strip material through the slack length so that the lowermost level of the slack length is maintained between two levels (21, 22) one above the other, characterised in that further guide means (7) are provided for presenting an inclined guide surface or the like (18) to an adjacent edge or edge region (19) of the strip material (3) whilst it is in the slack length (3A).

4. Apparatus for controlling the winding of strip material as claimed in claim 3, and characterised in that the further guide means (7) includes a plate or other surface (18) which is inclined to the vertical in a fixed or selectively variable manner, and in that the spaced apart guide means comprises rolls (13,15) whose axes are arranged to be normal to the working surface.

5. Apparatus for controlling the winding of strip material as claimed in claim 3 or 4, and characterised in that the means for controlling includes monitoring means comprising a photoelectric emitter (24) and detector (23) combination at the upper level (21) and an emitter (26) and detector (25) combination at the lower level (22) the arrangement being such that for acceptable winding conditions the lowermost part of the slack length (3A) interrupts the light path between the upper emitter (24) and the upper detector (23) and allows a light path between the lower emitter (26) and the lower detector (25), in that if the slack length (3A) increases in size sufficiently for the lowermost part thereof to interrupt the combination (25, 26) at the lower level (22) the winding conditions are changed to remove the interruption, and in that in the event that the slack length (3A) decreases in size to the extent that the lowermost part thereof lifts above the upper level (21) the interruption of the combination (23, 24) at the upper level (21) is removed and the winding conditions are changed to bring the lowermost part of the slack length below the upper level (21).