GB1596517A

GB1596517A - Method of and apparatus for joining the strip of an expiring reel to the strip of a new reel

Info

Publication number: GB1596517A
Application number: GB5125477A
Authority: GB
Original assignee: Hauni Werke Koerber and Co KG
Current assignee: Koerber AG
Priority date: 1970-05-12
Filing date: 1977-12-09
Publication date: 1981-08-26
Also published as: DE2655791C2; DE2655791A1

Description

(54) METHOD OF AND APPARATUS FOR JOINING THE STRIP OF AN EXPIRING REEL TO THE STRIP OF A NEW REEL (71) We, HAUNI-WERKE KÓRBER & Co. KG., a German Company, of Kampchaussee 12-22, 2050 Hamburg 80, Germany (Fed. Rep.), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a method of and apparatus for joining the strip of an expiring reel to the strip of a new reel, for example in a machine of the tobacco processing industry, and, more particularly, the invention is concerned with an improvement in or modification of the invention of our Patent Specification No. 1351232.

According to a first aspect of the main invention as defined in said Patent No.

1 351 232, a method of joining a strip of an expiring reel to a strip of a new reel comprises guiding the strips to be joined in spaced relationship through a joining zone, in which a bilaterally adhesive strip is held ready between and spaced from said strips, the strip from the new reel is accelerated to a speed equal to or less than the speed of the strip from the expiring reel whereupon the strips and adhesive strip are pressed against one another to join the strips together and the portion of the strip from the expiring reel upstream of the joint and the portion of the strip from the new reel downstream of the joint are each automatically cut off.

According to a second aspect of the main invention apparatus for joining a strip from an expiring reel to a strip of a new reel comprises respective guide means for guiding the strips to be joined in spaced relationship through a joining zone, drive means for moving the strip from the expiring reel, drive means for accelerating the strip from the new reel to a speed equal to or less than the speed of the strip from the expiring reel, holder means for holding a bilaterally adhesive strip in said joining zone between and spaced from said strips, means for pressing the strips and the adhesive strip against one another to join the strips together, means for automatically cutting off the portion of the strip from the expiring reel upstream of the joint and means for autmatically cutting off the portion of the strip from the new reel downstreamof the joint.

The embodiment of the main invention described in Patent Specification No. 1 351232 by reference to the drawings thereof involves joining the two strips together when the strip from the new reel has reached a predetermined speed somewhat below the speed of the strip from the expiring reel. Accordingly, on completion of the joining operation the strip from the new reel is abruptly accelerated to the speed of the strip from the expiring reel. This has hitherto not caused any problems in tobacco processing machines because on the one hand the strip material used in the tobacco processing industry was of sufficient tensile strength to withstand the acceleration forces and on the other hand the speed differential between the strips at the moment of joining was so low that the strip material could absorb the peaks of tensile stress at the time of abrupt acceleration without damage. The speed differential served a useful purpose in the main invention because it enabled the portion of the strip from the new reel downstream of the joint to be applied to a fixed cutter in such a way as to produce automatic cut off of this portion.

Since the time of the main invention there has been an increasing tendency in the tobacco processing industry to use more porous strip material having a tensile breaking strength less than that of the strip material previously used. The object of the present invention is therefore to provide an improvement in or modification of the method and apparatus of the main invention whereby strip material of relatively low tensile strength can nevertheless be satisfactorily joined.

According to a first aspect of the present invention there is provided a method of joining a strip of an expiring reel to a strip of a new reel, comprising guiding the strips to be joined in spaced relationship through a joining zone, in which a bilaterally adhesive strip from the new reel is pulled through the joining zone so as to accelerate it continuously under tension up to a speed equal to the speed of the strip from the expiring reel whereupon the strips and adhesive strip are pressed against one another to join the strips together, and the portion of the strip from the expiring reel upstream of the joint and the portion of the strip from the new reel downstream of the joint are each automatically cut off, in the case of the downstream portion after releasing the tension therein.

The release of tension in the downstream strip portion could for example be achieved by rapid deceleration of the strip from the new reel at the appropriate time. However, the tension must be released very quickly and to this end it is provided according to a preferred feature of the invention that the release of tension on the downstream strip portion is achieved by altering the feed path of said portion.

Preferably, a first signal is formed dependent on the speed of the strip from the expiring reel, a second signal is formed dependent on the speed of the strip from the new reel, the two signals are compared and a control signal is formed for initiating the joining operation when the speeds correspond.

Advantageously, the release of tension in said downstream strip portion takes place automatically after initiation of the joining operation.

Preferably, during acceleration of the strip from the new reel, the tension therein is kept constant.

According to a second aspect of the present invention there is provided apparatus for joining a strip from an expiring reel to a strip of a new reel, comprising respective guide means for guiding the strips to be joined in spaced relationship through a joining zone, dive means for moving the strip from the expiring reel, drive means downstream of the joining zone for pulling the strip from the new reel through the reel joining zone so as to accelerate it continuously under tension up to a speed equal to or less than the speed of the strip from the expiring reel, holder means for holding a bilaterally adhesive strip in said joining zone between and spaced from said strips, means for pressing the strips and the adhesive strip against one another to join the strips together, first means for automatically cutting off the portion of the strip from the expiring reel upstream of the joint, second means for automatically cutting off the portion of the strip from the new reel downstream of the joint, and control means for releasing the tension in the downstream portion prior to cutting thereof.

Preferably, the control means are constituted by a position adjustable guide roller for the new strip, which is located between the second cutting means and the drive means for the strip from the new reel.

The guide roller is preferably mounted on a movable support held against the action of a tension spring by releasable locking means.

The locking means is preferably arranged to be released by the pressing means.

Preferably, a first measuring device is provided for monitoring the speed of the strip from the expiring reel, a second measuring device is provided for monitoring the speed of the strip from the new reel, and the two measuring devices are connected to a comparison arrangement which is connected to control means for operating the pressing means.

The drive means for the strip from the new reel preferably comprise frictional pulling means, a drive motor for driving the pulling means and a regulating arrangement for keeping the torque of the drive motor constant according to a reference value pre-set by a reference value transmitter.

The invention is described in detail hereafter with reference to the drawing showing one embodiment.

The arrangement according to the invention consists essentially of a reel-changing device 1 with bearings 2a and 2b for a reel 3a, 3b respectively as well as associated circuit arrangements 4a, 4b and a splicing device (connecting means) 6 with an associated circuit arrangement 7.

The reel-changing device 1 comprises a support 9 able to be tilted about a pivot 8 in steps of 180' and able to be locked in the position shown, on which support the bearings 2a and 2b are mounted to rotate on shafts 1 la, 1 lb. Rollers 13a, 14a, 16a, 17a or 13b, 14b, 16b, 17b are provided for guiding strips 12a and 12b from the reels 3a, 3b, the strip 12a from the reel 3a which is just coming to an end being guided around the roller 17a and the roller 16a remaining free, whereas the strip 12b from the replacement reel 3b is guided around the roller 16b and the roller 17b remains free. The joint use of the rollers 16a or 17a, 16b or 17b respectively depends on the position of the support 9 and changes automatically as the support 9 tilts.

The rollers 14a amd 14b are constructed as compensating rollers by being mounted on a lever 18a, 1 8b respectively, which is mounted on the support 9 by a shaft l9a, l9b respectively. Engaging the levers 1 8a and 1 8b is a tension spring 21a, 21b respectively so that the strips 12a, 12b are held under tension by the rollers 14a, 14b.

The shafts 1 la and 1 lb of the bearings 2a, 2b are components of braking torque generators in the form of d.c. motors 22a, 22b screw on to the rear side of the support 9, which motors are connected to the circuit arrangements 4a, 4b constructed as regulating arrangements for keeping their armature currents constant according to a predetermined reference value. The rollers 14a and 14b serve as monitoring devices 23a, 23b for the tensile stress in the respective strip 12a, 12b, in that they act by way of the levers 18a, 18b and the shafts 19a, 19b as control means on a respective reference value transmitter in the form of a rotary potentiometer 24a, 24b actuated by the shaft 1 8a, 1 8b, which potentiometers are located on the rear side of the support 9. The rotary potentiometers 24a and 24b are likewise components of the circuit arrangements 4a, 4b, which also respectively comprise a reference junction 26a, 26b, a control arrangement 27a, 27b consisting of a current regulator 28a, 28b and a power amplifier 29a, 29b as well as a shunt 3la, 3lb in the armature circuit. (In place of a d.c.

motor, a generator with known regulation of its armature current to a constant value, for example by controlling shunts in the armature circuit, can be used as a braking torque generator). Seated on the shafts 1 lea and 1 lb of the d.c. motors 22a, 22b is a tachogenerator 32a, 32b respectively which tachogenerators are connected to a reversing switch 33 actuated at the time of tilting of the support 9, so that by way of the latter, the tacho-generator 32a or 32b respectively associated with the reel which is coming to an end is connected to a division circuit 34 which receives a second signal from a measuring device in the form of a tacho-generator 36 of a main drive motor 37 of a processing machine which is not shown.

Drive means in the form of a pair of withdrawal rollers 38 for withdrawing the strip (12a) from the respective reel (3a) which is coming to an end can be driven by the main drive motor 37.

The division circuit 34 is connected to a comparison arrangement 39 which receives a reference value from an adjustable reference value transmitter 41. The comparison arrangement 39 sends a signal for closing a switch 42 of the circuit arrangement 7, when the output signal of the division circuit 34 exceeds the reference value of the reference value transmitter 41, which with the selected setting, occurs when the respective reel (3a) coming to an end has a certain speed ratio with respect to the pair 38 of withdrawal rollers on reaching a predetermined minimum diameter (c.f. also the Applicant's German Offenlegungsschrift 2.323.502).

The splicing device 6 (connecting station) comprises guide means in the form of guide rollers 43, 44, 45 for the strip 12b of the respective replacement reel 3b, whose end is engaged by a pair of rollers constructed as conveying means 46 for frictional pulling of the strip, which pair of rollers can be driven by a drive in the form of a d.c. motor 47. As part of the connecting means, the roller 43 is arranged in a non-movable manner. In a likewise stationary manner, the roller 45 is arranged to rotate on a shaft 76, on which a support 77 is likewise pivotally mounted, which support carries control means for releasing the tension on the strip 12b in the form of the roller 44. Engaging the support 77 are control means in the form of a tension spring 78 which is under tension, with which a stationary stop 79 for limiting the tilting movement of the support 77 is associated.

The support 77 is held in the position shown by a locking device 83 held by a tension spring 81 and able to tilt about a pivot 82.

Opposite the guide roller 43, a roller 51 is mounted on a lever 49 able to pivot about a shaft 48, as the movable part of the connecting means, the lever 49 being able to be tilted in the direction of arrow 54 against the action of a tension spring 52 by a control member in the form of-an electromagnet 53, one end of the lever located opposite the roller 51 serving to release the locking device 83. The strips 1 2a and 1 2b are guided at a distance apart between the two rollers 43 and 51, for which purpose a further guide roller 50 is mounted on the shaft 48 as guide means for the respective strip 12a coming to an end. A connecting strip 57 which is adhesive on both sides is held between the rolls 43 and 51 on a holder 56 which can be removed from a guide which is not shown. The lever 49 comprises separating means in the form of a serrated cutter 58 for cutting the strip 12a which is coming to an end, behind the connecting strip 57 and stationary separating means in the form of a serrated cutter 61, located in the region of the guide roller 50 serve for cutting the new strip 12b in front of the connecting strip 57 (seen respectively in the direction of travel of the strips).

The circuit arrangement 7 for the d.c.

motor 47 is constructed as a regulating arrangement for keeping the armature current constant according to a reference value able to be pre-set by a reference value transmitter 62. The reference value transmitter 62 is located before the switch 42, which is followed by a reference junction 63. The further construction of the circuit arrangement 7 corresponds to that of the circuit arrangement 4a and 4b, i.e. it comprises a control arrangement 64, consisting of a current regulator 66 and a power amplifier 67 as well as a shunt 68.

A control arrangement 69 for activating the splicing device 6 comprises a comparison arrangement 71 for the actuating variable (voltage) of the regulating arrangement of the d.c. motor 47, associated with which is a reference value transmitter in the form of the tacho-generator 36, operating in dependence on the speed of the strip 1 2a coming to an end and an amplifier 72 for exciting the electromagnet 53 is located thereafter. The circuit arrangement 7 thus serves as a measuring device for monitoring the speed of the new strip 1 2b, because the latter is proportional to the actuating variable of the regulating arrangement. Naturally, the speed of the new strip may also be monitored with other measuring devices, for example a tachogenerator or a timing or graduated disc on one of the guide rollers. The control arrangement 69 is synchronized with the main drive motor 47 with the conveying means 46 such that the comparison arrangement 71 emits a control signal when the speed of the accelerated new strip 1 2b corresponds to the speed of the strip 12a coming to an end.

The comparison arrangement 71 is also connected to the switch 42 of the circuit arrangement 7 in order to open the latter when initiating the splicing operation.

The method of operation of the arrangement according to the invention is as follows: when the reel 3a which is coming to an end has reached a predetermined minimum diameter, i.e. when the signal from the division circuit 34 representing the quotients of the signals from the tacho-generators 32a and 36 exceeds the reference value of the reference value transmitter 41, then the comparison arrangement 39 emits a signal, which causes closing of the switch 42, so that the reference value of the reference value transmitter 62 is now supplied to the referencejunction 63. By way of the current regulator 66 and the power amplifier 67, the d.c. motor 47 is supplied with constant armature current, whose actual value is monitored at the shunt 68 and supplied to the reference junction 63.

The reference value transmitter 62 is adjusted such that by way of the conveying means 46, the d.c. motor 47 accelerates the strip 12b and thus the replacement bobbin 3b within the shortest possible time, in that during the acceleration, the tensile stress in the strip 1 2b is kept constant, well below its tearing limit. Because the tensile stress prevailing in the strip during acceleration is considerably higher than that prevailing during normal operation, during this phase, the lever 18ab is tilted by way of the roller 14h against the action of the tension spring 21 b to the maximum extent in the direction of the roller 13b, so that the rotary potentiometer 24b does not emit any voltage, which has the result that the d.c. motor 22b produces no braking torque.

The speed of the d.c. motor 47 and the conveying means 46 is monitored by interro- gating the armature voltage which is supplied to the comparison arrangement 71, where it is compared with the voltage of the tacho-generator 36, which is proportional to the speed of the pair of removal rollers 38. If the speed of the accelerated strip 12b is equal to the speed of the strip 12a coming to an end, then the comparison arrangement 71 emits a signal, which, amplified by the amplifier 72, excites the electromagnet 53.

The latter tilts the lever 49 in the direction of arrow 54, the roller 51 pressing the strip 1 2a coming to an end againast the connecting strip 57 and the latter in turn against the strip 12b guided around the roller 43, due to which the two strips 12a and 12b are connected to each other. The serrated cutter 58 on the lever 49 thus cuts the strip 12a coming to an end behind the connecting point formed. At the time of tilting of the lever 49, its end located opposite the roller 51 tilts the locking device 83 against the action of the tension spring 81, due to which the latter releases the support 77, which is consequently tilted by the tension spring 78 towards the stop 79.

Due to this, tension on the section of the new strip 12b preceding the connecting point is suddenly released, so that it is able to form a small loop around the stationary serrated cutter 61, when the splicing point is drawn around the guide roller 50 by the strip 12a which is coming to an end. The section of the new strip 12a preceding the connecting point is cut by the stationary serrated cutter 61 directly at the connecting point and the detached section is placed in a collecting container 84.

In addition to the initiation of the aforedescribed splicing operation, the signal of the comparison arrangement 71 also brings about opening of the switch 42, so that a reference value is no longer supplied to the reference junction 63, which has the result that the d.c. motor 47 gradually stops.

The tensile stress prevailing in the strip 12b between the reel 3b and pair of withdrawal rollers 38, after the afore-described splicing operation is determined by the d.c. motor 22b, whose respective armature current (equal to the braking torque) is kept constant according to the reference value emitted by the rotary potentiometer 24b. For this, the respective actual value of the armature current is monitored at the shunt 31 b and supplied to the reference junction 26b which also receives the reference value of the rotary potentiometer 24b dependent on the tensile stress in the strip 12b. In the case of a chan'-- in the tensile stress in the strip 12b, decelet? tion of the reel 3b takes place absolutely uniformly, because the braking torque produced by the d.c. motor 22b corresponds exactly to the reference value pre-set by the rotary potentiometer 24b, thus, exactly defined ratios exist.

After the splicing operation, the holder 56 is removed from its guide, whereupon the support 9 is tilted through 180 clockwise. In this case, the strip 12b is detached from the roller 16b and placed on the roller 17b. Also, the reversing switch 33 is actuated, so that now the tacho-generator 32b is connected to the division circuit 34. The centre of the reel 3a which has come to an end is then removed from the bearing 2a and a new replacement reel is put in position. As shown in the drawing for the strip 12b, the strip of this replacement reel is now threaded-in and introduced into the conveying means 46.

Then, the holder 56 with a new connecting strip is re-introduced into its guide. The reelchanging device 1 and splicing device 6 are thus ready for the next splicing and changing operation.

The advantage of the invention consists in that sudden changes in the tensile stress at the time of withdrawing a strip and accelerating its reel as well as during the actual splicing operation no longer occur, due to which disturbances caused by tearing of the strip are eliminated. The acceleration of a replacement reel now takes place under optimum conditions, so that this operation is independent of external influences. The wastage of strip material, which is used for the acceleration of the replacement reel, can be kept low in an optimum manner.

WHAT WE CLAIM IS: 1. A method of joining a strip of an expiring reel to a strip of a new reel, comprising guiding the strips to be joined in spaced relationship through a joining zone, in which a bilaterally adhesive strip is held ready between and spaced from said strips, the strip from the new reel is pulled through the joining zone so as to accelerate it continuously under tension up to a speed equal to the speed of the strip from the expiring reel whereupon the strips and adhesive strip are pressed against one another to join the strips together, and the portion of the strip from the expiring reel upstream of the joint and the portion of the strip from the new reel downstream of the joint are each automatically cut off, in the case of the downstream portion after releasing the tension therein.

2. A method as claimed in claim 1, wherein the release of tension in said downstream portion is achieved by altering the feed path of said portion.

3. A method as claimed in claim 1 or 2, wherein a first signal is formed dependent on the speed of the strip from the expiring reel, a second signal is formed dependent on the speed of the strip from the new reel, the two signals are compared and a control signal is formed for initiating the joining operation when the speeds correspond.

4. A method as claimed in any one of the preceding claims, wherein the release of tension in said downstream strip portion takes place automatically after initiation of the joining operation.

5. A method as claimed in any one of the preceding claims, wherein, during acceleration of the strip from the new reel, the tension therein is kept constant.

6. Apparatus for joining a strip from an expiring reel to a strip of a new reel, comprising respective guide means for guiding the strips to be joined in spaced relationship through a joining zone, drive means for moving the strip from the expiring reel, drive means downstream of the joining zone for pulling the strip from the new reel through the joining zone so as to accelerate it continuously under tension up to a speed equal to or less than the speed of the strip from the expiring reel, holder means for holding a bilaterally adhesive strip in said joining zone between and spaced from said strips, means for pressing the strips and the adhesive strip against one another to join the strips together, first means for automatically cutting off the portion of the strip from the expiring reel upstream of the joint, second means for automatically cutting off the portion of the strip from the new reel downstream of the joint and control means for releasing the tension in the downstream portion prior to cutting therof.

7. Apparatus as claimed in claim 6, wherein the control means are constituted by a position adjustable guide roller for the new strip, which is located between the second cutting means and the drive means for the strip from the new reel.

8. Apparatus as claimed in claim 7, wherein the guide roller is mounted on a movable support held against the action of a tension spring by releasable locking means.

9. Apparatus as claimed in claim 8, wherein the locking means is arranged to be released by the pressing means.

10. Apparatus as claimed in any one of claims 6 to 9, wherein a first measuring device is provided for monitoring the speed of the strip from the expiring reel, a second measuring device is provided for monitoring the speed of the strip from the new reel, and the two measuring devices are connected to a comparison arrangement which is connected to control means for operating the pressing means.

Il. Apparatus as claimed in any one of claims 6 to 10, wherein the drive means for the strip from the new reel comprise frictional pulling means, a drive motor for driving the pulling means and a regulating arrangement for keeping the torque of the drive motor constant according to a reference value pre-set by a reference value transmitter.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. After the splicing operation, the holder 56 is removed from its guide, whereupon the support 9 is tilted through 180 clockwise. In this case, the strip 12b is detached from the roller 16b and placed on the roller 17b. Also, the reversing switch 33 is actuated, so that now the tacho-generator 32b is connected to the division circuit 34. The centre of the reel 3a which has come to an end is then removed from the bearing 2a and a new replacement reel is put in position. As shown in the drawing for the strip 12b, the strip of this replacement reel is now threaded-in and introduced into the conveying means 46. Then, the holder 56 with a new connecting strip is re-introduced into its guide. The reelchanging device 1 and splicing device 6 are thus ready for the next splicing and changing operation. The advantage of the invention consists in that sudden changes in the tensile stress at the time of withdrawing a strip and accelerating its reel as well as during the actual splicing operation no longer occur, due to which disturbances caused by tearing of the strip are eliminated. The acceleration of a replacement reel now takes place under optimum conditions, so that this operation is independent of external influences. The wastage of strip material, which is used for the acceleration of the replacement reel, can be kept low in an optimum manner. WHAT WE CLAIM IS:

1. A method of joining a strip of an expiring reel to a strip of a new reel, comprising guiding the strips to be joined in spaced relationship through a joining zone, in which a bilaterally adhesive strip is held ready between and spaced from said strips, the strip from the new reel is pulled through the joining zone so as to accelerate it continuously under tension up to a speed equal to the speed of the strip from the expiring reel whereupon the strips and adhesive strip are pressed against one another to join the strips together, and the portion of the strip from the expiring reel upstream of the joint and the portion of the strip from the new reel downstream of the joint are each automatically cut off, in the case of the downstream portion after releasing the tension therein.

12. A method joining a strip of an

expiring reel to a strip of a new reel, substantially as herein described with reference to the accompanying drawings.

13. Apparatus for joining a strip from an expiring reel to a strip of a new reel, substantially as herein described with reference to and as illustrated in the accompanying drawings.