Device for exchanging a winding mandrel

The invention relates to a device for use in apparatus for winding continuously-fed material on a winding mandrel for exchanging winding mandrels without interrupting the supply of tape or sheet material to be wound. Two endless cooperating conveyors are provided to which the ends of the winding mandrels are coupled to permit the horizontal transport of an empty winding mandrel received from a store to a winding station and to a removal station after receiving a full roll. The conveyors have sets of parallel, closely spaced bars, the axes of which are arranged perpendicularly with respect to the direction of movement of the conveyors and the ends of the winding mandrels are allowed to move vertically along the gaps between the bars as the diameter of the roll of material changes on the winding mandrel.

TECHNICAL FIELD 
This invention relates to a device for exchanging a winding mandrel in an 
apparatus for winding continuously-fed sheet material on a winding 
mandrel. 
More particularly, the invention relates to a device for exchanging winding 
mandrels without interrupting the supply of tape or sheet material to be 
wound. 
BACKGROUND ART 
When winding continuously-fed tape or sheet material, e.g., paper, cloth or 
foil sheets, the problem is well known of exchanging a winding mandrel 
having a full roll of material for an empty winding mandrel without 
interrupting the supply. 
Numerous machines have been provided in the past for solving this problem. 
A storage unit has been provided ro receive the material to be wound 
during the exchange operation. Such a storage unit has been provided by 
passing the incoming material around one or a plurality of compensating 
rollers and increasing the length of the path traveled by the incoming 
material by increasing the spacing between the compensating rollers, as 
shown, for example, in German Published Patent Application No. 21 51 829, 
FIG. 1, numeral 16. The disadvantage of such a storage unit lies in the 
requirement for a comparatively expensive additional compensating roller 
device. 
It is also known, however, to carry out the exchange of winding mandrels 
without having an additional storage means. In a well-known device, the 
winding operation from a fixed roller onto a new winding mandrel which, in 
turn, lies against a drum, is conducted by carrying the sheet material 
over a sheet deflecting device shown, for example, in German Published 
Patent Application No. 27 05 776. This sheet deflecting device comprises a 
deflecting element which extends over the whole width of the sheet or tape 
and which is movable between the drum and the fixed roller, thereby 
deflecting the sheet by establishing a curve of the sheet. The 
disadvantage of this well-known device, and also the disadvantage of a 
similar device as described German Accepted Patent Application No. 21 29 
410, is that after cutting the continuously-fed sheet material to form the 
end of the material on a full roll and the subsequent starting end of the 
material to start a new roll to be wound, there is insufficient distance 
to allow the usual and static-free transport of the full roll from the 
winding station. 
To overcome this disadvantage, a device for winding long sheet or tape 
sections has been proposed in which a contact band is located above a 
conveyor belt by a distance corresponding to the diameter of the roll of 
material, said contact band running against the direction of movement of 
the conveyor belt (German Pat. No. 20 02 725). The additional conveyor 
belt is, however, a comparatively expensive and complicated device. 
Another winding machine is known from German Accepted Patent Application 
No. 19 48 453 in which, after having completed the winding of a full roll 
and after having cut the sheet material, deterioration in the tight 
winding by loosening of the roll is prevented. In this machine, rails are 
provided which are guided by rack-and-pinion gear means. 
Still another machine for the continuous winding of moving tapes in known 
which has a plurality of roll-forming wrappers. This machine comprises a 
guide for the winding mandrel which is movable on guiding rails and in 
parallel with respect to a plane established by two rolls whereby guiding 
ledges are provided at right angles to the direction of movement (German 
Published Patent Application No. 24 25 454). This multiple-roll winding 
machine requires, however, two stationary rolls and, additionally, a 
movable auxiliary roll. Moreover, for carrying out movement, complicated 
pistons, cylinders, levers and guide rods must be provided. 
DISCLOSURE OF THE INVENTION 
It is a general object of this invention to overcome the disadvantages of 
the prior art. 
More particularly, it is an object of the invention to exchange a winding 
mandrel having a large diameter full roll of tape or sheet material and an 
empty winding mandrel without interrupting the supply of the sheet 
material to be wound. 
Another object of the invention is to provide a device for the horizontal 
transport of winding mandrels to and from a winding station in which, from 
the receipt of an empty winding mandrel to the removal of a full winding 
mandrel from the winding station, the winding mandrels are precisely 
guided. 
A concomitant object of the invention is to provide a device for the 
horizontal transport of winding mandrels, allowing the supply of empty 
winding mandrels and removal of full winding mandrels from the device 
automatically. 
Still a further object of the invention is to provide a device which 
facilitates winding of a continuously-fed tape, even if the tape to be 
wound is separated into a plurality of narrow tapes, so that it is 
possible to wind a plurality of narrow tapes simultaneously. 
It is a further object of the invention to provide a transport device for 
winding mandrels which has means capable of guiding the winding mandrels 
vertically as well as horizontally.

BEST MODE FOR CARRYING OUT THE INVENTION 
Turning to the drawings, in FIG. 1a, a full roll 1 of material is 
illustrated on a winding mandrel 2. In accordance with the invention, the 
ends 3, 4 of the winding mandrel 2 are inserted between two bars 5, 6 and 
7, 8, having circular cross sections, respectively, these bars 5, 6 and 7, 
8 forming means for coupling and uncoupling the winding mandrels to 
movable, endless conveyors 9, 10 which are mounted opposite each other. As 
herein shown, the conveyors 9, 10 are constructed in the form of upper and 
lower circulating conveyor chains which move the bars along the directions 
of the arrows shown in FIG. 1a to transport the winding mandrels 
horizontally. The ends 3, 4 of the winding mandrel 2 are provided with 
lateral recesses, preferably in the form of a quarter circle, so as to 
adapt these ends to be inserted in the gap between two bars. The drive of 
the endless conveyors 9, 10 is preferably by an electrical motor 11 which 
activates one conveyor 9 directly and the opposite conveyor 10 indirectly 
by a connection including a shaft 12. By means of suitable coupling 
elements connecting the shaft 12 and the motor 11, e.g., bevel gears or 
the like, the two endless conveyors 9 and 10 may be moved synchronously 
along the direction of the arrows, thus guiding the winding mandrel 2 
precisely. Numeral 13a represents a gear wheel which is driven by a shaft 
13 which, in turn, is driven by the shaft 12. 
In one operating state the winding mandrel 2 is positioned at a winding 
station, as illustrated in FIG. 1a. When held in this position, as shown 
in FIG. 3, the roll 1 on the winding mandrel 2 is supported by rollers 30, 
31 which are driven to rotate the roll and wind the sheet material on the 
winding mandrel 2. The endless conveyors 9, 10 carry a plurality of sets 
of circular bars 5, 6, 14, 15, 18, 19, 22, 23 and 7, 8, 16, 17, 20, 21, 
24, 25, respectively, which remain as positioned in FIG. 1a while the 
sheet material is wound on a winding mandrel 2 at the winding station. In 
practice, it is, of course, possible to provide even more sets of bars 
than shown in FIG. 1a. 
At the beginning of the winding operation, the starting end of the sheet 
material to be wound is wrapped on the winding mandrel 2. Gradually the 
diameter increases of the roll on the winding mandrel 2. When the diameter 
of the roll reaches a specified diameter, it is desired to sense the 
presence of a full roll and, either manually or automatically, produce a 
signal to switch on the motor 11. The endless conveyors 9, 10 will be 
moved simultaneously by the operation of the motor 11 to transport the 
full roll 1 on the winding mandrel 2 in the direction of the inner arrows 
from the winding station of FIG. 1a to a removal position as shown in FIG. 
1b. 
When the full roll 1 on the winding mandrel 2 reaches the removal position 
shown in FIG. 1b, the bars 5, 6 and 7, 8, respectively, spread or diverge 
because of the curvature of the transition section of the path into which 
they enter. Thus, the full winding mandrel 2 may be removed from the 
endless conveyors 9, 10. A chute or slide may be provided under the 
visible end portions of the winding mandrel 2 so as to enable the winding 
mandrel 2 to roll into a storage for full wound winding mandrels. 
In carrying out the invention, to exchange a full winding mandrel 2 with an 
empty winding mandrel 26 as the full mandrel 2 is transported to the 
removal position, on the entrance side of the device an empty winding 
mandrel 26 is inserted, as shown in FIG. 1b, and coupled to the movable, 
endless conveyors 9, 10. This is achieved in the preferred form of the 
device by means of the bars 18, 19 and 20, 21, respectively, which are 
carried by the movable, endless conveyors 9, 10 along the semicircular 
transition section to the straight inner path of the conveyors such that 
they converge on the ends of the empty winding mandrel 26. The insertion 
can be carried out automatically, for example, by releasing a pawl 70, 
normally retaining the empty winding mandrels 49, 50 (FIG. 3) in a winding 
mandrel store 27. It is to be understood that it is, of course, possible 
to increase the number of sets of bars carried by the endless conveyors 9, 
10 so as to allow winding mandrels to be inserted into the movable, 
endless conveyors in different phases of the cycle of operation of the 
conveyors. The newly inserted winding mandrel 26 is moved to the winding 
station to receive sheet material in the same way as described above in 
connection with the previous winding mandrel 2. 
Referring also to FIG. 2a, the device of FIG. 1a is shown in side 
elevation. Further according to this invention, the winding mandrel 2, 
having a large diameter roll 1, is vertically guided by the parallel, 
vertical bars 7, 8, which receive the end 4 of the winding mandrel 2 
between the bars. By means of the movable, endless conveyor which has both 
an upper and a lower section, the sets of vertical bars are moved around 
the loop defined by two straight paths and the semicircular transition 
sections. Upon movement of the bars, the full roll 1 at the winding 
station is transported horizontally to the removal position at the right 
hand side of the apparatus. The shaft 13, driven by the gear wheel 13a 
which is, in turn, connected to the electrical motor 11, moves the gear 
wheel 13. The teeth of the gear wheels 13a, 13a' enter gaps in the 
conveyor 10, which is preferably a chain, to drive the conveyors 9, 10. 
FIG. 2b depicts the full roll 1 in its right hand side end position. Thus, 
FIG. 2b corresponds to Section B--B of FIG. 1b in a side elevation. As can 
be seen from this illustration, the full roll 1 can easily be removed and, 
simultaneously, a new winding mandrel 26 can easily be inserted. Shaft 13 
is omitted in this illustration. 
FIGS. 1a, 1b, 2a and 2b illustrate the principle of the vertical and 
horizontal guidance of the winding mandrel 2 only. In practice, of course, 
elements, such as pawl 70, are provided so as to prevent the sliding down 
of the winding mandrel 2 along the gap between the bars 7, 8. Such 
elements are illustrated in FIG. 3. 
FIG. 3 depicts a complete device corresponding, in principal, to the 
devices shown in FIGS. 2a and 2b, i.e., approximately corresponding to 
elevations A'--A' and B'--B', respectively, (FIGS. 1a, 1b). The large 
diameter roll 1 in its winding station, as well as in its removal 
position, is indicated in dotted lines only. The removal position is 
designated as 1' and illustrated as a dash-dot line. 
As can be seen from FIG. 3, the device includes two transportion rollers 
30, 31 which support and transport the large diameter roll 1. The drive is 
preferably a friction drive. The rollers 30, 31 are, in turn, driven by a 
motor 32 which is located beneath the rollers 30, 31. Mechanical gear 
means between the motor 32 and the rollers 30, 31 are not shown since they 
are well-known in the art. The motor 32 is provided as a main drive, 
whereas a second motor 32a serves as a transportation roller drive. Also 
provided in the device is a load sensing roller 33 which rests on the 
large diameter roll 1 and a load arm 34 is provided by means of which the 
load sensing roller 33 can be lifted and lowered. The lifting and lowering 
of the load arm is carried out by means of an hydraulic drive 35 having a 
piston rod 36 which carries a guideroller 37 for a cable wire 38 which is 
guided by this guide roller 37 and connected at one end to a fixed 
projection or the like on the base of the device. This cable wire 38 is 
also connected via further guide rollers 40, 41, 42 to the load arm 34. 
The continuously-fed sheet material 28 to be wound passes over one 
transportation roller 30 via a first and a second guide roller 43, 44, 
respectively. A compensation roller assembly 45 is also provided between 
the guide rollers 43, 44, the assembly 45 having as one component the 
roller 46 which takes a position giving an indication of the tensile 
stress or strain of the sheet material 28. An upper and a lower position 
of the roller 46 are indicated in dotted lines. The tension in the sheet 
material may serve in a well-known manner as a controlling variable for 
the speed of the winding operation, whereby this controlling variable, 
represented by an electrical voltage, is generated in a sensor associated 
with the hydraulic cylinder 47 for positioning the roller 46. 
Above the incoming path of the continuously-fed sheet material 28, a store 
48 is provided for empty winding mandrels 49, 50. From this store 48 the 
empty winding mandrels are shifted to the endless conveyors and inserted 
into the gap between the guide bars by unlocking a pawl 70. 
To direct the sheet material 28 from a full winding mandrel 2 to a new, 
empty winding mandrel 51, a transfer means, including a pressing and 
cutting device 52, is provided. This device 52 comprises an hydraulically 
movable and swingable arm 53 having an hydraulically operated cutter 55 
which can be passed between the rollers 30, 31. The end of the arm 53 has 
a roller 54 movable between a full winding mandrel 2 and an empty winding 
mandrel 51 to an upper position designated as 54'. 
To transfer sheet material from a full winding mandrel 2 to an empty 
winding mandrel 51, the endless conveyors 9, 10 are operated to transport 
a full winding mandrel 2 horizontally from the winding station shown in 
solid lines in FIG. 3 toward a removal position 1' (shown in dash-dot 
lines) at the right side of the apparatus as viewed in that Figure. The 
new empty roll 51 also is transported from the entrance position 
horizontally toward the winding station. The transfer means 53 is operated 
to insert the guide roller 54 upwardly between the transportation rollers 
30, 31 where it picks up the material 28 and forms a loop, shown in 
dash-dot lines in FIG. 3, extending around the empty winding mandrel 51. 
The cutting element 55 is operated to cut the sheet material 28 
approximately at the point 55' which allows a full roll 1 on the winding 
mandrel 2 to be removed from the apparatus at the removal position. Also, 
a new starting end of sheet material is formed. The roller 53 presses the 
new end of sheet material from above and forms a starting loop around the 
empty winding mandrel 51 by pressing a part of the material 28 adjacent 
the end against another part of the material on the entrance side of the 
empty mandrel 51. This is more clearly shown in FIG. 4, which shows that 
the new empty winding mandrel 51 is also transported by the movement of 
the conveyors 9, 10 to the winding station between the transportion 
rollers 30, 31 which begin turning the empty winding mandrel 51 to wind 
the continuously-fed material on the mandrel. 
Referring to FIG. 4, an alternative embodiment is shown of the transfer 
means 52 shown in FIG. 3. This alternative embodiment of transfer means 60 
utilizes three transportation rollers 30, 31, 61, thus avoiding having the 
arm 53 pass between the transportion rollers 30, 31. In this embodiment, 
the transfer means 60 is normally located in a position (not shown) 
beneath the rollers 30, 31 which support the roll of material at the 
winding station. 
In the state of the components shown in FIG. 4, the full roll 1 has just 
been transported away from the rollers 30, 31 and is in contact with the 
roller 61. The hydraulic cylinder 63 of the transfer means has been 
operated to pivot the arm 62 to move a roller 64 and thereby pick up the 
material 28 and form a loop to an upper position around the new, empty 
winding mandrel 51 in the manner indicated by dashed lines. The material 
28 and the countercurrent material 28' meet each other at point 65. The 
material 28' is then cut, for example, at point 66, and the full roll 1 
can be removed. The end of the material 28' will be wound around the 
winding mandrel 51 to form a starting loop for the new roll. 
Other driving means, for instance for the transport of the winding mandrels 
2, may be provided. The main condition is that these means should guide 
the winding mandrel vertically, as well as horizontally, without any 
jamming. Also, it is not necessary to provide a rigid or continuous 
winding mandrel. Instead, the winding mandrel may comprise at least one 
spring which allows the compression of the winding mandrel along its 
longitudinal axis. Thus, the winding mandrel can be inserted between the 
gap of two adjacent bars in a position as shown in FIG. 1a. In such a 
case, it would not be necessary to insert or remove the winding mandrel at 
the respective ends of conveyors 9, 10. Instead, they could be inserted 
between these ends. 
It is an important advantage of the present invention that it is possible 
to wind very large diameter rolls. Such a large roll, including a winding 
mandrel and the material to be wound, may have a diameter of 1.5 meters or 
more. For this purpose, it is necessary to provide an exact vertical 
guidance. Otherwise the winding would not be symmetrical.