Winder for winding a traveling paper web

A winder for winding a traveling paper web. Two king rolls form a winding bed for accommodation of a paper roll, and a revolving support belt loops around the paper roll on part of its circumference. The support belt is arranged between the two king rolls, and is backed by a backing element adapted to be forced on it. The support element features a support surface on which the support belt slides and whose radius is variable in accordance with the radius of the paper roll.

BACKGROUND OF THE INVENTION 
The invention relates to a winder for winding a traveling web, wherein two 
king rolls form a winding bed for accommodating a paper roll. A revolving 
support belt loops around the paper roll, over part of its circumference. 
In winding webs, the winding hardness is a significant factor for further 
processing. Particularly with paper webs it is very important for the 
winding hardness to have a specific progression across the entire paper 
roll diameter. 
In general, the winding hardness should drop from a certain initial value 
to a final value. The drop should be maximally uniform from the first to 
the last layer. The drop should have a certain gradient, that is, should 
not be too heavy and not too light. The progression of the winding 
hardness should not at any rate include jumps, for instance a sudden drop. 
This can be accomplished only by specific measures. When letting things 
go, the line pressure between the paper roll and the king roll(s) becomes 
ever greater, and with it also the winding hardness. 
A winder of this general type is known from DE 38 39 244. This winder 
features three king rolls. The first is stationary while the following two 
are movable and looped by a support belt. The support belt and the 
positional change of the second and third king roll serves to control the 
winding hardness across the entire paper roll diameter. The objective for 
the support belt is to provide a maximally large support surface in order 
to reduce the surface load. This winder is extremely expensive. In 
addition, it has a particularly grave disadvantage: once the paper roll 
has grown such that it is carried primarily by the support belt, strong 
vibrations may occur in the support belt, as a result of which the paper 
roll starts "dancing" and can be catapulted out of the winding bed. 
Other measures for influencing the winding hardness are distributing the 
load of the paper roll among the individual king rolls. For that purpose, 
king rolls of equal diameter have been arranged already in different 
horizontal planes, or king rolls with different diameters were used. It is 
also known that winding on a king roll with a smaller diameter will 
produce a harder paper roll than winding on a king roll with a larger 
diameter. 
Known from DE-DM 7 310 606 is a winder featuring two king rolls of equal 
size. One of them can during the winding operation be lowered from an 
upper position above the horizontal plane of the axis of the other king 
roll at the beginning of the winding operation. The objective of this 
lowering is to obtain a firmly wound core from the outset. 
U.S. Pat. No. 2,461,387 describes a winder that includes two powered king 
rolls of different diameters. The one with the smaller diameter has a 
coating with a greater coefficient of friction and is powered at a higher 
speed than the other king roll, thereby exerting a tension on the outer 
layer of the web. 
DE-OS 27 57 247 concerns a winder with king rolls of the same diameter. The 
winding hardness is controlled by variation of the mutual spacing of the 
king rolls. 
DE-PS 678 585 describes a winder with two king rolls of which the first has 
a hard shell and the second a soft shell. The axes of the two rolls are 
situated in one and the same horizontal plane. 
DE-A-44 02 624 shows and describes a winder where the space bounded by the 
king rolls and the paper roll is fashioned as a pressure-tight chamber 
with a port for compressed air. Air volume and air pressure can be 
controlled in keeping with the growing weight of the paper roll. However, 
this involves appreciable problems in sealing the pressure chamber. 
The problem underlying the invention is therefore to configure a winder of 
this general type in such a way that a controlled winding hardness is 
achievable across the winding diameter, that the diameter of the 
individual paper roll can be chosen still greater than heretofore, without 
inviting the feared busting of the outer turns of the paper roll, and 
that--most of all--air inclusions between the paper roll layers will be 
avoided. 
SUMMARY OF THE INVENTION 
This problem is solved by the features of the present invention. In the 
present invention, the support belt is arranged between the two king 
rolls, and the support belt is backed by a support element adapted to be 
forced on it. The support element features a support surface on which 
slides the support belt, and whose radius is variable in accordance with 
the radius of the paper roll. 
From the great number of winders with an immeasurable variety of individual 
features, the inventor has chosen the inventive combination of features. 
The inventor recognized that the two king rolls each possess a 
considerable mass that can vibrate while rotating, thereby impairing the 
winding result. Arranging, in consequence thereto, a support element 
between the two king rolls contributes appreciably to solving the problem. 
The support element is movable toward the support surface, but forms a 
relatively rigid and thus vibration-damping unit. Support belt and support 
element may be configured in the manner of a so-called shoe press, known 
as such in the paper machine field.

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 shows schematically in simplified form a winder with a first king 
roll 1, a second king roll 2 and a paper roll 3 borne by these two king 
rolls. The paper web 4 approaches from the left in the drawing. It runs 
thus from below onto the king roll 1, loops around it across a stretch of 
about 150.degree. and proceeds then onto the paper roll 3. FIG. 1 shows 
the starting phase, during which the paper roll 3 still has a relatively 
small diameter. 
FIG. 2 shows a phase wherein the paper roll 3 has considerably grown in 
diameter. The two king rolls 1, 2 are movable relative to each other, in a 
way such that their mutual spacing is variable. Presently, the king roll 2 
is movable in the direction of arrow A. 
FIG. 2 also depicts a support unit comprised of a support belt 10, support 
element 11 and a power unit 12, with the support belt 10 sliding on the 
support element 11. Generally, a lubricant will be injected between the 
support surface of the support element 11 and the inside surface of the 
support belt 10. The support belt 10 may be provided with a drive of its 
own, but it is also conceivable that it is entrained by the rotating paper 
roll 3. Reference is made to the rotational arrows. The configuration of 
the support element 11 and the power unit 12 will be further addressed 
hereinafter. 
The structure of the present winder is such that the entire support unit 
10, 11 and 12 can after appropriate spreading of the king rolls 1, 2 
retract into the space in between. The advantage of this is that support 
by the support unit can be provided at the decisive moment, namely once 
the paper roll 3 has reached a certain diameter. 
FIG. 3 shows the winder according to FIG. 1 and 2, in an end phase in which 
the paper roll has reached its greatest diameter. 
An alternative embodiment is illustrated in FIG. 4. Greatly simplified 
again, the upper part of the figure depicts schematically a winder with 
the king rolls 1 and 2, with the support unit comprised of support belt 
10, support element 11 and power unit 12. This embodiment features the two 
following particulars: 
The two king rolls 1, 2 are situated quite distinctly above the support 
unit 10, 11, 12. The longitudinal axes of the two king rolls 1, 2 are 
situated above the axis of the paper roll 3. 
There is also the option of raising the two king rolls 1, 2 or lowering the 
support unit 10, 11, 12 as the paper roll 3 grows. 
It is understood that raising the two king rolls 1, 2 need not proceed 
exactly vertically, but that it may include also a component of movement 
toward the two sides in the fashion of a mutual spacing. The support unit 
10, 11, 12 may be lowerable into a floor recess. This option may serve to 
lower the support unit into the floor as the diameter of the paper roll 3 
increases, such as indicated in the bottom part of FIG. 4. 
FIG. 5 shows again the support belt 10 that makes direct contact with the 
last layer of the paper roll 3 (not illustrated here). In this case, the 
support element is formed of a flexible foil 11.1 and an elastomer support 
shoe 11.2. The latter encloses a pressure chamber 11.3 and features--not 
illustrated here--a port for introduction of a fluid medium, for instance 
air. The radius R of the support surface formed by the flexible foil 11.1 
allows thus variable adjustment. 
As can be seen furthermore, the flexible foil 11.1 attaches to the 
elastomer support shoe 11.2 at a fixed point 11.4, as shown at the 
right-hand part of the illustration. But the foil rests otherwise loosely 
on the outer contour of the elastomer pressure shoe, so that the foil 
allows deformation. 
In the embodiment according to FIG. 6, the support element is formed of a 
fixed box 11.5 and of a flexible foil 11.1, the latter consisting, e.g., 
of plastic or metal. The foil is hinged to a wall of the box 11.5 by means 
of a hinge 11.4. 
FIG. 7, scaled up, shows a support element 11 of a special kind. This 
particular embodiment consists of a material having properties equal or 
similar to hard rubber. Evident again is the radius R of the support 
surface 11.6 of the shoe. 
The power unit 12 is presently comprised of two rigid levers 12.1, 12.2 
joined rigidly to the support element 11 by way of rigid corners 12.3, 
12.4. The two rigid corners 12.3, 12.4 are located in the two end areas of 
said support element 11. But their arrangement could as well be somewhat 
closer than illustrated here. 
Visible, furthermore, are a piston 12.5 and a cylinder 12.6. Coordinated 
with these two elements are two rods 12.7, 12.8 that are hinged to the 
levers 12.1, 12.2. The power unit can be actuated by introduction of a 
pressure medium in the space of cylinder 12.6, either on the one or the 
other side of piston 12.5, so that the two levers 12.1, 12.2 will be acted 
upon accordingly by way of the joints. In turn, this causes a bending of 
the support element 11, either in the sense of enlarging or reducing the 
radius R, in accordance with the radius R of the paper roll, not 
illustrated here. 
A very essential idea consists in fashioning the cross sectional profile 
illustrated here, of the support element 11, such that the support surface 
11.6 proceeds steadily along a circular arc, since also the periphery of 
the paper roll is always circular. There are also other options to achieve 
just that, for instance by using appropriate packings of other material in 
the flesh of the support element. The principle applied is the same as in 
retaining rings (so-called Seger rings) that are known from the field of 
general mechanics. 
It is understood that the longitudinal axes of both king rolls 1, 2 may 
both be situated in a horizontal plane and arranged at a mutual offset. A 
favorable embodiment provides for arranging one of the two king rolls, 
namely the one onto which runs the approaching paper web 4, with its upper 
apex below the upper apex of the other king roll 2. Also, the king roll 1 
onto which the paper web runs has suitably a substantially softer shell 
than the other king roll 2.