Method and apparatus for the modulated raising of the carriages of a wind-up roll in the centerless winding of webs

A method and apparatus for the centerless winding of webs has a pressure cylinder which lies on a wind-up roll, both of which are mounted on vertical movement. The vertical movement of the carriage mounting the wind-up roll is modulated by coupling the vertical movement of the pressure cylinder therewith such that the carriages follow the movement of the pressure cylinder to a degree corresponding to the momentary degree to which the wind-up roll has been wound.

BACKGROUND OF THE INVENTION 
The invention relates to a method and an apparatus for the modulated 
raising of the carriages by which a wind-up roll held on stub shafts 
inserted into its core tube is carried for vertical displacement in the 
centerless winding of webs, while a pressure cylinder lies axially 
parallelly on the wind-up roll. 
In the centerless winding of webs of paper, textiles or plastics, the roll 
being wound lies on two supporting cylinders of which at least one is 
driven in rotation. After the leading end of the web has been attached to 
the wind-up roll core tube, the supporting cylinder or cylinders are set 
in rotation thereby causing the wind-up roll lying axially parallel on 
their circumference also to rotate. To control the winding tightness, a 
pressure cylinder lies on the outer circumference of the wind-up roll 
axially parallel thereto, for the purpose of the uniform winding of the 
wind-up roll so as to prevent the formation of wrinkles. 
To prevent the wind-up roll from creeping in the axial direction and to 
achieve an accurately positioned winding of the wind-up roll, lateral 
guides are provided in which carriages can travel or be displaced 
vertically and which are joined to the wind-up roll by means of stub 
shafts inserted into the core tube. 
As the winding progresses, the axis of the wind-up roll rises, and 
especially in the case of rolls which are much narrower than the nominal 
working width of the winding machine the carriages can jam because the 
lever arm (the distance between the carriage and the end of the wind-up 
roll) is great and the stub shaft become cocked causing interference 
between the carriage and its track. 
To counteract these difficulties, it is known to make the carriages follow 
the movement of the wind-up roll through the use of an independent drive 
in the form of air cylinders or hydraulic cylinders, for example. This, 
however, is a very expensive and complex method. Furthermore, the 
carriages can still jam, because the known drives operate according to 
their own peculiar laws of motion, not according to the law of motion of 
the growing wind-up roll. 
SUMMARY OF THE INVENTION 
It is the purpose of the present invention to create a simple and 
inexpensive method and apparatus in which the carriages will not jam in 
spite of the complex law of motion of the growing wind-up roll. 
To achieve this purpose, a method and apparatus are proposed in accordance 
with the invention which permits a modulated raising of the carriages 
since the movement of the carriages is derived from that of the pressure 
cylinder such that, as the pressure cylinder moves upwardly, the carriages 
are taken up by an amount corresponding to the degree to which the wind-up 
roll has been wound. 
In this manner any cocking or jamming of the carriages in their guides is 
prevented. 
To the pressure cylinder lying on the wind-up roll there is usually 
fastened, as shown also in U.S. Pat. No. 3,373,952, a cable or chain which 
is carried over pulleys and held under tension by a power source, namely a 
counterweight, or a pneumatic or hydraulic system. As the winding of the 
wind-up roll increases, the pressure cylinder lying on it is raised up and 
the cable or chain connected to it moves under the influence of the power 
source which keeps it under tension. 
There is not a linear relationship between the upward movement of the 
pressure cylinder and the upward movement of the wind-up roll, because at 
the beginning of the winding, when the diameter of the roll is still 
small, the axis of the wind-up roll rises more rapidly than it does toward 
the end of the winding action, when the roll diameter is large. Also, in 
the course of winding the axis of the pressure cylinder is raised up by 
approximately twice the amount of the rise of the axis of the wind-up 
roll. Therefore, in an apparatus for the practice of the method of the 
invention, it is proposed that the pulley over which the cable attached to 
the pressure cylinder is passed be joined to a cam over which the cables 
are passed whose one end is attached to the carriage on which stub shafts 
inserted into the core tube of the wind-up roll are mounted, and whose 
other end is fastened to a point on the cam, at least the cable fastened 
to the pressure cylinder being held in the continuously tensed state by a 
power source. 
It is preferred that the cables be kept in the tensed state by separate 
sources of power. Furthermore, in an advantageous manner, the pulley is to 
be joined to the cam by a clutch. This makes it possible to disengage the 
cam from the pulley so that the carriages and the pressure cylinder can be 
operated separately, especially when a fresh wind-up roll is being 
inserted or in the event of any trouble.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to FIGS. 1-3, the wind-up roll 1 lies axially parallel on two 
support cylinders 2, at least one of which must be driven for rotation. 
Upon the rotation of the support cylinders 2, the wind-up roll 1 is also 
set in rotation to wind up a web of goods 3. 
To control the winding tightness, a pressure cylinder 4 lies on the wind-up 
roll 1 and is axially parrallel thereto. To enable the pressure of the 
pressure cylinder 4 on the wind-up roll 1 to be controlled, cables 5 or 
chains are fastened to the shafts of the pressure cylinder 4, and they are 
carried over pulleys 6 and 7 and their other ends are fastened to the 
diagrammatically indicated power or force sources 8, which hold the cable 
5 under constant tension. 
Each stub shaft 9, which extends into the tubular core 1' of the wind-up 
roll 1, is fastened to a carriage 10 which is disposed for vertical 
displacement in guides. To each carriage 10 there is linked a cable 11 or 
a chain which is carried around a pulley 12 and a cam 13, and is fastened 
to the latter at point 14. By means of a weight-loaded cable 15, which is 
carried around a drum 16 connected to the cam 13, the cable 11 is kept 
constantly under tension. 
The pulley 7 is best connected to the cam 13 by means of a clutch 17. The 
clutch 17, when disengaged, permits a separate upward or downward movement 
of the pressure cylinder and of the carriages 10, but when it is engaged 
it produces a tight coupling between the pulley 7 and the cam 13, so that 
the cables 11, upon the movement of the cables 5, will follow the movement 
of the latter to the degree provided by the configuration of the cam 13. 
This degree is a function of the upward movement of the axis of the 
wind-up roll 10 in relationship to the upward movement of the axis of the 
pressure cylinder 4. 
It will be appreciated that the instant specification and examples are set 
forth by way of illustration and not limitation, and that various 
modifications and changes may be made without departing from the spirit 
and scope of the present invention.