Roll or roller – With heating – cooling – or heat transfer means
Reexamination Certificate
1999-05-07
2001-11-13
Hughes, S. Thomas (Department: 3726)
Roll or roller
With heating, cooling, or heat transfer means
C492S020000
Reexamination Certificate
active
06315703
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pressure treatment roller. More specifically, the present invention relates to a pressure treatment roller that may be used to treat, for example, non-woven webs, textile material webs, webs of paper, webs of card material, plastic films or metal foils. The pressure treatment roller has a roller core and a casing tube. The casing tube is supported on the roller core by a central support. A first intermediate space and a second intermediate space are disposed on both axial sides of the central support.
2. Discussion of the Related Art
Pressure treatment rollers per se are known from, for example, German reference DE-A 17 85 197. Pressure treatment rollers interact with a counter roller to form a roller gap or nip between the two rollers. A web of material is guided and squeezed (i.e., treated) through the nip. When treating a web of material, it is an object to achieve as uniform a treatment of the web as possible over the entire width of the roller. Thus, it is desirous to apply as uniform a pressure as possible to the web over the entire width of the roller.
German reference No. DE-A 14 60 290 discloses a roller where the casing tube is supported exclusively at the center of the casing tube. The casing tube is supported on the roller core over as small a part of its length as possible. Thus, the central support is designed as a supporting disk 5. Reinforcing rings 6 are distributed over the length of the casing tube, but these reinforcing rings 6 do not contact the roller core even when the casing tube is deformed during normal use, as shown in FIG. 3 of the German '290 reference.
These types of pressure treatment rollers are known in the art as uncontrolled or “passive” deflection adjustment rollers because their structural design enables them to essentially adapt to the bending line of their counter roller.
“Active” deflection adjustment rollers use hydrostatic supporting shoes to support the roller casing on a yoke. Alternatively, active deflection adjustment rollers use a floating roller. A hydraulic fluid occupies half of the hollow space inside of the roller to support the floating roller.
In an active deflection adjustment roller, it is possible to control the temperature of the roller's outer surface by heating or cooling the hydraulic fluid. The hydraulic fluid transfers (or dissipates) heat to (or from) the roller casing, so that the surface of the roller can be controlled to have a predetermined temperature. Thus, the web of material can be treated at a predetermined pressure and at a predetermined (i.e., increased or reduced) temperature. But it is preferred not to use the same hydraulic fluid to support and heat the roller casing.
In conventional passive deflection adjustment rollers there is no hydraulic medium available to use to control the temperature of the roller.
SUMMARY OF THE INVENTION
It is an object of the present invention to control the temperature of a passive deflection adjustment roller.
This and other objects are achieved in a currently preferred exemplary embodiment of the present invention by a passive pressure treatment roller where the casing tube has bores interior of its outer surface. The bores are connected to a supply of a heat transfer medium.
The roller core and casing tube are preferably integral with one another to prevent micro-frictions from occurring in the region of the bearing surface that would exist between the roller core and the casing tube if they were not integral. These micro-frictions would result from the casing tube being stretched while the roller core is compressed due to simultaneously occurring tensile and compressive stresses during deflection of the assembly during normal use. The roller core and casing tube are also preferably integral so that the supporting width can be made significantly narrower, which results in the roller having better intimate contact against the counter roller.
The supply preferably includes at least one flexible conduit that connects the casing tube to the roller core. Because the pressure treatment roller conventionally has “free” ends, it is relatively difficult to ensure a uniform charging or filling of the peripheral bores in the casing tube. If the charging were carried out via the axial center, where the casing tube and roller core are integral with one another, it would be relatively difficult to keep the temperature of the roller surface uniform throughout its entire length (e.g., during a heating mode the center of the roller would be warmer than the axial ends of the roller). In addition, it would be difficult to produce the appropriate bores in the axial center without damaging the surface of the casing tube. The at least one flexible conduit permits a heat transfer fluid to flow through the bores in the casing tube over the entire axial length of the casing tube, without any adverse effects occurring as a result of the constantly changing distance between the roller core and casing tube, which occurs during revolution of the pressure treatment roller. The conduit is sufficiently flexible so that it compensates for these dimensional changes due to its own elastic deformation.
The at least one flexible conduit is preferably a hose. Although the changes in the geometry of the roller are relatively small during operation, repeated flexural fatigue stress is better absorbed by a flexible hose than with “rigid” conduits.
Preferably, more than one flexible conduit is disposed at one axial end face. The flexible conduits can then be distributed better, so that, for example, an installation space remains at the radial center of the axial ends of the pressure treatment roller so that an operator can access the interior of the roller.
The supply includes distributor heads disposed on the axial ends of both the casing tube and the roller core. The distributor heads at each axial end are connected to one another by the at least one flexible conduit. Thus, as soon as the heat transfer medium reaches the distributor head, it is immediately distributed to the bores in the casing tube so that the medium can flow through the casing tube in predetermined bores in a predetermined direction.
In accordance with another exemplary embodiment of the present invention, the distributor head disposed on the casing tube (i.e., the outer distributor head) preferably has annular ducts, which are in fluid communication with all of the bores. One of these annular ducts is a feed duct, which is in fluid communication with some of the bores. The cross sectional area of the feed duct becomes smaller about the circumference of the casing tube starting from the inlet of the heat transfer fluid into the feed duct. The feed duct is in fluid communication with some of the bores because each of these bores has an open end that opens into the feed duct. The heat transfer medium enters into these bores at the open end of the bore. Because the cross sectional area of the feed ducts becomes smaller as you move away from the entry of the heat transfer fluid into the duct, the heat transfer fluid is distributed uniformly to all of these bores over the circumference of the roller.
Another one of the annular ducts in the outer distributor head is an outflow duct, which is in fluid communication with the remainder of the bores. The cross sectional area of the outflow duct becomes larger about the circumference of the casing tube ending at the exit of the heat transfer fluid from the outflow duct. Each of the remainder of the bores has an open end that opens into the outflow duct. The heat transfer medium exits from the remainder of the bores at its open end into the outflow duct. The feed duct and the outflow duct are separated from one another by a wall that is located in a different position about the circumference after each bore. In other words, the wall is located in a different position between each circumferentially adjacent bore. The overall cross sectional area of the feed duct combined and the outflow duct is the same
Quack Ralf
Tschirner Wolfgang
Darby & Darby
Hughes S. Thomas
Kleinewefers Textilmaschinen GmbH
Nguyen T.
LandOfFree
Pressure treatment roller does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pressure treatment roller, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pressure treatment roller will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2574097