Advancing material of indeterminate length – Threading device
Reexamination Certificate
2000-08-04
2001-12-04
Mansen, Michael R. (Department: 3653)
Advancing material of indeterminate length
Threading device
C226S101000, C242S562100, C400S613100
Reexamination Certificate
active
06325265
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 199 37 196.2, filed on Aug. 6, 1999, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a feed accessory apparatus for feeding the tail of a material web into a roll machine.
2. Discussion of Background Information
The material web is subjected to increased pressure and, if applicable, also to elevated temperature in the nips. The effects intended to be achieved hereby extend from compression of the material web to improvement of the surface qualities. To this end, it is often necessary for the material web to run through several nips in sequence. The rolls here are generally arranged in what is known as a roll stack, i.e., their axes lie in a common plane.
Before treatment of the material web can be allowed to start, the material web must be threaded into the roll machine, i.e., it must be lead through the first nip, passed it around a guide roll, lead through the next nip, etc. In the case of a paper web, this is often handled in such a way that the tail of the paper web is folded into a point which then has a certain stiffness so it can be passed through the individual nips or roll gaps. Alternatively, a narrow strip can be cut out at the end of the paper web and then guided through the calender. Once the strip has run through the calender, the paper web can be widened again.
Feeding of the paper web can be done automatically, for instance, by guide devices which are known, e.g., from EP 0 232 689 A. The disadvantage of this design, however, is that the resources required and hence the costs for the installation are very high. Moreover, accessibility of the calender during operation is drastically reduced. If tears in the paper web occur, hazardous paper jams occur and sometimes damage is caused to equipment and rolls. It is difficult to see the moving paper web. The assembly costs at roll change are high. It is very costly to swing out the complete web guide system after feeding of the web and, in most cases, this cannot be done for space reasons.
Consequently, in many situations, the paper web is still threaded in by hand even today. During the process, the calender is set to operate slowly, and the paper web is then passed from nip to nip. This is a very labor-intensive procedure, and thus time consuming. What is extremely important is that a relatively high risk of injury exists in this context. The individual operator must reach relatively far into the calender to be able to slip the paper web into the nip. Even when the rolls are running slowly, there is still the risk that the operator's hand will be pulled along into the open nip. Contusions and other injuries frequently occur in this context.
SUMMARY OF THE INVENTION
The present invention simplifies threading of a material web into a roll machine.
In the present invention, a feed accessory apparatus for feeding the tail of a material web into a roll machine is specified with a gripper head and a carrier. The gripper head has an infeed section and a discharge section and is arranged on the carrier such that it can pivot about a swivel axis between an infeed and a discharge position.
Using this apparatus, it is now possible to grasp the material web when it has passed through the nip. The infeed section is used for this purpose. Once the tail of the material web has been gripped with the aid of the apparatus, it can be held firmly, and the tail of the material web can be pulled forward to the next desired nip, where the gripper head is pivoted and the material web is let out again, i.e., such that it is slipped through the next desired nip. This results in a marked reduction in the risk of injury because it is no longer necessary for the operator's hand to enter the vicinity of the nip, i.e., the feed accessory apparatus goes there instead. So that the gripper head can fulfill both functions, i.e., gripping and pulling, as well as sliding into the nip, it pivots between two positions. As a result, it is not necessary for the gripper head to wrap around during any stage of the process.
It is advantageous for the swivel axis to be substantially perpendicular to the feed direction of the material web. If one looks at a sectional view of a roll machine in which the roll axes are substantially perpendicular to the plane of the section, the swivel axis is also substantially perpendicular to this plane. In this manner, the material web can be grasped and then, with the aid of the gripper head, can be directed parallel to the rotational axes of the rolls. Then the tail of the material web is automatically in the correct position in front of the next nip. Only a displacement parallel to the roll plane may still be necessary. Then the feed direction is “right” again.
Preferably the gripper head has a holding mechanism. With it, the material web is held reliably and in a defined position in the gripper head. This further simplifies handling of the material web tail.
In an especially preferred embodiment, a discharge section can include an accessory drive apparatus. Using the accessory drive apparatus, the tail of the material web can be pushed into the nip of the roll machine. This saves time because the material web can be propelled, specifically at the discharge, so that the length of free web that has to accommodate the thrust can be kept as short as possible. Thus, a small saving of material results in addition to the saving of time.
More advantageously, a material web travel path has an end section that runs below the accessory drive apparatus in the infeed position and runs above it in the discharge position. The material web travel path is the path that the material web follows when it passes through the threading accessory device. When the material web enters the infeed section, it will follow gravity and attempt to exit the device from the bottom. Since the end section of the material web travel path is located below the accessory drive apparatus, the material web is not hindered by the accessory drive apparatus during infeed. In contrast, when the gripper head is pivoted and is located in the discharge position, the accessory drive apparatus is located below the end sections, so the material web tail then rests upon the accessory drive apparatus. This ensures that the accessory drive apparatus can act upon the tail of the material web in the discharge position.
It is advantageous for the accessory drive apparatus to have at least one rotatably mounted roller that lies beneath the material web in the discharge position. With the aid of the rotatable roller, the material web can then be pressed against the top of the two rolls that form the nip into which the tail of the material web is to be threaded. This roll then drives the material web, while the roller ensures that the drive force which is frictionally transmitted from the roll to the material web can be essentially fully utilized to advance the material web. The tail of the material web then either proceeds directly into the nip or strikes the lower of the two rolls forming the nip, and is then pushed into the nip by this roll.
It is especially preferred in this context for an auxiliary roller that is in driving contact with the roller to be arranged beneath the roller in the discharge position. The discharge section of the gripper head can now be positioned in front of the two rolls forming the nip in such a manner that the roller rests against the upper roll with the material web between them, and the auxiliary roller rests against the lower roll. Thus the lower roll drives the auxiliary roller, which drives the roller through the driving contact, which can include, e.g., a simple frictional connection. Accordingly, the material web is driven not only by the upper roll, but also by the interaction of the upper roll with the roller. In this manner, the stress on the material web is kept extraordinarily low.
Hoffmann Reinhard
Münch Christian
Greenblum & Bernstein P.L.C.
Mansen Michael R.
Voith Sulzer Papiertechnik Patent GmbH
LandOfFree
Feed accessory apparatus and process for feeding the tail of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Feed accessory apparatus and process for feeding the tail of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Feed accessory apparatus and process for feeding the tail of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2558926