Textiles: weaving – Fabrics – Drier felts
Reexamination Certificate
2000-09-18
2001-12-11
Falik, Andy (Department: 3765)
Textiles: weaving
Fabrics
Drier felts
C198S844200, C024S03300F, C024S03300F
Reexamination Certificate
active
06328079
ABSTRACT:
FIELD OF THE INVENTION
The invention concerns a belt for recirculation in machines, for example in paper machines, having at least two elongated coupling elements, extending in the transverse belt direction, which have coupling loops on the mutually facing sides, such that the coupling loops of two coupling elements can be caused to overlap so as to result in a passthrough channel, extending in the transverse belt direction, through which a coupling wire can be inserted.
BACKGROUND
Especially in machines in which webs or films are transported, for example in paper machines, long and wide belts which recirculate in the machine and in that context support the webs or films are used. In paper machines these are predominantly textile felts or wires whose base is a woven or knitted fabric. One or more fiber layers are then needle-felted onto that base in order to manufacture felts. Felts of this kind are used in particular in the press section of a paper machine, whereas wires are utilized in the sheet-forming region and in the dryer section.
SUMMARY OF THE INVENTION
In many cases the belts are not endless but rather are manufactured at a specific length. The ends are then connected together via a seam, either before being introduced into the machine or only in the machine itself In this context, the so-called inserted-wire seam has proven successful over time. With this seam, there are provided at the mutually facing ends of the belt a plurality of spaced-apart coupling loops that, for closing purposes, are caused to overlap so as to form a passthrough channel, extending in the transverse belt direction, that is enclosed alternatingly by the coupling loops of the two ends. A coupling wire, which connects the two ends of the belt in the manner of a hinge, is then inserted into this passthrough channel. Several coupling wires can also be provided parallel to one another.
A number of systems are known for configuring the coupling loops. In U.S. Pat. No. 4,344,209 and DE-A-2 256 244 (FIGS.
9
and
10
), the coupling loops are formed by U-shaped clips that hook into the ends of the belt. The seams produced by way of these coupling loops are referred to as clipper seams. It is also known, from U.S. Pat. No. 3,972,105, to form each coupling loop by way of a U-shaped sheet-metal element, the limb of each sheet-metal element being connected to the associated end of the belt. A plurality of cutouts are shaped into the sheet-metal elements to create coupling projections with the coupling loops, the coupling projections and the cutouts being complementary to one another.
The seam forms described above have for the most part been replaced by inserted-wire seams, in which the respective coupling loops are formed by a coupling coil extending beyond the belt ends (cf. DE-A-2 256 244, U.S. Pat. No. 4,574,435, EP-B-0 185 907, EP-A-0 564 436). The connection between the coils and the ends of the belt is accomplished either by way of particular seam threads or by way of the longitudinal threads of the belt itself, which wrap around the turns of the coil. An inserted wire can additionally be inserted into the coil at the wrap-around points. To couple the ends of the belt, the coils can be caused to overlap so as to form a straight passthrough channel through which the coupling wire can then be pushed.
Also known, in particular for use in the dryer section of a paper machine, are so-called wire element belts in which the entire belt is constituted by coils, extending in the transverse direction, which overlap one another in such a way as to create passthrough channels into which coupling wires can be slid (cf., for example, EP-A-0 171 891). As an alternative to the coils, it has been proposed to provide a plurality of links (cf U.S. Pat. No. 4,469,221) or oval rings (cf. EP-A-0 763 623, WO 99/16966) arranged next to one another, which connect the coupling wires to one another. Lastly, DE-A-37 35 709 proposes to configure the coupling elements as elongated shaped elements, made of plastic and extending in the transverse belt direction, which have coupling loops that wrap around the coupling wires.
The known inserted-wire seams are, like the clipper seams, usable only to a limited extent, or (as in the case of the coupling coils) present difficulties in terms of being overlapped at the correct pitch, especially if the belt is more than 10 m wide. In addition, the strength of such inserted-wire seams is not always sufficient to meet stringent requirements.
It is therefore the object of the invention to configure the coupling elements in a belt of the kind cited initially in such a way that a high-strength inserted-wire seam can be produced in simple fashion; and that it also accordingly becomes easier to manufacture a belt that is assembled exclusively from coupling elements connected by way of coupling wires. A further object is to make available a suitable manufacturing method.
The former object is achieved, according to the present invention, in that the coupling elements are configured as coupling sleeves that, in order to form the coupling loops, have cutouts which are configured complementarily to the coupling loops of the respective adjacent coupling sleeve and into which they fit in the coupled state. According to the invention, the coupling elements are thus manufactured from sleeve-like structures into which gap-forming cutouts are shaped on at least one long side, thus creating the coupling loops. Because of the complementary configuration of the cutouts and coupling loops, the latter can, as in the case of the known inserted-wire seams, be caused to overlap to form a passthrough channel, so that a coupling wire can be inserted through the coupling loops to connect the coupling elements and thus the ends of the belt to one another. In this context, the cutouts can be adapted as desired to particular requirements so that the coupling loops can easily be caused to overlap at the proper pitch even with very wide belts, so that the coupling wire can be slid through easily and quickly.
The sleeve shape imparts high strength to the coupling elements. The mechanical and chemical properties can be adapted to particular operating conditions by way of a corresponding choice of material, i.e. materials can be used that ensure good abrasion resistance, elasticity, dimensional stability, etc. The same applies to the chemical properties.
In addition, the cutouts can be provided in such a way that the permeability in the seam region differs little from that in the remaining region of the belt, i.e. in this respect as well, there is great freedom in the design of the coupling elements. The flexibility of the coupling elements furthermore ensures that the seam region adapts well to the press and reversing rolls and to the web that is being transported.
In an embodiment of the invention, provision is made for the belt to have at least one pair of adjacent coupling sleeves, i.e. in this case the coupling sleeves are used only to form one or more inserted-wire seams, while the remainder of the belt is configured conventionally, for example as needle felt with a base woven or knitted fabric, or as a sieve fabric. In this case provision is made for the pair or pairs of coupling sleeves to have cutouts and coupling loops only on the mutually facing long sides, and for the coupling sleeves to be connected to the remainder of the belt via threads that surround the cutouts. It is advantageous in this context that reinforcing wires, which are also surrounded by the threads, are additionally placed into the coupling sleeves.
As an alternative to this, provision can be made for the pair or pairs of coupling sleeves to have cutouts and coupling loops on both long sides, and for coupling wires, which are connected to the remainder of the belt by way of threads which surround them, also to sit in the coupling loops on the long sides facing away from one another. In both cases, the threads can be additional seam threads. It is more advantageous, however, if the threads used are the longitudinal threads extending in the remai
Falik Andy
Liniak, Berenato, Longacre & White LLC
Thomas Josef Heimbach Gesellschaft mit beschrankter Haftung & Co
LandOfFree
Seam for a belt for recirculation in machines, and method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Seam for a belt for recirculation in machines, and method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seam for a belt for recirculation in machines, and method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2583921