Apparatus for Seaming Papermaker's Fabric

In the manufacture of paper, fabric belts are employed in the papermaking machines, such fabric belts may be formed from an endless loop which is woven as an endless loop or may be formed as flat segments whose ends are joined by a seam. Both methods have distinct advantages and disadvantages, typically endless belts are more complex to manufacture and more difficult to install. Installation of such endless belts or loops often requires partial disassembly of the papermaking machine for insertion. Such endless belts are employed however, because they do not have a seam which can effect product quality. Belts formed as flat segments whose ends are joined by a seam are much simpler to install in a papermaking machine. However, insertion of a pintle yarn or yarns which are employed to close the seam can be a difficult task. Also, the seam area can often result in undesirable marks on the product. Often, such pintle yarn or yarns are shaped for example flat or round having a flat side and two pintle yarns are employed one being inserted from each side of the belt. The proper alignment of the pintle within the fabric seam can be difficult to obtain, especially when pintles of other than circular cross sections are employed.

In the past, wire guides or leads have been attached to pintle yarns to assist in threading the pintle yarn through the fabric seam. Such guide wires were relatively stiff in comparison to the pintle yarn to make insertion easier. However, the attachment of a long relatively stiff guide wire to a pintle yarn results in a combination which is difficult to handle. Often, the guide wire and/or the attached pintle yarn can become tangled or kinked. Problems with tangling are especially prevalent when pintles with other than a round cross section are being employed which require a specific orientation within the seam. In order to properly orient the pintle in the seam, it is often necessary to remove the guide wire and start over, resulting in a free guide wire and pintle which easily becomes tangled or kinked.

The present invention provides an easily manipulated pintle yarn and guide wire spool apparatus for use in seaming papermaking fabric. The present invention provides an apparatus which allows an operator inserting a pintle yarn to use a guide wire which may be easily respooled during repeated insertion or withdrawal to obtain a desired orientation and further can be reused after respooling of the guide wire and pintle yarn. The present invention further provides a convenient shipping and handling apparatus for a pintle yarn guide wire combination.

FIG. 1A is a plan view of a pin seam in a papermakers fabric.

FIG. 1B is a side view taken along line B--B of FIG. 1A.

FIG. 2 is a perspective view of the present invention.

FIG. 3 is a cross section taken along line 3--3 of FIG. 2.

FIG. 4 is an enlargement partially in cross section of the swedge connection of the present invention.

FIG. 1A is a top plan view of a typical seam in a papermakers' fabric. The seam 40 connects a first end 42 of a fabric belt to a second end 44 of the belt to form an endless loop. The seam 40 forms a part of a woven base onto which unwoven batts are needled. The woven base can be a single ply as shown or can be multi-ply. The woven base comprises cross machine direction threads 45 and machine direction threads 46. The exposed ends of the machine direction threads 46 are formed into loops 47 and 48 on fabric ends 42 and 44 respectively. The loops 47 and 48 intermesh in an alternating fashion to form a substantially tubular opening through which pintle 24 is inserted to close the seam.

The present invention comprises a generally ring shaped apparatus as shown in FIG. 2. In the preferred embodiment the apparatus is approximately 8 inches in diameter. The apparatus 5 is easily held in the hand while the guide wire is being inserted in a fabric seam 40 as more fully described herein below. The apparatus 5 includes a circular element, cover 10 having a "U" shape cross section with the uprights of the "U" shape 10a and 10b being substantially parallel. The opened end 10c of the "U" shape is preferably on a radial surface of the tubular shape rather than a circumferential surface. The cover 10 includes an opening 14 which extends through the outer circumferential upright 10a of the "U" shape. The base 10d of the "U" shape, formed opposite the opened end 10c can include means to mount or grip the cover 10 such as holes 16.

A spool 20 adapted to fit between the uprights 10a and 10b of cover 10, substantially filling the space therebetween is provided. Spool 20 is a circularly shaped element preferably having a substantially "U" shape cross section with the opening 20a of the "U" shape being oriented on the outer circumferential surface. Orientation of the spool 20 within the cover 10 defines a cavity 11 adapted to receive windings of pintle yarn 24 and guide wire 26, FIG. 3.

The spool 20 preferably fits closely within the cover 10 such that relative rotation between spool 20 and cover 10 is possible but with sufficient frictional contact that spool 20 is retained within cover 10. To provide the desired close fit between cover 10 and spool 20, the dimension of the cover 10 and spool 20 are carefully controlled during molding or machining of the parts. For example, the gap between leg 10a and base 20d can preferably range from 0.005 in. to 0.01 in. and is more preferably between 0.005 in. and 0.007 in. Similarly, the gap between the distal ends of uprights 20a and 20b and upright 10b can preferably range from 0.005 in. to 0.01 in. and is more preferably between 0.005 in. and 0.007 in.

While cover 10 and spool 20 are shown as having "U" shapes in cross-section which interfit to form cavity 11, the cover 10 and spool 20 can be easily adapted to other shapes. The required shapes of spool 20 and cover 10 are such that they define a cavity 11 adapted to receive pintle yarn/guide wire combination and allow relative rotation between the cover 10 and spool 20. The shapes of spool 20 and cover 10 also expose a portion of both cover 10 and spool 20 so that it is possible to rotate the spool 20 with respect to cover 10 in either direction. Also, it is preferable that spool 20 be releasably held in position by cover 10 or vice versa.

The spool 20 is adapted to receive windings of pintle yarn 24 and guide wire 26 thereon. The pintle yarn 24 is attached at one end to the spool and wound onto spool 20 with guide wire 26 attached to the free end of pintle yarn 24 and wound about the spool concentric with the pintle yarn 24. The guide wire 26 is attached to the pintle yarn 24 by a swedge 30 which is a tubular element adapted to receive the pintle yarn 24 in a first end 30a and the guide wire 28 in a second end 30b. The swedge 30 is then crimped, as at 37 and 38, to grip the pintle yarn 24 and the guide wire 26 respectively.

A sufficient length of guide wire 26 for the width of the seam to be joined is wound about spool 20 concentric with the windings of pintle yarn 24. The free end 32 of the guide wire 30 is oriented through opening 14 of the circumferential leg 10b of cover 10 as the spool 20 is oriented in cover 10. Spool 20 may include a hole 24 or other means to assist in rotating the spool when it is oriented within cover 10.

The preferred size and shape of the apparatus 5 of the present invention provides a convenient shipping and handling apparatus for use when seaming a papermakers fabric. The ring shape of the apparatus is easily held in one hand by an operator, freeing the other hand to insert the guide wire, or to rotate the spool 20 with respect to the cover 10 to respool the guide wire/pintle yarn combination if necessary. The preferred embodiment even allows the operator to use the thumb on the hand holding the apparatus to rotate the spool 20 with respect to cover 10 to allow more freedom in directing the guide wire/pintle yarn combination through a seam 40 with the free hand. The exposed first end 32 of the guide wire 26 is typically provided with a removable protective cover 34 during shipping and handling.

In use, the present invention greatly simplifies the insertion of a pintle yarn 24 into a fabric seam 40, as in joining the ends 42 and 44 of a belt in a papermaking machine. The apparatus 5 allows for the easy storage and handling of a variety of shapes and sizes of pintle yarn with an appropriately sized guide wire.

In use, protective cover 34 of the guide wire 26 is removed and the guide wire 26 is inserted into the fabric seam to be closed. As the guide wire 26 is being inserted into the fabric seam, the wire is withdrawn from the apparatus 5 by rotation of spool 20 in a clockwise direction with respect to cover 10 either by pulling on the guide wire or by manually rotating the spool 20 with respect to the cover 10 as described above. If during insertion, it is necessary to withdraw a portion or all of the guide wire from the seam, the withdrawn wire may be easily respooled by rotating the spool 20 counterclockwise with respect to cover 10 to prevent tangling or kinking of the pintle yarn/guide wire combination.

Relative rotation between spool 20 and cover 10 is facilitated by holes 24 and 16 respectively and by a cover 10 configuration which in combination with spool 20 defines a cavity 11 yet allows a portion of spool 20 to remain exposed for manipulation. Upon insertion of the guide wire 26 into the seam, the pintle yarn 24 is pulled through the seam by the guide wire 26. The pintle yarn 24 is then cut from the spool 20 and guide wire 26 and the ends trimmed and staked in a conventional manner.

Spool 20 and guide wire 26 may be reused. If sufficient pintle yarn remains on the spool, the guide wire may be reattached with a new swedge 30 and the guide wire 26 rewound upon spool 20 for reuse. Because many end users do not have the proper equipment to reattach a new swedge 30, it is preferable to supply a spool 20 and guide wire 26 with sufficient pintle yarn 24 to fill a number of seams. For example, a spool 20, guide wire 26 and pintle yarn 24 combination may include up to three times the pintle yarn 24 length required to fill a seam. Upon inserting the guide wire 26, the full length of the pintle yarn 24 is pulled through the seam. The excess pintle yarn 24 with guide wire 26 still attached is severed and respooled. Thus, a single original manufacturers swedge attachment between guide wire 26 and pintle yarn 24 may be employed in closing a number of seams. A typical pintle yarn 24 material exhibits an abrasion resistance and tenacity such that repeated pulling through the seams has substantially no effect on the integrity of the seam closed by a pintle yarn 24 which has been pulled through a number of seams in this manner.

The close frictional contact between cover 10 and spool 20 while surface 20d of spool 20 remains exposed allows for the manipulation of spool 20 to unwind or wind the guide wire 26 pintle yarn 24 combination. For example, if during insertion the guide wire 26 into a seam, there is some problem such as misalignment, the guide wire 26 can be completely removed from the seam and easily rewound upon spool 20 and the insertion process started over. Further, the frictional fit between the cover 10 and the present invention allows the cover 10 and spool 20 to be easily separated when the supply of pintle yarn is exhausted or so that a guide wire may be attached to the pintle yarn for spooling and reuse.

It should be understood that the foregoing description is not intended to be limiting but is only exemplary of the invention which is defined in the claims.