Two known reeling apparatus of this type are Beloit Corporation's TNT and ATR reels. The former is disclosed in U. S Patent No. 5,370,327, and the latter is disclosed in U. S Patent Application No. 08/574,824 filed December 19,1995.

The ATR (Advanced Tissue Reel) reel was developed with a view to apply all the advantages of the TNT (Tension, Nip and Torque) reel to high bulk grades of paper, especially tissue. These grades of paper require winding at little or no nip pressure so that as much of their inherent bulk can be retained as possible. In order to attain control of very low nips, the ATR reel utilizes a large diameter reel drum on a fixed stand. Also, hydraulically controlled carriages which act as nip load controllers hold the building roll of paper against the reel drum. The nip load is measured either via load cells under the reel drum or via pressure transducers in the hydraulic. carriage loading system.

The ATR reel differs from the TNT reel in that with the TNT reel, the reel drum can be raised or lowered in elevation. This allows the paper to be transferred to the new reel spool on the wet-end side of the reel drum (upstream in the paper machine process). After winding of the paper begins, the reel spool/winding roll of paper is moved downstream by its guiding carriages. This movement requires the reel drum to move downwards to allow the winding roll of paper over the top of the reel drum. As the reel drum is of considerable weight, there is a limit to how accurately the nip can be controlled at low nip loading values while also having a large moving mass controlling the nip.

It was decided that if the reel drum was fixed on stands (i. e., its weight is supported) and the weight of the winding roll of paper is also supported on rails, then it would be easier to attain control of nip pressure at very low levels.

The problem with fixing the reel drum in position is that the whole roll winding process must now happen on the dry-end side (downstream) of the reel drum in order for any component of the nip load from being provided by the weight of the new reel spool and any web wrapped on it. This means that to allow reeling to be a continuous process, the new reel spool must at some stage be inserted between the winding roll of paper and the reel drum without breaking the sheet of paper as it winds onto the roll.

It was found that if a reel drum of 2,130 mm diameter were used with a reel spool of up to 500 mm diameter then the new reel spool could be inserted into the gap between the winding roll of paper and the reel drum at any time after the winding roll of paper exceeds 2000 mm in diameter. This was made possible by placing the reel spool support rails at such a height that the empty reel spool first contacts the reel drum at a nip point 14 degrees past top-dead- center of the reel drum. This system is applicable to any reel where the reel spool is 500 mm or less in diameter, and where the particular reeling process allows for full sheet transfer of paper from the old roll of paper to the new reel spool only when the old roll of paper is above 2000 mm diameter. Below 2000 rnm diameter, the sheet must be broken back from the reel to the last stage in the papermaking process and fed through again onto the new reel spool when it is in position.

SUMMARY OF THE INVENTION One method of overcoming the above limitation is to replace the large reel drum with a fabric belt system. The belt is supported, tensioned and guided with one part of the belt run suspended at an angle chosen to suit the reeling process. It is this angled section of belt against which the winding roll of paper is"nipped". The nip pressure is measured and controlled by sensing changes in belt tension, for example by mounting one or more of the support rolls on tension load cells.

The reel spool guiding carriages will be driven/positioned by a control system (e. g. hydraulic cylinders operating in load control). Thus, as the paper diameter wound onto the reel spool increases, nip pressure increases and the reel spool carriages move downstream in order to bring the nip pressure back to the pre-determined set-point value. Because the belt is suspended at an angle, the winding roll of paper is moved further downstream from its initial position than when nipped against a reel drum whose surface is curved.

Due to the flexible nature of the belt, the nip width is wider and thus the nip intensity lower than with a hard roll. This minimizes loss of bulk in the paper.

Using a belt as described above also makes it possible to increase the size of the reel spool that can be used with low bulk grades of paper. Instead of placing load cells under a large diameter reel drum, low nips can be sensed by measuring changes in belt tension.

More particularly, the invention provides an apparatus comprising a frame and first and second generally parallel, generally horizontal rails mounted on the frame. Each rail has an upper surface for supporting a respective end of a reel spool. The apparatus also comprises a support belt mounted on the frame for movement along an endless path, the belt having an upper run extending horizontally in the cross machine direction and extending at a non-horizontal angle in the machine direction such that the upper run is angled downwardly in the downstream direction. First and second carriages are operatively associated with the first and second rails, respectively, for longitudinal movement parallel to the rails. Each of the carriages is selectively operative to engage a respective end of the reel spool such that the reel spool moves with the carriages along the rails. A drive selectively engages and rotates the reel spool when the reel spool is engaged by the carriages. The apparatus also comprises a positioning device for (1) selectively positioning the carriages in an initial reeling position in which the web is reeled onto the reel spool engaged by the carriages and in which the upper run of the belt is in nipping engagement with the web being wound onto the reel spool, and (2) positioning the carriages downstream of the initial reeling position to control the nip pressure between the belt and the web being wound onto the reel spool during reeling of the wound web roll, whereby the wound web roll is moved downstream while being horizontally supported by the rails, rotatably driven by the drive, and nipped by the belt until the desired web roll diameter is reached.

The invention also provides a method for reeling a traveling paper web into a wound web roll on a reel spool, the method comprising the steps of: (a) supporting the reel spool for rotation and for translational movement generally horizontally; (b) rotating the reel spool so as to wind the traveling web onto the reel spool to form thereon a wound web roll; (c) providing a support belt mounted for movement along an endless path, the belt having an upper run extending horizontally in the cross machine direction and extending at a non- horizontal angle in the machine direction such that the upper run extends downwardly in the downstream direction; (d) placing the upper run of the belt in nipping engagement with the web being wound onto the reel spool; (e) maintaining horizontal support and rotation of the wound web roll and nipping engagement of the roll by the belt as the diameter of the roll increases and the roll moves downstream along the belt; and (f) controlling the nip pressure between the belt and the web being wound onto the reel spool during reeling of the wound web roll and movement of the roll along the belt.

Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings.

DESCRIPTION OF THE DRAWINGS Fig. 1 is a side elevational view of an apparatus embodying the invention.

Fig. 2 is a view showing movement of the wound web roll along the belt.

Fig. 3 is a top plan view of the apparatus.

Fig. 4 is a view taken along line 4--4 in Fig. 1.

Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways.

Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DESCRIPTION OF THE PREFERRED EMBODIMENT An apparatus 10 embodying the invention is shown in the drawings.

The apparatus 10, which reels a traveling paper web 14 into a wound web roll 18 on a reel spool 22, has a machine direction (from right to left in Fig. 1) and a cross machine direction (into and out of the paper in Fig. 1 and from right to left in Fig. 3). Many of the components of the apparatus 10 are substantially identical to components of, and are described in greater detail in, pending U. S.

Patent Application Serial No. 08/574,824, which is assigned to the assignee hereof and which is incorporated herein by reference.

The apparatus 10 comprises a frame 26 supporting a pair of spaced, parallel, horizontal rails 30 and 34. Each of the rails 30 and 34 has a horizontal upper surface 38 for supporting a respective end of a reel spool 22. The apparatus 10 has front and back sides (the right and left sides in Fig. 3), with the front side being shown in Fig. 1. The front and back sides are substantially identical, and only the components of the front side are shown in detail in Fig.

1, it being understood that the corresponding components of the back side of the apparatus 10 are substantially identical.

Referring to Fig. 1, a storage station 42 is mounted on the frame 26 above the right end of the rails 30 and 34. The storage station 42 includes a storage rack 46 for storing a supply of new reel spools 22, and a pair of spool arms 50 (only one is shown) mounted on the frame 26 below the rack 46 for pivotal movement between a spool receiving position (shown in Fig. 1) and a spool depositing position (not shown). In the spool receiving position, the arms 50 receive a new spool 22 from the storage rack 46. In the spool depositing position, the arms 50 deposit the new spool 22 on the upper surfaces 38 of the rails 30 and 34.

The apparatus 10 also comprises a support belt 54 mounted on the frame 26 for movement along an endless path. The belt 54 is preferably made of a porous, low stretch fabric such as, for example, dryer felt. The belt 54 is supported on rolls 58,62,66,70 and 74, each of which is mounted on the frame 26 for rotation about a respective horizontal axis extending in the cross machine direction. The belt 54 has a generally linear upper run 78 that extends horizontally in the cross machine direction and is angled downwardly in the downstream direction. In other words, the upper run 78 extends at a non-horizontal angle in the machine direction, as generally designated by arrow 20. A drive 82 is operably connected to the roll 70 for moving the belt 54 along its endless path such that the belt upper run moves from right to left in Fig. 1, i. e., in the direction of arrow 79 corresponding to the rotational direction of the wound roll 18, shown by arrow 19, at the point of engagement between the belt 54 and the roll 18. Any suitable drive can be employed.

The roll 74 is preferably a vacuum roll. The vacuum roll 74 resists web floating, i. e., helps keep the web 14 in place. A belt tension assembly 86 controls the tension of the belt 54. The belt tension assembly 86 includes the roll 66, which is preferably a tension roll mounted on tension load cells 90 (shown schematically). The roll 66 is loaded against the belt 54 at a controlled tension using, for example, hydraulic cylinder/piston assemblies 94.

A belt guide assembly 98 maintains the proper position of the belt 54 on the rolls 58,62,66,70 and 74. The belt guide assembly 98 includes the roll 58, which is, at one end (the left end in Fig. 4), fixed against translational movement but pivotable about an axis 100 perpendicular to the roll axis and to the belt upper run 78. The other end of the roll 58 (the right end in Fig. 4 and the end shown in Fig. 1) is translationally or arcuately movable in the direction of the arrow 102 so that the roll 58 can be"skewed"to control the position of the belt 54 on the roll 58. A suitable device, such as a hydraulic cylinder/piston assembly 106, is connected to the free end of the roll 58 for providing the necessary skewing of the roll 58. The belt guide assembly 98 also includes a guide palm 110 for sensinq the position of the belt 54 in the cross machine direction. The guide palm 110 is operably connected to the hydraulic assembly 106 for controlling skewing of the roll 58. This provides a closed loop control of the belt position on the roll 58. Such a belt guide assembly is known in the art and need not be described in greater detail. See, for example, U. S. Patent No.

4,790,908, which is incorporated herein by reference.

The apparatus 10 also comprises (see Figs. 1 and 3) an outer carriage 114 mounted on the outside of the rail 30, an inner carriage 118 mounted on the inside of the rail 30, an inner carriage 124 mounted on the inside of the rail 34, and an outer carriage 128 mounted on the outside of the rail 34. Each of the carriages 114,118,124 and 128 is supported for longitudinal movement parallel to the rails 30 and 34. More particularly, each of the carriages 114, 118,124 and 128 is supported on a respective guide 132 (see Fig. 1) for reciprocal movement along the associated rail. Each of the carriages 114,118, 124 and 128 is selectively operative to engage the end of a reel spool 22, as is known in the art. The carriages operate in pairs, as explained below, with the carriages 114 and 124 cooperating to engage the opposite ends of a spool 22, and with the carriages 118 and 128 cooperating to engage the opposite ends of a different spool 22.

The apparatus 10 further comprises (see Fig. 3) drives 136 and 140, each of which is operable to selectively engage and rotate a reel spool 22 when the reel spool 22 is engaged by a pair of the carriages. More particularly, the drive 136 engages and rotates a spool 22 engaged by the carriages 114 and 124, and the drive 140 engages and rotates a spool 22 engaged by the carriages 118 and 128. Each of the drives 136 and 140 is supported for movement parallel to the rails 30 and 34 and with the engaged reel spool 22.

A suitable drive arrangement is disclosed in U. S. Patent No. 5,370,327, which is incorporated herein by reference.

The apparatus 10 further comprises a positioning device for selectively positioning the carriages 114,118,124 and 128 relative to the rails 30 and 34.

The positioning device preferably includes (see Fig. 3) extendable linkages 144,148,154 and 158 (partially shown) connected between the frame 26 and the carriages 114,118,124 and 128, respectively. In the illustrated construction, the linkages 144,148,154 and 158 are hydraulic cylinder/piston apparatus. Other suitable linkages, such as ball screw and chain and sprocket apparatus, can be employed. The hydraulic apparatus 144,148,154 and 158 are controlled such that, as described above, the carriage 114 is operatively linked with and moves with the carriage 124, and the carriage 118 is operatively linked with and moves with the carriage 128. In this manner, two sets of cooperating pairs of carriages are operative to move two reel spools 22, 22'along the rails 30 and 34. The operation of the hydraulic apparatus 144 and 154 and the associated carriage pair will be described first.

The hydraulic apparatus 144 and 154 are operable to position the carriages 114 and 124 in an initial reeling position (indicated by reference numeral 162 in Figs. 1 and 2) in which the carriages 114 and 124 receive a reel spool 22 deposited on the rails 30 and 34 by the storage station 42, in which the web 14 is thereafter brought into nipping engagement N1 with a fresh reel spool 22 and reeled onto the reel spool 22 engaged by the carriages 114 and 124, and in which the upper run of the belt 54 is in nipping engagement with the web 14 at nip N2 being wound onto the reel spool 22. The paper web 14 travels over the right or upper end of the belt 54 and down the upper run of the belt before being reeled onto the reel spool 22. A paper web tail guiding apparatus 166 (Fig. 1) is mounted on the frame 26 and guides the oncoming paper web tail in the direction of arrow 15 onto the belt 54.

The hydraulic apparatus 144 and 154 thereafter position the carriages _ 114 and 124 downstream of the initial reeling position to control the nip pressure between the belt 54 and the web 14 being wound onto the reel spool 22 during reeling of the wound web roll 18. A controller 170 (shown schematically in Fig. 1) senses the nip pressure between the belt 54 and the wound web roll 18 and controls the hydraulic apparatus 144 and 154 so as to adjust the nip pressure. More particularly, in the illustrated construction, the load cells 90 sense the tension in the belt 54 and thereby sense the nip pressure. Any tension increase due to nip between the roll 18 and the belt 54 is sensed by the load cells 90 and used to control the hydraulic apparatus 144 and 154.

The controller 170 preferably also includes a device 171 for sensing the position of the carriages 114,118,124 and 128, the carriage position being indicative of the diameter of the wound web roll 18. In the illustrated construction, each of the hydraulic apparatus 144,148,154 and 158 (i. e., positioning devices) has a built-in linear variable displacement transducer (LVDT) that indicates roll diameter. The roll diameter can be used to control the drive speed profile/nip profile throughout the buildup of the roll.

The hydraulic apparatus 144 and 154 are also operable to position the carriages 114 and 124 to move the wound web roll 18 out of nipping engagement with the belt 54 (to the left of the belt 54 in Fig. 1) when the desired web roll diameter is reached. The wound web roll 18 is then removed from the carriages 114 and 124 and from the apparatus 10, as is known in the art.

Thus, the wound web roll 18 is moved downstream in the direction of arrow 20 while being horizontally supported by the rails 30 and 34, rotatably driven by the drive 136, and nipped by the belt 54 until the desired web roll diameter is reached.

The hydraulic apparatus 148 and 158 are operable in the same manner as the hydraulic apparatus 144 and 154. After the carriages 114 and 124 move downstream from the initial position, the hydraulic apparatus 148 and 158 position the carriages 118 and 128 in the initial position to receive the next reel spool 22'deposited by the storage station 42. After the preceding reel spool 22 (engaged by the carriages 114 and 124) moves downstream of the belt 54, the arms 50 deposit the next spool 22'on the rails 30 and 34 in engagement with the carriages 118 and 128, and the hydraulic apparatus 148 and 158 move the carriages 118 and 128 in the same manner as described above. The wound web roll 18 is then removed from the carriages 114 and 124, and the hydraulic apparatus 144 and 154 return the carriages 114 and 124 to the initial position to receive the next reel spool 22'.

Various features of the invention are set forth in the following claims.