Packing Apparatus and Method of Forming Stacks of Cut Segments of Web Material

Abstract

A packer forms stacks of segments cut from a web of material. The packer has a shoe that contacts the segment and pushes the segment onto the stack. A follower is operatively connected to the shoe. A drive shaft is operatively connected to a motor. A drive crank is operatively mounted to the drive shaft operatively pivotally connected to the follower. A motion control assembly is configured for synchronized motion with the drive shaft. The motion control assembly has a member operatively connected to the follower. When the drive shaft rotates, the drive crank moves the follower toward and away from a face of the segment and the motion control assembly operates in a manner to move the follower toward and away from a leading edge of the segment.

Description

BACKGROUND

This disclosure is directed to equipment for producing disposable wipes, more particularly, to stacking folded wipes, and more particularly, to a packing apparatus and method for forming stacks of folded wipes. Equipment for producing disposable wipes typically comprises a section for unwinding parent rolls of substrates such as nonwovens or paper into webs of substrate; a section for optionally moistening the webs with a cleaning solution, lotion, or other fluid; a section for folding the webs and interfolding adjacent webs into a continuous ribbon or bolt; a section for cutting the continuous ribbon or bolt into segments or clips of several wipes; a section for combining clips into stacks of a desired number of wipes, this section comprising one or more stackers; and further sections for packaging the stacks of wipes. Within a stacker, to begin the stacking process, a packer transfers segments or clips of cut web material travelling horizontally from the discharge of the cutting section onto a stack below the travel path. The first clip in a stack is transferred onto count fingers. Subsequent clips are transferred onto the previous clip in the stack. After the last clip is transferred onto the stack, the process is repeated with a further set of count fingers.

The clips travelling horizontally from the discharge of the cutting section have a high horizontal velocity and zero vertical velocity. In a short time span, and over a short distance, the clips transition to zero horizontal velocity and a low vertical velocity as the stack is formed. In order to maximize the productivity of the equipment for producing disposable wipes, a packer which makes this velocity transition as smooth as possible, and whose kinematics allow for high cutting and stacking rates, is desired.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a conventional linear packer;

FIG. 2 is a right side view of the conventional linear packer of FIG. 1;

FIG. 3 is a front perspective view of another conventional linear packer;

FIG. 4 is a rear perspective view of the conventional linear packer of FIG. 3;

FIG. 5 is a front view of a conventional orbital packer;

FIG. 6 is a left side cross-sectional view of the conventional linear packer of FIG. 5 taken along section line 6-6 of FIG. 5;

FIG. 7 is a front perspective view of a conventional hybrid orbital-linear packer;

FIG. 8 is a front view of the conventional hybrid orbital-linear packer of FIG. 7;

FIG. 9 is a left side cross-sectional view of the conventional hybrid orbital-linear packer of FIG. 7 taken along section line 9-9 of FIG. 8;

FIG. 10 is a front perspective view of an exemplary packer as set forth herein;

FIG. 11 is a rear perspective view of the packer of FIG. 10;

FIG. 12 is a front perspective view of the packer of FIG. 10 with structural supports removed to provide additional detail of the packer;

FIG. 13 is a rear perspective view of the packer of FIG. 12;

FIG. 14 is a front view of the packer of FIG. 12;

FIG. 15 is a right side cross-sectional view of the packer of FIG. 12 taken along section line A-A of FIG. 14;

FIG. 16 is a right side cross-sectional view of the packer of FIG. 12 taken along section line B-B of FIG. 14;

FIG. 17 is a schematic drawing of a front view of the packer beginning its path of travel to engage a segment of cut web material;

FIGS. 18-26 are schematic drawings front views of the packer on its path of travel to engage and then disengage from the segment of cut web material; and

FIG. 27 is a schematic drawing of a front view of the packer at the end of its path of travel after it has disengaged from the segment of cut web material and travels to a position to engage a successive segment of cut web material.

DETAILED DESCRIPTION

In the description that follows, the terms horizontal, vertical, up, down, left, right, and clock positions are used for ease of description and illustration with reference to the drawings and not in any limiting sense.

FIGS. 1-9 show conventional packers. FIGS. 1 and 2 show a conventional linear packer 30. FIGS. 3 and 4 show another conventional linear packer 32. FIGS. 5 and 6 show a conventional orbital packer 34. FIGS. 7-9 show a conventional hybrid orbital-linear packer 36. Each of these packers has drawbacks that are overcome by the exemplary packer 50 of FIGS. 10-27. The packer of FIGS. 10-27 develops unique motion of the shoe 52 that provides for successful operation of a packer. Without being limited to any specific theory of operation, it is believed that there are at least four primary velocity considerations for enabling a packer to operate as smoothly as possible and transition a clip's 54 velocity from high horizontal velocity and zero vertical velocity to zero horizontal velocity and a low vertical velocity, as the clip is transferred from the discharge of the cutting section onto a stack 56 below the clip's direction of travel 58. First, when the shoe 52 of the packer makes initial contact with the clip 54, the shoe's horizontal component of velocity (i.e., the shoe lateral velocity) should match as closely as possible the horizontal velocity of the clip in the direction of advancement 58. As shown in FIGS. 17-27, the shoe 52 travels in a direction opposition of the direction of advancement of the clip 58, then stops, reverses direction, and travels in the same direction 58 as the clip at a speed that is the same or substantially the same as the advancing clip as the shoe makes contact with the clip. Second, when the clip makes contact with the count fingers below (if the clip is the first in the stack) or with the stack below (if the clip is a clip other than the first in the stack), the shoe's vertical component of velocity (i.e., the shoe transverse velocity) should match as closely as possible the velocity of the count fingers or the clip below in the stack. Third, when the shoe 52 ceases to have contact with the clip 56, the horizontal velocity of the shoe of the packer (the shoe lateral velocity) should be as low as possible, to match as closely as possible the stack's zero horizontal velocity. This velocity matching may minimize slipping between the shoe and the clip, and it may minimize slipping between the clip and the count fingers or the stack. Minimizing slipping reduces the need to rely on a physical barrier to stop the clip's horizontal velocity, as well as ensures reliable placement of the clip. This in turn reduces the potential for damaging the clip, and reduces the potential for producing an uneven stack. Fourth, the motion profile of the packer between the instant the shoe makes contact with the clip and the instant the shoe ceases to have contact with the clip should be free of abrupt changes in acceleration, both for control of the clip and for quiet and reliable operation of the equipment. A packer with these characteristics may be especially advantageous for wipe products with a low coefficient of friction, or for dry wipes products.

Without being limited to any specific theory, it is believed that there are at least four primary motion considerations for enabling the kinematics of a packer to allow for high cutting and stacking rates. First, its motion profile should provide for it to be physically out of the way of subsequent clips. Second, when the shoe of the packer makes initial contact with the clip, the face of the shoe which contacts the clip should be approximately horizontal. Third, when the shoe ceases to have contact with the clip, the face of the shoe which contacts the clip should be approximately horizontal. Small deviations from horizontal are permissible in both instances, especially to the extent that this compromise provides for an increase in another benefit. Fourth, the return path that the shoe travels between when it ceases to have contact with a clip and engages with a subsequent clip should be as short as possible.

Prior art packers 30,32,34,36 as shown in FIGS. 1-9 have drawbacks in terms of how smoothly they transition a clip's velocity from high horizontal velocity and zero vertical velocity to zero horizontal velocity and a low vertical velocity as the stack is formed, and in terms of how high a cutting and stacking rate their kinematics allow. The conventional packers do not meet all of the primary velocity and motion criteria discussed above. The shoe 38,40 of the conventional liner packer 30,32, for instance, as shown in FIGS. 1-4, has only a vertical velocity component, and must be retracted completely above the top of clips being discharged from the cutting section before the next clip can enter the stacking section. The conventional orbital packer 34, for instance, as shown in FIGS. 5-6, provides for a shoe 42 with a degree of velocity matching with the clip, and a motion profile that better provides for the shoe to be physically out of the way of successive clips. However, the length of return path for the shoe is constrained by the orbital motion of the shoe 42. A conventional hybrid orbital-linear packer 36, for instance, as shown in FIGS. 7-9 provides some of the benefits but also some of the drawbacks, of both the conventional linear and conventional orbital packers and fails to completely satisfy all of the design criteria discussed above in that the conventional hybrid linear orbital packer does not satisfy all of the following: (i) the motion profile provides for the shoe to be physically out of the way of successive clips, (ii) the face of the shoe is approximately horizontal when the shoe engages the clip, (iii) the face of the shoe is approximately horizontal when the shoe disengages the clip, (iv) the shoe's travels path from disengagement with one clip and engagement with a subsequent clip is as short as possible, (v) the shoe's horizontal component of velocity matches the horizontal velocity of the clip during initial contact, (vi) when the clip is pushed into the stack, the shoe's vertical component of velocity matches the velocity of stack below the clip, (vii) when the shoe disengages from the clip, the horizontal velocity of the shoe is minimized to match the zero horizontal velocity of the stack; and (viii) the motion profile of the packer between engagement and disengagement of the shoe with the clip is free of abrupt changes in acceleration.

The packer of the present disclosure satisfies all of these criteria. Making reference to FIGS. 10-16, the exemplary packer 50 is adapted and configured from for forming stacks 56 of segments 54 cut from a web of material. As mentioned above, the web material may be folded substrates used for producing disposable wipes. The substrates may be non-woven or paper substrate. The substrate may be moistened with a cleaning solution, lotion, or other fluid. The substrate may be folded into one or more webs and interfolded adjacent webs may form a continuous ribbon or bolt. The packer may be contained in machinery for forming stacks. Within the stacker, the packer may transfer a segment of cut web material (e.g., the clip) from the discharge of the cutting section onto the stack. Depending upon the stage of the processing, the first clip in a stack may be transferred onto count fingers, and subsequent clips may be transferred onto the previous clip in the stack.

The shoe 52 of the packer 50 is adapted and configured to contact the segment 54 and push the segment onto the stack 56 of segments cut from the web of the material, which may be either the count fingers for the first clip or the stack for successive clips. The shoe 52 may adapted and configured to contact the face of the segment 54 and push the segment onto the stack of segments cut from the web of the material. The packer has a support structure 58 for maintaining the spatial arrangement of the elements and components of the packer and the stacker. A follower 60 may be operatively connected to the shoe 52. The follower 60 and shoe 52 may have an adjustable connection 62 to allow fine tuning and setting of a spacing between the shoe and the follower and the stroke of the follower and shoe.

The packer 50 may also include a drive shaft 70 operatively connected to a motor 72. The drive shaft 70 may be rotatable about a drive shaft center axis 74. The drive shaft 70 may be coupled to the motor 72 with a drive belt and pulley system 76. The motor may be a servo motor, variable frequency motor or any other motor allowing for speed control.

A first drive crank 80 may be operatively mounted to the drive shaft 70 and may be offset from the drive shaft center axis 74. As shown in the drawings, the first drive crank 80 is disposed on an axial end of the drive shaft 70 and the pulley 76 is disposed on an intermediate region of the drive shaft. Other arrangements are also possible depending upon the support structure for the packer. The first drive crank 80 may be operatively pivotally connected to the follower 60. The first drive crank 80 is mounted to the drive shaft 70 so as to rotate together with the drive shaft. Thus, in normal operation, the first drive crank rotates 360 degrees when the drive shaft rotates through 360 degrees. In other words, the first drive crank is mounted to the drive shaft so as to complete one revolution with one revolution of the drive shaft.

A second drive crank 82 may be operatively mounted to the drive shaft 70 and may be offset from the drive shaft center axis 74. As shown in the drawing, the second drive crank 82 is mounted to one axial end of the drive shaft and the first drive crank 80 is mounted an opposite end of the drive shaft with the drive pulley 76 between. Other arrangements are also possible depending upon the support structure for the packer. The second drive crank 82 is mounted to the drive shaft so as to rotate together with the drive shaft. Thus, in normal operation, the second drive crank 82 rotates 360 degrees when the drive shaft rotates through 360 degrees. In other words, the second drive crank is mounted to the drive shaft so as to complete one revolution with one revolution of the drive shaft.

Preferably, the drive cranks 80,82 have a set angular arrangement so as to provide coordinated motion of the follower and shoe as will become evident from the discussion that follows. As shown in the drawings and by way of illustration and not in any limiting sense, the first drive crank 80 is mounted to the drive shaft 70 in a first position and the second drive crank 82 is mounted to the drive shaft 70 in a second position where the first position is offset from the second position by an angle of between 150 degrees and 210 degrees. More preferably, the first position is offset from the second position by an angle of about 180 degrees.

The packer also includes a motion control shaft 90. The motion control shaft 90 may have a center axis 92. The motion control shaft center axis 92 may be aligned parallel to and spaced from the drive shaft center axis 74. The motion control shaft 90 may be mounted for rotary motion within the support structure 58 of the packer and may be arranged vertically between the drive shaft 70 and the shoe 52. The motion control shaft 90 may have first and second rocker arms 94,96 extending outward from the motion control shaft. The first rocker arm 94 may be mounted to one end of the motion control shaft 90 and the second rocker arm 96 may be mounted to an opposite end of the motion control shaft. Preferably, the first and second rocker arms 94,96 have a set angular arrangement so as to provide coordinated motion of the follower 60 and the shoe 52 as will become evident from the discussion that follows. As shown in the drawings and by way of illustration and not in any limited sense, the first rocker arm 94 is mounted to the motion control shaft 90 in a first position and the second rocker arm 96 is mounted to the motion control shaft in a second position where the first position is offset from the second position by an angle of between 60 degrees and 120 degrees. More preferably, the first position is offset from the second position by an angle of about 90 degrees.

A motion control drive linkage 100 may extend between the second drive crank 82 and the first rocker arm 94. The motion control drive linkage 10 may have opposite ends. One end of the motion control drive linkage may be pivotally connected to the second drive crank 82. An opposite end of the motion control drive linkage 100 may be pivotally connected to the first rocker arm 94. A motion control strut 102 may extend between the second rocker arm 96 and the follower 60. The motion control strut 102 may have opposite ends. One end of the motion control strut 102 may be pivotally connected to the second rocker arm 96. An opposite end of the motion control strut 102 may be pivotally connected to the follower 60.

The motion control drive linkage 100 causes rotary movement of the first and second rocker arms 94,96. However, the arrangement is such that the rocker arms 94,96 oscillate along an arc segment between angular positions and do not complete revolutions about the motion control center axis 92 during rotation of the drive shaft 70. The first rocker arm 94 may be mounted on the motion control shaft 90 so as to oscillate on an arc segment of between 60 degrees and 120 degrees when the drive shaft rotates one complete revolution. The second rocker arm 96 may be mounted on the motion control shaft 90 so as to oscillate on an arc segment of 60 degrees and 120 degrees when the drive shaft rotates one complete revolution. Making reference to the orientation of the packer shown in

FIG. 14, during normal operation of the packer and one revolution of the drive shaft 70, the first rocker arm 94 may oscillate between the 1 o'clock position and the 4 o'clock position, and the second rocker 96 arm may oscillate between the 4 o'clock position and the 7 o'clock position. So, neither the first rocker arm nor the second rocker arm complete a full revolution about the motion control center axis during rotation of the drive shaft.

In an alternative configuration, the second drive crank 82, the motion control shaft 90 and the rocker arms 94,96, the motion control drive linkage 100, the motion control strut 102 may be eliminated and replaced with a motion control drive mechanism that stabilizes the follower and shoe to satisfy the criteria discussed above. For instance, an independent servo motor may replace the second drive crank 82, the motion control shaft 90, the rocker arms 94,96, and the motion control drive linkage 100, and the independent servo motor may drive a linkage similar to the motion control strut 102 to stabilize the follower and shoe to satisfy the criteria discussed above. A gear train or chain drive with or without linkages may also be used.

Making reference to FIGS. 17-27, when the drive shaft rotates, the first drive crank moves the follower (and thus the shoe) toward and away from a face of the segment and the motion control strut moves the follower (and thus the shoe) toward and away from a leading edge of the segment. Thus, when the drive shaft rotates, the first drive crank moves the follower between engagement and disengagement positions of the shoe with the face of the segment, and the motion control strut moves the follower such that the shoe is parallel with the face of the segment when the shoe is in the engagement position and the shoe is acutely angled with the face of the segment when the shoe is in the disengagement position. In one aspect, the segment cut from the web of material is advanced through the packer in a direction of advancement with a segment advancement velocity, and the shoe of the packer is advanced toward the segment in a direction opposite of the direction of advancement of the segment with a lateral shoe velocity. FIGS. 17-20 generally correspond to this aspect of the motion of the packer. Then the packer motion is arranged so that the shoe moves in a direction transverse to the segment direction of advancement with a transverse shoe velocity. In the drawings, this motion is downward. FIGS. 21-24 generally correspond to this aspect of the motion of the packer. The shoe comes to a zero lateral shoe velocity and reverses direction to match the segment advancement velocity. The shoe also develops a transverse shoe velocity matching the stack downward velocity, the shoe engages the face of the segment and pushes the segment onto a stack of segments cut from the web of the material. FIG. 23 best shows this aspect of the motion of the packer. With the shoe in contact with the face of the segment and the segment pushed onto the stack of segments cut from the web of the material, the lateral shoe velocity and the transverse shoe velocity are at near zero or minimum, and motion of the shoe is temporarily stopped. FIG. 24 best shows this aspect of the motion of the packer. At this point, the shoe is moved away from the segment and to a position where the shoe clears the segment and is ready to begin the process to engage a successive segment. FIGS. 25-27 best show this aspect of the motion of the packer. As best shown in FIGS. 23 and 24, the step of contacting the face of the segment with the shoe and pushing the segment onto the stack of segments cut from the web of the material includes positioning the shoe parallel with the face of the segment. As best shown in FIGS. 25-27, the step of moving the shoe away from segment includes positioning the shoe at an acute angle with the face of the segment.

The lengths of the follower, motion control drive linkage, motion control strut, the first and second drive cranks, and the first and second rocker arms, their respective connection locations, and spatial orientations may be altered as needed from that shown in the drawings to provide for a more optimal combination of smooth velocity transition and kinematics for high speed than is possible with prior packer designs.

Further embodiments can be envisioned by one of ordinary skill in the art after reading this disclosure. In other embodiments, combinations or sub-combinations of the above-disclosed invention can be advantageously made. The example arrangements of components are shown for purposes of illustration and it should be understood that combinations, additions, re-arrangements, and the like are contemplated in alternative embodiments of the present invention. Thus, various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims and that the invention is intended to cover all modifications and equivalents within the scope of the following claims.

Claims

1. A packer for forming stacks of segments cut from a web of material, the packer comprising: a shoe adapted and configured to contact a segment and push the segment onto the stack of segments cut from the web of the material;a follower operatively connected to the shoe;a drive shaft operatively connected to a motor and being rotatable about a drive shaft center axis;a first drive crank operatively mounted to the drive shaft offset from the drive shaft center axis, the first drive crank being operatively pivotally connected to the follower;a second drive crank operatively mounted to the drive shaft offset from the drive shaft center axis;a motion control shaft having a center axis, the motion control shaft center axis being parallel to and spaced from the drive shaft center axis, the motion control shaft having first and second rocker arms extending outward from the shaft;a motion control drive linkage extending between the second drive crank and the first rocker arm of the motion control shaft, the motion control drive linkage being pivotally connected to the second drive crank, the motion control drive linkage being pivotally connected to the first rocker arm of the motion control shaft; anda motion control strut extending between the second rocker arm of the motion control shaft and the follower, the motion control strut being pivotally connected to the second rocker arm of the motion control shaft, the motion control strut being pivotally connected to the follower;wherein when the drive shaft rotates, the first drive crank moves the follower toward and away from a face of the segment and motion control strut moves the follower toward and away from a leading edge of the segment.

2. The packer of claim 1 wherein the drive shaft is driven by a belt.

3. The packer of claim 1 wherein the first drive crank is mounted to one end of the drive shaft and the second drive crank is mounted an opposite end of the drive shaft.

4. The packer of claim 1 wherein the shoe is adjustable relative to the follower.

5. The packer of claim 1 wherein the first rocker arm of the motion control shaft is mounted to one end of the motion control drive shaft and the second rocker arm of the motion control shaft is mounted to an opposite end of the motion control shaft.

6. The packer of claim 1 wherein the motion control shaft is mounted for rotary motion in the packer between the drive shaft and the shoe.

7. The packer of claim 1 wherein the second rocker arm is mounted on the motion control shaft so as to oscillate between 60 degrees and 120 degrees when the drive shaft rotates.

8. The packer of claim 1 wherein the first drive crank is mounted to the drive shaft in a first position and the second drive crank is mounted to the drive shaft in a second position, the first position is offset from the second position by an angle of between 150 degrees and 210 degrees.

9. The packer of claim 1 wherein the first rocker arm is mounted to the motion control shaft in a first position and the second rocker arm is mounted to the motion control shaft in a second position, the first position is offset from the second position by an angle of between 60 degrees and 120 degrees.

10. The packer of claim 1 wherein the first drive crank is mounted to the drive shaft so as to rotate 360 degrees when the drive shaft rotates.

11. The packer of claim 1 wherein the second drive crank is mounted to the drive shaft so as to rotate 360 degrees when the drive shaft rotates.

12. The packer of claim 1 wherein the first rocker arm is mounted on the motion control shaft so as to oscillate between 60 degrees and 120 degrees when the drive shaft rotates.

13. A packer for forming stacks of segments cut from a web of material, the packer comprising: a shoe adapted and configured to contact a face of a segment and push the segment onto the stack of segments cut from the web of the material;a follower operatively connected to the shoe;a drive shaft operatively connected to a motor and being rotatably about a drive shaft center axis;a motion control shaft having a center axis, the motion control shaft center axis being parallel to and spaced from the drive shaft center axis,first and second rocker arms operatively mounted to and extending outward from the motion control shaft;first and second drive cranks operatively mounted to and extending outward from the drive shaft;a motion control drive linkage extending between the second drive crank and the first rocker arm of the motion control shaft, the motion control drive linkage being pivotally connected to the second drive crank, the motion control drive linkage being pivotally connected to the first rocker arm of the motion control shaft; anda motion control strut extending between the second rocker arm of the motion control shaft and the follower, the motion control strut being pivotally connected to the second rocker arm of the motion control shaft, the motion control strut being pivotally connected to the follower;wherein when the drive shaft rotates, the first drive crank moves the follower between engagement and disengagement positions of the shoe with the face of the segment, and the motion control strut moves the follower such that the shoe is parallel with the face of the segment when shoe is in the engagement position and the shoe is acutely angled with the face of the segment when shoe is in the disengagement position.

14. The packer of claim 13 wherein the drive shaft is driven by a belt.

15. The packer of claim 13 wherein the first drive crank is mounted to one end of the drive shaft and the second drive crank is mounted an opposite end of the drive shaft.

16. The packer of claim 13 wherein the shoe is adjustable relative to the follower.

17. The packer of claim 13 wherein the first rocker arm of the motion control shaft is mounted to one end of the motion control drive shaft and the second rocker arm of the motion control shaft is mounted to an opposite end of the motion control shaft.

18. The packer of claim 13 wherein the motion control shaft is mounted for rotary motion in the packer between the drive shaft and the shoe.

19. A packer for forming stacks of segments cut from a web of material, the packer comprising: a shoe adapted and configured to contact a segment and push the segment onto the stack of segments cut from the web of the material;a follower operatively connected to the shoe;a drive shaft operatively connected to a motor and being rotatably about a drive shaft center axis;a drive crank operatively mounted to the drive shaft offset from the drive shaft center axis, the first drive crank being operatively pivotally connected to the follower; anda motion control assembly, the motion control assembly being adapted and configured for synchronized motion with the drive shaft, the motion control assembly having a member operatively connected to the follower;wherein when the drive shaft rotates, the drive crank moves the follower toward and away from a face of the segment and the motion control assembly operates in a manner to move the follower toward and away from a leading edge of the segment.

20. The packer of claim 19 wherein when the drive shaft rotates, the drive crank moves the follower between engagement and disengagement positions of the shoe with the face of the segment, and the motion control assembly operates in a manner to move the follower such that the shoe is parallel with the face of the segment when the shoe is in the engagement position and the shoe is acutely angled with the face of the segment when shoe is in the disengagement position.