Dunnage conversion machine and drive system for feeding sheet material

Abstract

A drive system is configured to feed a sheet. The drive system includes a first roller and a second roller. The first roller has a circumference having a first curved profile. The second roller has a circumference having a second curved profile. The first roller and the second roller are arranged such that when the sheet is not positioned between the first roller and the second roller, the first curved profile of the first roller contacts the second curved profile of the second roller. The first roller and the second roller are further arranged such that when the sheet is positioned between the first roller and the second roller, rotation of at least one of the first roller and the second roller causes the sheet to be fed through the drive system.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of drive systems for sheet material such as paper. More specifically, the present disclosure relates to a drive system including rollers having a circumference with a curved profile and arranged so that the curved profile of one roller contacts the curved profile of the other roller when the sheet material is not located between the two rollers. Background Art

[0002] Machines for producing void filling material from paper are well known in the art. Such machines generally operate by drawing a paper web from a roll or fanfold, manipulating the paper web in a manner that converts the paper into void filling material, and then cutting the converted material into cut sections of the desired length.

[0003] Although such machines are widely used and have been commercially successful, in many applications, improved functionality is still needed. For example, when paper is fed through these machines, the drive system tends to pull the paper in a manner that can cause the paper to tear or rip. In addition, the paper can easily become misaligned while being fed by the drive system. Traditional approaches to reducing these problems can significantly increase the cost of the drive system. It would be advantageous to have a drive system that addresses the problems of paper damage and misalignment while being fed by the drive system without significantly increasing the cost of the drive system. Summary of the Invention

[0004] This summary is provided to introduce a selection of concepts in a simplified form, which are further described below in the detailed description. This summary is neither intended to identify key features of the claimed subject matter nor to be used as an aid in determining the scope of the claimed subject matter.

[0005] In a first embodiment, a dunnage conversion machine includes a sheet material source and a conversion system. The sheet material is in a substantially flat configuration in the sheet material source. The conversion system is configured to convert the sheet material from the substantially flat configuration to a non-flat configuration. The conversion system includes a drive system configured to draw the sheet material from the source and through the conversion system. The drive system includes a first roller and a second roller, wherein the circumference of the first roller has a first curved profile and the circumference of the second roller has a second curved profile. The first roller and the second roller are arranged such that when the sheet material is not between the first roller and the second roller, the first curved profile of the first roller contacts the second curved profile of the second roller. When the sheet material is between the first roller and the second roller, the drive system is configured to feed the sheet material through the drive system by rotating at least one of the first roller and the second roller.

[0006] In a second embodiment, the first roller and the second roller of the first embodiment are molded elastomeric wheels.

[0007] In a third embodiment, the molded elastomeric wheel of the second embodiment is a molded polyurethane wheel.

[0008] In a fourth embodiment, the dunnage conversion machine of the first embodiment further includes a biasing mechanism configured to bias the first roller toward the second roller.

[0009] In a fifth embodiment, the biasing mechanism of the fourth embodiment includes a compression spring coupled between the shaft of the first roller and the shaft of the second roller.

[0010] In a sixth embodiment, the shaft of the first roller of the fifth embodiment is movable relative to the shaft of the second roller such that the shafts of the first and second rollers remain substantially parallel to each other.

[0011] In the seventh embodiment, the shaft of the first roller of the sixth embodiment is movable relative to the shaft of the second roller within a range that allows the multilayer sheet to pass between the first roller and the second roller.

[0012] In an eighth embodiment, the shaft of the second roller of any one of the fifth to seventh embodiments is coupled to a motor, and the motor is configured to drive rotation of the shaft of the second roller and rotation of the second roller.

[0013] In a ninth embodiment, the first roller of the eighth embodiment is capable of spinning freely, and the force applied by the biasing mechanism to the shaft of the first roller causes the first roller to contact one of the sheet or the second roller, so that when the rotation of the second roller is driven by the motor, the first roller and the second roller rotate in opposite directions.

[0014] In the tenth embodiment, the biasing mechanism of any one of the fourth to ninth embodiments is capable of disengaging when the sheet is initially fed between the first roller and the second roller.

[0015] In the eleventh embodiment, when the sheet is not located between the first roller and the second roller of any of the preceding embodiments, the point on the first roller that contacts the second curved profile of the second roller is tangent to the two-dimensional tangent plane, and the point on the second roller that contacts the first curved profile of the first roller is tangent to the two-dimensional tangent plane.

[0016] In the twelfth embodiment, the two-dimensional tangent plane of the eleventh embodiment is substantially perpendicular to the axis plane, and the axis plane passes through the axis of the first roller and the axis of the second roller.

[0017] In a thirteenth embodiment, the sheet material of any of the preceding embodiments is kraft paper.

[0018] In a fourteenth embodiment, in the sheet material source of the thirteenth embodiment, the kraft paper is stacked in a fan-shaped manner or in a roll.

[0019] In a fifteenth embodiment, a drive system for feeding a sheet includes a first roller and a second roller. The first roller has a circumference having a first curved profile, and the second roller has a circumference having a second curved profile. The first roller and the second roller are arranged so that (i) when the sheet is not between the first roller and the second roller, the first curved profile of the first roller contacts the second curved profile of the second roller, and (2) when the sheet is between the first roller and the second roller, rotation of at least one of the first roller and the second roller causes the sheet to be fed through the drive system.

[0020] In a sixteenth embodiment, the first roller and the second roller of the fifteenth embodiment are aligned so that when the sheet is not located between the first roller and the second roller, the point on the first roller that contacts the second curved profile of the second roller is on the maximum circumference of the first roller, and the point on the second roller that contacts the first curved profile of the first roller is on the maximum circumference of the second roller.

[0021] In a seventeenth embodiment, the first roller and the second roller of any one of the fifteenth or sixteenth embodiments are offset so that when the sheet is not located between the first roller and the second roller, the point on the first roller that contacts the second curved profile of the second roller is not on the maximum circumference of the first roller, and the point on the second roller that contacts the first curved profile of the first roller is not on the maximum circumference of the second roller.

[0022] In an eighteenth embodiment, the first roller of the seventeenth embodiment is on a first shaft, and the second roller is on a second shaft. The drive system further includes a third roller on the second shaft, wherein the circumference of the third roller has a third curved profile. The first and third rollers are arranged such that when a sheet is not positioned between the first and third rollers, the first curved profile of the first roller contacts the third curved profile of the third roller.

[0023] In the nineteenth embodiment, when the sheet is not located between the first roller and the second and third rollers in the eighteenth embodiment, the second and third curved profiles contact the first curved profile on opposite sides of the maximum circumference of the first roller.

[0024] In a twentieth embodiment, the first shaft and the second shaft of either the eighteenth or nineteenth embodiment are substantially parallel to each other.

[0025] In a twenty-first embodiment, the drive system of any one of the fifteenth to twentieth embodiments further includes a biasing mechanism configured to bias the first roller toward the second roller.

[0026] In a twenty-second embodiment, the first roller and the second roller of any one of the fifteenth to twenty-first embodiments are molded elastomeric wheels. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The foregoing aspects and many of the attendant advantages of the disclosed subject matter will become more readily appreciated as they become better understood upon reference to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0028] Figure 1A and 1B Depicted are embodiments of a dunnage conversion system including a sheet material source and a conversion system according to embodiments discussed herein;

[0029] Figure 1C depicts an embodiment of a conversion system that may be included in a dunnage conversion machine according to embodiments discussed herein;

[0030] Figure 2A and 2B A front view and a side view of a drive system in a conventional paper dunnage machine are respectively depicted;

[0031] Figure 3A and 3B A front view and a side view of another drive system in a conventional paper dunnage machine are respectively depicted;

[0032] Figure 4A and 4B depicts front and side views, respectively, of an embodiment of a drive system having substantially aligned rollers according to embodiments discussed herein;

[0033] Figure 5A and 5B According to the embodiments discussed in this article, Figure 4A and 4B Side and front cross-sectional views of one of the rollers of the drive system shown in ;

[0034] Figure 6A and 6B Depicts the following examples according to the present invention: Figure 5A and 5B An embodiment of a roller that is a variation of the roller shown in ;

[0035] Figure 7A and 7B depicts a front view and a partial perspective view, respectively, of an embodiment of a drive system having rollers offset from one another according to embodiments discussed herein;

[0036] Figure 8A and 8B Depicts a front view of an embodiment of a drive system according to embodiments discussed herein, the drive system being Figure 7A and 7B A variation of the drive system shown in ;

[0037] Figure 9A and 9Bdepicts front and side views, respectively, of an embodiment of a conversion system that may be used in a dunnage conversion machine according to embodiments discussed herein;

[0038] Figure 10A and 10B depicts a front view and a side view, respectively, of another embodiment of a conversion system that may be used in a dunnage conversion machine according to embodiments discussed herein;

[0039] Figure 11A and 11B depicts front and side views, respectively, of yet another embodiment of a conversion system that may be used in a dunnage conversion machine according to embodiments discussed herein; and

[0040] Figure 12 Depicted is a side view of an embodiment of a conversion system 600 having a biasing mechanism arrangement that can be used in any of the embodiments of the conversion systems disclosed herein to bias one roller toward another roller, according to embodiments discussed herein. DETAILED DESCRIPTION

[0041] This disclosure describes embodiments of a drive system for sheet material. In some embodiments, the drive system includes rollers having a circumference with a curved profile. The rollers are arranged so that when a sheet material is not positioned between the rollers, the curved profile of one roller contacts the curved profile of the other roller. The drive system can be used to feed sheet material, such as paper, through a dunnage conversion machine.

[0042] Figure 1A Depicted in FIGURE is an embodiment of a dunnage conversion system 2. The dunnage conversion system 2 includes a source 4 of sheet material 6. In the embodiment shown, the source 4 is a roll of sheet material 6. In some embodiments, the sheet material 6 is a paper-based material, such as kraft paper. In the source 4, the sheet material 6 is in a substantially flat configuration. For example, the roll may hold a single layer of kraft paper that is flat across the width of the roll. In another example, the roll may hold multiple layers of sheet material, each layer being flat across the width of the roll. In another example, a single sheet of paper may be folded longitudinally so that the paper is flat on both sides of the fold, and the paper rolled so that the longitudinal fold is on one side of the roll and the two longitudinal edges are on the other side of the roll. Many other variations of the source 4 of sheet material 6 in roll form are possible.

[0043] The dunnage conversion system 2 includes a dunnage conversion machine 8. The dunnage conversion machine 8 is configured to convert sheet material from a substantially flat configuration of a sheet material 6 into a non-flat configuration of a mat 10. In some embodiments, the sheet material 6 is kraft paper, and the dunnage conversion machine 8 is configured to manipulate the kraft paper in a manner that converts the kraft paper into a mat 10 that can be used as a low-density void-filling material. In some embodiments, the dunnage conversion machine 8 includes a cutting mechanism to cut the mat 10 at intervals to form individual mats. In some embodiments, the dunnage conversion machine 8 also includes a drive system configured to feed (e.g., pull) the sheet material 6 from the source 4 into the dunnage conversion machine 8 and feed the sheet material 6 through the dunnage conversion machine 8 while the sheet material 6 is converted into the mat 10.

[0044] Figure 1B Depicted in FIGURE is an embodiment of a dunnage conversion system 12. The dunnage conversion system 12 includes a source 14 of sheet material 16. In the embodiment shown, the source 14 is a fan-fold stack of sheet material 16. In some embodiments, the sheet material 16 is a paper-based material, such as kraft paper. In the source 14, the sheet material 16 is in a substantially flat configuration. For example, the fan-fold stack may hold a single layer of kraft paper that is flat between the transverse folds and across the width of the fan-fold stack. In another example, the fan-fold stack may hold multiple layers of sheet material, each layer of which is flat between the transverse folds and across the width of the fan-fold stack. Many other variations of the source 4 of sheet material 6 in the form of a fan-fold stack are possible. The dunnage conversion machine 8 in the dunnage conversion system 12 is the same as the dunnage conversion machine 8 in the dunnage conversion system 2 and is capable of converting the sheet material 16 into a mat 10.

[0045] Figure 1C , is an embodiment of a conversion system 20 that can be included in any of the dunnage conversion machines described herein, including dunnage conversion machine 8. Conversion system 20 includes a hopper device 22 and a drive system 24. Funnel device 22 is configured to receive a sheet 26 and begin deforming sheet 26. In the illustrated embodiment, sheet 26 is in a substantially flat configuration upstream of hopper device 22. In some embodiments, hopper device 22 can cause sheet 26 to curl, fold, or otherwise deform before sheet 26 reaches hopper device 22. Drive system 24 is configured to draw sheet 26 from a source (e.g., a roll or fan-fold stack) and through conversion system 20. In some embodiments, drive system 24 is configured to further deform sheet 26 as it passes through drive system 24. After sheet 26 passes through conversion system 20, sheet 26 exists in conversion system 20 in a non-flat configuration. In the illustrated embodiment, sheet 26 exists in conversion system 20 in a non-flat configuration in the form of a mat 28.

[0046] Existing paper dunnage machines include a drive system. Figure 2A and 2BA front view and a side view of an embodiment of a drive system 30 are depicted, respectively. The drive system 30 is a dual cylindrical roller type drive system. The drive system includes cylindrical rollers 32 and 34. Cylindrical roller 32 is on a shaft 36, and cylindrical roller 34 is on a shaft 38. Shafts 36 and 38 extend axially in the x-direction and are axially parallel to each other. Cylindrical rollers 32 and 34 are each tangential to an xz plane 40 in a single direction. In the embodiment shown, cylindrical rollers 32 and 34 extend axially in the z-direction (e.g., Figure 2B visible) but not in the x direction (as Figure 2A The sheet passes between the cylindrical rollers 32 and 34. At least one of the cylindrical rollers 32 and 34 is driven so that the cylindrical rollers 32 and 34 rotate in opposite directions to feed the sheet.

[0047] Figure 3A and 3B A front view and a side view, respectively, of an embodiment of the drive system 50 are depicted. The drive system 50 is a dual spur gear roller type drive system. The drive system includes spur gears 52 and 54. The spur gear 52 is on a shaft 56 and the spur gear 54 is on a shaft 58. The shafts 56 and 58 extend axially in the x-direction and are axially parallel to each other. The teeth of the spur gears 52 and 54 contact each other at a pinch point 62. At the pinch point 62, the teeth of the spur gears 52 and 54 are both tangential to the xz' plane 60 in a single direction. In the embodiment shown, the teeth of the spur gears 52 and 54 at the pinch point 60 are tangential to the xz' plane 60 in a single direction. Figure 3B The sheet passes between the spur gears 52 and 54. At least one of the spur gears 52 and 54 is driven so that the spur gears 52 and 54 rotate in opposite directions to feed the sheet.

[0048] Existing paper shimming machines are widely used and have achieved commercial success. However, the drive systems in existing paper shimming machines have drawbacks. For example, the drive systems tend to pull the paper in a manner that can cause it to rip or tear. Furthermore, the paper can easily become misaligned when fed by the drive systems. For example, in drive system 30, the paper is typically fed between cylindrical rollers 32 and 34 in the negative z-direction. However, if the paper is fed uniformly at a slight angle relative to the negative z-direction, the paper will tend to shift to one side of cylindrical rollers 32 and 34 during feeding. In the illustrated embodiment, the paper tends to shift to one side of cylindrical rollers 32 and 34 in the x-direction, or negative x-direction. Similarly, in drive system 50, the paper is typically fed between spur gears 52 and 54 in the negative z-direction. However, if the paper is fed uniformly at a slight angle relative to the negative z-direction, the paper will tend to shift to one side of spur gears 52 and 54 during feeding. In the embodiment shown, the paper tends to shift in the x-direction, or negative x-direction, to one side of the spur gears 52 and 54. As the drive system continues to operate, this misalignment of the paper from one side of the drive system can cause the paper to tear or rip.

[0049] The traditional approach to reducing these drive system problems can greatly increase the cost of the drive system. For example, in the drive system 30, non-standard rollers can be developed to reduce the possibility of misalignment. However, non-standard rollers may be very expensive, causing the drive system 30 and therefore the paper padding machine to be more expensive. In another example, in the drive system 50, gears other than spur gears (for example, helical gears, etc.) are used to attempt to control the alignment of the paper. However, such gears may be very expensive and may produce other difficulties, such as axial thrust and the need to add bearings to the system. A drive system that solves the problem of damage and misalignment of paper when the paper is fed by the drive system without increasing the cost of the drive system would be advantageous.

[0050] Described herein are embodiments of a drive system that may be included in a conversion system for a padding conversion machine. In some embodiments, the drive system is configured to extract sheet material from a source of sheet material in the padding conversion machine. In some embodiments, the sheet material is paper, such as kraft paper. In some embodiments, the drive system includes at least two rollers having a circumference with a curved profile. In some instances, the rollers are molded elastomeric wheels, such as molded polyurethane wheels, which are readily available and relatively inexpensive. When the sheet material is not between the rollers, the curved profiles of the rollers contact each other such that the rollers are two-dimensionally tangent to a plane passing between the rollers. When the sheet material is between the rollers, the drive system is configured to feed the sheet material through the drive system by rotating at least one of the rollers.

[0051] Figure 4A and 4BA front view and a side view of an embodiment of drive system 100 are depicted, respectively. Drive system 100 includes roller 110 and roller 130. Each of rollers 110 and 130 is in the form of a wheel. Roller 110 includes a hub 112, a contact material 114, and a coupler 116. Similarly, roller 130 includes a hub 132, a contact material 134, and a coupler 136. In some embodiments, hubs 112 and 132 are formed from a rigid material, such as metal. In some embodiments, contact materials 114 and 134 are made from an elastic material, such as an elastomer. For example, contact materials 114 and 134 can be made from urethane or polyurethane. In some embodiments, contact materials 114 and 134 are made from an elastomer having a durometer hardness in the range of about 72A to about 98A when measured according to ASTM D2240. Couplers 116 and 136 are configured to couple rollers 110 and 130 to a shaft. In the illustrated embodiment, roller 110 is on shaft 118, and roller 130 is on shaft 138. In some embodiments, couplings 116 and 136 are bearings configured to reduce friction between rollers 110 and 130 and the shafts on which they rotate.

[0052] like Figure 4A As can be seen in FIG, the circumference of roller 110 has a curved profile 120, and the circumference of roller 130 has a curved profile 140. In the embodiment shown, the curved profile 120 of roller 110 and the curved profile 140 of roller 130 have substantially similar shapes. When the sheet is not placed between rollers 110 and 130, as shown in FIG. Figure 4A and 4B In the case of the roller 110, the curved profile 120 contacts the curved profile 140 of the roller 130. If a sheet such as paper is inserted between the rollers 110 and 130, the drive system 100 is configured to feed the sheet by rotating at least one of the rollers 110 and 130.

[0053] The shafts 118 and 138 extend axially in the x-direction and are axially parallel to each other. The rollers 110 and 130 are each tangential to the two-dimensional tangent plane 102 in two directions. In the embodiment shown, the two-dimensional tangent plane 102 is the xz plane, and the rollers 110 and 130 are tangential to the two-dimensional tangent plane 102 in the x-direction (e.g., Figure 4A in the z direction (as can be seen in Figure 4B102). In some embodiments, the contact between the curved profiles 120 and 140 of rollers 110 and 130 is referred to as "tangent-to-tangent contact" (because they are tangent in two directions), or "point-to-tangent contact" (because the point on curved profile 120 that contacts curved profile 140 and the point on curved profile 140 that contacts curved profile 120 are each tangent to the two-dimensional tangent plane 102). When the sheet is positioned between rollers 110 and 130, drive system 100 is configured to feed the sheet through drive system 100 by rotating at least one of rollers 110 and 130. When the sheet is fed between rollers 110 and 130 in the negative z-direction, the tangent-to-tangent contact of the curved profiles 120 and 140 of rollers 110 and 130 allows the sheet to be translated in both the x-direction and the negative x-direction as the sheet is fed, regardless of the angle at which the sheet is fed into rollers 110 and 130. In some cases, drive system 100 has a tendency to center the sheet in the x-direction as the sheet is fed between rollers 110 and 130 in the negative z-direction.

[0054] In the illustrated embodiment, the shaft 118 and the shaft 138 are substantially parallel to each other. The shaft 118 and the shaft 138 are also substantially parallel to the two-dimensional tangent plane 102. Figure 4B An axial plane 104 (e.g., an xy plane) is shown passing through the shafts 118 and 138 of the rollers 110 and 130. In the embodiment shown, the two-dimensional tangent plane 102 is substantially perpendicular to the axial plane 104. In the embodiment shown, the rollers 110 and 130 are aligned in the x-direction. Figure 4A As can be seen in FIG, the alignment of rollers 110 and 130 results in the point on roller 110 that contacts curved profile 140 of roller 130 being on the maximum circumference of roller 110, and the point on roller 130 that contacts curved profile 120 of roller 110 being on the maximum circumference of roller 130. In other embodiments, the rollers may be offset, examples of which are provided below.

[0055] In some embodiments, rollers 110 and 130 are molded elastomeric wheels, such as molded polyurethane wheels. Molded elastomeric wheels are readily available as off-the-shelf parts because they are used in many products, such as inline skates, scooters, roller conveyors, casters, and the like. Molded elastomeric wheels are not only readily available, but are also relatively inexpensive compared to other conventional rollers (such as cylindrical rollers, spur gears, and the like). In addition, molded elastomeric wheels are designed to withstand a variety of harsh physical environments without suffering fatal deformation. This allows the molded elastomeric wheels to be used for a long time without requiring replacement.

[0056] Figure 5A and 5B In FIG, a side cross-sectional view and a front cross-sectional view of a roller 110 in the form of an elastomeric wheel are depicted respectively. In some embodiments, the roller 130 may have Figure 5BThe cross section of the roller 110 shown in FIG is similar to the cross section of FIG. Figure 5B As can be seen in FIG, the entire circumference of roller 110 is curved. In other words, when viewing Figure 5B , the curved profile 120 of the roller 110 extends from the left side of the roller 110 to the right side of the roller 110 .

[0057] Figure 6A and 6B Embodiments of roller 150 and roller 170 are depicted, respectively. Roller 150 includes a hub 152, a contact material 154, and a coupler 156. Similarly, roller 170 includes a hub 172, a contact material 174, and a coupler 176. In some embodiments, hubs 152 and 172 are formed from a rigid material, such as metal. In some embodiments, contact materials 154 and 174 are made from a resilient material, such as an elastomer. For example, contact materials 154 and 174 may be made from urethane or polyurethane. In some embodiments, contact materials 154 and 174 are made from an elastomer having a durometer hardness in the range of about 72A to about 98A when measured according to ASTM D2240. Couplers 156 and 176 are configured to couple rollers 150 and 170 to a shaft. In some embodiments, couplers 156 and 176 are bearings configured to reduce friction between rollers 150 and 170 and the shaft on which rollers 150 and 170 rotate.

[0058] The circumference of roller 150 has a curved profile 160. Similar to roller 110, the entire circumference of roller 150 is curved. Figure 6A , the curved profile 160 of roller 150 extends from the left side of roller 150 to the right side of roller 150. The curved profile 160 of roller 150 has a different curvature than the curved profile 120 of roller 110. Specifically, the curved profile 160 of roller 150 is steeper than the curved profile 120 of roller 110. The curved profile 160 of roller 150 also extends downwardly closer to hub 152 than the curved profile 120 of roller 110 extends downwardly to hub 112. The circumference of roller 170 has a curved profile 180. Unlike roller 110, the circumference of roller 170 is not completely curved. Specifically, the circumference of roller 170 includes flat portions 182 between portions of the curved profile 180. When viewing Figure 6B 180 , a portion of the curved profile 180 of roller 170 extends from the left side of roller 170 to the flat portion 182, and another portion of the curved profile 180 of roller 170 extends from the flat portion 182 to the right side of roller 170. In other embodiments, rollers having circumferences with curved profiles, such as variations of rollers 110, 130, 150, and 170, are possible and will be apparent to those skilled in the art.

[0059] Figure 7A and 7BA front view and a partial perspective view of an embodiment of a drive system 200 having rollers offset from one another are depicted, respectively. Drive system 200 includes roller 210 and roller 230. Each of rollers 210 and 230 is in the form of a wheel. Roller 210 includes contact material 214, and roller 230 includes contact material 234. In some embodiments, contact materials 214 and 234 are made of an elastic material, such as an elastomer. For example, contact materials 214 and 234 may be made of urethane or polyurethane. In some embodiments, contact materials 214 and 234 are made of an elastomer having a durometer hardness ranging from about 72A to about 98A when measured according to ASTM D2240. In the illustrated embodiment, roller 210 is mounted on shaft 222, and roller 230 is mounted on shaft 242. In some embodiments, rollers 210 and 230 are molded elastomeric wheels, such as molded polyurethane wheels. Molded elastomeric wheels are readily available as off-the-shelf parts, are relatively inexpensive, and generally provide long service life without failure.

[0060] like Figure 7A As can be seen in FIG, the circumference of roller 210 has a curved profile 220, and the circumference of roller 230 has a curved profile 240. In the embodiment shown, the curved profile 220 of roller 210 and the curved profile 240 of roller 230 have substantially similar shapes. When the sheet is not placed between rollers 210 and 230, as shown in FIG. Figure 7A and 7B In the case of the roller 210, the curved profile 220 contacts the curved profile 240 of the roller 230. If a sheet such as paper is inserted between the rollers 210 and 230, the drive system 200 is configured to feed the sheet by rotating at least one of the rollers 210 and 230.

[0061] The shafts 222 and 242 extend axially in the x-direction and are axially parallel to each other. The rollers 210 and 230 are each tangential to the two-dimensional tangent plane 202 in two directions. In the embodiment shown, the rollers 210 and 230 are offset so that the two-dimensional tangent plane 202 is the x'z plane. The rollers 210 and 230 are tangential to the two-dimensional tangent plane 202 in the x' direction (e.g., Figure 7A in the z direction (as can be seen in Figure 7Btangent to the two-dimensional tangent plane 202 (as seen in FIG. 2 ). In some embodiments, the contact between the curved profiles 220 and 240 of the rollers 210 and 230 is referred to as "tangent-to-tangent contact" (because they are tangent in two directions), or "point-to-tangent contact" (because the point on the curved profile 220 that contacts the curved profile 240 and the point on the curved profile 240 that contacts the curved profile 220 are each tangent to the two-dimensional tangent plane 202). When the sheet is positioned between the rollers 210 and 230, the drive system 200 is configured to feed the sheet through the drive system 200 by rotating at least one of the rollers 210 and 230. When the sheet is fed between the rollers 210 and 230 in the negative z-direction, the tangent-to-tangent contact of the curved profiles 220 and 240 of the rollers 210 and 230 allows the sheet to be translated in both the x' direction and the negative x' direction as the sheet is fed, regardless of the angle at which the sheet is fed into the rollers 210 and 230. In some cases, drive system 200 has a tendency to center the sheet in the x' direction as the sheet is fed between rollers 210 and 230 in the negative z-direction.

[0062] In the embodiment shown, the shaft 222 and the shaft 242 are substantially parallel to each other. In the embodiment shown, the two-dimensional tangent plane 202 is substantially perpendicular to the axial plane (e.g., the xy plane) passing through the shafts 222 and 242 of the rollers 210 and 230. In the embodiment shown, the rollers 210 and 230 are offset in the x-direction. Figure 7A As can be seen in FIG, the offset of rollers 210 and 230 results in the point on roller 210 contacting curved profile 240 of roller 230 not being on the maximum circumference of roller 210 and the point on roller 230 contacting curved profile 220 of roller 210 not being on the maximum circumference of roller 230.

[0063] While some embodiments of the drive systems described herein have two rollers, the drive system may have more than two rollers. Figure 8A Depicted in FIG is a front view of an embodiment of a drive system 200′ that is a variation of drive system 200. Similar to drive system 200, drive system 200′ includes rollers 210 and 230 located on shafts 222 and 242, respectively. Drive system 200′ also includes roller 250 on shaft 242. The circumference of roller 250 includes a curved profile 252. When a sheet is not placed between rollers 210, 230, and 250, as shown in FIG. Figure 8A In the case of the roller 250, the curved profile 252 contacts the curved profile 220 of the roller 210. The rollers 210 and 250 are each tangential to the two-dimensional tangent plane 204 in two directions. If a sheet such as paper is inserted between the rollers 210, 230 and 250, the drive system 200 is configured to feed the sheet by rotating at least one of the rollers 210, 230 and 250. When no sheet is placed between the rollers 210, 230 and 250, as shown in FIG. Figure 8AIn the case of FIG. 2 , the curved profiles 240 and 252 contact the curved profile 220 on opposite sides of the maximum circumference of the roller 210 .

[0064] Figure 8B Depicted in FIG is a front view of an embodiment of a drive system 200″ that is a variation of drive system 200′. Similar to drive system 200′, drive system 200″ includes roller 210 on shaft 222, and rollers 230 and 250 are each located on shaft 242. Drive system 200″ also includes roller 260 on shaft 222 and roller 270 on shaft 242. The circumference of roller 260 includes a curved profile 262, and the circumference of roller 270 includes a curved profile 272. When a sheet is not placed between rollers 210, 230, 250, 260, and 270, as shown in FIG. Figure 8B In the embodiment shown in FIG. 2 , curved profile 262 of roller 260 contacts curved profile 252 of roller 250, and curved profile 272 of roller 270 contacts curved profile 262 of roller 260. Rollers 250 and 260 are each tangential to two-dimensional tangent plane 206 in two directions. Rollers 260 and 270 are each tangential to two-dimensional tangent plane 208 in two directions. If a sheet of material, such as paper, is inserted between rollers 210, 230, 250, 260, and 270, drive system 200 is configured to feed the sheet by rotating at least one of rollers 210, 230, 250, 260, and 270. It will be apparent to those skilled in the art that any number of rollers may be used in the drive system.

[0065] Figure 9A and 9B A front view and a side view, respectively, of an embodiment of a conversion system 300 that can be used in a dunnage conversion machine are depicted. Conversion system 300 includes a frame 302 configured to hold components of a drive system 304. Drive system 304 is configured to draw sheet material from a source of sheet material in the dunnage conversion machine. In some embodiments, the sheet material is paper, such as kraft paper. In the illustrated embodiment, an example of a profile 306 of the sheet material is depicted between roller 310 and roller 320. In some embodiments, rollers 310 and 320 are molded elastomeric wheels, such as molded polyurethane wheels. Roller 310 has a circumference with a curved profile 312, and roller 320 has a circumference with a curved profile 322. When the sheet material is not positioned between rollers 310 and 320, curved profile 312 of roller 310 contacts curved profile 322 of roller 320. When the sheet material is positioned between rollers 310 and 320, drive system 304 is configured to feed the sheet material through drive system 304 by rotating at least one of rollers 310 and 320. In the embodiment shown, the profile 306 of the sheet is arranged so that the multi-layered sheet passes between rollers 310 and 320 .

[0066] In the illustrated embodiment, drive system 304 includes a shaft 314 for roller 310 and a shaft 324 for roller 320. In the illustrated embodiment, shafts 314 and 324 are substantially parallel to each other. In some embodiments, roller 310 is configured to rotate freely relative to shaft 314, while roller 320 cannot rotate relative to shaft 324. Thus, roller 320 can be driven by rotation of shaft 324, and roller 310 can rotate in the opposite direction relative to roller 320 when driven. In the illustrated embodiment, shaft 314 includes a biasing mechanism 316 positioned between one side of roller 310 and frame 302. In some cases, biasing mechanism 316 is configured to bias roller 310 to a position substantially centered between the sides of frame 302. In the illustrated embodiment, shaft 324 includes a biasing mechanism 326 positioned between one side of roller 320 and frame 302. In some cases, biasing mechanism 326 is configured to bias roller 320 to a position substantially centered between the sides of frame 302. In the illustrated embodiment, rollers 310 and 320 are aligned so that when a sheet is not positioned between rollers 310 and 320, the point on roller 310 that contacts the curved profile 322 of roller 320 is on the maximum circumference of roller 310, and the point on roller 320 that contacts the curved profile 312 of roller 310 is on the maximum circumference of roller 320.

[0067] The conversion system 300 also includes a biasing mechanism 330 configured to bias the roller 310 toward the roller 320. In the illustrated embodiment, the biasing mechanism 330 is a compression spring that extends between the shaft 314 of the roller 310 and a post 332 fixedly coupled to the frame 302. Figure 9A and 9B In the illustrated embodiment, the shaft 324 of the roller 320 is not capable of translational movement relative to the frame 302. Thus, in the illustrated embodiment, the biasing mechanism 330 is coupled between the shaft 314 of the roller 310 and the shaft 324 of the roller 320 when the biasing mechanism 330 extends between the shaft 314 of the roller 310 and the post 332. The shaft 314 of the roller 310 passes through a slot 308 in the frame 302 that permits translational movement of the shaft 314. The slot 308 permits the roller 310 to be biased toward the roller 320 when no sheet is positioned between the rollers 310 and 320. The slot 308 also permits the roller 310 to be moved away from the roller 320 when a sheet passes between the rollers 310 and 320, particularly when a multi-layered sheet and / or a deformed (e.g., folded or wrinkled) sheet passes between the rollers 310 and 320. In some embodiments, the biasing mechanism 330 is configured to disengage when the sheet is initially fed between the rollers 310 and 320. For example, the hook of the compression spring can be removed from the shaft 314 so that the user can manually lift the roller 310 while the user manually feeds the initial portion of the sheet through the rollers 310 and 320.

[0068] The conversion system 300 also includes a motor 334. In some embodiments, the motor can be an electric motor, a heat engine (e.g., an internal combustion engine), a chemical motor, a pneumatic motor, a hydraulic motor, or any other type of motor or engine. In the illustrated embodiment, the motor 334 is fixedly coupled to the frame 302. The motor 334 is configured to engage the shaft 324 and, when the motor 334 is operated, rotate the shaft 324. In some embodiments, the roller 320 cannot rotate relative to the shaft 324, so that the roller 320 and the shaft 324 rotate in response to the motor 334 driving the shaft 324. In some embodiments, the motor 334 is communicatively coupled to a computing device (e.g., a controller) configured to control the operation of the motor 334. For example, the computing device can control one or more of when the motor 334 operates, the speed at which the motor 334 operates, the torque generated by the motor 334, etc.

[0069] In some embodiments, the conversion system 300 may be part of a dunnage conversion machine that also includes a sheet material source. The sheet material source may be a roll of sheet material, a fan-shaped stack of sheet material, or any other source. The sheet material is in a substantially flat configuration in the source. The conversion system 300 is configured to feed the sheet material from the source through the drive system 304. The conversion system 300 is also configured to convert the sheet material from a substantially flat configuration to a non-flat configuration. In some embodiments, the drive system 304 alone is capable of converting the sheet material from a substantially flat configuration to a non-flat configuration. In some embodiments, the conversion system 300 includes other components, such as a hopper device or other tortuous path component, that is configured to deform the sheet material from a substantially flat configuration as the sheet material is fed from the source to the drive system 304. In embodiments where the rollers 310 and 320 are elastomeric wheels, the friction between the sheet material and the elastomeric material of the rollers 310 and 320 can increase the efficiency of the drive system 304 in feeding the sheet material through the conversion system 300.

[0070] Figure 10A and 10BA front view and a side view, respectively, of another embodiment of a conversion system 400 that can be used in a dunnage conversion machine are depicted. Conversion system 400 includes a frame 402 configured to hold components of a drive system 404. Drive system 404 is configured to draw sheet material from a source of sheet material in the dunnage conversion machine. In some embodiments, the sheet material is paper, such as kraft paper. In the illustrated embodiment, an example of a profile 406 of the sheet material is depicted between roller 410 and roller 420. In some embodiments, rollers 410 and 420 are molded elastomeric wheels, such as molded polyurethane wheels. Roller 410 has a circumference with a curved profile 412, and roller 420 has a circumference with a curved profile 422. When the sheet material is not positioned between rollers 410 and 420, curved profile 412 of roller 410 contacts curved profile 422 of roller 420. When the sheet material is positioned between rollers 410 and 420, drive system 404 is configured to feed the sheet material through drive system 404 by rotating at least one of rollers 410 and 420. In the embodiment shown, the profile 406 of the sheet is arranged so that a single layer of sheet passes between rollers 410 and 420 with some deformation of the portions of the sheet on either side of rollers 410 and 420 .

[0071] In the illustrated embodiment, drive system 404 includes a shaft 414 for roller 410 and a shaft 424 for roller 420. In the illustrated embodiment, shafts 414 and 424 are substantially parallel to each other. In some embodiments, roller 410 is configured to rotate freely relative to shaft 414, while roller 420 cannot rotate relative to shaft 424. Thus, roller 420 can be driven by rotation of shaft 424, and roller 410 can rotate in the opposite direction relative to roller 420 when driven. In the illustrated embodiment, shaft 414 includes a biasing mechanism 416 positioned between one side of roller 410 and frame 402. In the illustrated embodiment, biasing mechanism 416 is configured to bias roller 410 axially along shaft 414 toward roller 420. In the illustrated embodiment, shaft 424 includes a biasing mechanism 426 positioned between one side of roller 420 and frame 402. In the illustrated embodiment, biasing mechanism 416 is configured to bias roller 420 axially along shaft 424 toward roller 410. In the illustrated embodiment, rollers 410 and 420 are offset so that when a sheet is not positioned between rollers 410 and 420, the point on roller 410 that contacts the curved profile 422 of roller 420 is not on the maximum circumference of roller 410, and the point on roller 420 that contacts the curved profile 412 of roller 410 is not on the maximum circumference of roller 420.

[0072] The conversion system 400 also includes a biasing mechanism 430 configured to bias the roller 410 toward the roller 420. In the illustrated embodiment, the biasing mechanism 430 is a compression spring that extends between the shaft 414 of the roller 410 and a post 432 fixedly coupled to the frame 402. Figure 10A and10B In the illustrated embodiment, the shaft 424 of the roller 420 is not capable of translational movement relative to the frame 402. Thus, in the illustrated embodiment, the biasing mechanism 430 is coupled between the shaft 414 of the roller 410 and the shaft 424 of the roller 420 when the biasing mechanism 430 extends between the shaft 414 of the roller 410 and the post 432. The shaft 414 of the roller 410 passes through a slot 408 in the frame 402 that permits translational movement of the shaft 414. The slot 408 permits the roller 410 to be biased toward the roller 420 when no sheet is positioned between the rollers 410 and 420. The slot 408 also permits the roller 410 to move away from the roller 420 when a sheet passes between the rollers 410 and 420, particularly when a multi-layered sheet and / or a deformed (e.g., folded or wrinkled) sheet passes between the rollers 410 and 420. In some embodiments, the biasing mechanism 430 is configured to disengage when the sheet is initially fed between the rollers 410 and 420. For example, the hook of the compression spring can be removed from the shaft 414 so that the user can manually lift the roller 410 while the user manually feeds the initial portion of the sheet through the rollers 410 and 420.

[0073] The conversion system 400 also includes a motor 434. In some embodiments, the motor can be an electric motor, a heat engine (e.g., an internal combustion engine), a chemical motor, a pneumatic motor, a hydraulic motor, or any other type of motor or engine. In the illustrated embodiment, the motor 434 is fixedly coupled to the frame 402. The motor 434 is configured to engage the shaft 424 and, when the motor 434 is operated, rotate the shaft 424. In some embodiments, the roller 420 cannot rotate relative to the shaft 424 so that the roller 420 and the shaft 424 rotate in response to the motor 434 driving the shaft 424. In some embodiments, the motor 434 is communicatively coupled to a computing device (e.g., a controller) configured to control the operation of the motor 434. For example, the computing device can control one or more of when the motor 434 operates, the speed at which the motor 434 operates, the torque generated by the motor 434, etc.

[0074] In some embodiments, the conversion system 400 may be part of a padding conversion machine that also includes a sheet material source. The sheet material source may be a roll of sheet material, a fan-shaped stack of sheet material, or any other source. The sheet material is in a substantially flat configuration in the source. The conversion system 400 is configured to feed the sheet material from the source through the drive system 404. The conversion system 400 is also configured to convert the sheet material from a substantially flat configuration to a non-flat configuration. In some embodiments, the drive system 404 alone is capable of converting the sheet material from a substantially flat configuration to a non-flat configuration. In some embodiments, the conversion system 400 includes other components, such as a hopper device or other tortuous path component, which is configured to deform the sheet material from a substantially flat configuration as the sheet material is fed from the source to the drive system 404. In embodiments where the rollers 410 and 420 are elastomeric wheels, the friction between the sheet material and the elastomeric material of the rollers 410 and 420 can increase the efficiency of the drive system 404 in feeding the sheet material through the conversion system 400.

[0075] Figure 11A and 11B A front view and a side view, respectively, of another embodiment of a conversion system 500 that can be used in a dunnage conversion machine are depicted. Conversion system 500 includes a frame 502 configured to hold components of a drive system 504. Drive system 504 is configured to draw sheet material from a source of sheet material in the dunnage conversion machine. In some embodiments, the sheet material is paper, such as kraft paper. In the illustrated embodiment, an example of a profile 506 of the sheet material is depicted between roller 510 and rollers 520 and 540. In some embodiments, rollers 510, 520, and 540 are molded elastomeric wheels, such as molded polyurethane wheels. Roller 510 has a circumference with a curved profile 512, roller 520 has a circumference with a curved profile 522, and roller 540 has a circumference with a curved profile 542. When a sheet material is not positioned between roller 510 and rollers 520 and 540, the curved profile 512 of roller 510 contacts the curved profiles 522 and 542 of rollers 520 and 540, respectively. When the sheet is positioned between roller 510 and rollers 520 and 540, drive system 504 is configured to feed the sheet through drive system 504 by rotating at least one of rollers 510, 520, and 540. In the illustrated embodiment, the profile 506 of the sheet is arranged so that a single layer of the sheet passes between roller 510 and rollers 520 and 540 with some deformation in the portion of the sheet between roller 510 and rollers 520 and 540.

[0076] In the illustrated embodiment, drive system 504 includes a shaft 514 for roller 510 and shafts 524 for rollers 520 and 540. In the illustrated embodiment, shafts 514 and 524 are substantially parallel to each other. In some embodiments, roller 510 is configured to rotate freely relative to shaft 514, while rollers 520 and 540 cannot rotate relative to shaft 524. Thus, rollers 520 and 540 can be driven by rotation of shaft 524, and roller 510 can rotate in the opposite direction relative to rollers 520 and 540 when driven. In the illustrated embodiment, shaft 514 includes a biasing mechanism 516 located between one side of roller 510 and frame 502. In some cases, biasing mechanism 516 is configured to bias roller 510 to a position substantially centered between the sides of frame 502. In the illustrated embodiment, roller 510 is offset relative to rollers 520 and 540 so that when a sheet is not positioned between roller 510 and roller 520, (i) the point on roller 510 that contacts curved profile 522 of roller 520 is not on the maximum circumference of roller 510, (ii) the point on roller 520 that contacts curved profile 512 of roller 510 is not on the maximum circumference of roller 520, (iii) the point on roller 510 that contacts curved profile 542 of roller 540 is not on the maximum circumference of roller 510, and (iv) the point on roller 540 that contacts curved profile 512 of roller 510 is not on the maximum circumference of roller 540. Additionally, when a sheet is not positioned between roller 510 and rollers 520 and 540, curved profiles 522 and 542 contact curved profile 512 on opposite sides of the maximum circumference of roller 510. This orientation helps center roller 510 between rollers 520 and 540.

[0077] The conversion system 500 also includes a biasing mechanism 530 configured to bias the roller 510 toward the roller 520. In the illustrated embodiment, the biasing mechanism 530 is a compression spring that extends between the shaft 514 of the roller 510 and a post 532 fixedly coupled to the frame 502. Figure 10A and 10BIn the illustrated embodiment, the shafts 524 of the rollers 520 and 540 are not capable of translational movement relative to the frame 502. Thus, in the illustrated embodiment, the biasing mechanism 530 is coupled between the shafts 514 of the roller 510 and the shafts 524 of the roller 520 when the biasing mechanism 530 extends between the shafts 514 of the roller 510 and the posts 532. The shafts 514 of the roller 510 pass through slots 508 in the frame 502 that permit translational movement of the shafts 514. The slots 508 permit the roller 510 to be biased toward the rollers 520 and 540 when no sheet is positioned between the rollers 510 and 520. The slots 508 also permit the roller 510 to be moved away from the rollers 520 and 540 when sheet material passes between the rollers 510 and 520, particularly when multi-layered sheet material and / or deformed (e.g., folded or wrinkled) sheet material passes between the rollers 510 and 520, 540. In some embodiments, biasing mechanism 530 is configured to disengage when the sheet is initially fed between roller 510 and rollers 520 and 540. For example, the hook of the compression spring can be removed from shaft 514 so that a user can manually lift roller 510 while the user manually feeds the initial portion of the sheet through roller 510 and rollers 520 and 540.

[0078] The conversion system 500 also includes a motor 534. In some embodiments, the motor can be an electric motor, a heat engine (e.g., an internal combustion engine), a chemical motor, a pneumatic motor, a hydraulic motor, or any other type of motor or engine. In the illustrated embodiment, the motor 534 is fixedly coupled to the frame 502. The motor 534 is configured to engage the shaft 524 and, when the motor 534 is operated, rotate the shaft 524. In some embodiments, the rollers 520 and 540 cannot rotate relative to the shaft 524, such that the rollers 520 and 540 and the shaft 524 rotate in response to the motor 534 driving the shaft 524. In some embodiments, the motor 534 is communicatively coupled to a computing device (e.g., a controller) configured to control the operation of the motor 534. For example, the computing device can control one or more of when the motor 534 operates, the speed at which the motor 534 operates, the torque generated by the motor 534, and the like.

[0079] In some embodiments, the conversion system 500 may be part of a dunnage conversion machine that also includes a sheet material source. The sheet material source may be a roll of sheet material, a fan-shaped stack of sheet material, or any other source. The sheet material is in a substantially flat configuration in the source. The conversion system 500 is configured to feed the sheet material from the source through the drive system 504. The conversion system 500 is also configured to convert the sheet material from a substantially flat configuration to a non-flat configuration. In some embodiments, the drive system 504 alone is capable of converting the sheet material from a substantially flat configuration to a non-flat configuration. In some embodiments, the conversion system 500 includes other components, such as a hopper device or other tortuous path component, which is configured to deform the sheet material from a substantially flat configuration as the sheet material is fed from the source to the drive system 504. In embodiments where the rollers 510 and 520 are elastomeric wheels, the friction between the sheet material and the elastomeric material of the rollers 510 and 520 can increase the efficiency of the drive system 504 in feeding the sheet material through the conversion system 500.

[0080] Figure 12 A side view of an embodiment of a conversion system 600 is depicted, the conversion system having a biasing mechanism arrangement that can be used in any embodiment of the conversion system disclosed herein to bias one roller toward another roller. The conversion system 600 includes a frame 602 configured to hold components of a drive system. The drive system includes rollers 610 and 620. Roller 610 has a circumference with a curved profile and roller 620 has a circumference with a curved profile. When a sheet is not located between rollers 610 and 620, the curved profile of roller 610 contacts the curved profile of roller 620. In the illustrated embodiment, the drive system includes a shaft 614 of roller 610 and a shaft (not visible) of roller 620. The conversion system 600 also includes a motor 634 configured to drive the shaft of roller 620.

[0081] The conversion system 600 also includes a biasing mechanism 630 configured to bias the roller 610 toward the roller 620. In the illustrated embodiment, the biasing mechanism 630 is a compression spring extending between a lever arm 650 and a post 632 fixedly coupled to the frame 602. The lever arm 650 is configured to pivot relative to the frame 602. In the illustrated embodiment, the lever arm 650 is fixedly coupled to a shaft 652 that passes through an opening in the frame 602. In some embodiments, the shaft 652 passes through both sides of the frame 602 and Figure 12The end of the shaft, not shown, is fixedly coupled to another lever arm on the other side of frame 602. Shaft 614 is coupled to lever arm 650. In embodiments where the other lever arm is located on the other side of frame 602, the other end of the shaft is coupled to the other lever arm. Lever arm 650 also includes a post 654, and biasing mechanism 630 is coupled between post 654 and post 632. In embodiments where the other lever arm is located on the other side of frame 602, the other lever arm may include a post, and the other biasing mechanism may be coupled between the post on the other lever arm and the post on the other side of frame 602.

[0082] exist Figure 12 In the illustrated embodiment, the shaft of roller 620 is not translationally movable relative to frame 602. Therefore, in the illustrated embodiment, when biasing mechanism 630 extends between post 654 and post 632, biasing mechanism 630 is coupled between shaft 614 of roller 610 and shaft 620. Shaft 614 of roller 610 passes through slot 608 in frame 602, which allows for translational movement of shaft 614. Slot 608 allows roller 610 to be biased toward roller 620 when no sheet is positioned between rollers 610 and 620. Slot 608 also allows roller 610 to move away from roller 620 when sheet material passes between rollers 610 and 620, particularly when multi-layered sheet material and / or deformed (e.g., folded or wrinkled) sheet material passes between rollers 610 and 620. In some embodiments, slot 608 can have an arcuate shape based on the path of movement of shaft 614 when lever arm 650 pivots about axis 652. In some embodiments, biasing mechanism 630 is configured to disengage when a sheet is initially fed between rollers 610 and 620. For example, the hook of the compression spring can be removed from post 654 and / or post 632, allowing a user to manually lift roller 610 while the user manually feeds an initial portion of the sheet through rollers 610 and 620. Clearly, in other embodiments of the conversion systems disclosed herein, the arrangement of lever arm 650 and biasing mechanism 630 can replace a biasing mechanism that biases one roller toward the other.

[0083] For purposes of this disclosure, terms such as "upper," "lower," "vertical," "horizontal," "inwardly," "outwardly," "inside," "outside," "front," "rear," and the like should be construed as descriptive and not limiting the scope of the claimed subject matter. Furthermore, the use of "including," "comprising," or "having," and variations thereof herein, are meant to encompass the items listed thereafter and their equivalents, as well as additional items. Unless otherwise limited, the terms "connected," "coupled," and "mounted," and variations thereof, herein, are used broadly and encompass both direct and indirect connections, couplings, and mountings. Terms such as "substantially," "approximately," and the like are used to mean within 5% of a target value, unless otherwise specified.

[0084] The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. However, the aspects of the present disclosure intended to be protected should not be interpreted as being limited to the specific embodiments disclosed. In addition, the embodiments described herein are considered to be illustrative rather than restrictive. It should be appreciated that others may make variations and changes, and employ equivalents, without departing from the spirit of the present disclosure. Therefore, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the present disclosure as claimed.

Claims

1. A dunnage conversion machine comprising: a source of sheet material, wherein the sheet material is in a substantially flat configuration in the source of sheet material; as well as a conversion system configured to convert the sheet from the substantially planar configuration to a non-planar configuration, wherein: The conversion system includes a drive system configured to draw the sheet material from the source and through the conversion system, The drive system includes a first roller and a second roller, The circumference of the first roller has a first curved profile, The circumference of the second roller has a second curved profile, The first roller and the second roller are arranged such that the first curved profile of the first roller contacts the second curved profile of the second roller when the sheet is not located between the first roller and the second roller, The drive system is configured to feed the sheet through the drive system by rotating at least one of the first roller and the second roller when the sheet is positioned between the first roller and the second roller, and The first roller and the second roller are offset so that when the sheet is not located between the first roller and the second roller, the point on the first roller that contacts the second curved profile of the second roller is not on the maximum circumference of the first roller, and the point on the second roller that contacts the first curved profile of the first roller is not on the maximum circumference of the second roller.

2. The dunnage conversion machine of claim 1, wherein: The first roller and the second roller are molded elastomeric wheels.

3. The dunnage conversion machine of claim 2, wherein: The molded elastomeric wheel is a molded polyurethane wheel.

4. The dunnage conversion machine of claim 1 , further comprising: A biasing mechanism is configured to bias the first roller toward the second roller.

5. The dunnage conversion machine of claim 4, wherein: The biasing mechanism includes a compression spring coupled between a shaft of the first roller and a shaft of the second roller.

6. The dunnage conversion machine of claim 5, wherein: The shaft of the first roller is movable relative to the shaft of the second roller such that the shafts of the first and second rollers remain substantially parallel to each other.

7. The dunnage conversion machine of claim 6, wherein: The shaft of the first roller is movable relative to the shaft of the second roller within a range allowing a multilayer sheet to pass between the first roller and the second roller.

8. The dunnage conversion machine of claim 5, wherein: The shaft of the second roller is coupled to a motor, and wherein the motor is configured to drive rotation of the shaft of the second roller and rotation of the second roller.

9. The dunnage conversion machine of claim 8, wherein: The first roller is capable of freely spinning, and wherein a force applied by the biasing mechanism on the shaft of the first roller causes the first roller to contact one of the sheet or the second roller such that when rotation of the second roller is driven by the motor, the first roller and the second roller rotate in opposite directions.

10. The dunnage conversion machine of claim 4, wherein: The biasing mechanism is disengageable when the sheet is initially fed between the first roller and the second roller.

11. The dunnage conversion machine of claim 1 , wherein: When the sheet is not between the first and second rollers, the points on the first roller that contact the second curved profile of the second roller are tangent to a two-dimensional tangent plane, and the points on the second roller that contact the first curved profile of the first roller are tangent to the two-dimensional tangent plane.

12. The dunnage conversion machine of claim 11, wherein: The two-dimensional tangent plane is substantially perpendicular to an axial plane, wherein the axial plane passes through an axis of the first roller and an axis of the second roller.

13. The dunnage conversion machine of claim 1 , wherein: The sheet material is kraft paper.

14. The dunnage conversion machine of claim 13, wherein: In the sheet source, the kraft paper is in fan-folded stacks or in rolls.

15. A drive system for feeding a sheet, the drive system comprising: a first roller, wherein the circumference of the first roller has a first curvilinear profile; as well as a second roller, wherein the circumference of the second roller has a second curvilinear profile; wherein the first roller and the second roller are arranged such that: The first curved profile of the first roller contacts the second curved profile of the second roller when the sheet is not between the first roller and the second roller, When the sheet is positioned between the first roller and the second roller, rotation of at least one of the first roller and the second roller causes the sheet to be fed through the drive system, and The first roller and the second roller are offset so that when the sheet is not located between the first roller and the second roller, the point on the first roller that contacts the second curved profile of the second roller is not on the maximum circumference of the first roller, and the point on the second roller that contacts the first curved profile of the first roller is not on the maximum circumference of the second roller.

16. The drive system according to claim 15, wherein: The first roller is on a first shaft, and the second roller is on a second shaft, the drive system further comprising: a third roller on the second shaft, wherein the circumference of the third roller has a third curvilinear profile; The first roller and the third roller are arranged such that the first curved profile of the first roller contacts the third curved profile of the third roller when the sheet is not located between the first roller and the third roller.

17. The drive system according to claim 16, wherein: The second and third curvilinear profiles contact the first curvilinear profile on opposite sides of the maximum circumference of the first roller when the sheet is not between the first roller and the second and third rollers.

18. The drive system according to claim 16, wherein: The first shaft and the second shaft are substantially parallel to each other.

19. The drive system according to claim 15, further comprising: A biasing mechanism is configured to bias the first roller toward the second roller.

20. The drive system according to claim 15, wherein: The first roller and the second roller are molded elastomeric wheels.

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