Field of the Invention

The present invention is related to a dunnage conversion system and method, and more particularly a dunnage conversion system with a dunnage conversion machine for producing a strip of dunnage and a coiling apparatus for coiling the strip of dunnage and a method of operating same.

Background

In the process of shipping one or more articles from one location to another, a packer typically places a type of dunnage material in a shipping container, such as a carboard box, along with the article or articles to be shipped. The dunnage material cushions or prevents or minimizes movement of the articles that might be damaged during the shipping process. Some commonly used dunnage materials include plastic airbags and converted paper dunnage material.

To promote continuous operation, many dunnage conversion machines, whether producing airbags or paper dunnage material, convert a planar sheet material into a thicker strip of dunnage that may be cut or severed to provide sections of dunnage of desired lengths. When using the dunnage material to block or brace a relatively large or heavy item during shipping, the strip of dunnage may be rolled up in a coil configuration. The coil of dunnage may then be placed in the shipping container beside, above, or below the large/heavy item to be shipped. While coils of dunnage material can be produced by hand, such a procedure may consume a significant amount of time or space and manual coiling may lead to inconsistent properties in the coil. Consequently, automated coiling mechanisms have been developed to automatically produce coils of dunnage.

International Patent Application Publication No. WO 1999/021702 A1 describes a system for coiling a strip of dunnage produced by a cushioning conversion machine. A sheet stock material provided from a roll is converted into a strip of relatively lower density cushioning material, which is then wound about rotating forks into a coil configuration.

Summary

Depending on the size, shape, and weight of the item to be shipped, a user may want to adjust the lengths of dunnage provided, whether the lengths of dunnage are formed into a coil, the density or size of the coiled strip of dunnage (also the tightness of the windings in the coil), or a combination of lengths and coils in various lengths, sizes, or densities. The dunnage conversion system includes a controller programmed to control a dunnage conversion machine and a coiling apparatus to provide a predetermined series of strips of desired lengths, and optionally coils, or a combination of lengths and coils of the desired sizes and densities automatically.

An exemplary dunnage conversion system includes a dunnage conversion machine for converting a sheet stock material into a relatively thicker and lower density (lower density than the stock material) strip or length of dunnage, and a coiling apparatus for winding a strip of dunnage into a spiral coil having a general cylindrical disk-like shape. The length of the strip of dunnage produced by the dunnage conversion machine is not fixed, but may be varied as desired. The strip may be used as a length of dunnage, or the strip may be coiled by the coiling apparatus. Similarly, the density and tightness of the windings in the coil produced by the coiling apparatus also is not fixed, but may be varied as desired. The controller is configured to control operation of the dunnage conversion machine, including the length or lengths of strips of dunnage to be produced, and the coiling apparatus, to coil or not coil each strip of dunnage and optionally the tightness or density of the coils produced by the coiling apparatus. A series of lengths of dunnage, in combination with instructions on coiling or not coiling each length and optionally instructions on the density or tightness of the windings of each coil, may be predetermined.

The system optionally may further include a supply of sheet stock material for conversion into a strip of dunnage, generally either in roll form or in the form of a rectangular fan-folded stack of sheet stock material. A exemplary sheet stock material is paper, particularly kraft paper.

The foregoing and other features are hereinafter fully described and particularly pointed out in the claims, the following description and annexed drawings setting forth in detail certain illustrative embodiments, these embodiments being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

Brief Description of the Drawings

FIG. 1 is a schematic representation of an exemplary dunnage conversion system. FIG. 2 is a perspective view of an exemplary dunnage conversion system employing a coiler.

FIG. 3 is a cross-sectional view of the dunnage conversion system of FIG. 2.

FIG. 4 is a perspective view of a portion of the coiler of FIG. 2.

FIG. 5 is another perspective view of the coiler of FIG. 4 FIG. 6 is a partial cross-sectional view of the coiler of FIG. 4 with the guide plate removed and a portion rendered transparent to reveal hidden components.

FIG. 7 is a plan view of the guide plate of the coiler of FIG. 4.

FIG. 8 is a perspective view of the cam of the coiler of FIG. 4.

FIG. 9 is perspective view of the coiler of FIG. 6 where the pair of moveable pins are in the strip receiving position.

FIG. 10 is perspective view of the coiler of FIG. 6 where the pair of moveable pins are in the coiling position. Detailed Description

Referring now to the drawings in detail, an initially to FIGS. 1-3, an exemplary dunnage conversion system 20 includes a dunnage conversion machine 22 (sometimes referred to as a “converter”), and a coiling mechanism 24 (also referred to as a coiling apparatus) for selectively coiling the strip of dunnage to provide a desired density or size of the coil. The dunnage conversion machine 22 converts a sheet stock material 30 drawn from a supply 32 into a relatively less dense strip of dunnage 34. A discrete dunnage product of a desired length 37 severed from the strip 34 (alternatively referred to as a “length of dunnage”) and then exits an outlet 36 of the conversion machine 22. The length of dunnage may be used as is or rolled or wound into a coil 38 by the coiling mechanism 24. The converter 22 may be pre programmed to produce a series of discrete dunnage products of a variety of lengths, and one or more lengths of dunnage may be wound into a coil configuration. The series of dunnage products to be produced may be predetermined to meet particular packaging needs.

An exemplary supply 32 of sheet stock material 30 includes a mobile cart 40 with one or more pairs of laterally-spaced arms 42 capable of supporting one or more rolls 44 of sheet stock material 30. An exemplary sheet stock material 30 is kraft paper, and the kraft paper may be supplied wound onto a roll, as shown, or provided in a fan-folded stack. Paper is recyclable, reusable, and composed of a renewable resource, making it an environmentally responsible choice as a stock material.

During the conversion process, the dunnage conversion machine 22 shapes and deforms the sheet stock material 30 from its planar state to form a strip of dunnage that is relatively less dense than the sheet stock material 30 from which it is produced. An exemplary dunnage conversion machine is shown in FIGS. 2 and 3. In the illustrated dunnage conversion machine 22, the sheet stock material 30 travels through a forming mechanism 46 that includes a chute 48 that converges in a downstream direction from a chute inlet 50 to a relatively smaller chute outlet 52, inwardly turning edge portions and randomly crumpling the sheet stock material as it travels through the chute 48. The crumpled stock material then passes through a feeding/connecting mechanism 54 downstream of the forming assembly 46 that both (a) pulls the sheet stock material from the supply and through the forming assembly 46, and (b) connects overlapping layers of sheet stock material to help the finished strip of dunnage maintain its shape. Once a desired length of dunnage has been produced, a separating mechanism 56 downstream of the feeding/connecting mechanism 54 separates the completed lengths of dunnage from the strip of dunnage 34. The separating mechanism 56 cuts or otherwise severs the desired length of dunnage (discrete dunnage product) from the strip 34 remaining in the dunnage conversion machine 22.

The illustrated dunnage conversion machine 22 is not the only type of dunnage conversion machine that may be employed in the system 20, however, and any dunnage conversion machine that converts a sheet stock material into a length or strip of relatively lower density dunnage may be used in this system 20.

The coiling mechanism 24, also referred to as a coiling apparatus, coiling device, or simply a coiler, lies downstream of the dunnage conversion machine 22 and in the illustrated embodiment is supported by a frame extension 62 mounted to the frame of the dunnage conversion machine 22 or to the stand 58. The coiler 24 includes a rotatable coiling fork 64 with a pair of substantially parallel coiling pins 66 (also referred to as fork pins, or simply pins). The coiling fork 64 and coiling pins 66 rotate about a central coiling axis. The rotation of the coiling fork 64 and coiling pins 66 may be driven by a motor or other driving mechanism, and the motor may be mounted in the frame extension 62. A guide surface 68 extends from the outlet 36 of the dunnage conversion machine 22 toward the coiling mechanism 24 to guide a strip of dunnage from the outlet 36 to the coiling fork 64.

In a starting orientation, the coiling fork 64 and the coiling pins 66 are configured to receive a strip of dunnage guided thereto by the guide surface 68. The guide surface 68 and the coiling pins 66 thus define a path for the strip of dunnage from the dunnage conversion machine 22. The coiling pins 66 of the coiling fork 64 generally are positioned along an axis or other line that is transverse to the guide surface 68 and to the coiling axis, preferably perpendicular to the guide surface 68, to receive a leading end of the strip of dunnage between the pins 66. Each of the pair of coiling pins 66 are aligned along a line transverse to a path of the strip of dunnage. The guide surface 68 and the coiling pins 66 are configured to allow a length of dunnage to continue on the path through the coiler without being coiled or to be withdrawn in a direction parallel to the coiling pins if the length of dunnage is not to be coiled.

Once a leading end of a strip of dunnage passes between the coiling pins 66, the coiling fork 64 can rotate to wind the strip of dunnage into a coil. The strip of dunnage typically begins being wound even as the dunnage conversion machine 22 continues to produce additional length of the dunnage strip until the desired length of dunnage is produced. After the strip of dunnage is separated at the dunnage conversion machine 22, the coiling fork 64 continues to rotate until the trailing end of the strip of dunnage joins the coil, at which point the trailing end may be secured in place. Further reference to an exemplary dunnage conversion machine and coiler can be had with reference to International Patent Application Publication No. WO 99/21702, referred to above.

Accordingly, the rotation of the coiling fork 64 must be coordinated with the speed at which the feeding/connecting mechanism 54 feeds the strip of dunnage from the dunnage conversion machine 22. The strip of dunnage generally is produced from the dunnage conversion machine 22 at a constant rate, but the rotation rate of the coiling fork 64 can be varied as a function of the size of the coil to vary the density, consistency, and other properties of the coil.

The coiler shown in more detail in FIGS. 4-8 includes an automated coiler fork that allows for the movement of the fork pins to adjust the density and size of the coil. The coiler 24 includes a guide plate 80, the pair of parallel moveable coilingpins 66, and a cam 82. The guide plate 80 is substantially flat on both sides and is coupled to a drive shaft 84 of a motor 86 for rotation. A gearbox 85 is mounted between the coiler fork and the motor 86 to adjust the speed of rotation about the coiling axis. The guide plate 80 includes radially-extending curved slots 88 for guiding the pins 66 between radially-displaced inward and outward positions. The moveable pins 66 extend in a common direction generally perpendicular to the guide plate 80. The pair of moveable pins 66 are rotatable about the common coiling axis to wind a strip of dunnage into a coil. The coiling axis generally is parallel to the direction in which the pins 66 extend. The moveable pins 66 extend through respective slots 88 and are each coupled to a U-shaped pin mount 90 in approximately the middle of the U-shape. One end of each pin mount 90 is connected to the guide plate 80 in close proximity to an outer edge of the guide plate 80.

The cam 82 includes a protruding outer rim 92 within which the guide plate 80, pin mounts 90, and movable pins 66 are received. The cam 82 includes several curved control or bearing surfaces recessed from a front face of the outer rim 92. The pin mounts 90 follow the features of the surface of the cam 82. This interaction between the pin mounts 90 and the cam 82 causes the parallel pins 66 to be moved along the radially-extending curved slots 88 of the guide plate 80 from a strip receiving position to a coiling position radially inwardly disposed relative to the strip receiving position. The pins 66 and are spaced relatively closer together in the coiling position than in the strip receiving position. The control surfaces include a grooved spiral surface 94 that a portion of the pin mounts 90 rides against as the guide plate 80 rotates relative to the cam 82. The grooved spiral surface 94 is defined by a groove in the cam 82 with a varying depth, including ramped ends 96 that stop the pin mounts 90 from moving, thereby placing the pins 66 in the coiling position.

Referring now to FIG. 9, during operation of the dunnage conversion machine 22 (FIGS. 2 and 3), the leading end of the strip of dunnage (not shown) is advanced between the pair of moveable pins 66, which are located at a strip receiving position. Once the strip of dunnage is received between the moveable pins 66, the motor 86 (FIGS. 4-6) drives the rotation of the guide plate 80 about the coiling axis (FIGS. 4 and 5) (e.g., clockwise). The pin mounts 90 will follow the control surfaces of the cam 82, causing the pair of pins 66 to move from the strip receiving position to the coiling position radially inwardly disposed relative to the strip receiving position as shown in FIG. 10. Once the pin mounts 90 reach the ends 96 of the grooved spiral surface 94 (FIG. 8) of the cam 82, rotation of the coiling fork 64 about the coiling axis winds the strip of dunnage into a coil.

As mentioned above, the pins 66 are located closer to each other when positioned in the coiling position than when positioned in the strip receiving position. Moving the pins 66 closer together increases the density of the center of the resulting coil, and also reduces the outer diameter of the resulting coil for the same number of rotations. The inherent resilient nature of the strip of dunnage allows the coiler to more tightly coil the strip to increase the density of the coil relative to the density of the strip of dunnage.

Once a desired length of the strip of dunnage has been produced, the separating mechanism 56 (FIG. 3) in the dunnage conversion machine will sever the desired length of dunnage from the remaining stock material and as the trailing end of the length of dunnage reaches the coil it may be secured in place, such as with tape. An operator may then place the coiled strip of dunnage into a box or other container for packing purposes.

After the coil is removed from the coiling pins 66, the coiling mechanism 24 may rotate in the opposite direction from coiling (e.g., counterclockwise), to move the pin mounts 90 back along the control surfaces of the cam 82, and return the pair of pins 66 from the coiling position to the strip receiving position. The coiling mechanism 24 also rotates the coiling fork 64 about the coiling axis to the strip receiving position, aligning the pins 66 along an axis across the path of the strip of dunnage exiting the dunnage conversion machine 22 and guided to the coiling mechanism 24 by the guide surface 68. As with the dunnage conversion machine, the system is not limited to the illustrated coiling mechanism 24. The coiling mechanism, however, must be configured to allow a length of dunnage to be removed from the system without coiling.

In summary, a dunnage conversion system includes a conversion machine, a coiling mechanism, and a controller. The conversion machine includes a conversion assembly that converts a sheet stock material into a strip of dunnage that has a density that is lower than the density of the stock material. The coiling mechanism is arranged to receive the strip of dunnage from the conversion machine, and includes rotatable coiling elements that can selectively wind the strip of dunnage into a coil configuration or allow a length of dunnage to be removed without coiling. The controller is in communication with the conversion machine and the coiling mechanism and controls operation of the conversion assembly to produce a plurality of discrete lengths of dunnage of a desired length and controls the coiling mechanism to selectively coil one or more of the plurality of lengths of dunnage.

Although the invention has been shown and described with respect to a certain illustrated embodiment or embodiments, equivalent alterations and modifications will occur to others skilled in the art upon reading and understanding the specification and the annexed drawings. In particular regard to the various functions performed by the above described integers (components, assemblies, devices, compositions, etc.), the terms (including a reference to a "means") used to describe such integers are intended to correspond, unless otherwise indicated, to any integer which performs the specified function (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated embodiment or embodiments of the invention.