Patent Application
20100108732
The present disclosure relates to machines commonly referred to as bundle breakers or bundle separators, which separate a plurality of stacked sheets, particularly along a separation path or a nick line. More particularly, the present disclosure relates to improvements for bundle breakers.
Bundle separators or bundle breakers separate a plurality of stacked sheets, or bundles, from a log of stacked sheets. Each sheet is divided by one or more weakened paths or separation paths, and similarly, each log is divided by one or more weakened paths or separation paths. Bundle breakers in the corrugated board industry are typically located in a production line between a sheet stacker on the upstream side and a load former, which arranges the bundles in pallet loads, on the downstream side.
A wide variety of products are manufactured in elongated sheets and divided into smaller segments through the use of weakened paths in the sheets created by, for example, scoring, indenting, nicking, tabbing, or punching. Such products include composition house roofing shingles, glass plates, paper, plastic, and corrugated board used in constructing boxes and packaging material. Weakened paths are provided since it is desirable, with such products, to impose tensile stress required to separate the sheets along the selected paths rather than subjecting the entire sheet to tensile stress with random separation.
In the manufacture of corrugated boxes and other corrugated goods, for example, a large sheet of corrugated material is passed through a machine which will die cut the blank or flat shape of corrugated boxes, or other objects that are to be constructed, from the sheet of corrugated material. The sheets of corrugated material may be die cut in a press, which acts in the manner of a die cutting machine, to stamp the pattern of the blank into the sheets. Alternately, the sheets of corrugated material may pass through a rotary die which will cut and/or emboss the blank pattern of the final shape of the knock-down cartons or the like to be made from the sheets.
To simplify handling of the corrugated material, the die cut blanks are not separated completely from the sheet, but are left partially joined along adjacent edges which will separate under tension to produce the individual blanks for later formation into cartons, boxes, or other objects. Because several blanks may be separated from a single sheet, there is an increase in efficiency from handling a single sheet as compared to a multitude of blanks cut from the sheet.
At some point, the blanks defined by the rotary press or the platen die press will need to be separated so that they may be individually bundled and shipped or further processed into finished goods. In the manufacture of corrugated goods, it is desirable to enhance efficiency and throughput by minimizing handling steps. It is therefore desirable to separate the blanks from the primary sheet or sheets in a minimal number of steps.
One method to minimize the number of handling steps is to collect several sheets into a stack, or log, and then separate the log into bundles. The more sheets in a log of corrugated material that can be handled at one time, the more efficient the process will be. However, as more sheets are accumulated into a log to increase throughput, a larger force will be required to separate a log along a defined separation path.
Some die cutting processes will cut away portions of the corrugated sheet along the separation path of the blank to be separated from the sheet. In the cut away area, small tabs will be left so the blank does not separate from the sheet. The small tabs are termed “nicks,” and a sheet with die cut blanks held in place by nicks is termed a “nicked sheet.” Alternately, the die may impress a crease along the sheet or partially cut through the sheet to define the separation path. Either of these processes will create an area of weakened tensile strength such that when the sheet is subjected to a tensile force acting generally in the plane of the sheet, the sheet will tear or separate along the defined separation path.
One method for separating a bundle of blanks from a log of nicked sheets consists of grasping the log of corrugated sheets along either side of a separation path and then pulling the two grasped portions apart to sever the bundle from the remaining log. As the stacks include an increasing number of sheets, more tensile force is required to separate the bundle from the log to increase the rate of throughput. In order to achieve greater tension forces, larger grasping or clamping forces must be applied to the stack.
An example bundle breaker can include a first conveyor for conveying the log of stacked sheets, the first conveyor having an upstream end for receiving the log of stacked sheets and a downstream end. A second conveyor includes an upstream end positioned immediately adjacent the downstream end of the first conveyor. The bundle breaker includes a first clamp or platen mounted for vertical reciprocating movement generally above the first conveyor and a second clamp or platen mounted above the second conveyor for vertical reciprocating movement generally above the second conveyor. The platens above the first and second conveyors are allowed to move away from each other once a log of stacked sheets has been clamped on either side of the separation path in order to separate a bundle of stacked sheets from the log of stacked sheets. Several embodiments of bundle breakers are known, such as the bundle breakers described in U.S. Pat. No. 5,791,539, U.S. Pat. No. 6,019,267, U.S. Pat. No. 6,655,566, and U.S. Pat. No. 7,370,783, each of which is hereby incorporated by reference herein in its entirety. Nonetheless, the above-identified prior art bundle breaker systems do not provide the most efficient handling of logs of stacked sheets, wherein the sheets are die cut or embossed with irregular or non-linear separation paths.
Thus, there exists a need in the art for an apparatus for separating bundles of blanks from a log of nicked sheets having such blanks die cut within the individual sheets and which allows the platens to be positioned generally as closely as possible to the separation path to allow separation with less force and less risk of damage to the materials. There is a need in the art for an improved bundle breaker including platen shoes, or guided rails, that can be moved longitudinally to position clamping force generally as close to the separation path as possible.
The present disclosure, in one embodiment, relates to an apparatus for separating bundles from a log traveling along a conveyor, the log having a plurality of stacked sheets with a weakened separation path, and the weakened separation path of each sheet being substantially aligned in the stack. The apparatus includes a first platen mounted for vertical reciprocating movement generally on a first side of the separation path and a second platen mounted for vertical reciprocating movement generally on a second side of the separation path, each platen having a plurality of moveable guided rails. The second platen is also mounted for movement away from the first platen. The moveable guided rails on each of the first and second platens are each independently moveable in the upstream or downstream direction of travel of the log.
The present disclosure in another embodiment relates to an apparatus for separating bundles from a log including a plurality of stacked sheets having a top surface, each sheet having a weakened irregular separation path, the weakened irregular separation path of each sheet being substantially aligned in the stack and defining a downstream bundle for separation from an upstream portion of the log. The apparatus includes a first platen and a second platen, each having a plurality of guide rails, each of the guide rails being independently moveable in the upstream or downstream directions. The first platen releasably clamps down on the upstream portion of the log, and the second platen releasably clamps down on the downstream bundle. Generally the entirety of the guide rails of the first platen remain on the upstream side of the weakened irregular separation path and generally the entirety of the guide rails of the second platen remain on the downstream side of the weakened irregular separation path during separation of the downstream bundle from the log.
The present disclosure, in another embodiment, relates to a method for separating a bundle of stacked sheets from a log of sheets. The method includes conveying the log of sheets until a weakened separation path defined across the log of sheets is brought to a desired position. A plurality of moveable guided rails provided on each of first and second platens are positioned such that leading edges of the guided rails substantially align with the profile of the weakened separation path. The log of sheets is clamped on one side of the weakened separation path under the plurality of guided rails of the first platen and on the other side of the weakened separation path under the plurality of guided rails of the second platen. Substantially no portion of the weakened path is covered by a guided rail.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the present invention, it is believed that the invention will be better understood from the following description taken in conjunction with the accompanying Figures, in which:
The present disclosure relates to novel and advantageous bundle breakers or bundle separators for separating a plurality of stacked sheets, particularly along a weakened path, separation path, or nick line. More particularly, the present disclosure relates to novel and advantageous improvements for bundle breakers.
An improved bundle breaker according to an embodiment of the present disclosure allows platen shoes, or guided rails, to be moved longitudinally, or in the direction of the material path, to clamp generally as close to the separation path as possible, including generally as close as possible to each portion of the separation path of nested bundles substantially along the length of the separation path. An improved bundle breaker according to an embodiment of the present disclosure works on both non-nested bundles or nested bundles; however, an increased benefit can be achieved particularly with regard to nested bundles. Additionally, an improved bundle breaker according to an embodiment of the present disclosure works for separating multiple stacks simultaneously, including where the multiple stacks are of inconsistent heights.
Currently bundle breaker machines move upstream platens and downstream platens as single units. This means the edge of each platen nearest the nick line will orthogonally traverse the travel path of the sheets from one side to another in an essentially linear edge. In contrast, a bundle breaker of the present disclosure allows individual platen shoes to move longitudinally relative to each other so that the edges of the platen shoes nearest the separation path do not always line up linearly/orthogonally across the travel path of the sheets. This allows the platens to generally conform to the shape of the nested bundle, apply force closer to the separation path, and reduce damage on the materials being separated.
Bundle breakers may be used in the manufacture of a wide variety of products, such as but not limited to composition house roofing shingles, glass plates, paper, plastic, and corrugated board used in constructing boxes and packaging material. While the various embodiments of the present disclosure are described herein as applying primarily to corrugated material, it is understood that the various embodiments of a bundle breaker described herein can be used equally effectively with uncorrugated fiberboard, sheets of plastic, sheets of fiberglass, or other suitable semi-rigid material which lends itself to tearing in tension, such as those listed above. It is also understood that the various embodiments of a bundle breaker described herein may apply equally well to thin sheets of wood.
In the manufacture of cardboard boxes and other items made of corrugated material, for example, a large sheet of corrugated material can be processed in a die or other cutting device to cut one or more blanks (flat patterns) from the corrugated sheet.
Current processes for partially cutting without separating the blanks from the entire sheet may include leaving small tabs 22 along the die cut separation path 18, 20 or embossing or partially cutting along the separation path 18, 20 so as to create “nicks” in the sheet 10. As noted above, a sheet having partially cut blanks may be referred to herein as a “nicked sheet.” Alternately, the die may impress a crease along the sheet or partially cut through the sheet to define the separation path.
At some point in the manufacturing process, it may be desirable to separate the defined blanks from the rest of the nicked sheet 10 so that the blanks 12, 14, 16 may be shipped individually or may be further constructed into completed cartons and the like. As illustrated in
Oftentimes, the separation path 18, 20 will orthogonally traverse the sheet from one side to another creating an essentially straight separation path 18, 20, as illustrated in
In bundles with a generally straight separation path 18, 20, a system of upstream and downstream platens that are close together and close to the straight separation path 18, 20 can be quite effective. However, with nested bundles, the effectiveness of the prior art systems deteriorates due to a portion of the separation path 36, 38 being clamped between the upstream 42 and downstream 42 platens, as shown in
In certain embodiments, it can be desirable that the bundles are clamped and controlled as near to the separation path as possible. For instances where nested bundles must be separated, the separation can be most effective when the platens follow the profile of the separation path. The present disclosure relates particularly to an improvement for a bundle breaker, and more particularly to a bundle breaker having improved platens for efficiently and accurately separating bundles, particularly nested bundles, from a stack.
In an effort to increase the efficiency of separating nested bundles using upstream 52 and downstream 54 platens, guided rails 56, also referred to herein as platen shoes, can be used to adapt the shape of the platens 52, 54 to generally that of the separation path 36. In one embodiment, illustrated in
The leading edges 57—the edges of each of the rails 56 of each platen 52, 54 that is nearest the separation path—of the individual rails 56 can be set up to accommodate the particular separation path 36 profile of the nested bundles at the beginning of a log of sheets, for example, and may generally be maintained in that position (except vertically as required for clamping/grasping) until the next log of sheets is presented to the bundle breaker. Alternatively, the individual rails 56 can be set up dynamically upon presentation of each separation path to a separation area, such as but not limited to an area lying generally between the upstream 52 and downstream 54 platens, or at any other suitable time. The individual rails 56 may be set up manually or may be set up automatically by the bundle breaker using appropriate control hardware and/or software. In some embodiments, the bundle breaker may include sensors, such as optical sensors, for determining the separation path 36, 38 to automatically determine and set up the alignment of the individual rails 56, in some cases at each presentation of a separation path.
In one embodiment, both the upstream platen 52 and downstream platen 54 can be provided with multiple rails, e.g., 56a, 56b, 56c, that are paired with a rail, e.g., 56d, 56e, 56f, respectively, on the opposite platen. However, in other embodiments, the rails 56 of the upstream platen 52 do not necessarily need to be paired with the downstream platen 54. The rails 56 can move upstream and downstream, and all rails 56 can move independent of all other rails. In scenarios where the separation path 18, 20 is straight across the stack 30, a leading edge of the rails 56 can be substantially aligned orthogonally across and close to the separation path.
However, when separating nested bundles, the rails 56 can adjust upstream or downstream so that the leading edge of each rail 56 is substantially near its respective portion of the separation path 36 profile when in a clamped position, as illustrated in
As can be seen in
As can also be seen in
As described above, the individual rails 72 can be set up to accommodate the particular separation path 36 profile of the nested bundles at the beginning of a log of sheets, for example, and may generally be maintained in that position (except vertically as required for clamping/grasping) until the next log of sheets is presented to the bundle breaker. Alternatively, the individual rails 72 can be set up dynamically upon presentation of each separation path between the upstream and downstream platens or at any other suitable time. The individual rails 72 may be set up manually or may be set up automatically by the bundle breaker using appropriate control hardware and/or software. In some embodiments, the bundle breaker may include sensors, such as optical sensors, for determining the separation path 36, 38 to automatically determine and set up the alignment of the individual rails 72, in some cases at each presentation of a separation path. In some embodiments, where the individual rails 72 are automatically aligned, the handle 82 may be eliminated, or may be used as a manual overdrive for the air/fluid bladder 80.
Components of the bundle breaker, including but not limited to the platens, guided rails, air bladders, conveyors, etc., may be implemented by actuating the components by use of solenoids, relays, and other control schemes known for actuating electric motors, hydraulic and pneumatic actuators, and other mechanisms necessary for actuating machinery.
In the first step 102 of one method of separating a bundle from a log or stack of sheets according to the present disclosure, a stack of sheets 30 of material from which a bundle 32 is to be separated is urged forward in the downstream direction by conveyor, which typically may comprise two separate conveyors, one generally below the upstream platen 52 and one generally below the downstream platen 54 of the bundle breaker. However, any suitable means of conveying the stack of sheets can be used to move the stack of sheets in the downstream direction. The stack of sheets 30 can be conveyed into the bundle breaker until the first separation path 18, 20, 36, 38 is brought to the desired position in the bundle breaker. In some embodiments, the desired position may be defined by an area lying generally between the upstream 52 and downstream 54 platens. However, the desired position may be defined at any other suitable location, such that the separation path between the bundle 32 and the remainder of the stack 30 is positioned at the desired position. Once the separation path has been located to the desired position, the conveyor(s) may be stopped and the stack 30 held stationary in the bundle breaker.
In the second step 103, it may be determined whether the guided rails 56 need to be set up or re-set up. For example, in step 104, according to one embodiment, if the bundle 32 to be separated from the stack of sheets 30 will be the first bundle 32 separated from the stack 30, then each of the individual guided rails 56 of each of the upstream 52 and downstream 54 platens may be set to its desired longitudinal position according to the separation path profile. If the separation path is substantially linear across the stack 30, then the guided rails 56 may be aligned substantially linearly so as to substantially align with the separation path 18, 20 of the stack. However, if the separation path is irregular, then the guided rails 56 may be moved longitudinally to substantially align with the separation path 36, 38 profile. As stated above, the guided rails 56 may be aligned manually or may be aligned automatically by the bundle breaker using appropriate hardware and/or software. In some embodiments, the bundle breaker may include sensors, such as optical sensors, for determining the separation path 18, 20, 36, 38 to automatically determine and automatically set up the alignment of the individual rails 56.
In many embodiments, the separation path 18, 20, 36, 38 between each bundle and the remaining stack 30 may be generally similar, if not substantially identical. Therefore, if the bundle 32 to be separated from the stack of sheets 30 will not be the first bundle 32 separated from the stack 30, but instead is a subsequent bundle, then each of the individual guided rails 56 of each of the upstream 52 and downstream 54 platens may already be set to its desired longitudinal position. In such an embodiment, no further alignment of the guided rails 56 is necessary, and step 106 (described below) can proceed following the determination in step 103.
However, in some embodiments, the separation path 18, 20, 36, 38 between each bundle and the remaining stack 30 may be generally different, or alternate or randomly alternate between two or more configurations throughout the stack. Similarly, each of the individual guided rails 56 of each of the upstream 52 and downstream 54 platens may, even where the separation path 18, 20, 36, 38 between each bundle and the remaining stack are generally similar, need to be realigned or adjusted as the stack 30 continues to move through the bundle breaker and new separation paths are continuously presented. Therefore, in some embodiments, each of the individual guided rails 56 of each of the upstream 52 and downstream 54 platens may be set to its desired longitudinal position at each presentation of a separation path 18, 20, 36, 38 or at predetermined or random intervals of separation paths 18, 20, 36, 38 in order to accurately align the guided rails 56 to the specific separation path 18, 20, 36, 38 to be separated. As stated above, the guided rails 56 may be aligned manually or may be aligned automatically by the bundle breaker using appropriate hardware and/or software. In some embodiments, the bundle breaker may include sensors, such as optical sensors, for determining the separation path 18, 20, 36, 38 to automatically determine and set up or readjust the alignment of the individual rails 56.
Once the guided rails 56 are aligned to their desired longitudinal position and once the separation path is brought to the desired position, the upstream 52 and downstream 54 platens can be actuated and lowered, in a generally vertical direction, to a position where the stack 30 is appropriately clamped or grasped between the platens 52, 54 and the conveyors or a set of lower platens, as indicated by step 106 of
After the specified clamping force is achieved, the upstream 52 and downstream 54 platens can be forced apart, as shown in step 108 of
In one embodiment, indicated in step 110, once the bundle 32 has been separated from the remainder of the stack 30, the platens 52, 54 may be unclamped from the bundle 32 and stack 30. In step 112, the bundle 32 and stack 30 may be unclamped by actuating and raising the upstream 52 and downstream 54 platens in a generally vertical direction away from the bundle 32 and stack 30.
In other embodiments, the bundle 32 and/or stack 30 may be unclamped prior to returning the platens to a pre-separation position so that any sheets for which the separation line was not entirely aligned correctly within the separation area will be free to slide within the stack 30, rather than being crushed by the sheets in the bundle 32 as the bundle is returned to its pre-separation position with the downstream platen 54.
In step 114, the separated bundle 32 and the remainder of the stack 30 can be advanced in the downstream direction by conveyor such that the next separation path 18, 20, 36, 38 in the stack 30 is brought to the desired position, as described above. In one embodiment, the bundle 32 may be conveyed in the downstream direction first, and after a slight delay, the remainder of the stack 30 may follow in the downstream direction. Advancing of stack 30 can preferably be done after a delay to assure that the separated bundle 32 will completely exit the bundle breaker conveyor before the stack 30 is advanced and positioned for the next separating cycle.
Steps 102 through 114 may then be repeated until the remainder of the stack 30 is a single bundle. At that point, there is no remaining stack 30 for the bundle to be separated and rather than repeating steps 104 through 112, which are steps required for breaking a bundle from the remainder of the stack, the remaining stack portion can be merely advanced through the bundle breaker with the previous bundle separated from the stack.
Using the various embodiments of bundle breakers and methods for separating a bundle 32 from a stack of sheets 30 described herein, throughput may be maximized. Using platens having longitudinally moveable guided rails 56 as described above, the force required to initiate separation of the bundle 32 to be separated from the stack 30 may be reduced. This minimizes the risk of damage to the stack 30 by clamping or grasping the stack 30 too tightly.
Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, in some embodiments, no predefined weakened separation line may be required for certain relatively brittle, or soft or malleable, materials. Using platens having longitudinally moveable guided rails may further assist in separating these materials along an appropriate separation path.
This application claims priority to U.S. Provisional Application No. 61/102,495 filed on Oct. 3, 2008, the contents of which are incorporated in their entirety herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61102495 | Oct 2008 | US |
