Patent Description:
Clamshell die presses are often used to cut substrate work pieces, such as cardboards, plastic sheets, corrugated boards etc., into products of different shapes. These products can be used for different commercial purposes. A clamshell die press may include a frame (or base) for supporting a pair of platens made of steel. The pair of platens may include a fixed platen that is secured to the frame, and a moving platen that moves along a track between a fully open (an inoperative) position and a substantially close (an operative) position relative to the fixed platen. The fixed platen may provide a substantially flat working surface on which the work pieces to be cut are placed. An inner surface of the moving platen may include mounting points at which tooling can be mounted. The tooling can be the cutting blades that may cut the work pieces placed on the working surface of the fixed platen at the operative position. At the inoperative position, one end of the moving platen is pushed away from the fixed platen to allow an operator to place a work piece on the fixed platen. At the operative position, the moving platen is pushed down towards the fixed platen with force to enable the tooling to cut through the work piece, thus forming the products. In <CIT>), an improvement is made to a die cutting press and to the method of die cutting in a press by providing two opposing and oppositely driven clamping bars which move together to clamp the die board and to accurately position the clamped die board at a predetermined location within the press. The press is operated to determine the adequacy of the cut produced by the die in sheet material fed into the press. If the cut is unsatisfactory, the opposing clamp bars are quickly driven apart thereby releasing the die board. The die board can be removed from the press and then manipulated or modified to cure any imperfection in the cut. The modified die board is then reinserted into the press and accurately repositioned at the predetermined location within the press by driving the opposing clamping bars towards each other against the die board.

From <CIT> there is known a conductive cutting pad of solid polyurethane cast about a soft metal, cellular structure so that cell walls of the structure extend between cutting surfaces on the pad. From <CIT> there is known a selection of the cutting rule which results in blade load force reduction.

The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

The current die presses use steel blades having certain tooth profiles to cut through work pieces. During cutting, the steel blades are pressed with force (measured in tonnages) against a work piece. The downward force can cause steal blades cutting through the work piece until the blades strike against (i.e., contact with force) the working surface of the fixed platen. To make a clean cut, it is desirable for the steel blades to apply an even pressure on the work piece until the work piece is cut evenly and cleanly. By pressing the moving platen against the fixed platen, the steel blades compress the work piece until an explosion (clean cut) occurs. To create an even and level load so as to achieve the cut through, an operator needs to prepare a flat working surface on the fixed platen because the working surface can become uneven (due to knife wears) and the uneven working surface may cause unclean cuts at those uneven areas. The preparation process may take anywhere from <NUM> to <NUM> minutes or more of the operator's time.

Additionally, the current steel-to-steel cut can generate high-pitch and high-decibel noise at the explosion. This noise associated with die cutting is a type of working hazard for the die press operator. Also, current die cutting requires the application of a high-tonnage force to compress the work piece against the working surface of the fixed platen. The generation of the high-tonnage force consumes a large amount of energy. Therefore, there is a need to improve the current die cutting.

Instead of the hard steel-to-steel die cutting as currently used in clamshell die presses, embodiments of the present disclosure provide a soft die cutting system that includes a set of soft padding blocks. These padding blocks may be configured into a pad mounted on the top of the working surface of the fixed platen. Each padding block may include a steel backing and a padding layer bonded to the steel backing. The steel backing, when mounted, may be affixed to the working surface of the fixed platen using binding agents (e.g., a magnetic layer) while the padding layer faces the direction of the moving platen or the blades. One or more pieces of padding blocks may be placed on the working surface of the fixed platen to form a pad on top of the fixed platen. The padding blocks may be arranged in a variety of combinations to form the pads of different shapes, thus covering different areas on the working surface. Work pieces to be cut may be placed on the pad formed by the padding blocks to enable a soft cut of the work pieces.

Since padding blocks may be easily rearranged into pads having different area coverages, the time required to provide the cutting surface on the fixed platen is significantly reduced, compared to the time traditionally spent on preparing the working surface of the fixed platen. Further, because the blades of the die cutter may cut through the work pieces into the soft padding layers of the padding blocks, the press load (or pressing force tonnage) needed for cutting various substrates may be significantly reduced. The deeper cuts into the soft padding layers can result in cleaner cuts (i.e., fewer angel hairs attached to the products). Further, because of the soft padding layer, the steel blades do not directly scratch the working surface of the fixed platen, the noise associated with the die cutting can be reduced significantly, thus improving the working environment for the die press operators.

<FIG> illustrates a clamshell die press <NUM> according to an embodiment of the present disclosure. As shown in <FIG>, the die press <NUM> may include a frame <NUM>, a fixed platen <NUM>, and a moving platen <NUM>. Die press <NUM> may be secured to the ground through frame <NUM>, and fixed platen <NUM> may be securely mounted onto frame <NUM>. Fixed platen <NUM> may be made of steel and may provide a substantially level working surface with respect to the ground. Moving platen <NUM> may include a first end <NUM> that is engaged with a track and a second free end <NUM> can be in an open position or a close position with respect to the working surface of fixed platen <NUM>. At the open position, the free end <NUM> of the moving platen <NUM> is away from fixed platen <NUM>, whereas at the close position, the free end <NUM> of the moving platen <NUM> is pushed to the fixed platen <NUM> to enable an inner surface of moving platen <NUM> substantially parallel to the working surface of the fixed platen <NUM>. While at the close position, there is a gap space between the working surface of fixed platen <NUM> and the inner surface of moving platen <NUM>. In one embodiment, die press <NUM> may be a regular clamshell press that has a small gap of approximately <NUM> and <NUM> (one to one and half inches). In another embodiment, die press <NUM> may be a Widemouth™ die press that has an adjustable gap between <NUM> and <NUM> (one and three inches).

Moving platen <NUM> may be transitioned by an operator between the open position and the close position via a track path using gears and arms. In one embodiment, tooling <NUM> may be installed on the inner surface (i.e., the surface of moving platen <NUM> that faces the working surface of fixed platen <NUM>) for die cutting. Tooling <NUM> may include steel blades <NUM> and rubber ejections <NUM> that surround the steel blades <NUM>. Steel blades <NUM> may be installed on the inner surface of moving platen <NUM> to create different cutting patterns. During die cutting, steel blades <NUM> may cut work pieces into products of different shapes, while the rubber ejections <NUM> may help release the finished products from the steel blades <NUM>.

In one embodiment, instead of mounting work pieces directly onto the working surface of fixed platen <NUM>, a soft pad <NUM> may be mounted on the working surface of fixed platen <NUM> to provide a soft cutting surface to blades <NUM>. Pad <NUM> may be formed by mounting one or more padding blocks <NUM> on the working surface of fixed platen <NUM>. In one embodiment, padding blocks <NUM> used to form pad <NUM> may have substantially the same geometric contour shape. In another embodiment, padding blocks <NUM> used to form pad <NUM> may have different contour shapes. Different combinations of padding blocks <NUM> (of the same shape or different shapes) may produce pad <NUM> covering different areas on the working surface of fixed platen <NUM>.

<FIG> illustrates a padding block <NUM> according to an embodiment of the present disclosure. Padding block <NUM> can have different contour shapes. In one embodiment as shown in <FIG>, the edge contour of padding block <NUM> may be rectangular. In other embodiments, the edge contour of padding block <NUM> may be other geometric shapes including, for example, triangles, squares, and circles.

Padding block <NUM> may include two or more layers composed of different materials. In one embodiment, as shown in <FIG>, padding block <NUM> may include a backing layer <NUM> and a padding layer <NUM>. Backing layer <NUM> may be composed of hard metals such as steel. Padding layers <NUM> may be composed of softer materials such as, for example, Urethane, rubber, ultra-high-molecular-weight (UHMW) polyethylene, or other materials that have a hardness measurement in terms of Shore durometer ranging from <NUM> A to <NUM> D. The materials of the padding layer <NUM> are softer than the blades, and allow the blades cut into the padding layer <NUM>. Padding layer <NUM> can be bonded to backing layer <NUM> by chemical reaction. For example, padding layer <NUM> may be bonded to steel backing layer <NUM> by using heat-activated adhesive chemical agents. Once bonded, padding layer <NUM> is secured to backing layer <NUM>.

Different combinations of padding blocks <NUM> may form pad <NUM> covering areas of different contour shapes. <FIG> illustrates some exemplary arrangements of padding blocks <NUM>. These arrangements of padding blocks can form pads of different shapes. Because the padding blocks <NUM> can be conveniently mounted at different locations on the working surface of the fixed platen <NUM>, the time to prepare and make ready the cutting surface can be reduced significantly. The time to prepare the cutting surface now includes the time to mount and/or reposition the padding blocks but without the need to level the surface of the fixed platen <NUM>. Further, the impression force applied by the die press <NUM> to padding blocks <NUM> may be experimented with (e.g., increasing incrementally) until satisfactory cuts on work pieces are achieved. This process to adjust the impression force typically takes no more than two minutes. Thus, the soft cut system may significantly reduce the time to start the operation of die press <NUM>.

The steel backing layer <NUM> of padding blocks may be used to secure padding blocks <NUM> onto the fixed platen <NUM>. For example, magnetic force may be used to secure padding blocks <NUM> to the fixed platen <NUM>. As shown in <FIG>, in one embodiment, a thin, double-sided magnetic layer <NUM> may be used to provide the magnetic force to secure the metal backing layers of padding blocks to fixed platen <NUM>. Magnetic layer <NUM> may be mounted on the working surface of fixed platen <NUM>, and padding blocks <NUM> may be mounted on top of magnetic layer <NUM> so as to bind pad <NUM> formed by padding blocks <NUM> to the fixed platen <NUM> with the magnetic force. In addition, metal backing layer <NUM> may also provide a backbone for the soft material of padding layer <NUM> to prevent distortion during die cut. In another embodiment, backing layer <NUM> may be composed of magnetized metal (e.g., magnetized steel). The magnetized backing layer <NUM> may be mounted onto a metal working surface of fixed platen <NUM>, secured by the magnetic force.

Padding layer <NUM> of padding blocks <NUM> may be composed of different types of materials that have a variety of hardness measurements. Thus, padding blocks having padding layers of different hardness measurements may be employed to form pad <NUM>. In one embodiment, the type (i.e., hardness of the padding layer) of padding blocks may be selected based on the tooth profiles of the blades <NUM> and/or the material of the work pieces being cut. The type of padding blocks <NUM> is selected to enable a match of the hardness of padding layer with the tooth profiles of blades <NUM> so that the match may produce the optimal cutting results.

For example, in steel rule die cut, blades may be specified according to a tooth profile including certain geometrical properties of the blade. <FIG> illustrates some blade profiles that may be used in steel rule die cut. As shown in <FIG>, a tooth profile <NUM> may include a tooth portion <NUM> and a gullet portion <NUM>. The tooth portion <NUM> includes tooth tips that can cut into work pieces, and the gullet portion <NUM> includes the curved area at the base of the teeth. The tooth profile <NUM> may be associated with certain geometrical properties that may determine how the blade cuts into work pieces. For example, the tooth profile may include a tooth pitch <NUM> that measures the distance from the tip of one tooth to the tip of the next tooth, and a gullet depth <NUM> that measures the distance between the tooth tip and the bottom point of the gullet. Further, tooth profile may include different contour shapes for the teeth and gullets of the blade. As shown in <FIG>, for example, the blade may include, but not limited to, radius teeth and radius gullets <NUM>, pointed teeth and V-shaped gullets <NUM>, and pointed teeth and radius gullets <NUM>. All these properties associated with tooth profile <NUM> may be used as parameters that determine the hardness measurement of the padding layer that best matches the blade.

The geometrical properties of tooth profile <NUM> may be used to determine the pad that best matches to the tooth profile. To prepare for die cuts, the tooth profile may be selected to provide the desired edge quality on the work pieces using the least cutting force. Then, the hardness of the padding layer may be selected to match the tooth profile of the blades being used. <FIG> shows exemplary tooth profiles and padding layers with matching hardness measurements according to an embodiment of the present disclosure. As shown in <FIG>, large toothed profile <NUM> may be matched a padding layer composed of materials measured at approximately <NUM> Shore A; an intermediate-sized toothed profile <NUM> may be matched a padding layer composed of materials measured at approximately <NUM> Shore A; a small toothed profile <NUM> may be matched a padding layer composed of materials measured at approximately <NUM> Shore A; an almost flat-toothed profile <NUM> may be matched a padding layer composed of materials measured at approximately <NUM> Shore D. Thus, the types of padding blocks (i.e., the hardness measurement of the padding layer) can be selected based, in part, on the tooth profile of the blades.

In one embodiment, pad <NUM> may be formed on the working surface of fixed platen <NUM> using a combination of different types of padding blocks <NUM>. This combination of different types of padding blocks may be particularly useful when blades having different profiles are installed on the inner surface of moving platen <NUM> to cut work pieces. Thus, the types of padding blocks may be selected to match the blades used to cut particular regions of the work piece.

Because different types of padding layers may be employed to provide cutting surfaces of different hardness measurements with respect to different types of blades, the soft cut system of the present disclosure may broaden the range of work piece materials that can be cut and improve the quality of cuts compared to the current steel-to-steel die cut systems. The soft cut system allows a new range of work piece materials to be cut, including, for example, foam boards and structural paper panels. These materials were traditionally cut by the slow process of plotter tables rather than clamshell die presses. The soft cut system as described in this disclosure may improve the productivity (up to <NUM> times) over the traditional process using plotter tables.

The interchangeable padding blocks <NUM> of the soft cut system can also reduce wears on the blades and allow blades of a wider range of tooth profiles to be used because the blades can now cut into the soft surface of the padding layers of the padding blocks. Because the blade cuts into a softer padding layer and does not scratch a cutting surface that is at least as hard as the blade, the wears to the blade is significantly reduced. As such, the useful lives of blades used in the context of the soft cut system can be prolonged, thus reducing the cost for die cut. Further, by cutting against the soft padding layer rather than scratching the hard cutting surface of the fixed platen, the blades do not generate the hazardous noise level while cutting work pieces. The soft cut system further allows for a shear cut motion. The shear cut requires less tonnage for cutting through. The soft cut system can control the depth of the tooth profile cutting into the padding layer to enable precision cuts.

The soft cut system also allows die cutting of multiple layers of work pieces. To cut multiple layers of work pieces, die press may need to increase the tonnage of pressing force applied by the moving platen. The higher tonnage of pressing force may cause damage to the blades when they strike the hard surface of the fixed platen. Thus, the steel-to-steel die cut typically allows die cutting of only a single layer of work piece. In contrast, blades of the die press including the soft cut system as described in the present disclosure cut into the soft material of the padding layer, thus permitting the higher force used in multiple-layer die cutting. For example, the soft cut system can be used to cut up to ten layers of a graphic decal in one press cycle as opposed to only one layer per cycle. Thus, the soft cut system may significantly increase the productivity of clamshell die presses.

In one embodiment, a creasing matrix may be mounted on top of the pad <NUM>. The creasing matrix is a hardware module including channels which a die tooling may press against to create creases on (rather than cutting through) the work pieces. <FIG> shows a creasing matrix <NUM> used in conjunction with the soft cut system according to an embodiment of the present disclosure. Creasing matrix <NUM> can be made of composition materials such as, for example, an extruded polymer or vulcanized fiberboard. As shown in <FIG>, creasing matrix <NUM> may include a channel <NUM>. A creasing tooling, such as a blunt tooling <NUM> may press against a work piece into channel <NUM> to create creases in the work piece. In one embodiment, a pad <NUM> may be bonded to a fixed platen <NUM> of a die press using magnetic force, and creasing matrix <NUM> may be adhesively attached on to the top surface of pad <NUM>.

<FIG> illustrates an exemplary process <NUM> for using the soft cut system in die press according to an embodiment of the present disclosure. As discussed above, a die press may be a clamshell die press including a fixed platen and a moving platen. At <NUM>, the material of a work piece to be cut may be determined. The material of the work piece may be cardboard, plastic sheet, corrugated board, foam board, structural paper panels etc. In addition to determining the material of the work piece, certain physical properties of the work piece, such as the thickness and dimensions of the work piece, can be determined.

At <NUM>, in response to determining properties of the work piece, die cut blades of certain tooth profile may be selected based on these properties of the work piece. The tooth profile may be selected based on the material of the work piece and depth that needs to be cut.

At <NUM>, in response to determining properties of the work piece and selecting the die cut blades, the padding blocks may be selected to match the properties of the work piece and the tooth profile of the die cut blades. The padding blocks may be selected to enable an optimal match between the hardness of the padding layer and the tooth profile of the cutting blades.

At <NUM>, in response to selecting the padding blocks, the selected padding blocks may be secured to the fixed platen. In one embodiment, the selected padding blocks may be secured to the fixed platen using a magnetic layer (e.g., a double-sided magnetic mat) to enable the bonding of padding blocks to the fixed platen. In one embodiment, rather than covering the whole surface of the fixed platen, the pad including the selected padding blocks covers only portions of the whole surface. For example, the pad may cover certain areas that receive the cutting blades during the die cut. After installation of the pad on the fixed platen and installation of the tooling including the cut blades, an operator may start operating the die press to cut work pieces.

The words "example" or "exemplary" are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "example' or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the words "example" or "exemplary" is intended to present concepts in a concrete fashion. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X includes A or B" is intended to mean any of the natural inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then "X includes A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Moreover, use of the term "an embodiment" or "an embodiment" or "an implementation" or "one implementation" throughout is not intended to mean the same embodiment or implementation unless described as such.

Reference throughout this specification to "an embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an embodiment. Thus, the appearance of the phrases "in an embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment.

Claim 1:
A pad set (<NUM>) comprising padding blocks (<NUM>) for reconfigurably mounting on a flat working surface of a clamshell die press device (<NUM>) to provide a cushion for die cutting, wherein the pad set (<NUM>) comprises:
a first padding block (<NUM>) comprising a backing layer (<NUM>) and a first padding layer (<NUM>) that is bonded to the backing layer (<NUM>), wherein the backing layer is composed of a metal and the first padding layer (<NUM>) is composed of a first padding material having a first Shore value; and
a second padding block (<NUM>) comprising a second backing layer (<NUM>) and a second padding layer that is bonded to the second backing layer, wherein the second backing layer is composed of the metal and the second padding layer (<NUM>) is composed of a second padding material having a second Shore value, wherein the first Shore value is different than the second Shore value, one of the first padding block or the second padding block is to be mounted on a working surface of the clamshell die press device, the first padding block is paired with a first cutting blade (<NUM>) having a first tooth profile, and the second padding block is paired with a second cutting blade (<NUM>) having a second tooth profile, and the first and second Shore values represent a respective hardness measurement of the corresponding first and second padding materials, wherein a padding block is selected based on a determination that a hardness parameter of padding material of its padding layer matches a tooth profile of a cutting blade (<NUM>) installed on the clamshell die press device (<NUM>).