Patent Application
20110174131
The present teachings relates generally to retaining boards and more particularly to locks for holding steel rule dies of varying widths within a die cutting die slot of a retaining board.
Steel rule dies are widely used to cut a variety of materials such as cardboard and plastics into a desired shape. Often, the steel rule dies are pressure inserted into slots located in a board of wood or other suitable material. During operation of the cutter, these dies often become loosened and ultimately disengaged, thereby necessitating costly and time consuming interruption of the cutting process as repairs are undertaken. In addition, the slots are of varying widths to accommodate dies of varying widths, thus making standardization difficult.
Several attempts have been made to prevent this loosening of the steel rule dies. For example, U.S. Pat. No. 4,052,886 discloses a solid base material having caverns which are filled with semi-rigid filler material to anchor an inserted steel die. However, this method requires time-consuming filling and the ultimate strength of securing is dependant on the filler material selected. U.S. Pat. No. 3,941,038 discloses the use of S-wall shaped resilient members which pin the rule between itself and packing shims. This apparatus necessitates a difficult insertion of the rule between the resilient member and shims. A third proposal is shown in U.S. Pat. No. 3,835,746. A resilient support and spring are deformed upon insertion of the die and thereafter exert an upward force against the die to secure it in a slot. Such a deformation ultimately leads to mechanical failure of the retaining system as the dies are continuously replaced.
U.S. Pat. No. 5,029,505 discloses an apparatus for improved retention of steel rule dies inserted into slots of a retaining board. A plurality of housings, each having a spring and ball assembly, are inserted into chambers of a retaining board. The balls bias a steel rule die in an associated slot such that the rule is securely, yet removably, held in the slot. Manufacturing the spring and ball assembly inside the housing can be a complicated task.
It is an object of the present teachings to provide a devise for securely retaining a die cutting die in a retaining board.
It is a further object of the present teachings to accomplish the foregoing object without difficult insertion of the device or the die cutting die.
It is yet another object of the present teachings to accomplish the preceding objects simply and economically.
It is a still further object of the present teachings to achieve the foregoing objects with an apparatus that is durable and long lasting.
It is another object of the present teachings to achieve the above objects for die cutting dies of varying widths.
Other objects and advantages will be apparent from the specification and drawings which follow.
The foregoing and additional objects are obtained by a device and system according to the present teachings, for securing a die cutting die, for example, a steel rule die, in an associated die slot in a retaining board. The retaining board can comprise at least one narrow chamber located adjacent to each die slot, having an open face that opens toward the die slot. The chamber can be oriented substantially perpendicularly relative to the direction of insertion of the die. A securing device, also referred to herein as a kerf lock, is provided for urging an inserted die cutting die normally towards an opposite wall of the die slot is located opposite the open face of the chamber and is positioned within the chamber. Accordingly, a die cutting die inserted in the die slot is securely held within the slot.
According to various embodiments, the securing device can comprise a generally rectanguloid member having a central through slot. The central through slot can comprise a top end having a first width, a bottom end having a second width, a widened through hole intersecting the top end and having a first minimum dimension, and a widened through hole intersecting the bottom end and having a second minimum dimension. The first minimum dimension can be larger than the first width and the second minimum dimension can be larger than the second width. The central through slot can have a maximum width in a middle portion thereof, and the maximum width can be the same as or greater than each of the first and second minimum dimensions when the securing device is not in use.
Although the phrase “die cutting die” is used oftentimes herein, it is to be understood that the dies referred to also include creasing dies, scoring dies, perforating dies, and the like. The dies can be of any material, for example, steel rule dies, aluminum dies, titanium dies, and the like.
The present teachings will be more fully understood with reference to the appended drawings which are intended to illustrate, not limit, the present teachings.
According to various embodiments, a system and device are provided to secure a die cutting die in a die slot of a retaining board. The securing device comprises a generally rectanguloid member having a central through slot. The central through slot can comprise a top end having a first width, a bottom end having a second width, a widened through hole intersecting the top end and having a first minimum dimension, and a widened through hole intersecting the bottom end and having a second minimum dimension. The first minimum dimension can be larger than the first width and the second minimum dimension can be larger than the second width. The central through slot can have a maximum width in a middle portion thereof, and the maximum width can be the same as or greater than each of the first and second minimum dimensions when the securing device is not in use.
In some embodiments, the generally rectanguloid member is 0-shaped or -shaped and comprises rounded top edges and rounded bottom edges. The securing device can be of one-piece, unitary construction. The securing device can comprise a plastic material, a polyalkylene material, a polytetrafluoroethylene material, a polyoxymethylene material, a polyacetal material, a polyformaldehyde material, a phenolic resin material, a combination thereof, or the like. In some embodiments, the securing device comprises a polytetrafluoroethylene material. In some embodiments, the securing device comprises a polyoxymethylene material.
The device can have a first resilient arm on one side of the central through slot, and a second resilient arm on an opposite side of the central through slot, wherein both the first resilient arm and the second resilient arm are configured to move toward one another as the generally rectanguloid member is compressed laterally, for example, when in use. The central through slot can have a longitudinal middle and a width that increases from the top end to the middle. In some embodiments, as is shown in
The generally rectanguloid member can comprise a top face and an opposite bottom face, and one or both of the top face and the bottom face can have tapered edges. The through holes that intersect the central through slot can be circular cross-section, and the first minimum dimension and the second minimum dimension can be diameters. The central through slot can have a maximum width that is greater than the first minimum dimension and greater than the second minimum dimension. In some embodiments, the central through slot has a maximum width that is the same as the first minimum dimension and the same as the second minimum dimension.
According to yet other embodiments of the present teachings, a system is provided that comprises a retaining board, a die cutting die, and a securing device as described herein. The retaining board can have formed therein an elongated die slot having opposite sides, and a lock slot intersecting the elongated die slot. The die cutting die can be disposed within the die slot, and the securing device can be disposed within the lock slot and in contact with the die cutting die. In some embodiments, the retaining board has first and second opposing faces, the securing device has an upper surface and a lower surface, the upper surface is spaced from the first opposing surface, and the lower surface is spaced from the second opposing surface.
In some embodiments, the system can comprise a plurality of securing devices and the retaining board can have formed therein a plurality of lock slots each intersecting the elongated die slot. The plurality of securing devices can be respectively disposed within the plurality of lock slots and in contact with the die cutting die.
The present teachings will now be described in greater detail with reference to the accompanying drawings. Referring to
To prevent an inserted steel rule dies 3 from loosening within die slots 2, a plurality of kerf locks 4 according to the present teachings, are provided. Each kerf lock 4 can be positioned within a respective lock slot 5, adjacent a corresponding die slot 2. Lock slots 5 are in communication with die slots 2 via an open face. As will be apparent to one skilled in the art from the present application, the number and locations of the kerf locks and associated lock slots are determined by considering such factors as optimum securing of the inserted dies, configuration of the die cutting die, and manufacturing costs.
The securing device or kerf lock is preferably of a unitary construction and can be easily injection molded. The kerf lock can comprise two arms connected by a top bridge at one end and connected by a bottom bridge at the other end. The kerf lock is generally zero-shaped (0-shaped) or rectangularly-shaped (-shaped).
When the kerf lock is disposed within a lock slot of the retaining board, one arm rests against the retaining board while the other arm has a force transmitting surface face which extends into the die slot. Both arms can be resilient and elastic. When a die cutting die is inserted into the die slot, the force transmitting arm is forced in a direction toward the resting or support arm. This creates a spring-type force such that the force transmitting surface of the force transmitting arm exerts a pressure against the die cutting die which secures the die cutting die in the die slot. While a sufficient pressure is applied to hold the die cutting die, the rule may be pulled out of the die slot with a pair of pliers, for example, a pair of Channel Lock® pliers. No disassembly of the lock or retaining board is necessary to pull out the die cutting die. The number of kerf locks can be varied to supply greater or lesser pressure to hold the die cutting die in the die slot.
The kerf lock may be manufactured by various methods which may include stamping or injection molding. The kerf lock preferably comprises a plastic. In some embodiments, the kerf lock is injection molded of polytetrafluoroethylene or polyoxymethylene, which provide a rigid, long lasting article that does not lose its elasticity over its lifetime.
As best seen in
Both 8 and 10 can have the same height and the same thickness. The entire height of the kerf lock can be about 50 to 75 percent more than the height of arms 8 and 10 alone, with the added height being attributed to the heights of bridges 12 and 14. For example, kerf lock 4 can be defined by a length of from about 0.400 inch to about 0.800 inch, for example, 0.615 inch, a width of from about 0.200 inch to about 0.500 inch, for example, 0.284 inch, and a height from about 0.090 inch to about 0.150 inch, for example, 0.115 inch.
Arms 8 and 10 are separated normally by a central through slot 16 which has a width that increases from its ends toward its middle, as shown in
To provide a rigid yet resilient kerf lock having an even stress distribution when in use, arms 8 and 10 and bridges 12 and 14 intersect with one another and the kerf lock has smooth curves at the corners thereof, such as rounded corners 22 and 24 shown in
To facilitate the insertion of the die cutting die into a die slot of a retaining board according to the present teachings, a smoothly curved surface is provided on the kerf lock at the top bridge where initial contact is made with the die cutting die. The curved surface is continuous with the force transmitting surface of whichever arm extends into the die slot. The curved surface preferably has a radius of curvature which is from about 0.025 to about 0.050 inch.
To facilitate insertion of the kerf lock into a lock slot of a retaining board, top surface 26 of the kerf lock has smooth curved surfaces comprising rounded corners and a tapered edge 28. For example, tapered edge 28 can be defined by a radius of curvature of, for example, from about 0.010 inch to about 0.030 inch, or 0.016 inch. Bottom face 30 of kerf lock 4 can have tapered edges, such as those along top surface 26, but as shown in
The present teachings thus prevents down time associated with loose dies. The device and system securely hold die cutting dies in a simple, efficient, and economic manner. Also, the kerf lock is very durable and can secure dies of different widths in differently sized die slots.
Other embodiments will be apparent to those skilled in the art from consideration of the present specification and practice of various embodiments disclosed herein. It is intended that the present specification and examples be considered as exemplary only.
The present application claims a priority benefit from U.S. Provisional Patent Application No. 61/296,600, filed Jan. 20, 2010, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61296600 | Jan 2010 | US |
