The present invention relates to metal forming dies and the like, and in particular to a stock ejector assembly and associated method incorporating a unique stock ejector assembly.
Metal forming dies, such as stamping dies and the like, are well known in the art.
Progressive metal forming dies are unique, very sophisticated mechanisms which have multiple stations or progressions that are aligned longitudinally, and are designed to perform a specified operation at each station in a predetermined sequence to create a finished metal part. Progressive stamping dies are capable of forming complex metal parts at very high speeds, so as to minimize manufacturing costs.
Heretofore, the dies used in metal forming presses have typically been individually designed, one-of-a-kind assemblies for a particular part, with each of the various components being handcrafted and custom mounted or fitted in an associated die set, which is in turn positioned in a stamping press. Not only are the punches and the other forming tools in the die set individually designed and constructed, but the other parts of the die set, such as stock lifters, guides, end caps and keepers, cam returns, etc., are also custom designed, and installed in the die set. Current die making processes require carefully machined precision holes and recesses in the die set for mounting the individual components, such that the same are quite labor intensive and require substantial lead time to make, test, and set up in a stamping press. Consequently, such metal forming dies are very expensive to design, manufacture, and repair or modify.
A liquid, such as a lubricant, mill oil, or water may be used on the stock and one or more of the die parts to decrease the wear on the die parts and/or damage to the stock. When a liquid is used on the stock or upper and/or lower die parts of a metal forming die, the stock has a tendency to stick to the die parts. Thus, something must be done to break the lubricant tension/adhesion on the stock so that it can be removed from that portion of the die. In addition, tension/adhesion can also exist between the stock and flat surfaces on the dies whether or not a liquid is used with the stock and/or dies. Such adhesion between flat surfaces also requires the breaking of the developed tension. One way of breaking the tension is to use a threaded spring plunger. This is a self-contained assembly that includes a very small diameter spring which is prone to fail quickly due to its size. When the threaded spring plunger fails, it is a hassle for stampers as they have to continuously replace the threaded spring plungers. Another problem is that the threaded spring plungers typically have a pointed tip that can leave a mark on the stock if the spring pressure is too great.
Another example of the prior art includes ejector pin assemblies 148, as shown in
The need for an improved stock ejector thus stems from the issues that metal stamping producers and die shops have long had when creating an “oil breaker” setup in their dies. The improved stock ejector addresses two main items that are currently problematic: The first is that it utilizes a large spring, which provides a much longer product life than a traditional spring plunger. The large spring is on the “exterior” of the assembly and the other construction methods are internal. This design provides the ability for a large spring to be used while keeping the overall footprint of the assembly as small as possible. The second is the increase in surface area that makes contact with the stock. Typical plunger “point” style on spring plungers have very little surface area, and most commonly used are the points that are rounded/spherical. This provides very little contact with the stock and it can leave a “mark” if the spring pressure compared to the contact surface area on the stock are not proper. The improved stock ejector utilizes a “ring” style stripper, which provides more overall surface area in contact with the stock. This amount of contact surface area prevents the stock from being “marked” but is also not so high that the stock wants to stick to it.
Thus, a product that solves these problems would be advantageous and is described herein.
One aspect of the present invention is a stock ejector assembly that utilizes a large spring, thereby providing a longer product life. The spring is on the “exterior” of the assembly, allowing for a large spring to be used while keeping the overall footprint of the assembly as small as possible. Another aspect of the present invention is to provide a stock ejector assembly that has an increased surface area that makes contact with the stock. Thus, the present invention includes a “ring” style stripper which provides a larger surface area to contact the stock. The increased contact surface area prevents the stock from being “marked” and prevents the stock from sticking to the ejector.
Yet another aspect of the present invention is a multi-station progressive metal forming die having at least two, mutually converging and diverging die members between which an elongate stock strip is shifted longitudinally to form parts from the stock strip, along with an improved stock ejector assembly. The stock ejector assembly includes a stock ejector body with an outer end portion oriented toward the stock strip, an inner end portion oriented away from the stock strip, and a medial portion between the outer end portion and the inner end portion. The outer end portion of the stock ejector body includes a shoulder with an outer end surface and an inner end surface. The inner end portion of the stock ejector body includes a threaded shank portion that secures the assembly to one of the die members. The medial portion of stock ejector assembly includes a shoulder with an outer end surface and an inner end surface. The stock ejector assembly includes a stripper with an outer end portion arranged toward the stock strip and an inner end portion oriented away from the stock strip. The outer end portion of the stripper includes an aperture with a first diameter, and the inner end portion includes an aperture with a second diameter. The second diameter is less than the first diameter of the outer end portion, forming a generally annular shoulder that engages the inner end surface of the shoulder of the outer end portion of the stock ejector body. The stock ejector assembly includes a spring member having a generally hollow interior that is received over the stock ejector body, an outer end oriented toward the stock strip that engages the inner end portion of the stripper, and an opposite inner end oriented away from the stock strip that engages the outer end surface of the shoulder of the medial portion of the stock ejector body. The stock ejector assembly optionally includes a spacer having a generally hollow interior that is received over a portion of the threaded shank portion of the inner end portion of the stock ejector body. The space has an outer end surface oriented toward the stock strip that engages the inner end surface of the shoulder of the medial portion of the stock ejector body, and an inner end surface oriented away from the stock strip.
Yet another aspect of the present invention is a stock ejector assembly for metal forming dies that have least two mutually converging and diverging die members to form parts from the stock strip. The stock ejector assembly includes a stock ejector body with an outer end portion oriented toward the stock strip, an inner end portion oriented away from the stock strip, and a medial portion between the outer end portion and the inner end portion. The outer end portion of the stock ejector body includes a shoulder with an outer end surface and an inner end surface. The inner end portion of the stock ejector body includes a threaded shank portion that secures the assembly to one of the die members. The medial portion of stock ejector assembly includes a shoulder with an outer end surface and an inner end surface. The stock ejector assembly includes a stripper with an outer end portion arranged toward the stock strip and an inner end portion oriented away from the stock strip. The outer end portion of the stripper includes an aperture with a first diameter, and the inner end portion includes an aperture with a second diameter. The second diameter is less than the first diameter of the outer end portion, forming a generally annular shoulder that engages the inner end surface of the shoulder of the outer end portion of the stock ejector body. The stock ejector assembly includes a spring member having a generally hollow interior that is received over the stock ejector body, an outer end oriented toward the stock strip that engages the inner end portion of the stripper, and an opposite inner end oriented away from the stock strip that engages the outer end surface of the shoulder of the medial portion of the stock ejector body. The stock ejector assembly optionally includes a spacer having a generally hollow interior that is received over a portion of the threaded shank portion of the inner end portion of the stock ejector body. The space has an outer end surface oriented toward the stock strip that engages the inner end surface of the shoulder of the medial portion of the stock ejector body, and an inner end surface oriented away from the stock strip.
Yet another aspect of the present invention is a method for making a multi-station progressive metal forming die having at least two mutually converging and diverging die members between which an elongate stock strip is shifted longitudinally to form parts from the stock strip, with the improvement of at least one stock ejector assembly. The method includes forming a stock ejector body with an outer end portion oriented toward the stock strip, an inner end portion oriented away from the stock strip, and a medial portion between the outer end portion and the inner end portion. The method includes forming said outer end portion of the stock ejector body to have a shoulder with an outer end surface and an inner end surface. The method includes forming said inner end portion of the stock ejector body to have a threaded shank portion that secures the assembly to one of the die members. The method includes forming the medial portion of the stock ejector body to have a shoulder with an outer end surface and an inner end surface. The method includes forming a stripper with an outer end portion arranged toward the stock strip and an inner end portion oriented away from the stock strip. The method includes forming the outer end portion to include an aperture with a first diameter and forming said inner end portion to include an aperture with a second diameter. The second diameter of the inner end portion is less than the first diameter of the outer end portion, forming a generally annular shoulder that engages the inner end surface of the shoulder of the outer end portion of the stock ejector body. The method includes selecting a spring member with a generally hollow interior, an outer end oriented toward the stock strip, and an opposite inner end oriented away from the stock strip. The method includes inserting the spring member over the outer end portion of the stock ejector body with the inner end of the spring member engaging the outer end surface of the shoulder of the medial portion of the stock ejector body. The method includes inserting the stripper over the outer end portion of the stock ejector body. The method includes inserting a tool into the stripper and moving the tool toward the inner end portion of the stock ejector body, thereby compressing the stock ejector assembly such that the inner end portion of the stripper moves past the shoulder of the outer end portion of the stock ejector body. The method includes removing the tool to permit the spring to push the stripper toward the outer end of the stock ejector body, allowing the annular shoulder of the stripper to engage the inner end surface of the shoulder of the outer end portion of the stock ejector body. The method optionally includes selecting a spacer that is placed over a portion of the inner end portion of the stock ejector body. The method includes securing the stock ejector assembly to one die member.
These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written description, claims, and appended drawings.
For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in the attached drawings. However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in
The reference numeral 2 (
The stock ejector assembly 2 includes a stock ejector body 4, a stripper 8, a fastener 54, and optionally a spacer 10, as shown in
The stock ejector body 4 includes an outer end portion 82, oriented toward the stock strip 30, an inner end portion 80, and a medial portion 84, as shown in
The stripper 8 has an outer end portion 20 oriented toward the stock strip 30, an oppositely disposed inner end portion 22 oriented away from the stock strip 30 with a hollow interior 21 extending therebetween. The outer end portion 20 of the stripper 8 is generally ring-shaped, as shown in
As illustrated in
The spring member 32 includes a hollow interior 34, as shown in
The stock ejector assembly 2 also includes an optional space 10 with an outer end surface 14 and an inner end surface 16. The spacer 10 has a hollow interior 15 that is received over the threaded shank 92 of the stock ejector body 4 when the stock ejector assembly 2 is completed.
As best illustrated in
When the stock ejector assembly 2 is fully assembled, the spring member 32 is preloaded, as shown by the arrows P in
The stock ejector assembly 2 can be assembled to one of the die members 72, 74 of the metal forming die 70. As illustrated in
As illustrated in
The stock strip 30 is received between the die members 72 and 74 when the die members 72, 74, converge, as illustrated in
The term “die member” as used herein refers to any portion of a metal forming die or die set, including, but not limited to, an upper die member or a die shoe, a lower die member or a die shoe, and other die components, whether stationary or reciprocating, including a reciprocating pressure pad, and the like. In the illustrated examples, the stock ejector assembly 2 can be mounted in any die member. The stock ejector assembly 2 can be mounted in other types of die members and/or components and in a variety of different positions and orientations, as will be appreciated by those skilled in the art. In addition, the stock ejector assembly 2 can be used in a single stage die assembly.
Stock ejector assembly 2 has an uncomplicated construction with relatively few components and is therefore quite durable and economical to manufacture. Multiple components of the stock ejector assembly 2 may be formed from a single piece of rigid material. For example, the stripper 8, stock ejector body 2, and optional spacer 10 may have a one-piece construction made from a solid bar of material, such as steel. The fasteners and optional window mount 46 attachment of the stock ejector assembly 2 to an associated die members 72, 74 provides quick and easy installation and removal of the stock ejector assembly 2. The spring member 32 and the stock ejector assembly 2 are backed up or axially supported by the die member itself for greater strength and convenience. Stock ejector assembly 2 positively separates the stock strip from the die during operation of the metal forming die, and provides a very compact, low-profile shape that can be used at various locations and orientations on various die members. The installation of the stock ejector assembly 2 can be achieved with simple machining so as to reduce the installation time and cost. The shape of the stock ejector assembly 2 can be configured so as to accommodate many different applications and users.
In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.
Applicants hereby claim the priority benefits under the provisions of 35 U.S.C. §119, basing said claim of priority on related U.S. Provisional Application No. 62/075,966 filed Nov. 6, 2014.
Number | Name | Date | Kind |
---|---|---|---|
2168377 | Wales | Aug 1939 | A |
3335627 | Smelts | Aug 1967 | A |
3998369 | Grosjean et al. | Dec 1976 | A |
4342214 | Neuendorf | Aug 1982 | A |
4424639 | Richardson | Jan 1984 | A |
4644836 | Wepner | Feb 1987 | A |
4916931 | Kaeseler | Apr 1990 | A |
4945749 | Walker et al. | Aug 1990 | A |
5722280 | Bodnar | Mar 1998 | A |
5860315 | Sawdon | Jan 1999 | A |
7694399 | Sawdon et al. | Apr 2010 | B2 |
7913369 | Gakovic | Mar 2011 | B2 |
8151619 | Pyper et al. | Apr 2012 | B2 |
20060193937 | Gakovic | Aug 2006 | A1 |
20090044671 | Greenleaf | Feb 2009 | A1 |
20090193865 | Pyper et al. | Aug 2009 | A1 |
20140144202 | Pyper et al. | May 2014 | A1 |
Number | Date | Country |
---|---|---|
56084130 | Sep 1981 | JP |
56122634 | Sep 1981 | JP |
57100825 | Jun 1982 | JP |
06142788 | May 1994 | JP |
1020010069897 | Jul 2001 | KR |
1020060104028 | Oct 2006 | KR |
100766072 | Oct 2007 | KR |
604608 | Apr 1978 | SU |
1065064 | Jul 1984 | SU |
Entry |
---|
Standard Lifters Inc., “Pilot Assembly” sales brochure, Grand Rapids, MI (Oct. 2011), 15 pages. |
Standard Lifters Inc., “Pilot Sleeve” sales brochure, Grand Rapids, MI (Jan. 2012), 18 pages. |
Fibro Inc., “Pilot Units to Daimler Standards” catalog p. E72, Rockford, IL (date unknown). |
Dayton Progress Corporation, “Regular Pilots” catalog, pp. 9, 11, 13, Dayton, OH (date unknown). |
Ajacs Die Sales Corporation, Pilot Retainer sales brochure, Grand Rapids, MI (date unknown). |
Misumi Corporation, “Pilot Punches” catalog, pp. 202, 220, 228, 234, 242, 946, 948, Schaumberg, IL (date unknown). |
Modern Die Systems Inc., “Die Accessories” sales brochure, Ellwood IN (date unknown), 1 page. |
Number | Date | Country | |
---|---|---|---|
20160129493 A1 | May 2016 | US |
Number | Date | Country | |
---|---|---|---|
62075966 | Nov 2014 | US |