The present invention relates to metal forming dies and the like, and in particular to a guide pin assembly and associated method.
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.
Recently, some components for metal forming dies have been pre-constructed using a modular design that is installed in a die set as a complete unit, instead of custom making each of the component parts and assembling them in the die set. One such modular die component is Applicant's “Guided Keeper,” which is the subject of U.S. Pat. Nos. 7,950,262, 8,074,486, and others, which are hereby incorporated herein by reference, and has met with substantial commercial success in reducing the overall cost of manufacturing metal forming dies. While such modular components are very advantageous, further improvements to reduce the manufacturing costs of metal forming dies generally, as well as such modular components, and improve quality and strength would clearly be advantageous. Hence, a guide pin assembly construction and associated method which simplifies the manufacturing process, reduces lead time and inventories, and minimize manufacturing costs, as well as improved performance, would clearly be advantageous.
One aspect of the present invention is a guide pin assembly for metal forming dies having first and second die members which mutually converge and diverge to form metal parts. The guide pin assembly includes a guide pin body having a generally cylindrical shape, with a predetermined outside diameter. The guide pin body includes a first end portion configured for secure operable attachment with the first die member, a second end portion disposed generally opposite the first end portion, and configured to be received into an associated aperture in the second die member, a medial portion disposed between the first and second end portion, and having a generally hard, smooth, finished exterior surface for precisely guiding converging and diverging motion between the first and second die members, and a first retainer groove extending circumferentially about the exterior surface at an axial location disposed generally adjacent to the second end portion of the guide pin body, and having a generally arcuate shape that opens radially outward. The guide pin assembly also includes a guide pin head ring having a generally annular plan configuration, a generally cylindrically shaped exterior sidewall with a predetermined outside diameter that is greater than the outside diameter of the guide pin body, a generally circularly shaped interior sidewall with a predetermined inside diameter that is generally commensurate with the outside diameter of the guide pin body, a generally annularly shaped outwardly facing end edge, and a generally annularly shaped inwardly facing end edge. The guide pin head ring also includes a second retainer groove extending circumferentially about a medial portion of the interior sidewall, and has a generally arcuate shape that opens radially inwardly, and is generally axially aligned with the first retainer groove in the guide pin body when the guide pin assembly is in an assembled condition. The guide pin head ring also includes a counterbore formed into the outwardly facing end edge of the guide pin head ring, recessed into the interior sidewall of the guide pin head ring and extending generally axially from the outwardly facing end edge to the second retainer groove, and defines a counterbore wall. The guide pin assembly also includes a retainer ring having a radially inward portion thereof closely received and retained in the first retainer groove in the guide pin body, and a radially outward portion protruding radially outwardly from the exterior surface of the guide pin body and being closely received and retained in the second retainer groove in the guide pin head ring to fixedly axially mount the guide pin head ring on the second end portion of the guide pin body and define an enlarged head portion of the guide pin assembly that serves to positively limit travel between the first and second die members. The guide pin head assembly also includes a guide pin head cap having a generally circular plan configuration, an outwardly oriented exterior face, an inwardly oriented interior face, and a generally annularly shaped support collar protruding axially inwardly from the interior face of the guide pin head cap, with a radially interior sidewall defining a socket in which the second end portion of the guide pin body is received, and a radially exterior sidewall which is closely received against the counterbore wall, such that the support collar is retained in the counterbore in the guide pin head ring and captures the retainer ring in the first retainer groove in the guide pin body and the second retainer groove in the guide pin head cap, such that the guide pin head ring is securely supported on the second end portion of the guide pin body to withstand impact forces applied to the enlarged head portion of the guide pin assembly during repeated, mutual convergence and divergence of the first and second die members.
Yet another aspect of the present invention is a metal forming die having first and second die members which mutually converge and diverge to form metal parts in combination with an improved guide pin assembly. The guide pin assembly includes a guide pin body having a generally cylindrical shape, with a predetermined outside diameter, a first end portion operably attached to the first die member, a second end portion disposed generally opposite the first end portion, and received in an associated aperture in the second die member, a medial portion disposed between the first and second end portions, and having a generally hard, smooth finished exterior surface for precisely guiding the converging and diverging motion between the first and second die members, and a first retainer groove extending circumferentially about the exterior surface at an axial location disposed generally adjacent to the second end portion of the guide pin body, and having a generally arcuate shape that opens radially outward. The guide pin assembly also includes a guide pin head ring having a generally annular plan configuration, a generally cylindrically shaped exterior sidewall with a predetermined outside diameter that is greater than the predetermined outside diameter of the guide pin body, a generally cylindrically shaped interior sidewall with a predetermined inside diameter that is generally commensurate with the predetermined outside diameter of the guide pin body, a generally annularly shaped outwardly facing end edge, and a generally annularly shaped inwardly facing end edge. The guide pin head ring also includes a second retainer groove extending circumferentially about a medial portion of the interior sidewall, and having a generally arcuate shape that opens radially inwardly, and is generally axially aligned with the first retainer groove in the guide pin body when the guide pin assembly is in an assembled condition. The guide pin head ring further includes a counterbore formed into the outwardly facing end edge of the guide pin head ring, recessed into the interior sidewall of the guide pin head ring and extending generally axially from the outwardly facing end edge to the second retainer groove, and defining a counterbore wall. The guide pin assembly further includes a retainer ring having a radially inward portion thereof closely received and retained in the first retainer groove in the guide pin body, and a radially outward portion thereof, protruding radially outwardly from the exterior surface of the guide pin body and being closely received and retained in the second retainer groove in the guide pin head ring to fixedly axially mount the guide pin head ring on the second end portion of the guide pin body and define an enlarged head portion of the guide pin assembly that serves to positively limit travel between the first and second die members. The guide pin assembly also includes a guide pin head cap having a generally circular plan configuration, an outwardly oriented exterior face, an inwardly oriented interior face, and a generally annularly shaped support collar protruding axially inwardly from the interior face of the guide pin head cap, with a radially interior sidewall defining a socket in which the second end portion of the guide pin body is received, and a radially exterior sidewall which is closely received against the counterbore wall, such that the support collar is retained in the counterbore in the guide pin head ring, and captures the retainer ring in the first retainer groove in the guide pin body and the second retainer groove in the guide pin head cap, such that the guide pin head ring is securely supported on the second end of the guide pin assembly during repeated, mutual convergence and divergence of the first and second die members.
Yet another aspect of the present invention is a method for making a guide pin assembly for metal forming dies of the type having first and second die members which mutually converge and diverge to form metal parts. The method comprises forming a guide pin body with a generally cylindrical shape, a predetermined outside diameter, a first end portion configured for secure operable attachment with the first die member, a second end portion disposed generally opposite the first end portion and configured to be received into an associated aperture in the second die member, and a medial portion disposed between the first and second end portions, and having a generally hard, smooth finished exterior surface for precisely guiding a converging and diverging motion between the first and second die members. The method further includes forming a first retainer groove in the guide pin body, extending circumferentially about the exterior surface thereof at a location disposed generally adjacent to the second end portion of the guide pin body with a generally arcuate shape that opens radially outwardly. The method further includes forming a guide pin head ring with a generally annular plan configuration, a generally circularly shaped exterior sidewall having a predetermined outside diameter that is greater than the predetermined outside diameter of the guide pin body, a generally cylindrically shaped interior sidewall with a predetermined inside diameter that is generally commensurate with the predetermined outside diameter of the guide pin body, a generally annularly shaped outwardly facing end edge, and a generally annularly shaped inwardly facing end edge. The method further includes forming a second retainer groove in the guide pin head ring extending circumferentially about a medial portion of the interior sidewall with a generally arcuate shape that opens radially inwardly, and is generally axially aligned with the first retainer groove in the guide pin body when the guide pin assembly is in an assembled condition. The method further includes forming a counterbore into the outwardly facing end edge of the guide pin head ring that is recessed into the interior sidewall of the guide pin head ring, extends generally axially from the outwardly facing end edge to the second retainer groove, and defines a counterbore wall. The method further includes providing a retainer ring having a radially inward portion shaped for close reception in the first retainer groove in the guide pin body, and a radially outward portion shaped for close reception in the second retainer groove in the guide pin head ring. The method further includes forming a guide pin head cap with a generally circular plan configuration, an outwardly oriented exterior face, an inwardly oriented interior face, and a generally annularly shaped support collar protruding axially inwardly from the interior face of the guide pin head cap and having a free end edge, having a radially interior sidewall defining a socket shape to closely receive therein the second end portion of the guide pin body, and a radially exterior sidewall shaped to be closely received against the counterbore wall. The method further includes positioning the radially inward portion of the retainer ring in the first retainer ring groove in the guide pin body, and sliding the guide pin head ring onto and over the guide pin body from the first end portion thereof until the guide pin head ring contacts at least a portion of the retainer ring mounted in the first retainer groove on the guide pin body. The method further includes positioning the guide pin head cap over the outwardly facing end edge of the guide pin head ring with at least a portion of the second end portion of the guide pin body received in the socket in the guide pin head cap, at least a portion of the support collar of the guide pin head cap received in the counterbore in the guide pin head ring. The method further includes converging the guide pin head cap and the guide pin head ring until at least a portion of the free end edge of the support ring on the guide pin head cap contacts at least a portion of the retainer ring mounted in the first retainer groove on the guide pin body. The method further includes pressing the guide pin head cap and the guide pin head ring together, causing engagement of the free end edge of the support ring against the retainer ring mounted in the first retainer groove on the guide pin body, thereby shifting the radially outward portion of the retainer ring into the second retainer groove in the guide pin head ring to fixedly axially mount the guide pin head ring on the second end portion of the guide pin body and define an enlarged head portion of the guide pin assembly that serves to positively limit travel between the first and second die members. The method further includes further pressing the guide pin head cap and the guide pin head ring together until the second end portion of the guide pin body is fully received in the socket in the guide pin head cap, the support collar portion of the guide pin head cap is fully received in the counterbore in the guide pin head ring, and the inwardly oriented interior face of the guide pin head cap abuts with the outwardly facing end edge of the guide pin head ring to positively capture the retainer ring in the first retainer groove in the guide pin body and the second retainer groove in the guide pin head ring, and rigidly supports the guide pin head ring on the second end portion of the guide pin body to withstand impact forces applied to the enlarged head portion of the guide pin assembly during repeated, mutual convergence and divergence of the first and second die members.
Yet another aspect of the present invention is a method for making a metal forming die of the type having first and second die members which mutually converge and diverge to form metal parts. The method includes forming a guide pin body with a generally cylindrical shape, a predetermined outside diameter, a first end portion configured for secure operable attachment with the first die member, and a second end portion disposed generally opposite the first end portion and configured to be received into an associated aperture in the second die member, and a medial portion disposed between the first and second end portions, and having a generally hard, smooth finished exterior surface for precisely guiding the converging and diverging motion between the first and second die members. The method further includes forming a first retainer groove in the guide pin body, which extends circumferentially about the exterior surface at an axial location disposed generally adjacent to the second end portion of the guide pin body and has a generally arcuate shape that opens radially outwardly. The method further includes forming a guide pin head ring with a generally annular plan configuration, a generally cylindrically shaped exterior sidewall having a predetermined outside diameter that is greater than the predetermined outside diameter of the guide pin body, a generally cylindrically shaped interior sidewall with a predetermined inside diameter that is generally commensurate with the predetermined outside diameter of the guide pin body, a generally annularly shaped outwardly facing end edge, and a generally annularly shaped inwardly facing end edge. The method further includes forming a second retainer groove in the guide pin head ring which extends circumferentially about a medial portion of the interior sidewall and has a generally arcuate shape that opens radially inwardly, and is generally axially aligned with the first retainer groove in the guide pin body when the guide pin assembly is in an assembled condition. The method further includes forming a counterbore into the outwardly facing end edge of the guide pin head ring that is recessed into the interior sidewall of the guide pin head ring, extends generally axially from the outwardly facing end edge to the second retainer groove, and defines a counterbore wall. The method further includes providing a retainer ring having a radially inward portion shaped for close reception in the first retainer groove in the guide pin body, and a radially outward portion shaped for close reception in the second retainer groove in a guide pin head ring. The method further includes forming a guide pin head cap with a generally circular plan configuration, an outwardly oriented exterior face, an inwardly oriented interior face, and a generally annularly shaped support collar protruding axially inwardly from the interior face of the guide pin end cap, having a free end edge, a radially interior sidewall defining a socket shaped to closely receive therein the second end portion of the guide pin body, and a radially exterior sidewall shaped to be closely received against the counterbore wall. The method further includes positioning the radially inward portion of the retainer ring in the first retainer groove in the guide pin body, and sliding the guide pin head ring onto and over the guide pin body from the first end portion thereof until the guide pin head ring contacts at least a portion of the retainer ring mounted in the first retainer groove on the guide pin body. The method further includes positioning the guide pin head cap over the outwardly facing end edge of the guide pin head ring with at least a portion of the second end portion of the guide pin body received in the socket in the guide pin head cap, at least a portion of the support collar of the guide pin head cap received in the counterbore in the guide pin head ring. The method further includes converging the guide pin head cap and the guide pin head ring until at least a portion of the free end edge of the support ring on the guide pin head cap contacts at least a portion of the retainer ring mounted in the first retainer groove on the guide pin body. The method further includes pressing the guide pin head cap and the guide pin head ring together, causing engagement of the free end edge of the support ring against the retainer ring mounted in the first retainer groove on the guide pin body, and thereby shifting the radially outward portion of the retainer ring into the second retainer ring groove in the guide pin head ring to fixedly axially mount the guide pin head ring on the second end portion of the guide pin body and define an enlarged head portion of the guide pin assembly that serves to positively limit travel between the first and second die members. The method further includes further pressing the guide pin head cap and the guide pin head ring together until the second end portion of the guide pin body is fully received in the socket in the guide pin head cap, the support collar of the guide pin head cap is fully received in the counterbore in the guide pin head ring, and the inwardly oriented interior face of the guide pin head cap abuts with the outwardly facing end edge of the guide pin head ring to positively capture the retainer ring in the first retainer groove in the guide pin body and the second retainer groove in the guide pin head ring, and rigidly support the guide pin head ring on the second end portion of the guide pin body. The method further includes mounting the first end portion of the guide pin on the first die member, and positioning the second end portion of the guide pin body in an associated aperture in the second die member, such that the enlarged head portion of the guide pin assembly positively and accurately limits travel between the first and second die members during repeated, mutual convergence and divergence of the first and second die members.
Yet another aspect of the present invention is a guide pin assembly having an uncomplicated construction which is economical to manufacture, and very strong and durable during use. Designed interferences between the various parts of the guide pin assembly provide a secure locking function when the parts are assembled. The guide pin head ring elastically deforms both circumferentially and radially outwardly when the guide pin head ring is pressed on the guide pin body to snap the retainer groove in the guide pin head ring over and onto the radially outward portion of the retainer ring, and thereafter apply radially inwardly oriented resilient constricting forces against the retainer ring that securely retains the retainer ring in place without adversely affecting the function of the guide pin assembly. A slight taper may be placed on the outer edge of the guide pin head ring prior to assembly, which flattens straight after the parts have been assembled. The guide pin head cap has a support collar that fills the void between the retainer ring and the adjacent parts to securely support the guide pin head ring when it is subjected to high forces. The guide pin head ring requires no anti-rotation feature, since it can rotate without affecting its function. Assembly of the guide pin assembly is preferably accomplished in one single pressing action, wherein the guide pin head cap drives the retainer ring into the guide pin head ring seat, and is then inelastically deformed to ensure the parts are fully seated. The guide pin head cap is dimensioned to create a seamless appearance on the enlarged head portion of the guide pin assembly, wherein the tangent of the radius on the cap matches the straight on the ring component. Preferably, the marginal edge of the guide pin head cap is quite thin, and is designed to deform rather than allow the parts to be separated. The guide pin head cap can be easily etched or otherwise marked with appropriate indicia before assembly, and preferably has a common size regardless of the length of the guide pin to which it will be assembled. A dampener groove in the guide pin allows a dampening washer retained therein to compress and bulge bi-directionally under normal working conditions, keeping the washer from fanning only outwardly under high loads, and further helps keep the dampening washer in place under all load conditions. The guide pin assembly is efficient in use, economical to manufacture, capable of long operating life, and particularly well adapted for the proposed use.
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 specification, 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 reference numeral 1 (
As will be appreciated by those having skill in the art of metal forming dies, metal forming dies typically incorporate multiple pairs of plates which converge and diverge relative to one another, and serve to either form the metal stock strip, and/or advance the stock strip through the various stations of the metal forming dies. Various tools and/or components are normally mounted on these die plates to achieve the desired forming of the metal stock and/or advancement through the die. These pairs of metal plates are typically interconnected by guide pins, which serve not only to accurately align each plate in the pair for precise reciprocation, but also act as a retainer to positively limit to a predetermined amount the distance each pair of plates may be separated from one another, so as to insure proper synchronization between the various stations and/or operations being performed in the metal forming die. Examples of such components are stock lifters, guided keepers, pressure plates, die shoes, die set pins and the like. Consequently, it should be understood that 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 die shoe, a lower die member, all other die components, whether stationary or reciprocating, including a reciprocating pressure pad, or the like. In the example illustrated in
With reference to
With reference to
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Furthermore, in the illustrated example, the guide pin head ring 15 is constructed of a rigid material having sufficient radial and circumferential resiliency that the guide pin head ring 15 elastically deforms both circumferentially and radially outwardly when the guide pin head ring 15 is pressed onto the guide pin body 5 to snap the second retainer groove 20 over and onto the radially outwardly portion 32 of the retainer ring 30. The guide pin head ring 15, in this elastically deformed installed condition, thereafter applies radially inwardly oriented resilient constricting forces against the retainer ring 30 and guide pin body 5, which serve to securely retain the retainer ring 30 in the first and second retainer grooves 11, 20 of the guide pin body 5 and the guide pin head ring 15 when the guide pin assembly 1 is in the fully assembled condition. As best shown in
The counterbore 21 in the illustrated guide pin head ring 15 defines an annular slot with a predetermined width, as measured radially between the interior sidewall 17 of the guide pin head ring 15 and the counterbore wall 22, which is particularly adapted for the secure connection of the guide pin head cap 40 in counterbore 21, as discussed below.
The illustrated guide pin head cap 40 has a rigid, one-piece construction, and can be machined from a solid bar or rod of metal or the like, such as steel. The support collar portion 43 of guide pin head cap 40 has a predetermined width measured radially between the interior sidewall 44 and the exterior sidewall 46 of the support collar 43, which width is greater than the predetermined width of the counterbore 21 as noted above, such that the guide pin head cap 40 is pressed axially onto the guide pin head ring 15 with an interference fit between the support collar portion 43 of the guide pin head cap 40 and the counterbore wall 22 of the guide pin head ring 15. Furthermore, the support collar portion 43 of the illustrated guide pin head cap 40 includes an inwardly facing free end edge 70, which abuts at least a portion of the retainer ring 30 when the guide pin assembly 1 is in the assembled condition, and assists in positively capturing the retainer ring 30 in the first and second retainer grooves, 11, 20 in the guide pin body 1 and the guide pin head ring 15. In the illustrated example, when the guide pin assembly 1 is being pressed into the assembled condition, as shown in
As will be appreciated by those skilled in the art, because the primary mechanical connection between guide pin body 5 and guide pin head ring 15 is provided by retainer ring 30, a permanent connection between these parts can be achieved without the need for a guide pin head cap 40, although use of the latter is preferred for most commercial applications.
Furthermore, guide pin assembly 1 does not require any anti-rotation mechanism for the enlarged head 33, as a result of the unique locking system achieved by retainer ring 30.
In one working embodiment of the present invention, the guide pin body 5, guide pin head ring 15, retainer ring 30 and guide pin head cap 40 are assembled in the fashion shown in
Guide pin assembly 1 has an uncomplicated construction which is economical to manufacture, very strong and durable during use. Designed interferences between the various parts of the guide pin assembly 1 provide a secure locking function when the parts are fully assembled. The guide pin head ring 15 elastically deforms both circumferentially and radially outwardly when the guide pin head ring 15 is pressed onto the guide pin body 5 to snap the retainer groove 20 in the guide pin head ring 15 over and onto the radially outward portion of the retainer ring 30, and thereafter applies radially inwardly oriented resilient constricting forces against the retainer ring 30 and guide pin body 5 that securely retain the retainer ring 30 in place, without adversely affecting the function of the guide pin assembly 1. A slight taper is placed on the outer edge of the guide pin head ring 15, which stretches into a circular shape or cylinder after the parts have been fully assembled.
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.
The present application is a continuation of commonly assigned U.S. patent application Ser. No. 15/688,961 filed Aug. 29, 2017, entitled GUIDE PIN ASSEMBLY FOR METAL FORMING DIES AND METHOD, which claims priority to U.S. Pat. No. 9,776,233, issued Oct. 3, 2017, entitled GUIDE PIN ASSEMBLY FOR METAL FORMING DIES AND METHOD, which claims priority to U.S. Pat. No. 8,939,005, issued Jan. 27, 2015, entitled GUIDE PIN ASSEMBLY FOR METAL FORMING DIES AND METHOD, which claims priority to commonly assigned U.S. Provisional Patent Application No. 61/611,135, filed Mar. 15, 2012, entitled GUIDE PIN ASSEMBLY FOR METAL FORMING DIES AND METHOD, all of which are incorporated herein by reference.
Number | Date | Country | |
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61611135 | Mar 2012 | US |
Number | Date | Country | |
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Parent | 15688961 | Aug 2017 | US |
Child | 16861532 | US | |
Parent | 14571523 | Dec 2014 | US |
Child | 15688961 | US | |
Parent | 13733160 | Jan 2013 | US |
Child | 14571523 | US |