Patent Application
20080060407
At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred aspects, it is to be understood that the invention as claimed is not limited to the disclosed aspects. In the description below, the terms “top”, “bottom”, “upper”, “lower”, “front”, “back”, “rear”, “left”, “right”, and their derivatives, should be interpreted from the perspective of one viewing the press shown in
Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described.
Cushion assembly 12 is used in conjunction with press 8 to form the aforementioned door skins. Cushion assembly 12 has manifold 14 with multiple cushions 16 detachably connected. Cushions 16 are gas-filled cylinders that have an outer housing with a piston centered within the housing. Cushions 16 have an inert gas, such as nitrogen, injected into a chamber in the cylinder to effect pressure in the cushions. Pressure adjustments in cushions 16 affect the resiliency and support the cushions provide.
Resting atop cushions 16 is transfer pad 18 with solid block 20, formed separately from transfer pad 18, but disposed in opening 22 in transfer pad 18. Solid block 20 and opening 22 are depicted in this particular figure to be rectangular shaped, but various other shaped and sized sections could also be implemented some of which will be described in greater detail infra. Conventional cushion assemblies have cushion cylinders distributed across the surface of the manifold, as opposed to cushion assembly 12 which an interior that is empty except for block 20. This reduction in the number of cushion cylinders reduces the failure rate just by reducing the number of cushions required. The failure rate of cushions 16 is also reduced by replacing the section of cushion assembly 12 that absorbs the impact of the die set stamping, namely the interior, with solid block 20.
Manifold 14 distributes pressurized gas to cushions 16 that can be detachably connected to the manifold. Ports 24 in the side of manifold 14 can provide access to the interior recesses of manifold 14, and can enable gas bank 26, or another gas dispensing unit, to pressurize and regulate the pressure in cushions 16. Gas bank 26 holds pressurized gas that is fed through line 28 to feed port 23 in manifold 14, and pressure valve 29 and gauge 25 is implemented as a means to regulate and monitor gas pressure. In some aspects, gas bank 26 provides the gas pressure throughout manifold 14 and the individual cushion cylinders 16, as manifold 14 connects cylinders 16 on a circuit. In some aspects, the gas contained in gas bank 26, and distributed through manifold 14 and cushions 16 is nitrogen gas. Other gases used in pressurized systems, such as cushion cylinders 16, that are known in the art can be substituted for nitrogen gas. Consequently, the gas that pressurizes manifold 14 and cushions 16 is not limited to only nitrogen.
In some aspects, cushions 16 are detachably connected to manifold 14, and all cushions 16 are in a pressurized circuit. Therefore, increasing or decreasing the pressure in manifold 14 increases or decreases the pressure in all the cushions connected to manifold 14. In other aspects, it may be beneficial to regulate and adjust pressure in cushions individually (not shown). To accomplish this adjustment, pressure is regulated by pressure valves that are dedicated to single cushions, which can be manually controlled or regulated and adjusted by an automated process controlled by an electronic system. Providing adjustability to individual cushions enables the operator of the press to control the amount of support transfer pad 18 provides at different regions of the manifold to adapt to different die sets or embossments intended. Certain die sets may require additional support only at a portion of the perimeter of the manifold, and regulating pressures in cushions on an individual basis enables the cushion assembly to adapt to those parameters. Cushions 16 can be commonly used gas-charged shock absorption units of varying dimension and pressure ranges. Gas springs or cushions that are capable of varying pressures exerted by the devices are preferred since they enable the press to be adapted to different applications and production requirements.
It should be appreciated that cushions 16 can be detachably connected to manifold 14 using various detachable connection means, and that illustrations showing threaded connections are only one possible alternative. Any of the various detachable connection means known in the art can be implemented. Furthermore, in some aspects, cushions 16 can be connected to manifold 14 using a connection that is not detachable.
In some aspects, solid block 20 is a height sufficient to have the top of block 20 to remain generally flush with the top of transfer pad 18 when cushion assembly 12 is fully assembled. The fit of block 20 is also complementary to opening 22 in that the parameters of block 20 is roughly equivalent to the parameters of opening 22. As die set 32 is pressed downward against cushion assembly 12, solid block 20 provides support for female die 34 and male die 36 to emboss sheet steel blanks that are placed between female die 34 and male die 36. Cushions 16 provide pressurized resistance around the perimeter of cushion assembly 12 that distributes force exerted by press 8 to the perimeter, which enables cushion assembly 12 and die set 32 to compress and grip the perimeter of sheet steel blanks that are pressed. In some aspects, block 20 is positioned to provide support at regions where die set 32 will emboss a blank. Specifically, embossments may only be pressed into the blank at regions where solid support has been provided. As die set 32 is pressed against transfer pad 18 and solid block 20, cushions 16, arranged around the perimeter of manifold 14, force transfer pad 18 to bind the perimeter of sheet steel blanks inserted into die set 32 to prevent slipping of the blank during stamping. This compression or gripping of the blank at the perimeter, which is caused by the perimeter cushions 16 exerting resistance against transfer pad 18, facilitates that the blank is not warped or deformed to any undesirable extent when die set 32 punches out the embossment in the blank. Solid block 20 ensures that die set 32, which has higher definition dies, can effectively punch out the higher definition embossments in the blank. Higher definition refers to a higher number of radii distributed possible across an embossment, the depth and profile ranges of the door skin embossments is broader and/or the embossments are more defined with shadowing that gives a more pronounced appearance. In some aspects, transfer pins (not shown) that are solid steel structures that extend from the base of the perimeter of die set 32 can be used to exert force on transfer pad 18 as press 8 stamps a steel blank. The transfer pins are best positioned on the bottom and at the perimeter of the die set and can ensure that the edge of blank is securely held to prevent warping as the die set stamps the embossment in the blank.
Solid block 20 is shown attached to manifold 14 with threaded attachment means. In some embodiments, solid block 20 can have a threaded base that threads into threaded bolts in manifold 14, or can be detachably connected in another manner known in the art. In some aspects, solid block 20 is fixedly attached to manifold 14. Solid block 20 has a height that is roughly the combined height of cylinders 16 and transfer pad 18, and block 20 has a width and length that is roughly equivalent to the width and length of opening 22.
Solid block 20 has been replaced by multiple solid blocks 120 in the interior of manifold 14. Multiple solid blocks 120 function similarly to the solid block 20 in that solid blocks 120 support male die 36 and female die 34 to enable the stamping of previously unattainable embossment designs. Blocks 120 and openings 122 are depicted as a rectangular, but other possible alternative shapes can be used depending on the die set chosen or the press used, or other reasons. As die set 32 is pressed against transfer pad 118 and solid blocks 120, cushions 116 arranged around the perimeter of manifold 114 force transfer pad 118 to bind the perimeter of sheet steel blanks inserted into die set 32 to prevent slipping of the blank during stamping. This compression or gripping of the blank at the perimeter, which is caused by the perimeter cushions 116 exerting resistance against the transfer pad, facilitates that the blank is not warped or deformed to any undesirable extent when the die set punches out the embossment in the blank. Solid blocks 120 ensure that die set 32, which has higher definition dies, can effectively punch out the higher definition embossments in the blank. In some aspects, transfer pins (not shown) that are solid steel structures that extend from the base of the perimeter of die set 32 can be used to exert force on transfer pad 118 as the press 8 stamps a steel blank. The transfer pins are best positioned on the bottom at the perimeter of the die set and can ensure that the edge of blank is securely held to prevent warping as the die set stamps the embossment in the blank.
A cross-sectional view of cushion assembly 112 taken generally along line 6-6 in
Solid blocks 120 are shown attached to manifold 114 with threaded attachment means. In some embodiments, solid blocks 120 can have a threaded base that can be attached with a threaded attachment means to manifold 114, or can be detachably connected in another manner known in the art. In some aspects, solid blocks 120 are fixedly attached to manifold 114. Solid blocks 120 have a height that is roughly the combined height of cylinders 116 and transfer pad 118, and blocks 120 has a length and width that is roughly equivalent to the length and width of openings 122. Openings 122 are shaped and sized to be complementary with blocks 120. Any vertical displacement of transfer pad 118 will have solid blocks 120 riding within openings 122.
The interior of manifold 114 has multiple solid blocks 120 arranged to support die set 32 as press 8 compresses a blank that has been inserted between female die 34 and male die 36. The perimeter arrangement of cushions 116 supports transfer pad 118, with cushions 116 providing the resistance that enables the transfer pad to compress the perimeter of a sheet steel blank to prevent movement or suck of the blank edge during stamping. Solid blocks 120 provide the support for die set 32 as the press stamps a blank. Perimeter binding of the blank edge, due to cushions 116 around the perimeter, combined with the contrasting non-cushioned center of manifold 114, due to solid blocks 120, produces a door skin with embossments that are more refined with higher definition. The perimeter edge of the door skin produced by press 8 using cushion assembly 112 can reduce or eliminate warping, due to the perimeter cushioning and solid center of manifold 114. As die set 32 is pressed against transfer pad 118 and solid blocks 120, cushions 116 arranged around the perimeter of manifold 114 force the transfer pad to bind the perimeter of sheet steel blanks inserted into die set 32 to prevent slipping of the blank during stamping. This compression or gripping of the blank at the perimeter, which is caused by the perimeter cushions 116 exerting resistance against the transfer pad, facilitates that the blank is not warped or deformed to any undesirable extent when the die set punches out the embossment in the blank. Solid blocks 120 ensure that die set 32, which has higher definition dies, can effectively punch out higher definition embossments in the blank.
Due to the force exerted by cushions 16 against the bottom of transfer pad 18, and the solid block 20 in the interior of cushion assembly 12, die sets that punch higher definition embossments are possible without warping or stressing blanks 38. Solid block 20 in cushion assembly 12 provides the rigid support needed to produce higher definition embossments that have greater detail, increased radii, and profiles with broader depth and width ranges. Cushions 16, lining the perimeter of the cushion assembly, provide the gripping force needed to prevent blank 38 from slipping, warping, or deforming during this intense pressing process. Similar support is provided by solid block 20 and solid blocks 120, and cushions 116 function similarly to cushions 16. The stamping process described is applicable and functions similarly with cushion assemblies 12 and 112.
An increased number of radii produced by die set 32 are possible due to the characteristics of cushion assemblies 12 and 212 and the disclosed method. In some aspects, radii 306, 308, 310 and 312 can be stamped into a sheet steel blank using the process and apparatus described supra. Alternative embossment designs, with more than four radii, can also be stamped into steel blanks with different die sets, due to cushion assemblies 12 and 112. Cushion assemblies 12 and 112, and obvious variants of those cushion assemblies can accommodate higher definition die sets that previous cushion assemblies were not capable of handling. Pressing more complex die sets with more than three radii using traditional cushion assemblies would cause tearing, warping, and/or strain on steel blanks.
Thus, it is seen that the objects of the invention are efficiently obtained, although changes and modifications to the invention should be readily apparent to those having ordinary skill in the art, without departing from the spirit or scope of the invention as claimed. Although the invention is described by reference to a specific preferred embodiment, it is clear that variations can be made without departing from the scope or spirit of the invention as claimed.
