Anti-Vibration Die Holder Technology for Fabricating Press
The invention involves an anti-vibration die holder for a press, such as a metal-fabricating press. The anti-vibration die holder preferably includes at least one resilient surface adapted to contact a die when the die is mounted operatively on the die holder.
The present invention is in the field of die holders for machine tools. More particularly, this invention relates to die holders for fabricating presses.
BACKGROUND OF THE INVENTIONMetal-fabricating presses, such as turret presses, single-station presses, etc., are used to fabricate sheet metal and other sheet-like workpieces. Commonly, each press includes an upper table and a lower table, and at least one die holder adapted for holding a die securely between the upper and lower tables. In many cases, the die holder is adapted to tightly hold the die with a plurality of set screws. In order to change out a die, the set screws must be loosened before the old die can be removed. Then, the new die can be loaded into the die holder (e.g., after moving the new die into the space between the upper and lower tables). The upper and lower tables of many presses are relatively close together. Thus, replacing dies can be a difficult and time consuming process. In addition, after a pressing operation, the die can be hard to remove from the die holder due to stiction. Stiction occurs when the die becomes stubbornly stuck in the die holder (e.g., due to a close fit between the die and the die holder, and any lubrication present). Stiction causes additional difficulty because the die must be forced from the die holder.
SUMMARY OF THE INVENTIONIn certain embodiments, the invention provides a die holder for a fabricating press. The die holder has an interior recess that is bounded by at least one interior wall and that is configured to receive a die. In the present embodiments, the die holder has an anti-vibration system comprising a resilient surface adapted to engage the die when the die is mounted operatively in the die holder's interior recess. Preferably, the construction of the die holder and its anti-vibration system allow no more than 0.032 inch of upward die displacement relative to the die holder after 10,000 test strokes of the fabricating press.
Some embodiments of the invention provide a method of using a fabricating press equipped with at least one active die holder and at least one inactive die holder. The inactive die holder has an interior recess bounded by at least one interior wall. In the present embodiments, a die is mounted operatively in this interior recess, and this inactive die holder has an anti-vibration system comprising a resilient surface engaged with the die. The present method comprises operating the fabricating press to perform a plurality of strokes adjacent to the active die holder. The construction of the inactive die holder and its anti-vibration system are such that during the plurality of strokes the die experiences no more than 0.032 inch of upward displacement relative to the inactive die holder.
Certain embodiments of the invention provide a die holder for a fabricating press. The die holder has an interior recess that is bounded by at least one interior wall and that is configured to receive a die. In the present embodiments, the die holder has an anti-vibration system comprising a plurality of resilient surfaces adapted to contact the die when the die is mounted operatively in the interior recess. In the present embodiments, the resilient surfaces are spaced-apart about the interior wall(s).
In some embodiments, the invention provides a combination of a die and a die holder for a fabricating press. The die holder has an interior recess bounded by at least one interior wall. In the present embodiments, the die is mounted operatively in the die holder's interior recess. In the present embodiments, the die holder has an anti-vibration system comprising a resilient surface defined by a resilient face in which at least one groove or other recess is formed. Preferably, the grooved or otherwise recessed resilient face is engaged with an exterior sidewall of the die.
The following detailed description is to be read with reference to the drawings, in which like elements in different drawings have like reference numerals. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Skilled artisans will recognize that the given examples have many useful alternatives, which fall within the scope of the invention.
Some embodiments of the invention provide a die holder for a fabricating press, such as a metal-fabricating press. In some cases, the press has an upper table and a lower table. A gap between the upper and lower tables is adapted to receive sheet metal or another sheet-like workpiece. In some cases, the upper table may be omitted. The lower table preferably is adapted to have mounted thereon at least one die holder (a wall portion 140 of the die holder may be mounted fixedly on the table, and a clamp portion 130 of the die holder may, in some cases, be adapted for being removably attached to the wall portion). The lower table commonly has a horizontal surface on which the die holder can be mounted and/or defining a mount opening in which the die holder can be mounted. The mount opening in such a press can optionally have a generally circular configuration. In other cases, the mount opening is adapted to receive a polygonal (e.g., generally square) die holder.
One type of fabricating press is shown in
In some embodiments, the fabricating press 10 includes (e.g., is) a turret press 20. In such embodiments, the turret press 20 can include an upper table (e.g., an upper turret) 30 and a lower table (e.g., a lower turret) 40. The upper table 30 and lower table 40 can be separated by a turret gap 50 adapted to receive sheet-like workpieces. The turret press 20 can include a plurality of stations (reference is made to
For embodiments involving a turret press (or other presses with upper and lower tables separated by a gap), to mount a die 90 within the die holder 70, the die can be moved into the gap and mounted in the die holder.
In some embodiments, the die can be moved into the die holder through an open side of the die holder. The open side (which preferably can be closed once the die is mounted on the die holder) may optionally be bounded underneath by an opening base OB of the die holder. The opening base OB, when provided, desirably has a smaller height than the wall portion 140 of the die holder. Preferably, the opening base OB forms part of the die holder's shelf 110 and defines a portion of the support surface 120 that is adapted to support the bottom of a die. When the clamp portion 130 of the die holder is in a closed configuration, the clamp portion preferably is carried against (e.g., positioned on top of) at least part of the opening base OB.
One exemplary embodiment of a die 90 mounted in a die holder 70 is shown in
In some cases, the die holder is used on a single-station fabricating press. In embodiments of this nature, the press typically does not involve turrets, although the press may still have upper and lower tables (or at least a lower table), as is well known in the present art.
The die holder 70 can include any apparatus useful for holding a die 90. Preferably, the die holder 70 has an interior recess 100. The interior recess 100 may have a generally circular configuration (and/or it may be adapted to receive a die having a generally circular configuration). This, however, is not the case in all embodiments. For example, other embodiments involve a polygonal die 90 and a polygonal interior recess 100. Polygonal dies of the Salvagnini style are known, and the present die holder can be configured to accommodate such dies.
The die holder preferably has a shelf 110 adapted to support a bottom (e.g., a planar base) of a die 90. Reference is made to
In some embodiments, the die holder 70 includes a clamp portion 130 and a wall portion 140. The clamp portion 130 can optionally comprise (e.g., can be) a concave clamp portion (i.e., it can optionally have a concave interior surface). The clamp portion, for example, can have a generally C-shaped configuration as shown in many of the drawings. Additionally or alternatively, the wall portion 140 can optionally comprise (e.g., can be) a concave wall portion.
In some embodiments, the clamp portion 130 and wall portion 140 cooperate to allow the die holder 70 to have a closed configuration, embodiments of which are shown in
The terms “concave clamp portion” and “concave wall portion” do not require the whole of either component to be concave. Preferably, though, a concave clamp portion 130 has a concave interior surface 180, and a concave wall portion 140 has a concave interior surface 190. Those interior surfaces desirably are adapted to surround, abut, and/or engage a die 90 when the die is mounted in the die holder 70 and the die holder is in the closed configuration.
In some embodiments, a concave interior surface 180 of the clamp portion 130 bounds at least 30 degrees, at least 35 degrees, or at least 40 degrees of the interior recess 100 when the clamp and wall portions are in the closed configuration.
In certain embodiments, the die holder 70 also has a clamped configuration, embodiments of which are shown in
In certain embodiments, the die holder 70 includes at least one spring component. Preferably, the spring component is adapted to generate at least part of the clamping force the die holder places on the die. In some cases, the spring component comprises at least one compression spring CSP, optionally provided on the clamp portion 130. Reference is made to
In
In certain embodiments, the die holder includes a spring component having a body comprising (e.g., formed of) spring steel. For example, a spring steel body (optionally having an arcuate shape) can form at least part of the die holder's clamp portion 130. During a clamping operation, the die holder 70 can apply a clamping force on a die 90 (when the die is in the die holder's interior recess 100) and the optional spring steel body may generate at least part of the clamping force. In such embodiments, when the clamp and wall portions are in the closed configuration, a clamping operation preferably can be performed so as to decrease a dimension, such as a diameter, of the interior recess (more generally, this can optionally be the case for various embodiments described in this disclosure).
In many embodiments, the die holder includes an actuator 210. In some of these embodiments, the actuator is adapted to be moved (e.g., manually, or in some cases robotically or otherwise using hydraulics, pneumatics, electronics, magnetics, or the like) in such a way as to move the die holder between clamped and unclamped configurations. In some cases, the actuator is adapted to be moved in one manner (e.g., in one direction) so as to adjust the die holder from an unclamped position to a clamped position, and the actuator can be moved in a different manner (e.g., in a different direction) so as to adjust the die holder from a clamped position to an unclamped position. This, however, is not the case for all embodiments.
In one group of embodiments, the die holder is provided with an actuator 210 comprising a body that moves relative to the clamp portion 130 and/or wall portion 140 during clamping and/or unclamping operations. This moveable body can optionally be a pivotable body that moves pivotally (e.g., about at least one hinge) during the clamping and/or unclamping operations. The pivotable body, for example, can be a handle or a latch.
In certain embodiments, the actuator 210 is a tool-free actuator that allows the unclamping operation, the clamping operation, or both to be tool-free operations (or at least operations that do not involve rotating a set screw or any other threaded fastener). The clamping and/or unclamping operations, for example, may be performed without a wrench or screw driver. Components of the die holder itself, even if removable (e.g., a removable handle actuator), are not considered tools for purposes of the present disclosure.
As described below, some embodiments provide a die holder (which can optionally be a tool-free die holder) that can be clamped and unclamped, and/or adjusted between open and closed configurations, without requiring any assembly or disassembly of the die holder. These embodiments, for example, may involve the die holder having a clamp portion that is pivotally (e.g., hingedly) connected to the die holder's wall portion.
In certain embodiments, the actuator 210 is a single-motion actuator that allows the die holder 70 to be unclamped in response to a single motion of the actuator. (In some of these embodiments, the unclamping operation is also a tool-free operation.) Additionally or alternatively, the actuator 210 can be one that allows the die holder to be clamped in response to a single motion of the actuator 210. In some embodiments of this nature, the die holder must be partially assembled (e.g., the clamp portion may need to be joined to the wall portion, and/or a removable handle may need to be joined to the die holder) before the single-motion clamping can be performed. However, the actual clamping in such embodiments preferably occurs in response to a single motion of a single-motion actuator (the same may be true of the actual unclamping). Exemplary single motions can be pivoting, pressing, sliding, squeezing, or rotating the actuator 210.
In some embodiments, the die holder 70 is provided with an actuator 210 comprising a body (e.g., a handle) that is moved in one direction (once or repeatedly) during the clamping operation and in another direction (optionally an opposite direction) during the unclamping operation. In embodiments involving a die holder 70 with a shelf 110 defining a support surface 120 on which the bottom of a die 90 is adapted to rest, the handle or other body can optionally be moveable in a plane that is at least generally parallel (or at least substantially parallel) to the shelf's support surface (such that the handle or other body moves in that plane to cause the clamping and unclamping operations). If such a die holder 70 is on, for example, a horizontal table (optionally a lower table 40, as shown in
In certain embodiments, when the clamp and wall portions 130, 140 are in an open configuration, a die 90 can be mounted in the die holder 70 by moving the die sideways (in some cases, horizontally) through an open side 220 of the die holder. Reference is made to
In some embodiments, the die holder can be adjusted (e.g., moved) from an unclamped, open configuration to a closed, clamped configuration by pushing together the clamp and wall portions. For example, in embodiments like that of
In certain embodiments, the die holder is mounted on a table (optionally a horizontal table) of a fabricating press in such a way that when the clamp and wall portions 130, 140 of the die holder 70 are in the open configuration, an open side of the die holder faces an exterior perimeter 224 of the metal-fabricating press 20. Reference is made to
As shown in
In the embodiment shown, the clamp portion 130 includes a latch 230, and the latch is hingedly joined to the clamp portion and has a free end 240 that can be hooked onto a catch 250 on the wall portion 140. The illustrated latch 230 has a generally arcuate shape, although this is not required. The clamp portion also includes an actuator 210 connected to the latch 230 (optionally connected pivotably) and adapted to pull the free end 240 of the latch 230 tight against the catch 250 on the wall portion 140 as part of the clamping operation. This exemplifies embodiments where the die holder 70 is adapted for being clamped and unclamped without any assembly or disassembly of the die holder. Thus, one group of embodiments provides a die holder adapted for being clamped and unclamped without any assembly or disassembly. Another embodiment of this nature is shown in
In other cases, the closed configuration involves the clamp portion 130 being attached removably to the wall portion 140, as exemplified in
In the embodiment shown in
In some embodiments, one or more pinch plates (e.g., a stack of contiguous pinch plates) 300 can be included in the die holder's wall portion 140, as shown best in
The pinch plates 300 can be placed into a significantly skewed position relative to the clamp posts in any suitable manner. In the embodiment shown in
A binding-force mechanism like that in
Another embodiment is shown in
In the embodiments of
In
In such embodiments, the die holder is placed in its closed configuration by placing the clamp protrusions 370 in (or proximate to) the corresponding clamp protrusion receivers 390, and then placing (e.g., securing) each clamp cam 350 against its corresponding clamp shoulder 380. In more detail, the clamping operation here includes applying a force (optionally in a generally downward direction) to the actuator 210 so that it tends to pivot relative to the clamp bar 360 in such a manner that each clamp cam 350 articulates against its corresponding clamp shoulder 380 and forces each clamp protrusion 370 further into its corresponding clamp protrusion receiver 390. In some embodiments, the clamp cam 350 is curved so that, during clamping, it can be articulated to such an extent that an apex 400 of the curve has been articulated against, and forced downwardly past, the contact point with cam shoulder 380. At this point, the die holder will not release the die until a substantial external force is applied to the actuator 210 in the opposite direction (e.g., in a generally upward direction) to articulate the apex 400 of the clamp cam 350 upwardly past the contact point with the cam shoulder 380.
In connection with the die 90, some embodiments involve an opening 390 that extends entirely through the die. This, however, is not the case in all embodiments.
In embodiments where grooves, channels, or other recesses RE are provided in the die holder's shelf 110, the recesses optionally have a depth of at least 0.0015 inch (such as at least about 0.04 mm), or at least 0.0019 inch (such as at least about 0.05 mm). In some cases, the recesses RE reduce the amount of surface area (of the shelf) that contacts a die operably mounted on the die holder by at least 20%, at least 35%, or at least 40% (compared to an entirely flat shelf). In the embodiment of
In embodiments where the interior surface 160 of the die holder is provided with one or more relief areas RL, a relief area RL may be located circumferentially between two contact areas COA of the interior surface 160. The interior surface 160 may have one or a plurality of these relief areas RL. Preferably, when a die is clamped by the die holder, contact area(s) COA of the interior surface 160 contact the die, but relief area(s) RL do not. When provided, the relief area(s) may extend from the die holder's shelf all the way up to the top of the die holder's shoulder 150. This, however, is by no means required. In some embodiments, relief areas RL occupy at least 10%, at least 15%, or at least 20% of the die holder's interior side surface 160.
In embodiments where interior corner relief RS is provided, the relief contour can optionally extend along the entire perimetrical extent (e.g., the entire circumferential extent) of the wall portion 140. This, however, is by no means required. For example, other embodiments involve one or more sections of corner relief RS spanning a total of at least 10 degrees, at least 30 degrees, at least 45 degrees, at least 90 degrees, or at least 120 degrees about the die holder. The present invention covers any die holder (of any design described herein, or of any other design) with an interior corner relief RS.
The die holder 70 of
The actuator 210 on the die holder 70 of
In some embodiments, the die holder is moved between open and closed configurations, and/or between clamped and unclamped configurations, automatically (i.e., without manually manipulating the die holder, or without any direct human contact). For example, an automatic actuator actuated by electrical, hydraulic, and/or pneumatic power can be utilized for automatically configuring the die holder. Controls for such an automatic actuator can be included with the fabricating press or a control panel. In some embodiments, a programmable robot (e.g., a robotic arm) can be utilized to automatically actuate the actuator. For example, the various die holder embodiments described above can be configured on a press such that they can be clamped and/or unclamped pneumatically, hydraulically, etc.
Some embodiments of the fabricating press include a table (optionally a turret table) with a plurality of die holders. In those cases (or any other cases), each die holder can optionally be an independently-operable die holder such that performing a clamping operation clamps a single die holder alone and does not simultaneously clamp any other tool holder (e.g., any other die holder), and/or such that performing an unclamping operation unclamps the die holder alone and does not simultaneously unclamp any other tool holder.
Further, any of the fabricating presses or die holders described herein can include means to indicate that the die is received within, and securely clamped in, the die holder. For example, two electrical contacts can be included within the interior recess and a voltage potential can be applied between the two contacts. The contacts can be configured to allow the circuit to be completed only upon successful clamping of the die within the die holder. The completed circuit could be used to signal an indication light (or other means) on the die holder, on a fabricating press, or on a control panel to indicate the die is either clamped or unclamped. If desired, the press, a controller thereof, etc. can be set-up such that it will not initiate pressing operations unless the die holder registers that a (or each) die therein is securely clamped. Further, the system can be adapted to indicate whether the correct die is received in the die holder. If the correct die is not in the die holder, the controller can be set-up such that it will not initiate pressing. Any signals transmitted among the die holder, a press (e.g., a controller thereof), and a die can be sent by wire or by wireless RF means.
In some embodiments, the invention provides a die holder 70 having a die-release mechanism 520. Preferably, the die-release mechanism 520 is useful for overcoming the above-referenced stiction problem. Several exemplary embodiments, which will be discussed in detail below, are shown in
The die-release mechanism is useful for facilitating removal of the die 90 from the die holder 70 by applying a separation force to the die (e.g., so as to overcome stiction force created by lubricant between the die and die holder). In some embodiments, actuating the die-release mechanism 520 involves a contact portion 530 of that mechanism moving at least generally toward a central axis CA of the interior recess (and/or moving at least generally radially inward). Additionally or alternatively, actuating the die-release mechanism 520 may involve a body 524 with a contact portion 530 moving at least generally parallel to (or at least substantially parallel to) a plane in which the shelf's support surface 120 lies. This may involve the body 524 moving horizontally (e.g., if the die holder is mounted on a table of a press). In certain embodiments, actuation of the die-release mechanism 520 involves a contact portion 530 of that mechanism moving at least generally toward (or directly toward) an open side 80 of the die holder. In some cases, actuation of the die-release mechanism 520 involves a contact portion 530 of that mechanism emerging from an opening OP in the die holder's interior surface 160 (the opening OP can optionally be in a concave interior surface of the die holder).
In the embodiment shown in
In some embodiments, the body 524 is adapted to move radially (e.g., at least generally radially, or at least substantially radially) and/or at least generally toward a central axis CA of the interior recess so as to apply a separation force on the die 90, and the body 524 is resiliently biased toward (generally toward, substantially toward, or directly toward) the central axis CA of the interior recess. In such an embodiment, when a die 90 is moved into the die holder 70 and the die holder is moved into its closed configuration, the die 90 will exert sufficient force on the body 524 to retract the body 524 (overcoming the biasing force) into the die holder's wall portion. When the die holder 70 is placed in the open configuration, the body 524 will have sufficient biasing force (e.g., enough spring force) to overcome stiction and move the die 90 (e.g., so as to separate the die from at least one die holder surface to which the die was originally stuck due to the stiction).
In the embodiment of
Thus, in some embodiments, at least a portion of the actuator (e.g., an actuating ring AR thereof) moves along a curved path during actuation of the die-release mechanism.
With continued reference to
One or more keys 544 (e.g., useful for aligning the die within the die holder) can optionally be provided in any embodiment described in the present disclosure. The key can optionally be rigidly fixed to the wall portion, and can be a pin or any other key structure.
An actuating ring AR like that shown in
Another embodiment that allows for selective actuation of the die-release mechanism 520 is shown in
In the embodiment of
In some embodiments, an operator wishing to remove or exchange a die 90 from a fabricating press 10 may do so by first adjusting the die holder 70 from a clamped to an unclamped configuration and from a closed to an open configuration. The die 90 can then be removed from the die holder 70. Another die 90 can be then be placed within the die holder 70, and the die holder can be adjusted to a closed and clamped configuration.
In some embodiments, an operator may use a die-release mechanism 520 to overcome stiction in the process of removing a die 90 from the die holder 70. For example, a constantly biased member (e.g., a spring-loaded body) can be provided (and used) to release the die 90 when the die holder 70 is adjusted from the clamped configuration to the unclamped configuration and/or from the closed configuration to the open configuration. Alternatively, a die-release mechanism 520 may be selectively actuated, e.g., in response to an operator moving the die holder 70 from the closed configuration to the open configuration. In certain embodiments, the operator can selectively actuate the die-release mechanism 520 by moving a wedge member 550 so as to cause the wedge member to bear forcibly against the die 90 (optionally, so as to separate a bottom surface of the die from a support surface of the die holder, which may involve the wedge member lifting the die away from the die holder's shelf/support surface).
Referring to
Referring to
The present invention also provides embodiments wherein a die holder (e.g., a die holder in accordance with any design shown or described herein, or a die holder of any other design) is provided with an anti-vibration system. It is to be understood, for example, that any of the anti-vibration features, systems, methods, and/or embodiments described below (and/or referenced in
It has been discovered that providing a die holder with an anti-vibration system can eliminate or substantially reduce such problems as die creep and die bounce. Die creep occurs when, due to the vibrations that occur during punching operations, one or more inactive dies (i.e., dies at non-punching positions) gradually move upwardly relative to the inactive die holders in which they are mounted. If the problem is not addressed and the die creep becomes significant, then subsequent punching operations will be inaccurate (or the sheet could crash into a raised die in a non-punching location destroying the workpiece).
Preferably, the die holder is provided with an anti-vibration system, and the construction of the die holder and its anti-vibration system allow no more than 0.032 inch of upward die displacement relative to the die holder after 10,000 test strokes of a fabricating press. This 10,000 stroke test involves mounting the die holder in question at a non-punching location on a fabricating press, then performing 10,000 strokes of the press at a punching location (i.e., adjacent to an active die holder), and then measuring the upward displacement of the die on the die holder in question. The test is performed at the highest possible tonnage rating for the fabricating press with the die holder in a position 160 to 180 degrees from the punching station. By way of example, the test strokes can be performed on Finn-Power punch presses, or on other turret style presses (the die holder 70, of course, can be used on other types of fabricating presses, such as single-station presses). Preferred embodiments limit any upward die displacement to no more than 0.03 inch, preferably no more than 0.02 inch, and perhaps optimally no more than 0.01 inch after 10,000 test strokes. The embodiment of
One group of embodiments provides a die holder with an anti-vibration system comprising at least one resilient surface adapted to contact a die when the die is mounted operatively in an interior recess of the die holder. In preferred embodiments, the die holder has a plurality of resilient surfaces, which can advantageously be spaced-apart about the die holder's interior wall(s). It has been discovered that arrangements of this nature (where the resilient surface or surfaces do not entirely surround the die) are advantageous in that they eliminate or significantly reduce stiction. Stiction occurs when, after a die has been mounted operatively in a die holder, the die becomes stuck in the die holder. Stiction is problematic because the die must be forced from the die holder, taking additional time and cutting into the efficiency of the manufacturing process.
In certain embodiments, the die holder includes a plurality of resilient surfaces 700 that cover between about 180 degrees and about 300 degrees of a perimetrical (e.g., circumferential) extent of the die holder's interior wall(s). Reference is made to
Many types of bodies can be used to provide suitable resilient surfaces 700. Some embodiments employ one or more resilient plugs PL (optionally cylindrical or generally cylindrical bodies), which are adapted to contact the die when the die is operatively mounted in the die holder. Such a plug can have its axis generally parallel, perpendicular, or oblique to the die holder's interior wall.
Thus, the bands, plugs, or other bodies defining the resilient surfaces can take many different forms. For example, they can be provided as buttons, spheres, cubes, or the like. Further, the bodies defining the resilient surfaces need not be entirely resilient. For example, a base portion of each body could be rigid, while a die-contacting portion is resilient. Many other useful alternatives will be apparent to skilled artisans given the present teaching as a guide.
Preferably, each resilient surface 700 is defined by a resilient body that protrudes into the die holder's interior recess 100 a sufficient distance to engage the die when the die is operatively mounted in the die holder. Reference is made to
If desired, an adhesive or other fixation means can be employed between the walls of the resilient bodies and recesses in which they are received. The bands, for example, can glued to the holder, or the bands can be shaped to fit a dove tail type slot. The bands can alternatively be adhered by double sided tape. These, however, are merely non-limiting examples.
The resilient surfaces preferably are constructed to provide a slide-resistant engagement between the die holder and the die. Thus, during operation, the die preferably is maintained in a constant (or at least substantially unchanging) position relative to the die holder.
The resilient surfaces can be formed of a resilient non-lubricating material (i.e., a resilient material that is not self-lubricating). Preferred materials include Neoprene (i.e., polychloroprene) and other synthetic rubber compounds. Natural rubber and other resilient materials may also be used. As other examples, polyurethane and other resilient plastics may be used.
In certain embodiments, the resilient surfaces 700 are defined by material having a Shore A durometer of between about 20 and about 95. In one practical example, Neoprene having a Shore A durometer of about 50 is used.
Preferably, when a die is mounted operatively in the die holder's interior recess, the die contacts both the die holder's resilient surfaces 700 and the die holder's interior wall(s). This can be accomplished, for example, by providing the die holder with at least one resilient body having a height that is less than a height of the die holder's interior wall(s). Reference is made to
In some embodiments, a body defining at least one resilient surface 700 has a grooved or otherwise recessed front section adapted to engage the die when the die is mounted operatively in the interior recess 100. Reference is made to
As just one example, grooves can be formed in a band of Neoprene (or another resilient material) by grinding the grooves into the band. The grinding can be done using automatic or manual surface grinding equipment. For example, the Neoprene can be placed on a vacuum plate or double side taped to a steel surface so it can be magnetically secured to the equipment. Alternatively, the neoprene can be extruded with the desired grooves and simply cut to the proper lengths. The preferred depth for the grooves will depend on such variables as the size of the die holder, the size of the die, the type of resilient material used, the size and shape of the resilient bodies, etc. In some practical embodiments, the grooves have a depth of between about 0.005 inch and about 0.030 inch. In one practical embodiment, the grooves have a depth of about 0.015 inch. These dimensions, however, are not limiting to the invention.
By providing suitable grooves or other recesses in the resilient body or bodies that engage the die, one can provide enough compression to get the die to seat firmly against both the die holder's interior wall and the resilient body or bodies. It has been discovered that this is a good way to overcome limitations in the manufacturing tolerances associated with certain resilient materials. This is believed to be particularly advantageous when using material of the noted durometer range. This combination of softness range and grooves or other recesses is believed to give excellent anti-vibration properties.
In one practical embodiment, the die holder has the general construction illustrated in
As is best shown in
As is best shown in
Certain embodiments provide a die holder having a clamp portion 130 and a wall portion 140 wherein at least one resilient surface 700 is (optionally a plurality of spaced-apart resilient surfaces 700 are) provided on each of the clamp portion 130 and the wall portion 140.
Certain embodiments provide a die holder having an exterior wall (e.g., a wall adapted to be engaged by a die shoe on which the die holder can be mounted) on which there is at least one exterior resilient body.
As noted above, an anti-vibration system can be provided advantageously on many different types of die holders. The die holders described above and exemplified in
The invention also provides methods of using an anti-vibration die holder. In certain embodiments, these methods involve mounting a die operatively in the anti-vibration die holder. In some cases, this involves positioning the die in the interior recess 100 of the die holder 70, and then performing a clamping operation on the die holder so as to forcibly clamp the die in the die holder. Depending upon the particular embodiment, this clamping may result in one or more resilient bodies/surfaces 700 being compressed between an exterior sidewall of the die and an interior wall of the die holder.
Other methods involve using an anti-vibration die holder in the process of performing punching operations on a fabricating press.
While a preferred embodiment of the present invention has been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims.
Claims
1. A die holder for a fabricating press, the die holder having an interior recess that is bounded by at least one interior wall and that is configured to receive a die, the die holder having an anti-vibration system comprising a resilient surface adapted to engage the die when the die is mounted operatively in the die holder's interior recess, the construction of the die holder and its anti-vibration system allowing no more than 0.032 inch of upward die displacement relative to the die holder after 10,000 test strokes of the fabricating press.
2. The die holder of claim 1 wherein the construction of the die holder and its anti-vibration system allow no more than 0.01 inch of upward die displacement relative to the die holder after 10,000 test strokes of the fabricating press.
3. The die holder of claim 1 wherein the construction of the die holder and its anti-vibration system allow no more than about 0.005 inch of upward die displacement relative to the die holder after 10,000 test strokes of the fabricating press.
4. The die holder of claim 1 wherein the resilient surface is defined by material having a Shore A durometer of between about 20 and about 95.
5. The die holder of claim 1 wherein the die holder is devoid of set screws adapted to rigidly engage the die during a clamping operation.
6. The die holder of claim 1 wherein the die holder includes at least one spring component, wherein during a clamping operation the die holder applies a clamping force on the die, and wherein the spring component generates at least part of the clamping force.
7. The die holder of claim 1 wherein the die holder includes a clamp portion and a wall portion, wherein the clamp and wall portions are adapted to be positioned in an open configuration or a closed configuration, the clamp and wall portions together surrounding said interior recess when in the closed configuration, wherein the die holder can be adjusted from a clamped configuration to an unclamped configuration by performing an unclamping operation, wherein when the die is received in said interior recess and the die holder is in the clamped configuration the die is clamped securely by the die holder, the die holder being provided with a single-motion actuator that allows the unclamping operation to be performed in response to a single motion of the actuator.
8. The die holder of claim 7 wherein the actuator is a tool-free actuator that allows the unclamping operation to be a tool-free operation.
9. The die holder of claim 7 wherein said interior recess has a generally circular configuration, the clamp portion has a concave interior surface and the wall portion has a concave interior surface, said interior surfaces being adapted to engage the die when the die holder is clamped securely on the die.
10. The die holder of claim 7 wherein the clamp portion is a concave clamp portion and the wall portion is a concave wall portion, and when the clamp and wall portions are positioned in the closed configuration the die holder has a generally annular configuration.
11. The die holder of claim 1 wherein the die holder is mounted on a horizontal table of the fabricating press, the fabricating press being a turret press having a turret with a plurality of stations adapted to receive respective tool holders, the die holder being mounted removably to the turret.
12. A method of using a fabricating press equipped with at least one active die holder and at least one inactive die holder, the inactive die holder having an interior recess bounded by at least one interior wall, wherein a die is mounted operatively in said interior recess, the inactive die holder having an anti-vibration system comprising a resilient surface engaged with said die, the method comprising operating the fabricating press to perform a plurality of strokes adjacent to the active die holder, the construction of the inactive die holder and its anti-vibration system being such that during the plurality of strokes said die experiences no more than 0.032 inch of upward die displacement relative to the inactive die holder.
13. The method of claim 12 wherein during the plurality of strokes said die experiences no more than 0.02 inch of upward die displacement relative to the inactive die holder.
14. The method of claim 12 wherein during the plurality of strokes said die experiences no more than 0.01 inch of upward die displacement relative to the inactive die holder.
15. The method of claim 12 wherein the plurality of strokes is at least 10,000 strokes.
16. The method of claim 12 wherein the construction of the inactive die holder and its anti-vibration system allow no more than 0.032 inch of upward die displacement relative to the inactive die holder after 10,000 punch strokes of the fabricating press adjacent to the active die holder.
17. The method of claim 12 wherein the resilient surface is defined by material that has a Shore A durometer of between about 20 and about 95 and that bears against said die during the plurality of strokes so as to dampen vibrations.
18. The method of claim 12 wherein the die holder is devoid of set screws adapted to rigidly engage the die during a clamping operation, such that during the plurality of strokes said die is not engaged by any set screw.
19. A die holder for a fabricating press, the die holder having an interior recess that is bounded by at least one interior wall and that is configured to receive a die, the die holder having an anti-vibration system comprising a plurality of resilient surfaces adapted to contact the die when the die is mounted operatively in said interior recess, the resilient surfaces being spaced-apart about said interior wall(s).
20. The die holder of claim 19 wherein the resilient surfaces have an anti-stiction arrangement characterized by the resilient surfaces covering between about 180 degrees and about 300 degrees of a perimetrical extent of said interior wall(s).
21. The die holder of claim 19 wherein the resilient surfaces are constructed to provide slide-resistant engagement between the die holder and the die.
22. The die holder of claim 19 wherein the resilient surfaces are defined by resilient non-lubricating material.
23. The die holder of claim 19 wherein the die, when mounted operatively in said interior recess, contacts both the resilient surfaces and said interior wall(s) of the die holder.
24. The die holder of claim 23 wherein the resilient surfaces are defined by resilient bodies each having a height that is less than a height of said interior wall(s).
25. The die holder of claim 23 wherein said interior wall(s) comprise metal, and said resilient surfaces are defined by material having a Shore A durometer of between about 20 and about 95.
26. The die holder of claim 19 wherein, when the interior recess of the die holder is unloaded, the resilient surfaces project from the die holder's interior wall(s) by at least about 0.001 inch, and wherein when the die holder is clamped on the die the resilient surfaces are compressed such that an exterior sidewall of the die simultaneously contacts both the resilient surfaces and the die holder's interior wall(s).
27. The die holder of claim 26 wherein, when the interior recess of the die holder is unloaded, the resilient surfaces project from the die holder's interior wall(s) by between about 0.001 inch and about 0.005 inch.
28. The die holder of claim 19 wherein a body defining at least one of the resilient surfaces has a grooved front section adapted to engage the die when the die is mounted operatively in said interior recess.
29. The die holder of claim 19 wherein a plurality of bodies define the resilient surfaces, and wherein each such body has a grooved front section adapted to engage the die when the die is mounted operatively in said interior recess.
30. The die holder of claim 19 wherein at least one of the resilient surfaces is defined by an elongated band mounted in a recess extending circumferentially about said interior wall(s).
31. The die holder of claim 30 wherein a plurality of grooves are formed in the elongated band, the grooves extending along a length of the band.
32. The die holder of claim 30 wherein the die holder carries a plurality of spaced-apart grooved elongated bands defining the resilient surfaces.
33. The die holder of claim 19 wherein the die holder includes at least one spring component, wherein during a clamping operation the die holder applies a clamping force on the die, and wherein the spring component generates at least part of the clamping force.
34. The die holder of claim 19 wherein the die holder includes a clamp portion and a wall portion, wherein the clamp and wall portions are adapted to be positioned in an open configuration or a closed configuration, the clamp and wall portions together surrounding said interior recess when in the closed configuration, wherein the die holder can be adjusted from a clamped configuration to an unclamped configuration by performing an unclamping operation, wherein when the die is received in said interior recess and the die holder is in the clamped configuration the die is clamped securely by the die holder, the die holder being provided with a single-motion actuator that allows the unclamping operation to be performed in response to a single motion of the actuator, at least one of the resilient surfaces being mounted on the die holder's wall portion, and at least one of the resilient surfaces being mounted on the die holder's clamp portion.
35. The die holder of claim 34 wherein the actuator is a tool-free actuator that allows the unclamping operation to be a tool-free operation.
36. The die holder of claim 34 wherein said interior recess has a generally circular configuration, the clamp portion has a concave interior surface and the wall portion has a concave interior surface, said interior surfaces being adapted to engage the die when the die holder is clamped securely on the die.
37. The die holder of claim 34 wherein the clamp portion is a concave clamp portion and the wall portion is a concave wall portion, and when the clamp and wall portions are positioned in the closed configuration the die holder has a generally annular configuration.
38. The die holder of claim 19 wherein the die holder is mounted on a horizontal table of the fabricating press.
39. The die holder of claim 19 wherein the die holder is mounted removably within an opening defined by a table of the fabricating press.
40. The die holder of claim 19 wherein the fabricating press is a turret press having a turret with a plurality of stations adapted to receive respective tool holders, the die holder being mounted removably to the turret.
41. A combination of a die and a die holder for a fabricating press, the die holder having an interior recess bounded by at least one interior wall, the die being mounted operatively in the die holder's interior recess, the die holder having an anti-vibration system comprising a resilient surface defined by a resilient face in which at least one groove or other recess is formed, wherein the grooved or otherwise recessed resilient face is engaged with an exterior sidewall of the die.
42. The combination of claim 41 wherein a plurality of generally parallel grooves are formed in the resilient face.
43. The combination of claim 41 wherein the die holder is provided with a plurality of resilient surfaces that are spaced-apart about the die holder's interior wall(s) and that are in contact with the die, the resilient surfaces being defined by grooved bands or other grooved elongated bodies, the grooves on each band or elongated body being arranged so as to be generally parallel to one another and to extend along a circumferential extent of an exterior sidewall of the die.
44. The combination of claim 43 wherein the grooved bands or other elongated bodies contact between about 180 degrees and about 300 degrees of a circumferential extent of an exterior sidewall of the die.
45. The combination of claim 41 wherein the resilient surface is defined by material having a Shore A durometer of between about 20 and about 95.
46. The combination of claim 41 wherein, when the interior recess of the die holder is unloaded, the resilient surface projects from the die holder's interior wall by at least about 0.001 inch
47. The combination of claim 41 wherein the die holder's interior wall is formed of metal, and the die is in contact with both the resilient surface and the metal interior wall of the die holder.
Type: Application
Filed: Jun 27, 2008
Publication Date: Dec 31, 2009
Inventors: Brian J. Lee (Elk River, MN), Jon M. Shimota (Stillwater, MN), Richard L. Timp (Vadnais Heights, MN)
Application Number: 12/163,536
International Classification: B21J 13/00 (20060101); B21D 22/00 (20060101); B21C 3/00 (20060101);