Patent Application
20060277970
The present invention relates generally to industrial presses. More particularly, this invention relates to press brakes and press brake tooling.
Press brakes are commonly used to bend or otherwise deform sheet-like workpieces, such as sheet metal workpieces. A conventional press brake has an upper beam and a lower beam, at least one of which is movable toward and away from the other. Typically, the upper beam is movable vertically while the lower beam is fixed in a stationary position. It is common for a male forming punch and a female forming die to be mounted respectively on the upper and lower beams of a press brake.
Typically, the punch has a downwardly oriented, workpiece-deforming surface (or “tip”). The configuration of this surface is dictated by the shape into which it is desired to deform a workpiece. The die typically has a recess, bounded by one or more workpiece-deforming surfaces, that is aligned with the tip of the punch. The configuration of this recess corresponds to the configuration of the punch's tip. Thus, when the beams are brought together, a workpiece between them is pressed by the punch into the die to give the workpiece a desired deformation (e.g., a desired bend).
In order to accurately deform a workpiece, it is necessary for the tools to be mounted securely on the tool holder. This is accomplished by forcibly clamping the holder about each tool. Multiple steps are sometimes required, for example, to mount a punch on the upper beam of a press brake. The punch may be moved into an initial-mount position by lifting the shank of the punch upwardly between a support plate and clamp of the tool holder. In some cases, when the punch is moved into this position, a safety key of the punch engages a safety slot of the tool holder. In other cases, a safety groove on the punch is engaged by a lip on the clamp of the tool holder. Either way, the tool holder is subsequently clamped forcibly on the shank of the punch. Even at this point, the load-bearing surfaces of the tool holder and punch may not be securely engaged. Rather, additional steps may be required. For example, with many tool holder designs, the upper and lower tables of the press brake must subsequently be moved together until the punch comes into contact with a die on the lower table. By forcing the tip of the punch against the die, the punch can be urged upwardly relative to the tool holder until the load-bearing surface(s) of the tool is/are moved into contact with the corresponding load-bearing surface(s) of the tool holder. When a punch is in this operative position, the load-bearing surfaces of the tool holder and punch are engaged and the tang of the punch is forcibly clamped, e.g., between a support plate and clamp of the tool holder. During pressing operations, the punch is maintained in this position. Thus, several steps may be required to operatively mount a punch on the upper table of a press brake.
It would be desirable to provide a tool that can be operatively clamped by a tool holder in such a way that the load-bearing surfaces of the tool and tool holder are engaged as an adjunct of the clamping action of the tool holder (e.g., without having to press the tip of a loosely-clamped punch against a die on the lower table of the press brake). The present invention provides new press brake tool technologies, in which a seating and/or locating mechanism is incorporated into the tool.
Press brake tool seating has been attempted in a few instances by building tool seating mechanisms into press brake tool holders. These tool holder mechanisms may be less than ideal in terms of their complexity, propensity to fail, etc. Furthermore, building a seating mechanism into the tool holder requires a machinist to possess a specialized tool holder in order to enjoy the benefits of tool seating. Some embodiments of the present invention provide a press brake tool wherein a seating mechanism is incorporated into the tool itself. Thus, a machinist can accomplish tool seating using any of a variety of conventional press brake tool holders.
In certain embodiments, the invention provides a press brake tool configured for being operatively mounted on a tool holder of a press brake having a pressing axis. The tool has a shank adapted for being positioned in a tool-mount channel of the tool holder such that the shank when clamped forcibly between confronting walls of the tool holder receives a force having a clamping component directed at least generally perpendicular to the pressing axis. In the present embodiments, the tool has a seating mechanism adapted for at least partially converting this force into a seating component directed at least generally parallel to the pressing axis. Preferably, the seating mechanism comprises a moveable body mounted on the tool so as to be moveable relative to a stationary portion of the tool's shank.
In certain embodiments, the invention provides, in combination, a press brake tool and a tool holder of a press brake having a pressing axis. In the present embodiments, the tool is operatively mounted on the tool holder. The operatively mounted tool has a shank positioned in a tool-mount channel of the tool holder such that the shank is clamped forcibly between confronting walls of the tool holder, the tool's shank thereby receiving from the tool holder a force having a clamping component directed at least generally perpendicular to the pressing axis. In the present embodiments, the tool has a seating mechanism at least partially converting this force into a seating component directed at least generally parallel to the pressing axis. In the present embodiments, the seating mechanism comprises a moveable body mounted on the tool so as to be moveable relative to a stationary portion of the tool's shank.
In certain embodiments, the invention provides a method of mounting a press brake tool on a tool holder (of a press brake) having a pressing axis. The tool holder has a tool-mount channel bounded by first and second confronting walls. In the present embodiments, the first confronting wall of the tool holder is moveable at least in part toward the second confronting wall of the tool holder. The tool holder has at least one load-delivering surface (in some embodiments, it is adapted for moving the tool, when operatively mounted on the tool holder, along the pressing axis). The tool has a shank and at least one load-receiving surface. In the present embodiments, the tool has a seating mechanism comprising a moveable body mounted on the tool so as to be moveable relative to a stationary portion of the tool's shank. The present method comprises positioning the tool's shank in the tool-mount channel and moving the first confronting wall at least in part toward the second confronting wall thereby forcibly clamping the tool's shank between these confronting walls so as to deliver to the shank a force that is at least partially converted by the tool's seating mechanism into a seating component directed at least generally parallel to the pressing axis. Preferably, the seating component of this force moves the tool relative to the tool holder so as to bring the load-receiving surface of the tool into engagement with the load-delivering surface of the tool holder.
In certain embodiments, the invention provides a press brake tool having a shank that is provided with a retractable safety key. Here, the safety key is moveable between an extended position and a retracted position. Preferably, the safety key is operably coupled with a moveable link member such that the safety key moves from its extended position to its retracted position in response to the link member moving along a vertical axis of the tool.
In one group of embodiments, the invention provides a press brake tool having a shank adapted for being positioned in a tool-mount channel of a tool holder, and a ball member is mounted on the tool so as to be moveable relative to a stationary portion of the tool's shank. Here, the ball member is moveable between an extended position and a retracted position, and at least a portion of the ball member projects outwardly from the tool's shank when the ball member is in its extended position. In some embodiments of this nature, the ball member comprises a metal sphere. Optionally, the tool's shank has a lateral width and the ball member is a sphere having a diameter of at least about ⅕th (perhaps more preferably at least about ¼th) this lateral width. In some of the present embodiments, the tool's shank has two generally opposed sidewalls, a portion of the ball member projects outwardly from a first of these sidewalls when the ball member is in its extended position, and a second of these sidewalls is at least generally planar. Conjointly, the tool can optionally include a load-receiving surface that is at least generally planar, and this load-receiving surface can optionally be at least generally perpendicular to the second of the noted sidewalls of the tool's shank. An optional feature in the present group of embodiments (and in the other embodiments described throughout the present specification) is that the tool's shank has a non-cylindrical configuration. Optionally, the ball member is housed in a bore of the tool, at least part of a spring member is disposed in this bore, and the spring member is adapted for resiliently biasing, either directly or via one or more other bodies, the ball member toward its extended position. Conjointly, an elongated link member can optionally be housed in the bore, the elongated link member can optionally have opposed first and second end regions, the link member can optionally be slidable in the bore between first and second positions, the ball member can optionally assume its extended position when the link member is in its first position, the ball member can optionally be slidable in the bore between its extended and retracted positions, and the spring member optionally bears forcibly against the second end region of the link member to resiliently bias the link member toward its first position. The optional link member in the bore can, for example, be located between the ball member and the spring member. The tool can optionally include an actuator that can be operated so as to cause the link member to slide to its second position, thereby overcoming the resilient bias of the optional spring member and allowing the ball member to move to its retracted position. When provided, the actuator can optionally comprise a moveable cam body that is adapted to bear forcibly against, and cam with, a cam surface of the link member (when the actuator is operated so as to cause the link member to slide to its second position). The optional link member can comprise (e.g., be) an elongated shaft having therein formed a notch that defines the cam surface of the link member. In some cases, the link member comprises an elongated shaft having a concave first end region in which a portion of the ball member is nested (at least when the ball member is in its extended position).
In certain embodiments, the invention provides a press brake tool configured for being operatively mounted on a tool holder of a press brake having a pressing axis (the tool holder in some, but not all, cases is adapted for moving the tool when operatively mounted on the tool holder along the pressing axis). The tool has a shank adapted for being positioned in a tool-mount channel of the tool holder such that the shank when clamped forcibly between confronting walls of the tool holder receives a force having a clamping component directed at least generally perpendicular to the pressing axis. In the present embodiments, the tool has a seating mechanism that is adapted for at least partially converting this force into a seating component directed at least generally parallel to the pressing axis. Preferably, the seating mechanism comprises a moveable body mounted on the tool so as to be moveable relative to a stationary portion of the tool's shank. In the present embodiments, this moveable body comprising a polymer.
In certain embodiments, the invention provides a press brake tool configured for being mounted on a tool holder of a press brake by moving a shank of the tool vertically into a tool-mount channel defined by the tool holder. In the present embodiments, the tool is adapted for being dismounted from the tool holder by moving the tool horizontally out of the channel, and the tool is not adapted for being dismounted from the tool holder by moving the tool vertically out of the channel. In these embodiments, the tool preferably has no externally accessible actuator for retracting the safety key such that once the tool's shank is moved into an operative position in the channel of the tool holder a press brake operator is prevented from retracting the safety key and removing the tool vertically from the tool holder. The press brake has a pressing axis. In the present embodiments, the tool's shank has a retractable safety key and is adapted for being positioned in the channel of the tool holder such that the shank when clamped forcibly between confronting walls of the tool holder receives a force having a clamping component directed at least generally perpendicular to the pressing axis. The tool has a seating mechanism adapted for at least partially converting this force into a seating component directed at least generally parallel to the pressing axis, and the seating mechanism preferably comprises a moveable body mounted on the tool. In the present embodiments, the seating component of the noted force preferably is adapted to move the tool relative to the tool holder so as to bring a load-bearing surface of the tool into engagement with a load-bearing surface of the tool holder. In some embodiments of the present group, the tool is provided in combination with the tool holder, and the tool holder has no externally accessible actuator for causing the tool's safety key to retract such that once the tool's shank is moved into the operative position in the channel of the tool holder the press brake operator is prevented from retracting the safety key and removing the tool vertically from the tool holder. Further, in some of the present embodiments, the tool has a leading body portion that terminates at a tip (the leading body portion being that portion of the tool that is not concealed by the tool holder when the tool's shank is in its operative position in the channel of the tool holder), and the leading body portion of the tool is defined entirely by solid wall having no openings.
The invention in some embodiments provides a brake press tool in combination with a press brake tool holder. Generally, the tool holder TH defines a channel C configured for receiving the shank S of a press brake tool TL. This channel C is referred to herein as the tool-mount channel. In some embodiments, the tool-mount channel C has a generally T-shaped cross section, although this is by no means required. Preferably, at least part of the channel C is bounded by two confronting walls CW, CW′ of the tool holder. In the illustrated embodiments, the confronting walls CW, CW′ are at least generally vertical and/or each define at least one surface that is substantially vertical and planar. These features, however, are not required in all embodiments. For example, the configuration and construction of the wall(s) bounding the tool-mount channel C will vary depending upon the particular style in which the tool holder is embodied.
The tool holder, when provided, will commonly be adapted for use with American style tools. However, the tool holder can take the form of various other tool holder styles known in the art, including those currently in less widespread use. In fact, it will be appreciated that the tool holder TH can be adapted for use with any desired tooling style, including styles not yet developed, that would benefit from the features of this invention. The tool holder, of course, can be a press brake beam, an adaptor mounted to a press brake beam, or any other type of press brake tool holder.
The press brake tool TL can be a male forming punch or a female forming die. Typically, the tool TL has generally opposed first and second ends (or sides). Preferably, the first end (or side) of the tool defines a workpiece-deforming surface TP (e.g., at a tip of the tool) configured for making a desired deformation (e.g., a bend) in a workpiece when this surface TP is forced against the workpiece (e.g., when a tip of the tool is forced against a piece of sheet metal or the like, and/or when a workpiece is forced against the tool's tip). The second end (or side) of the tool has a shank (or “tang”) S configured for being mounted in (e.g., sized and shaped to be received in) the tool-mount channel C.
In some cases, the tool TL has a safety key SK. As shown in
In embodiments involving a tool TL with a safety key SK, the key preferably comprises an engagement portion 580 that is adapted to project into a safety recess SR (and/or into alignment with a safety shelf SCS) defined by the tool holder TH. In the case of a non-retractable safety key, the key will typically comprise a rigid projection from the tool's shank. When provided, the non-retractable safety key preferably is either integral to the tool's shank or rigidly joined to the tool's shank.
In the case of a retractable safety key, the key is mounted on the tool so as to be moveable between an extended position and a retracted position. In more detail, such a key preferably comprises a rigid engagement portion 580 that is moveable relative to (e.g., generally toward and away from) the tool's shank (or at least relative to stationary portions of the shank). Such retractable safety keys are described in U.S. Pat. No. 6,467,327 and U.S. patent application Ser. No. 10/742,439. In some cases, the safety key is part of a key assembly (e.g., mounted inside and/or on the tool) comprising at least one spring member resiliently biasing (directly or via one or more link members and/or other bodies) the safety key SK toward its extended position.
Thus, in some embodiments, the tool holder defines a safety recess SR. When provided, the safety recess SR preferably is sized to receive an engagement portion 580 of a desired safety key SK. In some embodiments involving a tool TL with its shank S received in the channel C of a tool holder TH, the tool holder has a safety recess SR that is at the same elevation as a safety key SK on the tool. Some embodiments of this nature (such as that shown in
Thus, certain embodiments provide a tool holder and tool in combination. In some of these embodiments, the second end of the tool has a shank S received in the tool holder's channel C. As noted above, the channel C is typically bounded at least in part by two confronting walls CW, CW′ of the tool holder. In many combination embodiments, the tool's first end (which typically defines a tip) projects (e.g., generally vertically) away from the tool holder.
Typically, the tool holder TH has at least one load-delivering surface LD configured for engaging a load-receiving surface LR of a press brake tool TL. Preferably, the tool holder TH has one or more generally or substantially horizontal load-delivering surfaces LD each being adapted to engage and deliver force to (when the tool is operatively mounted on the tool holder) one or more corresponding generally or substantially horizontal load-receiving surfaces LR of the tool TL. In some embodiments involving a tool in combination with (and operatively mounted on) a tool holder, the tool holder has a load-delivering surface LD engaged with (e.g., carried directly against) a load-receiving surface LR of the tool TL. Preferably, these engaged surfaces LD and LR are generally or substantially horizontal. In some cases, the tool holder TH has two horizontal load-delivering surfaces LD. For example,
The illustrated load-delivering surfaces LD of the tool holder are configured for engaging, and delivering force to, corresponding load-receiving surfaces LR of the tool TL. In the figures, the horizontal load-delivering surfaces LD of the tool holder TH are shown as being downwardly facing surfaces, and the horizontal load-receiving surfaces LR of the tool are shown as being upwardly facing surfaces. In other embodiments (e.g., where the tool holder is on a lower beam), the horizontal load-delivering surface(s) LD of the tool holder is/are upwardly facing, and the horizontal load-receiving surface(s) of the tool is/are downwardly facing. Thus, the invention provides various combination embodiments wherein the shank of a tool is operatively mounted in the channel of the tool holder such that each load-delivering surface of the tool holder is generally or substantially horizontal and is carried directly against a corresponding generally or substantially horizontal load-receiving surface of the tool.
In certain embodiments, the tool holder TH is adapted for forcing the tool TL (e.g., when the tool is operatively mounted on the tool holder) against a workpiece by delivering force from the load-delivering surface(s) LD of the tool holder to the load-receiving surface(s) LR of the tool. The tool holder may move the tool into contact with the workpiece, or it may hold the tool in a stationary position while the workpiece is forced into contact with the tool, e.g., the upper or lower beam of a press brake may be moveable depending upon the press brake used. Either way, the press brake will have a pressing axis. Moreover, a tool holder is to be considered to have a pressing axis, even if it holds the tool in a stationary position during pressing operations. In some preferred embodiments, the tool holder TH is adapted for moving the operatively mounted tool TL along the pressing axis PA (shown in
In some embodiments, the tool holder is operably coupled to a press brake ram that is adapted for moving the tool holder and the operatively mounted tool together so as to force the workpiece-deforming surface of the tool against a workpiece. Preferably, the ram (which can be incorporated into, or otherwise operably coupled with, a bed BE of the press brake) is adapted for moving the tool holder TH and tool TL together in a pressing direction PD that is generally or substantially normal to the load-delivering surface(s) LD of the tool holder (e.g., in a vertical direction). In other embodiments, the tool holder is not adapted for moving the operatively mounted tool, but rather is designed for securing the tool in a stationary position during pressing operations.
Preferably, the tool holder TH has a closed configuration and an open configuration. When the tool holder TH is in its open configuration, the shank S of a press brake tool TL can be moved into and out of the tool holder's channel C. When the tool holder TH is in its closed configuration, the shank S of a tool TL mounted in the tool holder's channel C is clamped forcibly (and held rigidly) against a wall CW of the tool holder.
The tool holder TH can optionally have a moveable face plate MP, jaw, clamping pin, or the like, which preferably defines at least part of one CW′ of the confronting walls CW, CW′. In moving such a tool holder to its closed configuration, the moveable plate MP, jaw, pin, etc. desirably moves toward the other CW of the confronting walls CW, CW′. When such a tool holder moves to its open configuration, the moveable plate MP, jaw, pin, etc. desirably moves away from the other wall CW. For example, the tool holders shown in
In certain embodiments, the invention provides a press brake tool TL configured for being operatively mounted on a press brake tool holder TH (optionally one that is adapted for moving the tool, when operatively mounted on the tool holder, along a pressing axis PA). The tool TL has a shank S that is adapted for being positioned in a tool-mount channel C of the tool holder TH such that the shank when clamped forcibly between confronting walls CW, CW′ of the tool holder receives a force having a clamping component directed at least generally perpendicular to the pressing axis PA. In some of the present embodiments, the tool TL has a seating mechanism SM that is adapted for at least partially converting this force (during at least a certain period, such as an initial or middle period, of the clamping) into a seating component directed at least generally parallel to the pressing axis PA. The seating component can optionally be a generally or substantially vertical (e.g., upward) force component, and the clamping component can optionally be a generally or substantially horizontal force component. In some cases, once the tool's shank is fully clamped between the walls CW, CW′ of the tool holder, the walls CW, CW′ apply only a horizontal force on the tool's shank.
Thus, a seating mechanism SM can optionally be incorporated into the tool TL. Such embodiments extend to any press brake tool having a seating mechanism built into (and/or provided on) the tool itself. Embodiments of this nature can employ a variety of advantageous seating mechanisms. Preferably, the seating mechanism SM comprises a moveable body MB mounted on the tool TL (optionally so as to be moveable relative to a stationary portion SP of the tool's shank S). The moveable body MB in some embodiments is mounted on the tool so as to be moveable (at least in part) in both vertical and lateral directions relative to other portions (e.g., stationary portions SP) of the tool's shank S. The moveable body preferably bears forcibly against a portion (e.g., a cam surface) of the tool's shank, and thereby delivers at least the seating component of the noted force to the tool's shank, in response to the confronting walls of the tool holder being clamped forcibly on the tool's shank.
In some cases, the seating mechanism comprises a moveable body (and optionally two such moveable bodies) contacted directly by the tool holder when the confronting walls CW, CW′ clamp forcibly on the tool's shank. A moveable body of this nature can optionally have a dimension (e.g., a major dimension) that is at least ⅕th (perhaps preferably at least ¼th, perhaps more preferably at least ⅓rd, and in some cases at least ½) of the lateral width of the tool's shank S.
In certain embodiments, the seating mechanism SM includes a moveable body MB comprising a wedge member WM. The wedge member will commonly have two surfaces CS, WC that are generally opposed and oriented at an oblique angle (such as between 5 degrees and 45 degrees) relative to each other. The wedge member WM, for example, can optionally have at least one portion with a generally triangular cross-sectional configuration (optionally a cross section taken along a plane lying in both the “x” axis and the “y” axis of the tool). The wedge member WM can be mounted on the tool so that at least a portion (optionally a portion with a generally triangular cross section) of the wedge member is carried alongside a cam surface CM of the tool's shank. The wedge member preferably is adapted to (e.g., in response to the tool holder's confronting walls being clamped forcibly on the tool's shank) bear forcibly against, and cam with, a cam surface CM of the tool's shank (e.g., so as to cause relative movement of the wedge member and the cam surface CM). The cam surface CM can optionally be defined by a stationary portion (i.e., a portion that does not move relative to the load-receiving surface(s) LR of the tool and/or relative to a tip of the tool) SP of the tool's shank S. This surface CM can be offset from vertical by an angle of greater than 0 degrees but less than 30 degrees, if so desired.
When provided, the wedge member WM preferably is mounted on the tool TL so that a contact surface CS of the wedge member is adapted to be engaged by one of the confronting walls CW, CW′ of the tool holder TH when the tool's shank S is forcibly clamped between these walls CW, CW′. In some cases, the contact surface CS is generally or substantially planar. The wedge member WM desirably also includes a cam surface WC. Preferably, this surface WC of the wedge member WM is carried against the cam surface CM of the tool's shank S. In
In some embodiments, the seating mechanism SM comprises at least one rod member RM. Reference is made to
In certain preferred embodiments, the seating mechanism SM comprises two moveable bodies MB mounted at least in part on opposite sides of the tool's shank S. In some cases, these two moveable bodies MB are mounted on the tool TL such that they can both be moved (e.g., in part or in their entirety) simultaneously toward or away from each other and/or in generally opposite directions (e.g., directions that are opposite at least in terms of their lateral/x axis component, if not directly opposite). Here, both bodies MB are optionally contacted directly by the tool holder TH when the tool's shank S is clamped forcibly between the confronting walls, CW, CW′ of the tool holder. In some cases, the bodies MB define opposed contact surfaces CS (which optionally are at least generally planar) that are contacted respectively by the confronting walls CW and CW′ of the tool holder during clamping.
In one group of embodiments, the seating mechanism SM comprises two wedge members WM. Reference is made to
The seating mechanism in some embodiments can have an extended configuration and a retracted configuration. For example, the opposed contact surfaces CS of two wedge members WM may be further apart when the seating mechanism is in its extended configuration than when the seating mechanism is in its retracted configuration. Thus, when the confronting walls CW, CW′ of the tool holder TH clamp forcibly on the tool's shank S, the opposed contact surfaces CS of such wedge members WM can be forced to move closer together.
In the illustrated wedge embodiments, each of the cam surfaces CM on the tool's shank S is defined by a slanted wall. Conjointly, each of the illustrated wedge cam surfaces WC is defined by a slanted wall of a wedge member WM. These features, however, are not required. If so desired, the tool's shank S can have a cam surface CM defined by a radiused or curved wall, and/or the wedge member can have a cam surface WC defined by a radiused or curved wall.
In some cases, each cam surface CM on the tool's shank S faces generally away from a vertical axis passing through a lateral midpoint of the tool's shank (“VAD” in
As exemplified in
In some embodiments involving a rotatable member (e.g., a wheel, rotatable pin, etc.) mounted on the shank S of a press brake tool TL, the rotatable member has a diameter. This diameter can optionally be at least ⅕th the lateral width of the tool's shank, and perhaps more preferably at least ¼th of the lateral width of the tool's shank.
In
With reference to
Thus, the seating mechanism SM preferably includes at least one moveable body MB that is adapted to bear forcibly against a portion of the tool's shank (thereby delivering at least a seating component of force to the tool's shank) in response to the confronting walls of the tool holder being clamped forcibly on opposite sides of the tool's shank. Preferably, the resulting seating component is of a magnitude at least equal to the weight of the tool, such that if the tool is on the upper beam of the press brake this force component is sufficient lift the tool upwardly until the load-receiving surface(s) of the tool come(s) into direct contact with the corresponding load-delivering surface(s) of the tool holder, at which point upward movement of the tool is stopped (due to the noted engagement of the load-bearing surfaces). Several embodiments of this nature have been described.
The tool holder in
In certain embodiments, the press brake tool TL has a seating mechanism SM and a retractable safety key SK. When provided, the retractable safety key SK is adapted for engaging a safety recess SR, and/or moving into alignment with a safety shelf SCS, of the tool holder TH.
In embodiments wherein the seating mechanism SM comprises a wedge member WM, the wedge member can be provided in a variety of configurations. One configuration is shown in
As noted above, each wedge member WM preferably has a contact surface CS adapted for being engaged by the tool holder. In the illustrated wedge embodiments, the contact surface CS is a generally planar surface which, when the wedge member WM is assembled on the tool, is generally parallel to the vertical axis of the tool and/or is generally perpendicular to the load-receiving surface(s) of the tool. The contact surface CS of each wedge member WM can optionally face generally away from a “y” axis passing through a lateral midpoint of the tool's shank. Each wedge member WM preferably has a cam surface WC that is oriented at an angle relative to the vertical axis of the tool and/or relative to the contact surface CS of the wedge member. Thus, in some wedge embodiments, each wedge member WM has a contact surface CS and a cam surface WC, and these surfaces are not parallel, but rather are offset from parallel by an acute angle, which preferably is at least about 2 degrees, more preferably at least about 3 degrees, and perhaps optimally at least about 4 degrees (e.g., greater than 5 degrees). In one particular embodiment, this angle is about 13 degrees.
In connection with the neck portion WNP of the wedge member designs shown in
In
In embodiments like those exemplified by
The link member LM, when provided, can be resiliently biased toward a first position (e.g., away from the tip of the tool). For example, one or more spring members SPM can be provided to apply to the link member LM a spring force urging the link member toward its first position. This is perhaps best seen in
In
As is perhaps best seen in
The link member LM, when provided, can optionally be configured for biasing the seating mechanism SM toward its extended configuration. For example, a portion of the link member can have a ridge with an apex and sloped side surfaces diverging respectively away from the apex. The apex of such a ridge can optionally be that portion of the ridge that is furthest from the tool's tip. When such a link member moves toward its first position (e.g., due to the bias of a spring SPM), the sloped side surfaces of the ridge can engage respective lips WP of two wedge members WM. As the link member LM continues moving to its first position, the wedge members WM ride on the respective sloped side surfaces of the ridge, forcing the wedge members outwardly (e.g., away from each other). With such an arrangement, the seating mechanism SM is kept in its extended configuration unless the actuator A is operated (e.g., depressed), or the tool holder is clamp forcibly on the tool's shank, or the wedge members are otherwise forced to move inwardly toward each another. This type of arrangement tends to keep the wedge members in a default position where they are located as far from the tool's tip as is allowed by their range of movement. These features, however, are by no means required.
Reference will now be made to a group of embodiments involving a press brake tool that may or may not include a seating and/or locating mechanism. Here, the invention provides a tool having a shank that is provided with a retractable safety key. The safety key, which is moveable between an extended position and a retracted position, is operably coupled with a moveable link member such that the safety key moves from its extended position to its retracted position in response to the link member moving (e.g., axially) along a vertical axis of the tool. Exemplary embodiments including a seating and/or locating mechanism have been described. However, some embodiments in the present group do not have such a mechanism.
In the present group of embodiments, the link member can optionally comprise at least one rigid rod member. For example, a link member LM of the type shown in
Preferably, the link member is moveable between a first position and a second position, the safety key moves to its retracted position in response to the link member moving to its second position, and the safety key moves to its extended position in response to the link member moving to its first position. If so desired, the link member can be resiliently biased by a spring member SPM toward its first position. Conjointly, the link member can be operably coupled with a selectively-operable actuator. As noted above, an actuator A of this nature can be adapted for being operated at a desired time so as to overcome the resilient bias of the spring member SPM and move the link member to its second position thereby moving the safety key to its retracted position.
In certain embodiments of the present group, the safety key SK is operably coupled with the link member LM by virtue of a male projection RD of the link member that is slidably received in a slot SLT defined by the safety key. When provided, this slot can advantageously be configured to extend at an angle relative to both the “x” axis and the “y” axis of the tool. The angle of such a slot SLT can be varied as desired. In one embodiment, the slot SLT extends at an angle of about 45 degrees relative to the “x” axis of the tool. Alternatively, the slot SLT can be parallel, or substantially parallel, to the vertical axis of the tool, such that the safety key stays in an extended position as the link member moves along the vertical axis of the tool. The noted male projection can be a pin PN (e.g., extending from the link member) slidably received in the elongated slot defined by the safety key. If so desired, the safety key SK can be resiliently biased by a spring member 199 in such way that the safety key SK is urged toward its extended position. Reference is made to
The invention provides one group of embodiments wherein the tool TL has a seating mechanism and/or a locating mechanism (e.g., of any type described above) in combination with a click-in/slide-out design. Here, the tool is adapted for being mounted on a tool holder by moving the tool vertically into a channel defined by the tool holder, and for being dismounted from the tool holder by moving the tool horizontally (i.e., by sliding the tool lengthwise) out of the channel. Press brake tools of this nature are referred to herein as click-in/slide-out tools. Preferably, when these tools are mounted in the tool holder they produce an audible “click” sound upon reaching their operative position. In preferred embodiments, this sound results when the safety key(s) on the tool snaps into place in a safety slot defined by the tool holder. It is to be understood that this audible clicking is an optional feature, which is by no means required.
Some existing press brake tools are adapted for both vertical mounting (i.e., mounting by moving the tool vertically into the channel of the tool holder) and vertical dismounting (i.e., dismounting by moving the tool vertically out of this channel). Vertical dismounting has the disadvantage that it suddenly releases the full weight of the tool on the operator. This can be less than ideal in some cases, such as when particularly heavy tools are used. In contrast, the embodiments of the present group provide a tool that is not adapted for being dismounted by moving the tool vertically out of the tool holder's channel. Rather, this tool is adapted to prevent vertical dismounting.
In the present embodiment group, the tool has a retractable safety key, and the tool T is not adapted for being dismounted from the tool holder by moving the tool vertically out of the channel. Rather, the tool is adapted to prevent such vertical dismounting. In certain embodiments, this is accomplished by providing a tool that has no externally accessible actuator for retracting the safety key. Further, some embodiments provide a tool of this nature in combination with a tool holder that has no device for retracting the safety key (once it has been extended into/engaged with a safety groove/recess of the tool holder). Thus, once the tool's shank is moved into its operative position in the channel of the tool holder a press brake operator is prevented from retracting the safety key and removing the tool vertically from the tool holder. As a result, the tool T is designed to prevent vertical removal and to only allow removal by sliding the tool lengthwise (i.e., longitudinally) out of the channel C of the tool holder. Further details of click-in/slide-out tools are described in U.S. Pat. No. 7,021,116, the entire contents of which are incorporated herein by reference.
The invention provides a variety of methods for operating a press brake. Some embodiments, for example, provide a method of mounting a press brake tool TL on a tool holder TH of a press brake having a pressing axis. The tool holder has a tool-mount channel C bounded by first and second confronting walls CW, CW′. Here, the first confronting wall CW′ is moveable at least in part toward the second confronting wall CW. The tool holder TH, in some embodiments, has at least one load-delivering surface LD and is adapted for moving the tool TL when operatively mounted on the tool holder along the pressing axis PA. The tool TL has a shank S and at least one load-receiving surface LR. The tool TL in the present method also has a seating mechanism SM. The method comprises positioning the tool's shank S in the tool-mount channel C and moving the first confronting wall CW′ at least in part toward the second confronting wall CW thereby forcibly clamping the tool's shank between the confronting walls CW, CW′ so as to deliver to the shank a force that is at least partially converted into a seating component directed at least generally parallel to the pressing axis PA. The seating component of this force moves the tool TL relative to the tool holder TH so as to bring the load-receiving surface LR of the tool into engagement with the load-delivering surface LD of the tool holder.
The seating mechanism SM in the present method optionally comprises a moveable body MB mounted on the tool TL so as to be moveable relative to a portion (e.g., a stationary portion SP) of the tool's shank S, such that forcibly clamping the tool's shank between the confronting walls CW, CW′ causes the moveable body to bear forcibly against a portion of the tool's shank thereby delivering at least the seating component of the force to the tool's shank (and desirably moving the tool in the manner described above).
The moveable body MB in the present method can optionally be a wedge member WM carried (at least in part) alongside a cam surface CM of the tool's shank S. Here, forcibly clamping the tool's shank S between the confronting walls CW, CW′ causes the wedge member WM to bear forcibly against, and cam with, the cam surface CM of the tool's shank so as to cause relative movement of the wedge member and the cam surface CM.
In the present method, the seating mechanism SM can optionally comprise two moveable bodies MB mounted at least in part on opposite sides of the tool's shank S. The two moveable bodies MB can be wedge members, if so desired. Forcibly clamping the shank S of such a tool TL between the confronting walls CW, CW′ of the tool holder TH causes the wedge members WM to bear forcibly against, and cam with, respective cam surfaces CM on the tool's shank. As noted above, this clamping can optionally cause opposed contact surfaces of the two wedge members to move closer together.
In some of the present method embodiments, the moveable body MB is a wheel member WH and forcibly clamping the tool's shank S between the confronting walls CW, CW′ of the tool holder TH involves the wheel member engaging one of the confronting walls thereby causing the wheel to rotate.
In some embodiments of the present method, the tool holder TH defines a safety groove SR open to the tool-mount channel C, the tool TL further comprises a retractable safety key SK, and the method includes moving the tool's safety key into the tool holder's safety groove.
When provided, the safety key SK can optionally be operably coupled with a moveable link member LM such that the safety key moves along a lateral axis of the tool TL in response to the link member moving along a vertical axis of the tool. In some methods involving a press brake tool TL of this nature, moving the tool's safety key SK into the tool holder's safety groove SR involves the safety key moving along the lateral axis of the tool in response to the link member moving along the vertical axis of the tool.
In some embodiments of the present method wherein the tool TL includes both a retractable safety key SK and a link member LM, the safety key SK is moveable between an extended position and a retracted position, the link member LM is moveable between a first position and a second position, the safety key moves to its retracted position in response to the link member moving to its second position, the safety key moves to its extended position in response to the link member moving to its first position, and moving the tool's safety key into the tool holder's safety groove SR involves the safety key moving to its extended position in response to the link member moving to its first position.
In
In some of the present ball member embodiments, the ball member BA has a diameter that is at least about one-fifth of the lateral width of the tool's shank, and perhaps more preferably is at least about one-fourth the lateral width of the tool's shank.
Thus, the tool TL can be provided with a seating mechanism comprising one or more moveable bodies (e.g., wedge members, rod members, wheel members, and/or ball members) of various different designs. In one group of embodiments, the tool holder includes a moveable body having at least one part (optionally the whole moveable body) comprising a polymer, optionally with a filler. In some of these embodiments, the moveable body consists essentially of the polymer and the filler. One useful polymer is nylon, such as nylon 66. Torlon or ultra high molecular weight polyethylene may also be suitable. If so desired, the polymer can comprise a filler that provides increased hardness, increased durability, and/or decreased flexibility. Glass fibers are an advantageous filler. One embodiment involves a nylon polymer with a glass filler (e.g., nylon 66 with 20% glass filler). Other useful fillers may include fumed silica or talc. When provided, each moveable body comprising polymer can be produced by conventional molding methods. Suitable polymer components can also be obtained commercially from companies like The ProtoMold Company (Maple Plain, Minn., U.S.A.).
In certain embodiments involving a moveable body MB comprising a polymer, the moveable body comprises (e.g., optionally is) a wedge member WM at least a portion of which is carried alongside a cam surface CM of the tool's shank. Here, the wedge member WM comprises the polymer and is adapted to bear forcibly against, and cam with, the cam surface CM so as to cause relative movement of the wedge member and the cam surface. The cam surface can optionally be defined by a slanted and/or radiused wall of the tool's shank. Seating mechanisms of this nature are described above in more detail. Some embodiments provide the cam surface CM in the form of metal (e.g., steel) over which a coating is provided. The coating, for example, can comprise nitrogen and/or carbon (e.g., it can be a nitride and/or nitrocarbide enhancement, as described below).
Certain embodiments involving polymer technology provide a seating mechanism that includes two moveable bodies MB mounted at least in part on opposite sides of the tool's shank. The two moveable bodies, for example, can be wedge members WM that bear forcibly against, and cam with, respective cam surfaces CM on the tool's shank in response to the confronting walls of the tool holder clamping forcibly on opposite sides of the tool's shank. In the present embodiments, each wedge member WM comprises the polymer. The seating mechanism in some of these embodiments has an extended configuration and a retracted configuration, where opposed contact surfaces CS of the two wedge members are further apart when the seating mechanism is in its extended configuration than when the seating mechanism is in its retracted configuration, and where the opposed contact surfaces of the two wedge members move closer together in response to the confronting walls of the tool holder clamping forcibly on the opposite sides of the tool's shank. Each cam surface CM can optionally be defined by a slanted and/or radiused wall of the tool's shank. Seating mechanisms of this nature are described above in more detail.
The invention provides a number of embodiments wherein the seating mechanism comprises at least one moveable body formed of one material while the tool's shank (or at least a cam surface thereof and/or a stationary portion thereof) is formed of another (different) material. The seating mechanism, for example, can include a moveable body comprising a polymer while the tool's shank (or at least a cam surface thereof, and/or a stationary portion thereof, optionally a major portion thereof) comprises metal (e.g., steel).
In one group of embodiments, the tool TL is provided with a coating 907 over at least one surface. In some embodiments of this group, a coating 907 is provided on a cam surface CM (e.g., a surface against which a moveable body MB of the seating mechanism is adapted to cam during clamping of a tool holder on the tool's shank) of the tool's shank. Here, the cam surface CM is not a surface that comes into contact with the tool holder or the workpiece during operation. The coating 907, however, can be provided on such a cam surface to minimize or reduce any binding that may otherwise occur between the moveable body or bodies of the seating mechanism and the cam surface(s) CM of the tool's shank. Reference is made to
In some embodiments, the tool TL is provided with a coating 907 over at least a majority of its shank's surface area (optionally over substantially all of its surface area, over substantially all of its surface area excluding at least some internal surfaces, over substantially all of its surface area including internal surfaces, over substantially all of its surface area excluding surfaces of a safety key and/or link member, etc.). The coating can be provided to increase surface hardness, to increase lubricity, and/or to otherwise protect against wear, corrosion, sticking, and/or galling.
When provided, the coating can optionally be a dry lubricant coating. For example, the coating can comprise nickel (e.g., nickel alloy) and/or a low friction polymer. In some cases, the coated surface has one or more of the following features: (i) a coefficient of static friction below 0.35, below 0.3, or even below 0.2; (ii) a coefficient of dynamic friction below 0.3, below 0.25, below 0.18, or even below 0.1. Useful dry lubricant coatings are available commercially from, for example, General Magnaplate Corporation (Linden, N.J., USA) and Poeton Industries, Ltd. (Gloucester, England). As one example, the coating can be a NEDOX® coating.
In one subgroup of the present embodiments, the coating comprises a nitride and/or a carbide. One commercially available nitride coating is the Nitrex® coating, which is a high endurance surface enhancement available commercially from Nitrex, Inc. (Aurora, Ill., USA). Particularly useful nitriding and nitrocarburizing enhancements are described in U.S. Pat. No. 6,327,884, the entire teachings of which are incorporated herein by reference.
Nitriding and nitrocarburizing processes are known in the field and need not be described in great detail. Reference is made to U.S. Pat. Nos. 4,790,888 and 4,268,323, the teachings of which regarding such enhancements are incorporated herein by reference. The latter patent refers to the use of a fused salt bath to enable nitrogen and carbon to diffuse into the surface of a steel piece suspended in the bath to form a carbonitride case. Reference is made also to U.S. Pat. No. 5,234,721 (referring to methods of forming carbonitride coatings), the teachings of which regarding such coatings are incorporated herein by reference.
Nitriding processes, both plasma (ion) nitriding and liquid nitriding, are described in detail in the ASM Handbook prepared under the direction of the ASM International Handbook Committee, Revised vol. 4: Heat Treating, pp. 410-424 (1994), the teachings of which concerning nitriding enhancements are incorporated herein by reference. Plasma or ion nitriding involves the use of glow discharge technology to provide nascent nitrogen to the surface of a heated steel part. Here, the part is subjected to a nitrogen plasma in a vacuum chamber. Nascent nitrogen diffuses into the surface of the part to form an outer “compound” zone containing γ (Fe4N) and ε(Fe2,3N) intermetallics, and an inner “diffusion” zone which may be described as the original core microstructure with some solid solution and precipitation strengthening. Liquid nitriding involves immersing a steel part in a molten, nitrogen-containing fused salt bath containing cyanides or cyanates, e.g., NaCN or NaCNO. Tool components can be enhanced by liquid nitriding through a wide variety of commercial coating manufacturers, such as Metal Treaters Inc. of St. Paul, Minn., USA.
While preferred embodiments of the present invention have been described, it is to be understood that numerous changes, adaptations, and modifications can be made to the preferred embodiments without departing from the spirit of the invention and the scope of the claims. Thus, the invention has been described in connection with specific embodiments for purposes of illustration. The scope of the invention is described in the claims, which are set forth below.
The present application claims priority to provisional US patent application filed Jun. 10, 2005 and assigned Ser. No. 60/689,380, the disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60689380 | Jun 2005 | US |
