STRIPPER ASSEMBLIES AND COMPONENTS THEREOF FOR MULTI-TOOL

PUNCH ASSEMBLIES

TECHNICAL FIELD [01] The present invention pertains to multi-tool punch tool assemblies and more particularly to stripper assemblies thereof.

BACKGROUND

[02] Multi-tool punch assemblies are known in the art to provide a selection from a plurality of punch tools at a single station of a punch press. Multi-tool punch assemblies typically employ a punch guide that is adapted to move each punch tool, of the plurality of punch tools carried by the guide, into and out from a working position, for example, via rotation about its own axis within a turret press station in which the guide is mounted. [03] Those skilled in the art are familiar with the stripping function that is fundamental to the operation of punch assemblies in order to ensure that punched material is separated from the punch tip; several types of stripper assemblies for mounting onto multi-tool punch guides have been previously disclosed. However, there is still a need for new stripper assemblies, and components thereof, that can facilitate more efficient and simpler methods for assembling multi-tool punch assemblies.

BRIEF DESCRIPTION OF THE DRAWINGS

[04] The following drawings are illustrative of particular embodiments of the present invention and therefore do not limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements.

[05] Figure 1 is perspective view of a multi-tool punch assembly for use in a punch press, according to some embodiments of the present invention.

[06] Figure 2 is an exploded perspective view of a portion of the multi-tool punch assembly shown in Figure 1 , according to some embodiments. [07] Figure 3 is a perspective view of a plate of the assembly shown in Figures

1-2, according to some embodiments of the present invention. [08] Figure 4 is a perspective view of a plate for a stripper assembly, according to some alternate embodiments of the present invention. [09] Figure 5 is a block diagram for an exemplary information storage device and reader which may be employed by embodiments of the present invention. [10] Figure 6 is a perspective view of an alternative embodiment of a stripper assembly. [11] Figure 7 is a flow chart outlining some methods of the present invention.

DETAILED DESCRIPTION [12] The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides practical illustrations for implementing exemplary embodiments of the present invention. Examples of constructions, materials and dimensions are provided for selected elements, and all other elements employ that which is known to those of skill in the field of the invention. Those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized. [13] Figure 1 is perspective view of a multi-tool punch assembly for use in a punch press, according to some embodiments of the present invention; and

Figure 2 is an exploded perspective view of a portion of the multi-tool punch assembly shown in Figure 1. The assembly of Figures 1 and 2 may be a rotary indexing type, which may be mounted, for example, in an upper turret of a rotary turret punch press in conjunction with a corresponding die set mounted in a lower turret of the press. It should be noted that embodiments of the present invention may be employed by other types of multi-tool punch assemblies, which are compatible for mounting in

alternative types of ram-driven presses, for example, a Trumpf-style press, known to those skilled in the art, that brings tool assemblies, held in a cartridge, one at a time from a rail into a working position of the press. Figures 1 and 2 illustrate the assembly including a punch holder, or guide 160, which carries a plurality of punch tools 51 , 52, 53, and a stripper assembly 100, which includes a plate 110 and plurality of strippers 101 , 102, 103; each stripper 101 , 102, 103 includes a punch port 151 , 152, 153 through which a corresponding punch tool 51 , 52, 53 extends when activated. [14] According to the illustrated embodiment, individual stripper members, which are approximately coplanar with plate 110, form each stripper 101 , 102, 103, when reversibly coupled to plate 110. Figure 2 further illustrates plate 110 including a plurality of grippers 25 for reversibly coupling members 101 , 102, 103; and Figure 1 shows each gripper 25 extending about a perimeter of a corresponding stripper member 101 , 102, 103.

Grippers 25 will be described in greater detail below, in conjunction with Figure 3.

[15] Figure 2 further illustrates a surface 26 of punch guide 160 including flanges 216 and recesses 246 providing for a quick-release-type engagement with mating features of plate 110. Figure 3 is a perspective view of plate 110 illustrating a plurality of resilient members 24 protruding from a first face 111 thereof, for engagement within recesses 246, and illustrating a plurality of grooves 21 located about a perimeter of first face 111 , for engagement with flanges 216. According to the illustrated embodiment, plate 110 is reversibly mounted to punch guide 160 by, first, bringing first face 111 into close proximity with surface 26 of guide 160, and, then, by rotating plate 110, about a centerline axis 10 (Figures 1-2), to engage grooves 21 with flanges 216 and to simultaneously bring protruding resilient members 24 into a quick-release-type engagement with recesses 246. With reference to Figures 2-3, it may be appreciated that engagement of grooves 21 with flanges 216 provides a holding force in a direction approximately parallel to centerline axis 10, while resilient members 24,

engaged within recesses 246, provide a holding force in a direction approximately orthogonal to axis 10, for example, preventing rotation of plate 110 about axis 10.

[16] Preferably, each of stripper members 101 , 102, 103 is inserted into a corresponding gripper 25 of plate 110 after plate 110 is mounted to guide

160, but the invention is not so limited, and members 101 , 102, 103 may be inserted prior to mounting, according to alternate embodiments. Figures 2- 3 further illustrate each gripper 25 formed by a slot extending through plate 110 from first face 111 to a second face 112. Figure 3 shows each slot formed by a sidewall 35 that is terminated at opposite ends thereof by a pair of reliefs 350, wherein each relief 350 terminates a corresponding end of sidewall 35 and the ends are spaced apart by a gap. Sidewalls 35 are resilient to provide an adequate gripping force about each member 101 , 102, 103, and, according to some embodiments, are sized to extend within an optional groove 15 of each member 101 , 102, 103; each relief 350 allows an adjacent or flexing portion 355 of sidewall 35 to flex and thus spread for insertion, as well as subsequent withdrawal, of the corresponding stripper member 101 , 102, 103. The gripping force of grippers 25 is sufficient to hold stripper members 101 , 102, 103 in the proper position, as shown in Figure 1 , during punching operations in a punch press, without a need for additional retaining forces that can complicate the multi-tool punch assembly, such as from a ring component extending about a perimeter of plate 110, or from an extension of punch tools 51 , 52, 53 through corresponding ports 151 , 152, 153 of members 101 , 102, 103. Grippers 25 may be described as providing a secure, yet reversible and quick-release-type engagement for stripper members 101 , 102, 103 in order to facilitate simple and efficient exchange of any of stripper members 101 , 102, 103 for an alternative stripper member, without having to disassemble other components of the multi-tool assembly. [17] Stripper members 101 , 102, 103 may be inserted into the corresponding gripper 25 axially (in a direction approximately parallel to axis 10), or radially, per arrows A of Figure 2, either before or after mounting plate 110

to punch guide 160. With reference to Figure 1 , when stripper members 101 , 102, 103 are inserted into grippers 25, an exposed surface of each stripper member 101 , 102, 103 may be recessed with respect to second face 112 of plate 110, flush with second face 112 of plate 110, or protruding from second face 112 of plate 110.

[18] It should be noted that the present invention is not limited to any particular number of tools held in punch guide 160 and, according to alternate embodiments, plates for stripper assemblies are compatible with guides that can hold a fewer or a greater number of tools, than that which is illustrated in Figure 2. For example, inventive plates for stripper assemblies may accommodate three tools, four tools, five tools, eight tools, ten tools, sixteen tools, twenty tools, twenty-four tools, and thirty tools, these numbers of tools being typical in the industry for multi-tool assemblies. [19] Figure 4 is a perspective view of another plate 710 which is configured to reversibly receive a greater number of stripper members than the number received by plate 110, in order to provide a stripper assembly for a multi- tool punch guide that has an increased capacity to carry a greater number of tools than punch guide 160. Figure 4 illustrates plate 710 including a first plurality of grippers 75 and a second plurality of grippers 750; grippers

75 and 750 are each formed by a slot extending through plate 710 from a first face 711 to a second face 712, similar to grippers 25 of plate 110. Like grippers 25, the slots that form grippers 75 and 750 are each formed by a sidewall 85 that has opposite ends spaced apart by a gap, and wherein each end is terminated by a relief 850 that allows an adjacent or flexing portion 855 of sidewall 85 to flex and thus spread for insertion, as well as subsequent withdrawal, of a corresponding stripper member. According to the illustrated embodiment, the gap of each of the first plurality of grippers 75 faces away from a centerline axis 70 of plate 710, similar to each of grippers 25 of plate 110, but the gap of each of the second plurality of grippers 750 faces in an opposite direction, toward axis 70.

[20] Figure 4 further illustrates plate 710 including grooves 71 , which are located about a perimeter of first face 711 , and resilient members 74, which protrude from first face 711. According to the illustrated embodiment, resilient members 74 engage within recesses of a corresponding punch guide, similar to the previously described engagement of members 24, of plate 110, within recesses 246 of guide 160, when grooves 71 of plate 710 engage with flanges of the corresponding punch guide. Like plate 110, plate 710 is reversibly mounted to the corresponding punch guide by, first, bringing face 711 into close proximity with a surface of the guide that includes the mating flanges and recesses, and, then, by rotating plate 710, about centerline axis 70, to engage grooves 71 with the flanges and to simultaneously bring resilient members 74 into quick-release-type engagement with the recesses. [21] According to preferred embodiments of the present invention, stripper plates, for example, either of plates 110, 710, are formed from a relatively stiff, yet resilient polymer material, examples of which include, without limitation, Nylon 66, such as Zytel 103 HSL, Polyethylene terephthalate (PET), such as Rynite 530-BK503, and an acetal resin engineering plastic, such as Delrin 100KM NCOOO, which are all available from DuPont®. Stripper members that are received by either of plates 110, 710, for example, stripper members 101 , 102, 103 (Figure 2), may be formed from tool steels, such as 4140, M2 or D2, known to those skilled in the art, or from any of the aforementioned exemplary polymer materials. An embodiment of either of plates 110 and 710, which at least includes a polymer forming the respective second face 112, 712, is not as likely, as one formed entirely from metal, to mar a surface of a workpiece, if there is any contact between plate 110, 710 and the workpiece during punching operations. Furthermore, if a slug from the workpiece is inadvertently pulled up with one of the punch tools, for example, one of punch tools 51 , 52, 53, it may become embedded in second face 112 of plate 110 that is formed by a polymer, and, thus, be less likely to significantly mar the workpiece; also, a polymer material, which forms either part of or all of

plate 110, 710, may absorb shock and vibration that can cause unwanted noise and/or damage to components of the corresponding multi-tool punch assembly.

[22] For those embodiments of plates 110, 710 formed from a resilient polymer, protruding resilient members 24, 74 and/or flexing portions 355, 855 of sidewalls 35, 85 may be integrally formed with plate 110, 710. Alternatively, plates 110, 710 may be formed from a material that is distinct from that which forms resilient members 24, 74 and flexing portions 355, 855, for example, a stiffer and less resilient material such as a hardened metal, like aircraft grade aluminum or titanium. Exemplary dimensions, for either of plates 110, 710, wherein the plate is wholly formed from Nylon 66, are as follows: an average thickness of plate 110, 710 ranges from approximately 1/16 inch to approximately 5/16 inch (thickness in direction approximately parallel to axis 10, 70); a length L of flexing portions 355, 855 ranges from approximately 1/8 inch to approximately 3/8 inch; and a maximum thickness of flexing portions 355, 855 is between approximately % inch and approximately 5/16 inch, while a minimum thickness thereof is between approximately 1/16 inch and approximately 1/8 inch (thicknesses in the flexing direction, approximately orthogonal to axis 10, 70). [23] According to another aspect of the present invention, stripper assembly 100 includes an information storage device to help to manage implementations of various punch tools, for example, tools 51 , 52, 53 (Figure 2). With reference to Figure 3, such an information storage device 310 is shown coupled to first face 111 of plate 110. According to some embodiments of the present invention, information storage device 310 is adapted to store punch tool identification/characterization information, and/or punch tool prior usage information, and/or punch tool maintenance information. Storage device 310 may store tool information as a coded data pattern, for example, in the form of a bar code tag, but is preferably programmable, including a read/write memory, and has a capacity for wireless communications, for example, being a type of radio-frequency (RF) identification tag that includes an antenna and an integrated circuit for

storing and processing information and for modulating and demodulating an RF signal. Figure 5 is a block diagram for such an information storage device 310, and for an associated reader 520.

[24] Figure 5 illustrates storage device 310 including a read/write memory 531 linked to a transceiver 533 for sending information to, and receiving information from reader 520. Figure 5 further illustrates storage device 310 including a controller 532, for example, a processor unit, in communications with both read/write memory 531 and transceiver 533 to perform reprogramming operations. According to the illustrated embodiment, reader 520, which includes a processor 521 and a transceiver 523, is linked to a press control center 510, and to an auxiliary storage 570 for data collected from information storage device 310 and for information sent to information storage device 310 from press control center 510. Examples of storage device 310 and reader 520, in conjunction with press control center 510 and auxiliary storage 570, which may be employed by embodiments of the present invention, are described in detail in U.S. Patent 6,047,579, which is hereby incorporated by reference in its entirety. [25] Returning now to Figures 1-3, it may be appreciated that information storage device 310, being mounted to first face 111 of plate 110, is contained between plate 110 and surface 26 of punch guide 160, when plate 110 is mounted to guide 160, and that wireless data transmission therefrom is not hindered by the containment. Thus, during punching operations, when the complete multi-tool punch assembly is mounted in a punch press, storage device 310 is enclosed, within the assembly, for protection from the environment of the press. In addition to protecting information storage device 310 from exposure to processing materials of the press, such as lubricants and coolants, if at least portions of plate 110 are formed from a resilient polymer, as mentioned above, plate 110 can further protect storage device 310 by absorbing shock and vibration that may result when any of the punch tools form the workpiece, and when stripper members 101 , 102, 103 and/or plate 110 contact the workpiece during punching operations.

[26] With further reference to Figure 1 , a passive information storage device, being embodied as a bar code tag 13, is shown attached to second face 112 of plate 100; tag 13 may contain encoded data corresponding to permanent identification information associated with plate 110. According to the illustrated embodiment, tag 13 is exposed, when plate 110 is mounted to guide 160, in order that a bar code reader may obtain the information therefrom, and is not as susceptible to punch press environmental damage as information storage device 310 would be if similarly exposed. [27] Figure 6 is a perspective view of an alternative embodiment of a stripper assembly 400. Figure 6 illustrates assembly 400 including a plate 410 having a plurality of strippers 401 , 402, 403 integrally formed therein, and wherein each stripper 401 , 402, 403 includes a punch port 451 , 452, 453. According to some preferred embodiments of stripper assembly 400, punch ports 451 , 452, 453 are formed, after plate 410 is initially mounted to a punch guide, for example, punch guide 160 (Figures 1-2), by tools 51 , 52, 53, which are mounted in guide 160 and driven by a press in which the entire multi-tool punch assembly is mounted. [28] Like plate 110, previously described, plate 410 may be mounted to punch guide 160 by bringing a first face 411 thereof into close proximity with surface 26 of guide 160 and rotating plate 410, about a centerline axis 40 to engage grooves 21 with flanges 216 and to simultaneously engage protruding resilient members 24 with recesses 246. Also, like plate 110, plate 410 may be formed, all, or in part, from a resilient polymer material. Figure 6 further illustrates stripper assembly 400 including information storage device 310, as previously described, which is coupled to first face 411 of plate 410, so that when plate 410 is mounted to guide 160, storage device 310 is contained between plate 410 and punch guide surface 26. [29] Figure 7 is a flow chart outlining some methods of the present invention related to the information storage aspect thereof. Figure 7 illustrates an initial step 601 wherein strippers are formed in a plate of a stripper assembly; formation of strippers may be performed by inserting individual

stripper members into a the plate, for example, members 101 , 102, 103 into grippers 25 of plate 110, as previously described in conjunction with Figures 1-3, or by punching ports into the plate, for example, ports 451 , 452, 453, as previously described in conjunction with Figure 7. In a subsequent step 603, punch tool information is entered into an information storage device, for example, storage device 310, which is coupled to the plate of the stripper assembly; the information may be dictated by the formed strippers and includes information identifying a geometry and unique position of each tool, for example, tools 51 , 52, 53 (Figure 2), within a punch guide to mate up with the corresponding punch port 151 , 152, 153.

The punch tool information may further include a length of each selected punch tool, material properties thereof, a usage history thereof, and/or a maintenance history thereof; this additional information may be collected from an information storage device, which is coupled to each punch tool and is similar to device 310, as previously described.

[30] The stripper assembly may be mounted to the punch guide, as previously described in conjunction with Figures 1-3, either before or after each of the punch tools is mounted into the corresponding unique position in the punch guide; and the strippers may be formed in the stripper assembly plate either before or after the stripper assembly plate is mounted to the punch guide. According to some alternate embodiments of the present invention, step 603 precedes step 601. [31] Figure 7 further illustrates a step 605, following step 603, in which the storage device transfers the information to a control center of the press, for example, via wireless RF transmission to reader 520, which is linked to press control center 510, as previously described in conjunction with Figure 5. The control center of the press uses the transferred information to control punching operations, which are carried out by the punch tools mounted in the guide of the multi-tool punch assembly, which has been mounted in the press. The multi-tool punch assembly may be mounted in the press at any time following step 601 , unless the stripper assembly plate, which is mounted to the guide, initially includes no strippers and the

strippers are to be formed by punching, as previously described in conjunction with Figure 6. [32] After a workpiece has been processed in the punch press, the control center of the press transfers, back to the information storage device of the corresponding stripper assembly plate, per step 607, data concerning the operation of each punch tool, for example, punching frequency, forces applied, die penetration, jobs processed, index angle, etc... Thus, the punch tool information, which is contained in the information storage device, is updated to reflect the usage history of each punch tool mounted in the corresponding multi-tool punch assembly; the updated information may be subsequently transferred back to the control center of the same press, or another press, when the multi-tool assembly is employed again to process another workpiece. [33] In the foregoing detailed description, the invention has been described with reference to specific embodiments. However, it may be appreciated that various modifications and changes can be made without departing from the scope of the invention as set forth in the appended claims.