Abstract:
Method and Apparatus for fabricating a spacer frame for use in an insulating glass unit. One of a multiple number of possible spacer frame materials is chosen for the spacer frame. An elongated strip of the material is moved to a notching station where notches are formed at corner locations. The character of the notches is adjusted based on the selection of the metal strip material and more particularly to achieve bending of the material hi an repeatable, straightforward manner. Better control over the notching process is also achieved by exhaust row control of a double acting cylinder. A positioning spacer achieve very accurate side to side positioning of a die and anvil to precisely notch and deform the metal strip. Downstream from the notching station the metal strip is to bent into a channel shaped elongated frame member having side walls. Further downstream leading strip of channel shaped material is severed or separated from succeeding material still passing through the notching and bending station.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority from U.S. Provisional patent application Ser. No. 61/364,848 having a filing date of Jul. 16, 2010 which is incorporated herein by reference for all purposes. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a method and apparatus for fabricating a spacer frame for use in making a window or door. 
       BACKGROUND 
       [0003]    Insulating glass writs (IGUs) are used in windows and doors to reduce heat loss from building interiors during cold weather. IGUs are typically foamed by a spacer assembly sandwiched between glass lites. A spacer assembly has a frame structure extending peripherally about the insulating glass unit. A sealant material bonds the glass lites to the frame structure and a desiccant for absorbing atmospheric moisture within the unit, trapped between the lites. The margins or the glass lites are flush with or extend slightly outwardly from the spacer assembly. The sealant extends continuously about the frame structure periphery and its opposite sides so that the space within the IGUs is hermetic. 
         [0004]    U.S. Pat. No. 5,361,476 to Leopold discloses a method and apparatus for making IGUs wherein a thin flat strip of sheet material is continuously formed into a channel shaped spacer frame having corner structures and end structures, the spacer thus formed is cut off, sealant and desiccant are applied and the assemblage is bent to form a spacer assembly. 
         [0005]    U.S. Pat. No. 7,610,681 to Calcei et al. (hereinafter “the ‘681 Patent”) concerns spacer frame manufacturing, equipment wherein a stock supply station includes a number of rotatable sheet stock coils, an indexing mechanism for positioning one of the coils, and an uncoiling mechanism. Multiple other processing stations act on the elongated strip of sheet stock uncoiled from the stock supply station. The disclosure of the &#39;681 Patent is incorporated herein by reference. 
         [0006]    U.S. Pat. No. 7,448,246 to Briese at al. (hereinafter “the 246 Patent”) concerns another spacer frame manufacturing system. As discussed in the &#39;246 Patent, spacer frames depicted are initially formed as a continuous straight channel constructed from a thin ribbon of stainless steel material e.g., 304 stainless steel having a thickness of 0.006-0.010 inches. As noted, other materials such as galvanized, tin plated steel, or aluminum can he used to construct the spacer frame. The disclosure of the &#39;246 Patent to Briese et al. is also incorporated herein by reference. Typical thickness for these other materials range from 0.006 to 0.025 inches in thickness. 
       SUMMARY 
       [0007]    A disclosed system and method fabricates window components such as a spacer frame used in making an insulating glass unit. One of a multiple number of possible materials is chosen from which to make the window component. An elongated strip of the chosen material is moved to a notching station where notches are formed at corner locations. The character of the notches is adjusted based on the selection of the strip material and more particularly to achieve bending of the material at the corner locations in an repeatable, attractive manner. Downstream from the notching station in the example of a spacer frame, the strip is bent into a channel shaped elongated frame member having side walls. Further downstream a leading portion of channel shaped material that forms a forwardmost spacer frame is severed or separated from succeeding material still passing through the notching and bending stations. 
         [0008]    Different alternative example embodiments for controlling the quality of the corners produced at the notching station are disclosed. It is important to apply sufficient force to the weakened (coined) zone of a corner to facilitate proper folding characteristics. Too little force can result in the corner not folding properly or at all, and too much force can result in the weakened (coined) zone of a corner to become completely removed, or clipped out, from the elongated strip. 
         [0009]    In one example embodiment the notching station punches corner locations using dies on opposite sides of the strip stock. A first adjustable die assembly includes a first die mounted for back and forth movement perpendicular to a strip stock path of travel to accommodate different width strip stock. A second die assembly includes a second die is positioned on an opposite side of the strip stock path of travel from the first die. A ram assembly controllably drives the dies into engagement with the strip stock to form a corner location. Accurate positioning of the first die is performed by fixing a reference surface in a position based on a width of the strip stock and trapping an adjustable width spacer element between the reference surface and a die assembly surface of the adjustable die assembly that is generally parallel to the reference surface. 
         [0010]    In one specific example embodiment, the adjustable width spacer has a body portion that includes first and second outer cylindrical surfaces having a stepped region. A sleeve fits over as small diameter cylindrical surface of the body portion. One or more annular spacers define a spacing between one end of the sleeve and an opposite end of the body portion when abutting the sleeve and the stepped region of the body. This spacer is quite accurate in positioning the first or moveable die and does this positioning without any racking or misalignment of the spacer. This in turn results in reduced friction in the notching station and increases the consists of corner formation. For example, guides which support and define the movement of the ram assembly with respect to the strip stock are located in prescribed positions reducing friction and misalignment. 
         [0011]    In accordance with another example embodiment, a corner forming station has a dual acting fluid powered actuator for moving a die into contact with a surface of the strip stock at controlled corner locations along a length of the snip stock. The fluid actuator includes a variable release valve far relieving pressure at a controlled rate in one chamber while fluid is pressurizing a second chamber of the actuator. By regulating the release of the fluid from one pressurized chamber more consistency in corner formation is achieved regardless of the material passing through the corner fanning station. 
         [0012]    These and other features of the disclosure will become more fully understood by a review of a description of an exemplary system when reviewed in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The foregoing and other features and advantages of the present disclosure will become apparent to one skilled in the art to which the present disclosure relates upon consideration of the following description of the disclosure with reference to the accompanying drawings, wherein like reference numerals refer to like parts unless described otherwise throughout the drawings and in which: 
           [0014]      FIG. 1  is a perspective view of an insulating glass unit; 
           [0015]      FIG. 2  is section view as seen from the plane  2 - 2  of  FIG. 1 ; 
           [0016]      FIGS. 3 and 4  are top and side views of a spacer frame (prior to being folded into a closed-multi-sided frame) that forms part of the  FIG. 1  insulating glass unit; 
           [0017]      FIG. 5  is a schematic depiction of a production line for use with the invention; 
           [0018]      FIG. 6  is a perspective view of a stock supply station; 
           [0019]      FIG. 7  is an elevation view of a corner stamping unit that forms part of a punch station; 
           [0020]      FIG. 8  is a perspective view of a stop for limiting movement of a die that deforms a metal strip passing through the corner stamping unit; 
           [0021]      FIG. 9  is a perspective view of an alternate stop suitable for use with the corner stamping unit; 
           [0022]      FIG. 10  is side elevation view of the alternate stop of  FIG. 9 ; 
           [0023]      FIG. 11  is a perspective view of a punching station baying side by side stamping units that are actuated by a controller based on the type of material of the strip material passing through the stamping unit; 
           [0024]      FIG. 12  is a plan view a portion of an elongated metal strip for use in forming a spacer frame; 
           [0025]      FIGS. 13, 13A, 14, and 14A  are perspective views of a die set including a punching the and a deformation die; 
           [0026]      FIG. 15  is a side elevation view and  FIG. 15A  is a partially sectioned side view of a corner stamping unit having spacer elements that accurately position a strip with relation to a die as the strip moves into position for stamping; 
           [0027]      FIG. 16  is a perspective view of a crimp station; 
           [0028]      FIG. 17  is a front elevation view of the crimp station; 
           [0029]      FIG. 18  is a side elevation view of the crimp station; 
           [0030]      FIG. 19  is a section view of a punch station having a capability for moving a set of dies back and forth to accommodate different width stock; 
           [0031]      FIG. 20  is a perspective view of a crimping finger; 
           [0032]      FIG. 21  is a perspective view of a section of strip stock after it has been passed through a roil former; 
           [0033]      FIGS. 22 and 22A  are a pneumatic schematics showing solenoid valves that selectively supply air to air actuated cylinders at the punch station; 
           [0034]      FIG. 23  is a schematic showing two air actuated cylinders for forming corners that having a flow control valve that limits a rate of air escaping a pressurized chamber of the cylinder; 
           [0035]      FIG. 24  is a perspective view of a spacer assembly used in relatively positioning die and avil assemblies at a corner forming station; 
           [0036]      FIG. 25  is an elevation view of the spacer assembly shown in  FIG. 24 ; 
           [0037]      FIG. 26  is a section view of the spacer assembly shown in  FIGS. 24 and 25 ; 
           [0038]      FIG. 27  is a perspective view of a die assembly for notching and stamping or coining a corner location of a spacer frame; 
           [0039]      FIG. 28  is a perspective view of a flow control valve that forms part of the schematic of  FIGS. 22 and 23 ; and 
           [0040]      FIG. 29  is a side elevation view showing support for moveable die and anvil supports. 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    Referring now to the figures generally wherein like numbered features shown therein refer to like elements throughout unless otherwise noted. The present disclosure provides both a method and apparatus for fabricating a spacer frame for use in making a window or door. More specifically, the drawing Figures and specification disclose a method and apparatus for producing elongated spacer frames used in making insulating glass units. The method and apparatus are embodied in a production line that forms material into spacer frames for completing the construction of insulating glass units. While an exemplary system fabricates metal frames, the disclosure can be used with plastic frame material extruded into elongated sections having corner notches. 
       IGUs 
       [0042]    An insulating glass unit (IGU)  10  is illustrated in  FIG. 1 . The IGU  10  includes a spacer assembly  12  sandwiched between glass sheets, or lites,  14  ( FIG. 2 ). The assembly  12  comprises a as frame structure  16  and sealant material  18  for hermetically joining the frame to the lites to form a closed space  20  within the unit  10 . The unit  10  is illustrated in  FIG. 1  as in condition for final assembly into a window or door frame, not illustrated, for ultimate installation in a building. The unit  10  illustrated in  FIG. 1  includes muntin bars that provide the appearance of individual window panes. 
         [0043]    The assembly  12  maintains the lites  14  spaced apart from each other to produce a hermetic insulating space  20  between them. The frame  16  and the sealant body  18  co-act to provide a structure which maintains the lites  14  properly assembled with the space  20  sealed from atmospheric moisture over long time periods during which the unit  10  is subjected to frequent significant thermal stresses. A desiccant  22  removes water vapor from air, or other volatiles, entrapped in the space  20  during construction of the unit  10 . 
         [0044]    The sealant  18  both structurally adheres the lites  14  to the spacer assembly  12  and hermetically closes the space  20  against infiltration of airborne water vapor from the atmosphere surrounding the unit  10 . One suitable sealant  18  is formed from a “hot melt” material which is attached to the frame  16  sides and outer periphery to form a U-shaped cross section. 
         [0045]    The frame  16  extends about the unit&#39;s periphery to provide a structurally strong, stable spacer  12  for maintaining the lites  14  aligned and spaced while minimizing heat conduction between the lites via the frame. The preferred frame  16  comprises a plurality of spacer frame segments, or members,  30   a - d  connected to form a planar, polygonal frame shape, element juncture forming frame corner structures  32   a - d  and connecting structure  34  ( FIG. 3 ) for joining opposite frame element ends to complete the closed frame shape. 
         [0046]    The preferred frame  16  is elongated and has a channel shaped cross section defining a peripheral wall  40  and first and second lateral walls  42 ,  44 . See  FIG. 2 . The peripheral wall  40  extends continuously about the unit  10  except where the connecting structure  34  joins the two frame member ends. The lateral walls  40 ,  42  extend inwardly from the peripheral wall  40  in a direction parallel to the planes of the lites  14  and the frame  16 . The illustrated frame  16  has stiffening flanges  46  formed along the inwardly projecting lateral wall edges. The lateral wails  42 ,  44  add rigidity to the frame member  30  so it resists flexure and bending in a direction transverse to its longitudinal extent. The flanges  46  stiffen the walls  42 ,  44  so they resist bending and flexure transverse to their longitudinal extents. 
         [0047]    The frame  16  is initially formed as a continuous straight channel constructed from a thin ribbon of material. As described more fully below, the corner structures  32   a - 32   d  we made to facilitate bending the frame channel to the final, polygonal frame configuration in the unit  10  while assuring an effective vapor seal at the flame corners. A sealant is applied and adhered to the channel before the corners are bent. The corner structures initially comprise notches  50  and weakened zones  52  formed in the walls  42 ,  44  a frame corner locations. See  FIG. 4 . The notches  50  extend into the walls  42 ,  44  from the respective lateral wall edges. The lateral wails  42 ,  44  extend continuously along the frame  16  from one end to the other. The wails  42 ,  44  are weakened at the corner locations because the notches reduce the amount of lateral wail material and eliminate to the stiffening flanges  46  and because the walls are stamped or coined to weaken them at the corners. 
         [0048]    At the same time the notches  50  are formed, the weakened zones  52  are formed. These weakened zones  52  are cut into the  5 trip, but not all the way through. The connecting structure  34  secures the opposite frame ends  62 ,  64  together when the frame  16  has been bent to its final configuration. The illustrated, connecting structure comprises a connecting tongue structure  66  continuous with and projecting from the frame structure end  62  and a tongue receiving structure  70  at the other frame end  64 . The preferred tongue and tongue receiving structures  66 ,  70  are constructed and sized relative to each other to form a telescopic joint. When assembled, the telescopic joint maintains the frame  16  in its final polygonal configuration prior to assembly of the unit  10 . 
       The Production Line  100   
       [0049]    As indicated previously the spacer assemblies  12  are elongated window components that may be fabricated by using the method and apparatus of the present invention. Elongated window components are formed at high rates of production. The operation by which elongated window components are fashioned is schematically illustrated in  FIG. 5  as a production line  100  through which a thin, relatively narrow ribbon of sheet metal stock is fed endwise from a coil into one end of the assembly line and substantially completed elongated window components emerge from the other end of the line  100 . 
         [0050]    The line  100  comprises a stock supply station  102 , a punching station  104 , a roil forming station  106 , a crimper station  108 , and a severing station  110  where partially formed spacer members are separated from the leading end of the stock. At a desiccant application station  112  desiccant is applied to an interior region of the spacer frame member. At an extrusion station  114  sealant is applied to the yet to be folded frame member. A scheduler/motion controller unit  120  interacts with the stations and loop feed sensors to govern the spacer stock size, spacer assembly size, the stock feeding speeds in the line, and other parameters involved in production. At an assembly station  116 , the glass lites are affixed to the frame and sent to an oven for curing. 
         [0051]    As described more fully in the Calcei et al. patent, elongated coils  130 - 139  ( FIG. 6 ) are supported to a carriage  140  for back and forth movement in the direction of the double ended arrow  142 . One of the multiple coils is moved by the controller  120  to an uncoiling position for delivering a selected strip of sheet stock material to the downstream stations depicted in  FIG. 5 . 
         [0052]    The scheduler/motion controller unit  120  interacts with the stations and loop feed sensors to govern the spacer stock size, spacer assembly sire, the stock feeding speeds in the line, and other parameters involved in production. A preferred controller unit  120  is commercially available from Delta Tau, 21314 Lessen St, Chatsworth, Calif. 91311 as part number UMAC. 
       The Punching Station  104   
       [0053]    The punching station  104  accepts the stock S from a properly positioned coil at the stock supply station and performs a series of stamping operations on the stock as the stock S passes through the punching station. The punching station  104  comprises a supporting framework  238  ( FIG. 11 ) fixed to the factory floor. A stock driving system  140  moves the stock through the station until the stock is grasped by a downstream drive system  145  ( FIG. 11 ) described in more detail in the Calcei et at. &#39;681 Patent. Stamping units  144 ,  146 ,  148 ,  150 ,  152 ,  154  spaced along the station  104  in the direction of stock movement perform individual stamping operations on the stock S. 
         [0054]    The illustrated stock driving system  140  includes a pair of rollers  156 ,  158  secured to the framework at an entrance to the punching station  104 . The rollers  156 ,  158  are selectively moveable between a disengaged position in which the drive rollers are spaced apart and an engaged position in which the drive rollers engage an end portion of the strip S at the entrance of the punching station  104 . The rollers  156 ,  158  selectively feed the sheet stock into the punching station  104 . 
         [0055]    In the illustrated embodiment, a drive roller  156  is selectively driven by a motor coupled to a drive shaft  162  that is controlled by the controller  120 . An idle roller  158  is pivotally connected to its support framework. In the illustrated embodiment, the roller  158  is an idler roller that presses the sheet stock S against the roller  156  when the drive roller  156  is in the engaged position. The motor is controlled to feed the sheet stock through the station  104 . In the illustrated embodiment, a sensor is positioned along the path of travel near the stamping station and creates an output for verifying that stock S is being fed. 
         [0056]    The controller moves the pair of rollers  156 ,  158  to the disengaged, spaced apart position and indexes or moves an appropriate or selected sheet stock coil from the plurality of coils  130 - 139 . At the uncoiling position, a feed mechanism positions the sheet stock end portion between the pair of rollers  156 ,  158 . The controller  120  moves the pair of rollers  156 ,  158  to the engagement position to engage the coil end portion, and rotates the drive roller to feed the sheet stock into the punching station. In one embodiment, the stock driving system  140  is also used to withdraw stock from the stamping station  104  when strip stock of a different thickness, width or material is to fabricated into spacer frames. 
         [0057]    In the disclosed system, a stock driving system  145  on an output side of the punching station  104  engages the stock provided by the stock driving system  140 . The stock driving system  140  then disengages. The subsequent downstream drive system  145  has rolls that define a nip for securely gripping the stock and pulling it through the station  104  past a number of stamping units  144 ,  146 ,  148 ,  148 ′,  150 ,  150 ′,  152 ,  154 . The downstream drive system includes an electric servomotor to start and stop with precision. Accordingly, stock passes through the station  104  at precisely controlled speeds and stops precisely at predetermined locations, all depending on signals from the controller  120 . 
         [0058]    Each stamping unit  144 ,  146 ,  148 ,  150 ,  152 ,  154  comprises a die assembly and a die actuator assembly, or ram assembly. Each die assembly comprises a die set having a lower die, or anvil, beneath the stock travel path and an upper die, or hammer, above the travel path. The stock passes between the dies as it moves through the station  104 . Each hammer is coupled to its respective ram assembly. Each ram assembly threes its associated dies together with the stock between them to perform a particular stamping operation on the stock. 
         [0059]    Each ram assembly is securely mounted atop the framework  238  and connected to a fluid supply source  542  ( FIG. 22 ) of high pressure operating air via suitable conduits. Each ram assembly is operated from the controller  120 , which outputs a control signal to a suitable or conventional ram controlling valve arrangement when the stock has been positioned appropriately for stamping. 
         [0060]    The stamping unit  152  punches the connector holes  82 ,  84  ( FIG. 3 ) in the stock at the leading and trailing end locations of each frame member  16 . When included, a passage  87  is also punched in the stock by the unit  152 . In the illustrated embodiment, the die set anvil for punching the holes  82 ,  84  defines a pair of cylindrical openings disposed on the stock centerline a precise distance apart along the stock path of travel. The corresponding hammer is formed in part by corresponding cylindrical punches, each aligned with a respective anvil opening and dimensioned to just lit within the aligned opening. The stamping unit ram is actuated to drive the punches downwardly through the stock and into their respective receiving openings. The stock is fed into the stamping unit  152  by the downstream driving system and stopped with predetermined stock locations precisely aligned with the stamping unit  152 . The punches are actuated by the ram so that the connector holes  82 ,  84  are punched on the stock midline, or longitudinal axis. When the punches are withdrawn, the stock feed resumes. 
         [0061]    The stamping unit  148  forms the frame corner structures  32   b - d  but not the corner structure  32   a  adjacent the frame tongue  66 . The stamping unit  148  includes a die assembly  280  ( FIG. 7 ) operated by a ram assembly. The die assembly  280  punches material from respective stock edges to form the corner notches  50 . The die assembly  280  also stamps the stock at the corner locations to define the weakened zones  52 , which facilitate the folding of the spacer frame member at the corner locations. The ram assembly preferably comprises a pair of air actuated drive cylinders  290 ,  292  connected to an upper die drive plate  400 . Each weakened zone  52  is illustrated as formed by a score line (more than one score line may be included) radiating from a corner bend line location on the stock toward the adjacent stock edge formed by the corner notch  50 . The score line is formed on the stock strip S by a sharp edged ridge  457  disposed on a scoring tool  458  ( FIG. 14, 14A ) when contact occurs on the strip S between the scoring tool  458  and a flat surface or flat anvil. A face  459  of the tool  458  that engages the strip stock has a wedge shaped lip or ridge  457  spaced from two triangular elevated lands  461 ,  463 . The elevated shaped lands  461 , 463  bias the weakening zones  52  inward along the lateral walls  42 ,  44  at the notches  50 . In the illustrated embodiment, the frame members  16  produced by the production line  100  have common side wall depths even though the frame width varies. 
         [0062]    The stamping unit  150  configures the leading and trailing ends  62 ,  64  of each spacer frame member. The unit  150  comprises a die assembly operated by a ram assembly. The die assembly is configured to punch out the profile of the frame member leading end  62  as well as the profile of the adjoining frame member trailing end  64  with a single stroke. The leading frame end  62  is formed by the tongue  66  and the associated corner structure  32   a.  A trailing frame end  64  associated with the preceding frame member is immediately adjacent the tongue  66  and remains connected to the tongue  66  when the stock passes from the unit  150 . The ram assembly comprises a pair of rams each connected to a hammer. 
         [0063]    The corner structure  32   a  is generally similar to the corner structures  32   b - d  except the notches  50  associated with the corner  32   a  differ due to their juncture with the tongue  66 . The die assembly therefore comprises a score line forming a ridge like the die set forming the remaining frame corners  32   b - d.    
         [0064]    The stamping unit  146  forms muntin bar clip mounting notches in the stock. The muntin bar mounting structures include small rectangular notches. The unit  146  comprises a ram assembly coupled to the notching die assembly. An anvil and hammer of the notching die assembly are configured to punch a pair of small square corner notches on each edge of the stock. Accordingly the ram assembly comprises a single ram which is sufficient to power this stamping operation. A single stroke of the ram actuates the die set to form the opposed notches simultaneously and in alignment with each other along the opposite stock edges. 
         [0065]    Each time a new strip passes through the stamping station  104 , a scrap piece of stock is formed that is followed by a connected first spacer frame defining length of stock in a given series of multiple spacer frames. In one embodiment, the scrap piece is defined by the punching station  104  whenever a different coil is indexed to the uncoiling station and fed into the punching station  104 . The stamping unit  144  configures a leading edge of the scrap piece and trailing end  64  of the last spacer frame member in a series of spacer frame members formed from a particular coil from which the strip unwinds. The trailing edge of the scrap unit is formed by the stamping unit  150  when the leading edge of the first spacer in the next series of spacers formed from this particular sheet stock coil is stamped. The unit  144  comprises a die assembly operated by a ram assembly. The die assembly is configured to punch out the profile of the scrap piece leading end as well as the profile of the end  64  of the last frame member in the series of spacer frame members with a single stroke. The ram assembly comprises a pair of rams each connected to a hammer. 
         [0066]    At the end of a series of spacer frame members, the stamping unit  144  forms the trailing end of the last spacer frame member in the series and the leading end of the scrap piece. The stock is then indexed to a stamping unit  154  where the connection between the end of the last spacer frame member and the leading end of the scrap piece is severed. The unit  154  comprises a die assembly operated by a ram assembly. The die assembly punches the material that spans the respective stock edges to sever the stock. The runt assembly preferably comprises a ram connected to the upper die. 
         [0067]    A sensor detects the end of the last spacer frame in a series of spacer frame members. Upon detection of the severed end of the last spacer frame, the controller  120  causes the stock feed mechanism  140  to move the roller  156 ,  158  to the engaged position. The controller then actuates the motor to cause the drive roller to pull or retract the stock S out of the stamping station  104  and position the stock end at the entrance to the punching station. The stock that forms the last spacer frame member in the series is driven out of the machine by the downstream stock driving mechanism. The controller then moves the stock feed mechanism  140  to the disengaged position to release the stock end. The stock end remains secured by a clamping mechanism (not shown). The controller  120  may then index the next selected coil to the uncoiling position and place the end of this next selected strip between the rollers  156 ,  158 . The controller  120  then controls the stock feed mechanism to start the next series of spacer frame units. 
         [0068]    In order to accommodate wider or narrower stock passing through the station  104 , the die assembly is split into two parts. In one embodiment, one side of each die assembly is fixed and the opposite side of each split die assembly is adjustably movable toward and away from the corresponding fixed die assembly to allow different width spacer frames to be punched. Also each anvil is split into two parts and each hammer is likewise split. 
         [0069]      FIGS. 11 and 19  illustrate an example embodiment having a fixed side array of dies wherein an opposite side of the strip S path of travel includes moveable die sets. The moveable opposed hammer and anvil parts are linked by vertically extending guide rods  302 . The guide rods  302  are fixed in the hammer parts and slidably extend through bushings in the opposed anvil parts. The guide rods  302  both guide the hammers into engagement with their respective anvils and link the hammers and respective anvils so that all the hammers and anvils are adjusted laterally together. 
         [0070]    Referring to  FIG. 19 , the moveable hammer and anvil parts of each die assembly that make up the punching station  104  are movable horizonally towards and away (see Arrows X in  FIG. 19 ) from the fixed hammer and anvil parts by an actuating system  304  to desired adjusted positions for working on stock of different widths. The system  304  firmly fixes the die assembly parts at their horizonally adjusted locations for further frame production. The anvil parts of each die assembly are respectively supported in ways or guides attached to driving members  319 ,  320 ,  321 ,  322 ,  323 ,  325  attached to a stamping unit frame  238 . The hammer parts of each die assembly am also each supported in ways or guides, which are coupled to a respective die actuator, or ram. The guides extend transversely to the travel path P of the stock strip S and the actuating system  304  shifts the hammer parts and the anvil parts simultaneously along the respective ways between adjusted positions. 
         [0071]    The illustrated actuating system is controlled by the controller  120  to automatically adjust the punching station  104  for the stock width provided at the entrance of the station. The width of the stock provided to the station  104  may he detected and the controller automatically adjusts the station  104  to accommodate the detected width. The illustrated actuating system  304  provides positive and accurate moveable die assembly section placement relative to the stock path of travel. The system  304  comprises a plurality of drivescrews  316 , a drive transmission  318  coupled to the drivescrews, and die assembly driving members  319 ,  320 ,  321 ,  322 ,  323 ,  325  driven by the drivescrews  316  and rigidly linking the drivescrews to the anvil parts. The drive transmission  318  is attached to a die spacer  465  (described below) which rigidly attaches to an anvil support. 
         [0072]    The drivescrews  316  are disposed on parallel axes and mounted in bearing assemblies connected to lateral side frame members. Each drivescrew is threaded into its respective die assembly driving member  319 ,  320 ,  321 ,  322 ,  323 ,  325 . Thus when the drivescrews rotate in one direction the driving members  319 ,  320 ,  321 ,  322 ,  323 ,  325  force their associated die sections (hammer and anvil) to shift horizonally away from the fixed die sections. Drivescrew rotation in the other direction shifts the die sections toward the fixed die sections. The threads on the drivescrews  316  are precisely cut so that the extent of lateral die section movement is precisely related to the angular displacement of the drivescrews creating the movement. 
         [0073]    The hammer sections of the die assemblies are adjustably moved by the anvil sections. The guide rods  302  extending between confronting anvil and hammer die sections are structurally strong and stiff and serve to shift the hammer sections of the die assemblies horizonally with the anvil sections. The hammer sections are relatively easily moved along the upper platen guides or ways. 
         [0074]    Once the strip S leaves the punching station  104 , it enters a roll forming station  106  wherein a series of rolls contact the strip and bend it into a IS-shaped channel or form  312  shown in  FIG. 21 . Roll formers for accepting elongated strip and converning them into channel shaped elongated metal U shaped channels are know in the art and one example of such a roll former is commercially available from GED integrated Solutions Inc., assignee of the present disclosure. 
       Controlled Corner Formation 
       [0075]    As mentioned previously the ram assembly that forms part of the stamping unit  148  preferably comprises a pair of rams supported by the framework most preferably implemented using two air actuated drive cylinders  290 ,  292  commercially available from Festo Corp, under the designation or model number 13049375 or 13005438. An upper die assembly includes a drive plate  400  for at least two dies which move up and down (+/−⅜″) as along the y axis seen in the elevation view of  FIG. 7 . Downward movement of the drive plate  400  attached to the two dies is limited by one or snore rant limiting stops  410  having a contact region or surface  412  whose position with respect to a die support is adjusted depending on the material of the strip S passing through the station  104 . 
         [0076]    In an exemplary embodiment, the stamping unit has a first moveable die support  420  that supports one die for deforming one side of the strip S and as second moveable die support  422  that supports a second die for deforming an opposite side of the strip. These two die supports are coupled to the drive plate  400  for up and down movement with the drive plate in response to controlled actuation of the two air actuated drives  290 ,  292 . In the embodiment of  FIGS. 7 and 15 , both dies can be shifted (+/− approximately ¾ inch in the X direction, see  FIG. 7 ) to the side to accommodate different width strips S. When the two air actuated drive cylinders extend their pistons, the plate  400  is driven downward (−y) along with the attached die supports  420 ,  422  and brings the first and second dies into engagement with the strip. As seen most clearly in  FIG. 7 , bottom surfaces  424 ,  426  of the die supports engage the contact surfaces  412  of the stops  410  as a means of limiting movement of the dies and hence controlling the deformation of the strip S by those dies. 
         [0077]    The stamping unit  148  has first and second moveable anvil supports  430 ,  432  each supporting a stripping element  440  that the die passes through to come in contact the strip S and a die contact or backing element  442 . A region between the stripping element and the die contact element  442  defines a slot  444  which accommodates movement of the strip S through the punching station  104 . Guide rollers (not shown) route the strip stock S (along the z direction) into the region of the die with great accuracy (within 5 thousands of an inch) so that the strip just passes through the slot  440  without binding. The die contact element  442  has a flat upwardly facing surface  442   a  to which the die and particular the die ridge  459  ( FIG. 14A ) engages to deform the metal strip S when the metal strip is impacted by downward movement of the die. 
         [0078]    A representative die  450  is removably connect to respective die holders  451 ,  453  and is depicted in  FIGS. 13, 13A, 14, and 14A . The die  450  includes a notching portion  452  for removing metal from the strip S and a deforming portion  454  for deforming a portion of the metal of the strip near the removed metal to facilitate formation of a corner. 
         [0079]    In the illustrated example embodiment of  FIG. 7 , there are stops  410  on opposite sides of the strip S path of travel having upper facing, generally planar stop surfaces  412  which are contacted by the bottom surfaces  424 ,  426  of the die supports  420 ,  422  to limit transfer of energy from the dies to the strip and thereby control deformation of the strip. 
       Die/Anvil Positioning 
       [0080]    As mentioned above, the first and second anvil supports  430 ,  432  are coupled to their respective die supports  420 ,  422  by connecting guides  302 . This arrangement is further depicted in  FIG. 27 . The connecting guide  302  is securely attached to an associated die support and extends through bushings  303  (need to add to drawings) supported by the anvil support. This construction allows up and down movement of the die supports with respect to their associated anvil supports. These guides support and define the movement of the ram assembly with respect to the strip stock and are located in prescribed positions reducing friction and misalignment. Additionally as the anvil support is being translated back and forth to accept different width strip stock the guide  302  transmits a force to move the die support  420  relative the drive plate  400  in unison with die anvil support. 
         [0081]    Unlike the example embodiment of  FIG. 11 , wherein only one set of anvil and dies are moved by control of the controller  120 , the embodiment shown in  FIG. 15  is adjusted by manual rotation of a drive screw  470  that is rotated by a hand crank  471  in one sense or the other to either widen or narrow the gap between the dies and respective anvils. The exemplary drive screw  470  is an acme screw having two halves  470   a,    470   b  of different thread direction connected together by a coupling  472 . Each half of the drive screw engages a corresponding drive nut so that for example the drive screw half  470   a  engages a drive nut  473   a  and the drive screw half  470   b  engages a drive to nut  473   b.  In another embodiment not shown, the hand crank is replaced by a motor. 
         [0082]    Two movable mounts  474 ,  475  are attached to the drive nuts  473   a,    473   b  so that as rotation of the screw halves moves the drive nuts, the mounts  474 ,  475  move as well. Due to the reverse threads used in he screw halves the mounts  474 ,  475  move in opposite directions along the x axis as that axis is defined in  FIG. 15 . As the mount  474  moves in the positive x direction for example, is the mount  475  moves in the negative x direction. 
         [0083]    Threaded connectors  476 ,  477  attach removable stops  478 ,  479  to the mounts  474 ,  475  so that the stops move back and forth with the mounts as the screw halves are rotated. As seen also in  FIG. 15 , an adjustable spacer  465  is trapped or wedged between the removable stops  478 ,  479  and the anvil supports  430 ,  432 . These spacers  465  have two surfaces  480 ,  481  ( FIG. 26 ) trapped between generally planar surface of a removable stop and an anvil support. 
         [0084]    As seen in  FIG. 15 , a first pair of die and anvil assemblies are moveably supported by an elongated support  494  which extends to an opposite side of the strip stock path of travel where a second pair of die and anvil assemblies are moveably coupled to said elongated support.  FIG. 29  illustrations stationary guides or ways  309 ,  311 ,  313 ,  315  that guide the die support  420  and the anvil support  430  for back and forth movement in response to user adjustment of the crank. As seen in the figure, the anvil support  430  has two elongated flanges  431 , 433  that extend into the ways  309 ,  315  and slide back and forth in those ways. 
         [0085]    As seen most clearly in  FIGS. 24-26  the adjustable spacer  465  comprises a metal body  482  (preferrably hardened tool steel) having first and second outer cylindrical surfaces  483 ,  484  separated by a stepped region. A metal (preferably hardened tool steel) annular sleeve  485  has an inner diameter  486  that fits over a small diameter cylindrical surface  484  of the body  482 , and one or more annular spacers or shims  487  that define a spacing between one end  480  of the sleeve and an abutment  489  at the stepped region of the body  482 . 
         [0086]    The spacers or shims are made of stainless steel and can he chosen from a kit of such spacers having different thicknesses of, for example, 0.002 inch, 0.005 inch, 0.010 inch, 0.020 inch, 0.025 inch and 0.030 inch. By adding shims together, a length of the adjustable spacer between the two surfaces  480 ,  481  can be chosen to be between 1.300 to 1.600 inches. 
         [0087]    The body  482  has a throughbore  491  to accommodate an elongated threaded connector  490  having a hex head ( FIG. 15 ). The hex head connector  490  butts against a washer that engages the respective removable stops  478 ,  479  and the connector extends through the stop, the bore  491  of the adjustable spacer  465  and threadingly engages a corresponding threaded opening in the anvil support  430 . 
         [0088]    The removable stops  478 ,  479  and can be removed from the mount  474 ,  475 . As discussed below, the ram stops  410  are generally cylindrical and have threaded bases that screw into openings in the anvil supports  430 ,  432 . By removing the removable stop  478  and spacer  465  on one or both sides of the strip stock travel path, the anvil support  430  and corresponding die support  420  can be removed as a unit by sliding them through the fixed ways. The plate  494  extends the length of the punching station  104  and supports ways or guides for other die supports that form part of the punching station  104 . An output end of the screw  470  supports a pulley wheel  496  that engages an aligned pulley wheel (not shown) by means of a pulley to transmit the rotation applied by the user to a separate drive for moving other die sets that form muntin bar notches and a leading frame end  62 . 
         [0089]    Exemplary ram limiting stops  410  have a fixed cylindrical portion or base  500  made of hardened tool steel attached to the anvil support  430  by means of a threaded part  415  of the base and a threaded opening in the anvil support. A thickness T of the removable top portion  510  is used to control a total length of the stop  410 , and therefore, the extent of die movement and consequently deformation of the strip S. In the exemplary embodiment, the thickness of the removable cylindrical portion  510  varies over a range to adjust downward movement of the die by as much as 0.010 inch. (ten thousandths of an inch) Stated another way, the a stainless strip S a thickness of the removable portion  510  provides adequate deformation with a stop thickness T and for Tin Plate strip of the same thickness, a removable stop is chosen having a thickness T+0.004 inch to reduce the energy transmitted to Tin plate strip. 
         [0090]    The exemplary removable portion  510  of the stop  410  is also made of hardened tool steel and a centrally located recess  512  which fits over a stud  514  in the fixed portion  500  of the stop. Two magnets  520 ,  522  that attract the steel top  510  fit into recesses  524 ,  526  of the fixed portion  500  of the stop and have top surfaces flush with a top surface  530  of the fixed stop portion  500 . 
         [0091]    An alternate implementation of a ram stop is depicted in  FIG. 9 . This figure depicts a stop assembly including a moveable stop on each side of the strip and wherein the moveable stop has a stepped surface generally parallel to a plane of the strip which defines first and second limits of to travel of the ram assembly. The stop assembly includes an actuator  830  which operates wider the direction of the control station  120  to move a shaft  836  which in turn selectively moves first or second regions  832 ,  834  of the stepped surface of the stop along a path dictated by a guide  842  supported by a base  840  of the moveable stop into a portion for contact by the lower surface of the die support. 
         [0092]    In the exemplary embodiment the punch drives for moving the plate  400  are air actuated drives. In an alternate embodiment, rather than precisely controlling a degree of length of travel the dies move in response to actuation of the air acutated drives, in accordance with an alternate embodiment, the pressure supplied to the air drive is adjusted by an output from the control station  120 . In yet another alternative example embodiment, the drive cylinders  290  and  292  are hydraulically actuated cylinders energized by a supply pump and motor. 
         [0093]    The exemplary system limits movement of the dies in a somewhat empirable fashion to achieve a best result of corner fabrication. The comet amount of energy is determined by the use of a fold force gage. A goal is to achieve the same fold force regardless of material, and make the adjustments to the stop height dimension to achieve that goal. 
         [0094]    Rather than a use of adjustable height stops, the drive cornea in contact, an alternate embodiment uses an eccentric drive having a cam follower so that the throw of the drive is readily adjustable. In this embodiment the die stops would not be used as previously described above. Rather the length of travel is controlled by the position of the crank arm on a crank hub. The crank arm converts rotary motion to a linear motion. If the position of the crank arm is further away from the center of rotation of the crankshaft then the length of travel will increase. If the crank arm position is closer to the center of rotation of the crankshaft then the length of travel will decrease. By controlling the crank arm position, the effective stroke and length of travel can be controlled. 
         [0095]    Another alternate embodiment has a die support  420  constructed from two wedge shaped mating pieces. One of the wedge shaped pieces is driven in and out horizonally with a servomotor. This horizonal motion would result in a net increase or decrease in length of travel when the die support  420  comes in contact with stops  412   
         [0096]    An alternate example embodiment of the punch station  104  is depicted in  FIG. 11 . This station has two dedicated stamping stations for forming the corners  32   a,    32   b,    32   c,    32   d.  Two stamping stations  148 ,  148 ′ are capable of stamping the three corners  32   b,    32   c,    32   d  that are separated from the tongue. And the two stamping stations  150 ,  150 ′ are capable of stamping the corner  32   a.  For one material, stainless steel for example, the stations  148 ,  150  are set up for forming the corners. If a demand for tin plated steel frames is subsequently being satisfied (by the control station  120  choosing an appropriate supply roll at the stock supply station  102  for feeding through the line) the control station forms the corners by selective actuation of a second set of stamping stations  148 ′,  150 ′ that deform the strip in a slightly different manner. Alternate different means of adjusting the deformation at the two stations  148 ,  148 ′ have been discussed above. 
         [0097]      FIG. 22  is a schematic depiction of a pneumatic system  540  for pressurizing the dual acting air cylinders  290 ,  292  at the punching station  104 . The two air cylinders  290 ,  292  are coupled to an air source  542  through a solenoid operated valve  544  that delivers air at 80 psi to the air cylinders having a piston of ⅝ inch diameter and a throw distance of ⅝ inch. The solenoid  544  responds to control outputs from the controller by switching back and forth from a position in which the plate  400  is raised and a position which forces the plate downwardly to notch the strip S. Other solenoid operated valves  546   a,    546   b,    546   c,    546   d  are also depicted in  FIG. 22 . The ports for the valve  544  are labeled in detail in  FIG. 22A  wherein port  1  has been labeled with reference character  548 , port  2  with reference character  549 , port  3  labeled with reference character  550 , port  4  with reference character  551  and port  4  with reference character  552 . 
         [0098]    Turning to  FIG. 23 , one secs the connections to the two air driven cylinders  290 ,  292  in more detail. A pair of T connectors route air passing through the solenoid valve  544  to the cylinders. A first T connector  554  is connected to port number  2  on the solenoid valve  544 . When pressurized air is provided by this port, the cylinders lift the plate  400  up against the action of gravity. When a second T connector  556  receives pressured air from port number  4  of the valve  544  the cylinders drive the plate  400  downwardly in a controlled manner. This arrangement allows one connector ( 554  for example) to pressurize one of the internal air cylinder chambers of both air cylinders  290 ,  292  while another chamber of the cylinder is vented or exhausted through the other connector ( 556  for example) then through the solenoid valve and then to atmosphere. 
         [0099]    In the exemplary embodiment, the two air cylinders  290 ,  292  are connected to an improved quick exhaust  560  ( FIG. 23 ) available from Festo as part number and SE-1/2- 3 . The quick exhaust  560  has a threaded exhaust port  561 . A flow control  562  is threaded into the exhaust port of the quick exhaust. The flow control has an integrated sintered silencer  563 . An exemplary flow control  562  is available from Festo as part number GRE-1/2. 
         [0100]    A goal of use of the flow control  562  is to not noticeably slow the speed of the dies but improve the consistency of the strikes by the die against the strip. Stated another way, the flow control  562  allows for as known or regulated control of the exhaust to allow for a substantially repeatable load force applied to the strip S by the dies and anvils of the punch station  104 . 
         [0101]    A study of the operation of the corner notching has led to a better understanding of how various factors affect corner fold quality. Generally, after a production line is converted from Tin Plate to Stainless Steel a range of fold force (forming the 90 degree angle between spacer frame segments  30  shown in  FIG. 1 ) readings vary by about 5 oz. That is, the force needed to bend the severed frame from its original elongated linear strip form to a closed form vary over a range of about 5 oz for both stainless steel and tin plated steel. It has been found that after an extended period of use the fold force experienced can often have a range of over 10 oz. This difference is attributed to changes in the system over time such as clogged flow paths in the pneumatic circuit coupled to the cylinders  290 ,  292  and to structural wear in the components forming the punch station  104 , such as the guide rods  302 . As the components wear, the system friction is reduced. This reduced friction results in inconsistent acceleration of the dies. 
         [0102]    The die stroke is about ⅗ inch. The travel time from an up limit switch signal to a down limit switch signal is about 7 milliseconds. These limit switches are attached to the air cylinder body and detect when an inner piston is up (retracted) or/down (extended) position. During this 7 millesec time the acceleration and final velocity of the dies (in the downward punch direction) is affected by several factors. Gravity is accelerating the dies. Friction is resisting the acceleration. Air pressure coming into the cylinders is accelerating the load. Air pressure on the exhaust side of the cylinder is resisting acceleration. The shearing force required to notch the strip is trying to stop the load. 
         [0103]    Gravity is a constant, its force will not change over time. Friction should be fairly consistent over a relatively short time period. However, friction will change over time as wear takes place. Friction may also be sharply increased or decreased with press alignment and die binding. Adjustments to the press can be made which inadvertently apply a mechanical bind to the system. Air flow in and out of the cylinders will also be fairly consistent over a short time period. Air flow characteristics however can change dramatically over time. This change is expensed as mufflers in or silencers become plugged, air flow is restricted. 
         [0104]    When the air supply to the punch station  104  is removed, the dies will fall due to gravity. If the air supply is toggled on and of several times and one observes how the dies fall, one will see some variation in the manner in which the dies fall. Sometimes the die will fall quickly, and sometimes they may fall slower, in Some cases they may only fall part way, pause and then fall the rest of the way. Using pneumatics to consistently accelerate a load that will freefall, leads to some small variations. Since air is a compressible fluid, small changes in external conditions such as mechanical binding or air flow restrictions can result in noticeable changes in the consistent delivery of energy to the punch driver system. Adding the flow control  562  after the quick exhaust achieves much greater consistency in both time and load applied to the strip S by the dies. 
         [0105]    Set up of the flow control is to some degree empircle but can be simplified if the actual force of engagement between the die and the strip S is measured. This can be performed using a force gauge commercially available from GED Integrated Solutions Inc., assignee of the present invention, (part number 2-24472) The Exemplary flow control  562  has an adjustment feature. By turning a screw. The flow control has a tapered cone spaced from a mechanical seat. The closer the cone is to the seat, the more restricted is the airflow, on the control, the flow path through the control can be adjusted for maximum flow. Best results are obtained if the flow is somewhat restricted however, so that in one exemplary system best results were obtained by rotating the screw three turns, resulting in approximately 30% reduction in flow. The exemplary flow controls have about 10 full turns (360 degrees) from open to closed, so 3 turns from open would be about 30% restriction. The data in Table 1 below was obtained at this setting and measures the actual measured force applied to a gauge in ounces for twelve readings. Note the range from the maximum to the minimum is only 5 ounces compared to values measured of as much as 12 ounces for a non flow restricted exhaust. This data is obtained by using the 2-24472 fold force gauge. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Flow restricted 
               
             
          
           
               
                 Corner 1 
                 Corner 2 
                 Corner 3 
                   
                   
               
               
                   
               
             
          
           
               
                 48 
                 53 
                 48 
                 Minimum 
                 48 
               
               
                 48 
                 51 
                 48 
                 Maximum 
                 53 
               
               
                 49 
                 50 
                 48 
                 Range 
                 5 
               
               
                 48 
                 51 
                 49 
                 Average 
                 49 
               
               
                   
               
             
          
         
       
     
       Crimper Station  108   
       [0106]    A crimper assembly  610  ( FIGS. 16, 17, 18 and 19 ) is connected to an output end of the roll former station  106  and processes roll formed strip  312  output from the roll former  210 . The simper assembly has two movable carriages  614 ,  616  that are coupled to linear bearings  620 ,  622  which move along spaced apart generally parallel tracks or guides  624 ,  626  that extend along the exit side of the roll former. 
         [0107]    The carriages  614 ,  616  are connected by first and second horizonally extending rods  630 ,  632  that pass through openings in the carriages  614 ,  616 . The rods are anchored to one carriage  616  and on an opposite side of the path of travel the rods pass through bearings  640 ,  642  supported by the carriage  614 . This arrangement allows the spacer frame width created by the rollformer to be varied with only minor adjustments to the crimper assembly  610 . 
         [0108]    A first steel roller  644  mounted on the lower rod  632  supports the spacer frame  312  as it exits the roll former. Springs (not shown) engage ends of this roller and are compressed between two side plates  650 ,  652  and the roller. This arrangement keeps the roller centered regardless of the spacer size being formed. The height of the crimper assembly  610  in relation to the roll former is adjusted  30  that the lower roller  644  just touches the bottom of the spacer frame as the spacer frame exits the roll former. 
         [0109]    Pivotally mounted on the upper rod  630  is a yoke  654  which supports an upper roller  656 . The yoke pivots on the upper rod. The upper roller is directly above the lower roller. An air cylinder  600  is mounted to the yoke  654 . The amount of force the cylinder  660  applies to the upper roller is controlled by a precision regulator. If the cylinder does not apply enough pressure on the roller, the roller will not engage the spacer frame corners. If the upper roller  656  does not have enough down force, the cross-travel of the crimper carriage will force the upper roller out of the groove of the spacer and hit late or not at all firmly enough and the crimp will be late or nonexistent. If the cylinder force is too high, the roller will lock into the front of the lead and the crimp will not be in the desired location. 
         [0110]    The exemplary crimper assembly  610  also includes two horizonally oriented pneumatically actuated cylinders  670 ,  672 . Crimping lingers  674 ,  676  are attached to the output drive rods  378  of these cylinders. The crimping fingers  674 ,  676  are located so that their center line of action extends parallel to and intersections a region between the center lines of rotation of the rollers  644 ,  656 . When the cylinders are extended the crimp fingers strike the corners or leads at their center. 
         [0111]      FIG. 20  is a perspective view of either of the crimping fingers  674 ,  676 . A threaded opening in a mourning block  677  allows the fingers  674 ,  676  to attached to the output of the respective drive cylinder  670 ,  672 . In one example embodiment, the crimping fingers  674 ,  676  are made from a tool steel or flame hardened steel as would be appreciated by one of ordinary skill in the art. 
         [0112]    A v-shaped contact  681  has a beveled underside  683  which extends from a concave shaped portion  679  of the fingers  674 ,  676 . A top portion of the contact  681  comes into contact with the lateral walls  42 ,  44  of the frame structure  16  (see  FIG. 1 ) initially and continued movement of the fingers bring the beveled underside  683  into engagement with the frame to crease the frame in the region of weakness  52  at the notch  50 . 
         [0113]    The contact  681  further comprises an apex  685  extending to the contact&#39;s most distal point. The concave portion  679  includes two faces  701 ,  703 , tranversely located with the concave portion and spaced apart by the contact  681 . The faces  701 ,  703  terminate at a proximal end of the contact  681 . A cylindrical boss  707  extends from each of the faces  701  and  703  beyond the apex  685  of the contact  681 . The cylindrical bosses  707  are received and supported by a cylindrical support opening  709  located in respective faces  701 ,  703  and extend beneath the concave portion  679  of the fingers  674 ,  676 . 
         [0114]    Securing the bosses  707  into the respective support openings  709  are respective fasteners  711 . In one example embodiment, the fasteners  711  are socket head set screws. In another example embodiment, the cylindrical bosses  707  are supports sold by GED Integrated Solutions under part number 758-0220. 
         [0115]    During operation, an apex  685  of the fingers  674 ,  676  centrally engages (along the z axis of  FIG. 21 ) the area of weakness  52  by the apex  685 , which continues to a prescribed first depth along the x axis of both lateral walls  42 ,  44  of the frame  16 . Once the first prescribed depth is reached, the cylindrical bosses  707  contact symmetrically at first and second points  713 ,  715  about the area of weakness the lateral walls  42 ,  44 . This removes contact between the lateral walls and apex  685 , while continuing the deformation of the respective lateral wall near the region of weakness  52  along the x axis to a second depth. Both the first and second prescribed depths occur in a single advancement of both fingers  674 ,  676  during a single cycle. In one example embodiment, the Is difference between the first prescribed depth and the second prescribed depth is 0.030 inches. 
         [0116]    The apex  685  and bosses  707  bias the frame members into the channel bounded by the side walls of the frame and provide a controlled bending operation to form the spacer frame segments  30  (see  FIG. 1 ) when the frames are bent ninety (90) degrees. This controlled bending operation allows for the lateral walls  42 ,  44  in the region of the notches daring and upon completion of bending to remain substantially planer with the surfaces of the frames away from the notched  50  regions. 
         [0117]    An extension spring  680  attached to the carriage  616  ties one side of the crimp assembly to a fixture  681  on a lower rollformer. This spring returns the crimp assembly  610  to a start position S (See  FIG. 12A ) after a crimp operation. Two small shock absorbers  682  prevent bounce when the Crimp Assembly stops. 
         [0118]    A pneumatic system for the crimper has four exhausts located at the ports of the crimping cylinders  670 ,  672 . They help to achieve maximum speed from the cylinders. There are two solenoid valves. One raises and lowers the top roller. The other activates the Crimping fingers. There are two pressure regulators. A first regulator determines how hard the crimp cylinders pushes on the spacer. If this regulator is set too high it will break through the corners. If it is too low the corners will not be struck hard enough. 60 to 80 psi is the exemplary range for this regulator. 
         [0119]    The second regulator is a precision regulator that determines how much pressure is applied to the top roller  656  by the cylinder  360 . It is set properly when the roller locks into the corners and leads and the crimp is in the correct location. It is preferable when adjusting this regulator to start from the low end and increase the pressure until the desired results occur. If the crimper engages too early on the leads, the pressure is too high. If the crimps are late, the pressure is too low. 
         [0120]      FIG. 18  illustrates a line of force  680  that is applied to a point on the yoke wherein a output from the cylinder  660  is pinned to the yoke  654 . A force against this point exerts a moment about the pivot point of the yoke defined by the axis of rotation of the rod  630  which in tom results in a controlled downward force of engagement between the top roller  656  and the spacer frame  312 . By controlling the pressure applied to the cylinder this force of engagement can be adjusted to achieve proper crimping action. 
       Sensor Components 
       [0121]    When an ON/OFF switch (not shown) is set to the ON position power is supplied to the crimper assembly. After power is turned on the crimper fingers are disabled until there is material threaded through the roll former. A photoeye located near spacer frame  312  enables the crimper assembly once Material is present. If no Material is present the crimper fingers will not operate. 
         [0122]    At the bottom of the crimper assembly on one side there are two proximity sensor switches. They are named MIN and MAX. The MIN switch  690  is the switch that is covered by a bottom surface of the side plate  314  when the Crimper Assembly is not engaged with the spacer frame. The MAX proximity switch  692  is near the end of the travel when the Crimper Assembly is engaged with the spacer frame. Relays (not shown) which are actuated under the control of the controller  122  are used to control the actions of the crimper fingers. 
       Operation 
       [0123]    When the top roller engages into a corner or lead the movement of the spacer frame drags the Crimper Assembly off of the MIN proximity switch. When the MIN switch is lost it causes the Crimper fingers to extend. When the Crimper Assembly triggers the MAX limit switch the Roller and Crimper fingers retract so that they are no longer touching the spacer. Once they are retracted the Crimper Assembly returns to the MIN switch position. During operation of the fingers, a crimp pressure is initially set to be at least 60 psi and a maximum pressure is set to 85 psi. A roller down pressure is set to a minimum starting pressure of 0.10 Mpa and a maximum pressure of 0.25 Mpa. 
         [0124]    While an exemplary embodiment of the invention has been described with particularity, it is the intent that the invention include all modifications from the exemplary embodiment falling within the spirit or scope of the appended claims.