Abstract:
A cutoff unit for cutting a variably swept continuous beam extending from a roll forming mill includes a pickup subassembly for tracking a shape of the continuous beam, and a cutoff subassembly that engages and supports sides of the continuous beam while a blade slices transversely through the continuous beam. A controller connected to the roll forming mill and to the cutoff unit controls the cutoff unit to allow pass through of the continuous beam, and is configured to actuate the pickup and then actuate the blade to cut the continuous beam into longitudinally symmetrical beam segments, each having a center section (swept or not) and with mirror-image equally-swept end sections.

Description:
This application claims benefit under 35 U.S.C. §119(e) of provisional application Ser. No. 60/980,554, filed Oct. 17, 2007, entitled VARIABLE ADJUSTABLE CUTOFF DEVICE FOR ROLL FORMERS, the entire contents of which are incorporated herein. 
    
    
     BACKGROUND 
     The present invention relates to cutoff devices for cutting a roll formed continuous beam having a multi-curved longitudinal shape as it exits a roll former mill. 
     A known prior art cutoff device (see Heinz U.S. Pat. No. 5,305,635) is able to cut a (single radius) swept tubular continuous beam into beam segments. The beam segments each have a predetermined length and shape making them useful as bumper reinforcement beams. Recently, Shape Corporation employees have conceived of an apparatus and method involving a sweep station at the end of a roll former that allows a continuous beam to be given multiple/different sweeps. Beam segments can be cut from the continuous beam that have increasingly curved ends, thus providing beam segments matching the designed vehicle shape without the need for secondary processing to reform ends of the beam segment. This saves considerably by reducing secondary processing of the beam segments. A problem is that a continuous beam with multiple/different sweeps tends to oscillate up and down quite dramatically as a first curved shape first exits the sweep station and then as a second more-curved (or less curved) shape exits the sweep station, especially when the roll former is operated at significant line speeds. The cutoff device in Heinz &#39;635 is not able to handle this oscillating movement when the movement is rapid and substantial. 
     SUMMARY OF THE PRESENT INVENTION 
     In one aspect of the present invention, an apparatus includes a roll former for roll forming a sheet of material into a continuous beam, and a rapidly-adjustable power sweep unit in-line with the roll former for sweeping the continuous beam into a curvilinear shape having longitudinal sections with at least two different sweeps at selected locations. A cutoff unit is provided in-line with the sweep unit for cutting the continuous beam, the cutoff unit including an extendable pin for engaging the continuous beam to temporarily move the cutoff unit along with the continuous beam and including a guillotine-type cutting blade for cutting a beam segment of predetermined length from the continuous beam. A controller is operably connected to the roll former, the sweep unit, and the cutoff unit for controlling coordinated cyclical adjustment of the sweep unit and coordinated actuation of the cutoff unit, whereby the beam segments have a desired length and have the at least two different sweeps at desired locations along the desired length. 
     In another aspect of the present invention, a cutoff unit is provided for receiving a continuous beam from a roll former apparatus, where a length of the continuous beam has different longitudinal sweeps. The cutoff unit includes a pickup device that rollingly engages and tracks with the continuous beam as the continuous beam exits the roll former apparatus. The pickup device includes an extendable pickup member for engaging the beam to cause the pickup device to temporarily move with the continuous beam and includes a shock absorber to reduce impact when the pickup member engages the continuous beam and first begins to move therewith. A cutter device is attached to the pickup device for cutting the continuous beam, and a controller is operably connected to the pickup device and to the cutter device to actuate the extendable pickup member to engage the continuous beam and then actuate the cutter device to cut a beam segment of predetermined length from the continuous beam. 
     In a narrower aspect, the beam is tubular (for example, “D” or “B” shaped beams), and the pickup device and the cutter device are adapted to receive the beam as a position of the beam changes dramatically as the beam exits a roll former due to the different longitudinal sweeps. 
     In another aspect of the present invention, a cutoff unit is provided for receiving a continuous beam from a roll former apparatus, where a length of the continuous beam has different longitudinal sweeps. The cutoff unit includes a pickup device adapted to engage the continuous beam as the continuous beam exits the roll former apparatus. A cutter device is pivoted to the pickup device at a pivot and also is attached thereto by an adjustable link for adjusting an orientation of the cutter device relative to the pickup device. 
     In still another aspect of the present invention, a method includes providing a roll former for roll forming a sheet of material into a continuous beam, and providing a rapidly-adjustable power sweep unit in-line with the roll former for sweeping the continuous beam into a curvilinear shape having longitudinal sections with at least two different sweeps at selected locations. Further, the method includes providing a cutoff unit in-line with the roll former for cutting the continuous beam. The cutoff unit includes an extendable pin for engaging the continuous beam to temporarily move the cutoff unit along with the continuous beam and includes a guillotine-type cutting blade for cutting a beam segment of predetermined length from the continuous beam; and controlling coordinated cyclical adjustment of sweep unit and coordinated actuation of the cutoff unit to cause the beam segments to have a desired length and to have the at least two different sweeps at desired locations along the desired length. 
     In a narrower form, the present invention includes connecting a controller to the roll former, the sweep unit, and the cutoff unit, and includes programming the controller for coordinating movement of same. 
     These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view of a roll forming apparatus including an in-line variable sweep station and an in-line cutoff unit connected to the sweep station embodying the present invention, the cutoff unit including a pickup assembly and a cutoff assembly. 
         FIG. 1A  is a top view of a bumper reinforcement beam segment cut from the continuous beam made via the apparatus of  FIG. 1 , and  FIG. 1B  is a cross section through  FIG. 1A . 
         FIG. 2  is a perspective view of the cutoff unit of  FIG. 1 , and  FIG. 3  is a perspective view similar to  FIG. 2  but with the overhead counterbalance unit and pull-back cylinders of the cutoff unit removed. 
         FIG. 4  is a perspective view of the cutoff unit and counterbalance unit of  FIG. 1 , and  FIGS. 5-6  are perspective views similar to  FIG. 4  but with the counterbalance unit removed and with the continuous beam removed. 
         FIG. 7  is a perspective view of the beam-engaging pickup carriage of the pickup assembly of  FIG. 6 . 
         FIGS. 8-9  are perspective views of the pickup pin and actuator and associated subframe of the pickup assembly of  FIG. 6 . 
         FIG. 10  is a perspective view of the cutoff assembly of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     It is contemplated that the present apparatus can be used in various orientations, and thus relational terms such as “upper,” “lower,” “top,” “bottom,” “sides,” “right,” “left,” “vertical,” “horizontal,” and the like are used only to facilitate description, and are not intended to be unnecessarily limiting. 
     The illustrated apparatus  50  ( FIG. 1 ) includes an uncoiler  51  for uncoiling a roll of steel sheet material  52 , a stamper  53  for forming holes at predetermined locations in the sheet material  52 , a roll former  54  with in-line automatically-variable sweep unit  55  for forming a multi-swept continuous beam  56 , and a cutoff unit  57  for cutting the continuous beam  56  into beam segments  58  with a centered large radius sweep S 1  and end sections with smaller radius sweeps S 2 . The apparatus  50  may include a welder near an end of the roll former  54  for welding the sheet  52  into a permanent tubular shape. It is noted that roll formers with in-line sweep units are known in the art, such that the present disclosure is sufficient for a person skilled in this art. However, for additional detail the reader is directed to co-assigned U.S. Pat. Nos. 5,092,512; 5,454,504; and 7,337,642, and also to co-assigned application Ser. No. 11/689,320, filed Mar. 21, 2007, all of which are incorporated herein by reference in their entirety. 
     The illustrated apparatus  50  can roll form and produce multi-swept beam segments  58  at high volumes and with high dimensional accuracy in near net final shapes that match a front (or rear) of a vehicle, but with relatively few secondary processes. During operation of the apparatus  50 , the continuous beam  56  is swept to include different curvatures (such as illustrated sweeps S 1  and S 2 ) such that it oscillates and “waves” dramatically up and down as the beam  56  exits the roll former  54 . This oscillating movement increases in speed and amplitude when the sweeps S 1  and S 2  are significantly different, and/or when a speed of the roll former  54  is increased, and/or when a length of the beam segment  58  is quite long (e.g., a bumper reinforcement beam which extends a width of a vehicle frame), and/or when the sweeps S 1  and S 2  are in opposite directions. The present cutoff unit  57  is adapted to accommodate the large oscillating movement and still cut the continuous beam  56  into beam segments  58  with accuracy in length and with accuracy in longitudinal positions of the sweeps S 1  and S 2 . For example, it is contemplated that a longitudinal position of the sweeps S 1  and S 2  can be made accurate to within less than about 1-2 mm, thus allowing the radii of sweeps S 1  and S 2  to be accurate to within about 2-3 mm even near ends of the sweeps S 1  and S 2  . . . while still allowing the beam segments  58  to be produced at 100 fps or more line speeds and while still meeting the very tight dimensional standards of automotive parts. Further, the present cutoff unit  57  is able to accommodate and accurately cut beam segments  58  with different sweeps, such that two different bumper reinforcement beam segments (each having an identical cross-sectional shape but different S 1  sweeps and different S 2  sweeps) can be made on the same roll former apparatus substantially without stopping the apparatus  50 . 
     The present cutoff unit  57  ( FIG. 3 ) includes a pickup device  60  (also called pickup assembly) and a downstream cutter device  61  (also called cutoff assembly) pivoted to the pickup device  60  at pivot  62  and also attached thereto by adjustable link  63  at the bottom to form a triangular supportive arrangement. This arrangement allows the orientation of the cutting blade  64  to be adjusted to a desired cutting angle and then fixed relative to a continuous beam  56  passing therethrough. The pickup device  60  includes an extendable pin  66  that is extendable to accurately engage a hole in the continuous beam  56 , so that the cutoff unit  57  travels temporarily along with the continuous beam  56  as the cutoff blade  64  is operated. 
     The center of gravity of the cutoff unit  57  (including devices  60  and  61 ) is basically at pivot  75 , which is spaced slightly below and away from the pivot  62 . It is noted that the relationship between pivot  75  and pivot  62  has no effect on the operation of the unit. A weight of the cutoff unit  57  is supported by an overhead counterbalance  65  ( FIG. 1 ). The rollers and bearings on the device  60 , assisted by the counterbalance  65 , cause the cutoff unit  57  to rotationally and translatingly track with the continuous beam  56  as the beam  56  exits/extends from the sweep unit  55  through the cutoff unit  57 . Also, the rollers and bearings assist in keeping the devices  60  and  61  in position (i.e., traveling with the continuous beam  56 ) during the step of actuating a cutoff blade  64  to separate a bumper beam segment  58  from the continuous beam  56 . Also, after the cut is made, the rollers allow the cutoff unit  57  to roll back along the continuous beam  56  in an upstream direction toward its home position adjacent the sweep unit  55 . 
     The several actuators associated with the cutoff unit  57  are all connected to a controller  59  ( FIG. 1 ) (which is also connected to the roll former  54  and the variable sweep unit  55 ) for coordinated operation so that when the beam segment  58  is cut off, it has equally-swept end sections with a sweep S 2  defining a smaller radius at each end, and has a swept (or linear) center section with a sweep S 1  defining a larger radius. 
     There is an actuator  150  in the cutoff system with a cylinder that changes the relationship, more or less vertically, of the cutter device  61  to the pickup device  60 . During the process of cutting the part this cylinder functions as follows: After the pickup pin  66  has been engaged and the beam  56  is in position longitudinally to be cut, cylinder  150  lowers the cutter device  61  down to a point where the upper cutting steels are in contact with the top of the beam  56 . At this point the wall-supporting member  68  is raised by cylinder  124 , cylinder  141  extends cutting the beam and then retracts. Cylinder  124  then retracts lowering the wall-supporting member  68 . Then cylinder  150  raises the cutter device  61  up to the home position allowing clearance for the beam and its multiple sweeps to pass through the cut off unit without contacting the cutting steels. 
     By using a programmed controller  59 , two different beam segments can be made, each having a same cross section (from the roll former  54 ) but with different S 1  sweeps and/or different S 2  sweeps and/or different lengths. Notably, by using the roll former and sweep apparatus shown in application Ser. No. 11/689,320, filed Mar. 21, 2007, a beam segment can be severed from the continuous beam, with opposing swept sections accurately located longitudinally therein. This accurate position of the sweeps is important since any error in location is compounded by dimensional out-of-tolerance conditions in both adjacent beam segments  58 . 
     As defined in the claims, the apparatus  50  includes a roll former  54  for roll forming a sheet of material  52  into a continuous beam  56 , and a rapidly-adjustable power sweep unit  55  in-line with the roll former  54  for sweeping the continuous beam  56  into a curvilinear shape having longitudinal sections with at least two different sweeps S 1  and S 2  at selected locations. A cutoff unit  57  is provided in-line with the roll former  54  for cutting the continuous beam  56 , the cutoff unit  57  including an extendable pickup member (i.e., pin  66  ( FIG. 9 )) for engaging the continuous beam  56  to temporarily move the cutoff unit  57  along with the continuous beam  56  and including a guillotine-type cutoff blade  64  for cutting a beam segment  58  of predetermined length from the continuous beam  56 . The pickup device  60  also includes a shock absorber  67  ( FIG. 7 ) to reduce impact when the pickup member  66  engages the continuous beam  56  and first begins to move therewith. A controller  59  ( FIG. 1 ) is operably connected to the roll former  54 , the sweep unit  55 , and the cutoff unit  57  for controlling coordinated cyclical adjustment of sweep unit  55  and coordinated actuation of the cutoff unit  57 , whereby the beam segments  58  have a desired length and have the at least two different sweeps S 1  and S 2  at desired locations along the desired length. 
     Notably, the beam can be tubular (for example, “D” or “B” shaped beams) or define an open channel (for example, “C” or “L” or “Z” or “I” shaped beams), and the pickup device and the cutter device are adapted to receive the beam as a position of the beam changes dramatically as the beam exits a roll former due to the different longitudinal sweeps. In tubular beams (and potentially in open channel beams), the cutter device  61  includes a wall-supporting member  68  ( FIG. 10 ) that clamps against sidewalls and lower face of beam  56  (as oriented when exiting the roll mill  54 ) immediately prior to actuation of the cutoff blade  64 . 
     In still another aspect, a method includes providing a roll former  54  for roll forming a sheet of material  52  into a continuous beam  56 , and providing a rapidly-adjustable power sweep unit  55  in-line with the roll former  54  for sweeping the continuous beam  56  into a curvilinear shape having longitudinal sections with at least two different sweeps S 1  and S 2  at selected locations. Further, the method includes providing a cutoff unit  57  in-line with the roll former  54  for cutting the continuous beam  56 , the cutoff unit  57  including an extendable pickup member  66  for engaging the continuous beam  56  to temporarily move the cutoff unit  57  along with the continuous beam  56  and including a guillotine-type cutoff blade  64  for cutting a beam segment  58  of predetermined length from the continuous beam  56 ; and controlling coordinated cyclical adjustment of sweep unit  55  and coordinated actuation of the cutoff unit  57  such as by using a programmable controller  59  to cause the beam segments  58  to have a desired length and to have the at least two different sweeps S 1  and S 2  at desired locations along the desired length. The controller  59  is programmed to coordinate movement and action of the roll former  54 , the sweep unit  55 , and the cutoff unit  57 , as well as other components associated with the apparatus  50 . 
     The counterbalance  65  ( FIG. 1 ) includes a pair of telescoping (tubular) guide members  70  and  71 . The top guide member  70  is pivotally attached to and supported by an overhead bracket  72  secured to a stationary object, such as a roof truss or the like. The bottom tubular guide member  71  is attached to cutoff-unit-supporting lower bracket  73 , which is pivoted to the cutoff unit  57  at a pivot  75  located approximately at the center of gravity of the cutoff unit  57 . Two counterbalance biasing devices, such as actuators  74 , are positioned on opposing sides of the tubes  70  and  71 . The illustrated biasing devices/actuators  74  include a cylinder and extendable rod, and are pressurized/powered to provide a vertical lift approximately equal to a total “active” weight being carried—which includes a lower portion of the counterbalance  65 , the lower bracket  73 , the cutoff unit  57 , and a portion of the continuous beam  56  extending from the sweep unit  55 , as well as a weight of cutoff return actuators  76  for returning the cutoff unit  57  to its home position. 
     The lower bracket  73  includes a top brace  77 , a cross brace  78 , downward leg braces  79  on each side, and forward leg braces  80 . The forward leg braces  80  are connected to the cutoff unit  57  at center-of-gravity pivot  75 . Notably, cutter device  61  includes an actuator and cutoff blade positioned to one side of the cutoff unit  57 , which causes its center of gravity to be offset laterally from the continuous beam  56  (when viewed from above). As a result, the top brace  77  and counterbalance components  70 - 72 ,  74  are located in a laterally offset position in a sideways direction in order to be closer to the actual center of gravity of the cutoff unit  57 . 
     The return actuators  76  for the cutoff unit  57  are positioned on opposing sides, and each include an extendable rod  82  pivoted to the side frame  83  of the sweep unit  55 , and include a cylinder  84 . The cylinder  84  includes a bracket  85  attaching it to the leg braces  80  at pivot  86 . The controller  59  is programmed and operably connected to the actuators  76  (e.g. via a hydraulic circuit including valves) to cause the actuators  76  to assist in returning the cutoff unit  57  to its home position adjacent the cutoff unit  57  after a cut has been made. Also, the controller  59  can be programmed to utilize the actuators  76  to facilitate movement in a downstream direction if desired (e.g., when the pickup device  60  is being actuated to extend the pickup pin  66 , or has been actuated). 
     The pickup device  60  ( FIG. 3 ) includes a box-like carriage frame  89  ( FIG. 7 ) and a pickup pin-and-actuator subassembly  90  ( FIGS. 8-9 ) slidably mounted thereon. The carriage frame  89  ( FIG. 7 ) includes side panels  91  and  92 , transverse braces  93 , upstream transverse axles  94  and  95  that support upper and lower beam-engaging upstream rollers  96 , and downstream rear transverse axles  97  and  98  that support upper and lower beam-engaging downstream rollers  99 . The lower axles  95  and  98  (or the upper axles) are vertically adjustable. The rollers  96  and  99  rollingly engage top and bottom surfaces of the continuous beam  56 , such that the carriage frame  89  allows the continuous beam  56  to slide therethrough when the frame  89  is stationary, and also such that the carriage frame  89  can roll in an upstream direction on the continuous beam  56  after a cut (i.e., as the frame  89  is moving toward its home position adjacent the sweep unit  55 ). 
     Various items are attached to the carriage frame  89 , such as the shock absorber  67  (attached to the downstream end), side bearing blocks  100  (attached to side panels  91  and  92 ), an anchor bracket  101  (for attachment to the adjustable link  63 ), and a transverse hole  102  (for attachment to the cutoff device  61  at the pivot  62 ). The shock absorber  67  can be any one of a variety of different things, such as a resilient rubber block or a friction-piston shock absorber with spring-, air-, or fluid-containing components. The side panels  91  and  92  each include a first window  103  for receiving the extendable pickup pin member  66 , and an elongated slot  104  below the window  103  for defining a track. 
     The pin-and-actuator subassembly  90  ( FIGS. 8-9 ) includes a side plate  105  and bottom plate  106  secured together in an L-shaped arrangement. The bottom plate  106  includes rollers  107  (or bearings) for rolling along the slots  104 . An actuator  108 , such as a pneumatic-, hydraulic-, or electromechanically-driven cylinder, is attached to side plate  105  and includes a block  109 . The illustrated block  109  does not slide on the edges of window  103 . Its function is to guide pin  66 . Block  109  is attached to block  105  which allows for vertical adjustment of pin  66 . The pickup pin member  66  extends from the block  109 . Rollers  110  are provided on the plates  106  for engaging plates  91  and  92  to guide the subassembly  90  in a longitudinal direction. The illustrated bearing block  109  also does not engage a side of the beam  56 . Adjustment devices, such as adjuster devices  111 - 113  and shock absorber stop  114 , are provided for adjusting a position of components on the subassembly  90  and on pickup device  60 . 
     In operation, the continuous beam  56  extends through the carriage frame  89  until the controller  59  senses a position of a locating hole(s) in the continuous beam  56 , such as by photo sensors or other sensors at the sweep station (or in other places along the apparatus  50 ). When the locating hole is sensed, the smaller-radius sweep S 2  is in an appropriate location, the pickup pin  66  is extended by the actuator  108  into the locator hole in the continuous beam  56 , and the cutoff unit  57  begins to temporarily move with the continuous beam  56 . The initial shock of engagement is dampened by the shock absorber  67  engaging a side of the pin-and-actuator subassembly  90  as the subassembly  90  moves a short distance on the carriage frame  89 . After the cutter device  61  operates, the pin  66  is retracted, and the actuators  84  return the cutoff unit  57  to a home position, potentially assisted by gravity as the carriage frame  89  rolls along the uncut portion of the continuous beam  56 . The shock absorber  67  also assists in biasing the pin-and-actuator subassembly  90  to its upstream position on the carriage frame  89 . It is contemplated that an additional actuator can also be provided to perform this function if necessary. 
     The cutter device  61  ( FIG. 10 ) includes a subframe  115  defining a cutting chamber and includes upstream and downstream plates  116  and  117  defining upstream and downstream enlarged apertures  118  for receiving the moving and waving continuous beam  56 . The apertures  118  are sized to receive the beam  56  regardless of where the sweeps S 1  and S 2  are located . . . keeping in mind that the cutter device  61  is normally stationary but intermittently moves as a unit with the pickup device  60  by pivot  62  and link  63 . Additional plates and structure are added to complete the subframe  115 , including right and left side plates  120  and  126 , bottom plate  122 , and top plate  123 . A clamp actuator  124  is mounted to the bottom plate  122  and is attached to a movable wall-supporting external mandrel  68  guided by wear plates on block  126  to engage a bottom of the continuous beam  56  at the time of cutting the beam  56 . A similar arrangement can be provided for engaging a top of the beam  56 , or the walls of the beam  56  can be supported during cutting by other structure, such as supporting top wall and protrusions  127  on the plate  116 . A guard  130  extends from under the cutting chamber and is configured to protect proximity switches on the cutoff  20  from being damaged. The scrap exits through an opening  151  between blocks  126 . (The flow of strips can be assisted by air blasts or vibration if necessary, but movement of the cutoff unit  57  normally combines with gravity to provide sufficient flow of scrap.) Anchor brackets  131  and  132  are provided for attachment at pivot  62  and to link  63 . An anchor bracket  133  is provided for defining the hole located at the center of gravity pivot  75 . 
     The cutoff blade  64  and its actuator  141  ( FIG. 10 ) are attached to the side plate  120  and includes a blade box guide  135  for guiding movement of the cutoff blade  64 . The blade box guide  135  includes opposing end plates  136  and  120 , guide posts  138  and  139  with slots  140  therein for guiding sliding movement of the cutoff blade  64 , and tie rods  137  for holding the end plates  136  and  120  together. An actuator  141  is mounted to and extends laterally from the outer end plate  136 , and includes a cylinder  141  and an extendable rod (not visible) connected to the cutoff blade  64  by a guillotine blade connector plate  143 . Straps  144  connected between the tie rods  137  ( FIG. 4 ) hold for proximity switches that sense the cutoff blade position. The actuator  141  is operably connected to a pressure line and valving operated by the controller  59  for timed actuation. 
     It is contemplated that the present sweep unit  55  can be positioned to sweep the continuous beam  56  horizontally in a sideways direction instead of vertically. Concurrently, it is contemplated that the present cutoff unit  57  can be positioned 90 degrees from its illustrated orientation (i.e. with the actuator  141  extending vertically and the cutoff blade  64  being extended vertically downwardly during its cutting motion). In such case, the entire cutoff unit  57  can be slidably supported on a horizontally-extending flat-surfaced table top for horizontal back-and-forth movement as the continuous beam  56  is given different sweeps S 1  and S 2 . In such case, the sweeps S 1  and S 2  extend in a horizontal plane parallel the flat table. 
     It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.