Abstract:
Apparatus and method for crimping the side walls of a sheet metal building panel independently of a main crimper which crimps the belly of the panel. The depth and the position along the panel of the side crimp is adjusted independently of the main crimpers in relation to the radius the panel is being curved and the length of panel that has passed through the apparatus. The adjustment is controlled by a microprocessor. The microprocessor controls a hydraulic motor which drives a machine screw which activates a scissors-jack type linkage. Blocks holding the rotatably mounted crimping rollers are mounted on slides and attached to the linkage. As the linkage moves, the depth of the crimping rollers is adjusted. The rotation of the crimping rollers is hydraulically driven through a gear-sprocket rotary motion drive train.

Description:
This application is a Reissue of Ser. No.  08 / 425 , 440 , filed Apr.  20 ,  1995 , now U.S. Pat. No.  5 , 584 , 198 , issued Dec.  17 ,  1996 . 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to machines and methods for forming metal panels for constructing metal buildings, and more particularly relates to apparatus and methods for forming curved building panels from flat sheet metal material by crimping. 
     2. Background and Prior Art 
     It is known in the prior art to construct metal buildings from metal panels which are arched or curved, assembled side-by-side and seamed together. See U.S. Pat. No. 3,902,288 to Knudson. In such buildings the roof panels continue as the side walls of the building and the basic building construction is in the shape of a self-supporting continuous arch or semicircle when viewed from one end. A machine for making the building panels in which U-shaped panels are corrugated or crimped both on the bottom or “belly” and on the sides to create the curvature is shown in U.S. Pat. No. 3,842,647 to Knudson. 
     An arched building construction in which the walls and roof are completely arched has advantages, but also has a number of limitations. One limitation is the absence of vertical walls which limits the use of vertical space. Users of metal buildings often want vertical walls both for aesthetic purposes as well as to obtain the use of more vertical space near the edges to the building. The basic size and strength of such metal buildings is also limited by wind and live load limitations as established by local and national building codes. A completely arched building must be limited in size in order to prevent overloading as could occur from extensive wind loads produced by hurricanes. However, when the total roof height is reduced to approximately one-fifth of the total building width, hurricane force winds do not affect the building as much because of the reduced frontal area. 
     Improvements to the above technology are disclosed in U.S. Pat. Nos. 5,249,445 and 5,359,871 to Morello, incorporated by reference herein in their entirety. These patents disclose microprocessor-controlled methods and apparatus wherein metal building panels could be formed by automatically controlling the radius of curvature and wherein the panels may have a straight as well as a curved portion so that metal panel buildings could be constructed with arched roofs and vertical walls. The cited Morello patents disclose the use of hydraulics and microprocessor controlled machinery which forms U-shaped building panels of predetermined length from a coil of sheet metal. The formed panels are then continuously crimped on their side edges for strength and are adjustably curved by crimping the belly of the panel. The crimping is automatically controlled so that building panels may be formed with vertical wall portions and curved or arched roof portions. 
     A problem in the prior art, however, was the fact that the depth of the crimp on the side edges of the panel remained constant, even as the radius of the panel being curved changed. If the radius of the panel was tight, and the depth of side crimp was shallow, the side walls of the panel buckled due to the excess material not taken up by the crimp. Analogously, if the radius was large or the panel section being formed was straight, and the depth of side crimp was deep, the belly of the panel buckled due to excess material in the belly not taken up by the crimping. Because of the physical distance between the side crimping apparatus and the main crimping apparatus, the simultaneous adjustment of the side and main crimping apparatus caused the length of panel between the side crimper and the main crimper during this adjustment not to have the change in depth of crimp on the side walls, which caused the buckling effect discussed above. Thus, there exists a need in the art for improvement to such apparatus and methods to eliminate the deleterious buckling effects caused by adjustment of the crimping mechanisms during formation of such panels. 
     SUMMARY OF THE INVENTION 
     The panel crimping apparatus and method of the present invention is unique in that the depth of crimp in the side portion of a metal building panel is controlled by a microprocessor and the side crimping rollers are adjusted independently of the main crimping rollers, according to the radius of panel being curved and the length of panel that has passed through the apparatus. The present invention thus eliminates the problem of metal panel buckling in the prior art when the radius of curvature of a building panel was varied during formation. 
     The crimping apparatus includes two sets of rotatably mounted panel side portion crimping rollers with the sets mounted vertically with respect to each other and the rollers mounted horizontally on shafts. The outside roller of each set is rotatably mounted on a shaft supported at both ends by stationary bearings. The inside roller of each set is rotatably mounted on a cantilevered shaft supported on only one end by bearings. The bearings of the cantilevered shaft are mounted in a non-stationary sliding block that is movable in the direction of the stationary crimping rollers, thus creating a change in the depth of crimp by changing the distance between the inside roller and the outside roller. The sliding mechanism consists of male and female V-grooved guide bars, with the male guide bar being attached to the sliding block and the female guide bar being attached to a main support plate. Extending through the center of the main plate is a machine screw which is supported on the reverse side of the main plate by a block that houses three angular-contact bearings. On this machine screw is a bronze nut that is attached to a block mounted horizontally in a plane at a right angle to the crimping rollers. This block is the center point for a scissors-jack type linkage that extends to each of the two non-stationary crimping roller blocks. The linkage is such that as the machine screw is rotated, the linkage center block moves along the screw to cause the non-stationary crimping roller blocks to slide in the direction perpendicular to the screw and thus change the depth of crimp. 
     Mounted on the opposite side of the machine screw is a universal joint which constitutes a coupling to a hydraulic motor. A linear encoder tracks the position of the center linkage block along the length of the machine screw and sends that information to a microprocessor. A rotary encoder tracks the length of panel that is being crimped by the apparatus and sends that information to the microprocessor. The rotation of the hydraulic motor that controls the depth of crimp is controlled by a valve that is controlled by the microprocessor. The microprocessor determines when to adjust the crimping rollers and to what depth based on the information received from the encoders. 
     Each shaft that supports the crimping rollers also supports a gear that fits into a drive train. This drive train is driven by a hydraulic motor separate from the motor that adjusts the crimping depth. The drive train motor controls the rotary motion of both the side crimping rollers and the main crimping rollers, and is also controlled by the microprocessor. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a preferred embodiment of the side crimper apparatus disconnected from the entire building panel forming machine and showing a portion of a panel midway through the side crimper; 
     FIG. 2 is a side view of the side crimper apparatus of FIG. 1 from the direction of entry of the panel; 
     FIG. 3 is an isometric view of the slide blocks and linkage arms of the side crimper apparatus according to a preferred embodiment of the invention; and 
     FIG. 4 shows an isometric view of the center linkage adjustment mechanism of the side crimper apparatus according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described in detail, referring to FIGS. 1-4. The panel  1  being crimped has a bottom or “belly”  10  and two sides  20  at 90 degrees to the belly. The panel feeds into the side crimping apparatus  30  in the orientation shown. There are inside crimping rollers  40  (FIG. 2) and opposing outside crimping rollers  50 . The rollers consist of a steel hub with blades welded radially around the perimeter of the hub so as to cause a corrugated crimp  21  in the sheet metal panel when it is passed through mating sets of rollers. The top outside crimping roller is rotatably mounted on a steel shaft  60  that is supported on both ends by bearings  62 . The bearings are mounted in a steel main plate  80  and an aluminum outside plate  90 . On the main plate side, the top shaft  60  continues through bearing  62  and supports a gear and sprocket which are components of rotary motion drive train  100 . The bottom outside shaft  70  differs from shaft  60  only in that it is not directly connected to drive train  100  but continues through the bearing housed in the outside plate  90  and supports a miter gear  72  that serves as a link to the main curver drive train (not shown), which powers the forward rotation of the crimping rollers  40  and  50 . The bottom shaft  110  is supported by a bearing at each end with one end continuing through the main plate bearing to support a gear and sprocket which are further components in the rotary motion drive train  100 . 
     The rotary motion drive train  100  is configured such that the top and bottom sets of crimping rollers rotate together to feed the panel  1  through the apparatus. The inside crimping rollers  40  are rotatably mounted on cantilevered shafts  42  which are supported only on one end by bearings  44  so as to allow the belly  10  of the panel to pass through the other side  46 . The bearings  44  are press fitted into aluminum slide blocks  48 . In each slide block  48  there are two bearings (not shown) mounted back to back to aid in supporting the load of the panel being crimped. 
     The shafts  42  continue through the slide blocks  48  and the main plate  80  to support gears that fit into the rotary drive train. Each edge of the slide blocks  48  holds a male guide bar  15  (FIG. 3) which slides vertically along a female guide bar  16 . The guide bars  15  and  16  are “V” grooved in shape. This causes the slide bars to be self-centering and to have a large contact area to aid in high load support. All edges of the male guide bar  15  are rounded to prevent them from catching or knifing into the female guide bar  16  as they are sliding. The female guide bars  16  are permanently attached to the main plate  80 . Both sets of guide bars are constructed of high strength, hardened steel that has an Armoloy plating. All of these features lead to a durable, low friction slide made to withstand high loads. 
     Mounting holes  33  in the female guide bars are slotted so as to allow the female guide bars to adjust closer to the male guide bars and ensure that they seat firmly together so as to take advantage of the self-centering properties of the “V” groove. Steel stiffener plates  17 , which are attached to main plate  80 , hold set screws  35  which tighten onto the backs of the female guide bars to perform this adjustment and to ensure that the guide bars will not slip back after the adjustment. The stiffener plates  17  also prevent the main plate  80  from flexing due to the loading. The inner ends of the slide blocks  48  have milled slots  34  which accommodate steel linkage arms  18 . The linkage arms are mounted at one end to the sliding blocks  48  using Teflon permeated plane bearings  19  which ride on high tensile strength precision ground shoulder bolts  39  so as to allow a pivoting motion of the linkage arms with respect to the sliding blocks. 
     The other end of the linkage arms  18  are connected to a steel, Armoloy coated center linkage block  51  (FIG. 4) via additional shoulder bolts. Center linkage block  51  has the male portion of a dovetail joint machined into both ends. The female portion of the dovetail joint is machined into two steel, Armoloy coated upright guide blocks  52 . The purpose of the Armoloy coating is rust prevention and an extremely hard, smooth surface to act as a bearing surface. The upright blocks  52  are solidly mounted to both the main plate  80  and the stiffener plates  17  for extra rigidity. This configuration allows the center linkage block  51  to travel only in a linear horizontal sliding motion, preventing the panel load from forcing the entire inside roller and slide block assembly along the vertical plane. 
     The center linkage block  51  houses a bronze acme-threaded bearing nut  23  (FIG.  4 ). Machine screw  24  travels through a clearance hole in the center linkage block  51 , a clearance hole in the main plate  80 , and into a set of three angular contact bearings  25  (FIG. 2) that are housed in an aluminum bearing block  26 . Angular contact bearings have the ability to support both axial and radial loads. Two of the three bearings are oriented to support an axial load in the direction towards the outside plate  90  and the third bearing is mounted opposite of the other two. The machine screw  24  is constrained from axial travel by a machined shoulder that rests against the third angular contact bearing on the side closest to the main plate  80 , and a threaded bearing nut  27  on the opposite side of main plate  80  to remove any axial play, ensuring an accurate system. 
     A universal joint  28  provides a rotary link between the machine screw  24  and a hydraulic motor  29 . As the machine screw  24  is turned by the motor  29 , the nut  23  causes the center linkage block  51  to travel axially along the machine screw. As the center linkage block  51  moves closer to the main plate  80 , the linkage arms  18  flatten vertically and push against the slide blocks  48 , causing them to slide along the guide bars toward the stationary outside crimper rollers  50 , thus moving inside crimper rollers  40  closer to rollers  50 , resulting in a deeper crimp. When the rotation of the machine screw is reversed, the center linkage block  51  travels away from the main plate  80 , pulling the linkage arms  18  with it. This causes the slide blocks  48  to be pulled down along the guide bars, moving inside rollers  40  away from the stationary crimper rollers  50 , resulting in a shallower crimp. 
     A microprocessor (not shown) controls the valves that control the hydraulic motor  29 . The microprocessor receives inputs from a rotary encoder  120  (FIG. 1) and a linear encoder  31  (FIG.  4 ). The rotary encoder measures the length of panel that has traveled through the apparatus. The linear encoder is linked through a stainless steel shaft  32  to the center linkage block  51 , enabling the encoder to track the linkage block&#39;s position along the machine screw and relay that information to the microprocessor. The microprocessor determines at what depth the side crimpers need to be at predetermined locations along the panel length, independently from the main crimpers. The aforementioned U.S. Pat. No. 5,359,871 discloses other capabilities and functions of the mentioned microprocessor. 
     The side crimper control function of the microprocessor has the ability to perform the following tasks: 
     enable/disable the entire side crimper adjust function; 
     determine the depth of crimp as a function of panel material thickness and radius at which the panel is being curved; 
     control the direction and start/stop of the hydraulic motor  29  to reach the desired depth of crimp; 
     control the speed of the hydraulic motor including a standard high and low speed; 
     set electronic safety stops for the maximum and minimum depth of crimp; 
     LCD readout of the rotary and linear encoder positions; and 
     determine the position along the panel to begin adjusting as a function of the type of panel being formed, the speed at which the curver is being run, and the total change of depth. 
     Of course, the microprocessor may be used to carry out many other functions in addition to those mentioned above. 
     The invention having been thus described, it will be apparent to those skilled in the art that the same may be varied in many ways without departing from the spirit and scope of the invention. Any and all such modifications as would be obvious to those skilled in the art are intended to be within the scope of the following claims.