Abstract:
An adjustable forming assembly for molding laminate sheet material against a curved edge of a core. A plurality of wheels or other pressure members are arranged in an angular relationship so as to define the radius of curvature that matches the curved edge of the core. The pressure members move alternately towards and away from one another so as to selectively decrease and increase the radius of curvature to match curved edges of cores having different radii. The supports for the roller wheels are mounted to first and second frames that are moved together and apart by a drive mechanism, with the wheel supports being mounted to the first frame for radial movement and to the second frame for transverse movement, so that the wheel assemblies move together and apart while maintaining the same angular relationship. The adjustable forming assembly may be included in a  ______ -type laminate post-forming machine.

Description:
BACKGROUND  
         [0001]    a. Field of the Invention  
           [0002]    The present invention relates generally to methods and apparatus for post-forming a laminate sheet to a core formed of wood or other material, and, more particularly, to an assembly for use in a flow-line post-forming machine, the assembly being selectively adjustable to form laminate material to edges of differing radii.  
           [0003]    b. Related Art  
           [0004]    Post-forming machines are used to form the rounded edges of laminate countertops, such as those that are commonly used in kitchens, bathrooms, and so on. A core is provided which has a rounded edge, and the laminate material is applied over this and bent and adhered to the radiused corner, this process being referred to as “post-forming.” As used herein, the term “core” means any suitable base layer for use in such a construction, including, for example, a layer of wood, chip wood, plywood or MDF etc. The term “laminate”, in turn, includes any sheet material that may be applied to a core in such a construction, including, for example, plastics, melamine, wood veneers and metallic laminates. FIG. 1 shows an exemplary section of countertop  10  having this general construction. As can be seen, the core  12  is a comparably thick layer formed of chipboard or other suitable material, while the laminate  14  typically forms a comparatively thin layer that is installed on top of the core. The core is formed with a curved, smoothly radiused outer edge  16 , which is important from the standpoint of appearance, durability and user comfort. The laminate layer is bent in conformance with the curved edge of the core, so as to form a seamless, radiused outer surface  18  on the edge of the countertop.  
           [0005]    To form a laminate of about a core having a curved edge such as that which is shown, it is traditional that the laminate is first cut in accordance with the core shape, as is shown in FIG. 2, and an adhesive is applied to the laminate and/or core surface, as indicated by arrows  20 ,  22 . The laminate is then bonded to the flat upper surface of the core, with a portion  24  overlapping the core edge. The core and laminate are then placed on a post-forming machine which heats and softens the overlap so as to allow it to bend without cracking, as indicated at  26  in FIG. 2. The forming roller assembly in the post-forming machine, as is indicated schematically at  28 , then rolls the overlap so as to press the laminate into permanent contact with the profiled edge of the core.  
           [0006]    Post-forming can be performed using a machine which holds the core and laminate in a stationary position, or using a flow-line type machine in which the core and laminate move longitudinally through the machine as the above steps are applied in a sequential fashion. The flow-line type machines tend to be superior in terms of production efficiency, and it is to this type of machine that the present invention is directed.  
           [0007]    A number of different flow-line type post forming machines are available on the market. In general, these use forming roller assemblies made up of a series of rollers that are arranged to press sequentially against the overlapped edge of the laminate material, thereby gradually bending the edge of the laminate into contact with the curved edge of the core.  
           [0008]    A problem with the existing types of roller assemblies used in flow-line type post- forming machines is their lack of easy adjustability. For example, different types and styles of countertops may have edges with different radii, i.e., one counter-top may have a large radius which provides a gently rounded edge, while another may have a small radius which produces a comparatively sharp 90° edge. Existing types of forming roller assemblies, however, can usually be set for only a single radius; when a core having a different edge radius is placed in the post-forming machine, the forming roller assembly must be readjusted, modified and/or changed out to match the new radius. In order to do this, the machine must be stopped, and the roller mounts must be adjusted and reset individually, since no change can be made while the machine is in operation. This is a costly and time consuming procedure, during which the machine is “down” and taken off the production line for an extended period, not only because of the difficulty of making the actual adjustments, but also because the machine must be allowed to cool before working on the forming roller assembly. Accordingly, there exists a need for a forming assembly for use in a flow- line type post-forming machine that can be adjusted quickly and easily to form laminate to edges of cores having different radii. Furthermore, there exists a need for such a forming assembly that can be adjusted without causing a significant interruption in the operation of the post-forming machine. Still further, there exists a need for such a forming assembly that can be mounted in existing types of flow-line type post-forming machines without requiring significant structural modification thereof. Still further, there exists a need for such a forming assembly that is comparatively inexpensive to construct and durable in service. Still further, there exists a need for such a forming assembly that can be operated by either manual or remote/automated means.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention has solved the problems cited above, and is an adjustable forming assembly for use in a flow-line type laminate post-forming machine. Broadly, this comprises a plurality of pressure assemblies for pressing laminate material into conformity with a curved corner of a core, the pressure assemblies being arranged in a predetermined angular relationship so as to define a radius of curvature which corresponds to the curved corner of the core material, and means for selectively moving the pressure assemblies alternately towards and apart from one another while maintaining the predetermined angular relationship, so as to selectively decrease and increase the radius of curvature which is defined thereby to correspond to curved corners having smaller and larger radii.  
           [0010]    Preferably, the pressure assemblies are roller wheel assemblies and the wheel assemblies are configured to extend normal to the curved corner of the core as the laminate is pressed against the corner thereby.  
           [0011]    In a preferred embodiment, the forming roller assembly comprises a first frame member which is disposed towards the curved corner of the core and which includes means for mounting each of the wheel assemblies for radially slideable movement relative thereto, a second frame member which is disposed away from the curved corner of the core and which includes means for mounting each of the roller wheel assemblies for transverse movement relative thereto, and means for selectively moving the first and second frame members towards and away from one another so as to shorten the distances between the mounting means thereon, so that the roller wheel assemblies move together and apart in response to the movement of the frame members while maintaining the predetermined angular relationship of the wheel assemblies.  
           [0012]    The means for selectively moving the first and second frame members towards and away from one another may comprise a stationary frame member, means for selectively moving the first frame member towards the stationary frame member, and means for holding the second frame member in a stationary position relative to the stationary frame member. The means for holding the second frame member stationary relative to the stationary frame member may comprise a fixed length actuating arm having an upper end which is mounted to the stationary frame member, at least one rotatable gear which is mounted to the first frame member and which is connected to the lower end of the actuating arm for rotation thereby, and at least one gear rack which is mounted to the second frame member and which is in operative engagement with said at least one rotating gear member for moving the second frame member in an opposite direction relative to the first frame member as the first frame member moves towards and away from the stationary frame member. The means for selectively moving the first frame member towards and away from the stationary frame member may comprise a threaded shaft, which is rotatably mounted to the stationary frame member, and a sliding member which is fixedly mounted to the first frame member and which is in threaded engagement with the rotatable shaft. A hand wheel may be mounted on the threaded shaft for manual rotation thereof, or a motor may be provided for rotation of a shaft in response to remote or automatic control.  
           [0013]    The means for mounting the roller wheel assemblies to the first frame member may comprise a plurality of tee-rails for engaging corresponding tee-slots in the wheel assemblies, the tee-rails being mounted to the first frame member in radial alignment with the pre-determined radial relationship of the wheel assemblies. The means for mounting the roller wheel assemblies to the second frame member may comprise a plurality of U-track members which engage corresponding sliding bearing members on the wheel assemblies, each U-track member being mounted to extend perpendicular to the axis of the corresponding tee-rail to which the wheel assembly is mounted. The sliding bearing member may comprise a roller bearing that is mounted to an upper end of the wheel assembly.  
           [0014]    Each wheel assembly may comprise an elongate support member having the tee-slot formed therein, with the sliding bearing member being mounted to the upper end of the support member and the roller wheel being mounted to the lower end thereof. The roller wheel may be provided with a spring suspension for resiliently biasing the wheel against the surface of the laminate, and the spring suspension may comprise a torsion spring by which the wheel is mounted to the lower end of the elongate support member. These and other features and advantages of the present invention will be apparent from a reading of the following detailed description with reference to the associated drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a perspective view of a section of laminated counter-top material, showing the laminate sheet bonded to the core in conformance with the rounded outer edge thereof;  
         [0016]    [0016]FIG. 2 is a schematic view showing the sequential steps in the assembly and manufacture of the laminated counter-top material of FIG. 1;  
         [0017]    [0017]FIG. 3 is a front, elevational view of a forming roller assembly in accordance with the present invention, showing the manner in which the assembly positions the forming wheels thereof relative to the profiled edge of the core;  
         [0018]    [0018]FIG. 4 is a side, elevational view of the forming roller assembly of FIG. 3, showing the longitudinal arrangement of the roller wheels for sequentially pressing the laminate against the profiled edge of the core;  
         [0019]    [0019]FIG. 5 is a perspective view of the roller wheel units of the forming roller assembly of FIGS.  3 - 4 , showing the wheel units in the relative positions and angles in which they are mounted in the assembly;  
         [0020]    [0020]FIG. 6 is a perspective view showing the rotatable handle and pivoting gears of the forming roller assembly that actuate movement of the roller wheel units for radial adjustment of the assembly;  
         [0021]    [0021]FIG. 7 is a perspective view of the gear racks of the forming roller assembly that cooperate with the pivoting gear segments shown in FIG. 6 to effect movement of the roller wheel units;  
         [0022]    [0022]FIG. 8 is a perspective view of the frame within the forming roller assembly which supports the gear racks and rail of FIG. 7 for movement relative to the pivoting gear segments of FIG. 6; and  
         [0023]    [0023]FIG. 9 is an end, schematic view showing the positional and angular relationship of the roller wheel units of the forming roller assembly when adjusted to a first edge profile having a comparatively large radius and a second edge profile having a comparatively small radius.  
     
    
     DETAILED DESCRIPTION  
       [0024]    The present invention provides a forming roller assembly that is mountable in existing types of flow-line post-former machines with a minimum of structural modification thereto. The assembly is quickly and easily adjustable by rotating a screw mechanism, either using a manual hand wheel or a suitable drive motor, so that the screw mechanism actuates a cooperating gear linkage to move individual roller wheel units towards or away from one another while maintaining their angular relationship so as to change the corner radius which is defined thereby.  
         [0025]    A preferred embodiment of the invention will be described below with reference to the principle sub-assemblies thereof, followed by a description of the manner in which these subassemblies cooperate to adjust the radius that is defined by the wheel units.  
         [0026]    a. Stationary Frame  
         [0027]    [0027]FIG. 3 shows a forming assembly  110  in accordance with a preferred embodiment of the invention. As can be seen, this includes a stationary frame assembly  112  having a base plate  114 , which is mountable to the frame of the post-forming machine. A frame plate  116  is mounted to the base plate  114 , together with a welded gusset  118  for rigidity, and this supports a rotatable actuator shaft  120  at an approximate 45° angle with respect to the horizontal core. In the embodiment which is illustrated, a manual adjuster wheel  124  and crank handle  126  are mounted to the upper end of the actuator shaft, although it will be understood that in other embodiments the actuator shaft may be rotated by a motor or other mechanism, either manually or automatically controlled. The actuator shaft can be rotated at any time in order to adjust the forming radius of the assembly (as will described in greater detail below), without needing to take the post-forming machine off the production line or having to allow it to cool.  
         [0028]    As can be seen in FIG. 4, the upper end of the actuator shaft is mounted so as to be freely rotatable, but longitudinally stationary, within a corresponding bore in a face plate  128  which is mounted transversely to the upper end of plate member  116 . The lower end of the actuator shaft, in turn, is provided with threads  130 , and is in threaded engagement with a cooperating bore in slider block  132 . The slider block is fixedly mounted (e.g., welded) to a sliding actuator rail  134  (see also FIG. 3) that is received for longitudinally movement in an inverted channel  136  formed in the bottom of a guide member  138 , the latter being mounted to the upper edge of the frame plate  116 .  
         [0029]    The actuating rail and guide channel extend parallel to the rotatable shaft (i.e., at a 45° angle to horizontal), and the face plate  128  is fixedly mounted to the upper end of the frame plate  116 . Thus, by rotating the adjustment wheel  124  first one way and then the other, the actuating rail  134  is moved alternately inwardly and outwardly relative to the stationary frame assembly  112 , along an axis parallel to that of the actuator shaft  120 .  
         [0030]    b. Moving Frame  
         [0031]    As can be seen in FIG. 8, the sliding rail  134  forms a part of the moving frame assembly  140 , the lower end of the rail being welded or otherwise fixedly mounted to the a transverse support plate  142 . Accordingly, it will be understood that frame assembly  140  will move alternately towards and away from the stationary frame  112  as rail  134  retracts and extends in response to rotation of actuator shaft  120 .  
         [0032]    A series of tee-rails  146   a - e  ( 146   e  not being visible in FIG. 8) is mounted along the upper edge of plate  142  for supporting the individual roller wheel units  150   a - e  (see FIG. 5) in sliding engagement therewith, as will be described in greater detail below. First and second guide sleeves  152   a,    152   b  are also formed in support plate  142 , for supporting first and second guide rods  154   a,    154   b  on gear rack assembly  160  in sliding engagement therewith, as will also be described in greater detail below.  
         [0033]    Finally, a lower support plate  162  is welded or otherwise secured in overlapping relationship to the main support plate  142  so as to extend generally downwardly and parallel to the main support plate. As can be seen, the two support plates cooperate to define an elongate opening  164  for receiving the pivoting gear assembly  170  (see FIG. 6). Bores  172  are provided proximate the ends of the opening for receiving the mounting bolts (not shown) which secure the pillow blocks  174   a,    174   b  at the end of the gear assembly to lower support plate  162 .  
         [0034]    c. Rotating Gear Assembly  
         [0035]    As was noted above, and as is shown in FIG. 6, the pillow blocks  174   a,    174   b  of the rotating gear assembly  170  are mounted to the lower plate of the moving frame assembly. The pillow blocks support the ends of an elongate shaft  176  in rotating engagement, with a bell crank  178  being fixedly mounted to the shaft near its center. The outer end of the bell crank is mounted to the end of a fixed-length actuating arm  180  by a pivot connection  182 , with the upper end of the arm being attached to a support bracket  184  on the stationary support frame  112  by a second pivot connection  186 . Thus, as the moving frame assembly  140  moves inwardly and outwardly relative to the stationary frame assembly  112  in the manner which has been described above, the fixed length actuating arm  180  causes the shaft  176  of the rotating gear assembly to rotate alternately towards and away from the profiled edge of the core, as indicated by arrows  190  and  192 .  
         [0036]    Gear segments  194   a,    194   b  are mounted on the ends of shaft  176  so as to rotate together therewith, and are in operative engagement with corresponding gear racks  195   a,    195   b  on the sliding frame assembly  160 . Rotation of the shaft/gear segments thus causes the sliding frame assembly to move inwardly and outwardly with respect to the moving frame assembly  140 , as will be described in greater detail below. As can also be seen in FIG. 8, slots  196   a,    196   b  are provided to accommodate rotation of the gear segments relative to the support plates of the moving frame assembly  140 .  
         [0037]    d. Sliding Frame Assembly  
         [0038]    As can be seen in FIG. 7, the sliding frame assembly  160  includes a main cross-bar  200  to which the guide rods  154   a,    154   b  and gear racks  195   a,    195   b  are fixedly mounted in parallel, spaced-apart relationship. As was described above, the guide rods  154   a,    154   b  cooperate with the guide bushings  152   a,    152   b  in the moving frame assembly  140  so as to slide therethrough, while the gear racks  195   a,    195   b  engage the teeth of the gear segments  194   a,    194   b  of the rotating gear assembly  170 .  
         [0039]    Thus, motion of the moving frame assembly  140  away from the stationary frame assembly  112  (as the rail member  134  extends in response to rotation of the hand wheel) causes the gear shaft to rotate in the direction indicated by arrow  190  in FIG. 6, thereby drawing the sliding frame assembly towards the stationary frame assembly, in the direction indicated by arrow  202  in FIG. 7. Rotation of the hand wheel in the opposite direction causes the moving frame assembly  140  to retract towards the stationary frame assembly  112 , so that the sliding frame assembly  160  is driven downwardly by the gears and away from the stationary frame assembly, in the direction indicated by arrow  204 . In other words, the sliding frame assembly  160  moves in the opposite direction from the moving frame assembly  140  as the adjustment shaft is rotated in one direction or the other, the net effect being that the sliding frame remains in an essentially stationary position relative to the stationary frame  112  as the moving frame moves towards and away from the latter.  
         [0040]    As can be seen with further reference to FIG. 7, a series of support arms  206   a - e  is also mounted to the cross-bar  200  in spaced-apart, generally parallel relationship, at an approximately 90° angle to the guide rods  154   a,    154   b  and the gear racks  195   a,    195   b.  The first arm member  206   a  is the longest and is located towards the front of the assembly, i.e., towards the side from which the laminate and core enter the forming roller assembly, and the remaining arms  206   b - e  are progressively shorter.  
         [0041]    Identical U-channel members  208   a - e  are mounted to the outer ends of the arm members  206   a - e,  each of which is configured to engage and retain a corresponding bearing roller  210  on the upper end of an individual wheel assembly  150  (see FIG. 5). Outward and inward forces on the wheel assemblies (e.g., the vertical pressures which are transmitted into the assembly as the wheels force the laminate towards the core material) are thus transferred into the upper and lower walls of the U-channels  208 - e,  and from there through support arms  206   a - e  into the main cross bar  200  of the sliding frame assembly. Furthermore, each U-channel member cooperates with the bearing roller to define a travel path which extends in a direction perpendicular to the associated tee-rail  146  to which the assembly is mounted, and which permits the assembly to accommodate the transverse movement which develops between the wheel assemblies as the frame assemblies  140  and  160  move inwardly and outwardly relative to one another.  
         [0042]    e. Wheel Assemblies  
         [0043]    [0043]FIG. 5 shows the series of identical wheel assemblies  150   a - e  that are mounted in the forming roller assembly. As can be seen with reference to wheel assembly  150   a,  each assembly includes an elongate support member  212  having a tee-slot  214  formed in the forward side thereof. The tee-slot is configured to engage the corresponding tee-rail on the moving frame  140  so as to permit the wheel support to slide upwardly and downwardly thereon while maintaining a constant angular alignment (as defined by the tee-rail), and the tee-rails also absorb the “drag” force which is transferred into the assembly as the wheels move over the laminate.  
         [0044]    As was noted above, a bearing roller  210  is mounted to the top of each of the wheel supports, by means of a bearing holder  216 , so that the roller faces in a forward direction for being received in its U-channel member. A roller wheel  220 , in turn, is mounted to the bottom end of each wheel support, preferably using a spring suspension that biases the roller wheel against the laminate material. In the embodiment that is illustrated, the axle  222  of the roller wheel is connected to a torsion spring mechanism  224  by a pair of rearwardly angled side-plates  226   a,    226   b  and a mounting pin  228 . Thus, the roller wheels are held firmly yet yieldingly against the laminate so as to provide the pressure necessary to force the laminate into conformance with the edge of the core.  
         [0045]    Although roller wheels are employed in the preferred embodiments of the present invention, it will be understood that other forms of pressure members may be used in place of or in addition to the roller wheels, such as sliding skids or spring-loaded shoes, for example.  
         [0046]    f. Angular Relationship and Operation  
         [0047]    As can be seen in the figures, particularly in FIGS. 3 and 5- 8 , the wheel assemblies and movable components of the assembly are arranged in radial alignment about a common center. In the five-wheel assembly that is shown in the drawings, the roller wheels define an approximate 60° arc around the common center; it will be understood, however, that in other embodiments there may be more or fewer wheel assemblies, and they may describe a larger or smaller arc than that which is shown herein.  
         [0048]    As was noted above, the threaded adjustment shaft and sliding support  134  are aligned at an approximate 45° angle (assuming that the core is aligned in a generally horizontal plane). This angle is represented by the axis “A-A” in FIG. 9, and it will be seen that the middle wheel assembly  150   c  is also aligned with this axis. The wheel assemblies  150   a,    150   b  in front of this are aligned at incrementally greater angles (i.e., roller wheel  150   b  is aligned approximately 60° above horizontal, and roller wheel  150   a  is aligned at approximately 75°), while the following wheel assemblies are aligned at incrementally lower angles (i.e.,  30 ° above horizontal for  150   d,  15° for  150   e ). These relative angles are fixed, due to the fixed angular relationship of the tee-rails  146   a - e  on the moving frame assembly  140 . As was noted above, however, the wheel assemblies are free to move laterally relative to the sliding frame assembly  160  by virtue of the U-channel members  208   a - e,  which are aligned at 90° angles to the tee-rails.  
         [0049]    Thus, referring to FIGS. 3 and 9, when hand wheel  124  is rotated in the clockwise direction, the moving frame  140  is pulled upwardly towards stationary frame  112 . This causes the actuating arm  180  to rotate the gear assembly, so that gear segments  194   a,    194   b  cooperate with gear racks  195   a,    195   b  to move the sliding frame  200  downwardly towards the moving frame  140 , thus forcing the wheel assemblies out of the moving frame (i.e., towards the lower left corner in FIG. 9) and causing a shortening of the distance between the tee-rails  212   a - e  and the U-channel members  208   a - e.  The angular relationship of the U-channel members ensures that the wheel assemblies move the same amount of distance simultaneously as this is done. For example, at a ratio of approximately 1:4:1, 1.4 inch movement of the moving frame  140  into the stationary frame  112  produces about 1.0 inch of movement of the central wheel assembly in the opposite direction, due to about 0.4 inch upward movement of the rotating gear assembly itself.  
         [0050]    As a result, the wheel assemblies move from a relatively spread-apart configuration in which they define a comparatively large radius forming R 1 , as is shown in FIG. 9, to a “bunched together” configuration in which they define in comparably small forming radius R 2  Reversing the direction of rotation of the hand wheel (i.e., rotating it in the counter-clockwise direction) forces the wheel assemblies back apart, so that these again define a comparatively large forming radius R 1 . Viewed another way, since the angular relationship between the wheel assemblies remains constant, the common radial center which is defined by the wheel assemblies is closer to the corner of the core when the assemblies are brought together by the apparatus, and is further from the corner when they are spread apart.  
         [0051]    Since the central wheel assembly  150   c  remains in an essentially stationary position relative to the other wheel assemblies as the latter move inwardly and outwardly relative thereto, it will be understood that in some embodiments the central roller wheel assembly (i.e., that wheel assembly which extends parallel to the primary axis of adjustment) may be hard-mounted within the assembly, rather than riding on a tee-rail and U-channel member as is shown herein. The illustrated embodiment, however, has the advantage of using standardized components for all of the wheel assemblies, which tends to facilitate and reduce the cost of manufacture.  
         [0052]    For ease of illustration, FIG. 9 shows the wheel assemblies (and the radii which are defined thereby) in their positions relative to the moving frame assembly  140 . As was described above, the moving frame assembly  140  which moves inwardly and outwardly relative to the stationary frame and the core material while the wheel assemblies remain in the area where they press against the corner of the core.  
         [0053]    It is to be recognized that various alterations, modifications, and/or additions may be introduced into the constructions and arrangements of parts described above without departing from the spirit or ambit of the present invention. For example, the tee-slots and rails and U-channels described above may have other suitable interfitting configurations for holding and guiding their respective members. Furthermore, although the preferred embodiment described above employs screw and gear mechanisms to provide the motions of its components, it will be understood that hydraulic, pneumatic, or other forms of drive mechanisms may be used to provide corresponding motions in other embodiments of the invention. The invention is therefore to be limited only by the appended claims.