Patent Publication Number: US-2009229503-A1

Title: Automatic miter machine

Description:
BACKGROUND 
     The preferred method of producing pillow-top mattresses is to have a mitered seam at the corners. Unlike other methods that restrict the depth of the gusset, mitering will produce the deepest and smoothest corners with any given materials. Gusset mitering has traditionally been a manual operation which often is quite tedious. The manual mitering operation typically requires a two-step procedure including sewing a V-shaped profile and cutting away the outer portion with scissors. The process can be slow and can present ergonomic challenges for operators. 
     SUMMARY 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     A first illustrative embodiment of the present invention relates to an apparatus for mitering portions of a workpiece to create mitered corners. The apparatus has a base assembly and an X-Y positioning table coupled to the base assembly. At least two clamp assemblies are coupled to the top of the positioning table for holding portions of a workpiece in place. A sewing machine is also coupled to the base assembly and is positioned adjacent the positioning table. The sewing machine is used to sew a series of lock stitches along a V-shaped path. A notching device is positioned downstream from the sewing machine and is used to remove a triangular-shaped portion of the workpiece to create a mitered corner. 
     A second illustrative embodiment of the present invention relates to a machine for creating mitered corners of a pillow-top mattress gusset. The machine has a base and a work surface coupled to the base. At least two sewing clamps are disposed on the work surface and a sewing device is positioned adjacent the work surface. A cutting device, including a triangular shear, is located downstream from the sewing device. A disposal device is located adjacent the cutting device for removing cut portions of a workpiece from the cutting device. The machine also has at least one controlling computer for synchronizing the operation of the various components. 
     A third illustrative embodiment of the present invention relates to a multiple-stage system for automatically sewing and notching portions of a gusset to create a pillow-top mattress gusset having mitered corners. The system includes a clamping component disposed on an X-Y table, a sewing component for sewing a series of stitches along a V-shaped path, a notching component for removing a triangular-shaped portion of a gusset, and a controlling computer for automating a multiple-stage mitering process. 
     These and other aspects of the invention will become apparent to one of ordinary skill in the art upon a reading of the following description, drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is described in detail below with reference to the attached drawing figures, wherein: 
         FIG. 1  is a perspective view of an apparatus for mitering portions of a workpiece in accordance with an embodiment of the present invention; 
         FIG. 2  is a front view of an apparatus for mitering portions of a workpiece in accordance with an embodiment of the present invention; 
         FIG. 3  is a side view of an apparatus for mitering portions of a workpiece in accordance with an embodiment of the present invention; 
         FIG. 4  is a partially cut away view of a clamp device holding a workpiece in place in accordance with an embodiment of the present invention; 
         FIG. 5  is a front view of an apparatus for mitering portions of a workpiece in accordance with an embodiment of the present invention; 
         FIG. 6A  is a top plan view of an apparatus for mitering portions of a workpiece, wherein the work surface is shown in a first position corresponding to a production stage in accordance with an embodiment of the present invention; 
         FIG. 6B  is a top plan view of the apparatus of  FIG. 6A , wherein the work surface is shown in a second position corresponding to a production stage in accordance with an embodiment of the present invention; and 
         FIG. 6C  is a top plan view of the apparatus of  FIGS. 6A and 6B , wherein the work surface is shown in a third position corresponding to a production stage in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings, and particularly to  FIG. 1 , there is illustrated an exemplary apparatus  10  for mitering portions of a workpiece in accordance with an embodiment of the present invention. In an embodiment of the present invention, a workpiece may include a portion of fabric or webbing. In another embodiment, a workpiece may include a portion of folded gusset material such as, for example, gusset material that can be used in the construction of a pillow-top mattress. In a further embodiment, a workpiece may include a portion of folded gusset material with a flange piece attached thereto. In still further embodiments, a workpiece may include a portion of folded gusset material with a portion of border material attached thereto. It will be apparent to those skilled in the art that a workpiece, as used herein, may include any combination of the above, as well as any other type of workpiece that may be mitered. 
     The exemplary apparatus  10  illustrated in  FIG. 1  includes a base assembly  12  which may, as shown in  FIG. 1 , include more than one base assembly portion  14 , 16 . In other embodiments, the apparatus  10  may include only a single base assembly. As illustrated in  FIG. 1 , for example, the apparatus  10  illustrated includes two base assembly portions  14 , 16 . The two base assembly portions  14 , 16  may be configured, as shown, to support different structures, and may be coupled to each other using any of various means known in the art. In an embodiment, one or more base assembly portions  14 , 16  may be fixably coupled by welding adjacent pieces thereof together. In another embodiment, the base assembly portions  14 , 16  may be rotatably coupled to each other, for example, to allow more convenient access to internal parts of the apparatus  10 . In still further embodiments, the base assembly portions may not be coupled to each other at all. 
     As shown in  FIG. 1 , the first base assembly portion  14  includes a pair of rear legs  18  disposed on either side of the rear side of the first base assembly portion  14  and a pair of front legs  20  similarly disposed on either side of the front side of the first base assembly portion  14 . In the illustrated embodiment, the two pairs of legs  18 , 20  are arranged in a standard rectangular design. In other embodiments, the legs may be arranged in various other designs such as for example, a triangular design. As will be appreciated by those skilled in the art, each of the base assembly portions  14 , 16  may have fewer than four legs, as the assembly portions may be coupled in such a manner as to provide adequate support with less than a full set of legs attached to each assembly portion. In other embodiments, each assembly portion may include any number of legs, arranged in any number of designs. It will be appreciated by those skilled in the art that the particular design and construction of the base assembly of a mitering apparatus is inconsequential so long as the base assembly provides appropriate support for the other elements. 
     The first base assembly portion  14 , as shown in  FIGS. 1-3 , also includes two parallel horizontal support members  22  disposed between each of the rear legs  18  and two parallel horizontal support members  24  disposed between each of the front legs  20 . The first base assembly portion  14  also includes two opposing pairs of parallel horizontal support members  26 , each pair disposed between a rear leg  18  and an adjacent front leg  20 . The first base assembly portion  14  further includes a platform  28 , as shown in  FIG. 2 , which is disposed above the topmost support members  22  and  26 . In an embodiment, the platform  28  may be attached to the support members  22 ,  26 . In other embodiments, the platform  28  may be attached to other portions of the base assembly portion  14  such as, for example, the upper portions of the legs  18 , 20 . 
     In further embodiments, the platform  28  may be rotatably coupled to the base assembly portion  14  in any manner known in the art. In still further embodiments, the base assembly portion  14  may not include platform  28 , in which case further components may be coupled directly or indirectly using other means to the base assembly  12 . In various embodiments, any number of various arrangements of support members or other construction elements may be implemented, and are intended to be within the ambit of the present invention. 
     As shown in  FIGS. 1-3 , the base assembly  12  may include a second base assembly portion  16 . The base assembly portion  16  includes a pair of rear legs  30  and a pair of opposing front legs  32  with a pair of opposing horizontal cross-members  34 , each cross-member  34  disposed between a rear leg  30  and an adjacent front leg  32 . The base assembly portion  16  also includes a pair of opposing horizontal support members  36 , which may support one or more structures, objects, or assemblies. It will be readily appreciated by those skilled in the art that the description of the base assembly herein and as illustrated in  FIG. 1  is but one embodiment of a multitude of other possible configurations, and further that the particular construction and arrangement of the base assembly is not intended to be limited by the discussions and drawings herein. Any suitable configuration of a base assembly may be used as long as it provides adequate support for the other elements of the mitering apparatus. 
     With continued reference to  FIGS. 1-3 , the apparatus  10  includes an X-Y positioning table  40  coupled to the base assembly  12 . While the designation of directions X and Y is entirely arbitrary, for the clarity of this description, the direction that runs parallel to the front edge of the apparatus  10  will be referred to as the X-direction herein, and the direction that runs perpendicular thereto (i.e., parallel to the side of the apparatus) will be referred to as the Y-direction. As illustrated in  FIGS. 1-3 , the X-Y positioning table  40  includes a work surface  41  moveably coupled to a pair of parallel rails  42  arranged along the X-direction and a pair of parallel rails  44  that are arranged along the Y-direction. The configuration of rails  42 , 44  and the moveable coupling between them and the work surface  41  allow for an X-Y positioning table  30  that can be moved in either the X-direction or the Y-direction, or in both directions. It will be appreciated to those skilled in the art that such an X-Y positioning table may be configured in any number of ways. 
     In an embodiment of the present invention, the X-Y positioning table  40  is configured so that the movement of the surface in either of the directions is achieved manually. In other embodiments such as, for example, the embodiment illustrated in  FIGS. 1-3 , the X-Y positioning table  40  may be configured so that its movement is automatic. In an embodiment, automated movement of the work surface  41  is achieved by an electric motor  46  which drives a series of belts (not shown) disposed within the rails  42 , 44 . It will be appreciated by those skilled in the art that the operation of the X-Y positioning table  40  may be automated by any number of other drive systems, as well. 
     As shown in  FIGS. 1 and 2 , the apparatus  10  includes four clamp assemblies  48  coupled to the top of the positioning table  40 . In an embodiment, the clamp assemblies  48  are fixably attached to the work surface  41  of the positioning table  40 . In other embodiments, the clamp assemblies may be attached in another manner so that they can be rotated, shifted, or moved in some other fashion. The clamp assemblies  48  may be used for holding portions of a workpiece in place on the work surface  41  of the positioning table  40 . 
     Turning to  FIG. 4 , an exemplary clamp assembly  48  is illustrated holding a portion of folded gusset material  51  in place. The clamp assembly  48  includes a top plate  52  disposed above a base plate  54 . In an embodiment, the base plate  54  may be part of the work surface of the X-Y positioning table. In another embodiment, the base plate  54  may be a separate plate attached to the work surface. In an embodiment, the top plate  52  includes a V-shaped rear edge  55  that provides a guide for a sewing head. In another embodiment, as shown in  FIG. 4 , the base plate  54  also includes such a V-shaped rear edge  56 . A lever  50  is rotatably coupled to the top plate  52  and is configured such that the clamping operation is achieved by manually applying a downward force to the lever  50 , thus securing the folded gusset material  51  between the top plate  52  and the base plate  54 . In other embodiments, the clamp assembly may be operated automatically such as, for example, by activating a motor or other system that operates the clamp. 
     In an embodiment, as illustrated in  FIGS. 1-3 , the mitering apparatus  10  includes four clamp assemblies  48 . As will be appreciated by those skilled in the art, any number of clamp assemblies  48  may be attached to the work surface  41  of the positioning table  40 . For example, as shown in  FIG. 5 , a mitering apparatus  11  is shown having two clamp assemblies  45  attached to the work surface  43 . It should be understood that a workpiece may include extra material such as, for example borders or flanges, attached thereto. In this case, it may be desirable to provide the capability of positioning portions of the workpiece adjacent the clamp assembly. It should be evident from the configuration illustrated in  FIG. 5  that the space between clamp assemblies  45  may be used in this manner. In other embodiments (not shown), a single clamp device may be attached to the positioning table. In still further embodiments, a plurality of clamp devices may be attached to the positioning table. The number of clamp devices used may depend upon the particular application for which the mitering apparatus is being used. In this regard, various embodiments of the invention may also include clamp devices that are removable, interchangeable, adjustable, and the like. 
     Returning to  FIG. 1 , the mitering apparatus  10  includes a sewing machine  58  which is coupled to the base assembly  12  and positioned adjacent the positioning table  40 . In an embodiment, the sewing machine  58  is an industrial-type sewing machine such as, for example, the Model PLK-E0504, available from Mitsubishi Electric Automation, Inc. of Grapevine, Tex. The sewing machine  58 , as illustrated in  FIGS. 1 and 2 , includes a sewing head  60  which is fed by a system of spools  62 . The sewing machine  58  is operated by a motor  64 , and is configured to sew a series of lock stitches along a V-shaped path defined by the V-shaped recessed section  56  of the clamp assembly  48 . In an embodiment, the sewing machine  58  may be configured instead to sew a series of chain stitches, and in a further embodiment, the sewing machine  58  may be configured to sew a combination of lock stitches and chain stitches. The thread used by the sewing machine  58  and fed by the system of spools  62  may include any type of thread useful for creating stitches in a workpiece. In one embodiment, for example, the thread may comprise a Kevlar thread, which is useful for creating secure stitches while maintaining fire-proof qualities. 
     With continued reference to  FIGS. 1 and 2 , the mitering apparatus  10  further includes a notching device  70  coupled to the base assembly  12  and positioned next to the sewing machine  58 . The notching device  70  is a cutting device that includes a triangular shear  72  for cutting a triangular-shaped portion out of a workpiece such as the folded gusset material  51 . In an embodiment, the triangular-shaped portion removed from the workpiece includes a portion of the workpiece adjacent the V-shaped profile of stitches created by the sewing machine  58 . The triangular shear  72  is configured to move in a downward motion through the workpiece  51 . In an embodiment, the triangular shear  72  is designed to fit within the V-shaped recessed section  56  of the clamp assembly  48 . 
     As illustrated in  FIG. 1 , the mitering apparatus includes a disposal system  76  for removing the triangular-shaped portion of the workpiece  51  from the notching device  70 . The disposal system  76  includes a hose  74  through which the removed portion of the workpiece  51  travels. The hose  74  is coupled to a vacuum pump  82  which is fixably attached to the lid  80  of a container  78 . The vacuum pump  82  is configured to create sufficient negative pressure in the hose  74  such that a removed portion of the workpiece  51  is drawn from the notching device  70  through the hose  74  and deposited in the container  78 . The container  78  may include any type of container suitable for storing removed portions of a workpiece  51 . In the embodiment illustrated in  FIG. 1 , for example, the container  78  may include a cylindrical container made of a lightweight and durable material such as plastic or rubber. In other embodiments, the container may be designed in any manner suitable for use in implementing the present invention, as will be appreciated by those skilled in the art. 
     As illustrated in  FIGS. 1 and 2 , the mitering apparatus  10  may include a controlling computer  90  which is configured for synchronizing the operation of the positioning table  40 , the sewing machine  58 , and the notching device  70 . The controlling computer  90  may include any type of computing device capable of executing computer-readable instructions. In an embodiment, the controlling computer  90  may include a computing device such as a fully-programmable personal computer (PC). In further embodiments, the controlling computer  90  may comprise a dedicated computing device specially configured for synchronizing the operation of the mitering apparatus  10 . The computing device  90  may be coupled to a display device  92  which may display any number of various types of information related to the operations of the apparatus  10 . In an embodiment, display device  92  is a touch screen device capable of receiving input from a user as well as displaying output to a user. In other embodiments, the display device  92  may be configured only for display and not include input capabilities. 
     As further illustrated in  FIGS. 1 and 2 , the mitering apparatus  10  includes a control panel  94 . The control panel  94  may be configured to receive input from a user and may include any type of input device that is configured to receive input from a user. In one example, as shown in  FIGS. 1 and 2 , the control panel  94  includes an “ON” button  95  and an “OFF” button. In other embodiments, the control panel  94  may include one or more switches or other devices for receiving user input. The “ON” button  95  illustrated here is configured to receive user input, which constitutes applying pressure to the button  95 . In response to user input received by the “ON” button  95 , the operation of the mitering apparatus  10  may be initiated. 
     As illustrated in  FIGS. 1 and 2 , the mitering apparatus includes a set of foot pedals  98 . These foot pedals  98  may be configured to provide any number of user inputs to the apparatus  10  such as for example, inputs to control the sewing machine  58 , inputs to control the positioning table  40 , and inputs to control the notching device  70 . In further embodiments, the mitering apparatus may contain only one foot pedal. In other embodiments, the mitering apparatus may contain more than two foot pedals. In still further embodiments, the mitering apparatus may not include foot pedals. 
     Additionally, as shown in  FIGS. 1 and 2 , the mitering apparatus  10  includes a guard rail  100  traversing the perimeter of the apparatus  10  and coupled to the base assembly  12 . The guard rail  100  may be configured to help keep users safe from injury such as, for example, by providing a perimeter around the apparatus  10 . It will be appreciated by those skilled in the art, however, that various embodiments of the present invention may not include a guard rail. Various other embodiments may include other types of safety features such as automatic shut-off, wall-like barriers disposed between the machine and the user (e.g. safety glass), coverings over moving parts, and the like. 
     Turning now to  FIGS. 6A-6C , an exemplary mitering apparatus  110  for automating a multiple-stage mitering process is shown. As illustrated in  FIG. 6A , the first aspect of a stage of a mitering process performed within an implementation of the present invention is shown. A stage may include any number of various operations suitable for mitering portions of a workpiece. Additionally, a multi-stage process may include any number of stages. As illustrated herein, in one embodiment, the number of stages in the process corresponds to the number of clamp devices attached to the work surface. For example, an apparatus having four clamp devices may operate in a four-stage cycle, whereas an apparatus having two clamp devices may operate in a two-stage cycle. 
     An exemplary mitering stage is illustrated in  FIGS. 6A-6C . As shown in  FIG. 6A , a first clamp device  112  is positioned adjacent to a sewing component  114  (e.g. sewing machine) such that the sewing component  114  is able to sew a series of stitches in a first secured portion of a workpiece along a V-shaped path defined by the V-shaped profile of the clamp device  112 . In an embodiment of the present invention, the V-shaped path is accomplished by first positioning a leading edge of the first clamp device  112  adjacent to the sewing component  114 . In an embodiment, the sewing component first sews a back tack, and proceeds to sew a series of stitches along the inside edge of the V-shaped profile of the first clamp device  112  as the positioning table  120  moves diagonally in the direction of the sewing component  114  and a notching component  116 , thus causing the needle of the sewing component  114  to trace the inside leading edge of the profile of the first clamp device  112 . Then, the positioning table moves diagonally away from the sewing component so as to allow the needle to trace the inside trailing edge of the profile of the first clamp device  112 . 
     As illustrated in  FIG. 4B , once the series of stitches is sewn into the secured portion of the workpiece, the first clamp device  112  is repositioned adjacent to the notching component  116 . As shown in  FIG. 4B , simultaneous to repositioning the first clamp device  112  adjacent to the notching component  116 , a second clamp device  118  is positioned adjacent to the sewing component  114 . The sewing process is repeated, with the sewing component  114  sewing a series of stitches along the inside leading edge of the second clamp device  118 . When the positioning table  120  reaches a position, as illustrated in  FIG. 4C , where the second clamp device  118  is positioned such that the needle of the sewing component  114  is positioned at the vertex  121  of the V-shaped profile of the second clamp device  118 , the first clamp device  112  is positioned directly adjacent the notching component  116 . 
     In the embodiment illustrated in  FIGS. 4A-4C , when the positioning table is in the position illustrated in  FIG. 4C , the notching component  116  cuts and removes a triangular-shaped portion from a portion of the workpiece, where the shape of the portion is defined by the V-shaped profile of the series of stitches. In an embodiment, the sewing component  114  briefly pauses in operation to allow the notching component  116  to complete its operation before the sewing component  114  begins to sew a series of stitches along the trailing edge of the second clamp device  118 . Once the sewing component  114  has completed the V-shaped series of stitches, the stage is completed. In various embodiments of the present invention, a stage may be automatically or manually repeated until each of the desired miters is created. 
     Further embodiments of the present invention are directed toward an apparatus for mitering portions of a workpiece such as a pillow-top mattress gusset, the apparatus being configured to be coupled with other components of a pillow-top mattress assembly line. Additionally, further embodiments of the present invention relate to an apparatus for mitering portions of a workpiece wherein the work surface is stationary and the sewing head and notching device are coupled to an X-Y positioning table in such a manner as to provide for a multi-stage mitering functionality similar to that described above. 
     The present invention has been described in relation to particular embodiments, which are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those of ordinary skill in the art to which the present invention pertains without departing from its scope. 
     From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects set forth above, together with other advantages which are obvious and inherent to the system and method. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.