Patent Publication Number: US-2023140513-A1

Title: Modular fixture plate system for positioning a workpiece during a manufacturing and/or inspection process

Description:
REFERENCE TO PRIOR PATENT APPLICATIONS 
     This patent application is a continuation of pending prior U.S. patent application Ser. No. 16/251,923, filed Jan. 18, 2019 by Steven E. Phillips for MODULAR FIXTURE PLATE SYSTEM FOR POSITIONING A WORKPIECE DURING A MANUFACTURING AND/OR INSPECTION PROCESS (Attorney&#39;s Docket No. PHIL-0506 CON), which patent application in turn is a continuation of prior U.S. patent application Ser. No. 14/195,607, filed Mar. 3, 2014 by Steven E. Phillips for MODULAR FIXTURE PLATE SYSTEM FOR POSITIONING A WORKPIECE DURING A MANUFACTURING AND/OR INSPECTION PROCESS (Attorney&#39;s Docket No. PHIL-0506), which in turn: 
     (i) claims benefit of prior U.S. Provisional Patent Application Ser. No. 61/771,575, filed Mar. 1, 2013 by Steven E. Phillips for LOC-N-LOAD(TM) MODULAR FIXTURE PLATE SYSTEM FOR INSPECTION MACHINES (Attorney&#39;s Docket No. PHIL-5 PROV); and 
     (ii) claims benefit of prior U.S. Provisional Patent Application Ser. No. 61/825,846, filed May 21, 2013 by Steven E. Phillips for LOC-N-LOAD™ MODULAR FIXTURE PLATE SYSTEM FOR REPEATABLE, LIGHT DUTY WORK (Attorney&#39;s Docket No. PHIL-6 PROV). 
     The four (4) above-identified patent applications are hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to methods and apparatus for manufacturing and/or inspection processes, and more particularly to methods and apparatus for positioning a workpiece during a manufacturing and/or inspection process. 
     BACKGROUND OF THE INVENTION 
     A number of manufacturing and/or inspection processes exist that require accurate, repeatable positioning of a workpiece. By way of example but not limitation, processes such as quality inspection, laser marking and etching, fiber laser and laser machining, dot peen marking, pad printing and routing all require accurate, repeatable positioning of a workpiece. 
     During a manufacturing process, a workpiece is typically held in a specific position while work is performed on the workpiece, and then the workpiece is “swapped out” for a new workpiece which is to be worked on. This new workpiece generally needs to be placed in the same, repeatable position as the preceding workpiece in order for the work process to be performed accurately. 
     In quality inspection processes, metal and/or plastic fixture plates are typically affixed to inspection machines to facilitate the quality inspection of previously-manufactured workpieces (i.e., to test the correctness of the manufactured workpieces). These fixture plates generally comprise a pattern of threaded holes formed therein which accept workpiece-holding elements such as screws, clamps, magnets, hold-downs, etc. In the quality inspection process, the previously-manufactured workpiece is placed on these metal and/or plastic fixture plates, held down with the workpiece-holding elements and then the previously-manufactured workpiece is measured for correctness. Once the workpiece on the fixture plate has been inspected, the workpiece is replaced by another workpiece which is to be inspected using the same inspection set-up, fixture plates, etc. 
     The aforementioned fixture plates are currently a one-piece design and are made to fit the workbed area of a particular inspection machine. As a result, different sizes of fixture plates must be provided for different inspection machines, thereby presenting an inventory issue or requiring long lead-times to custom manufacture fixture plates. 
     In addition to the foregoing, workpieces vary in size and, in many cases, a workpiece may be relatively small and take up only a small fraction of the complete surface area of the fixture plate provided for a given inspection machine. In this case, the remainder of the fixture plate is essentially unused during the quality inspection process. 
     In the same way that a quality inspection process applies very little force on a workpiece that is being inspected, the processes of laser marking and etching, fiber laser and laser machining, dot peen marking, pad printing, and routing also tend to apply little or no force to the workpiece. 
     In a manner similar to a quality inspection machine, these “light duty” manufacturing machines generally have a work surface on which the workpiece is supported during processing. By way of example but not limitation, the laser etching of part numbers on workpieces is a very common practice. Logo&#39;s, bar codes and/or other markings are also routinely added to workpieces. 
     For these reasons, it would be advantageous to provide a new and improved fixture plate system for positioning a workpiece during a quality inspection process and/or “light duty” manufacturing process, wherein the improved fixture plate system uses a modular approach to allow for the creation of simple but effective fixture assemblies that can provide fast, easy and repeatable setups for a specific production run. 
     SUMMARY OF THE INVENTION 
     The present invention provides a new and improved fixture plate system for positioning a workpiece during a quality inspection process and/or “light duty” manufacturing process, wherein the improved fixture plate system uses a modular approach to allow for the creation of simple but effective fixture assemblies that can provide fast, easy and repeatable setups for a specific production run. 
     In one preferred form of the invention, there is provided a modular fixture plate system comprising: 
     at least one interlocking fixture plate comprising at least one of a male end and a female end, wherein the male end comprises at least one male projection and the female end comprises at least one female recess; and a docking plate comprising at least one of at least one male projection and at least one female recess; 
     wherein at least one male projection or female recess of the at least one interlocking fixture plate is interlocked with a mating one of the at least one male projection or the at least one female recess of the docking plate. 
     In another preferred form of the invention, there is provided an interlocking fixture plate comprising: 
     a surface for receiving a workpiece; 
     a male end comprising at least one male projection; and 
     a female end comprising at least one female recess. 
     In another preferred form of the invention, there is provided a method for positioning a workpiece during a manufacturing and/or inspection process, the method comprising: 
     providing a modular fixture plate system comprising:
         at least one interlocking fixture plate comprising at least one of a male end and a female end, wherein the male end comprises at least one male projection and the female end comprises at least one female recess; and   a docking plate comprising at least one of at least one male projection and at least one female recess;       

     interlocking at least one male projection or female recess of the at least one interlocking fixture plate with a mating one of the at least one male projection or the at least one female recess of the docking plate so as to stabilize the at least one interlocking fixture plate relative to the docking plate; and 
     positioning a workpiece on the at least one interlocking fixture plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein: 
         FIGS.  1  and  2    are schematic views showing a novel modular fixture plate system formed in accordance with the present invention; 
         FIGS.  3 - 6    are schematic views showing various interlocking fixture plates formed in accordance with the present invention; 
         FIGS.  7  and  8    are schematic views showing various docking plates formed in accordance with the present invention; 
         FIG.  9    is a schematic view showing another novel modular fixture plate system formed in accordance with the present invention; 
         FIGS.  10 - 13    are schematic views showing how magnets may be mounted to interlocking fixture plates; 
         FIGS.  14 - 16    are schematic views showing how magnets may be mounted to a docking plate; 
         FIG.  17    is a schematic view showing how the novel modular fixture plate system may include a base plate; 
         FIGS.  18 - 20    show how the male projections and female recesses of the interlocking fixture plates and the docking plate may be formed with a dovetail configuration; 
         FIG.  21    is a schematic view showing how the interface of a male projection and a female recess may be given a unique “Location” or “LOC” number; 
         FIGS.  22 - 27    are schematic views showing how the novel modular fixture plate system may include a removable qualifying ball plate; 
         FIGS.  28 - 31    are schematic views showing how the various elements of the novel modular fixture plate system may be formed out of molded plastic; 
         FIGS.  32  and  33    are schematic views showing how an interlocking fixture plate may be formed out of a conventional fixture plate and an “add on” male projection. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention provides a new and improved fixture plate system for positioning a workpiece during a quality inspection process and/or “light duty” manufacturing process, wherein the improved fixture plate system uses a modular approach to allow for the creation of simple but effective fixture assemblies that can provide fast, easy and repeatable setups for a specific production run. 
     Among other things, the present invention comprises a new modular fixture plate system which allows for, and encourages, lean manufacturing principles for, but not limited to, quality inspection processes and “light duty” manufacturing processes such as laser marking and etching, fiber laser and laser machining, dot peen marking, pad printing and routing processes. More particularly, the present invention comprises a modular fixture plate system which comprises a plurality of interlocking plates which are selected, and then assembled together, so as to form a complete fixture plate, or which can be used individually so as to allow a portion of the workbed area of the inspection or manufacturing machine to be exposed, with the specific interlocking plates used being selected according to the size of the workpiece which is to be held, so that only those interlocking plates are used which are required to hold the workpiece of interest. Or, in another aspect of the present invention, a workpiece may be set up and programmed for inspection or working on a single interlocking plate, which can then be easily positioned on the inspection or manufacturing machine, the workpiece inspected or worked, then the workpiece and interlocking plate may be removed as a unit from the workbed of the inspection or manufacturing machine and thereafter be replaced by another workpiece and interlocking plate. The new modular fixture plate system of the present invention encourages inspectors and machine operators to employ lean manufacturing principles in the inspection and “light duty” manufacturing processes, using the minimum resources required, and enhances the value and investment of the inspection and “light duty” manufacturing equipment. 
     Looking first at  FIGS.  1  and  2   , there is shown a new modular fixture plate system  5  formed in accordance with the present invention. Modular plate system  5  generally comprises one or more interlocking fixture plates  10  which are intended to be positioned on the workbed  12  of an inspection or “light duty” manufacturing machine. Each interlocking fixture plate  10  comprises a male end  15  and a female end  20 , wherein male end  15  comprises at least one male projection  25  and female end  20  comprises at least one female recess  30 . Preferably interlocking fixture plates  10  comprise a plurality of threaded holes  32 , preferably disposed in a regular pattern, for accepting workpiece-holding elements well known in the art, e.g., screws, clamps, magnets, hold-downs, etc. As seen in  FIGS.  1 - 6    interlocking fixture plates  10  can be formed in a variety of configurations, each with one or more male projections  25  and one or more female recesses  30 . 
     Modular plate system  5  also comprises a docking plate  35  ( FIGS.  1 ,  2 ,  7  and  8   ) which is intended to be affixed to the workbed of the inspection or “light duty” manufacturing machine, e.g., using an adhesive in which case the docking plate may comprise a solid structure ( FIGS.  1  and  2   ) or using bolts which extend through counterbored slots  40  formed in docking plate  35  ( FIGS.  7  and  8   ). Docking plate  35  comprises a plurality of female recesses  30  ( FIGS.  1 ,  2 ,  7  and  8   ), also sometimes referred to herein as “Locations” or “LOCs”, which receive male projections  25  of one or more interlocking fixture plates  10  or, alternatively, docking plate  35  comprises a plurality of male projections  25  for projecting into female recesses  30  of one or more interlocking fixture plates  10  ( FIG.  9   ). 
     Docking plate  35  and the various interlocking fixture plates  10  are designed to fit tightly together in an interlocked manner, with a male projection  25  of one element being received in a female recess  30  of another element. By way of example but not limitation, where docking plate  35  comprises a plurality of female recesses  30  ( FIGS.  1 ,  2  and  9   ), a plurality of interlocking fixture plates  10  may be interlocked with docking plate  35 , and also with one another, by projecting the male projections  25  of some of the interlocking fixture plates  10  into the female recesses  30  of docking plate  35  and by projecting the male projections  25  of others of the interlocking fixture plates  10  into the female recesses  30  of the interlocking fixture plates  10  interlocked with docking plate  35 . By way of further example but not limitation, a docking plate  35  having a plurality of male projections  25  may be interlocked with interlocking fixture plates  10  by projecting the male projections of docking plate  35  into the female recesses of interlocking fixture plates  10  ( FIG.  9   ). 
     Thus it will be seen that with fixture plate system  5 , a plurality of interlocking fixture plates  10  can be interlocked with one another, and with docking plate  35 , so as to cover some or all of the workbed of an inspection or manufacturing machine, and a large workpiece can span a number of interlocked fixture plates  10 . In other words, with the present invention, interlocking fixture plates  10  fit together (e.g., in the manner of a jigsaw puzzle) to collectively create the desired overall size for the fixture plate. 
     Preferably docking plate  35  and the various interlocking fixture plates  10  are further secured to one another by magnets  45  which are disposed adjacent to male projections  25  of interlocking fixture plates  10  ( FIGS.  10  and  11   ) and adjacent to female recesses  30  of interlocking fixture plates  10  ( FIGS.  12  and  13   ), and by magnets  45  which are disposed adjacent to female recesses  30  of docking plate  35  ( FIG.  14   ) and adjacent to male projections  25  of docking plate  35  ( FIGS.  15  and  16   ). Preferably magnets  45  are inset into docking plate  35  and interlocking fixture plates  10  so that the magnets of one plate mate with the magnets of an adjoining plate when a male projection  25  is received in a female recess  30 . Using magnets  45  to secure docking plate  35  and interlocking fixture plates  10  to one another allow interlocking fixture plates  10  to be easily released from one another, and from docking plate  35 , by hand and without the use of tools, whereby to enable interlocking fixture plates  10  to be quickly and easily swapped out as needed. 
     Alternatively, if desired, other means (e.g., a spring plunger set screw) may be used to secure docking plate  35  and the various interlocking fixture plates  10  to one another. 
     Or, if desired, two or more docking plates  35  may be used in opposing arrangement ( FIG.  9   ) so as to lock the interlocking fixture plates  10  in position. 
     Since many “light duty” manufacturing machines (e.g., laser engraving machines and the like) are not necessarily sold with a workbed surface, modular fixture plate system  5  may also comprise a base plate  50  ( FIG.  17   ) on which the remainder of the system (e.g., docking plate  35  and one or more interlocking fixture plates  10 ) may be mounted. 
     For some “light duty” manufacturing machines (e.g., workpiece marking machines), one preferred form of the invention may provide an interlocking fixture plate  10  which interlocks with only docking plate  35  ( FIG.  17   ), with the opposite end of interlocking fixture plate  10  being straight and with or without a handle or finger grip for easier removal of interlocking fixture plate  10 . 
     Alternatively, modular plate system  5  may provide docking plates  35  on all sides of interlocking fixture plates  10  so that the interlocking fixture plates  10  are interlocked, much like the pieces of a puzzle. In this case, the aforementioned magnets  45  can be omitted. 
     In still another form of the present invention, male projections  25  and female recesses  30  may utilize a dovetail configuration ( FIGS.  18 - 20   ). 
     It should be appreciated that each of the interlocks of an interlocking fixture plate  10  with a docking plate  35  (i.e., a male projection  25  fitting into a female recess  30 ) can be assigned a “Location” or “LOC” number (see  FIGS.  2 ,  7 ,  9 ,  20  and  21   ). Inspection and manufacturing programs can be written and assigned to a specific “Location” or “LOC” number, i.e., to a specific location of an interlocking fixture plate  10  relative to docking plate  35 . Programming inspection and manufacturing setups based on the interlocking fixture plate location or assignment allows for faster repeat setups and allows for more than one setup per machine (i.e., it permits work to be effected at LOC 1 , LOC 2 , LOC 3 , etc.), thereby speeding up the inspection and manufacturing processes. 
     The hole pattern (i.e., the pattern of the holes  32  provided in interlocking fixture plates  10 ) is preferably consistent and seamless across all interlocking fixture plates  10  ( FIGS.  1  and  2   ). By way of example but not limitation, a ¼−20 or M 6  Threaded hole pattern with 1 inch spacing is shown in  FIGS.  1  and  2   . The described thread and hole pattern is typical of the industry, however, it can vary widely in thread size and hole spacing without departing from the scope of the present invention. In one form of the present invention, interlocking fixture plates  10  can be created as “blanks” (i.e., without holes  32 ) so that the end user can then add the holes  32  in the sizes and/or patterns desired. 
     Another unique feature of modular fixture plate system  5  is the provision of a removable qualifying ball plate  55  which may be used for quality inspection, e.g.,  FIGS.  22  and  23    show one possible configuration for qualifying ball plate  55  and FIGS.  24  and  25  show another possible configuration for qualifying ball plate  55 . The removable qualifying ball plate  55  preferably comprises a rounded end  60  on one end and a male projection  25  on its other end, where male projection  25  allows removable qualifying ball plate  55  to be secured to another element of modular fixture plate system  5  (i.e., an interlocking fixture plate  10  or a docking plate  35 ). Alternatively, removable qualifying ball plate  55  may comprise a rounded end  60  on one end and a female recess  30  on its other end, where female recess  30  allows removable qualifying ball plate  55  to be secured to another element of modular fixture plate system  5  (i.e., an interlocking fixture plate  10  or a docking plate  35 ). The removable qualifying ball plate  55  is a precise tool which carries a qualifying ball  62  ( FIGS.  26  and  27   ) which the probe of an inspection machine touches in order to register the inspection machine. By way of example but not limitation, qualifying ball  62  can be attached to removable qualifying ball plate  55  (e.g., to rounded end  60  of removable qualifying ball plate  55 ) such that qualifying ball  62  is upstanding from the plane of removable qualifying ball plate  55 . This removable qualifying ball plate  55  will normally stay on the inspection machine&#39;s work surface while manufactured workpieces are inspected. This removable qualifying ball plate  55  is designed to accept the qualifying ball  62  (or the inspection machine test bar), provide an accurate surface for indicating with respect to the inspection machine probe, and can be moved out of the way quickly and easily when not in use. The surface area and work envelope of the inspection machine is completely free from obstructions and then has more useable space. 
     The suggested material of all interlocking fixture plates  10  is half inch thick aluminum plate, however, the interlocking fixture plates can be manufactured in a variety of other metals or plastics (see  FIGS.  28 - 31   ) and can vary in thickness, overall size and geometry, with threaded, straight or tapered holes  32 , with and without a subplate. The size of the interlocking fixture plates  10  is chosen based on the size and number of workpieces, and for the size of the machine work area. 
       FIGS.  32  and  33    show another possible construction for interlocking fixture plates  10 , wherein male projection  25  is manufactured separately from the remainder of interlocking fixture plate  10 , and is added during the manufacturing process. This approach has the advantage that male projection  25  can be added to an existing fixture plate so as to make it usable with the present invention. 
     Benefits of the New Fixture Plate System 
     Some of the benefits of the new modular fixture plate system  5  are as follows:
         The continuous threaded hole pattern from one interlocking fixture plate to another creates a seamless surface when the interlocking fixture plates  10  are assembled together.   The interlocking fixture plates  10  can be swapped out quickly while maintaining an accurate repeatable location.   The interlocking fixture plates  10  can be ordered as blanks (i.e., without holes) and then customized by the end user for an even lower cost solution.   Standard-sized interlocking fixture plates  10  can be ordered “off-the-shelf”, and then configured quickly according to the end user&#39;s particular work needs.   Initial costs are lower since the end user need only order the docking plate  35  and those interlocking fixture plates  10  needed for a particular job, and the end user can then add additional interlocking fixture plates  10  anytime thereafter as needed.   No tools are necessary to assembly/disassemble particular setups of the modular fixture plate system (after docking plate  35  has been secured to the workbed of a machine).   Docking plate  35  can be mounted to the workbed of the inspection or manufacturing machine using either an adhesive (e.g., double-sided tape) or bolts, etc.   Interlocking fixture plates  10  are provided in various sizes so as to collectively make up a uniform, larger fixture plate assembly.   Multiple workpieces can be fixed to an interlocking fixture plate  10  and then that interlocking fixture plate  10  can be “swapped out” for inspecting and/or working all of the workpieces at the same time; the interlocking fixture plates  10  can be stored when the job is complete.   Interlocking fixture plates  10  can be provided with dedicated tooling for jobs to reduce setup times and machine operators can pre-set workpieces on interlocking fixture plates  10  so that the workpieces are ready to be inspected and/or worked, thereby improving the production process.   Multiple interlocking fixture plates  10  can be provided to accommodate larger workpieces.   It is not necessary to cover the entire workbed with interlocking fixture plates  10 .   The ends of the interlocking fixture plates  10  interlock with one another, and may be kept in place using magnets (e.g., strong rare earth magnets) for a strong locking action.   Docking plate  35  seats against a far side of a machine&#39;s workbed (i.e., out of the way of the work envelope/travel of the probe, laser, or other tools) whereby to provide maximum use of the machine&#39;s workbed.   Docking plate  35  can be quickly and easily secured to the workbed by using double-sided tape or by using counterbored slots  40  to bolt the docking plate to the machine workbed.   Interlocking fixture plates  10  can be provided in various sizes, whereby to fit any size machine workbed or to accommodate any size workpiece requiring inspection, marking, or light machining.   Designed to reflect Lean Manufacturing principles.   Interlocking fixture plates  10  can be quickly “swapped out” for inspection, thereby reducing the chance of damaging probes.   Existing interlocking fixture plates  10  can be retroactively modified for use with the system using separately-manufactured male projections  25 .   A special ball plate  55  can be provided for quality inspection (i.e., locating the ball). The ball can be inspected and then moved out of the way quickly for an unobstructed workbed.   A simple and inexpensive base plate  50  can be provided to mount the fixture plate system  5  to a machine.   Plastic injection molding can be used to manufacture low-cost interlocking fixture plates  10  for the marking industry.       

     Modifications of the Preferred Embodiments 
     It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.