Patent Publication Number: US-2022234148-A1

Title: Workpiece positioner assembly having compliance assemblies

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to U.S. Provisional Application No. 63/142,651, filed on Jan. 28, 2021, the entire contents of which are herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a workpiece manipulator or positioner. The positioner may be utilized to position successive workpieces relative to industrial robot(s) for processing by the robot(s), or a tool(s) held by the robot(s). 
     Discussion of the Background 
     Industries often employ industrial robots for a variety of applications in the course of manufacturing. While many industrial robot arms are able to function on several rotational axes, manufacturing efficiency can be improved by employing a manipulator or positioner in cooperation with the robot arm. The positioner can be utilized to position an otherwise static series of workpieces relative to the industrial robot such that the workpieces, one after the other, may be processed. The positioner also helps optimize the process and throughput. 
     However, when using a positioner in a fixed headstock/tailstock configuration, the centerlines of the headstock and tailstock faceplates typically need to be in proper alignment. Misalignment can create headstock bearing loads and rotational drag, stalling and/or premature failure causing damage to the drive assembly and, therefore, increasing costs. Other problems caused by misalignment of the assembly include shearing of the tooling from the positioner and/or distortion of the workpiece. 
     The present inventors have recognized a need for improvements in the robotic headstock/tailstock positioner design. 
     SUMMARY OF THE INVENTION 
     The present invention advantageously provides a workpiece positioner assembly including a headstock apparatus having a motor and a headstock swing arm rotatably supported on the headstock apparatus. The headstock swing arm is configured to be rotated by the motor. The workpiece positioner assembly further includes a tailstock apparatus and a tailstock swing arm rotatably supported on the tailstock apparatus. The tailstock swing arm and the headstock swing arm are configured to support a workpiece. The workpiece positioner assembly also includes a beam coupled to the headstock swing arm and to the tailstock swing arm to transmit rotation of the headstock swing arm to the tailstock swing arm, and a compliance assembly. The compliance assembly is provided between at least one of the headstock swing arm and the beam to enable relative movement between the headstock swing arm and the beam, and the tailstock swing arm and the beam to enable relative movement between the tailstock swing arm and the beam. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the invention and many of the attendant advantages thereof will become readily apparent with reference to the following detailed description, particularly when considered in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a top, front, left perspective view of a workpiece positioner assembly according to an embodiment of the present invention; 
         FIG. 2  is a front view of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 3  is a top view of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 4A  is a left side view of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 4B  is a right side view of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 5  is a top, front, left perspective view of a tailstock apparatus and a compliance assembly of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 6  is a top view of the tailstock apparatus and the compliance assembly of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 7  is a left side view of the tailstock apparatus and the compliance assembly of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 8  is a partial cross-section view of the tailstock apparatus and the compliance assembly taken along line VIII-VIII in  FIG. 7 ; 
         FIG. 9  is a top, front, left perspective, partially-exploded view of the tailstock apparatus and the compliance assembly of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 10  is a top, front, right perspective view of a headstock apparatus and a compliance assembly of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 11  is a top view of the headstock apparatus and the compliance assembly of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 12  is a right side view of the headstock apparatus and the compliance assembly of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 13  is a partial cross-section view and partial schematic view of a drive assembly of the headstock apparatus and the compliance assembly taken along line XIII-XIII in  FIG. 12 ; 
         FIG. 14  is a top, front, left perspective, partially-exploded view of the headstock apparatus and the compliance assembly of the workpiece positioner assembly of  FIG. 1 ; 
         FIG. 15  is a top, front, right perspective view of a compliance assembly according to an embodiment of the present invention; 
         FIG. 16  is a bottom, rear, left perspective view of the compliance assembly of  FIG. 15 ; 
         FIG. 17A  is a front view of the compliance assembly of  FIG. 15 ; 
         FIG. 17B  is a top view of the compliance assembly of  FIG. 15 ; 
         FIG. 17C  is a cross-sectional view of the compliance assembly taken along lines XVII C-XVII C in  FIG. 17A ; 
         FIG. 17D  is a cross-sectional view of the compliance assembly taken along line XVII D-XVII D in  FIG. 17A ; 
         FIG. 18  is a top, rear, left, partially-exploded perspective view of the compliance assembly of  FIG. 15 ; and 
         FIG. 19  illustrates an embodiment of a computer with which the workpiece positioner assembly according to an embodiment of the invention may be implemented. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION 
     Embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. In the following description, the constituent elements having substantially the same function and arrangement are denoted by the same reference numerals, and repetitive descriptions will be made only when necessary. 
     The present invention relates to headstock/tailstock positioners and, more particularly, to a flexible interface for headstock/tailstock positioners that can be employed in combination with industrial robot(s). 
     A workpiece positioner assembly  100  comprises a headstock apparatus  200  that is configured to rotate a workpiece in conjunction with a tailstock apparatus  600 . The headstock apparatus  200  (see, e.g.,  FIGS. 1-4B and 10-14 ) includes a headstock swing arm  210  and a base (or pedestal)  250 . The headstock swing arm  210  supports a first headstock workpiece mounting module  220  and a second headstock workpiece mounting module  240 . The headstock swing arm  210  is rotatably supported on the base  250  of the headstock apparatus  200 . The tailstock apparatus  600  (see, e.g.,  FIGS. 1-9 ) includes a tailstock swing arm  610  and a base (or pedestal)  650 . The tailstock swing arm  610  supports a first tailstock workpiece mounting module  620  and a second tailstock workpiece mounting module  640 . The tailstock swing arm  610  is rotatably supported on the base  650  of the tailstock apparatus  600 . 
     The workpiece positioner assembly  100  of the present embodiment further comprises a headstock compliance assembly (or first compliance assembly)  300 , a center beam (or beam)  400 , and a tailstock compliance assembly (or second compliance assembly)  500 . The headstock compliance assembly  300  is provided between the headstock swing arm  210  and the beam  400  to enable relative movement between the headstock swing arm  210  and the beam  400 . The tailstock compliance assembly  500  is provided between the tailstock swing arm  610  and the beam  400  to enable relative movement between the tailstock swing arm  610  and the beam  400 . 
     The headstock compliance assembly  300 , which enables pitch and yaw and axial movement relative to the headstock swing arm  210 , is installed between the swing arm  210  and the center beam  400 . The center beam  400  is attached to the tailstock compliance assembly  500 , again enabling pitch and yaw movement relative to a tailstock swing arm  610 . The tailstock swing arm  610  is rotatably supported on the base  650  of a tailstock apparatus  600 . Compliance assemblies  300 ,  500  used in this manner allow the center beam  400  to be primarily a torque transmission component and not a vertical load or moment supporting member, this is true for all lengths of center beams. 
     The headstock apparatus  200  includes an electrically powered drive assembly (or headstock positioner)(shown in  FIG. 13 ), which is configured to “position” or rotate the otherwise static workpiece, in cooperation with the tailstock apparatus  600 , relative to one or more industrial robotic arms for more effective processing of workpieces during manufacturing. Thus, the device comprising the workpiece positioner assembly  100  can further comprise one or more industrial robots RB. The center beam  400  transmits rotation of the headstock swing arm  200 , which is driven by a drive assembly of the headstock apparatus  200 , to the tailstock swing arm  610 , which is rotatably supported by the tailstock apparatus  600 . 
     The center beam  400  also acts as a shield to separate a robot side  104  (or more generally workpiece processing (e.g., welding) side) of the workpiece positioner assembly  100  from an operator side  102 . (See, e.g.,  FIG. 3, 4A, 4B , etc.) An operator stands OP on the operator side  102  to load a workpiece or workpieces between a first headstock workpiece mounting module  220  and a first tailstock workpiece mounting module  620 , when in the orientation shown in  FIGS. 1 and 3 . The workpiece W 1  can extend from the first headstock workpiece mounting module  220  to the first tailstock workpiece mounting module  620 , or the workpiece(s) can be mounted to a workpiece mount that extends from the first headstock workpiece mounting module  220  to the first tailstock workpiece mounting module  620 . The operator OP can then control the workpiece positioner assembly  100  such that the headstock swing arm  210 , the center beam  400 , and the tailstock swing arm  610  rotate in a rotational direction R such that the first headstock workpiece mounting module  220  and the first tailstock workpiece mounting module  620  move from their positions shown in  FIG. 1  on the operator side  102  to the positions of a second headstock workpiece mounting module  240  and a second tailstock workpiece mounting module  640  shown in  FIG. 1  on the robot side  104 . Thus, due to this rotation, the first headstock workpiece mounting module  220  and the first tailstock workpiece mounting module  620  move from the operator side  102  to the robot side  104 , so that the robot(s) RB on the robot side  104  can work on the workpiece(s) W 1 . This rotation conversely moves the second headstock workpiece mounting module  240  and the second tailstock workpiece mounting module  640  from the robot side  104  to the operator side  102 , so that the operator can unload any workpiece(s) W 2  on the second headstock workpiece mounting module  240  and the second tailstock workpiece mounting module  640  and load any new workpiece(s) thereon. After the robot(s) RB has completed the work on the workpiece(s) W 1  on the first headstock workpiece mounting module  220  and the first tailstock workpiece mounting module  620 , and after the operator OP has completed unloading/loading of workpiece(s) W 2  on the second headstock workpiece mounting module  240  and the second tailstock workpiece mounting module  640 , then the operator OP can control the workpiece positioner assembly  100  such that the headstock swing arm  210 , the center beam  400 , and the tailstock swing arm  610  rotate in the rotational direction R either in the same rotational direction as during the previous rotation (e.g., +R direction, if previous rotation was +R direction) or in an opposite rotational direction (e.g., −R direction, if previous rotation was +R direction). (See, e.g., U.S. Pat. Nos. 6,281,474 and 7,434,491, which are incorporated herein in their entirety, for additional background/reference information.) 
     It is noted that the first headstock workpiece mounting module  220  and the first tailstock workpiece mounting module  620  can rotate in a rotational direction R 1  in order to position the workpiece(s) W 1  supported thereon in order to facilitate load, work processing, and unloading of the workpiece(s) W 1 . It is further noted that the second headstock workpiece mounting module  240  and the second tailstock workpiece mounting module  640  can rotate in a rotational direction R 2  in order to position the workpiece(s) W 2  supported thereon in order to facilitate load, work processing, and unloading of the workpiece(s) W 2 . 
     The center beam  400  is configured as a shield to separate a first area  402  between the first headstock workpiece mounting module  220  and the first tailstock workpiece mounting module  620  from a second area  404  between the second headstock workpiece mounting module  240  and the second tailstock workpiece mounting module  640 . (See, e.g.,  FIG. 3 .) As the headstock swing arm  200 , the center beam  400 , and the tailstock apparatus  600  rotate together, the first area  402  and the second area  404  can be rotated between the operator side  102  at which workpieces are loaded and unloaded (and/or worked by an operator) and the robot side  104  at which a robot works the workpieces. The workpiece(s) W 1  are supported between the first headstock workpiece mounting module  220  and the first tailstock workpiece mounting module  620  in the first area  402 , and the workpiece(s) W 2  are supported between the second headstock workpiece mounting module  240  and the second tailstock workpiece mounting module  640  in the second area  404 , as shown in  FIG. 3 . 
     The headstock swing arm  210  has a first axis of rotation A 1  as rotatably supported by the headstock apparatus  200 . The first axis of rotation A 1  extends along the Z axis. The tailstock swing arm  610  has a second axis of rotation A 2  as rotatably supported by the tailstock apparatus  600 . However, the headstock apparatus  200  (e.g., at a bottom of base or pedestal  250 ) and the tailstock apparatus  600  (e.g., at a bottom of base or pedestal  650 ) is be mounted to a floor FL such that the first axis of rotation A 1  is not precisely aligned with the second axis of rotation A 2  (e.g., the first axis of rotation and second axis of rotation are parallel but offset from one another, or the first axis of rotation and second axis of rotation are at an angle with respect to one another (i.e. not parallel)). Thus, the center beam  400  has a third axis (or longitudinal axis) A 3  that is not aligned with one or both of the first axis of rotation A 1  and the second axis of rotation A 2 . The first compliance assembly  300  and the second compliance assembly  500  allow for the center beam  400  to be used to transmit torque from the headstock apparatus  200  to the tailstock apparatus  600  with such misaligned axes of rotation by providing a first flexible coupling via the first compliance assembly  300  between the headstock swing arm  210  (or the driving shaft of the headstock apparatus  200  rotating the headstock swing arm  210 ) and the center beam  400  and a second flexible coupling via the second compliance assembly  500  between the center beam  400  and the tailstock swing arm  610  (or the supporting (or driven)) shaft of the tailstock apparatus  600  rotating the tailstock swing arm  610 ). 
     Thus, the first compliance assembly  300  is provided between the headstock swing arm  210  and the beam  400  to enable relative movement including flexing pitch movement (i.e. rotation about Y axis as seen in  FIG. 1 ), flexing yaw movement (i.e., rotation about X axis as seen in  FIG. 1 ), and flexing axial movements (i.e., translation along Z axis as seen in  FIG. 1 ) relative to the first axis of rotation A 1  of the headstock swing arm  210 , and the second compliance assembly  500  is provided between the tailstock swing arm  610  and the beam  400  to enable relative movement including flexing pitch movement (i.e. rotation about Y axis as seen in  FIG. 1 ), flexing yaw movement (i.e., rotation about X axis as seen in  FIG. 1 ), and flexing axial movements (i.e., translation along Z axis as seen in  FIG. 1 ) relative to the second axis of rotation A 2  of the tailstock swing arm  610 . The compliance assembly  300  provides stiff torque transmission from the headstock swing arm  210  to the tailstock swing arm  610  via the beam  400  by enabling relative movement between the longitudinal axis A 3  and the first axis of rotation A 1 . The compliance assembly  500  provides stiff torque transmission from the headstock swing arm  210  to the tailstock swing arm  610  via the beam  400  by enabling relative movement between the longitudinal axis A 3  and the second axis of rotation A 2 . 
     The headstock apparatus  200  includes a drive assembly as shown in  FIGS. 13 and 14 . The headstock apparatus  200  has a motor  260  having an output shaft  262 , as seen in  FIGS. 13 and 14 . The output shaft  262  drives an input gear assembly  264  that include bevel, spur, and helical gears. The output of input gear assembly  264  rotates the input of a first axis reduction assembly  266  which in turn drives the first axis of rotation A 1 . The motor  260  drives the headstock swing arm  210  about the first axis of rotation using the output shaft  262 , the input gear assembly  264 , and the first axis reduction assembly  266 . The headstock swing arm  210  is mounted to the first axis reduction assembly  266  by screws  202 , as can be seen in  FIGS. 13 and 14 . 
     As shown, for example, in  FIGS. 8 and 9 , the tailstock swing arm  610  is mounted to an adapter plate  602  by screws  612 , and the adapter plate  602  is mounted to a rotational bearing  660  by screws  604 . The rotational bearing  660  is mounted to and supported by base or pedestal  650  of the tailstock apparatus  600 . 
     The workpiece positioner assembly  100  including the compliance assemblies  300 ,  500  are advantageously used in low speed cycling applications. For example, low speed cycling applications in which the center beam  400  is rotated at low rotational speeds of less than or equal to 50 revolutions per minute. 
       FIGS. 15-18  depict an embodiment of a compliance assembly that corresponds to both the first compliance assembly  300  and the second compliance assembly  500 . In the present embodiment, as both the first and second compliance assemblies  300 ,  500  have the same structures,  FIGS. 15-18  depict an embodiment of both the first and second compliance assemblies  300 ,  500  with corresponding reference numerals for each assembly shown in these figures. 
     The first compliance assembly  300  includes a first beam-side coupling plate  320  rigidly connected to the beam  400  (as shown in  FIGS. 1 and 3 ), a headstock apparatus-side coupling plate  360  rigidly connected to the headstock swing arm  210 , and a first flexible coupling member  340 . The first flexible coupling member  340  is coupled to the first beam-side coupling plate  320 . The first flexible coupling member  340  is also coupled to the headstock apparatus-side coupling plate  360 . 
     The first flexible coupling member  340  has an annular shape, as can be seen in  FIG. 18 . The first flexible coupling member  340  has a planar shape when viewed in a direction perpendicular to the first axis of rotation A 1 , as can be seen, for example, in  FIGS. 10, 11, 17C, 17D, and 18 . 
     The first compliance assembly  300  further includes first rod members  350  circumferentially provided about the annular shape of the first flexible coupling member  340 . In this embodiment, the first rod members  350  are bolts; however, other types of rod members and fasteners can be used. The first rod members  350  connect the first flexible coupling member  340  to the first beam-side coupling plate  320 . The first compliance assembly  300  further includes second rod members  344  circumferentially provided about the annular shape of the first flexible coupling member  340 . In this embodiment, the second rod members  344  are bolts; however, other types of rod members and fasteners can be used. The second rod members  344  connect the first flexible coupling member  340  to the headstock apparatus-side coupling plate  360 . The first rod members  350  and the second rod members  344  are alternately provided about a circumference of the annular shape of the first flexible coupling member  340 . The first rod members  350  and the second rod members  344  are evenly spaced from each other about the circumference of the annular shape of the first flexible coupling member  340 . 
     The planar shape of the first flexible coupling member  340  allows for bending and flexing of the first flexible coupling member  340  when acted upon by forces transmitted from the first beam-side coupling plate  320  by one or more of the first rod members  350  and forces transmitted from the headstock apparatus-side coupling plate  360  by one or more of the second rod members  344 . 
     The second compliance assembly  500  includes a second beam-side coupling plate  520  rigidly connected to the beam  400  (as shown in  FIGS. 1 and 3 ), a tailstock apparatus-side coupling plate  560  rigidly connected to the tailstock swing arm  610 , and a second flexible coupling member  540 . The second flexible coupling member  540  is coupled to the second beam-side coupling plate  520 . The second flexible coupling member  540  is coupled to the tailstock apparatus-side coupling plate  560 . 
     The second flexible coupling member  540  has an annular shape, as can be seen in  FIG. 18 . The second flexible coupling member  540  has a planar shape when viewed in a direction perpendicular to the first axis of rotation A 1 , as can be seen, for example, in  FIGS. 5, 6, 17C, 17D, and 18 . 
     The second compliance assembly  500  further includes third rod members  550  circumferentially provided about the annular shape of the second flexible coupling member  540 . In this embodiment, the third rod members  550  are bolts; however, other types of rod members and fasteners can be used. The third rod members  550  connect the second flexible coupling member  540  to the second beam-side coupling plate  520 . The second compliance assembly  500  further includes fourth rod members  544  circumferentially provided about the annular shape of the second flexible coupling member  540 . In this embodiment, the fourth rod members  544  are bolts; however, other types of rod members and fasteners can be used. The fourth rod members  544  connect the second flexible coupling member  540  to the tailstock apparatus-side coupling plate  560 . The third rod members  550  and the fourth rod members  544  are alternately provided about a circumference of the annular shape of the second flexible coupling member  540 . The third rod members  550  and the fourth rod members  544  are evenly spaced from each other about the circumference of the annular shape of the second flexible coupling member  540 . 
     The planar shape of the second flexible coupling member  540  allows for bending and flexing of the second flexible coupling member  540  when acted upon by forces transmitted from the second beam-side coupling plate  520  by one or more of the third rod members  550  and forces transmitted from the tailstock apparatus-side coupling plate  560  by one or more of the fourth rod members  544 . 
     The center beam  400  has mounting plates  410 A,  410 B on ends thereof, as can be seen in  FIGS. 1-3 . Holes  322  in the beam-side plate  320  allow screws  420 A to extend through the mounting plate  410 A of the center beam  400  and into holes  322  to join beam-side plate  320  to a first end of the center beam  400 . Holes  522  allow screws  420 B to extend through the mounting plate  410 B of the center beam  400  and into holes  522  to join beam-side plate  520  to a second end of the center beam  400 . 
     Holes  324  in beam-side plate  320  allow screws  310  (see, e.g.,  FIGS. 13 and 14 ) to extend therethrough (the screws  310  sitting within but not joining to holes  324 ) and to extend through holes  368  in headstock apparatus-side coupling plate  360  to join plate  360  to the headstock apparatus  200  via holes  368 . Holes  524  in beam-side plate  520  allow screws  510  (see, e.g.,  FIGS. 8 and 9 ) to extend therethrough (the screws  510  sitting within but not joining to holes  524 ) and to extend through holes  568  in tailstock apparatus-side coupling plate  560  to join plate  560  to the tailstock apparatus  600  via holes  568 . 
     Screws  326 ,  526  extend through holes  328 ,  528  in the four corners of beam-side plates  320 ,  520  and extend into and threadedly engage with holes  362 ,  562  in headstock apparatus-side plate  360 , tailstock apparatus-side plate  560 , respectively. The screws  326 ,  526  are used for assembly and then the screws  326 ,  526  are used for compressing the compliance assemblies  300 ,  500  to prevent damage during shipping. The screws  326 ,  526  are removed for normal operation. 
     The flexible coupling member  340  has four circumferentially evenly spaced holes  342  and four circumferentially evenly spaced holes  352 . The flexible coupling member  540  has four circumferentially evenly spaced holes  542  and four circumferentially evenly spaced holes  552 . 
     Four evenly spaced bolts  344 ,  544  (please note that for simplicity of drawings three of these bolts are shown on the members  340 ,  540  in  FIG. 18 , but would instead be mounted in the same manner as the labeled bolt  344 ,  544  in  FIG. 18 ) extend through four evenly spaced holes  364 ,  564  in plates  360 ,  560 , and through holes  342 ,  542  in members  340 ,  540 , and into enlarged four evenly spaced holes  330 ,  530  in plates  320 ,  520 . Nuts  346 ,  546  are threadedly engaged to bolts  344 ,  544  to join plates  360 ,  560  to members  340 ,  540 . The nuts  346 ,  546  and the ends of bolts  344 ,  544  sit within but do not join to enlarged holes  330 ,  530 . 
     Four evenly spaced bolts  350 ,  550  (please note that for simplicity of drawings three of these bolts are shown on the members  340 ,  540  in  FIG. 18 , but would instead be mounted in the same manner as the labeled bolt  350 ,  550  in  FIG. 18 ) extend through holes  332 ,  532  in plates  320 ,  520 , and through holes  352 ,  552  in members  340 ,  540 , and into enlarged holes  366 ,  566  in plates  360 ,  560 . Nuts  366 ,  566  are threadedly engaged to bolts  350 ,  550  to join plates  320 ,  520  to members  340 ,  540 . The nuts  356 ,  556  and the ends of bolts  350 ,  550  sit within but do not join to enlarged holes  366 ,  566 . 
     Thus, the headstock apparatus-side coupling plate  360  provides a rigid connection between the headstock swing arm  210  and flexible coupling member  340 . And, the beam-side plate  320  provides a rigid connection between the flexible coupling member  340  and the center beam  400 . The flexible coupling member  340  is flexible such that misalignment between the first axis of rotation A 1  of the headstock swing arm  210  and the third axis of rotation A 3  of the center beam  400  will cause flexing of the flexible coupling member  340 . 
     In addition, the tailstock apparatus-side coupling plate  560  provides a rigid connection between the tailstock swing arm  610  and flexible coupling member  540 . And, the beam-side plate  520  provides a rigid connection between the flexible coupling member  540  and the center beam  400 . The flexible coupling member  540  is flexible such that misalignment between the second axis of rotation A 2  of the tailstock swing arm  610  and the third axis of rotation A 3  of the center beam  400  will cause flexing of the flexible coupling member  540 . 
     The compliance assemblies  300 ,  500  are torsionally stiff, but allow axial flexing. The compliance assemblies  300 ,  500  prevent material fatigue of other components of the workpiece positioner assembly. The compliance assemblies  300 ,  500  save space (i.e., are smaller in size) and less costly than other alternatives. 
     It is noted that, while the embodiment shown in  FIG. 18  includes four evenly spaced bolts/nuts and associated holes joining plates  320 ,  520  to members  340 ,  540 , and four evenly spaced bolts/nuts and associated holes joining plates  360 ,  560  to members  340 ,  540 , different numbers of bolts/nuts/holes can be utilized, such as three, five, six, seven, eight, nine, ten, etc. It is preferable that the bolts/nuts/holes are evenly spaced about a center of the first compliance assembly  300  and the second compliance assembly  500 ; however, uneven spacing could also be used. 
     Seals  321 ,  521  are provided to prevent weld spatter etc. from entering the device. 
       FIG. 19  illustrates an embodiment of a computer  1900  with which an embodiment of the invention may be implemented. Although computer  1900  is depicted with respect to a particular device or equipment, it is contemplated that other devices or equipment (e.g., network elements, servers, etc.) within  FIG. 19  can deploy the illustrated hardware and components of system  1900 . The computer  1900  is programmed (e.g., via computer program code or instructions) to provide the functionality described herein and includes a communication mechanism such as a bus  1901  for passing information between other internal and external components of the computer system  1900 . One or more processors  1903  for processing information are coupled with the bus  1901  to perform a set of operations on information as specified by computer program code. 
     The computer  1900  also includes a memory  1905  coupled to bus  1901 . The memory  1905 , such as a random access memory (RAM) or other dynamic storage device, stores information including processor instructions. The memory  1905  is also used by the processor  1903  to store temporary values during execution of processor instructions. The computer system  1900  also includes a read only memory (ROM)  1907  or other static storage device coupled to the bus  1901  for storing static information, including instructions, that is not changed by the computer system  1900 . The computer  1900  includes a communication interface  1917  that allows the computer  1900  to communicate with other devices or equipment (e.g., network elements, servers, etc.) 
     Information, including user input instructions, is provided to the bus  1901  for use by the processor  1903  from a user interface including a display  1911  and an input device  1913 , such as a keyboard containing alphanumeric keys operated by a human user, a pointing device (such as a mouse or a trackball or cursor direction keys). 
     One or more robots  1915  and motors  1916  (e.g., motor  260 ) can communicate with the processor  1903  via the bus  1901  in order to send and receive data, operating instructions/commands, or other information therebetween. The processor  1903  can control operation of the one or more robots  1915  and motors  1916  using operating instructions/commands in order to control movement of the robots  1915  and/or rotation (e.g., start, stop, direction (e.g., clockwise, counterclockwise), speed, etc.) of an output shaft motors  1916 . 
     It should be noted that the exemplary embodiments depicted and described herein set forth the preferred embodiments of the present invention, and are not meant to limit the scope of the claims hereto in any way. Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.