Abstract:
A reconfigurable end-effector assembly includes a master boom, a limb, and branches. The branches extend radially outward from the limb. Tandem branch joint assemblies connect the branches to the limb, and include a first and a second branch joint each having a cam lock. Tool modules mounted to the branches are translatable and rotatable with respect to the branches. The joint assemblies rotate and slide with respect to the longitudinal axis of the limb only when the cam lock is released. A configuration tool has an actuator and fingers. The branch joints define openings that are engaged via the fingers. The tool includes a latch which engages the cam lock, and clamps and unclamps the cam lock. A flexible dress package is mountable to the limb and configured to route lengths of conduit to each of the tool modules.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority benefit of U.S. Provisional Application No. 61/828,808, filed on May 30, 2013, which is hereby incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a reconfigurable robot end-effector assembly. 
       BACKGROUND 
       [0003]    Robot end-effectors are used in various manufacturing processes to perform work on a given workpiece. End-effectors may include tool modules with end tools which, depending on the design, can grip, transport, orient, and release the work piece. Certain end-effectors include a main boom, which is grasped and moved as needed by a material handling robot. The limbs of the end-effector extend outward from the main boom. Multiple branches extend radially outward from the limbs to form an array of tool modules. 
         [0004]    The individual tool modules and end tools may be manually adjusted to a desired location and orientation prior to performing a work task. Such end-effectors may facilitate manufacturing processes. However, conventional designs for interconnecting the various limbs and branches, as well as for routing power to the end tools, may remain less than optimal with respect to packaging size, adjustability, and weight. 
       SUMMARY 
       [0005]    An end-effector assembly as disclosed herein is intended to address the aforementioned problems, in part via the use of lightweight tandem branch joint assemblies, each of which utilizes a pair of cam locks having respective handles. The pair of cam locks forms an eccentric joint enabling relatively quick locking/unlocking and repositioning of the various branches of an end-effector assembly. 
         [0006]    The end-effector assembly may include a configuration tool having an actuator. The actuator may be used to directly engage the cam lock handles and the two branch joints of each tandem branch joint assembly. The configuration tool automatically releases the cam locks, and to thereafter rotates and/or linearly positions the branch joints with respect to a given limb, with the particular configuration determined by the design of the workpiece. 
         [0007]    Additionally, a flexible dress package may also be included which routes pneumatic tubes or other flexible conduit to each of the end tools. Unlike prior art packages, the flexible dress package of the present invention does so without carrying the structural load of the branches. 
         [0008]    The above features and advantages, and other features and advantages, of the present invention are readily apparent from the following detailed description of some of the best modes and other embodiments for carrying out the invention, as defined in the appended claims, when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematic plan view illustration of a reconfigurable end-effector assembly having a plurality of configurable tool modules and a configuration tool in accordance with the present disclosure. 
           [0010]      FIG. 2  is a schematic perspective view illustration of a branch portion of the end-effector assembly of  FIG. 1 . 
           [0011]      FIG. 3  is schematic perspective view illustration of an example tandem branch joint assembly as shown in  FIG. 2 . 
           [0012]      FIG. 3A  is a schematic perspective view illustration of a flexible snap-in sleeve that is usable with the tandem branch joint assembly of  FIG. 3  to join separate eccentric branch joints. 
           [0013]      FIG. 4  is a schematic plan view illustration of an example embodiment of the configuration tool shown in  FIG. 1 . 
           [0014]      FIG. 5  is a schematic side view illustration of a flexible dress package usable with the reconfigurable end-effector assembly of  FIG. 1 . 
           [0015]      FIG. 6  is a schematic plan view illustration of the flexible dress package shown in  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Referring to the drawings, wherein like reference numbers refer to like components throughout the several Figures, a reconfigurable end-effector assembly  10  is shown schematically in  FIG. 1 . The end-effector assembly  10  includes a master boom  12  which is connected, via a T-fitting  15  or other suitable connector, to a limb  16  having a longitudinal axis  11 . The limb  16  may have an inner wall  19  as shown in  FIGS. 2 and 4 . The master boom  12  may be positioned anywhere in a Cartesian (xyz) frame of reference, i.e., in free space, as needed by a robot (R)  14 , for instance a multi-axis material handling robot of the type typically used for logistical purposes in a manufacturing facility. As is well understood in the art, such a robot  14  may be programmable, fixed to a stationary or a moveable base, and configured to position the master boom  12  as needed with respect to a workpiece (WP). 
         [0017]    A limb  16  of the end-effector assembly  10  extends orthogonally with respect to the master boom  12  via the T-fitting  15  and provides the necessary transverse structural support for a plurality of branches  18 . Each of the branches  18  supports a tool module  20 , with each tool module  20  including an end tool  22 . The branches  18  may be attached to the limb  16  in a cantilever manner. As described herein, the branches  18  with the attached tool modules  20  are moveable, and thus may be arranged as desired to permit the end tools  22  to attach to or otherwise interact with the workpiece (WP), e.g., a pane of glass, a structural body panel, or the like. 
         [0018]    In keeping with the non-limiting body panel example, the corresponding end tools  22  are shown throughout the various Figures as pneumatic suction cups of the type used to secure and move automotive or other body panels without marring the finished show surfaces thereof. However, other end tools  22  may be readily envisioned within the intended scope of the present invention, such as pinchers, clamps, spray nozzles, etc., and therefore the particular construction of the end tools  22  may vary. 
         [0019]    The tool modules  20  shown in  FIG. 1  are connected to a corresponding branch  18  via a linear/rotatable locking mechanism  24 , i.e., any device or mechanism which allows the tool modules  20  to be locked in place in both a rotational (arrow A) and linear (arrow B) direction with respect to a longitudinal axis  13  of the branch  18 , and selectively unlocked in either direction to allow translation or rotation of the tool module  20  with respect to the branch  18 . An example locking mechanism that may be suitable for use as the locking mechanism  24  is disclosed, for instance, in Lin et al. (US 2011/0182655), which is hereby incorporated by reference in its entirety. Each branch  18  extends radially outward from the longitudinal axis  11  of limb  16 . In turn, the various branches  18  are connected to the limb  16  via a corresponding tandem branch joint assembly  30 . 
         [0020]    The tandem branch joint assembly  30 , the structure of which is described in further detail below with reference to  FIGS. 2 and 3 , allows for quick adjustment and repositioning of each of the branches  18  with respect to the axis  11  of limb  16 , as indicated by arrows C and D in  FIG. 1 , either manually or via a configuration tool (CT)  50 . An example of such a configuration tool  50  is described below with reference to  FIG. 4 . Each tandem branch joint assembly  30  joins different branches  18  to the limb  16  in an eccentric configuration. The configuration tool  50  of  FIG. 4  can directly interface with a given tandem branch joint assembly  30  to selectively unlock the tandem branch joint assembly  30  and reposition the branches  18  as needed, or an operator could manually accomplish this task. 
         [0021]      FIG. 2  depicts a separated branch segment of the end-effector assembly  10  of  FIG. 1  along axis  13 , i.e., from the tandem branch joint assembly  30  to the tool module  20 . The tandem branch joint assembly  30  is locked into a desired orientation with respect to the axis  13  via the locking mechanism  24 . Flexible conduit  63 , e.g., pneumatic tubing or hose, allows a force to be delivered to the end tool  22 , in this instance a vacuum provided via an end tool  22  in the form of a suction cup. In other embodiments, the conduit  63  may provide electrical power or hydraulic fluid power. The tandem branch joint assembly  30  is likewise locked into a desired orientation with respect to the axis  11  of the limb  16 . 
         [0022]    The term “tandem” specifically refers to the use of two identical but inversely-oriented, eccentric branch joints  32 A and  32 B. The branch joints  32 A and  32 B are positioned or configured independently, but can be coupled into an integral tandem unit described below. Each branch joint  32 A and  32 B includes a pair of inner walls  33  and  37  each defining an opening within which the limb  16  and branch  18  are respectively received. The branch joints  32 A,  32 B are then securely clamped to the branch  18  via a fastener  35 . A cam lock  34  is provided at each of the branch joints  32 A,  32 B, i.e., two cam locks  34  per tandem branch joint assembly  30 , to thereby securely clamp the branch joints  32 A and  32 B to the limb  16 . 
         [0023]    When clamped, the cam locks  34  securely lock the tandem branch joint assembly  30  to the limb  16  in the axial and rotational directions. The tandem branch joint assembly  30  may be simply unclamped via actuation of the cam locks  34  to allow the tandem branch joint assembly  30  to freely slide along or rotate about the axis  11 , i.e., respective arrows C and D in  FIG. 1 . Although omitted from  FIG. 2  for simplicity, the inner walls  33 ,  37  may be provided with a friction interface such as a knurl pattern, splines, or friction material so as to minimize the chance that, over time, a clamped cam lock  34  may still move with respect to the axis  11 . 
         [0024]    Referring to  FIG. 3 , the tandem branch joint assembly  30  is shown in a clamped position relative to a portion of the limb  16 . Optional homing markers (M) may be marked or scribed on various surfaces of the end-effector assembly  10  of  FIG. 1 , shown here as along the limb  16 , so as to facilitate reconfiguration in certain instances. Configuring the end-effector assembly  10  to the homing markers (M) of  FIG. 3  may be manually accomplished. Therefore, the homing markers (M) should be easy to identify to a human operator, with placement such as at physical limits of a range of travel of any joint, and/or at positions that are free from interference with other parts of the end-effector assembly  10 . The homing markers (M) provide reference lines or points for quickly resetting all of the joints of the end-effector assembly  10  to a desired configuration, which may be particularly useful after a build cycle or tool crash. In some embodiments, machine vision may be used to image the homing markers (M) so as to automate the reconfiguration process, or an operator can also use the homing markers (M) to manually reconfigure the set up. 
         [0025]    Referring to  FIG. 3A , the tandem branch joint assembly  30  of  FIG. 3 , although constructed of separate branch joints  32 A and  32 B, may form an integral tandem unit via use of a flexible snap-in sleeve  40 . The flexible snap-in sleeve  40  may include a pair of flanges  42 ,  43  of a flexible rubber or polymer material, with the flanges  42 ,  43  separated by a length of annular side wall  41 . The annular side wall  41  may cut as shown to define an angled slot  45 . The presence of the slot  45  allows the flanges  42  and  43 , the sides of which are visible in the view of  FIG. 3 , to partially collapse when the side wall  41  is compressed. This in turn allows the sleeve  40  to pass through the tandem branch joint assembly  30 . The sleeve  40 , being resilient, springs back into the generally cylindrical shape of  FIG. 3A  once the flange  43  is entirely through the branch joints  32 A and  32 B, with the flanges  42  and  43  flanking the branch joints  32 A,  32 B. When the cam locks  34  are unlocked, each branch joint  32 A and  32 B can articulate independently on the limb  16  while still linearly translating together along axis  11 . 
         [0026]    Referring to  FIG. 4 , the end-effector assembly  10  of  FIG. 1  may be automatically adjusted via the configuration tool  50  as noted above. In an example embodiment, the configuration tool  50  includes an actuator housing  53  with actuators  52  and  52 A, which impart motion as indicated by arrow J and/or arrows F and G as set forth below. The configuration tool  50  may include a logic board  58 , actuating fingers  54  moved via the actuator  52 , and a cam latch  55  that moves via actuator  52 A, and which engages the handle  36  of the cam lock  34 . The actuators  52  and  52 A may be any pneumatic, hydraulic, or electro-mechanical device configured to impart a force to the actuating fingers  54  and the cam latch  55 , for instance rotatory ball screws or other linear or rotary actuators. 
         [0027]    A robot (not shown) moves the configuration tool  50  into position with respect to a given branch joint  32 A or  32 B, and, via signals issued to the logic board  58 , selectively closes the actuating fingers  54  via the actuator  52 . The partially-closed and fully-closed positions are shown via the respective solid and broken lines at E 1  and E 2  in  FIG. 4 . Continued motion away from the branch joint  32 A or  32 B moves the actuating fingers  54  into a fully open position, i.e., disengaged from the branch joint  32 A or  32 B. The actuator  52  moves the actuating fingers  54  far enough to clear the branch joint  32 A or  32 B, then closes the actuating fingers  54  to grasp the branch joint  32 A or  32 B. An end  39  of the actuating fingers  54  enters the locator opening  38  to directly engage the particular branch joints  32 A or  32 B. In an alternative embodiment, only one of the actuating fingers  54  moves while the other remains fixed, a configuration that may reduce complexity without sacrificing much in the way of the demonstrated pincher functionality. 
         [0028]    The cam latch  55  of  FIG. 4  may be generally L-shaped as shown or otherwise sufficiently shaped to receive and engage the handle  36  of the cam lock  34 . An arm  56  may be connected to or formed integrally with the cam latch  55  and extend to another actuator  52 A within the actuator housing  53 . During end-effector configuration, the actuator  52  partially closes the actuating fingers  54  such that the end  39  of each actuating finger  54  enters the locator opening  38  to partially engage the particular branch joint  32 A or  32 B. In turn, the cam latch  55  and the connected arm  56  move to engage the handle  36  of the cam lock  34 . The other actuator  52 A then moves the cam latch  55  and the connected arm  56  vertically to position I, and thus the handle  36  of the cam lock  34  to position H, i.e., toward the actuator  52 A (arrow F) to unlock the branch joint  32 A or  32 B for end-effector reconfiguration. 
         [0029]    To reconfigure the tandem branch joint assembly  30 , the actuating fingers  54  are then fully closed by the actuator  52  for secure grasping and moving of the branch joint  32 A or  32 B while the configuration tool  50  is rotated and translated via a material handling robot (not shown). At the desired branch joint position, the actuator  52 A drives the cam latch  55  and the connected arm  56  in the direction of arrow G and thereby moves the handle  36  of the cam lock  34  to a locking position, and thereby locks the branch joint  32 A or  32 B. 
         [0030]    Referring to  FIGS. 5 and 6 , a flexible dress package  60  is shown in side and top (plan) views, respectively. The dress package  60  may be used with the end-effector assembly  10  of  FIG. 1  to house and route lengths of flexible conduit  63  to the various end tools  22  (see  FIGS. 1 and 2 ). The conduit  63  conducts the necessary vacuum, compressed air, hydraulic fluids, or electricity to the end tools  22 , depending on the particular construction, for activating the end tools  22 . The conduit  63  may be provided in suitable lengths that permit a sufficiently wide range of motion. Unlike prior art flexible dress packages, the design of  FIGS. 5 and 6  does not carry the structural load of the various branches  18 , instead providing only the necessary support for flexible and rigid carriers  70 ,  72 , respectively. 
         [0031]    As best shown in  FIG. 5 , the limb  16  may be circumscribed by a boom sleeve  64 . Branch rails  62  radiate outward from the branch joint  32 A or  32 B, with each branch rail  62  defining a U-channel  61  within which the conduit  63  is received. The locking mechanism  24  is positioned along a given branch  18  (see  FIG. 1 ) with respect to the branch rails  62  separate from the flexible dress package  60 , with the end of the conduit  63  terminating at the corresponding end tool  22  (see  FIG. 1 ) disposed near the locking mechanism  24 . 
         [0032]    An I-beam  68  extends parallel to the axis  11  of the limb  16  shown in  FIG. 1  and supports the flexible carrier  70  and rigid carrier  72 , with the rigid carrier  72  surrounding/circumscribing a given tandem branch joint assembly  30 . Thus, the carriers  70 ,  72  are allowed to move linearly along a branch  18  (see  FIG. 1 ), but the carriers  70 ,  72  do not rotate in conjunction with an articulation of the branch  18  (see  FIG. 2 ). 
         [0033]    The flexible and rigid carriers  70  and  72 , respectively, are shown in  FIG. 6  with respect to the I-beam  68 . Cable track constructed of nylon or other rigid, wear-resistant material is a particular type of flexible carrier  70  that may be used with the flexible dress package  60 , although any other design could be used that is capable of receiving the conduit  63  therein and shielding it from damage without restricting its motion. The conduit  63  housed within the flexible carrier  70  may be routed to a central manifold  75 , e.g., a pneumatic manifold in the example of suction cups used for the end tools  22  of  FIG. 1 . Such a manifold  75  may be used to route the conduit  63  to the various points of use. Use of the manifold  75  also allows the flexible carrier  70  of each branch  18  to be about half of the length of the I-beam  68 . 
         [0034]    The end-effector assembly  10  as described herein, whether automatically configured via the configuration tool  50  of  FIGS. 1 and 4  or manually configured, thus provides the benefit of a quick release, light weight clamping joint design. The present design retains advantages of existing branch and limb-type end-effectors. In an automated production line, where one material handling robot typically services one station, end-effector reconfiguration may be achieved via batch or mixed runs. For a batch run, with longer time periods available during the changeover from one batch of parts to another, each robot can park its end-effector assembly  10  on a passive reconfiguration stand (not shown). 
         [0035]    Once parked, the robot can pick up a configuration tool  50  (see  FIG. 4 ) and reconfigure the end-effector assembly  10 . Another configuration tool may be used to reconfigure the locking mechanism  24 , for instance as described in US2011/0182655, which is hereby incorporated by reference in its entirety. If time allows, one or more stands on a sliding rail may serve all of the robots. For mixed runs, the changeover is, at most, one cycle time to keep production flowing. Here, the robot may place the end-effector assembly  10  in an active configuration stand (not shown), with such a stand having a set of configuration tools  50  that can configure all tandem branch joint assemblies  30  automatically and simultaneously in a short period of time. 
         [0036]    The detailed description and the drawings or figures are supportive and descriptive of the invention, but the scope of the invention is defined solely by the claims. While the best mode, if known, and other embodiments for carrying out the claimed invention have been described in detail, various alternative designs and embodiments exist for practicing the invention defined in the appended claims.