Abstract:
An end arm manipulator includes a base, an arm pivotably mounted to the base and a workpiece interfacing member coupled to the arm. In another aspect of the present invention, multiple arms are coupled to the base and are movable independent of each other. In still another aspect of the present invention, generally spherical balls are adjustably mounted between a clamping member and a cavity of the base.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention relates generally to workpiece interfacing apparatuses and more specifically to an end arm manipulator for retaining workpiece interfacing tools. 
     It is common to employ fluid powered grippers for engaging sheet metal workpieces. Such grippers are often movably mounted to a robotic or stationary support. Examples of such mounting arrangements are disclosed in the following U.S. Pat. No. 5,647,625 entitled “Gripper” which issued to Sawdon on Jul. 15, 1997; U.S. Pat. No. 5,383,738 entitled “Ball Jointed Links” which issued to Herbermann on Jan. 24, 1995; and U.S. Pat. No. 5,071,309 entitled “Mounting Arrangement for a Multi-Function Arm” which issued to Herbermann on Dec. 10, 1991. 
     Another traditional device is constructed of multiple, extruded metal rails bolted to a generally square shaped frame. The frame is centrally attached to a moving robotic arm. Hoses extend from the hollow, box section rails which are used as air manifolds. Pneumatically powered grippers are adjustably mounted to various points on the rails. However, these traditional devices are custom fabricated for each particular job, are costly to produce and labor intensive to set up. These traditional devices require excessive amounts of actuating fluid due to the indirect right angle mounting of components and due to the use of rails as manifolds. Such conventional units are also relatively heavy and inefficiently packaged thereby causing accurate repeatability concerns, and a circuitous routing of electrical and pneumatic lines which are prone to snagging on adjacent equipment or the workpiece. 
     In accordance with the present invention, the preferred embodiment of an end arm manipulator includes a base, an arm pivotably mounted to the base and a workpiece interfacing member coupled to the arm. In another aspect of the present invention, multiple arms are coupled to the base and are movable independent of each other. In still another aspect of the present invention, generally spherical balls are adjustably mounted between a clamping member and a cavity of the base. The arms are telescopically extendable in a further aspect of the present invention. Yet another aspect of the present invention provides a fluid powered gripping tool or locating tool mounted on either an end or intermediate portion of an arm. Another aspect of the present invention provides a fluid manifold function as an integral part of the base. 
    
    
     The end arm manipulator of the present invention is advantageous over conventional constructions in that the present invention is quickly and easily adjusted for different workpiece set ups utilizing single or multiple arms in standardized packages. This eliminates the cost of individual fabrications and is reusable for other jobs. The present invention is also much more rigid than traditional devices since the present invention manipulator&#39;s arms directly extend between a compact base and the workpiece, as compared to the traditional right angle geometry. The straight geometry construction of the present invention is also more easily packaged in a small work space while further shortening fluid lines and electrical lines. Moreover, the straight or direct geometry construction reduces the volume of fluid consumed compared to the conventional right angle and box framed structure. The majority of the electrical and fluid lines are also advantageously protectively contained within the arms. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing the preferred embodiment of an end arm manipulator of the present invention gripping a workpiece; 
     FIG. 2 is a side elevational view showing the preferred embodiment end arm manipulator in multiple positions and with multiple other preferred workpiece interfacing tools; 
     FIG. 3 is an enlarged and fragmentary side elevational view showing a base, clamp rings, balls and arms of the preferred embodiment end arm manipulator; 
     FIG. 4 is a fragmentary bottom elevational view showing the base, clamp rings, balls and arms employed in the preferred embodiment end arm manipulator; 
     FIG. 5 is an enlarged cross sectional view, taken along line  5 — 5  of FIG. 4, showing the base, a clamp ring and a ball employed in the preferred embodiment end arm manipulator; and 
     FIG. 6 is a fragmentary and exploded perspective view showing the clamp rings, balls, arms and base employed in the preferred embodiment end arm manipulator; 
     FIG. 7 is an enlarged cross sectional view, taken along line  7 — 7  of FIG. 4, showing the base employed in the preferred embodiment end arm manipulator; 
     FIG. 8 is an enlarged and fragmentary side elevational view showing an arm, tube clamp and tool mount employed in the preferred embodiment end arm manipulator; 
     FIG. 9 is an exploded perspective view showing the tool mount and a side elevational view showing a workpiece interfacing tool employed in the preferred embodiment end arm manipulator; and 
     FIG. 10 is an enlarged side elevational view showing the workpiece interfacing tool, a tool mount and the arm employed in the preferred embodiment end arm manipulator. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2, the preferred embodiment of an end arm effector or manipulator  21  is used to retain or transport a workpiece  23 , such as a stamped steel, body side frame of an automotive vehicle, within a manufacturing plant. A robotic arm  25  is centrally bolted to end arm manipulator  21  for moving the manipulator and selectively engaged workpiece to various positions in the factory. Alternately, end arm manipulator  21  can be mounted to a manually moved support or stationary structure mounted to the factory floor. 
     End arm manipulator  21  includes an aluminum base  31 , four aluminum clamp rings  33 , four predominantly spherical balls  35 , four telescoping arms  37  and workpiece interfacing tools as well as their associated mounts. Additional preferred arms  37 ′workpiece interfacing tools and their associated mounts are shown in FIG.  2 . Exemplary preferred tool configurations include grippers  41 ,  43 ,  45 ,  47 ,  49 ,  51 ,  53  and  55 , which each include a circular cylindrically shaped body  71  (see FIG.  9 ), an internally disposed pneumatic driven piston  73  and at least one moving jaw  75  for gripping the workpiece. Grippers  41 - 53  employ one or more pivoting jaws of the type known as the BTM PG-45 style flange gripper, double opening gripper or fixed gripper. Gripper  55  is of a parallel or box jaw type gripper known as the BTM SSLG style gripper. Other preferred workpiece interfacing tools include an electromagnetic coil proximity part-present sensor  77 , a steel locator pin  79  and a vacuum cup  81 . 
     The construction of base  31 , clamp rings  33  and balls  35  can best be observed in FIGS. 3-6. Each clamp ring  33  is a C-shaped member having a side opening  101  and a top opening  103  through which arm  37  and a portion of ball  35  extend, respectively. Each clamp ring  33  further has an internal partially spherical cavity  105  for receiving the respective ball  35 . Each corner of base  31  also has a partially spherical cavity  107  for receiving a corresponding ball  35 . Bolts  109  are employed to loosely secure each clamp ring  33  to base  31 , whereupon the corresponding ball trapped therebetween is pivotally adjusted to a desired orientation. After such a desired set up orientation is achieved, bolts  109  are tightened so as to secure and maintain the respective ball  35  and arm  37  in the final setup position. It should be appreciated, however, that each clamp ring  33  can be unbolted from base and rotated to many different rotational positions such that side opening  101  of each clamp ring  33  can be differently angled relative to base  31 . If necessary, a dowel or screw can be inserted into aperture  121  in each clamp ring  33  for supplementally securing the corresponding ball  35  in its ultimately desired position. 
     A NEMA (National Electrical Manufacturers Association) box  123  is fastened to the bottom of base  31  for containing electrical line or wire connections and controllers. Furthermore, the robotic arm is bolted to a central area  125  of base  31 . 
     A manifold portion  141  of base  31  can be seen in FIGS. 4 and 7. Manifold portion  141  is integral with base  31  and includes a pair of longitudinally elongated bores  143  and multiple transversely extending passageways  145  intersecting each bore  143 . Bores  143  and passageways  145  are all drilled into base  31  although alternately, they may be integrally cast. It may be desired to thread the open ends of bores  143  and passageways to accept standard fittings. The main pneumatic fluid lines or hoses are coupled to the open ends of bores  143  while the individual tool pneumatic lines or hoses are connected to the open ends of respective passageways  145 . Thus, manifold portion  141  of the present invention acts as a very compact, centralized and integral fluid receiving and distributing device. 
     Referring now to FIGS. 3,  6  and  10 , each arm  37  is hollow and MIG welded to a corresponding ball  35  aligned with a first hole  201  in ball  35 . Ball  35  is made as two separate and generally semi-spherical spun halves that are TIG welded together at TIG weld  203 . Arms  37  and balls  35  are both made of steel. For each workpiece interfacing tool  47 , two pneumatic lines  205  are routed from manifold portion  141 , up through a lower hole  207  in base  31  and through a second downwardly facing hole  209  in ball  35 . Pneumatic lines  205  are then routed in arm  37  and are allowed to exit through a laterally extending aperture  211 . These pneumatic lines are then coupled to each fluid powered tool  47  for automatically and remotely activating the tool to grip or disengage workpiece  23 . One or more electrical lines  231  are routed from box  123 , up through hole  207 , hole  209  and then in arm  37 . Electrical lines  231  also exit arm  37  through aperture  211  and are then connected to a Turck switching or position sensing unit  233  mounted to tool  47 . 
     FIG. 8 illustrates the telescopic nature of arm  37 . Arm  37  includes a proximal arm section  401  and a distal arm section  403 . Distal arm section  403  has a slightly smaller outside diameter as compared to the inside diameter of proximal arm section  401 . Thus, distal arm section  403  can be longitudinally slid into and out of proximal arm section  401  depending upon the desired set up length. Furthermore, distal arm section  403  can be rotated relative to proximal arm section  401  depending again upon the desired set up positioning; 360° distal arm section rotational movement is allowed. A tube clamp  405  engages the outside surface of proximal arm section  401  and serves to maintain the desired set up position of distal arm section  403  relative to proximal arm section  401  by tightening of screws  407 . Four inwardly extending tabs of tube clamp  405  serve to slightly compress and crush the adjacent area of proximal arm section  401  thereby frictionally engaging a roughened outside diameter surface of distal arm section  403 . If necessary, a dowel pin  409  or screw can additionally secure the arm sections relative to each other. FIG. 8 also shows an intermediate arm positioning of a tool mount  411  along a generally middle or intermediate portion of arm  37 . 
     An exemplary tool mount  451  is shown in FIGS. 9 and 10. Mount  451  includes a ball and socket joint defined by a mount  453 , a grooved first ball  455 , a swivel rod  457 , a mount ring  459 , a mount plug  461  and a second grooved ball  463 . Second ball  463  is integrally machined as part of rod  457 . Mount plug  461  is fastened to a distal end of arm  37 . Bolts  471  serve to secure mount ring  459  to mount plug  461  thereby compressing and maintaining second ball  463  in its finally adjusted pivotal orientation. Similarly, bolts  473  are secured to maintain mount  453  in its final desired set up position relative to the previously pivoted first ball  455  while also maintaining mount  453  in its desired angular and linear relationship relative to tool  47 . These mount parts are machined from aluminum or steel with various oxide or hard coatings. 
     While the preferred embodiment of the end arm manipulator has been disclosed, it will be appreciated that various other embodiments may be employed without departing from the present invention. For example, the distal end ball and socket tool mounting arrangement can be employed independently of the rest of the invention. Furthermore, any number of ball, arm and clamp ring combinations can be employed with a single base; for example, it is envisioned that two, four and six arm to base combinations would be desirable for many factory applications. Moreover, hydraulic fluid, pneumatic fluid or electrically powered tools of any variety can be mounted to the present invention construction. For example, welding guns or riveting machines can be used. Various materials and fasteners have been disclosed in an exemplary fashion, however, other materials and fasteners may of course be employed. It is intended by the following claims to cover these and any other departures from the disclosed embodiments which fall within the true spirit of this invention.