Patent Publication Number: US-6212784-B1

Title: Three-dimensional robotic scribing system

Description:
Priority claimed based on Ser. No. 60/064,773 filed Nov. 10, 1997. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of measuring apparatus, and more particularly to a novel coordinate measuring equipment employing a programmable position and actuating means for locating a scribe with respect to critically and strategically placing the scribe in a particular angular or in-dash line position with respect to a work surface. 
     2. Brief Description of the Prior Art 
     In the past, it has been the conventional practice to scribe layout lines on a work surface for either whole location or for trimming purposes. Sometimes the work surface is of a three-dimensional, volummetric configuration such as a sphere, cube or cone, as well as a flat surface. In either measuring across the work surface or for whole location purposes, a scribe is normally trained across the work surface in accordance with optical viewing equipment in order to obtain accuracy of location and measurement. Sometimes the location is determined by operator eye coordination which is less efficient and inaccurate. When employing electronic positioning equipment, it is not always possible to arrange for angular or special positioning of the scribe so that a variety of work curved surfaces can be accommodated. Also, difficulties have been encountered when using conventional machines which stem largely from the fact that small incremented steps or joggles are difficult if not impossible for conventional measuring machines to achieve accurate measurement. The difficulties are derived from the fact that the small steps are point-to-point measurements and it is difficult to measure or locate specific points on irregular surfaces. 
     Therefore, a long-standing need has existed to provide a coordinated measuring equipment which is programmable and which is a time-saving process not requiring manual inspection or manual location of scribe points. Such equipment should incorporate the advantages of employing a fully articulated scribe which makes optically measurement or remanufacture possible of component parts so that accuracy of attachment areas in the aerospace and automotive fields are achieved. Thus, assembly time will be increased while adding structural integrity as well as accuracy. 
     SUMMARY OF THE INVENTION 
     Accordingly, the novel three-dimensional robotic scribing system of the present invention avoids the above-noted problems by providing a programmable system that employs a driver computer control that is programmed via a personal computer having a keyboard input. The contoller sends programmed signals to a three-dimensional coordinator circuit which generates X, Y and Z drive signals representing left, right and height positions of a scribe which is in alignment with the surface of a workpiece. Between the three-dimensional coordinate circuit and the scribe is an electronic to mechanical conversion means taking the form of a machine piston which converts the electrical X, Y and Z programmed instructions to a servo and trigger network interfaced with the scribe. Also, an angle position driver directly couples, in parallel, the driver computer control and the three-dimensional coordinating circuit with the servo and trigger network. Therefore, by programming the instructions into the system, the scribe can follow or coordinate with the workpiece surface whether it is flat, curved or irregular. 
     In one form, the scribe itself may include a housing with a reciprocating shaft having a conical pointed end. The shaft is spring-loaded within the housing so as to normally outwardly project from one end of the housing into contact with the workpiece surface. Also, the housing may be clamped by one of several means to the machine ram or piston taking its instructions from the three-dimensional coordinating circuit via the servo and trigger network. Means are employed on the housing, in one version of the scribe, for articulating the scribe shaft into an angular position so as to be more definitely related to the workpiece surface. 
     Therefore, it is among the primary objects of the present invention to provide a novel coordinated measuring apparatus for use in measurement scribing which eliminates time-consuming manual inspection processes. 
     Another object of the present invention is to provide a measuring apparatus which is adapted to measure or follow patterns on a work surface whether it is irregular or regular even if the pattern is represented by small steps or joggles or is a continuous linear line or the like whereby accuracy of measurement is increased so as to result in a decrease in assembly time in the aerospace and automotive industries. 
     Still a further object resides in providing a measuring apparatus which employs a fully articulated scribe for measuring a pattern on a workpiece surface whether the surface is a sphere, a cube, a cone or other irregular surface. 
     A further object resides in providing a novel scribe in a fully programmable measuring system whereby the scribe may a straight scribe, a heavy duty, manually adjustable scribe by means of an electric trigger, a heavy duty, manually adjustable scribe without trigger or may be a light duty scribe for use on an indexable trigger device. 
     Also, the present invention resides in providing a variety of mounting means for detachably connecting the scribe to an actuating ram which is programmably operated through computer and converting circuits whereby the means may take the form of a clamp, a squeeze collet, a lock screw and bolt arrangement, a cam lever or the like. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood with reference to the following description, taken in connection with the accompanying drawings in which: 
     FIG. 1 is a block diagram illustrating the novel system incorporating the three-dimensional robotic scribing device; 
     FIG. 2 is an enlarged longitudinal sectional view of one version of a scribe used in the system shown in FIG. 1; 
     FIG. 3 is a reduced alternate version of a scribe illustrating articulation thereof; and 
     FIG. 4 is another version of the scribe illustrating an alternate mounting means. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a three-dimensional robotic scribing system is illustrated in the general direction of arrow  10  which includes a coordinate driver computer controller  11  which is set by a PC computer  12  through a program input such as a keyboard  13 . A power supply  14  is employed to supply operating current to the system  10 . The pre-programmed coordinate controller  11  receives instructions from the PC and instructs a three-dimensional coordinate circuit  15  as to three-dimensional positions or paths representing X, Y and Z positions. The X and Y positions are indicated on a workpiece  16  having a surface with a pattern or design intended to be measured. The X, Y positions represent right and left movements of a scribe device  17  while the Z position is representative of height. The position coordinate signals from the circuit  15  are received by a mechanical device such as a machine piston or ram  18 , such as solenoid operated, which then operates a scribe  20  carried within a housing  21  of the scribe unit  17 . The coupling or connection between the machine piston  18  and the scribe unit  17  is indicated in broken lines while an alternate operation of another scribe is indicated in solid lines wherein operation of the scribe is through a trigger and servo  22  to a scribe of a different variation, indicated by numeral  23 . Also, it can be seen that for an articulated or angular scribe, an angle position driver  24  is coupled between the coordinate driver controller  11  and the trigger or servo  22 . 
     Thus, depending on the input program from the keyboard  13  through the computer  12  and into the controller  11 , instructions are provided for positioning the scribe  20  via the coordinate network  15  and the angle position driver  24  and/or the machine piston  18 . It is to be understood that the workpiece  16  includes a surface which may be curved, such as on a sphere, a cone, or an irregular surface as the case may appear. 
     Referring now in detail to FIG. 2, another version of scribe is illustrated in the direction of arrow  23  which includes a housing  25  having a reciprocating shaft as a scribe, indicated by numeral  26 . The scribe  26  includes a planted or conical tip  27  that engages the surface of the workpiece  16 . The housing  25  includes an open-ended bore occupied by the shaft of the scribe  26 . A spring  28  forcibly urges the scribe outward so that the conical tip extends from one end of the housing  25 . The resilient means includes a collar  30  having an upper surface against which one end of the expansion spring  28  bears while the opposite end of the expansion spring bears against a washer or shoulder  31  terminating the bore of the housing  25 . 
     It can also be seen that the machine piston  18  which may include a ram is connected to the housing  25  by means of a squeeze collet, a squeeze clamp, a lockscrew and collar arrangement or by a cam lever. As illustrated, a clamp  32  is employed with a tightening or locknut  33 . It is manually adjusted to angle, locked and held in position by means of a capscrew  35 . The position and means for driving the scribe  26  into the angular position is under the control of the angle position driver  24  when instructed by the program introduced through the computer  20  and the coordinate driver controller  11 . 
     Referring now in detail to FIG. 3, another version of scribe is illustrated wherein the end of a housing  34  terminates in a pivot connection  35  with a scribe holder  36  from which the scribe  37  outwardly projects to engage the workpiece. By means of the capscrew  35 , the scribe  37  may be placed in angular positions, as represented by the solid line position or a dotted line position. 
     Referring now in detail to FIG. 4, still another version of the scribe is illustrated in which a housing  40  carries a scribe  41  having a pointed tip which extends beyond one end of the housing. With reciprocating motion, trigger switch  42  allows measuring or qualifying switch  43  to turn off switch  42  when it is not desired to send a trigger signal. 
     It can be seen that any one of the alternate scribe versions can be used with the positioning system  10 , as previously described. Therefore, when it is intended to measure a pattern or design on the surface of workpiece  16  or to coordinate a variety of critical locations thereon, the setting for the scribe is introduced via the input program, such as keyboard  13  where the computer  12  then instructs the controller  11  so that the coordinate network  15  provides proper instructions and locating instructions to the machine piston  18 , such as solenoid operated, for moving the scribe  20 . Alternately, if an angular position is needed as shown by the scribe in FIG. 3, the instructions from the controller are augmented by the angle position driver  24  and through the trigger and servo circuit  22  adjust the scribe  27  similar to the depiction of  37 , as shown in FIG. 3 which is manually adjusted. FIGS. 2-4 inclusive illustrate a variety of scribe constructions and mounting means with respect to the housing which are available for the operator. 
     While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.