Abstract:
A system and method for joining two articles together is disclosed. The nest and hold station of the present invention includes a positive alignment system which comprises two or more upper arms which extend from the upper nest member and a like number of lower cooperative alignment components arranged on or about the lower nest member. The cooperative alignment system may be defined by pins fitted to the upper arms and pin-receiving apertures formed in the lower cooperative alignment components.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority to U.S. Provisional Serial No. 60/407,199, filed Aug. 29, 2002. 
     
    
     
       TECHNICAL FIELD  
         [0002]    The present invention generally relates to an apparatus for the joining of articles. More particularly, the present invention relates to an apparatus for joining at least two components together that are nested between an upper nest member and a lower nest member which includes an alignment system for aligning the upper nest member with the lower nest member.  
         DISCUSSION  
         [0003]    Modern vehicle panels frequently are composed of an outer panel or skin and an inner panel that provides the outer skin with integral strength. These panels are joined together through a variety of methods, including welding, flanging and hemming through metal forming.  
           [0004]    Flanging and hemming (through metal forming) are the preferred methods of joining panels because of the resulting positive connection at a relatively low cost. An example of a flanging and hemming machine may be found in the Applicant&#39;s U.S. Pat. No. 5,454,261, issued on Oct. 3, 1995, for HEMMING MACHINE AND METHOD OF OPERATION. Other examples of known panel joining machines are set forth in U.S. Pat. No. 6,029,493 issued on Feb. 29, 2000, to Maier et al. for DEVICE FOR HEMMING OF SHEET METALS, PARTICULARLY OF COACHWORK SHEET METALS IN AUTOMOBILE MANUFACTURE, U.S. Pat. No. 6,314,783, issued on Nov. 13, 2001, to Patrick for ELECTROMECHANICAL HEMMING APPARATUS AND METHOD, and U.S. Pat. No. 6,378,348, issued on Apr. 30, 2002, to Katsube for HEMMING PROCESS AND HEMMING APPARATUS.  
           [0005]    While all providing advancements in the state of the art of machines for joining two panels together, opportunity for design and feature improvement is always available. One of the difficulties of some known panel joining devices has to do with alignment. As is known in the art, the panels to be joined are placed between the separated and spaced-apart upper and lower nest members. Once in position, the upper nest member is moved toward the lower nest member until the panels are firmly captured there between. A difficulty arises in that the upper nest member and the lower nest member may move out of alignment with one another during the nesting process, resulting in the panels being improperly joined.  
           [0006]    Accordingly, a system which allows the proper alignment of the upper nest member with the lower nest member while the panels to be joined are captured there between remains wanting.  
         SUMMARY OF THE INVENTION  
         [0007]    In general, the present invention provides an apparatus for aligning an upper nest member of a panel fastening machine with the lower nest member which overcomes the known problems of the prior art.  
           [0008]    Accordingly, it is an object of the present invention to provide such an apparatus which offers a positive and direct method of aligning the members.  
           [0009]    It is a further object of the present invention to provide such an apparatus which offers a direct and positive alignment system without interfering with the operation of the working tool.  
           [0010]    Still a further object of the present invention is to provide such an apparatus at a relatively low cost that is easy to operate and maintain.  
           [0011]    These and other objects of the present invention are achieved by an apparatus which includes a positive alignment system which comprises two or more upper arms which extend from the upper nest member and a like number of lower cooperative alignment components arranged on or about the lower nest member. The cooperative alignment system may be defined by pins fitted to the upper arms and pin-receiving apertures formed in the lower cooperative alignment components. Other alignment arrangements, such as heal blocks or cone-shaped alignment elements and receivers are possible.  
           [0012]    Briefly, in operation, the panels to be joined are placed between the upper and lower nest members. One of the nest members is moved toward the other nest member and the alignment system functions to maintain proper alignment between the nest members during the critical panel capturing phase in which the panels are effectively held together between the panels. The joining process is undertaken and, when completed, the completed article is removed. Between joining procedures the upper nest member and the lower nest member are moved away from one another, moving the alignment components away from one another simultaneously, thereby allowing the next pair of panels to be joined to be easily inserted between the upper nest and the lower nest.  
           [0013]    Other objects and features of the present invention will become apparent as the description proceeds.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    The present invention will be more fully understood by reference to the following detailed description of the preferred embodiments of the present invention when read in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout the views, and in which:  
         [0015]    [0015]FIG. 1 is a perspective view of a nest and hold station according to a first embodiment of the present invention;  
         [0016]    [0016]FIG. 2 is a top plan view of the nest and hold station of the present invention according to a second embodiment of the present invention; and  
         [0017]    [0017]FIG. 3 is a sectional view of the nest and hold station of the present invention taken along lines  3 - 3  of FIG. 2.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]    The drawings disclose the preferred embodiments of the present invention. While the configurations according to the illustrated embodiment are preferred, it is envisioned that alternate configurations of the present invention may be adopted without deviating from the invention as portrayed. The preferred embodiments are discussed hereafter.  
         [0019]    Referring to FIG. 1, a nest and hold station to the present invention, generally illustrated as  10 , is shown. The nest and hold station  10  includes an upper nest member  12  and a lower nest member  14 . It is to be understood throughout the description of the present invention that the illustrated configurations of the components, including the upper nest member  12  and the lower nest member  14 , are used for illustration only and that other configurations may well be used. The lower nest member  14  is mounted on a base  15 . (The base  15  may be a separate unit or may, in fact, be the shop floor.)  
         [0020]    A vertical drive unit  16  is provided for selectively moving the upper panel  12  toward the lower panel  14 . The drive unit  16  is fixedly mounted to the base  15 . Of course, it could well be the case that the lower panel  14  is moved toward the upper panel  12  or both panels  12 ,  14  are moved toward one another. Accordingly, only one drive unit  16  is illustrated but this arrangement may be modified by the addition of other drive units (not shown).  
         [0021]    A joining tool  18  is shown in its between-joining position. The joining tool  18  is known in the art and is only described herein in the most rudimentary way. The joining tool  18  may be of a variety of types, including the illustrated roller type. The illustrated variation of the joining tool  18  includes a base  19 , a robotic arm  20  and a forming roller  22 . The robotic arm  20  is multi-jointed and is driven by a robotic driver (not shown) as is known in the art.  
         [0022]    While only one joining tool  18  is illustrated it is to be understood that additional working tools may be included as speed of operations require. Specifically, where operations may move relatively slowly one working tool may be adequate. However, where it is desired that joining operations should be accelerated, additional working tools are to be added.  
         [0023]    As illustrated in FIG. 1, the nest and hold station  10  is in its open position which is the position that the nest and hold station  10  would assume between hemming operations. In this position panels to be joined (not shown) may be readily inserted between the upper nest  12  and the lower nest  14 . Similarly, the resulting joined article may be removed from the nest and hold station  10  once the joining operation has been completed.  
         [0024]    Proper alignment between the upper nest member  12  and the lower nest member  14  is accomplished by the present alignment arrangement which comprises two upper arms  24 ,  24 ′ and two lower cooperative alignment components  26 ,  26 ′. The two upper arms  24 ,  24 ′ may be removably attached to the upper nest member  12  for interchangeability or may be integrally formed therewith.  
         [0025]    As illustrated, the two lower cooperative alignment components  26 ,  26 ′ are fixedly attached to the base  15 . (Alternatively, the two lower cooperative alignment components  26 ,  26 ′ may be integrally associated with the lower nest member  14 .) It is to be understood that additional upper arms and a like number of lower alignment components may be added as desired which may be the case for very large joining machines.  
         [0026]    As illustrated, each of the upper arms  24 ,  24 ′ includes an alignment pin  28 ,  28 ′ respectively. The pins  28 ,  28 ′ are in vertical alignment with respective pin-receiving apertures illustrated as  30 ,  30 ′.  
         [0027]    Of course, a variety of configurations may be selected for the alignment arrangement and the pin and pin-receiving configuration set forth is for illustrative purposes. For example, the pin and pinreceiving configuration may be substituted for by a male and female arrangement in which the male component is cone-shaped and the female receiver is cone-shaped. In addition, a heal block arrangement may be used in lieu of or in addition to the pin and pin receiver arrangement described above.  
         [0028]    [0028]FIG. 2 is a top plan view of an alternative embodiment of the nest and hold station of the present invention. The nest and hold station shown herein, illustrated as  10 ′, differs from the nest and hold station  10  shown in FIG. 1 in that a single joining tool  18  is shown as being associated with the nest and hold station  10 . As shown in FIG. 2, an additional joining tool  18 ′ having a base  19 ′, a robotic arm  20 ′ and a forming roller  22 ′, is included. This arrangement has particular application for high speed hemming operations as discussed above.  
         [0029]    [0029]FIG. 3 is a sectional view of the apparatus of the present invention taken along lines  3 - 3  of FIG. 2. In this figure the nest and hold station  10  (which could also be the nest and hold station  10 ′ of FIG. 2) is illustrated as being positioned in its panel-holding mode. A pair of panels for joining—A and B—are illustrated captured and held between the upper nest  12  and the lower nest  14 . In this illustration, panel A is the inner panel and panel B is the outer panel. Accordingly, the outer dimensions of panel B generally extend beyond those of panel A as illustrated.  
         [0030]    In its holding position, the alignment pin  28  of upper arm  24  has been inserted into its associated pin-receiving aperture  30  of lower cooperative alignment component  26 , thus perfecting alignment of the upper nest member  12  and the lower nest member  14 . With the panels A and B thus held in proper alignment with respect to one another, the joining operation is undertaken by movement of the joining tool(s)  18 . The arm  24  is formed such that the alignment pin  28  and the pin-receiving aperture  30  are spaced apart from the upper nest member  12  and the lower nest member  14 , thus allowing the forming roller  22  easy access to the portion of the panel B that needs to be rolled over the panel A as shown in FIG. 3.  
         [0031]    This aspect of the invention is clearly shown in FIG. 2. With reference thereto, the joining tools  18 ,  18 ′ are operated for joining the two panels A and B. The joining tools  18 ,  18 ′ are positioned such that the robotic arms  20 ,  20 ′ have extended their respective forming rollers  22 ,  22 ′ into position approximately between the two upper arms  24 ,  24 ′ and two lower cooperative alignment components  26 ,  26 ′. As may be seen, the forming rollers  22 ,  22 ′ easily execute the joining operation without interference from the alignment components of the present invention.  
         [0032]    The general operation of the apparatus of the present invention will now be described. The upper nest member  12  and the lower nest member  14  are initially moved to their spaced apart configuration shown in FIG. 1. As shown therein, the upper arms  24 ,  24 ′ are also spaced apart from their respective lower cooperative alignment components  26 ,  26 ′. With the nest and hold station in this position, the panels A and B to be joined are readily placed between the upper nest member  12  and the lower nest member  14 .  
         [0033]    With the panels A and B in place, the joining operation is initiated. According to the preferred embodiment, the upper nest member  12  is moved toward the lower nest member  14  as selectively driven by the drive unit  16 . Movement of the upper nest member  12  toward the lower nest member  14  continues until the panels A and B are firmly held together. During the movement of the upper nest member  12  toward the lower nest member  14 , proper alignment is effected by the entry of the alignment pins  28 ,  28 ′ into their respective pin-receiving apertures  30 ,  30 ′.  
         [0034]    Thus positioned, the joining tools  18 ,  18 ′ (assuming a second joining tool is used) are engaged and the robotic arms  20 ,  20 ′ respectively drive their associated forming rollers  22 ,  22 ′ onto and around the panels A and B to undertake the joining operation. As has been described, the forming rollers  22 ,  22 ′ have ready access for undertaking and completing the joining process between the alignment components of the present invention.  
         [0035]    Once joining is completed, the drive unit  16  is again engaged, but this time in the reverse direction so as to move the upper nest member  12  away from the lower nest member  14 . The completed article is removed and the nest and hold station of the present invention is prepared for its next joining operation.  
         [0036]    Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification and following claims.