Abstract:
A removable stem for handling and transporting articles such as optical lens blanks during “wet processing” is disclosed. The stem is dimensioned and configured to support such articles particularly in liquid baths, while directing “wet” materials along the surface of the stem and away from flow onto the article. The stem further provides a drip collection point to avoid disturbing the surface of a “wet bath” while an article is immersed in the bath.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates generally to the processing of articles of manufacture such as, for example only, optical lenses formed of molded plastic and similarly moldable or extrudable materials. More specifically, this invention relates to the handling of such articles during surface treatment processing, when it is desirable to reduce the number and size of contact areas between an article and the transport equipment that engages the article as it is moved through the treatment process. 
         [0003]    2. Description of the Related Art 
         [0004]    Automated equipment for transporting articles through surface treatment and other manufacturing processes have been known and widely used for many years. In the prior art, such equipment has generally transported articles through so-called “wet processing” operations using physical gripping devices, often called “chucks” that engage two or more surfaces of the article in the well-known manner of vises or mechanical pincers having two or more jaws. 
         [0005]    A serious limitation of the use of such known devices for transporting articles, for example, optical lens blanks, through so-called “wet” manufacturing processes that may involve treatment with relatively free-flowing materials such as powder or liquids, is the often uncontrolled flow of materials from the transport mechanism or gripping device onto the article being treated. Another serious limitation often entails disturbance of the surface of the “wet material” by the article-gripping device when a treated/coated article is being withdrawn from immersion in the material. It is well-known that “ripple effects” in such treatment materials may adversely affect the finished surface of the treated article. These limitations relate closely to the tendency of such materials to collect, i.e. accumulate, on the structure of the gripping device, and/or between the gripper and the article, at the points of contact. Materials that accumulate in this manner frequently result in adverse effects on the quality of the article being treated, in that the surface of the article may develop undesired drip marks from material flowing off the “chuck” structure, or the intended coatings may develop unintended and undesirable localized variations in specified parameters such as thickness. 
         [0006]    The present invention addresses this and other such processing problems, and specifically problems associated with “wet treatment” processes wherein articles are raised and lowered vertically for immersion in a treatment “bath”, by disclosing a unique article processing stem that is temporarily and removably attached to each article that is to be processed. The processing stem has unique shape parameters and is attached to the article in a specific orientation to reduce possible accumulations of liquid treatment materials and concurrent adverse effects on the liquid and on the surface of a treated article. In turn, the stem may then be mounted to or engaged by any suitable form of transport carrier for transporting the article through one or more liquid treatment processes, with significantly reduced possibility of adverse effects on the quality of the finished article. And finally, the material that forms the processing stem, as well as the nature of the joint between the stem and the article may be selected so that the stem can be detached readily from the article, when desired. 
         [0007]    The readily detachable article processing stem disclosed herein significantly restricts the possibility of adverse effects resulting from support of an article while it is being subjected to “wet processing” treatments. This is accomplished at least in part by interposing the detachable stem between the treated article and the well-known structure of a transport/gripping chuck or other support/transport mechanism. In this regard, the stem of this invention represents a controlled and controllable single-point connection which is positioned and dimensioned in the most efficacious manner taking into account both the nature of the article and the treatment process. The stem in effect serves to isolate the transport/support mechanism from the article. That is, the temporary processing stem of the invention represents a “sacrificial” portion of the article, for which adverse processing effects are substantially irrelevant and which may be sacrificed, discarded, or reused at the end of the desired treatment. In this regard, it should be understood that the term “sacrificial” is being used to suggest the independence of the stem and the article to which it is temporarily attached, rather than to suggest any necessity to “sacrifice” or discard the stem after it has been used. 
         [0008]    The processing stem of this invention may be separated readily from the processed article in any suitable and well-known manner such as, for example, physical cutting, or mechanical pulling or breaking, or release of the connection by heating or chemical dissolution. For example, either the stem or the connection between the stem and the article may be provided with a controlled, frangible nature, allowing the two parts to be broken apart conveniently along a desired parting line in any well known manner. And, as a further example, once the connection has been released, the separated article may be received gently and without damage by a suitable gripping mechanism or in a container or receptacle of any suitable kind for further use and handling. 
       SUMMARY OF THE INVENTION 
       [0009]    The processing stem article of this invention comprises a removable auxiliary structure for holding other articles temporarily in a stable initial position; it is contemplated that the invention will be used in association with a supply source of stem elements, a placement mechanism for locating the stems in attachment position relative to the articles, and a securing mechanism for attaching a stem to an article when the two items have been correctly positioned relative to each other. It is considered evident to those having skill in the related art that various forms and types of apparatus for attaching the stem of the invention to other articles, either manually or mechanically, are readily conceivable and will not be further described in detail herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a simplified elevation view of one embodiment of an attachment stem affixed to a generally circular optical lens blank in accordance with this invention. 
           [0011]      FIG. 2  is a simplified elevation view of another embodiment of an attachment stem affixed to a circular optical lens blank in accordance with this invention. 
           [0012]      FIG. 3  is a simplified elevation view of still another embodiment of an attachment stem affixed to a circular optical lens blank in accordance with this invention. 
           [0013]      FIG. 4  is a simplified elevation view of a further embodiment of an attachment stem affixed to a non-symmetrical optical lens blank in accordance with this invention. 
           [0014]      FIG. 5  represents a simplified elevation view showing a plurality of attachment stems in accordance with  FIG. 1 , having lens blank articles attached and each stem being mounted to a transport/carrier mechanism in accordance with this invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0015]    Referring now to  FIG. 1  of the drawings, it can be seen that an article processing stem [ 20 ] in accordance with this invention has a generally elongate body member [ 22 ] having a transport/carrier suspension portion [ 24 ] at one end thereof and a drip collection end portion [ 26 ] at the opposite end thereof, remote from said suspension portion. An intermediate portion [ 28 ] of body member [ 22 ] extends between said suspension portion [ 24 ] and said drip collection end portion [ 26 ]. An article mounting support portion [ 30 ] extends from said intermediate body portion [ 28 ] and terminates in an article-mounting surface [ 32 ]. 
         [0016]    In practice, mounting surface [ 32 ] is separably attached as explained herein to an article [ 14 ] along an outer peripheral edge [ 12 ] of the article, to couple the article to a transport mechanism for carrying one or more articles through a “wet” processing operation or operations. In this regard, articles [ 14 ] should be recognized as “work pieces” with which the stems of this invention are intended to be used, but they do not in any respect comprise an integral part of the invention. 
         [0017]    It will be obvious to those skilled in the related art that carrier/transport mechanisms of any well known type may be employed to transport articles using the stems of this invention during and through so-called “wet processing” operations. Accordingly, details of such transport/carrier mechanisms are not set forth herein and are represented only generally by carrier plate [ 50 ] in  FIG. 5 , to facilitate understanding of the invention. With reference to  FIG. 5 , a simplified, partially cross sectioned view of an illustrative stage of a wet a processing treatment using the present invention is shown, in which a plurality of articles [ 14 ] attached to separate processing stems [ 20 ] are first lowered in a vertical direction into and then supported within a fluid “bath” [ 60 ], the bathing fluid being confined in a suitable fluid container [ 62 ]. Each processing stem [ 20 ] is coupled to and suspended from the carrier plate [ 50 ] by engagement of the suspension portion [ 24 ] of stems [ 20 ] in suitably configured suspension elements, [ 52 ] of carrier [ 50 ]. 
         [0018]    In the processing stage suggested in  FIG. 5 , the lower surface [ 51 ] of carrier plate [ 50 ] includes a plurality of suspension elements [ 52 ] which are formed as through openings in surface [ 51 ], and are dimensioned to receive the resiliently displaceable fork-shaped arms [ 25 ] of suspension portions [ 24 ]. That is, the fork-shaped arms [ 25 ] are configured in any well-known manner to “snap” into and out of openings [ 52 ] in a readily engageable and releasable manner. For this purpose, fork-shaped arms [ 25 ] should be understood to represent only one suitable form of suspension portion, and other and various forms of separable/releasable suspension means may be used within the spirit of the invention. In a preferred form, the separable suspension portion will include at least one resilient detent member, such as one of the two arms of fork [ 25 ] to facilitate engagement and disengagement of the suspension portion [ 24 ] with carrier plate [ 50 ]. And, specifically, fork-shaped arms may be formed of suitable, well-known resilient material such as moldable plastic. In another preferred form, the processing stem of this invention may be integrally formed as one piece of such suitable material. If desired, opening elements [ 52 ] and suspension portions may be configured so as to restrict rotation of stems [ 20 ] about the imaginary vertical axis extending through each of elements [ 52 ] so as to maintain positioning of the stems [ 20 ] (and articles [ 14 ]) relative to each other during processing/treatment operations such as while the articles are being vertically lowered into and raised out of a treatment “bath” [ 60 ]. For example, arms [ 25 ] may have a rectangular cross-section along line C-C (see  FIG. 1 ), and openings [ 52 ] may be similarly shaped to prevent rotation of the cross section within the opening. In this context, the term “rectangular” should be understood to include a square shape as well. 
         [0019]    As shown in  FIG. 5 , articles [ 14 ], attached to stems [ 20 ] are generally fully immersed in a liquid bath [ 60 ] so that the uppermost edge [ 14   a ] of each article is at or just beneath the surface of the bath. It will be seen that the illustrated stems [ 20 ] of this invention are configured to assure that a minimal portion [ 28   b ] of intermediate stem body portion [ 28 ] is positioned vertically above an attached article [ 14 ] when the article is submerged in bath [ 60 ]. This configuration helps to assure that any residual amount of fluid remaining on the surface of body portion [ 28   b ] when the assembly is lifted vertically from a “bath” will be guided to run downwardly along that body portion toward drip collection point [ 26   a ] before any part of the fluid can “drip” downwardly onto an underlying portion of an attached article [ 14 ]. 
         [0020]    It should now be apparent that drip collection point [ 26   a ] has been characterized as a “point” in the context of that point being a location on the stem structure of the invention. However, it should be noted also that collection point [ 26   a ] preferably may also have the tapered physical shape of a “point” so as to facilitate separation of accumulated treatment material from the outer surface of the stem in a well known manner. In this context, the pointed shape may be either three dimensional as in the conical form on the point of a pin, or two dimensional as in a wedge-shape. 
         [0021]    Referring again to  FIGS. 1 and 5  of the drawings, it may be seen that processing stems [ 20 ] are intended to be used by suspending them in a downwardly depending direction from suspension portion [ 24 ] at the highest elevation to drip collection end portion [ 26 ] at the lowest elevation. That is, it will be understood that body [ 22 ] of each stem [ 20 ] extends, in use, downwardly along the direction of an imaginary vertical axis A-A extending through each suspension portion [ 24 ], even though the same vertical axis does not necessarily pass through both suspension portion [ 24 ] and drip collection end portion [ 26 ]. In this regard, it is pointed out that the vertical axis A-A through the suspension portion shown in  FIG. 1  of the drawings does not pass through the drip collection end portion of that Figure, while in  FIG. 3  the vertical axis A″-A″ passes through both portions as will be further explained below. 
         [0022]    Up to this point in this disclosure it has been shown that the article processing stem of this invention as shown in  FIG. 1  comprises a body member [ 22 ] having a transport/carrier suspension portion [ 24 ] at one end, a drip collection end portion [ 26 ] at the opposite end, an intermediate portion [ 28 ] extending between the suspension portion [ 24 ] and the drip collection end portion [ 26 ], an article-mounting support portion [ 30 ] extending from the intermediate body portion [ 28 ] and an article-mounting surface [ 32 ] on the article-mounting support portion. 
         [0023]    Now, with reference to  FIG. 2  and  FIG. 3  of the drawings, it can be seen readily that the embodiments of those Figures each comprise identical elements with the corresponding elements identically numbered in each figure, the identically numbered elements of  FIG. 2  being identified for convenience by addition of a superscript single “prime” [′] and the identically numbered elements of  FIG. 3  being identified for convenience by addition of a superscript double “prime” [″]. The function and significance of these numbered elements as described herein, do not differ significantly from each other. Further, in each figure, an imaginary vertical axis through the suspension portion [ 24 ] has been identified by the letters A-A with the addition of single and double “prime” symbols in  FIGS. 2 and 3 . 
         [0024]    In  FIG. 1 , it may be noted that a lower portion [ 28   a ] of intermediate body portion [ 28 ] is substantially straight, rather than curved as in  FIGS. 2 and 3 . For the purposes of this invention, it should be understood that lower body portion [ 28   a ] in  FIG. 1  may be curved or straight, as shown, without affecting the working of the invention, subject to consideration of the orientation of surface [ 32 ] for positioning of articles relative body portion [ 28 ] as further explained herein. 
         [0025]      FIG. 4  of the drawings may now be reviewed to enhance understanding of the unique features of the invention previously described with reference to  FIGS. 1 ,  2  and  3 . In  FIG. 4  elements corresponding to  FIGS. 1 ,  2  and  3  have again been pointed out using identical reference numerals with the added identification and distinction of the triple “prime” symbol [′″]. It should be noted and understood that reference numeral  15   FIG. 4  is the only numeral that does not also appear in  FIGS. 1 ,  2  and  3 . Numeral  15  identifies a non-symmetrical article different in shape only from article  14 , previously described. That is, article  15  may be an optical lens blank or any arbitrary article of similar or related character. 
         [0026]    In  FIG. 4 , article processing stem [ 20 ′″] may be seen to be substantially identical in shape to processing stem [ 20 ] of  FIG. 1 , with the exception that drip collection end portion [ 26 ′″] is longer than end portion [ 26 ] of  FIG. 1 . This difference serves to emphasize another feature of this invention; namely, that stem [ 20 ] is dimensioned for each particular article so that the tip [ 26   a ] of each drip collection portion [ 26 ] will not be vertically higher, and preferably will be vertically lower, than the lowest edge portion [ 14   b ] of an article [ 14 ] attached to stem [ 20 ]. This aspect of the invention helps to assure that when a transport carrier is raised vertically from a treatment bath [ 60 ], the tips [ 26   a ] of stems [ 20 ] will not separate from the liquid surface of the bath [ 60 ] before the lowest point of an attached article separates from the liquid. This reduces the possibility that liquid “drips” from the tips [ 26   a ] will disturb the surface of the bath while any part of the article remains submerged. 
         [0027]      FIG. 4  serves to illustrate two further significant aspects of this invention: (1) the intermediate portion [ 28 ′″] of body member [ 22 ′″] is located vertically above drip collection portion [ 26 ′″] when the stem [ 20 ] is in use as herein described; this body portion is substantially smooth and continuous so as to direct the gravitational flow of liquid along the surface of body portion [ 22 ] downwardly toward the point [ 26   a ′″] of drip collection end portion [ 26 ′″]; and (2) article-mounting surface [ 32 ′″] is specifically dimensioned and oriented for each article attached thereto, such as [ 14 ] or [ 15 ′″], to assure that article mounting support portion [ 30 ′″] extends downwardly and away from the body of article [ 15 ′″] so that an imaginary vertical line [B-B] extending in a vertical direction downwardly from mounting surface [ 32 ′″] does not intersect any portion of an attached article. This configuration further helps to assure that liquid or other treatment material on the surface of the body [ 22 ] will tend to flow away from an attached article. 
         [0028]    Within the scope of this invention as herein disclosed, the mechanism for attaching articles [ 14 ], [ 15 ] to attachment surfaces [ 32 ] may be of any known technology and design suitable to the materials from which the articles and the stems are formed. For example for thermoplastic materials a conventional heating element may be acceptable. Suitable heating elements for this use will be familiar to those having ordinary skill in this art. Although a heating element is herein suggested, it will also be apparent to those skilled in the art, that other methods and forms of attachment may be employed, such as for example, adhesive bonding, ultrasonic welding, and mechanical embedding. 
         [0029]    Although preferred embodiments of the invention have been illustrated and described, it will be obvious to those having skill in this art that various other forms and embodiments of the invention now may be visualized, readily, by those having skill in this art, without departing substantially from the spirit and scope of the invention set forth in the accompanying claims.