Abstract:
A cleaning apparatus for a lens defining opposed top and bottom surfaces and a peripheral edge. The cleaning apparatus comprises a rotatable base having a plurality of arms pivotally connected thereto and rotatable therewith. The arms are configured to releasably engage the peripheral edge of the lens. The cleaning apparatus further comprises a means for propelling a heated medium towards at least one of the top and bottom surfaces of the lens while the lens is being spun by the rotation of the base and the arms.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    (Not Applicable)  
         STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT  
         [0002]    (Not Applicable)  
         BACKGROUND OF THE INVENTION  
         [0003]    The present invention relates generally to optical lens manufacturing devices and methodologies and, more particularly, to a steam cleaning apparatus for removing residue from an optical lens, such as an eyeglass lens.  
           [0004]    In the art of optometry, it is known that the process for grinding the prescription on an optical lens, such as an eyeglass lens, involves the initial step of affixing the lens to a chuck, a process typically referred to as “blocking”. The affixation or mounting of the lens to the chuck is typically accomplished through the use of a wax or alloy material. When wax is employed, the front surface of the lens is typically forced into direct, abutting contact with the wax material included on the chuck. The adhesion between the front surface of the lens and the wax material effectively affixes the lens to the chuck, thereby allowing the lens to be subjected to subsequent grinding and polishing operations. During the polishing operation, wax particles can break free, with such wax particles contaminating the polish and being deposited on the lens surfaces during the polishing process. Upon the completion of these operations, the lens is de-blocked, i.e., removed from the chuck. However, upon such de-blocking, the wax material typically leaves a residue on the front surface of the lens that is difficult to remove. In addition, residual polish material often remains on the lens and is itself difficult to remove. Additionally, it is known that many lenses are subjected to a coating process after being de-blocked. As will be recognized, any wax residue or polish residue remaining on the lens can cause substantial defects in such coating process, thus necessitating thorough removal of such wax or polish residue from the lens prior to any coating process being initiated.  
           [0005]    A current industry practice is to remove the wax and polish residue from the surfaces of the lens by hand. More particularly, the method involves filling a container with a cleaner, and thereafter dipping the lens into the cleaner. The cleaner is effective in removing the wax residue from the lens. However, over time, there is a tendency for a film residue to form on the top surface of the cleaner within the container. This film residue upon the cleaner subjects lenses dipped therein to contamination or re-contamination when pulled out of the cleaner after the initial dip. This susceptibility is only mitigated by frequently changing the cleaner within the container, which is costly. Moreover, the manual, hand-dipping process itself is labor intensive, time consuming, and therefore expensive. Though hand cleaning of the lens through the use of a sponge or brush is sometimes practiced as an alternative cleaning method, this process is also labor intensive, time consuming, and thus costly.  
           [0006]    The present invention addresses these deficiencies by providing an apparatus for cleaning residue remaining on a de-blocked optical lens. The apparatus, and related method of using the same, effectively decreases the time required for cleaning a lens, in addition to minimizing risks of lens contamination. These, as well as other features and advantages of the present invention, will be discussed in more detail below.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    In accordance with the present invention, there is provided a cleaning apparatus for a lens which defines opposed top and bottom surfaces and a peripheral edge. The cleaning apparatus comprises a rotatable base having a plurality of arms which are pivotally connected to the base and rotatable therewith. The arms are configured to releasably engage the peripheral edge of the lens. The cleaning apparatus further comprises a means for propelling a heated medium towards at least one of the top and bottom surfaces of the lens while the lens is being spun by the rotation of the base and the arms. Such means may comprise a steam conduit which includes a dispensing nozzle selectively positionable in a prescribed orientation relative to the lens mounted within the arms. In this regard, steam may be employed as the heated medium, with such steam optionally being mixed with a detergent.  
           [0008]    Further in accordance with the present invention, there is provided a method of cleaning a de-blocked lens having opposed top and bottom surfaces and a peripheral edge. The method comprises the initial step of releasably engaging the peripheral edge of the lens with a gripper mechanism. Thereafter, the lens is rotated, with a heated medium (e.g., steam mixed with detergent) being applied to at least one of the top and bottom surfaces of the lens while the lens is rotating. The method may further comprise the optional step of rinsing the lens with water subsequent to the completion of the steam cleaning and polishing operation. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    These, as well as other features of the present invention, will become more apparent upon reference to the drawings wherein:  
         [0010]    [0010]FIG. 1 is a top perspective view of an optical lens cleaning apparatus constructed in accordance with the present invention;  
         [0011]    [0011]FIG. 2 is a top plan view of the optical lens cleaning apparatus shown in FIG. 1; and  
         [0012]    [0012]FIG. 3 is a flow chart illustrating exemplary steps for cleaning an optical lens using the optical lens cleaning apparatus shown in FIGS. 1 and 2. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]    Referring now to the drawings wherein the showings are for purposes of illustrating preferred embodiments of the present invention only, and not for purposes of limiting the same, FIGS. 1 and 2 are perspective and top views, respectively, of an optical lens cleaning apparatus  10  constructed in accordance with the present invention. As will be discussed in more detail below, the apparatus  10  is used to remove wax and polish residue and/or other contaminants from a de-blocked optical lens  50 , thus properly preparing the lens  50  for a subsequent coating or inspection operation. The cleaning apparatus  10  is effective in removing wax, polish, fingerprints, grease, oil, and inorganic material from the lens  50 , including the front and back surfaces  50   a,    50   b  and peripheral edge  51  thereof.  
         [0014]    The cleaning apparatus  10  of the present invention comprises an annular, ring-like base  16  which defines opposed, generally planar top and bottom surfaces. In the cleaning apparatus  10 , the base  16  is rotatable, and is mounted to a bearing system to facilitate such rotation. This bearing system includes inner and outer races, and heat resistant plastic rollers with ball-bearings disposed on the inner race. The bearing assembly is driven from its outer race by a continuous drive belt  20  which operatively couples the bearing assembly to a drive motor  18 . In this regard, the activation of the drive motor  18  effectively facilitates the rotation of the base  16  due to the operative coupling of the drive motor  18  to the bearing assembly via the drive belt  20 .  
         [0015]    Disposed on the top surface of the base  16  is a gripper mechanism for maintaining the lens  50  in a prescribed orientation relative to the base  16 . The gripper mechanism comprises a plurality (and preferably three) generally L-shaped arms  12 . Each of the arms  12  includes a base portion  13  which is pivotally connected to the top surface of the base  16 . The base portion  13  of each arm  12  has a generally rectangular configuration defining opposed longitudinally and laterally extending sides. Included on the base portion  13  of each arm  12  adjacent one lateral side thereof is a weight  15 . The functionality of the weights  15  of the arms  12  will be described in more detail below.  
         [0016]    In addition to the base portion  13 , each arm  12  includes an elongate strut portion  17  which extends angularly from the base portion  13 . The strut portion  17  of each arm  12  itself has a generally L-shaped configuration, with the distal end portion thereof extending perpendicularly relative to its remainder. Attached to the distal end of the strut portion  17  of each arm  12  is a lens gripper  14 . As best seen in FIG. 2, the base portions  13  of the arms  12  are pivotally connected to the base  16  at locations such that the lens grippers  14  disposed on the distal ends of the strut portions  17  are separated from each other at equidistant intervals of approximately one hundred twenty degrees.  
         [0017]    In the cleaning apparatus  10  of the present invention, the lens grippers  14  are sized and configured to engage and thus grip the peripheral edge  51  of the lens  50  in the manner shown in FIGS. 1 and 2. Advantageously, the configuration of the lens grippers  14  minimizes the contact area between the arms  12  and the lens  50 . Though, as shown in FIGS. 1 and 2, the lens grippers  14  comprise discreet elements which are attached to respective ones of the arms  12 , those of ordinary skill in the art will recognize that the strut portions  17  of the arms  12  may be formed to include lens grippers as integral portions thereof.  
         [0018]    In order to maintain firm contact between the lens grippers  14  and the peripheral edge  51  of the lens  50 , the arms  12  and, in particular, the strut portions  17  thereof, are normally biased radially inwardly toward the axis defined by the base  16 . Such bias is facilitated by a biasing spring  22 . As shown in FIG. 1, one end of the biasing spring  22  is attached to the top surface of the base  16 , with the opposite end of the biasing spring  22  being attached to one segment of a linkage mechanism  23  which is pivotally connected to and mechanically interconnects the base portions  13  of the arms  12  to each other. The linkage mechanism  23 , which includes multiple segments interconnecting corresponding pairs of the base portions  13  of the arms  12 , is operative to facilitate the application of the biasing force exerted by the spring  22  to each of the strut portions  17  and, hence, all three lens grippers  14 .  
         [0019]    In order to facilitate the placement of the lens  50  within or between the lens grippers  14 , the arms  12  and, in particular, the strut portions  17  thereof, are rotated outwardly to facilitate the movement of the lens grippers  14  radially outwardly relative to the axis of the base  16 . The interconnection of the arms  12  to each other via the linkage mechanism  30  causes the outward rotation of a single arm  12  to facilitate the simultaneous outward rotation of the remaining two arms  12 . As will be recognized, sufficient force must be applied to one of the arms  12  as necessary to overcome the radially inwardly directed biasing force applied thereto by the biasing spring  22 . Those of ordinary skill in the art will recognize that the cleaning apparatus  10  need not necessarily include the linkage mechanism  23 , and that the arms  12  may be independent of each other. In this regard, the base portion  13  of each such arm  12  may be attached to one end of a biasing spring  22 , with the opposite end of such spring  22  being attached to the top surface of the base  16  such that a total of three biasing springs  22  are included in the cleaning apparatus  10 .  
         [0020]    The cleaning apparatus  10  of the present invention further comprises a steam conduit  24  which includes a nozzle disposed at its distal end adjacent a lens  50  held within the arms  12 . The nozzle of the steam conduit  24  is selectively, pivotally positionable relative to the lens  50 . During a cleaning operation, the lens  50  is preferably mounted within the arms  12  such that the top surface  50   a  thereof, which is normally covered with the wax residue or film, is directed upwardly away from the base  16 . The nozzle of the steam conduit  24  is preferably positioned relative to the lens  50  such that steam exiting the nozzle thereof directly impinges the top surface  50   a  of the lens  50 . It is contemplated that the nozzle of the steam conduit  24  may be positioned such that the steam propelled therefrom is applied to both the top and bottom surfaces  50   a,    50   b  of the lens  50 , though not necessarily in equal measure. In this instance, the steam exiting the nozzle of the steam conduit  24  can be used to simultaneously clean both the top and bottom surfaces  50   a,    50   b  of the lens  50 . During the cleaning operation, the lens  50  is preferably rotated via the rotation of the base  16  in the above-described manner. Advantageously, as the rotational speed of the base  16  increases, the strength of engagement between the lens grippers  14  and peripheral edge  51  of the lens  50  is likewise increased due to the action of the weights  15  disposed on the base portions  13  of the arms  12 .  
         [0021]    The cleaning of both the top and bottom surfaces  50   a,    50   b  of the lens  50  simultaneously, as opposed to separately, substantially reduces the risk of recontaminating the cleaned side of the lens  50 . The temperature of the steam applied to the lens  50  is sufficient to remove typical residue (e.g., the above-described wax residue) from the top and bottom surfaces  50   a,    50   b  of the lens  50 . To assist in the residue removal process, it is preferred that a detergent be mixed with the steam. It is contemplated that the mixture of such detergent with the steam will occur at the nozzle of the steam conduit  24 . A preferred detergent will have degreasing and surfactant properties well suited for removing common lens contaminants found in an optical laboratory. The steam conduit  24  is preferably fabricated from stainless steel, though other materials may be employed as an alternative. It is also contemplated that hot water may be used as an alternative to steam, with the water being heated to a temperature above the melting point of the residue to be removed from the top and bottom surfaces  50   a,    50   b  of the lens  50 .  
         [0022]    The cleaning apparatus  10  of the present invention may optionally include a water conduit  26  which also has a nozzle disposed at the distal end thereof and located in close proximity to the lens  50 . The water conduit  26 , like the steam conduit  24 , may be selectively rotated or pivoted to facilitate the placement of the nozzle thereof in a prescribed position relative to the lens  50 . The water conduit  26 , which is also preferably fabricated from a stainless steel material, is adapted to expel rinse water upon the lens  50  subsequent to the completion of the steam cleaning process described above. Such rinse process can be used to remove any residual detergent that may remain on the top and bottom surfaces  50   a,    50   b  or peripheral edge  51  of the lens  50 .  
         [0023]    [0023]FIG. 3 provides a flow diagram illustrating exemplary steps which may be used for cleaning and polishing the de-blocked optical lens  50  using the above-described cleaning apparatus  10 . In step  100 , the peripheral edge  51  of the lens  50  is gripped through the use of the lens grippers  14  of the arms  12 . As explained in step  102 , the lens grippers  14  are then rotated via the rotation of the base  16  by the activation of the drive motor  18 , thus in turn rotating the lens  50 . As explained in step  104 , while the lens  50  is rotating, a heated medium such as steam or hot water is directed towards one or both of the top and bottom surfaces  50   a,    50   b  of the lens  50 , thus facilitating the cleaning and polishing thereof. As explained above, detergent is preferably mixed with the steam at the nozzle of the steam conduit  24  for application to the lens  50  while the same is rotating. The spinning or rotating lens  50  may then optionally be rinsed by spraying water thereon from the nozzle of the water conduit  26 .  
         [0024]    As indicated above, the use of the steam or hot water in the cleaning and polishing operations of the present invention is operative to remove optical blocking materials, such as wax and/or other contaminants (e.g., polish), from the top and bottom surfaces  50   a,    50   b  of the lens  50 . The steam, hot water, and/or detergent is heated to a temperature above the melting point of the blocking material prior to being propelled toward the lens  50 . By gripping the peripheral edge  51  of the lens  50  with minimal contact, the contamination can be removed thoroughly through this process, with the simultaneous cleaning of both the top and bottom surfaces  50   a,    50   b  reducing the risk of re-contaminating the cleaned side, as indicated above. The non-contact method of cleaning facilitated through the use of the cleaning apparatus  10  of the present invention also reduces the risks of cross-contamination. Spent solutions are not reused, thereby further reducing the risk of re-contamination, with the use of steam making the cleaning apparatus  10  more economical to operate.  
         [0025]    Additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art. Thus, the particular combination of parts described and illustrated herein is intended to represent only certain embodiments of the present invention, and is not intended to serve as limitations of alternative devices within the spirit and scope of the invention.