Abstract:
There is disclosed a plating process that involves the application of a soft metallic coating, composed of substantially pure metal or alloy, to resilient metal seals utilizing a high-volume, high-energy electro-deposition plating process. The process basically includes supporting a predetermined quantity of metallic seals at non-sealing surface locations with the metallic seals disposed in series on a conveyor having a predetermined processing path, and continuously moving the seals in series through an electro-plating stage of the processing path to electro-deposit a metallic coating on the seals using a high current density and a high chemical flow rate. The seals of this process are applicable to any application or industry where a large quantity of high vacuum/high purity seals are required and where traditional electro-deposition processes would not yield a sufficient quantity of finished parts or would not produce them at an acceptable cost.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention generally relates to a process for coating seals with a metallic plating. More specifically, the present invention relates to a high energy, high volume electro-plating process for applying a soft metallic coating to static metallic seals.  
         [0003]     2. Background Information  
         [0004]     Many different types of sealing devices exist for sealing two opposing surfaces. In particular, annular sealing rings are often used to seal opposing surfaces. These annular sealing rings are commonly made of metallic materials such as soft iron, carbon steel, stainless steel, high nickel alloy, Inconel or Nimonic alloys. Typically, conventional seals are manufactured by first cutting or punching “blank” rings of sheet metal out of metallic sheet material, and then bending each of the “blank” rings into the final desired cross-sectional shape using dies (i.e., a transfer press method). Alternatively, these annular sealing rings can be constructed by forming a band, butt welding the ends and then forming the required shape using progressive dies.  
         [0005]     These annular sealing rings can have cross-sections of various shapes. For example, a “C” seal or spring-energized “C” seal is typically an annular seal having a “C” shaped cross-section. Other types of known metallic seals have cross-sections which are parabolic, convoluted, “E” shaped, Y-shaped, omega-shaped (Ω-shaped), or the like. Some of these typical seals are designed to be pressure energized. Additionally, some of these seals are designed to be more resilient than others. In other words, different seals are designed to achieve different sealing characteristics.  
         [0006]     A coating is sometimes applied to these seals to enhance the sealing characteristics. For example, some metallic seals are often coated with a deformable material (e.g., PTFE, gold, silver, copper, and the like) in order to achieve the desired seal integrity. Typically, these metallic seals are coated using time intensive, standard electro-deposition (relatively low energy, relatively low volume) processes that are labor intensive and prohibitive to high-speed manufacturing processes. Specifically, traditional electro-plating processes use a typical current density of around 5-25 ASF (current per unit area, i.e. Amps per Square Foot). Moreover, traditional plating processes for seals are typically discontinuous, which involve submerging a batch of seals in the plating solution (with mild agitation) and holding them in the plating solution for an extended time (e.g. on the order of 100 minutes) to plate a single batch of seals. Each batch typically includes a plurality of racks with each rack containing a plurality of seals. Furthermore, the seals need to be loaded unloaded from racks before and after each batch is plated, and the seals may need to be rinsed, cleaned, etc. before and/or after the plating process. Finally, depending on the type of plating to be applied to the seals, the plating times for completing a single plating process can vary greatly.  
         [0007]     Traditionally, high sealing integrity (i.e., low leakage) seals have been used in low volume (i.e., small quantities) applications where standard electro-deposition techniques have been adequate from a cost and production rate standpoint. However, when very high production rates (i.e. production of large quantities of seals) ranging from hundreds of thousands to millions of units are desired, these traditional plating techniques are not suitable. Other plating/coating processes may also be ineffective from a cost and production rate standpoint, or suffer from other drawbacks such as a lack in sealing performance due to varying thickness or lack of uniformity of coating, etc.  
         [0008]     In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved high energy plating process for static seals that overcomes the problems in the prior art. This invention addresses these needs in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.  
       SUMMARY OF THE INVENTION  
       [0009]     One object of the present invention is to provide a plating process for reliably (consistently) depositing a soft, uniform, deformable, matte metallic coating on static metallic seals in order to ensure or enhance leakage control of the seals.  
         [0010]     Another object of the present invention is to provide a high-volume (mass production), high-energy plating process to automate application of a metallic coating to metallic seals.  
         [0011]     Yet another object of the present invention is to provide a plating process that produces seals providing a sealing integrity on the order of 1×10 −9  sccs (standard cubic centimeters per second) Helium.  
         [0012]     Yet another object of the present invention is to provide a high energy, high volume plating process for static seals at a relatively low cost per seal.  
         [0013]     Still another object of the present invention is to provide a process for applying a deformable (e.g. smearable), matte finish metallic coating on metallic seals.  
         [0014]     Yet still another object of the present invention is to provide a process that facilitates manual or fully automated insertion/removal of the seals into retention clips and/or carriers with retention clips.  
         [0015]     Yet still another object of the present invention is to provide a process that facilitates continuously moving the seals in a vertical orientation.  
         [0016]     The foregoing objects can basically be attained by providing a high energy plating process for static seals comprising supporting seals on a conveyor and moving the seals through an electro-plating stage. A predetermined quantity of metallic seals is supported at non-sealing surface locations with the metallic seals disposed in series on the conveyor. The conveyor has a predetermined processing path. The metallic seals are continuously moved on the conveyor in series through the electro-plating stage to electro-deposit a metallic coating on the metallic seals using a high current density and a high chemical flow rate. The electro plating stage is part of the predetermined processing path.  
         [0017]     These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     Referring now to the attached drawings which form a part of this original disclosure:  
         [0019]      FIG. 1  is a partial, diagrammatic elevational view illustrating a high energy plating process for coating static seals in accordance with a preferred embodiment of the present invention;  
         [0020]      FIG. 2  is a side elevational view of one of the seals coated by the process illustrated in  FIG. 1 , as viewed along a central axis in accordance with a preferred embodiment of the present invention;  
         [0021]      FIG. 3  is an enlarged partial, longitudinal cross-sectional view of the seal illustrated in  FIG. 2  as viewed along section line  3 - 3  of  FIG. 2 , with the seal installed in a joint between a pair of annular, axially facing surfaces of a pair of members that are coupled together;  
         [0022]      FIG. 4  is an enlarged, partial side elevational view of a corner portion of the seal illustrated in  FIGS. 2 and 3  identified by the circle  4  in  FIG. 2 ;  
         [0023]      FIG. 5  is a further enlarged partial, cross-sectional view of the corner portion of the seal illustrated in  FIG. 4  as viewed along section line  5 - 5  of  FIG. 4 ;  
         [0024]      FIG. 6  is an enlarged, partial side elevational view of a side portion of the seal illustrated in  FIGS. 2 and 3  identified by the circle  6  in  FIG. 2 ;  
         [0025]      FIG. 7  is a partial, cross-sectional view of the portion of the seal illustrated in  FIG. 6  as viewed along section line  7 - 7  of  FIG. 6 ;  
         [0026]      FIG. 8  is an elevational view of one of the carriers used in the process of the present invention, with the seal attachment members of the carrier in the release position;  
         [0027]      FIG. 9  is an elevational view of the carrier illustrated in  FIG. 8 , with the seal attachment members of the carrier in the retaining position;  
         [0028]      FIG. 10  is an enlarged, partial cross-sectional view of the carrier and seal illustrated in  FIGS. 8 and 9 , as seen along section line  10 - 10  of  FIG. 9 ;  
         [0029]      FIG. 11  is an elevational view of an alternate carrier usable in the process of the present invention, illustrating the sliding movement of the seal;  
         [0030]      FIG. 12  is an elevational view of the carrier and seal illustrated in  FIG. 11 , with the seal retained between the seal attachment members of the carrier;  
         [0031]      FIG. 13  is an enlarged, partial cross-sectional view of the carrier and seal illustrated in  FIGS. 11 and 12 , as seen along section line  13 - 13  of  FIG. 12 ;  
         [0032]      FIG. 14  is an elevational view of another alternate carrier usable in the process of the present invention;  
         [0033]      FIG. 15  is an elevational view of another alternate carrier usable in the process of the present invention;  
         [0034]      FIG. 16  is an elevational view of another alternate carrier usable in the process of the present invention, with the hinge attachment elements in the open position allowing removal of the seal;  
         [0035]      FIG. 17  is a cross-sectional view of the seal and carrier illustrated in  FIG. 16 , as seen along section line  17 - 17  of  FIG. 16 ;  
         [0036]      FIG. 18  is an elevational view of the seal and carrier illustrated in  FIGS. 16 and 17 , with the hinge attachment elements in the closed, retaining position; and  
         [0037]      FIG. 19  is a cross-sectional view of the seal and carrier illustrated in  FIGS. 16-18 , as seen along section line  19 - 19  of  FIG. 18 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0038]     A selected embodiment of the present invention will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following description of the embodiment of the present invention is provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.  
         [0039]     Referring initially to  FIG. 1 , a process for depositing a soft (i.e., deformable, smearable), uniform, matte metallic coating on sealing surfaces of metallic seals  10  is illustrated in accordance with a preferred embodiment of the present invention. In the simplest form, the process of the present invention is a high energy, electro-plating process that preferably includes seven steps or stages S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  in order to produce a relatively large quantity of high quality coated seals  10  in a relatively short period of time. The seals  10  are preferably moved continuously in carriers  11  that are clipped onto a conveyor  12  (e.g. a continuous belt). The carriers  11  are continuously moved through the stages S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  of the electro-plating process. Each of the carriers  11  holds a predetermined number of seals  10  (e.g. a plurality of seals  10  or a single seal  10 ). In other words, the conveyor  12  has a predetermined processing path passing through the stages S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700 .  
         [0040]     The electro-plating process of the present invention is optimized for seals  10  having the structure (i.e., handling tabs) illustrated herein. In other words, the seals  10  with the handling tabs can cooperate with certain types of carriers, as explained below in more detail. In any case, the carriers  11  of the conveyor  12  support the seals  10  at non-sealing surfaces, as also explained in more detail below. However, it will be apparent to those skilled in the art from this disclosure that the process of the present invention could be utilized with seals having various configurations as needed and/or desired. In any case, the conveyor  12  is preferably designed with a plurality of carriers  11  in order to hold a large quantity of seals  10  at non-sealing areas and to continuously move the seals  10  in an automated manner through the steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  of the electro-plating process. The structure of the seals  10 , for which the process of the present invention is optimized, will be discussed in more detail below.  
         [0041]     The step S 100  is preferably a cleaning stage of the electro-plating process, while the step S 200  is preferably an initial rinsing stage of the electro-plating process. The step S 300  is preferably an under plating stage of the electro-plating process, while the step S 400  is preferably an intermediate rinsing stage of the electro-plating process. The step S 500  is preferably a top plating stage of the electro-plating process, while the step S 600  is preferably a final rinsing stage of the electro-plating process. The step S 700  is preferably a drying stage of the electro-plating process. The steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  of the electro-plating process preferably occur in series in ascending numerical order (i.e., S 100 , then S 200 , then S 300 , and so on).  
         [0042]     The steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  are preferably separate steps that each utilizes a separate solution in order to achieve the desired effect of that step. In particular, the cleaning step S 100  utilizes a liquid cleaning solution, while the rinsing steps S 200 , S 400  and S 600  utilize liquid rinsing solutions. The under and top plating steps S 300  and S 500  utilize (liquid) electrolytic/chemical solutions, while the step S 700  is preferably a separate drying step that uses a drying gas (e.g. air) and/or heat. In other words, the electro-plating process of the present invention is preferably a “wet” process, except for the drying stage S 700 . However, it will be apparent to those skilled in the art from this disclosure that additional optional drying steps or other steps can be arranged between some or all of the steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  of the electro-plating process if needed and/or desired. Moreover, it will be apparent to those skilled in the art from this disclosure that some or all of the steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  could include several sub-steps (i.e., a plurality of steps), as explained below in more detail.  
         [0043]     Referring still to  FIG. 1 , the conveyor  12  will now be discussed in more detail. The conveyor  12  is relatively conventional, except that the conveyor  12  includes specialized clips  13  (not shown in detail) for manually attaching/removing the carriers  11  thereto/therefrom. The carriers  11  hold/move the seals  10 , as mentioned above. The carriers  11  can be designed to hold a plurality of seals  10  (e.g. a dozen seals  10 ), or a single seal  10  as needed and/or desired. The carriers  11  will be discussed in more detail below. The clips  13  attach the carriers  11  to the conveyor  12 . Conveyors such as conveyor  12  and the clips  13  are relatively well known in the manufacturing arts. Thus, the conveyor  12  and the clips  13  will not be discussed and/or illustrated in detail herein, except as related to the plating process of the seals  10  of the present invention. However, the carriers  11 , the conveyor  12  and the clips  13  are especially configured to carry out the present invention, i.e., configured to ensure that the sealing surfaces are properly treated in each step of the process. In particular, the clips  13  and the carriers  11  are arranged and configured to ensure that electrical continuity between the seals  10  and a bus bar (not shown) of the conveyor  12  is sufficient to ensure there is no occurrence of electrical arching, localized overheating or contact point deposition.  
         [0044]     The attachment of the carriers  11  to the conveyor  12  can be achieved manually or in an automated manner. Once the seals  10  are mounted in the carriers  11  and the carriers  11  are clipped to the conveyor  12  via the clips  13 , the conveyor  12  continuously moves the seals  10  through the steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  of the electro-plating process. Preferably, the speed of the conveyor  12  is programmable between about six inches per minute and about forty-eight inches per minute (i.e., between about 6″/min and about 48″/min) in a conventional manner. In the illustrated embodiment, the seals  10  are preferably manually mounted/dismounted in the carriers  11 . Moreover, in the illustrated embodiment, the carriers  11  are preferably manually clipped/unclipped to/from the clips  13  of the conveyor  12  at the station identified as A in  FIG. 1 .  
         [0045]     Preferably, the picking up and releasing of the seals  10  at the station A is a conventional manual process known in the seal art that is designed such that the conveyor  12  operates as a continuous (carousel type) conveyor. However, it will be apparent to those skilled in the art from this disclosure that the seals  10  can be automatically inserted/removed into/from the carriers  11 , and that the carriers  11  can be automatically clipped/unclipped to/from the conveyor  12  if needed and/or desired. In any case the procedure at station A is conventional in the seal art. Thus, the procedure at station A will not be discussed and/or illustrated in detail herein.  
         [0046]     Once the carriers  11  are clipped in place, the conveyor  12  is arranged and configured to continuously move the seals  10  through the steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  of the electro-plating process of the present invention. Preferably, the carriers  11  and the conveyor  12  are arranged and configured to maintain the seals  10  in the vertical orientation in series during the steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  of the electro-plating process. Specifically, the conveyor  12  is preferably substantially horizontal so that vertically oriented seals  10  can be continuously moved through the steps S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700  of the electro-plating process. However, it will be apparent to those skilled in the art from this disclosure that the seals can be moved in other orientations as needed and/or desired.  
         [0047]     Referring still to  FIG. 1 , during the cleaning step S 100 , the seals  10  are preferably continuously moved (in the vertical orientation, in series) on the conveyor  12  into a cleaning container or chamber V 100 . The cleaning chamber V 100  is arranged and configured to spray the seals  10  with liquid cleaning solution as the seals  10  move through the chamber V 100 . The liquid cleaning solution can be an acid such as HCL acid or sulfuric acid. Optionally, the cleaning solution can be electrically charged. Thus, the cleaning stage S 100  can be a chemical cleaning stage and/or an electro-cleaning stage. Optionally, the cleaning stage S 100  could include an ultrasonic cleaning stage in addition to or instead of the chemical and/or electro cleaning.  
         [0048]     Of course, it will be apparent to those skilled in the art from this disclosure that the cleaning stage S 100  could include several separate cleaning sub-stages, and could include optional rinsing stages arranged between the cleaning sub-stages as needed and/or desired. Cleaning techniques for metallic seals are well known in the art. Thus, the cleaning stage S 100  will not be discussed and/or illustrated in further detail herein. If rinsing sub-stages are utilized during the cleaning stage S 100 , each rinsing sub-stage is preferably identical to the rinsing stages S 200 , S 400  and S 600 , discussed below.  
         [0049]     After the cleaning step S 100 , the seals  10  are continuously moved (in the vertical orientation, in series) through the initial rinsing step S 200 . Specifically, the seals  10  are preferably continuously moved (in the vertical orientation, in series) on the conveyor  12  into an initial rinsing container or chamber V 200 . The initial rinsing chamber V 200  is arranged and configured to spray the seals  10  with rinsing solution as the seals  10  move through the chamber V 200 . The initial rinsing solution is preferably cold, deionized water. Preferably, the rinsing stage S 200  includes a pair of rinsing sub-stages. For example, the rinsing stage S 200  preferably includes a recirculating rinse followed by a fresh rinse. The water used in the recirculating rinse is water that has already been used during a fresh and/or a recirculating rinse.  
         [0050]     After the initial rinsing step S 200 , the seals  10  are continuously moved (in the vertical orientation, in series) through the under plating step S 300 . Specifically, the seals  10  are preferably continuously moved (in the vertical orientation, in series) on the conveyor  12  into a plating container or chamber V 300 . The plating chamber V 300  is arranged and configured to spray the seals  10  with negatively charged electrolytic/chemical solution as the seals  10  move through the chamber V 300 . Specifically, a rectifier supplies DC current in order to supply metal ions from a metal anode, which are released into the electrolytic/chemical solution. Thus, the metal ions charge the electrolytic/chemical solution and are deposited on the seals  10 , as explained below. The fundamentals of electro-plating are well known. Thus, the fundamentals of electro-plating will not be discussed and/or illustrated in detail herein, except as related to the process of the present invention.  
         [0051]     In the simplest form of the present invention, during the under plating stage S 300  a single thin metallic coating can be applied to the seals  10 . However, the under plating stage S 300  can include one, two or more “striking” under plating sub-stages to apply one, two or more thin metallic coatings to the seals  10 . If a plurality of “striking” sub-stages are utilized during the under plating stage S 300 , the seals  10  are preferably rinsed between the sub-stages. In one example of a process in accordance with the present invention, the under plating stage S 300  includes a nickel “strike” followed by a rinse and then a tin “strike.” A “strike” is a relatively short electroplating stage that applies a very thin layer of metal to enhance or promote adhesion of the over plating metal applied during step S 500 , discussed below. The “striking” acts as a surface treatment for the application of a relatively thicker metal plating during the top plating step S 500 .  
         [0052]     In any case, during each “strike” stage of the under plating step S 300 , the charged electrolytic/chemical solution is expelled through a gauntlet (i.e., a plurality of strategically placed) of nozzles (not shown) directed at the seals  10  at high velocity to achieve a high chemical flow rate as compared to standard electro-deposition processes. Of course, the chemical flow rate depends on several factors, such as the metal used for the seals  10 , the metal used for the anode, the chemical solution, temperature, current density, velocity of the electrolytic/chemical solution, etc. Preferably a current density of between about 5 ASF and about 60 ASF and a spray from the nozzles are used to electro deposit a thin metal coating on the seals  10  during the stage S 300 . Thus, a relatively low current density is used during the under plating step S 300 . A high current density is not needed during this stage because only a very thin (e.g., surface treatment) of metal needs to be electro deposited on the seals  10 . Due to the variances in deposition rates for various metals with various chemical solutions, etc., the length of the stage S 300  can be varied in order to achieve a substantially constant production rate.  
         [0053]     The “length” of the stage S 300  refers to the length of the chamber V 300 . The longer the chamber V 300 , the longer time the seals  10  will be exposed to the charged electrolytic/chemical solution from the nozzles (assuming a constant speed for the conveyor  12 ). Of course, if several striking sub-stages are used during the stage S 300 , the vessel V 300  will be divided into a corresponding number of sub-vessels for each sub-stage. In any case, preferably, the seals  10  are sprayed with the charged electrolytic/chemical solution(s) from nozzles along a predetermined length or lengths of the chamber V 300 . Adjustment of the length of the chamber V 300  (or the sub-chambers if more than one strike is desired) is the primary adjustment mechanism to adjust the under plating step S 300  for different coating/base metals, etc. However, it will be apparent to those skilled in the art from this disclosure that other variables during the stage S 300  can be slightly modified as needed and/or desired in order to achieve the desired production rate for a given seal metal, coating metal, coating thickness, etc. In any case, the process of the present invention can be utilized to achieve a substantially constant production rate for coated seals  10 , regardless of the material of the seals  10 .  
         [0054]     The electrolytic/chemical solution(s) is designed to cooperate with the anode material (e.g., nickel and/or tin) to deposit the desired metallic coating, at the desired thickness on the seals  10 . A pure metal or pure metal alloy is preferably utilized for the anode material. For example, the anode material could be tin, tin alloy, lead, gold, silver, silver alloy, nickel, copper or indium. In this embodiment, the seals  10  can be constructed of any suitable material such as the metallic materials that are well known in the art. For example, the seals  10  can be constructed of 300 Series Stainless Steel, Inconel X-750, Waspaloy, or any other material appropriate for the particular operating conditions. The precise chemical solution is not critical to the present invention. Thus, it will be apparent to those skilled in the art from this disclosure that any suitable electrolytic/chemical solution could be used during the stage S 300  as needed and/or desired. In other words, the type of chemical solution needed in order to create certain metal coatings by the process of the present invention are well known. For example, hydrochloric acid can be utilized in conjunction with nickel metal during a nickel strike.  
         [0055]     After the under plating step S 300 , the seals  10  are continuously moved (in the vertical orientation, in series) through the intermediate rinsing step S 400 . Specifically, the seals  10  are preferably continuously moved (in the vertical orientation, in series) on the conveyor  12  into an intermediate rinsing container or chamber V 400 . The intermediate rinsing chamber V 400  is arranged and configured to spray the seals  10  with rinsing solution as the seals  10  move through the chamber V 400 . The intermediate rinsing solution is preferably cold, deionized water. Preferably, the rinsing stage S 400  includes a pair of rinsing sub-stages. For example, the rinsing stage S 400  preferably includes a recirculating rinse followed by a fresh rinse. The water used in the recirculating rinse is water that has already been used during a fresh and/or a recirculating rinse.  
         [0056]     After the intermediate rinsing step S 400 , the seals  10  are continuously moved (in the vertical orientation, in series) through the top plating step S 500 . Specifically, the seals  10  are preferably continuously moved (in the vertical orientation, in series) on the conveyor  12  into a plating container or chamber V 500 . The plating chamber V 500  is arranged and configured to spray the seals  10  with charged electrolytic/chemical solution as the seals  10  move through the chamber V 500 . Specifically, a rectifier supplies DC current in order to supply metal ions from a metal anode, which are released into the electrolytic/chemical solution. Thus, the metal ions charge the electrolytic/chemical solution and are deposited on the seals  10 .  
         [0057]     The step S 500  is similar to the step S 300 . However, the step S 500  is significantly longer than the step S 300  (i.e., preferably at least ten times longer than each strike sub-stage of the stage S 300 ) and deposits significantly more of a different coating on the seals  10 , as explained below in more detail. Moreover, the charged electrolytic/chemical solution is expelled through a gauntlet (i.e., a plurality of strategically placed) of nozzles (not shown) directed at the seals  10  at high velocity to achieve a high chemical flow rate as compared to standard electro-deposition processes. Of course, the chemical flow rate depends on several factors, such as the metal used for the seals  10 , the metal used for the anode, the chemical solution, temperature, current density, velocity of the electrolytic/chemical solution, etc. Preferably, a current density of between about 200 ASF and about 1000 ASF and a high velocity spray from the nozzles are used to electro deposit a top plating metal coating on the seals  10  during the stage S 500 . Due to the variances in deposition rates for various metals with various chemical solutions, etc., the length of the stage S 500  can be varied in order to achieve a substantially constant production rate.  
         [0058]     In one example of a process in accordance with the present invention, the top plating stage S 500  applies tin plating to the seals  10 . In this process, a single nickel strike is utilized during the under plating stage S 300 , and the tin plating is applied to the nickel under plating applied during the under plating stage S 300 . Alternatively, Silver plating can be applied over a single nickel strike. In another example of a process in accordance with the present invention, the top plating stage S 500  applies a tin/lead plating to the seals  10 . In this process, a nickel strike followed by a rinse and then a tin strike should be included in the under plating stage S 300 . The tin/lead plating is then applied to the tin coating of the seals  10  using a current density of about 200 ASF during the top plating stage S 500 . Free methane sulfonic acid can be used with stannous tin and lead during such a top plating stage S 500 .  
         [0059]     The “length” of the stage S 500  refers to the length of the chamber V 500 . The longer the chamber V 500 , the longer time the seals  10  will be exposed to the charged electrolytic/chemical solution from the nozzles (assuming a constant speed for the conveyor  12 ). Preferably, the seals  10  are continuously sprayed with the charged electrolytic/chemical solution from the nozzles along the entire length of the chamber V 500 . Adjustment of the length of the chamber V 500  is the primary adjustment mechanism to adjust the top plating step S 500  for different coating/base metals, etc. However, it will be apparent to those skilled in the art from this disclosure that other variables during the stage S 500  can be slightly modified as needed and/or desired in order to achieve the desired production rate for a given seal metal, coating metal, coating thickness, etc. In any case, the process of the present invention can be utilized to achieve a substantially constant production rate for coated seals  10 , regardless of the material of the seals  10 .  
         [0060]     The electrolytic/chemical solution used during the step S 500  is designed to cooperate with the anode material to deposit the desired metallic coating, at the desired thickness on the seals  10 . A pure metal or pure metal alloy is preferably utilized for the anode material. For example, the anode material could be tin, tin alloy, lead, gold, silver, silver alloy, nickel, copper or indium. The precise chemical solution is not critical to the present invention. Thus, it will be apparent to those skilled in the art from this disclosure that any suitable electrolytic/chemical solution could be used during the stage S 500  as needed and/or desired. In other words, the type of chemical solution needed in order to create certain metal coatings by the process of the present invention are well known.  
         [0061]     After the top plating step S 500 , the seals  10  are continuously moved (in the vertical orientation, in series) through the final rinsing step S 600 . Specifically, the seals  10  are preferably continuously moved (in the vertical orientation, in series) on the conveyor  12  into a final rinsing container or chamber V 600 . The final rinsing chamber V 600  is arranged and configured to spray the seals  10  with rinsing solution as the seals  10  move through the chamber V 600 . The final rinsing solution is preferably cold, deionized water. Preferably, the rinsing stage S 600  includes a pair of rinsing sub-stages. For example, the rinsing stage S 600  preferably includes a recirculating rinse followed by a fresh rinse. The water used in the recirculating rinse is water that has already been used during a fresh and/or a recirculating rinse.  
         [0062]     After the final rinsing step S 600 , the seals  10  are continuously moved (in the vertical orientation, in series) through the drying step S 700 . Specifically, the seals  10  are preferably continuously moved (in the vertical orientation, in series) on the conveyor  12  into a drying container or chamber V 700 . The drying chamber V 700  is arranged and configured to spray the seals  10  with a drying gas such as air as the seals  10  move through the chamber V 400 . The drying chamber V 700  could also use heat in addition to or instead of the drying gas if needed and/or desired. After step S 700 , the plating process of the present invention is complete. Due to the carousel design of the conveyor  12 , the carriers with the finished, coated seals  10  are then sent back to the station A to be unloaded and to have a new batch of uncoated seals  10  loaded onto the conveyor  12 .  
         [0063]     The under plating step/stage S 300 , the intermediate rinsing step/stage S 400  and the top plating step/stage S 500  together form parts of an overall “electro-plating stage” of the predetermined processing path of the present invention. Of course, it will be apparent to those skilled in the art from this disclosure that the electroplating stage could include additional/fewer steps as needed and/or desired. In any case, the electroplating stage of the present invention preferably includes at least one plating step/stage that electro-deposits a coating metal on the seals  10  using a high current density and high chemical flow rate as described herein in accordance with the present invention.  
         [0064]     Preferably, the process of the present invention is designed such that the primary variables are speed of the conveyor  12 , seal material, anode material, electrolytic/chemical solution, and the length of the stages S 100 , S 200 , S 300 , S 400 , S 500 , S 600  and S 700 . In other words, the remaining variables of the process such as temperature, current density, electrolytic/chemical solution flow velocity, nozzle structure, etc. are preferably kept substantially constant. However, the speed of the conveyor is preferably programmed to a predetermined (i.e., substantially constant) level or speed consistent with the operations at the station A. Thus, if the desired coating thickness, coating material or seal material is changed, the length of at least the stages S 300  and/or S 500  and the electrolytic/chemical solution would preferably be changed in order to achieve the desired product at the pre-programmed speed. Thus, the process of the present invention is relatively simple.  
         [0065]     Referring now to  FIGS. 2-7 , the metallic seals  10  will be discussed in more detail. The seals  10  are identical to each other. Thus, only one of the seals  10  will be discussed and illustrated in detail herein. Because the metallic coating applied to the seals  10  is so thin, the metallic coating will not be illustrated in detail herein. In the illustrated embodiment, the metallic seal  10  is designed to be externally pressure energized to maintain a seal between a pair of members  14  and  16 . More specifically, the seal  10  is an annular seal designed to seal a pair of axially facing annular surfaces  18  and  20  of the members  14  and  16 , respectively. While the seal  10  is illustrated as being externally pressurized, it will be apparent to those skilled in the art from this disclosure that the seal  10  could be internally pressurized as needed and/or desired. Moreover, it will be apparent to those skilled in the art from this disclosure that the seals  10  could be designed as radial seals with radially facing sealing surface and/or with various cross-sectional shapes, as needed and or desired for certain sealing applications. In other words, the seals  10  illustrated herein are merely an example suitable for the plating process of the present invention.  
         [0066]     The metallic seal  10  is preferably substantially rectangular shaped with rounded corners as viewed along a central axis O. However, it will be apparent to those skilled in the art from this disclosure that the seal  10  could have various other configurations (i.e., shapes, sizes, orientations, etc.), as needed and/or desired. For example, the seal  10  could have a circular configuration or another configuration. Moreover, it will be apparent to those skilled in the art from this disclosure that the seals  10  illustrated herein may be particularly useful in industries such as the data storage, semi-conductor, automotive and power-generation industries. However, it will be apparent to those skilled in the art from this disclosure that the seals  10  could be used in other industries where high production rates and the need for high reliability sealing coverage is needed and/or desired. For example, the seal  10  could be utilized in the aerospace industry or any other industry that requires the functionality of the seal  10 .  
         [0067]     Referring still to  FIGS. 2-7 , the seal  10  basically includes a first annular leg portion  22 , a second annular leg portion  24  and an annular connecting portion  26 . The first and second leg portions  22  and  24  are connected to each other by the connecting portion  26  to form a modified C-shaped cross-sectional shape, as best seen in  FIGS. 3, 5  and  7 . Specifically, the second leg portion  24  includes an annular flange  28  with a plurality of tabs  30  extending radially from the flange  28  relative to the central axis O in order to form the modified C-shaped cross-sectional shape.  
         [0068]     The tabs  30  are arranged at the rounded corners of the rectangular shaped seal  10 . The tabs  30  project further in a radial direction than adjacent parts of annular flange  28 . The tabs  30  can be used to handle the seals  10  at the station A, to move the seals  10  on the conveyor  12  and/or during installation of the seals  10 . Specifically, modified carriers can cooperate with the tabs  30  to hold the tabs  30  (i.e., at non-sealing surfaces of the seals  10 ), as discussed below. In the illustrated embodiment, the seals  10  can be handled manually at the station A via the tabs  30 . However, it will be apparent to those skilled in the art from this disclosure that the handling of the seals  10  (i.e., at the tabs  30 ) can be fully automated to automatically pick-up and drop off the seals  10  at the station A, if needed and/or desired.  
         [0069]     The leg portions  22  and  24 , the connecting portion  26  and the flange  28  are all concentric about the central axis O of the seal  10 . Thus, the leg portions  22  and  24 , the connecting portion  26  and the flange  28  all extend around the central axis O of the seal  10 . The tabs  30  are circumferentially spaced around the seal  10 , while the flange  28  is continuous around the circumference of the seal  10 . Due to the arrangement of the flange  28  and the tabs  30 , a transverse center plane P divides the seal  10  into two asymmetrical halves. The center plane P passes through the central axis O and is preferably substantially perpendicular to the central axis O. The structure of the flange  28  and the tabs  30  will be discussed in more detail below.  
         [0070]     As best seen in  FIG. 7 , the central annular portion  26  includes a first end  32 , a second end  34 , an outer convex connecting surface  36  and an inner concave connecting surface  38 . The outer and inner connecting surfaces  36  and  38  are curved surfaces. The outer and inner connecting surfaces  36  and  38  extend between the first and second ends  32  and  34  of the central annular portion  26 . The first leg portion  22  extends from the first end  32  of the central annular portion  26 , while the second leg portion  24  extends from the second end  34  of the central annular portion  26 . The carriers  11  preferably contact the curved inner connecting surface  38 , as explained below in more detail.  
         [0071]     The first annular leg portion  22  includes an annular first free end  42 , a first annular convex outer sealing surface  44  and a first concave interior surface  46 . The first sealing surface  44  and the first interior surface  46  are curved surfaces. The first sealing surface  44  extends from the first free end  42  of the first annular leg portion  22  to the first end  32  of the central annular portion  26  (i.e., to the outer connecting surface  36 ). The first interior surface  46  also extends from the first free end  42  of the first annular leg portion  22  to the first end  32  of the central annular portion  26  (i.e., to the inner connecting surface  36 ). The first sealing surface  44  lies in a first sealing plane S 1  that is substantially parallel to the center plane P of the seal  10 . In particular, a first sealing line L 1  of the first sealing surface  44  lies in the first sealing plane S 1 .  
         [0072]     The second annular leg portion  24  includes an annular second free end  52 , a second annular convex outer sealing surface  54  and a second concave interior surface  56 . The second sealing surface  54  and the second interior surface  56  are curved surfaces. The second free end  52  includes the annular flange  28  and the tabs  30 . The second sealing surface  54  extends from the second free end  52  of the second annular leg portion  24  to the second end  34  of the central annular portion  26  (i.e., from the annular flange  28  to the outer connecting surface  36 ). The second sealing surface  54  lies in a second sealing plane S 2  that is substantially parallel to the center plane P of the seal  10 . In particular, a second sealing line L 2  of the second sealing surface  54  lies in the second sealing plane S 2 .  
         [0073]     If the seal  10  is compressed between the annular surfaces  18  and  20  of the members  14  and  16  and/or when the seal  10  is pressure energized, a pair of conventional sealing dams (not shown) are formed that lie in the first and second sealing planes S 1  and S 2 . Thus, the first and second sealing planes S 1  and S 2  are preferably substantially parallel to each other.  
         [0074]     The annular flange  28  basically includes an annular outer flat surface  62  and an annular inner flat surface  64  with an annular free edge of the second free end  52  extending therebetween. The outer and inner flat surfaces  62  and  64  of the annular flange  28  are preferably substantially parallel to each other and substantially parallel to the center plane P. Moreover, the outer and inner flat surfaces  62  and  64  of the annular flange  28  are preferably offset from the second sealing plane S 2  in the axial direction toward the first sealing plane S 1 . In this embodiment, the annular flange  28  of the second free end  52  extends in a radial direction away from central annular portion  26  at least as far as the first free end  42  of the first leg portion  22 . More specifically, the annular flange  28  with the tabs  30  preferably extends in a radial direction away from central annular portion  26  beyond the first free end  42  of the first leg portion  22  such that the annular free edge of the second free end  52  is located completely radially beyond the first free end  42  of the first leg portion  22 , as best seen in  FIGS. 3, 4 ,  6  and  7 .  
         [0075]     The second free end  52  extends outwardly in the radial direction relative to the remainder of the annular flange  28  in order to form the tabs  30 . In other words, the outer and inner flat surfaces  62  and  64  (i.e., at the tabs  30 ) of the flange  28  extend radially beyond the adjacent parts of the annular flange  28 . Thus, the tabs  30  preferably extend radially further than adjacent parts of the entire seal  10 . The seal  10  preferably has a constant cross-sectional shape around its periphery, except at the corners where the tabs  30  are located.  
         [0076]     The tabs  30  preferably have identical overall shapes as seen in  FIG. 2 . Moreover, the tabs  30  are preferably peripherally spaced from each other such that one of the tabs  30  is located at each corner portion. Optionally, one or more of the tabs  30  can have an opening or slot formed therein to facilitate manual or automated handling. Of course, it will be apparent to those skilled in the art from this disclosure that the tabs  30  can have other configurations and could be different from each other as needed and/or desired. In any case, the tabs  30  are preferably arranged and configured to facilitate the process of the present invention when certain carriers are desired, providing an area to contact with the seals  10  at non-sealing areas (surfaces).  
         [0077]     While the process of the present invention is optimized with seals  10  having the handling tabs  30 , it will be apparent to those skilled in the art from this disclosure that the process of the present invention can be used with seals absent handling tabs such as conventional c-seals or seals having other cross-sectional shapes. In such arrangements, the carriers  11  should be arranged and configured to handle non-sealing surfaces of the seals (i.e., other than the tabs  30 ). For example, if the seals  10  illustrated herein did not have the tabs  30 , the carriers  11  should be arranged and configured to hold the seals  10  on the internal curved surfaces  38 ,  46  and/or  56 , or at any other non-sealing surface(s).  
         [0078]     The seal  10  performs the sealing function between the members  14  and  16  in a conventional manner, i.e., in a manner substantially identical to conventional C-seals on the market. In other words, the manner in which the first and second sealing surfaces  44  and  54  form a seal between the annular surfaces  18  and  20  of the members  14  and  16 , respectively, is conventional. Thus, the manner in which the seal  10  seals will not be discussed and/or illustrated in details herein. However, the seal  10  is processed in high volume (mass produced) with the coating to enhance or ensure the sealing function will be consistently carried out to the desired level of reliability.  
         [0079]     Referring now to  FIGS. 8-10 , the carriers  11  will now be explained in more detail. The carriers  11  are identical to each other. Thus, only one of the carriers  11  will be discussed and illustrated in detail herein. Each carrier  11  can be designed to carry/hold a single seal  10  or a plurality of seals  10 . The carrier  11  basically includes a conveyor attachment portion  70  and at least a pair of seal attachment members  72 . Each of the pair of attachment members  72  includes a projection  74  designed to contact the curved interior of the seal  10 . Thus, the carrier  11  does not utilize the tabs  30 . The attachment members  72  are arranged and configured to move together and hold the seals  10  therebetween, and to move apart to release the seals  10 . The conveyor attachment portion  70  includes a projecting section  76  and a transverse section  78 . The projecting section  76  is clipped to the conveyor  12  via one of the clips  13  in a conventional manner.  
         [0080]     If the carrier  11  is designed to hold a single seal  10 , the carrier  11  should have a single, flat conveyor attachment portion  70  with a single projecting section  76  and two seal attachment members  72  movably coupled to the transverse section  78 . However, if the carrier  11  is designed to hold a plurality of seals  10 , the carrier  1  should have a number of transverse sections  78  corresponding to the number of seals  10  that will be coupled thereto, with a pair of the seal attachment portions  72  coupled to each transverse section  78 . The transverse sections  78  should be fixedly coupled together in such an arrangement. Moreover, in such an arrangement, each carrier  11  should have at least two projecting sections  76  extending from the transverse sections  78  that are coupled together. Whether the carriers  11  hold a single seal  10  or a plurality of seals  10  is not critical to the process of the present invention.  
       Alternate Carriers  
       [0081]     Referring to  FIGS. 11-13 , an alternate carrier  211  is illustrated for use in the process of the present invention. While only one carrier  211  is illustrated herein, it will be apparent to those skilled in the art that a plurality of carriers  211  would be used in the process of the present invention. Each carrier  211  can be designed to carry/hold a single seal  10  or a plurality of seals  10 . The carrier  211  basically includes a conveyor attachment portion  270  and at least a pair of seal attachment members  272 . Each of the pair of attachment members  272  includes a projection  274  designed to contact the curved interior of the seal  10 . Thus, the carrier  211  does not utilize the tabs  30 . The attachment members  272  are arranged and configured to hold the seals  10  therebetween. In particular, the projections  274  are preferably spaced a slightly smaller distance from each other than the corresponding dimension of the seals  10  in order to frictionally retain the seals  10  when they are slid in between the attachment members  272 . The conveyor attachment portion  270  includes a projecting section  276  and a transverse section  278 . The projecting section  276  is clipped to the conveyor  12  via one of the clips  13  in a conventional manner.  
         [0082]     If the carrier  211  is designed to hold a single seal  10 , the carrier  211  should have a single, flat conveyor attachment portion  270  with a single projecting section  276  and two seals attachment members  272  fixedly coupled to the transverse section  278 . However, if the carrier  211  is designed to hold a plurality of seals  10 , the carrier  211  should have a number of transverse sections  278  corresponding to the number of seals  10  that will be coupled thereto, with a pair of the seal attachment portions  272  fixedly coupled to each transverse section  278 . The transverse sections  278  should be fixedly coupled together in such an arrangement. Moreover, in such an arrangement, each carrier  211  should have at least two projecting sections  276  extending from the transverse sections  278  that are coupled together. Whether the carriers  211  hold a single seal  10  or a plurality of seals  10  is not critical to the process of the present invention.  
         [0083]     Referring to  FIG. 14 , an alternate carrier  311  is illustrated for use in the process of the present invention. While only one carrier  311  is illustrated herein, it will be apparent to those skilled in the art that a plurality of carriers  311  would be used in the process of the present invention. The carrier  311  is formed as excess sheet material coupled to the tabs  30  of the seals  10  by narrow sections  370 . In other words, the carrier  311  is integrally formed with one of the seals  10 . The excess sheet material remains from the initial manufacturing of the uncoated seals  10 . The narrow sections  370  are preferably arranged and configured to be broken off from the tabs  30  after the plating process of the present invention.  
         [0084]     Referring to  FIG. 15 , an alternate carrier  411  is illustrated for use in the process of the present invention. While only one carrier  411  is illustrated herein, it will be apparent to those skilled in the art that a plurality of carriers  411  would be used in the process of the present invention. The carrier  411  is formed as excess sheet material coupled to one of the tabs  30  of the seal  10  by narrow sections  470 . In other words, the carrier  411  is integrally formed with one of the seals  10 . The excess sheet material remains from the initial manufacturing of the uncoated seals  10 . The narrow sections  470  are preferably arranged and configured to be broken off from the tab  30  after the plating process of the present invention.  
         [0085]     Referring now to  FIGS. 16-19 , an alternate carrier  511  is illustrated in accordance with the present invention. While only one carrier  511  is illustrated herein, it will be apparent to those skilled in the art that a plurality of carriers  511  would be used in the process of the present invention. Each carrier  511  can be designed to carry/hold a single seal  10  or a plurality of seals  10 . The carrier  511  basically includes a conveyor attachment portion  570  and at least a pair of seal attachment members  572 . Each of the pair of attachment members  572  includes a pair of hinged seal attachment elements  574  designed to hold a respective pair of the tabs  30  of the seal  10 . Thus, the carrier  511  does utilize the tabs  30 . The hinged attachment elements  574  are arranged and configured to hold the seals  10  therebetween (i.e., the tabs  30 ) in one position and to release the tabs  30  when moved to another position as seen in  FIGS. 17 and 19 . The conveyor attachment portion  570  includes a projecting section  576  and a transverse section  578 . The projecting section  576  is clipped to the conveyor  12  via one of the clips  13  in a conventional manner.  
         [0086]     If the carrier  511  is designed to hold a single seal  10 , the carrier  511  should have a single, flat conveyor attachment portion  570  with a single projecting section  576  and two seals attachment members  572  fixedly coupled to the transverse section  578 . However, if the carrier  511  is designed to hold a plurality of seals  10 , the carrier  511  should have a number of transverse sections  578  corresponding to the number of seals  10  that will be coupled thereto, with a pair of the seal attachment portions  572  fixedly coupled to each transverse section  578 . The transverse sections  578  should be fixedly coupled together in such an arrangement. Moreover, in such an arrangement, each carrier  511  should have at least two projecting sections  576  extending from the transverse section  578  that are coupled together. Whether the carriers  511  hold a single seal  10  or a plurality of seals  10  is not critical to the process of the present invention.  
         [0087]     The terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.  
         [0088]     While only a selected embodiment has been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, the present invention could also be applied to circular seals also, i.e., a circular seal with or without tabs and/or a flange. Furthermore, the foregoing description of the embodiment according to the present invention is provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. Thus, the scope of the invention is not limited to the disclosed embodiment.