Abstract:
A coupling system, comprising: a first bellows element; a fluid handling component; and a coupling assembly releasably connecting the first bellows element to the fluid handling component for maintaining a secure connection between the first bellows element and the fluid handling component. The coupling assembly comprises a first flange attached to the first bellows element and a second flange attached to the fluid handling component, the first and second flanges alignable with each other to form a locking space; a locking member sized to fill the locking space; and a sealing structure positioned between the first bellows element and the fluid handling component to form a seal proximate the effective diameter of the first bellows element. A kit and a method for connecting a bellows element to a fluid handling component are also disclosed.

Description:
A portion of the disclosure of this patent document contains material that may be subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
     BACKGROUND OF THE INVENTION 
     Metal bellows have been used for many years in various fields of application. Metal bellows are valuable to the following areas of industry: altitude sensors, fuel control systems and other aircraft systems; spacecraft engine and electronic system applications; vacuum and semiconductor systems; medical applications such as angioplasty pumps; petrochemical valve applications; industrial sealing and industrial control systems; high voltage switchgear applications; valve seal systems; water hammer arrestor systems; diesel engines; and laboratory equipment systems. As a hermetically sealed, totally metallic flexible sealing instrumentality, metal bellows are very valuable in any system that requires strict environmental control, and especially in systems requiring high and ultra-high vacuum operational environments. One common incarnation of metal bellows, called “edge-welded” bellows, has been used successfully in all of these fields. 
     However, edge-welded bellows have historically been custom-manufactured to a particular application. Custom engineering an edge-welded bellows is a very time-consuming and expensive process, and the industries and applications in which such bellows are used often place time demands upon the maker of the bellows that interfere with the development cycles of the applications even in the best case scenario. In fact, custom-engineering a bellows has become a bottleneck item in many of these applications. Another problem posed by custom-engineering bellows has been that when such bellows are eventually made, the bellows is typically installed by welding the bellows in place in the application. Welding the bellows into the application becomes a problem when the bellows need to be replaced. Some bellows manufacturers have tried to manufacture off-the-shelf bellows that could be purchased and installed by their customers, but such bellows often require couplings that consume excessive space in their applications. This is a problem since in most such cases, bellows operate in a limited space at best. 
     What is needed, then, is a modular bellows system that allows for bellows to be manufactured in various standard sizes to be purchased and installed in an application quickly and with a high-quality, low-space-consuming seal, while at the same time providing a modular bellows that can be replaced quickly and easily by the end user of the bellows without undue expense of time and resources. 
     SUMMARY OF THE INVENTION 
     The present invention generally relates to a modular bellows system. More particularly, the present invention relates to a modular bellows system for releasably coupling a bellows to other system components. The system has the following basic structure: a pair of flanges that releasably mate together to form the coupling, a sealing structure sandwiched between the flanges to create a quality seal, and a locking member for holding the pair of flanges together to maintain the integrity of the seal. One of the flanges will normally be fixed to a bellows, and the other flange will typically be fixed to a fluid handling component such as a standard vacuum component or a second bellows. 
     Accordingly, it is an object of the present invention to provide a bellows coupling system that allows the bellows to perform as a high-quality component of a system. 
     It is a further object of the invention to provide a bellows coupling system that preserves a high-integrity seal between a bellows and other system components. 
     It is a further object of the invention to provide a bellows coupling system that may be assembled quickly. 
     It is a further object of the invention to provide a bellows coupling system that is modular. 
     It is a further object of the invention to provide a bellows coupling system that may be uncoupled quickly. 
     It is a further object of the invention to provide a bellows coupling system that is pre-engineered. 
     It is a further object of the invention to provide a bellows coupling system that does not require welding of the coupling to form a seal. 
     In addition to the foregoing, further objects, features, and advantages of the present invention should become more readily apparent to those skilled in the art upon a reading of the following detailed description in conjunction with the drawings, wherein are shown and described illustrated embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a standard edge-welded bellows. 
         FIG. 2  is a plan view of an embodiment of a flange used in the coupling system of the invention. 
         FIG. 3  is an exploded plan view of an embodiment of the coupling system of the invention. 
         FIG. 4  is a perspective view of the coupling system of the invention shown in  FIG. 3 . 
         FIG. 5  is a perspective view of the coupling system of the invention shown in  FIGS. 3 and 4 . 
         FIG. 6  is a partial cross-sectional plan view of the coupling system of the invention shown in  FIG. 5 . 
         FIG. 7  is a cross-sectional plan view of an edge-welded bellows fitted at either end with the flange of  FIG. 2 . 
         FIG. 8  is a block diagram showing how  FIGS. 8A and 8B  fit together. 
         FIG. 8A  is a plan side view of a first edge-welded bellows connected at one end to a first type of standard vacuum system component and at a second end to a second edge-welded bellows, both connections being made using the coupling system of  FIGS. 3–6 . 
         FIG. 8B  is a plan view of the second edge-welded bellows of  FIG. 8A  connected to a second type of standard vacuum system component using the coupling system of  FIGS. 3–6 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , a standard edge-welded bellows  10  (also referred to as a “bellows capsule” in the literature and as a “bellows element” herein) is shown as a flexible, hollow cylindrical metal structure made of a number of convolutions  11 . A type of metal normally used in such bellows is heat treated alloy 350 stainless steel. Convolutions  11  are specifically designed and made to provide for alternate expansion and contraction in a manner that is well known in the art. The bellows may be of any dimensions suitable for the application in which the bellows may be used. Variables of interest in making bellows include such conventional parameters as fatigue life, size, spring rate, operating force, and bellows effective area. The ends of bellows  10  are adapted to be connected to any of a variety of standard system components. As mentioned above, such connections are normally made by welding, or, in the case of formed bellows, by brazing, or soldering in the prior art. 
     Referring to  FIG. 2 , a flange  20  is shown, having a number of fingers  21  extending therefrom, separated by spaces  22 . In the preferred embodiment, flange  20  is an essential element that will allow bellows  10  to be coupled to other system components. Flange  20  is designed to be a hermaphroditic connector; a pair of flanges  20  are mated by merely aligning the fingers  21  of a first flange with the spaces  22  of a second flange, then interlocking the flanges  20  together. In this manner, only one type of connector is required to be made for all couplings. 
     Referring to  FIG. 3 , the coupling assembly  30  of the invention is shown, with a pair of opposed flanges  20  being oriented such that they may be interlocked together in the manner described above relating to  FIG. 2 . It can be seen in plan view that flanges  20  are not planar; rather, flanges  20  have some depth to allow for the interlocking of fingers  21 , as well as to provide a space for sealing the coupling. A sealing structure  31  such as a ring made of an elastomer or other resilient material is placed or sandwiched between flanges  20  to provide a high-integrity seal. In a preferred embodiment, flanges  20  provide a space for sealing structure  31  that is approximately radially halfway between the inner diameter and the outer diameter of flanges  20 . This halfway point is referred to as the “effective diameter”, a term referring to a point of neutral balance for the bellows. Placing sealing structure at a point other than the effective diameter may cause the coupling to fail. Further, the space provided by flanges  20  which is occupied by sealing structure  31  is somewhat thinner than sealing structure  31  so that as flanges  20  are mated, sealing structure  31  must be flattened slightly to mate flanges  20 . Flanges  20  should be forced toward each other so that the fingers  21  interlock to form a locking groove that runs substantially the entire outer circumference of flanges  20 . As the locking groove is manifested, a locking ring  32  made of an incomplete circle of material may be placed in the locking groove by opening locking ring  32 , wrapped around the perimeter of coupling assembly  30 , and then pressed into the locking groove to maintain the mated connection of flanges  20 . In a preferred embodiment, locking ring  32  is made from a metal such as heat-treated stainless steel. In this manner, sealing structure  31  and locking ring  32  provide opposing forces that will maintain the desired seal of the coupling. 
     Referring to  FIG. 4 , an exploded perspective view of  FIG. 3  shows that a pair of flanges  20  have an area defined within for holding sealing structure  31 , while locking ring  32  is positioned to be placed into a groove formed by fingers  21  as flanges  20  are mated together (called a “locking groove”). Referring to  FIG. 5 , the coupling system of the invention is shown with flanges  20  being mated together, each flange  20  having fingers  21  that interlock with the fingers  21  of the other flange  20 , and locking ring  32  placed into a locking groove  51  defined in the outer circumference of mated flanges  20  to maintain a proper seal. In a preferred embodiment, coupling assembly  30  is designed to withstand a pressure differential of 3 to 4 atmospheres, although a typical operational differential will be closer to 1 atmosphere. Coupling assembly  30  may be uncoupled by simply removing locking ring  32  and unmating flanges  20 . After unmating flanges  20 , sealing structure  31  may be removed or replaced. 
     Referring to  FIG. 6 , the coupling system of the invention is shown in partial cross-sectional plan view, the partial cross-section being along a line A—A as shown in  FIG. 5 . It can be seen in  FIG. 6  that in coupling assembly  30 , flanges  20  are mated together as mirror images of each other, with fingers  21  being offset from each other so that each finger  21  fits into a space  22  in the opposing flange  20 . A sealing chamber  61  is defined by the inner contours of flanges  20  and inhabited by a sealing structure  31 . Flanges  20  press against sealing structure  31  to create a high-integrity seal in coupling assembly  30 . The mating of flanges  20  defines locking groove  51  between fingers  21 , and an attachment mechanism or locking member such as locking ring  32  occupies locking groove  51  and provides a structure to maintain the high-integrity seal in coupling assembly  30 . 
     Referring to  FIG. 7 , a bellows  10  is shown in cross-sectional plan view with a flange  20  fixed to either end by welding, or comparable fixing method. So arranged, bellows  10  is prepared to be incorporated in any application as desired. Bellows  10  may be of any size, or of one of various standard sizes, as needed to fit the particular application of interest. Perhaps the least important of the dimensions of bellows  10  is the length of bellows  10 . The modular nature of the invention, and more particularly the thinness of the coupling assembly of the invention, allow for the combination of more than one bellows in an efficient manner to achieve desired bellows length without resorting to the costly and slow custom manufactured bellows of the prior art. 
     Installation of the system of the invention may be performed in any of a number of ways depending upon the application, but common features of the system of the invention will be that the releasable high-integrity seal occupying a minimum amount of space will allow a bellows to be releasably coupled to any standard vacuum component that would be required. Referring to  FIG. 8 ,  FIGS. 8A and 8B  may be combined as shown to demonstrate the common couplings that may be achieved by employing the system of the invention. 
     Referring to  FIG. 8A , a first bellows element  10  is coupled at one end to a first type of standard vacuum component, called a clamp flange  81 , using the coupling assembly  30  of the invention. The other end of first bellows element  10  is coupled to a second bellows element  82 , also using the coupling assembly  30  of the invention. Referring to  FIG. 8B , second bellows element  82  continues and terminates at a third coupling assembly  30 , which connects second bellows element  82  to a second type of standard vacuum component called a ConFlat®  83 . Each of clamp flange  81 , second bellows  82 , ConFlat®  83 , and any other type of object to be connected to first bellows element  10  in any application described herein may be functionally termed a “fluid handling component”, any of which may be releasably coupled to first bellows element  10  in a time-, space-, and cost-efficient manner. 
     The system of the invention could alternatively be described as a kit including the following kit components: a first flange; a second flange; an elastomeric seal; and a releasable flange lock retainer. The first flange and the second flange functionally correspond to flanges  20  described above. The elastomeric seal functionally corresponds to sealing structure  31 . The releasable flange lock retainer functionally corresponds to locking ring  32 . Other components could be added to the kit, such as one or more bellows elements  10 ; additional flanges, elastomeric seals, or releasable flange lock retainers; or further fluid handling components as desired. 
     The invention could alternatively be described by the following method. First, a first flange and a second flange are provided, the first flange and the second flange being able to be locked together. Next, the first flange is fixed to a bellows and the second flange is fixed to a fluid handling component in the manner described above. A sealing structure is positioned between the first flange and the second flange. The first flange and the second flange are mated together with the sealing structure in between to form a seal between the first flange, the sealing structure, and the second flange. The outer portions of the first flange and the second flange have interlocking fingers defining a locking groove in the manner described above. Finally, a flange lock retainer is inserted into the locking groove to maintain the seal formed by the mating step. The flange lock retainer may be removed from the locking groove and the flanges may be unmated from each other at any time without damaging the system. 
     Thus, although there have been described particular embodiments of the present invention of a new and useful “Coupling System, Kit, and Method”, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.