Abstract:
An apparatus includes a manifold having a passageway through the manifold and a seal fitting extension. The seal fitting extension includes a shoulder portion having a metal seal ring. The apparatus also includes a pinch-off tube having a flange in sealed contact with the metal seal ring of the shoulder portion of the manifold. The apparatus could further include a backing element in contact with the flange of the pinch-off tube, where the backing element forces the flange into contact with the metal seal ring. In addition, the apparatus could include a sealing nut in contact with the backing element, where the sealing nut causes the backing element to force the flange into contact with the metal seal ring.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure is directed generally to vacuum seal technology and, in particular, to a metal-to-metal seal that utilizes a flanged pinch-off tube and related apparatus and method. 
       BACKGROUND 
       [0002]    In the operation of vacuum seal devices, it is common to connect a pinch-off tube to a fill manifold. A fill manifold typically includes a body that has portions forming a cylindrical passageway through the body of the fill manifold. The body of the fill manifold also typically has a cylindrical annular flange. 
         [0003]    Conventional techniques typically attach the pinch-off tube to the seal fitting extension of the fill manifold by welding a sealing flange onto the pinch-off tube. The welded sealing flange of the pinch-off tube is then attached to the cylindrical annular flange of the fill manifold. However, the welded sealing flange has the disadvantage that it can only be used once. Moreover, welding the sealing flange to the pinch-off tube may be relatively expensive, increasing the cost of conventional vacuum seal devices. 
       SUMMARY 
       [0004]    This disclosure provides a metal-to-metal seal that utilizes a flanged pinch-off tube and related apparatus and method. 
         [0005]    In a first embodiment, a seal assembly includes a manifold having a passageway through the manifold and a seal fitting extension. The seal fitting extension includes a shoulder portion, where the shoulder portion includes a metal seal ring on the shoulder portion. 
         [0006]    In particular embodiments, the metal seal ring includes a ring structure located circumferentially around an exit of the passageway through the manifold. The metal seal ring could have a rounded edge. 
         [0007]    In other particular embodiments, the seal assembly also includes a pinch-off tube having a flange in contact with the metal seal ring. 
         [0008]    In yet other particular embodiments, the seal assembly also includes a backing element in contact with the flange of the pinch-off tube. The backing element forces the flange into contact with the metal seal ring. The backing element may include an aperture through the backing element, where the aperture is configured to receive the pinch-off tube. 
         [0009]    In still other particular embodiments, the seal assembly also includes a sealing nut in contact with the backing element. The sealing nut causes the backing element to force the flange into contact with the metal seal ring. The sealing nut may include a first aperture configured to receive the backing element and a second aperture configured to receive the pinch-off tube. The sealing nut may also include first threads configured to engage second threads on the seal fitting extension. 
         [0010]    In a second embodiment, an apparatus includes a manifold having a passageway through the manifold and a seal fitting extension. The seal fitting extension includes a shoulder portion having a metal seal ring. The apparatus also includes a pinch-off tube having a flange in sealed contact with the metal seal ring of the shoulder portion of the manifold. 
         [0011]    In a third embodiment, a method includes providing a manifold and a pinch-off tube. The manifold includes a passageway through the manifold and a seal fitting extension, where the seal fitting extension includes a shoulder portion having a metal seal ring. The pinch-off tube includes a flange. The method also includes placing the flange in contact with the metal seal ring and forcing the flange into sealed contact with the metal seal ring. 
         [0012]    Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    For a more complete understanding of this disclosure and its advantages, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
           [0014]      FIG. 1  illustrates a perspective cross-sectional view of an example vacuum seal device according to this disclosure; 
           [0015]      FIG. 2  illustrates a cross-sectional view of a fill manifold and a pinch-off tube in the vacuum seal device according to this disclosure; 
           [0016]      FIG. 3  illustrates a more detailed cross-sectional view of the fill manifold and the pinch-off tube in the vacuum seal device according to this disclosure; and 
           [0017]      FIG. 4  illustrates an example method for forming a vacuum seal device using a fill manifold and a pinch-off tube according to this disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]      FIGS. 1 through 4  and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the invention may be implemented in any type of suitably arranged fill manifold. 
         [0019]      FIG. 1  illustrates a perspective cross-sectional view of an example vacuum seal device  100  according to this disclosure. In this example, the vacuum seal device  100  includes a fill manifold  110  and a cylindrical pinch-off tube  120 . As shown in  FIG. 1 , the fill manifold  110  includes portions that form a cylindrical passageway  130  through the body of the fill manifold  110 . The fill manifold  110  also includes portions that form a seal fitting extension  140  around one end of the cylindrical passage  130 . 
         [0020]    The seal fitting extension  140  has portions that form a shoulder  150 , which extends from an outer circumference of the seal fitting extension  140  to the edge of the cylindrical passageway  130 . As shown in  FIG. 1 , the shoulder  150  of the seal fitting extension  140  has portions that form a metal seal ring  160  around the circumference of the cylindrical passageway  130 . 
         [0021]    The cylindrical pinch-off tube  120  has portions that form a flange  170  around the end of the cylindrical pinch-off tube  120 . To form a seal, the flange  170  is seated on the seal fitting extension  140  of the fill manifold  110 . As shown in  FIG. 1 , the flange  170  of the cylindrical pinch-off tube  120  is seated on the shoulder  150  of the seal fitting extension  140  when the cylindrical pinch-off tube  120  is placed into position in alignment with the cylindrical passageway  130  of the fill manifold  110 . 
         [0022]    When flange  170  is placed on the shoulder  150  of the seal fitting extension  140 , the flange  170  rests on the metal seal ring  160  of the shoulder  150 . The metal seal ring  160  is shown in  FIG. 1  as having a rounded edge, although other embodiments of the metal seal ring  160  could also be used. The metal seal ring  160  can have any other suitable shape, such as a knife edge or other similar structure. 
         [0023]    A cylindrically shaped backing element  180  is provided that has portions forming an aperture for receiving the cylindrical pinch-off tube  120 . A cylindrically shaped sealing nut  190  is also provided that has portions forming a first cylindrical aperture for receiving the backing element  180  and a second cylindrical aperture for receiving the cylindrical pinch-off tube  120 . 
         [0024]    As shown in  FIG. 1 , the cylindrical pinch-off tube  120  is placed through the aperture of the backing element  180  and through the apertures of the sealing nut  190 . The flange  170  of the cylindrical pinch-off tube  120  can then be placed into position against the metal seal ring  160  of the shoulder  150  of the fill manifold  110 . 
         [0025]    The backing element  180  pushes the flange  170  against the metal seal ring  160 . An interior surface of the sealing nut  190  can include threads that engage threads on an exterior surface of the seal fitting extension  140 . The two sets of threads can be engaged as the sealing nut  190  rotates around the seal fitting extension  140 . As the sealing nut  190  is rotated, the advance of the sealing nut  190  causes the backing element  180  to force the flange  170  of the cylindrical pinch-off tube  120  against the metal seal ring  160  of the shoulder  150 . The force from the backing element  180  against the flange  170  causes the flange  170  to deform against the metal seal ring  160 . This causes the flange  170  to form a metal-to-metal seal with the metal seal ring  160 . 
         [0026]    When the device has been processed, the cylindrical pinch-off tube  120  is pinched to form a vacuum seal. The sealing nut  190  can be rotated in a reverse direction from the threads of the seal fitting extension  140  and removed. The backing element  180  can also be removed from the cylindrical pinch-off tube  120 , and the flange  170  of the cylindrical pinch-off tube  120  can be discarded. At this point, the fill manifold  110  can be used in a subsequent sealing operation. 
         [0027]      FIG. 2  illustrates a cross-sectional view of a fill manifold  110  and a pinch-off tube  120  in the vacuum seal device  100  according to this disclosure. In particular,  FIG. 2  illustrates how the flange  170  of the pinch-off tube  120  is seated against the metal seal ring  160  of the shoulder  150  of the seal fitting extension  140 . In this example, reference numeral  210  designates the location of the threads used to engage the sealing nut  190  to the seal fitting extension  140 . 
         [0028]      FIG. 3  illustrates a more detailed cross-sectional view of the fill manifold  110  and the pinch-off tube  120  in the vacuum seal device  100  according to this disclosure. In particular,  FIG. 3  illustrates in more detail how the flange  170  of the pinch-off tube  120  is seated against the metal seal ring  160  of the shoulder  150  of the seal fitting extension  140 . 
         [0029]      FIG. 4  illustrates an example method  400  for forming a vacuum seal device using a fill manifold and a pinch-off tube according to this disclosure. A fill manifold  110  is provided at step  410 . The fill manifold  110  includes a seal fitting extension  140  with a shoulder  150 . The shoulder  150  has portions that form a metal seal ring  160  located around a cylindrical passageway  130  through the fill manifold  110 . 
         [0030]    A pinch-off tube  120  is provided and positioned at step  420 . The pinch-off tube  120  includes a flanged end portion  170  that rests on the metal seal ring  160  of the fill manifold  110  when the pinch-off tube  120  is placed on the seal fitting extension  140  of the fill manifold  110 . 
         [0031]    A backing element  180  is provided at step  430 . The backing element  180  has portions that define a cylindrical aperture for receiving the flanged pinch-off tube  120 . 
         [0032]    A sealing nut  190  is provided at step  440 . The sealing nut  190  has portions that define a first cylindrical aperture through a first portion of the sealing nut  190  for receiving the backing element  180 . The sealing nut  190  also has portions that define a second cylindrical aperture through a second portion of the sealing nut  190  for receiving the flanged pinch-off tube  120 . 
         [0033]    The backing element  180  is placed within the sealing nut  190  at step  450 . The flanged pinch-off tube  120  is placed through the apertures of the backing element  180 , and the sealing nut  190  and the flanged end  170  of the pinch-off tube  120  are placed on the metal seal ring  160  of the seal fitting extension  140  at step  460 . Threads of the sealing nut  190  are engaged with threads of the seal fitting extension  140 , and the sealing nut  190  is rotated to cause the backing element  180  to force the metal flange  170  to deform and make a metal-to-metal seal with the metal seal ring  160  at step  470 . The pinch-off tube  120  is pinched to form a vacuum seal, and the sealing nut  190  and the backing element  180  are removed from the pinch-off tube  120  at step  480 . The fill manifold  110  is now ready to be used in a subsequent sealing operation. 
         [0034]    While  FIGS. 1 through 4  have illustrated various features of example embodiments for the present invention, various changes may be made to the figures. For example, each of the various components of the vacuum seal device  100  could have any suitable size and shape. Also, while shown as a series of steps, various steps in  FIG. 4  could overlap, occur in parallel, occur multiple times, or occur in a different order. 
         [0035]    It may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. 
         [0036]    While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of the invention, as defined by the following claims.