Abstract:
A spring seal includes a first substantially flat spring strip element having a plurality of slanted arms and associated notches, and a second substantially flat spring strip element having a plurality of slanted arms and associated notches oriented oppositely to the slanted arms and notches of the first substantially flat spring strip element. The first and second spring strip elements are superimposed onto each other with their oppositely oriented slanted arms forming a substantially criss-cross configuration. The criss-crossed spring arms are bent at each end and configured to define a longitudinal axis. The bent arms are folded about the longitudinal axis to form a resilient seal of enhanced strength and durability suitable for insertion into a mechanical seal jacket.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This patent application is a continuation-in-part of pending utility patent application Ser. No. 10/853,852, filed May 24, 2004, entitled “Multi Spring Ring,” published on Feb. 16, 2006 under Pub. No. US 2006/0033251 A1, which is incorporated herein in its entirety by reference. 
     
    
     COPYRIGHT NOTICE  
       [0002]     Portions of the disclosure of this patent document may contain material that is subject to copyright and/or mask work protection. The copyright and/or mask work owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright and/or mask work rights whatsoever.  
       BACKGROUND  
       [0003]     Some mechanical sealing devices contain a deformable cover or jacket element typically made of elastomeric and or Teflon materials and a metallic resilient spring energizer which is readily inserted into the jacket and locked in place. A number of different configurations of mechanical spring seals are known, as disclosed, for example, in my prior U.S. Pat. Nos. 4,133,542 and 4,508,356. These types of seals are used in a variety of applications which require different types of spring energizers. Typically, all existing jacket elements are manufactured for only one specific type of energizer and if one needs to change any of the springs one would need to manufacture a completely new jacket or cover which increases manufacturing and operational costs. Also, these types of seals are increasingly being used in a variety of applications under consistently changing environments where one type of expander cannot perform as well as another when working conditions change at which one type of internal spring element has to be replaced with another type.  
         [0004]     It would be desirable to simply replace one spring element with another on site without having to manufacture a new jacket or cover, as commonly practiced.  
       SUMMARY  
       [0005]     Some embodiments disclosed herein are generally directed to a resilient spring and an associated spring seal.  
         [0006]     In accordance with one aspect of the invention, the resilient spring comprises a first substantially flat spring strip element including a plurality of slanted arms and associated notches, and a second substantially flat spring strip element including a plurality of slanted arms and associated notches oriented oppositely to the slanted arms and notches of the first substantially flat spring strip element. The first and second spring strip elements are superimposed onto each other in a substantially lattice configuration. The lattice configuration enhances the overall spring resiliency, strength and durability.  
         [0007]     In accordance with another aspect of the invention, the resilient spring comprises a first substantially flat spring strip element including a plurality of slanted arms and associated notches, and a second substantially flat spring strip element including a plurality of slanted arms and associated notches oriented oppositely to the slanted arms and notches of the first substantially flat spring strip element. The first and second spring strip elements are superimposed onto each other with their respective oppositely oriented slanted arms forming a substantially criss-cross configuration. The criss-crossed spring arms are bent at each end to enhance the overall spring resiliency, strength and durability.  
         [0008]     In accordance with still another aspect of the invention, the spring seal comprises a first substantially flat spring strip element having a plurality of slanted arms and associated notches, and a second substantially flat spring strip element having a plurality of slanted arms and associated notches oriented oppositely to the slanted arms and notches of the first substantially flat spring strip element. The first and second spring strip elements are superimposed onto each other with their oppositely oriented slanted arms forming a substantially criss-cross configuration. The criss-crossed spring arms are bent at each end and configured to define a longitudinal axis. The bent arms are folded about the longitudinal axis to form a resilient seal of enhanced strength and durability suitable for insertion into a mechanical seal jacket.  
         [0009]     In accordance with yet another aspect of the invention, the spring seal comprises a substantially flat spring strip element including a plurality of slanted arms and associated notches. The slanted arms are bent at opposite ends and configured to define a longitudinal axis. The bent arms are folded about the longitudinal axis to form a resilient seal of enhanced strength and durability suitable for insertion into a mechanical seal jacket.  
         [0010]     These and other aspects of the invention will become apparent from a review of the accompanying drawings and the following detailed description of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The invention is generally shown by way of reference to the accompanying drawings in which:  
         [0012]      FIG. 1  is a cross-sectional view of a typical mechanical spring seal jacket;.  
         [0013]      FIG. 2  is a plan view of a flat spring strip element configured in accordance with one exemplary embodiment of the present invention;  
         [0014]      FIG. 3  is a front elevation of a spring formed in accordance with another exemplary embodiment of the present invention;  
         [0015]      FIG. 4  is a cross-sectional view of a spring seal formed in accordance with yet another exemplary embodiment of the present invention;  
         [0016]      FIG. 5  is a cross-sectional spring seal assembly view showing the seal jacket of  FIG. 1  containing a typical spring element of canted coil;  
         [0017]      FIG. 6  is a cross-sectional spring seal assembly view showing a typical flat ribbon coil spring fitted inside the seal jacket of  FIG. 1 ;  
         [0018]      FIG. 7  is a cross-sectional spring seal assembly view showing a typical modified “C” spring fitted inside the seal jacket of  FIG. 1 ;  
         [0019]      FIG. 8  is a cross-sectional spring seal assembly view showing a typical straight cantilever U/V type spring fitted inside the seal jacket of  FIG. 1 ;  
         [0020]      FIG. 9  is a cross-sectional spring seal assembly view showing a typical elastomeric O-ring inserted inside the seal jacket of  FIG. 1 ;  
         [0021]      FIG. 10  is a cross-sectional view showing a spring seal assembly constructed in accordance with the present invention;  
         [0022]      FIG. 11  is a plan view of a flat spring formed in accordance with an alternative embodiment of the present invention;  
         [0023]      FIG. 12  is a front elevation of a spring formed in accordance with another alternative embodiment of the present invention;  
         [0024]      FIG. 13  is a cross-sectional view of an enhanced spring seal formed in accordance with still another alternative embodiment of the present invention;  
         [0025]      FIG. 14  is a cross-sectional view showing another spring seal assembly constructed in accordance with the present invention; and  
         [0026]      FIG. 15  is a perspective view of a spring seal formed in accordance with still another exemplary embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0027]     The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary embodiments and is not intended to represent the only forms in which the exemplary embodiments may be constructed and/or utilized. The description sets forth the functions and the sequence of steps for constructing and operating the exemplary embodiments in connection with the illustrated embodiments. However, it is to be understood that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.  
         [0028]     Some embodiments of the invention will be described in detail with reference to the related drawings of  FIGS. 1-15 . Additional embodiments, features and/or advantages of the invention will become apparent from the ensuing description or may be learned by practicing the invention. In the figures, the drawings are not to scale with like numerals referring to like features throughout both the drawings and the description.  
         [0029]      FIG. 1  is a cross-sectional view of a typical mechanical spring seal jacket or cover  10  having a seal cavity  40 , heel  41  and sealing lips  13 . Jacket  10  may be made of typical sealing materials such as Nylon or Teflon. Seal cavity  40  may receive a typical canted coil spring  20  ( FIG. 5 ), a typical flat ribbon coil spring  14  ( FIG. 6 ), a typical modified “C” shaped spring  12  ( FIG. 7 ), a typical straight cantilever U/V type spring  16  ( FIG. 8 ) or a typical elastomeric O-ring  21  ( FIG. 9 ).  
         [0030]      FIG. 2  is a plan view of a flat spring strip element  44  configured in accordance with one exemplary embodiment of the present invention. Spring element  44  may be fabricated from resilient metal sold under the trademark Elgiloy™ or the like, with a plurality of slanted or angled (α) notches  48  and arms  50  with angle α (alpha) being anywhere between 5° and 45°. Notch angle α may be formed between a vertical axis of the plane defined by flat spring element  44  and the inner wall of a notch, as schematically shown in  FIG. 2 . Metal strips suitable for fabricating the spring element of the present invention may be obtained from Elgiloy Specialty Metals of Elgin, Ill. or its distributors. Other suitable material(s) may be utilized as needed.  
         [0031]      FIG. 3  is a front elevation of a spring  47  which is formed by bending the slanted arm ends of flat spring strip element  44  in accordance with another exemplary embodiment of the present invention. With this slanted configuration the length of spring arm  50  is increased relative to conventional spring seals which have a vertical spring arm configuration. A person skilled in the art would readily recognize that the increase in spring arm length made possible by the slanted configuration of the present invention does not affect the spring height (h) (FIG.  4 ) and overall seal assembly length thereby achieving enhanced resiliency in overall seal performance.  
         [0032]      FIG. 4  is a cross-sectional view of a spring seal  49  which is formed by folding spring  47  about its longitudinal axis  45  ( FIGS. 3-4 ) in accordance with yet another exemplary embodiment of the present invention. Spring seal  49  has a seal height (h) ( FIG. 4 ) and may be adapted to be fitted inside a conventional seal jacket, such as jacket  10 , as schematically illustrated in reference to  FIG. 10 . In this regard, one should not confuse the novel spring seal assembly of  FIG. 10  with the conventional spring seal assembly of  FIG. 7 . Particularly, arms  50  of spring seal  49  of  FIG. 10  in reality are longer (because of their slanted configuration), while the spring arms of modified “C” shaped spring  12  of  FIG. 7  are shorter.  
         [0033]      FIG. 5  is a cross-sectional spring seal assembly view showing seal jacket  10  containing a typical spring element of canted coil  20 .  FIG. 6  is another cross-sectional spring seal assembly view showing a typical flat ribbon coil spring  14  fitted inside seal jacket  10 .  FIG. 7  is yet another cross-sectional spring seal assembly view of a typical modified “C” shaped spring  12  fitted inside seal jacket  10 .  FIG. 8  is still another cross-sectional spring seal assembly view of a typical straight cantilever U/V type spring  16  fitted inside seal jacket  10 .  FIG. 9  is a further cross-sectional spring seal assembly view of a typical elastomeric O-ring  21  inserted inside seal jacket  10 .  
         [0034]     The present invention may be effectively utilized in seal glands fabricated in industry particularly in aerospace where smaller and lighter more efficient units are needed. The spring element of the present invention may be used with various types of conventional seal jackets, such as jacket  10  ( FIG. 1 ). These jackets may be made of materials than Nylon or Teflon. These materials are subjected to constant pressure and fatigue as forces are being exerted on sealing lips  13  of jacket  10  ( FIG. 1 ). Even though these jacket materials may become hardened and brittle as a result of continuous operation, the spring element of the present invention would keep its resiliency so that seal assembly of  FIG. 10  could maintain its overall performance.  
         [0035]      FIG. 11  is a plan view of a resilient flat spring  53  with a substantially criss-cross or lattice configuration formed by superimposing flat spring strip element  44  of  FIG. 2  onto oppositely oriented flat spring strip element  51  ( FIG. 11 ). Specifically, flat spring strip element  51  has oppositely oriented notches and seal arms  52  ( FIG. 11 ) relative to the notches and seal arms  50  of spring strip element  44  ( FIGS. 2, 11 ) in accordance with an alternative embodiment of the present invention. The criss-cross or lattice configuration of this embodiment enhances the overall resiliency, strength and durability of spring  53 . Flat spring strip element  51  ( FIG. 11 ) may also be made from resilient metal sold under the trademark Elgiloy™ and/or other suitable material(s), as needed.  
         [0036]      FIG. 12  is a front elevation of a spring  54  formed by bending the slanted and criss-crossed seal arm ends of resilient flat spring  53  of  FIG. 11  in accordance with another alternative embodiment of the present invention.  
         [0037]      FIG. 13  is a cross-sectional view of an enhanced spring seal  58  which is formed by folding spring  54  about its longitudinal axis  56  ( FIG. 12 ) in accordance with still another alternative embodiment of the present invention. While  FIG. 13  schematically shows the two superimposed spring strips ( 44 ,  51 ) being folded generally toward the reader, a person skilled in the art would appreciate that folding in the opposite direction is also possible. Other folding configurations may be employed, provided such other configurations do not depart from the intended purpose of the present invention.  
         [0038]     Enhanced spring seal  58  has a seal height (k) ( FIG. 13 ) and may be adapted to be fitted inside a conventional seal jacket, such as jacket  10 , as schematically illustrated in reference to  FIG. 14 . In this case, seal height k ( FIG. 13 ) would be less than seal height h of  FIG. 4 . The spring seal assembly of  FIG. 14  provides enhanced spring seal durability and resiliency during a variety of severe working environment conditions.  
         [0039]      FIG. 15  is a perspective view of a spring seal  60  formed in accordance with still another exemplary embodiment of the present invention. Spring seal  60  has a longitudinal axis  62  and arms and notches oriented similar to the arms ( 52 ) and notches of spring strip  51  ( FIG. 11 ).  
         [0040]     A person skilled in the art would appreciate that embodiments described hereinabove are merely illustrative of the general principles of the present invention. Other modifications or variations may be employed that are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations may be utilized in accordance with the teachings herein. Accordingly, the drawings and description are illustrative and not meant to be a limitation thereof.  
         [0041]     Moreover, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Thus, it is intended that the invention cover all embodiments and variations thereof as long as such embodiments and variations come within the scope of the appended claims and their equivalents.