Abstract:
A hydrodynamic seal efficiently protects an interior cavity of an enclosure from external elements. The seal has an upper portion having a recess formed in a center section of the upper portion. A lower portion, having a raised portion, abuts the upper portion and forms a passage between the two portions. The passage between the upper and lower portions is reduced in area along the recessed and raised portions. When air with water and/or dust passes through the passage, a velocity and pressure change occurs, thereby the water and/or dust is deposited in a channel. The water and/or dust flows along the channel and is exhausted to an external so that the water and/or dust is prevented from entering the interior cavity of the enclosure.

Description:
This invention relates to seals and sealing methods. More particularly, the present invention relates to a hydrodynamic seal and a method for providing the same. 
     BACKGROUND OF THE INVENTION 
     In order to protect an interior of a container or enclosure, e.g., circuit enclosures designed to be placed on telephone poles, electrical poles, or homes, the container or enclosure is typically provided with a rubber gasket, gaskets, or the like, positioned along a lip or flange where a top-half and a bottom-half of the container or enclosure meet when the container or enclosure is in a closed position. The rubber gasket is designed to prevent rain, sand, dust, and other particles and debris from entering through the discontinuity formed by the top-half and bottom-half of such an enclosure. However, such an enclosure containment prevention design has specific operational disadvantages and manufacturing disadvantages associated therewith. 
     In particular, enclosures and containers to protect circuits, wires, and other electrical components, are typically made out of hardened plastic, metal, or the like. The use of such materials is advantageous since these materials can withstand harsh weather conditions for many years without failing. However, it has been found, due the rubber gasket material, or the like, used to protect the enclosures or containers from the exterior elements, preventive maintenance is required to ensure the rubber gasket is free of cracks, dry-rot, deterioration, or the like. Such a maintenance procedure requires a skilled technician to ensure that a rubber gasket installed on such a container or enclosure is free of defect. If the gasket is found to be damaged, then the technician must either replace the gasket in the container or enclosure, and/or the container or enclosure itself. This is a significant disadvantage since the container or enclosure must be inspected at regular intervals, and/or replaced before the exterior portion of the box would normally need replacing. 
     Another disadvantage in the design of the conventional container or enclosure, occurs at a manufacturing stage of the container or enclosure. Typically, if the container or enclosure is made of a hardened plastic material, then the manufacturing of such is normally done by a mold die. A mold die is manufactured in the desired shape of the enclosure or container. A plurality of these will be made, depending on the manufacturing quantity, and subsequently used during a manufacturing cycle. A molten plastic material is injected into the die, thereby forming the container or enclosure. Subsequent to this process, in order to weatherproof the enclosures or containers, a rubber gasket, or the like, must be adhesively applied to a flange or lip portion of the molded enclosure or container. This process of adhering a rubber gasket is an additional manufacturing step which must be accomplished by either a manual or automated process. Nonetheless, the process of adhering the rubber gasket requires a manufacturing stage which is in addition to the molding of the enclosure or container. 
     SUMMARY OF THE INVENTION 
     The hydrodynamic seal of the present invention overcomes one or more of the disadvantages associated with the sealing process of the conventional art. The hydrodynamic seal of the present invention is capable of protecting a cavity, such as an enclosure cavity for sensitive circuits or electronics from external elements without the use of a rubber gasket, or the like. Furthermore, the hydrodynamic seal of the present invention is capable of reducing manufacturing requirements for, but not limited to, enclosures and containers implementing rubber gaskets and seals. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
     FIG. 1 is a plan view of a circuit enclosure used to illustrate the hydrodynamic seal of the present invention; 
     FIG. 2 is a cross-sectional view taken along line A—A of FIG. 1, wherein the hydrodynamic seal of the present invention is illustrated; 
     FIG. 3 is an exploded cross-sectional view of the hydrodynamic seal; 
     FIG. 4 is a bottom view of the circuit enclosure used to illustrate the hydrodynamic seal of the present invention; and 
     FIG. 5 is an exploded cross-sectional view of the hydrodynamic seal, used to illustrate the functionality of the pressure/velocity differentials. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 illustrates a wire or circuit enclosure  10  including the hydrodynamic seal  12  (seen in other figures) of the present invention. The circuit or wire enclosure  10  has been used for illustration purposes only. The hydrodynamic seal  12  of the present invention applies to various other containers and enclosures which have not been discussed herein, but would be readily discernable by those skilled in the art. 
     FIG. 2 is a cross-sectional view of the circuit enclosure  10  illustrating the hydrodynamic seal  12  of the present invention. The hydrodynamic seal  12  is formed when the circuit enclosure  10  is in the shut position. The shut position is achieved when a top lid  14  is rotated around a hinge  16  such that the top lid  14  abuts with a bottom section  18 . The hydrodynamic seal  12  is formed along an upper portion  20  of the top lid  14  and a lower portion  22  of the bottom section  18  and spans the entire perimeter of the circuit enclosure  10  except a bottom end  48  thereof. 
     FIG. 3 illustrates an expanded view of the hydrodynamic seal  12  shown in FIG.  2 . The upper portion  20  of the hydrodynamic seal  12  is divided into various portions. A first portion  24  is at a distal end of the upper portion  20 . A second portion  26  is formed directly adjacent to the first portion  24  and has a recessed semicircular concave definition formed therein. A third portion  28  further defines the upper portion  20  and is positioned adjacent the second portion  26 . The first portion  24 , the second portion  26 , and the third portion  28  comprise the entire upper portion  20 . 
     A lower portion  22  extends from the bottom section  18 . The lower portion  22  is defined as having a fourth portion  30 , a fifth portion  32 , and a sixth portion  34 . The fifth portion  32  of the lower portion  22  is raised and forms a semicircular rise. The sixth portion  34  has a channel portion  36  centered therein and is further defined by an elongated part  56  which extends along an interior surface of the top lid  14 . The fourth portion  30 , the fifth portion  32 , the sixth portion  34 , and the channel portion  36  form the entire length of the lower portion  22 . 
     Although the second portion  26  is defined as being semicircular concave in shape and the fifth portion  32  is defined as being raised and semicircular, the portions may have other various mating shapes. For example, the second portion  26  may be triangular concave in shape and the lower portion  22  may be raised and triangular in shape. The various other shapes may be implemented, and as such they are embraced by the scope of the invention. Furthermore, the second portion  26  and the fifth portion  32  may be positioned such that the raised portion is part of the upper portion  20  and the concave portion is part of the lower portion  22 . 
     When the top lip  14  is rotated about the hinge  16  to abut the bottom section  18 , the hydrodynamic seal  12  of the present invention is formed between the upper portion  20  and the lower portion  22 , respectively. The passage defined between the upper portion  20  and the lower portion  22  defines various sections of area formed by the portions described hereinabove. 
     A first area  38  is formed between the first portion  24  and the fourth portion  30 . Furthermore, a second area  40  is formed between the second portion  26  and the fifth portion  32  of the upper portion  20  and the lower portion  22 , respectively. While the third portion  28  and the sixth portion  34  form a third area  42 . The channel portion  36  defined in the lower portion  22  forms a fourth area  44  in addition to the third area  42  defined by the third portion  28  and the sixth portion  34 . The defined areas of the hydrodynamic seal  12  are predetermined based on the overall size of the enclosure or container, or the like, on which the hydrodynamic seal  12  is employed. 
     In accordance with the present invention, as shown with the circuit enclosure  10 , the first area  38  has a predetermined area which is defined between the first portion  24  and the fourth portion  30 . The second area  40 , formed between the second portion  26  and the fifth portion  32 , is predetermined and is less than the first area  38 . The third area  42 , not including the fourth area  44  defined by the channel portion  36 , is equal to the first area  38 . While, the fourth area  44 , formed by the channel portion  36 , has a predetermined area which is greater than each of the first area  38 , the second area  40 , and the third area  42 . 
     FIG. 4 is a bottom view of the circuit enclosure  10  used to illustrate the hydrodynamic seal  12  of the present invention. Shown on the bottom end  48  of the circuit enclosure  10  are channel exits  46 . The channel exits  46 , according to the circuit enclosure  10  used to illustrate the hydrodynamic seal  12  of the present invention, are not limited to the positions as shown in FIG.  4 . Depending upon the design of the container or enclosure the hydrodynamic seal  12  is implemented on, the positions of the channel exits  46  may be implemented at a wide range of locations along the bottom edge of such a container or enclosure. Moreover, the channel exit  46  may be positioned in any location on such a container or enclosure provided that the channel exits  46  are positioned at a bottom end portion of the container or enclosure when the container or enclosure is operationally positioned. 
     FIG. 5 illustrates the fundamental operation of the hydrodynamic seal  12 . When circuit enclosure  10  is in a shut state, the upper portion  20  and the lower portion  22  form a passage defined therebetween. During operation of the hydrodynamic seal  12 , an inflow of gas  50  containing an arbitrary level of water and/or dust  52 , enters the first area  38 . The pressure and velocity of the gas  50  containing the water and/or dust  52 , while in the first area  38 , remains constant to a pressure and velocity of the gas  50  before it entered the first area  38 . The gas  50  with the water and/or dust particles  52  travels along the first area  38  and enters the second area  40 . At this point, since the second area  40  has a smaller area as compared to the first area  38 , the gas  50  with the water and/or dust particles  52  experiences a pressure rise, while maintaining the same velocity experienced in the first area  38 . The gas  50  with the water and/or dust particles  52  now enters the third area  42 . The third area  42  has essentially the same area as the first area  38 , but is larger than the second area  40 . At this point, the gas  50  with the water and/or dust particles  52  experiences a pressure and velocity drop due to the larger third area  42  as compared to the second area  40 . Subsequently, as the gas  50  with water and/or dust particles  52  passes over the channel portion  36 , due to the pressure and velocity drop, the water and/or dust particles  52  which are traveling with the gas  50  fall away into the channel portion  36 . 
     The channel portion  36  is defined by the fourth area  44 , which has an area greater than each of the first, second, and third areas individually. Therefore, the pressure and velocity again drop significantly, thereby further facilitating the deposit of the water and/or dust particles  52  into the channel  36 . After having deposited the water and/or dust particles  52  in the channel portion  36 , the inflow of gas  50  moves by the remainder of the sixth portion  34  and past the elongated part  56  which provides a directional change in the inflow of the gas  50 . Any remaining particles of the water and/or dust  52  in the inflow of the gas  50  lose any remaining momentum and fall into the channel portion  36 . The elongated part  56  further facilitates preventing the water and/or dust particles  52  from leaving the channel portion  36 . The gas  50  is then exhausted into the cavity portion  54 . 
     As compared to the other areas discussed, an area defined by the cavity portion  54  is much greater than the areas defined by the hydrodynamic seal  12 . Therefore, the inflow of gas  50  experiences a final pressure and velocity drop such that the flow of the gas  50  becomes negligible as compared to the original inflow of the gas  50 . 
     Although the present invention has been illustrated in conjunction with the circuit enclosure  10 , it should be readily apparent that the invention would be suitable for different types of enclosures and containers. For example, the hydrodynamic seal  12  of the present invention is readily suitable for containers or enclosures, of various sizes and shapes, which require protection from water, particles, dust, or the like. The hydradynamic seal  12  is also suitable outside the container art in any application where a debris and water tight seal is desired between two mating objects. 
     The invention being thus described, it would be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.