Abstract:
A double walled solar shielding system for an electrical enclosure includes an inner enclosure defining a substantially rectangular box with an inner door pivotally mounted to the inner enclosure. A shielding layer extends around the top, rear and lateral sides of the enclosure with a shielding door mounted coaxially with the inner door and having an outer layer spaced apart from the inner door. The doors open independently and may have different security measures. The system includes modular elements and may be retrofitted to existing enclosures.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a solar shield system for an outdoor electrical enclosure, and in particular to a solar shield providing ventilation that may be retrofitted to existing electrical enclosures.  
           [0003]    2. Prior Art  
           [0004]    Electrical enclosures are often placed in remote outdoor environments to house electronics and other components within the enclosure. Often, such enclosures are mounted on a pole and are accessed periodically for servicing the internal components, reading meters and other gauges, and for other monitoring and maintenance, as may be needed. The boxes normally require some security measures and may require more than one level of security depending on the access needs of different persons. Some of these enclosure boxes may require security only to allow gauges to be read, which may be possible by looking through a transparent door or other view port. Still others require additional security providing controlled access to internal components for servicing.  
           [0005]    The enclosures must also provide protection from the elements. The enclosure should protect components from wind and rain while maintaining durability. Such enclosures should also prevent insects, rodents and other pests from gaining access to the equipment housed in the enclosure.  
           [0006]    Components that are typically placed in the enclosure may be heat sensitive. Therefore, it may be necessary to provide some solar shielding and ventilation for cooling to prevent overheating. As the enclosures are often very remote, servicing of active cooling systems using fans, circulating cooling fluids, or other systems may be difficult. Moreover, the cost of an active cooling system for large numbers of such enclosures may be prohibitive. Therefore, a passive cooling system is often desired that utilizes natural ventilation between double walls.  
           [0007]    Heretofore, there has not been an enclosure providing sufficient solar shielding and security. The typical approach to address the problem has been to design a box within a box. Although such a design does provide shielding and may provide some security, the design usually shields all sides, including the bottom, where solar shielding is unnecessary, and is over-designed for the needs of a typical enclosure. Such designs often fall short in providing doors that open with a sufficient range to provide full access. Moreover, such designs typically cannot be retrofitted to existing enclosures.  
           [0008]    Problems have also been encountered with sealed enclosures due to wear on the gasket from rubbing against another surface during opening and closing of the door, commonly know as “swiping.” Providing a good seal while avoiding swiping becomes a greater challenge when multiple access doors to a single opening are utilized.  
           [0009]    It can be seen then that a new and improved electrical enclosure with solar shielding is needed. Such an enclosure should provide protection from the elements and a degree of passive cooling for the interior of the enclosure. Such a shielding system should provide double walled construction and provide for retrofitting to existing enclosures. In addition, it is preferable to provide security measures for accessing the interior of the enclosure through a double layer door. The present invention addresses these problems, as well as others associated with outdoor solar-shielded electrical enclosures.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention is directed to solar shield systems for electrical enclosures that are typically placed outside and exposed to the elements. The shielding system provides a double-walled shield that allows cooling air to circulate between the outer wall and inner wall. The shielding elements cover the front, back, sides and top to protect an inner enclosure from sun and provide passive cooling for the inner enclosure. The outer shielding elements each cover only one side or the door of the inner enclosure so that shielding can be retrofitted to existing enclosures. Therefore, the various shielding elements may be mixed and matched so that the present system may be used with enclosures of different sizes.  
           [0011]    Various shielding elements are fitted together and overlap so that shielding surrounds all sides except the bottom of the enclosure. The present invention also includes a shielding element over the door of the inner enclosure. In a preferred embodiment, the door cover pivots about the same hinge as inner enclosure door for improved access and ease of providing security measures. The inner door and outer cover include one or more latches with various security measures, such as tool actuation or a key actuated latch. Different levels of security may be utilized to provide access to different persons at different levels and also provides for different degrees of access, such as access only to viewing the inner door or access to the interior of the inner enclosure. For example, a first key or tool may be needed to open the outer door, while a second key or tool may be necessary to open the inner door, thereby creating different security levels for different levels of access. The door system also is spaced apart from the inner enclosure to prevent portions of either of the doors from swiping other elements and for an improved range of motion so that the entire interior enclosure may be easily accessed without interruption from the door.  
           [0012]    These features of novelty and various other advantages, which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    Referring now to the drawings, wherein likes reference numerals and letters indicate corresponding structure throughout the several views:  
         [0014]    [0014]FIG. 1 shows a front elevational view of a first embodiment of a shielded enclosure apparatus according to the principles of the present invention;  
         [0015]    [0015]FIG. 2 shows a side elevational view of the shielded enclosure apparatus shown in FIG. 1;  
         [0016]    [0016]FIG. 3 shows a rear elevational view of the shielded enclosure apparatus shown in FIG. 1;  
         [0017]    [0017]FIG. 4 shows a top sectional view, take along line  4 - 4  of FIG. 3;  
         [0018]    [0018]FIG. 5 shows a bottom plan view of the shielded enclosure apparatus shown in FIG. 1, with the doors in an open position;  
         [0019]    [0019]FIG. 6 shows a front perspective view of an inner enclosure for a second embodiment of a solar-shielded enclosure, according to the principles of the present invention;  
         [0020]    [0020]FIG. 7 shows a right side elevational view of the inner enclosure shown in FIG. 6;  
         [0021]    [0021]FIG. 8 shows a front elevational view of the inner enclosure shown in FIG. 6 with an inner door mounted to the inner enclosure;  
         [0022]    [0022]FIG. 9 shows a top sectional view of the inner enclosure shown in FIG. 6 with solar shielding mounted to the front, sides and rear of the inner enclosure;  
         [0023]    [0023]FIG. 10 shows a top plan view of the outer door shielding for the shielded enclosure shown in FIG. 6;  
         [0024]    [0024]FIG. 11 shows a top plan view of the inner enclosure shielding for the solar-shielded enclosure shown in FIG. 6;  
         [0025]    [0025]FIG. 12 shows front elevational view of a third embodiment of a solar-shielded enclosure according to the principles of the present invention;  
         [0026]    [0026]FIG. 13 shows a side elevational view of the solar-shielded enclosure shown in FIG. 12; and  
         [0027]    [0027]FIG. 14 shows a bottom plan view of the enclosure shown in FIG. 12. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]    Referring now to the drawings, and in particular to FIGS.  1 - 3 , there is shown a first embodiment of a solar-shielded enclosure, generally designated  20 . The shielded enclosure  20  includes an inner enclosure  22 . The inner enclosure  22  forms a protective inner compartment defining an opening configured for receiving a door assembly  28 . The inner enclosure  22  is typically sealed to keep dust and/or water out and may include electromagnetic shielding. The inner enclosure  22  is sized for the needs of each application, but may be similar to a typical electrical enclosure  122 , shown in FIG. 6. The enclosure  122  includes a top  130 , bottom  132 , sides  136 , and a rear  134 . In addition, an angled lip  138  extends around the opening to aid in sealing and closing to provide improved protection for the internal components housed therein.  
         [0029]    Referring to FIGS.  1 - 5 , solar shielding  24  surrounds the front, back, sides and top of the enclosure to provide protection from exposure to the sun and prevent excessive heat in the inner enclosure  22 . The solar shielding  24  provides a spaced apart wall that forms a ventilation space around the inner enclosure  22 . The shielding  24  forms a passive cooling system that helps to maintain the inner enclosure  22  at a lower temperature and protects the equipment housed therein.  
         [0030]    The shielding  24  includes modular components forming a shield, including a top shielding element  48 , a rear shielding element  50 , side shielding elements  52  and an outer door, which functions as shielding element  56 . The various shielding elements are double-walled and may include ventilation holes  54  to improve circulation while also preventing pests and other debris from entering or becoming lodged in the ventilation space. With a modular configuration, shielding may be optimized for various size enclosures with the present system by mixing and matching shielding elements. Both side elements  52  mount to the inner enclosure  22  with mounting flanges  74  while the rear shielding element  50  mounts to the inner enclosure  22  with flanges  74 . The various flanges extend over the top and the bottom of the enclosure to receive mounting hardware and maintain alignment. The top shielding element  48  mounts over the other elements and overlaps the other elements to provide continuous spaced apart shielding  24 . The shielding  24  provides a thermal wrap covering all sides and the top of the inner enclosure. It can be appreciated that with such an arrangement, the system utilized for constructing the shielding portion  24  can be retrofitted to existing enclosures already in the field.  
         [0031]    As shown most clearly in FIG. 5, the door assembly  28  mounts on a hinge  42  spaced apart from the walls of the inner enclosure  22 . The positioning of the hinge  42  and its axis provides for improved pivoting of an inner door  40  and the outer shielding door  56  without scraping or swiping of gasket  80  against any of the other surfaces of the enclosure  20 . When the inner door  40  is closed, the gasket  80  seals against a lip  38  extending around the opening to the enclosure  20 . The door assembly  28  may include a first latch  62  on the inner door and a second latch  64 . The latches  62  and  64  may include a retainer  68  and a tool actuated or key actuated opening cylinder  66  mounted thereto. With such a configuration, various degrees of security may be added and changed, depending on the needs of the application. For some applications, it would be necessary only to view the components. In such applications, a first degree of security may be added by allowing only certain persons viewing access to the enclosure by looking through the inner door  40 , which may be glass or other transparent material. Other persons may be given greater access and allowed to open the inner latch  62  and the inner door  40  and access the interior of the inner enclosure  22 . As shown most clearly in FIGS. 1 and 2, multiple latches may be mounted to the door assembly  28  for improved latching along the outer end of the doors. It will also be appreciated that one latch may include an added security measure so that various degrees of access to the inner enclosure  22  or just access to the inner door  40  may be achieved.  
         [0032]    As shown in FIG. 5, the outer door  56  includes an angled end portion proximate the hinge  42 . An angled end portion is also formed on the side shielding elements  52 . With such angling, the outer door  56  may be opened to a larger degree than is possible with the prior designs and provides the advantages of not swiping the gasket  80  against the enclosure surfaces during opening and closing due to the position of the spaced apart hinge  42 . In the embodiment shown, the outer door enclosure  56  may be opened to approximately one hundred twenty degrees. The inner door  40  may be opened to the same degree as the outer door  56 , pressing against the outer door  56 . Referring to FIG. 1, a doorstop  70  may be mounted on the inner door  40  to hold the inner door  40  and outer door  56  in the open position. This allows workers to access the components in the inner enclosure  22  without the door closing or having to hold the door assembly  28  at an open position. The doorstop  70  maintains the door assembly  28  at the open position even in outdoor applications, where wind and imbalance may tend to close the door assembly  28 .  
         [0033]    Referring now to FIGS.  6 - 11 , there is shown a second embodiment of a shielded enclosure, generally designated  120  and similar to enclosure  20 , described above. An inner enclosure  122  includes a top  130 , bottom  132 , back  134 , and sides  136 . A lip  138  extends around the periphery of the opening for improved opening and sealing. One edge of the lip  138  includes knuckles  46  for a hinge  142  as explained below. As shown in FIGS. 6 and 7, the inner enclosure  122  for the shielded enclosure  120  is shown. As explained above, the inner enclosure  122  is sized for the particular application. Referring to FIGS. 8 and 9, the shielded enclosure  120  is similar to the shielded enclosure  20 . The shielded enclosure  120  includes a single latch  164 , rather than multiple latches. The shielded enclosure  120  includes a top shielding element, and as shown in FIG. 9, shielding elements  150 ,  152  and  156 . Ventilation holes  154  provide for improved circulation around the inner enclosure  122  and cooling. The shielding elements  150  and  152  include angled complementary end portions for improved fit around the inner enclosure  122 . In addition, the hinge  142  is spaced apart from the inner enclosure  120 .  
         [0034]    A door assembly  128  of the outer door enclosure  156  includes an angled end cooperating with an angled end of the side shielding element  152  to provide for an improved pivoting range so that the door  128  may open to at least  120  degrees. As both ends of the outer door enclosure  156  are angled and the side elements  152  include angled ends, the shielding system provides interchangeability so that the door assembly  128  may be opened in either direction with the same parts. In addition, the hinge  142  is spaced apart on an angled mount  144  that may be mounted along either edge of the inner enclosure  122  to provide for improved opening and sealing without swiping of gasket  180  against any of the other components. The latch  64  includes an actuator  66  that may take on various embodiments for the required level of security and a retainer  68  cooperating with the actuator  66  and engaging the inside of the inner enclosure underneath the lip  138 .  
         [0035]    Referring to FIG. 11, the side elements  152  and rear element  150  may be assembled prior to the mounting to the inner enclosure. The assembly may simply be slid onto and over the rear of the inner enclosure with flange portions  172  and  174  sliding over the top  130  along the inner enclosure  122 . This arrangement helps to guide and align the shielding and the inner enclosure  122  for improved fit. Moreover, the angled end portions  160  provide for opening the door assembly  128  in either direction. The shielding assembly  124  may also be assembled one piece at a time and may be utilized to retrofit to existing enclosures.  
         [0036]    Referring now to FIGS.  12 - 14 , there is shown a third embodiment of a shielded enclosure, generally designated  220 . The shielded enclosure  220  includes an inner enclosure  222  with outer solar shielding forming enclosed solar shield  224 . The solar shield  224  includes a top shielding element  248 . The top shielding element  248  includes an angled upper surface to aid in shedding rain, snow and debris, and also includes side louvers  280 . The louvers  280  improve airflow into and out of the top element  248 . In addition, rear element  250  and side elements  252  wrap around the inner enclosure  222 , as shown most clearly in FIG. 14. The elements  250  and  252  typically include ventilation holes  254  that improve circulation and airflow. An outer door enclosure  256  wraps around part of a door assembly  228 . The door assembly  228  includes a hinge  242  spaced apart from the inner enclosure  222  mounted on an angled mounting element  244 . The ends  260  of the side elements  252  are angled to cooperate with the angled ends of the outer enclosure  256  to provide an improved range of motion. A latch  264  has an actuator  266  and a retainer  268  wrapping around a lip  238  of the inner enclosure  222 . The latch  264  may be actuated with different degrees of security for limiting and controlling access to the enclosure and providing different degrees of security and access to the enclosure  220 . The door assembly  228  includes an inner door  240 , which also pivots about the same hinge  242 . The spacing of the doors  240  and  256  pivoting about the hinge  242  provides improved access and controlled access to the inner enclosure  222 .  
         [0037]    It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.