You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
OBJECT OF THE INVENTION  
         [0001]    The invention consists of a sealing device for a manhole intended to provide an hermetic seal for the access mouth with the aid of a lid that forms part of the assembly of the device.  
           [0002]    The sealing device ensures the securing of the lid in the access mouth in order to prevent any infiltration of fluids from the outside or escape of gases from the interior.  
         BACKGROUND OF THE INVENTION  
         [0003]    Manholes currently include an access opening or mouth where a sealing lid is fitted in order to isolate the interior of the hole from the exterior in order to protect the contents of that hole.  
           [0004]    The lid is normally associated with a sealing device that ensures the fastening of said lid in order to provide tightness and imperviousness in the seal so as to prevent any infiltration of fluids or gases from the outside to the interior.  
           [0005]    Utility model No. 9800352 consists of a sealing device for underground tanks that includes a lid that fits into a frame provided in correspondence with the access mouth to the tank. This lid rests against a sealing O-ring housed in a perimetric groove in the frame. The sealing device basically consists of a crosspiece whose ends are associated with the frame, while at the same time a central screw threads onto this crosspiece in order to secure the lid against the O-ring, this latter being the element which, along with the lid, provides the tank with its imperviousness.  
           [0006]    The device of utility model number 9800352 presents the drawback that, after a period of time, the imperviousness of the tank becomes reduced and the seal loses its effectiveness, mainly due to the weakness of the structure presented by the crosspiece where the securing screw threads into the lid, in such a way that, after a while, it becomes deformed and arches upwards, with which the pressure of the lid on the O-ring becomes reduced and the tank therefore loses its tightness.  
           [0007]    Another drawback is that after a while, when the access lid is removed, the O-ring sticks to the lid, causing it to become dislodged from its position, which thereby creates the danger of the ring falling into the tank.  
         DESCRIPTION OF THE INVENTION  
         [0008]    In order to achieve the objectives and to avoid the drawbacks mentioned in the above paragraphs, the sealing device for manholes is characterised in that it includes a new sealing joint with a profile that is clasped to at least a portion of the frame made in the mouth of the hole, a lid which will rest on said joint being secured on the frame. In this way, the joint will at all times remain on the frame without becoming detached from it when the lid is removed.  
           [0009]    The device is also characterised in that the lower face of the lid includes a perimetric inclined band that in a complementary way makes contact against the sealing joint, thereby achieving a better seal.  
           [0010]    Another improvement refers to the structure presented by the crosspiece wherein the screw is threaded for securing the lid. Unlike the crosspiece of the utility model mentioned in the previous section, this crosspiece does not arch when the screw is tightened, which means the imperviousness of the lid is not adversely affected.  
           [0011]    Another characteristic of the invention consists of the means of linking the crosspiece on the frame of the access mouth to the interior of the hole. Thus, instead of the springs used in utility model No. 9800352, in the present invention a plurality of simple conventional mechanisms for quick locking and a plurality of lower stops are used, which substantially facilitate the extraction of the respective crosspiece. When the quick locking mechanisms are unlocked, the crosspiece rests on the lower stops.  
           [0012]    Another improvement to the device refers to the fact that the frame includes means for preventing its deformation when the lid is secured and tightened.  
           [0013]    In order to aid a better understanding of the invention, the description is accompanied by figures representing the object of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 represents an exploded perspective view of the sealing device assembly for the manhole, forming the object of the invention. It basically includes a frame, to which is coupled an access lid to the inside of the hole with the interposition of a sealing joint. It also includes at least one crosspiece associated with the frame and in which is secured the lid with the aid of a central screw.  
         [0015]    [0015]FIG. 2 represents a plan view of the device of the invention.  
         [0016]    [0016]FIG. 3 represents a view in cross-section along line A-B of the previous figure.  
         [0017]    [0017]FIG. 4 represents a view of part of the device mainly showing some seating and retention stops for the crosspiece.  
         [0018]    [0018]FIG. 5 shows a securing fastening f or the frame of the device of the invention.  
         [0019]    [0019]FIG. 6 essentially shows a mechanism for hooking the crosspiece to the frame.  
         [0020]    [0020]FIG. 7 shows a schematic plan view of the crosspiece linked to the frame by means of a vertical articulated coupling.  
         [0021]    [0021]FIG. 8 shows a similar view to the previous one, where the crosspiece is linked to the frame by means of a horizontal articulated coupling.  
         [0022]    [0022]FIG. 9 shows a perspective view where the crosspiece is associated with the frame by means of a vertical articulated coupling that presents a different structure with respect to that represented in FIG. 7. 
     
    
     DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION  
       [0023]    An example of an embodiment of the invention following the numbering system adopted in the figures is described below.  
         [0024]    The sealing device for the manhole is made on the basis of a frame  1  which is fixed on an access mouth or opening  2  made in correspondence with the ground.  
         [0025]    The frame  1  includes an exterior rim  3  embedded beneath the ground and an interior rim  4  on which a sealing lid  5  rests with interposition of a sealing joint  6  which couples to and clasps the interior rim  4 .  
         [0026]    The joint  6  includes an upper inclined plane  7  on which the inclined plane of a lower perimetric band  8  of the lid  5  rests in a complementary fashion, in such a way that when the lid  5  is secured, a hermetic seal which is highly effective and progressive in line with the tightening of the lid against the joint  6 , is achieved.  
         [0027]    The interior rim  4  is provided with a channel  9  in which an exterior flange of the sealing joint  6  is housed. On the other hand, the internal end of the joint  6  ends in another bent section  11  that clasps the inside part of the internal rim  4  of the frame  1 .  
         [0028]    The securing of the lid  5  is done by means of at least one crosspiece  12  that is associated via its ends to the frame  1 . In order to achieve this, the ends of said crosspiece  12  include a plurality of elongations  13  facing a plurality of upper pieces  14  made integral with the frame  1 , in such a way that one of the elongations  13  of the crosspiece  12  is coupled in an articulated fashion to the frame  1 , either by means of a horizontal axis  15  (FIG. 8) or by means of a vertical axis  16  (FIG. 7) which links one of the elongations  13  of the crosspiece  12  with the respective upper piece  14 . On the contrary, the other end section of the crosspiece  12  includes a conventional fast locking mechanism  17  which hooks to a small bent extension  18  emerging from the other upper piece  14  integral with the frame  1 .  
         [0029]    When it is necessary to gain access to the interior of the hole, once the hook mechanism  17  has been released, the crosspiece will be displaced to one side when the articulation of the crosspiece  12  is vertical (FIG. 7) or upwards when the articulation of the crosspiece  12  is horizontal (FIG. 8).  
         [0030]    The framework  1  includes a plurality of stops  19  essentially determined by a plurality of screws found below the end elongations  13  of the crosspiece  12 , in such a way that when the crosspiece is extracted, or when the crosspiece is released, it will be retained and its own weight will cause it to rest on the screwed stops  19 .  
         [0031]    Finally, it may be pointed out that the frame  1  includes a plurality of fastenings  20  embedded beneath the ground in order to prevent any deformation to the frame when the lid  5  is tightened and secured by means of a screw  21  passing through a central opening  22  in the lid  5  in order to couple with a threaded hole  23  of a short vertical extension  24  integral with the crosspiece  12 , which presents a profile essentially in form of a double “T” in orders to prevent deformations to it when the securing screw  21  is tightened.  
         [0032]    The fastenings  20  are located at least in the opposite zones of the frame  1  where the end elongations  13  of the crosspiece  12  are secured, since when fitting the sealing lid  5  it is precisely in those opposite zones of the crosspiece  12  where the crosspiece  12  grips most.

Summary:
This concerns a sealing device that ensures the hermetic securing of the lid ( 5 ) in the access mouth ( 2 ) in order to prevent any infiltration of fluids from the outside or escape of gases from the interior.  
     It basically comprises a frame ( 1 ), a lid ( 5 ) that rests on said frame ( 1 ) with interposition of a sealing joint ( 6 ), and a crosspiece ( 12 ) in order to facilitate the securing of the lid ( 5 ) with the aid of a screw ( 21 ).  
     The sealing joint ( 6 ) presents a special structure that permits complete imperviousness be obtained in the sealing of the device.