Abstract:
A remotely activated tank hatch system includes an upper frame and a lower frame joined by a hinge assembly. The lower frame is coupled to a collar of an opening of a tank and a hatch is coupled to the upper frame. The hinge assembly allows the upper frame to pivot the hatch between an open and closed position. The lower frame includes at least one catch to receive an edge of the hatch, when the hatch is closed. Spring members on the upper frame urge the hatch toward the upper frame so that the hatch may be swung away from the opening. Inflating a rubber bladder positioned between the upper frame and hatch overcomes the spring pressure and urges the hatch into tight contact with the collar. The hatch system includes a remote control for inflating the bladder and opening and closing the hatch.

Description:
REFERENCE TO CROSS-RELATED APPLICATIONS 
     This application claims priority to provisional application No. 60/538,624, filed on Jan. 23, 2004. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to hatch systems for use on tanks, and more particularly, to remotely operated hatch systems for tanks and bulk carriers, such as those carried by trucks and trains. 
     2. Background Information 
     Commercial tanks, also commonly known as “tankers” and “bulk carriers”, are widely used for transporting both liquid and dry goods. Tanks are configured with hatches to open and close an opening in the top of the tank, to access to the interior of the tank. Opening or closing the hatch often requires an operator to climb on top of the tank to manually release securing or locking mechanisms that keep the hatch closed. The operator then must lift or otherwise move the hatch cover to open the hatch. This operation can be hazardous to the operator, because a fall from the typical height of the top of the tank may cause injury, and because the contents of many such tanks often include vapors or gases which may be toxic or unpleasant. Inclement weather and moisture or ice on the top of the tank can increase the danger associated with climbing up on the tank and operating the hatch securing mechanism. 
     Since some types of goods transported by tank are transported under pressure, some tanks have opening closures that must withstand a pressure differential between internal and external pressures. For example, some tanks are used for the storage or transportation of granular or powder form dry bulk goods such as flour, salt, cement, lime, and cereal grains. These dry bulk goods are pneumatically transferred into the tank from a storage facility, via a pneumatic transfer system. Pneumatic transfer systems do not work properly unless the closure on the access port of the tank can maintain a pressure differential between the interior pressure of the tank and exterior pressure on the tank. 
     Automated hatch opening and closing systems have been devised in the prior art to allow remote operation of a hatch. Some of these systems can be retrofit on existing manually-operated hatches. Many preexisting automated hatch systems suffer from a number of disadvantages. One known disadvantage of these prior art hatch systems is that these systems are prone to leak when pressurized. Another known disadvantage to these systems is that significant modification is required to retrofit the preexisting tanks, which can be costly and time consuming to retrofit. Another known disadvantage of the prior art systems is that they may be complicated to install and somewhat expensive to purchase. A further known disadvantage of the prior art systems is that they may open the hatch vertically, thus potentially obstructing tank-filling equipment. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention includes hatch systems for use on tanks and bulk carriers. One embodiment built in accord with the invention is a remotely operated hatch system for tanks and bulk carriers, such as those carried by trucks and trains. 
     The invented hatch system may comprise an upper frame and a lower frame that are joined by a hinge assembly. The lower frame is coupled to a collar of an opening of the tank and the hatch is coupled to the upper frame. The hinge assembly allows the upper frame to pivot the hatch between an open and closed position relative to the opening of the tank. The frame may also include at least one catch that is intended to receive an edge of the frame, when the hatch is closed. 
     A plurality of spring members on the upper frame are configured to urge the hatch upward and away from the tank opening. This provides a space between the opening of the tank and the hatch, so that the hatch may be swung away from the opening and thus not obstruct equipment used to fill the tank. An inflatable bladder may be positioned between the upper frame and the hatch. Inflating the bladder overcomes the spring pressure and urges the hatch into tight contact with the opening of the tank. The hatch system also includes a remote control means for inflating the bladder and for rotating the hatch between the open and closed positions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which: 
         FIG. 1  is a side view of an embodiment of a remotely activated tank hatch system of the invention in closed position; 
         FIG. 1A  is a side view of an embodiment of the invention where helical springs are visible; 
         FIG. 2  is a side view of an embodiment of the invention in closed position and further showing a remote control panel of the invention; 
         FIG. 3  is a side view of an embodiment of the invention in a partially open position; 
         FIG. 4  is a side view of an embodiment of the invention in a fully open position and showing the panel of the invention; 
         FIG. 5  is a perspective view of an embodiment of a hinge assembly of the invention; 
         FIG. 6  is a perspective view of an embodiment of a hinge assembly of the invention; 
         FIG. 7  is a perspective view of an embodiment of a pivot mechanism of the hinge assembly of the invention; 
         FIG. 8  is a detail view of an example of a lower frame of the invention; 
         FIG. 9  is a side view of an embodiment of a catch of the invention 
         FIG. 10  is a top perspective view of an embodiment of an upper frame of the remotely activated tank hatch system of the present invention; and 
         FIG. 11  is a perspective view of an alternative embodiment of an inflatable member of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention includes hatch systems for use on tanks. One embodiment built in accord with the invention is a remotely operated hatch system for tanks and bulk carriers, such as those carried by trucks and trains. 
     Reference will now be made in detail to a presently preferred example embodiment of the invention as illustrated in the accompanying drawings. The invented hatch system shown in  FIGS. 1-10  is provided as an example only, and although the examples given include many specifics, they are illustrative of only a few possible embodiments of the invention. Other embodiments and modifications will no doubt occur to those skilled in the art. The examples given should only be interpreted as illustrations of some of the preferred embodiments of the invention, and the full scope of the invention is comprehended to include alternate designs which may not be specifically disclosed herein. 
     Referring to the drawing Figures, there is shown generally at  10 , an embodiment of a remotely activated tank hatch system of the present invention. The hatch system  10  is shown coupled to a collar  12  defining a tank opening  14  of a tank  16 . It is to be understood that the tank  16  may comprise any commercial tank or bulk carrier, such as those carried by trucks and trains, for example. 
     Referring to  FIG. 1  through  FIG. 4 ,  FIG. 8 , and  FIG. 10  of the drawings, the invented hatch system  10  may include an upper frame, shown generally at  18 , and a lower frame, shown generally at  20 , that are coupled by a hinge assembly  22 . The lower frame  20  is coupled to the collar  12  and a hatch  24  is coupled to the upper frame  18 , for enclosing the opening  14 . 
     Referring to  FIG. 3 ,  FIG. 4 ,  FIG. 8 , and  FIG. 10 , the lower frame  20  may include an arcuate, U-channel member  26 . The channel member  26  may have a lower edge  28  and an upper edge  30 . A plurality of support members  32  may be spatially positioned along the channel member  26  for strengthening it. The lower edge  28  of the channel member  26  may be configured to extend about the periphery of the collar  12  and is coupled thereto. 
     Referring particularly to  FIG. 1  and  FIG. 8 , in the embodiment shown, the collar  12  is configured tabs  34  that are spatially positioned about its periphery. The lower edge  28  of the channel member  26  may be configured with pairs of vertically extending flanges  36 . Adjacent flanges  36  are positioned to extend over each side of a tab  34 . A hole  38  (not clearly seen) may bored though each tab  34  and a corresponding opening  40  may also be formed in adjacent flanges  36 . The tabs  34  are positioned between adjacent flanges  36  until the hole  38  in the tab  34  is aligned with the openings  40  in the flanges  36 . A pin  42  may then be inserted through the opening  40  in one of the flanges  36 , then through the hole  38  in the tab  34 , and through the opening  40  in the remaining flange  36 , to detachably couple the channel member  26  to the collar  12 . The lower frame  20  may be fabricated using methods and materials well known in the art. 
     Referring to the drawing Figures, the upper frame  18  of the hatch system  10  is provided for retaining the hatch  24 . The upper frame  18  may include a hatch support plate  44  that is coupled to the hatch  24  and affixed to the hinge assembly  22 . The upper frame  18  may also include support members  46  that are affixed to both the support plate  44  and hinge assembly  22 . The support plate  44  is preferably annular and may have a diameter similar to, or slightly greater than, the diameter of the hatch  24 . 
     A plurality of pins  48  are provided to couple the hatch  24  to the support plate  44 . The pins  46  may be affixed to the hatch  24  adjacent to its rim (not shown). The pins  46  extend approximately vertically upward from the hatch  24 , through holes  50  in the support plate  44 , and above a top side  52  of the support plate  44 . 
     Compressible retaining members  54  are provided for lifting the hatch  24  toward a bottom side  56  of the support plate  44 . In the embodiment shown, each compressible member  54  comprises a helical spring  58  fit over a pin  48  and a stop  60  that is affixed to the pin  48  adjacent to its end  62 . The spring  58  is compressed between the stop  60  and the top side  52  of the support plate  44 . The force exerted by compression of the springs  58  tends to lift the hatch  24  toward the bottom side  56  of the support plate  44 . A cover  64  may be fit over each compressible retaining member  54  for protection from the elements. 
     Returning to  FIG. 1 , an inflatable bladder  66  is coupled to the bottom side  56  of the support plate  44  between the hatch  24  and the plate  44 . The bladder  66  may be doughnut shaped and may be fabricated using suitable expandable and resilient materials, such as rubber for example. The bladder  66  may be inflated to overcome the spring force of the helical springs  58  and will tend to force the hatch  24  downwardly from the bottom side  56  of the support plate  44 . This downward force is used to obtain a positive seal between the hatch  24  and the collar  12  of the tank  16 . 
     Referring to  FIG. 1  through  FIG. 3 , and  FIG. 9  (best seen in  FIG. 9 ), the invented hatch system  10  is provided with one or more catches  68  that inhibit the hatch  24  from moving relative to the opening  14  of the tank  16 . The catch  68  may be any suitable configuration that inhibits the hatch  24  from moving relative to the opening  14  and that interlocks the upper and lower frames  18 ,  20  to allow pressure to be applied by the hatch  24  and opening  14 , in order to assure a positive seal between the hatch  24  and collar  12 . The catch  68  may also reduce stresses applied to the hinge assembly  22 . 
     In the embodiment shown, the catch  68  may comprise one or more generally “C” shaped members that are configured to extend about a portion of the lower frame  20 . For example, a catch  68  may comprise a pair of adjacent “C” shaped members  70  that are affixed to each other using know means, such as welding. 
     Each catch  68  may have an end  72  affixed to the support plate  44 , then extend and is generally perpendicular to the plate  44  and down towards the lower frame  20 . The catch  68  may also have a lip  74  that is configured to overlap a portion of the lower frame  20 . The lip  74  of the catch  68  may be configured to overlap a lower edge  76  of the flanges  36 . 
     When the inflatable bladder  66  is inflated, expansion of the bladder  66  tends to force the hatch  24  away from the opening. The lip  74  of the catch  68  may contact the lower edge  76  of the flanges  36  and the channel member&#39;s upper edge  30  may contact the top side  52  of the support plate  44 , thus interlocking the upper and lower frames  18 ,  20 . This may prevent the hatch  24  from moving, thereby trapping the hatch  24  between the tank opening  14  and the upper frame  18 . This allows pressure to be applied by the hatch  24  and to the tank opening  14  in order to assure a positive seal of the hatch  24  and collar  12 . It is to be understood that one or more catches  68  may alternatively be affixed to the lower frame  20  to provide the functionalities of the catches  68  described herein. 
     Referring to  FIG. 5  through  FIG. 7 , the hinge assembly  22  may include a hinge  78  coupling the upper frame  18  to the lower frame  20 , to allow the upper frame  18  to rotate the hatch  24  between an open and closed position relative to the tank&#39;s opening  14 . The hinge assembly  22  may include a means for inflating and deflating the bladder  66 , and a means for rotating the upper frame  18 . 
     In the embodiment shown, the hinge assembly  22  includes a pneumatic piston  80  that is coupled to the upper frame  18  for opening and closing the hatch  24 . A rod  82  of the piston  80  may be pivotably coupled to the hinge  78  and a body of the piston  80  may be affixed to the U-channel  26  of the lower frame  20 . Air lines  86  may be coupled to the piston  80  for actuation thereof. The rod  82  of the piston  80  may be extended when the hatch  24  is in the closed position and may be retracted to open the hatch  24 . 
     An air hose  88  may be coupled to the bladder  66 , via the support plate  44 , at one end  90  and may be coupled to an air source (not shown) at the other end. The air hose  88  provides a gas conduit for inflation and deflation of the bladder  66 . The air lines  86  may be coupled to the piston  80  and the air hose  88  coupled to the support plate  44  using pneumatic fittings known in the art. 
     Referring to the drawings and particularly to  FIG. 2  and  FIG. 4 , an embodiment of a remote control panel  92  is shown for remotely actuating the invented tank hatch system  10 . The control panel  92  is typically positioned at a distance from the hatch  24 , such as near the ground where an operator could easily access the controls of the panel  92 . The remote control panel  92  typically may include controls for actuating the piston  80  to open and close the hatch  24  and for inflating and deflating the bladder  66 . The remote control panel  92  may be configured however desired, such that it provides the features of operation of the hatch system  10  discussed herein. 
     In use, an operator actuates the piston  80  for rotating the upper frame  18  to the open position. The tank  16  may then be filed without obstruction of the opening  14  by the hatch  24 . Once the tank  16  is filled, the operator can then actuate the piston  80  to extend its rod  82  to rotate the upper frame  18  to the closed position. The bladder  66  may then be inflated to force the hatch  24  downward, to form a positive seal between the hatch  24  and opening  14 . 
     When it is desired to open the hatch  24 , the bladder  66  is first deflated. Once the bladder  66  is deflated, the compressible members  54  lift the hatch  24  away from the tank opening  14  at the top of the collar  12 . The upper frame  18 , and thus hatch  24 , may then be rotated away from the opening  14 . 
       FIG. 11  shows an alternative embodiment  10 A of the invented hatch system. In the alternative embodiment  10 A, the upper frame  18  includes a plurality of support members  26 A that extend from the support plate  44  and meet at a center hub  102 . A generally spherical bladder  66 A is coupled to the hub  102  and to a center portion  104  of the hatch  24 . Inflation and deflation of the spherical bladder  66 A is controlled by the remote control  92  as previously discussed. 
     Further, in the alternative embodiment  10 A, one or more catches  106  may be coupled to the lower frame  20 . A lip  108  the catch  106  may overlap the support plate  44  to limit movement of the upper frame  18 , to form a positive seal between the hatch  24  and opening  14 , as discussed above. 
     The above described configuration is provided as an example. The important functionality includes the ability to lift the hatch from the tank opening, then later the ability to press the hatch downward tightly against the tank opening. Therefore, other apparatus configurations that provide this functionality may be useable in the invention. 
     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.