Abstract:
The invention relates to a container for fluids having a volume ( 2   a ) which can be filled with a fluid, and emptied by pressurizing the fluid by subjecting it to internal gas pressure. The invention is characterized in that the container has a valve device ( 7   a ) for filling the volume ( 2   a ) with the fluid, while the internal gas pressure is generated by compressing a gas trapped in the container ( 1   a ). It is thus not necessary to fill the receptacle with pressure gas separately.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is directed to a container or vessel for fluids with a vessel space which can be filled with a fluid and which can be emptied by applying pressure to the fluid via an internal gas pressure. 
     2. Description of the Related Art 
     Vessels of the type mentioned above for fluids, e.g., lubricants or adhesive components, which can be delivered or dispensed by compressed air and which are constructed as large-volume pressure vessels are known. After filling this vessel with the fluid, a valve is fitted and the vessel, which is not completely filled and in which a residual air volume remains, is put under pressure by air. The pressure and the residual air volume are so dimensioned that the vessel can be completely emptied via a rise tube connected with an outlet valve through the expansion of the enclosed air. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to provide a novel vessel for fluids which is improved over the described known fluid vessels, especially with respect to the effort required for filling. 
     The vessel, according to the invention, by which this object is met is characterized by a valve arrangement for filling the vessel space with the fluid accompanied by the generation of the internal gas pressure through compression of a gas enclosed in the vessel. 
     As a result of this inventive solution, the vessel, after being filling, can be completely emptied immediately without additional steps by the internal gas pressure built up in the process of filling the vessel. Separate filling of the vessel with pressure gas is dispensed with. 
     In an embodiment form of the invention, the gas can be compressed in a pressure chamber which can be blocked off from the vessel space. In this case, the internal gas pressure required for emptying the fluid from the vessel space can advantageously remain limited to the pressure chamber which is substantially smaller compared to the total vessel volume. Accordingly, the stored fluid itself is not under pressure and the vessel does not come under the applicable legal regulations for authorization of transport vessels carrying fluid under pressure. Due to the fact that the pressure can remain limited to the small volume of the pressure vessel with a correspondingly small pressure volume product, the strength standards to be met by the vessel space are not as high as those for the vessels known from the prior art which are completely under pressure. The vessel weight can be advantageously reduced because of these less demanding requirements for strength. 
     In a preferred embodiment form of the invention, the valve arrangements are formed by a double valve unit which comprises a filling valve and/or outlet valve and which is provided for closing the filling valve and/or outlet valve while blocking off the pressure chamber from the vessel space, wherein the double valve unit preferably has a closing position in which the pressure chamber is already blocked off from the vessel space and the filling valve and/or outlet valve is still open. In a vessel constructed in this manner, pressure relief in the vessel space is advantageously carried out automatically after the blocking off of the pressure chamber before the vessel space is closed also. The desired pressureless state of the vessel space is achieved in an individual actuation process of the double valve unit in which first the pressure chamber and then the vessel space is blocked off. 
     The double valve unit is preferably to be actuated via a connection piece which can be connected with the filling valve and/or outlet valve, wherein an actuating rod projects into the opening of the filling valve and/or outlet valve for the actuation of the double valve unit, particularly from the connection piece. The sequential closing process mentioned above is effected automatically when the connection piece which is connected, e.g., with a line hose is uncoupled from the filling valve and/or outlet valve. 
     In a further advantageous construction of the invention, it is provided that the double valve unit comprises a pipe piece which extends through the pressure chamber and communicates at one end in a fluid connection with the vessel space, wherein the filling valve and/or outlet valve is arranged at its other end and its pipe wall has at least one valve opening which opens toward the pressure chamber and which can be blocked off by means of a part which is displaceable in the pipe piece by means of actuation of the filling valve and/or outlet valve. The at least one valve opening preferably opens into a conical annular groove of the pipe piece in which a resilient sealing ring which closes the valve opening relative to the pressure chamber in the manner of a spherical valve is arranged and is expandable by means of an actuation part projecting from the valve opening against the displaceable part and the sealing ring for releasing the valve opening. The displaceable part is preferably constructed as an inner pipe which is coaxial to the pipe piece and which has a pipe portion that can rest against the actuation part for releasing the valve opening and a pipe portion with an outer diameter which is reduced relative to the pipe portion. The actuation part is preferably formed by a pressure ball and a plurality of valve openings receiving pressure balls of this type are provided so as to be distributed about the circumference of the pipe piece, wherein the pressure balls are held in the valve openings between the sealing ring and the inner pipe. In an embodiment form of this kind, the valve openings are released as long as the pipe portion of the inner pipe resting against the actuation part ensures that the sealing ring cannot be pressed into its closed position in the annular groove by the internal pressure of the pressure vessel. When the vessel is closed via the filling valve and/or outlet valve, the inner pipe is displaced, so that the portion of the inner pipe with reduced diameter is located opposite the check valve opening and the actuation part can project into the interior space of the pipe piece while closing the valve openings. 
     In a preferred embodiment form in which the pressure vessel and the double valve unit are arranged at the upper side of the vessel, a delivery pipe or rise pipe projecting into the vessel space adjoins the inner pipe. 
     In another embodiment form which is advantageous with respect to manufacture as well as convenience of handling, the vessel space, pressure chamber and double valve unit are arranged coaxial to the longitudinal axis of the vessel. 
     In another preferred embodiment form of the invention, the vessel space is blocked off relative to the enclosed gas by a dividing wall which is movable for compressing the gas and for applying pressure to the fluid. While an internal pressure which is usable for expelling the fluid from the vessel can also immediately build up over the fluid level and expel the fluid from the vessel via the rise pipe, any contact between the fluid and the gas is advantageously prevented by a dividing wall of this kind, so that the fluid cannot be disadvantageously influenced by the gas. Further, no pressure gas can escape when emptying the vessel. 
     In a preferred embodiment form of the invention, the dividing wall is formed by a balloon which is expandable for the compression of the gas or for applying pressure to the fluid inside the vessel. The valve arrangement advantageously comprises a filling valve which opens toward the interior of the balloon, wherein the balloon is constructed in particular in such a way that it can be compressed by the internal gas pressure to virtually zero accompanied by reduction of the volume in the interior of the balloon. In this case, especially when the pressure of the enclosed gas in the empty state of the vessel space exceeds the air pressure acting on the vessel, a fluid contained in the balloon is expelled completely from the vessel while preventing residues. 
     In another advantageous construction of the invention, the filling valve and the balloon are constructed as a constructional assembly which can be mounted on the vessel, wherein the balloon is connected with the filling valve in such a way that it can be introduced into the vessel through a valve opening which is provided at the vessel and which, for example, is provided with a thread, wherein the filling valve provided with an external thread is then screwed into the thread of the opening. 
     The invention will be explained and described more fully with reference to an embodiment example and the accompanying drawings relating to this embodiment example. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 shows a fluid vessel according to the invention in vertical section; 
     FIG. 2 shows a double valve used in the vessel shown in FIG. 1 in a closed position; 
     FIG. 3 shows the double valve from FIG. 2 in an opened position; and 
     FIG. 4 shows another embodiment example for a fluid vessel according to the invention in vertical section. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A substantially round-cylindrical vessel with rounded end faces, designated by reference number  1  in FIG. 1, is divided into a vessel space  2  and a pressure chamber  3 . In the embodiment example shown, the volume of the vessel space is  25  l and the volume of the pressure chamber is  5  l. The cylindrical wall projects over the vessel end faces at both ends of the vessel  1 , wherein a steel ring  4  and  5 , respectively, is arranged at each end edge. 
     Below the ring  5 , the projecting cylindrical wall has recesses, not shown, affording gripping possibilities for handling the vessel by grasping around the steel ring  5 . 
     A double valve unit, designated by reference number  13  in FIG. 1, has a pipe piece  6  which is guided through the pressure chamber  3 . A filling/outlet valve  7  is arranged at the end remote of the vessel space  2  in the pipe piece  6  opening toward the vessel space  2 . The pipe piece  6  further has, in its pipe wall, valve openings  8  and  9  which open into the pressure chamber  3  and which are described more precisely with reference to FIGS. 2 and 3. An inner pipe  11  which is connected with the valve  7  via a pin  10  is arranged inside the pipe piece  6  and is displaceable against the pipe piece  6 . The inner pipe  11  having portions with diameters of different size is connected with a rise pipe  12  which projects into the vessel space  2 . 
     Reference is had now to FIGS. 2 and 3 in which the double valve unit  13  is described more exactly. Identical parts are designated in FIGS. 2 and 3 by the same reference numbers used in FIG.  1 . 
     As will be seen from FIGS. 2 and 3, the filling/outlet valve  7  has a sleeve part  14  which is received in a seat or receptacle  15  formed in the pipe piece  6  by a widening of the inner diameter and is sealed relative to the pipe piece  6  by a ring seal  16 . Valve parts  19  and  20  which are displaceable in the direction of the longitudinal axis coaxial to the longitudinal axis of the sleeve against helical springs  17  and  18  are arranged in the sleeve part  14 . In the closed state shown in FIG. 2, the valve part  20  rests against the sleeve  14  by an annular projection  21  and is sealed relative to the seal  14  by a ring seal  22 . In this state, the valve part  19  having through-openings rests against the sleeve part  14  by a sealing ring surface  23 . 
     As will further be seen in FIGS. 2 and 3, the helical springs  17  and  18  rest against a support plate  24  arranged in the sleeve  14  by their ends remote of the valve part  19  and  20 , respectively. The support plate  24  has a central guide opening for the pin  10  which is connected with the valve part  20  and the inner pipe  11 . 
     A flexible seal ring, designated by reference number  26  in FIG. 3, is seated in a conical annular groove extending about the pipe piece  6  and closes the valve openings  8  and  9  opening toward the annular groove  25  in the manner of a ball valve. The valve openings  8  and  9  are representative of a plurality of valve openings of this type which are distributed about the circumference of the pipe piece  6 . Pressure balls  27  which rest against the sealing ring  26  and project over the inner pipe  11  are arranged in the valve openings, wherein the pressure balls are held in the valve opening by the sealing ring  26  and the pipe piece  11 . 
     As will be seen clearly with reference to FIGS. 2 and 3, the inner pipe  11  has portions  29  and  30  with different diameters, wherein the portion  29  with the greater diameter is formed in the pipe piece  6  and a transition portion  28  extending at an inclination to the longitudinal axis of the pipe is formed between the portions. The diameter of portion  30  is reduced relative to portion  29  to the extent that the rotating balls  27  can project into the interior of the pipe piece  6  until the sealing ring  26  rests circumferentially in the conical annular groove  25  and closes the valve openings. 
     In FIGS. 2 and 3, seal rings are designated by reference numbers  31  to  33 , wherein a double valve unit  13  is sealed relative to the sleeve parts  34 ,  35  connected with the wall of the pressure chamber  3 . 
     The inner pipe  11  is provided with a two-part seal ring  36  whose outer part having a strip cross section is made from a plastic-bronze mixture with good sliding properties. 
     The manner of operation of the fluid vessel described in FIGS. 1 to  3  will be described in the following. 
     In order to fill the vessel, a connection piece, not shown in the Figures, which is connected, e.g., with a hose line, is arranged at the sleeve part  14 , and presses the valve part  20  into the sleeve part  14  into the position shown in FIG. 3 against the pressure of the helical spring  18  by means of a projecting rod. During this displacement, the annular projection  21  comes into contact against the valve part  19  which is likewise displaced against the force of the helical spring  17 , wherein the sealing ring surface  23  is distanced from the wall of the sleeve part  14  while releasing the opening gap. Along with the displacement of the valve part  20 , the inner pipe  11  is also displaced via pin  10  into the position shown in FIG. 3 in which the inner pipe  11  comes into contact against the pressure balls  27 , first with the transition portion  28  and then with the widened portion  29 , and expands the sealing ring  26 , so as to prevent a closing of the valve openings by internal pressure of the pressure chamber  3  acting on the sealing ring  26 . 
     In this open position of the double valve unit  13  shown in FIG. 3, the vessel is first placed under low gas pressure (e.g., 0.7 bar) via the connection piece (not shown) and the vessel is then filled with a fluid, e.g., a lubricant or a component of an adhesive, via this connection piece, wherein the fluid reaches the vessel  2  through the sleeve part  14 , the pipe piece  6 , the inner pipe  11  and the rise pipe  12  connected thereto. 
     As the level of fluid rises, the gas which is enclosed in the vessel and which can be suitably selected, e.g., corresponding to the type of fluid is compressed and reaches the pressure chamber  3  via the intermediate space formed between portion  30  of the inner pipe  11  and pipe piece  6  and via the valve openings ( 8  and  9 ), wherein the internal pressure increases as the liquid level rises. 
     When the vessel space  2  is filled, i.e., the liquid level reaches the pressure chamber  3 , the filling/outlet valve  7  is automatically closed with the removal of the connection piece, not shown, in that the valve parts  19  and  20  are displaced into the position shown in FIG. 2 by the springs  17  and  18 . Accordingly, a displacement of the inner pipe  11  is also carried out via the pin  10 , wherein the portion  30  of the inner pipe  11  having the smaller diameter now makes it possible for the pressure balls  27  to project into the interior of the pipe piece  6  until the valve openings ( 8  and  9 ) are closed via the sealing ring  26  under the influence of the internal pressure in the pressure chamber  3 . 
     Immediately after the closing of the valve openings  8  and  9  and before the closing position shown in FIG. 2 is reached, the filling/outlet valve  7  is not yet closed, so that gas under pressure remaining in the vessel space  2  can escape outward through the filling/outlet valve. When the filling/outlet valve  7  is then completely closed, the vessel space  2  is no longer under pressure. Only the substantially smaller pressure vessel  3  is still acted upon by pressure. 
     The vessel can now be loaded for transport, for example, wherein a steel ring  4  ensures that the vessel will stand securely on a loading base. 
     To empty the vessel at a desired location, a connection piece of a hose line is connected to the filling/outlet valve  7  in the same manner as when filling, wherein, as was already described above, the valve openings ( 8  and  9 ) are also opened in addition to the valve  7 , so that the gas pressure present in the pressure chamber  3  contacts the surface of the liquid stored in the vessel via the valve openings  8  and  9  and the intermediate space between the inner pipe  11  and the pipe piece  6  and the liquid presses outward through the rise pipe  12 , inner pipe  11 , pipe piece  6  and valve  7 . 
     The initial gas pressure or pre-pressure generated in the vessel before the vessel is filled is dimensioned in such a way that it is ensured that the liquid stored in the vessel space  2  will be removed in its entirety from the vessel. 
     Reference is had now to FIG. 4 which shows another embodiment example for a vessel according to the invention. Identical or identically working parts are designated by the same reference numbers as in the embodiment example shown above, but with the addition of the letter a. The relevant parts are therefore not described in more detail. 
     The embodiment example shown in FIG. 4 differs from the preceding embodiment example in that, instead of the double valve unit  13 , only a filling/outlet valve  7   a  is provided which can be screwed into a threaded projection  40  at the valve opening of a vessel  1   a.    
     The filling/outlet valve  7   a  is connected with a rubber balloon  41  arranged coaxial thereto, wherein the vessel interior is divided by the rubber balloon  41  into the vessel space portion  2   a  which is usable for filling with a fluid and a vessel space portion  42 . The volume ratio between the vessel space portions  2   a  and  42  can be changed by means of the expandability of the rubber balloon  41 . 
     A valve by means of which the vessel space  42  can be filled with a pressure gas is designated by  43  in FIG.  4 . 
     In order to prepare the vessel shown in FIG. 4 for operation, a pressure gas, e.g., air, is introduced via the valve  43  with the balloon  41  completely emptied and the valve  7   a  open, wherein, in the embodiment example shown, a pressure greater than 0.7 bar is generated in the vessel. For this purpose, the balloon  41  is compressed, so that its internal volume is almost equal to zero. 
     The vessel which is provided with a pre-pressure, can now be filled with a liquid via the filling/outlet valve  7   a , wherein the balloon  41  expands and the pressure gas in the vessel space portion  42  is compressed. In the embodiment example shown, the vessel which is produced from a resilient rubber material expands until the liquid filling pressure is equal to the gas pressure generated in the reduced vessel space portion  42 . In the embodiment example shown, this liquid filling pressure is approximately 7 bar. The volume of the vessel space portion  42  was reduced in a corresponding manner to one tenth of the volume in a completely compressed balloon  41  and the majority of the vessel volume is now consequently filled with liquid. 
     The tightness of the vessel  1   a  is sufficiently high so that the liquid, e.g., for purposes of transport or storage, can remain in the vessel for a long period of time without pressure loss. 
     In order to empty the vessel, a connection piece is arranged at the filling/outlet valve  7   a , which connection piece opens the latter when connected. The balloon  41  is now compressed by the internal gas pressure while the vessel  1   a  is emptied, wherein it is ensured by means of the suitably selected pre-pressure that the vessel volume  2   a  is brought approximately to the value of zero accompanied by an almost complete expulsion of the fluid from the vessel. 
     The liquid stored in the vessel does not come into contact with the surrounding atmosphere either during the filling process or during the emptying process, so that liquids stored and transported in the vessel cannot be impaired in any way. 
     The balloon  41  connected with the valve  7   a  can be removed from, i.e., pulled out of, the vessel together with the valve  7   a  when it is necessary to exchange or clean the balloon  41 , for example, after a determined operating period or when the liquid to be stored in the vessel is changed.