Abstract:
A valve device for filling containers, particularly containers intended to contain liquefied gases, includes a valve body in which a gas duct is defined at the inlet of the container, the gas duct extending predominantly in an axial direction. A closure is axially movable in the valve body away from and towards a valve seat in order, respectively, to open and shut off the gas duct. A float type actuator, capable of exerting a thrust on a second end of the closure, is provided. A deflector cover is disposed transversely to the gas pipe and is integral with the valve body. The deflector includes a guide cavity in which a first end of the closure is slidably engaged.

Description:
BACKGROUND 
       [0001]    1. Technical Environment 
         [0002]    The object of the present disclosure is a valve device for filling containers, in particular containers intended to contain liquefied gases. 
         [0003]    2. Prior Art 
         [0004]    Such containers, better known as “cylinders,” are widely utilized where a connection to the distribution network for fuel gases has not been provided. 
         [0005]    For financial and safety reasons it is best that the cylinders should be filled with a predefined maximum quantity of gas, avoiding overfilling and thus excessive internal pressure. For this reason the cylinders are equipped with devices for preventing overfilling, sized to cut off the flow of entering gas when a desired fill level has been reached. 
         [0006]    Devices of the type described above are known, for example, to the production of the Applicant and comprise membrane valves. Such valves are of the type that is normally closed and comprise a perforated membrane in the center, which, becoming deformed under the action of the entering gas, permits its passage. The gas flow is intercepted when a prearranged level of filling is reached and a piston, placed below the membrane and actuated by a cam connected to a float inside the container, thrusts against a seat, closing one section for passage of the gas. The variation of the sections for passage causes a counter-pressure that acts on the membrane in a direction opposite to that of the gas entering the container, closing the entrance orifice. 
         [0007]    The disadvantages of such solutions are those typical of the applications of valves to membranes, i.e., the greater predisposition to wear and tear and the consequent lesser reliability compared to solutions that use valves in which the closure means is a rigid component. 
         [0008]    Another inconvenience encountered in the specific application of the valve device for filling cylinders is represented by the fact that the membrane valve thus conceived makes it difficult to produce a vacuum inside the container. 
         [0009]    A further drawback encountered is the reduction of the capacity of exiting gas during normal use. 
         [0010]    Devices for filling cylinders that employ valves without membranes are known, for example, from the American patent U.S. Pat. No. 4,541,464. In this solution the valve is spherical, normally open. The obstructing sphere is kept in the open position by means of a pin constructed on a spherical member connected to a float by means of a cam driver. During the filling operation the float comes out of the container so that it causes the spherical member to rotate by means of the driving action of the cam. The system is sized in such a way that when the filling position is reached, the rotation of the spherical member causes a loss of contact between the pin and the sphere, which is thrust into the closed position of the valve by the force of gravity, besides a possible return spring. 
         [0011]    A principal drawback of such solutions is represented by the fact of its being sensitive to the inclination and the oscillations of the cylinder, also from the moment that the spherical member rotates as an effect of any kind of deviation of the cylinder&#39;s axis from the vertical position. 
         [0012]    A further problem with this solution is determined by the number of elements that compose it and the use of spherical members that complicate the operations of construction and assembly, making the device particularly sensitive to size tolerances and coupling. For the same reasons, the reliability of this solution in use is limited. 
       DESCRIPTION OF THE INVENTION 
       [0013]    The main purpose of the invention is to make available a valve device for filling containers, in particular containers intended to contain liquefied compressed gas, structurally and functionally conceived so as to avoid all the drawbacks complained of with reference to the prior art cited. 
         [0014]    This and other purposes that will appear in what follows are confronted and achieved by the invention by means of a valve device for filling containers accomplished in accordance with the claims that follow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The characteristics and advantages of the disclosure will be better shown by the following detailed description of a preferred example of the device, illustrated by way of example but not limitative, with reference to the units drawn in which: 
           [0016]      FIG. 1  is a lateral view of a device for preventing overfilling according to the present invention; 
           [0017]      FIG. 2  is a frontal-section view of the device of  FIG. 1 ; 
           [0018]      FIG. 3  is a lateral-section view of a constructible variant of the device of  FIG. 1 ; 
           [0019]      FIG. 4  is a sectional lateral view of the device in  FIG. 2 , in a different operating state of the device of the present invention. 
       
    
    
     PREFERRED MODE OF ACTUATING THE INVENTION 
       [0020]    In the figures,  1  is a comprehensive indication of a device for preventing overfilling of containers according to the present invention. Device  1  is intended to be applied to a container (cylinder B) for liquefied gas under pressure. Device  1  comprises an upper channel  2  which has a longitudinal axis Y, connected to the pipe union for supplying and filling of cylinder B. 
         [0021]    Below channel  2 , device  1  comprises a valve device  3   a , below which is installed a lower channel  4  with axis X orthogonal to axis Y, connected with an internal volume V of the cylinder, of known cylindrical form with rounded bottoms, intended to collect the liquefied gas stored in cylinder B. 
         [0022]    Valve device  3   a  comprises a valve body  3 , interposed between channels  2  and  4 , in which is defined a gas duct  5  entering the cylinder, extended mainly along the direction of axis Y. The gas duct  5  is delimited, in the directions transversal to axis Y, by an internal surface  6  of valve body  3 . 
         [0023]    Valve device  3   a  comprises a rigid closure means  7  having the shape of a truncated cone, on axis Y with the tapered part turned toward channel  4 , axially movable in valve body  3  from and toward a valve seat  8  in order to respectively open and intercept gas duct  5 . 
         [0024]    According to a constructible variant ( FIGS. 2 and 4 ), on valve seat  8  is provided an annular rubber gasket, as a seal between valve body  3  and valve seat  8  when gas duct  5  is intercepted. According to another constructible variant, annular gasket  400  is linked to closure means  7 . 
         [0025]    Closure means  7  comprises a first upper extremity  9 , in the form an appendix having a circular base and longitudinally extended along axis Y. Appendix  9  rises from a base surface  7   a  of closure means  7 , turned toward channel  2 , and is equipped with a terminal surface  9   a.    
         [0026]    Valve device  3   a  furthermore comprises a deflecting cover  10 , placed transversally to gas duct  5  and comprising a guide cavity  11  for closure device  7 , turned toward channel  4  and equipped with a circular border  11   a . At the bottom of cavity  11  there is a first cylindrical guide surface  100 , having axis Y, on which is smoothly integrated appendix  9 . In cavity  11  is a second cylindrical surface  200 , this also with axis Y, interposed between first cylindrical surface  100  and border  11   a  of cavity  11 . On cylindrical surface  200  is smoothly bound the perimetral border  7   b  of base  7   a  of closure means  7 . 
         [0027]    Between border  7   b  of base  7   a  of closure means  7  is cylindrical surface  200  and interposed an annular gasket  300 , integrated into border  7   b , which serves as a seal for preventing the passage of gas from gas duct  5  toward surface  9   a  and base  7   a . According to a constructible variant of the invention, annular gasket  300  can be linked to base  7   a  and not to border  7   b.    
         [0028]    Between appendix  9  and cylindrical surface  100  is interposed an annular gasket  500 , integrated into appendix  9 , which serves as a seal for preventing the passage of gas from gas duct  5  toward surface  9   a . According to a constructible variant of the invention, annular ring  500  can be linked to cylindrical surface  100  and not to appendix  9 . 
         [0029]    According to other constructible variants of the invention, a single gasket is used, in one of the two above described positions for gaskets  300  and  500 . 
         [0030]    According to a constructible variant of the invention, between border  7   b  of base  7   a  of closure means  7  and cylindrical surface  200  no gasket is interposed, the seal being guaranteed by the sliding contact between border  7   b  and cylindrical surface  200  ( FIG. 3 ). 
         [0031]    Valve seat  8  is located, with respect to gas duct  5 , below annular gasket  300 . 
         [0032]    Deflector lid  10 , on the side axially opposite to cavity  11 , comprises a central arch  12 , capable of being entered by the flow of gas entering the cylinder. Deflector lid  10  is integral to valve body  3 , being equipped with a perimetric annular protuberance  13 , partially nested in an annular seat  14 , located on the inner surface  6  of valve body  3 . 
         [0033]    Annular protuberance  13  is transverse to axis Y and is provided with a plurality of passages  15 , to allow for the flow of entering gas to valve seat  8 . 
         [0034]    In correspondence to a second extremity, axially opposite with request to appendix  9 , closure means  7  comprises a control rod  17 , longitudinally extended along axis Y. 
         [0035]    Control rod  17  crosses channel  4 , above which it is bound in a cylindrical axial guide  18 , integral to valve body  3  and working together with guide cavity  11  to axially guide closure means  7 . Control rod  17  furthermore comprises an end  19 , axially opposite closure means  7 . 
         [0036]    Device  1  comprises an actuator  16  that can exert a thrusting force F on end  19  of rod  17  in order to urge closure means  7  away from valve seat  8 . 
         [0037]    Actuator  16  comprises a float  20 , extended inside the interior volume V of cylinder B, and a cam mechanism  21  to exert the thrust F, in a rising phase of float  20 . Thrust F is exerted until it reaches an extreme position preset by float  20 , corresponding to a maximum fill level of cylinder B. 
         [0038]    Mechanism  21  comprises a member  22 , linked to valve body  3  by a hinge  23 , on which a cam profile  24  is defined. Cam profile  24  is compatible with closure means  7  in order to exert thrust F until it meets end  19  of control rod  17 . During the ascending phase of float  20 , end  19  of rod  17  slides on cam profile  24  until it reaches an end point  25  ( FIG. 4 ). 
         [0039]    Cam profile  24  is an arc of a circle with its center on the axis of hinge  23  so as to hold closure means  7  at a constant distance from valve seat  8 . Cam profile  24  is sized in such a way that when float  20  has reached the extreme position of maximum filling, end  19  is placed in correspondence with point  25 . In this state, thrust F cannot be exerted, and closure means  7  thus becomes subject only to its own force weight P, which causes closure means  7  to fall toward valve seat  8  so as to intercept gas duct  5 . 
         [0040]    According to a constructible variant (not shown) of the present invention, the fall of closure means  7  is caused, in addition to weight P, by a return spring. 
         [0041]    Actuator  16  furthermore comprises a lever mechanism  26  for exerting thrust F on rod  17  in a first stage of descent of float  20  starting from its extreme point of maximum filling. 
         [0042]    Lever mechanism  26  comprises a fulcrum  27 , hinged to member  22  at distance D from hinge  23 , and a first arm  28  extended from fulcrum  27  toward cam profile  24 . First arm  28  [is] compatible with closure means  7  for exerting thrust F, until it meets end  19  of control rod  17  and a second arm  29 . Fulcrum  27  is interposed between first arm  28  and a second arm  29 , integral to float  20 . First arm  28  and cam profile  24  are positioned from the same part with respect to straight line Z, which joins hinge  23  and fulcrum  27 . 
         [0043]    During the ascending phase of float  20 , arms  28  and  29  place themselves in a position aligned with member  22 , in such a way that first arm  28  can rest against member  22 . 
         [0044]    During the descending phase of float  20 , end  19  of rod  17  slides on first arm  28  until it reaches an end  30  of first arm  28  in correspondence with an intermediate position of float  20 . 
         [0045]    In correspondence with the intermediate position of float  20 , the point of end  25  of cam profile  24  and end  30  of first arm  28  are adjacent to each other. Besides the intermediate position, in a second part of the ascending phase of float  20 , end  19  of rod  17  moves on cam profile  24 . 
         [0046]    The functioning of lever mechanism  26  described above thus permits the rearming of cam mechanism  21 , in such a way that end  19  of rod  17  can move on cam profile  24  when the level of cylinder B is lower than the intermediate one, in particular when cylinder B is empty. 
         [0047]    According to other variants of the present invention (not shown), in place of actuator  16 , other types of float actuators can be used, provided that they are able to keep closure means  7  open until cylinder B is completely filled 
         [0048]    The present invention allows us to produce a valve device for filling containers comprising a valve that does not use closure means involving membranes and of a type that is always open. 
         [0049]    The reduced number of other valve components, compared to other known solutions, permits the achievement of greater simplicity in the functional geometries and, consequently, fewer rejects in production and greater dependability in usage. 
         [0050]    The use of a valve that is always open allows better performance in relation to the implementation of the vacuum in the cylinders.