Abstract:
The invention relates to a fluid reservoir for a paint spray gun, comprising a receptacle ( 1 ) and a lid that can be placed thereupon and is provided with a connecting element ( 3 ) in order to mount the fluid reservoir on the paint spray gun or an adapter. The receptacle ( 1 ) is provided with a ventilation hole ( 4 ) which can be sealed using a valve. In order to improve the tightness of the valve, said valve encompasses two valve seats for sealing the ventilation port ( 4 ), which are disposed one behind another in the direction of flow.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates to a fluid reservoir for a paint spray gun.  
       BACKGROUND OF THE INVENTION  
       [0002]     Such a fluid reservoir is known from prior art, for instance, WO 98/32539. This fluid reservoir is provided for one time use and comprises a container of plastic and a lid that can be placed thereon to close off the container. On the lid, connecting means are provided for placing the fluid reservoir on and fastening it to a paint spray gun or an adapter mounted thereon. In this case, the fluid reservoir is placed “upside down” on the paint spray gun, i.e., with lid side down. The paint present in the fluid reservoir then flows by gravity downwards into the paint inlet channel of the paint spray gun. In order to allow the gravity driven flow of paint, it is necessary for the pressure in the interior and that in the environment to be equalized. In order to guarantee this equalization, a ventilation part that can be closed by means of an adhesive tape or a manually operable valve is made in the container&#39;s bottom.  
         [0003]     All the devices from prior art for closing the ventilation part have proved inadequate with regard to their tightness. Even with a valve mechanism, it cannot be reliably assured that paint will not escape through the ventilation part when the paint filled fluid reservoir is set down on its base.  
         [0004]     Starting from this point, the invention is based on the problem of refining the fluid reservoir as known from prior art such that a flow of paint through the ventilation part is reliably prevented.  
       SUMMARY OF THE INVENTION  
       [0005]     This problem is solved by fluid reservoir with the characteristics of Claim  1 . Advantageous refinements of this fluid reservoir can be deduced from the subordinate claims.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     The invention will be explained in detail below on the basis of one embodiment with reference to the appended drawing. The drawings show:  
         [0007]      FIG. 1 , oblique side view of a fluid reservoir according to the invention;  
         [0008]      FIG. 2 , oblique representation of the container of the fluid reservoir according to the invention from  FIG. 1 , in a view from obliquely below;  
         [0009]      FIG. 3 , detail view of area Y from  FIG. 2 ;  
         [0010]      FIG. 4 , sectional representation of a valve for closing the ventilation part in the receptacle bottom of the fluid reservoir from  FIG. 2 , wherein the valve is shown in the closed position in  FIG. 4 ( a ) and in the opened position in  FIG. 4 ( b );  
         [0011]      FIG. 5 , side view of the fluid reservoir according to the invention, wherein the receptacle is represented in cross section and detail views of areas X and Y are shown;  
         [0012]      FIG. 6 , sectional representation of the fluid reservoir of  FIG. 1  in the area of the lid;  
         [0013]      FIG. 7 , top view onto an alternative embodiment of a valve for closing the ventilation part in the receptacle bottom ( FIG. 7   a ) and sectional representations of this alternative embodiment along line A-A ( FIG. 7   b ) and along line B-B ( FIG. 7   c ), wherein the valve is shown in the opened position;  
         [0014]      FIG. 8 , representation of the alternative embodiment of the valve, shown as in  FIG. 7 , but in the closed position of the valve. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     As shown in  FIG. 1 , the fluid reservoir according to the invention comprises a cup shaped receptacle  1  and a lid  2  that can be screwed onto it by way of a thread  19 . Thread  19  formed on the upper rim of receptacle  1  for screwing lid  2  on is recognizable in  FIG. 2 . On its upper side, lid  2  has an outlet neck  20  with an outlet opening  19 , not shown in  FIG. 1 . A connecting element  3  is formed on the outer side of outlet neck  20 . Connecting element  3  serves for placing and fastening the fluid reservoir on a paint spray gun or on an adapter arranged between the paint spray gun and the fluid reservoir. In the embodiment shown in the figures, connecting element  3  comprises a thread  21  and a wedge shaped groove  22  that cooperate with corresponding connecting elements of the paint spray gun, namely a matching inside thread and a pin for engagement in groove  22 .  
         [0016]     Receptacle  1  is cup shaped with a circular receptacle bottom  23  and sidewall  24  opening upward slightly conically, as is evident from  FIG. 2 .  
         [0017]     The fluid reservoir is shown in a side view in  FIG. 5 , wherein receptacle I is shown in section. The central area of receptacle bottom  23  is shown in detail view X of  FIG. 5 . A hollow cylindrical projection  10 , wall  29  of which projects vertically outward from receptacle bottom  23 , is formed on receptacle bottom  23 . Projection  10  is integral with receptacle bottom  23 . Central axis A of hollow cylindrical projection  10  is arranged concentrically to the central axis of receptacle  1 . A ventilation part  4  is formed in receptacle bottom  23 , likewise concentrically to axis A. Ventilation part  4  is enclosed by an annular wall  8 . A radially running annular rib  17  is formed on outer side  9  of wall  29 . It is evident from the representation of  FIG. 3  that a plurality of depressions  18 , which are arranged segment by segment in the radial direction with a distance between one another, are provided in outer side  9 . Depressions  18  extend axially from upper edge  30  of projection  10  to roughly half the height of projection  10  ( FIG. 4 ). Openings can also be provided instead of depressions  18 .  
         [0018]     As is illustrated in  FIG. 5 , two closure elements  5  are formed onto lid  2 , each via pull off tabs  25 . Pull off tabs  25  are formed as predetermined breakage points so that closure elements  5  can be torn manually away from lid  2  without the aid of tools. Closure elements  5  are each identical to the other, and serve to close ventilation part  4  on the one hand and to close outlet opening  19  on the other.  
         [0019]     As is evident from detail view Y in  FIG. 5 , closure element  5  has a hollow cylindrical base body  11  and a lid  26  formed integrally with it. In a central area, lid  26  is indented into the interior of base body  11 , that is, downwards in the detail view Y of  FIG. 1 , in order to form a plug  12 . A stopper  13  tapering conically downwards is formed on the underside of this plug  12 . The underside  27  of stopper  3  projects past lower edge  28  of base body  11 . Two annular grooves  15  and  16 , running parallel and apart from one another, are formed on the outer side of hollow cylindrical base body  11 .  
         [0020]     One of the two closure elements  5  cooperates with projection  10  to form a valve for closure of ventilation part  4 , with projection  10  projecting from receptacle bottom  23  forming the housing and closure element  5  forming the valve cover. The valve is constructed here as a double seat valve, with two valve seats arranged one after the other in the direction of flow and separated from one another. Each valve seat has its own sealing surface,  6  and  7 , respectively. The cooperation of closure element  5  and projection  10  to form the valve with which ventilation part  4  can be closed off is shown in detail in  FIG. 4 . For this purpose, closure element  5  is pushed over projection  10 , so that hollow cylindrical base body  11  embraces the cylindrical wall of projection  10 . In order to guarantee a tight contact of closure element  5  on projection  10 , the inside diameter of hollow cylindrical base body  11  and the outer diameter of hollow cylindrical projection  10  are roughly equally large.  
         [0021]     The valve formed by closure element  5  and projection  10  can be fixed in two valve positions by cooperation of grooves  15  and  16  on the inner side of base body  11  and annular rib  17  on the outer side of projection  10 . In the valve position shown in  FIG. 4 ( a ), annular rib  17  engages with upper annular groove  15  and lower edge  28  of hollow cylindrical base body  11  rests on receptacle bottom  23 . At the same time, stopper  13  engages with ventilation part  4 . The outer surface of stopper  13  rests tightly against wall  8  of ventilation part  4  in this case. In this manner, a first valve seat with a first sealing surface  6  is formed. At the same time, a second sealing surface  7  separated from first sealing surface  6  is formed by virtue of the fact that the inner side of base body  1 I rests tightly against outer wall  9  of hollow cylindrical projection  10 . In this valve position, ventilation part  4  is tightly closed by the first valve seat (which is formed by the engagement of stopper  13  with ventilation part  4 ) on the one hand and, on the other, by way of the second valve seat (which is formed by the contact of inner side  14  of base body  11  with the lower periphery of outer wall  9 ). If a small amount of paint were to flow out of ventilation part  4  through the first valve with first sealing surface  6 , the further flow of paint out of receptacle  1  is prevented by the second valve seat.  
         [0022]     To open ventilation part  4 , closure element  5  can be brought into a second valve position, as illustrated in  FIG. 4 ( b ). For this purpose, the closure element is raised upwards, that is, away from receptacle bottom  23 , until annular rib  17  engages with lower annular groove  16  ( FIG. 4 ( b )). To facilitate this raising of closure element  5  from the first to the second valve position and to detach the initial seating of annular rib  19  in upper annular groove  15 , it is advantageous for lid part  26  of closure element  5  to project laterally past base body  11 . On the one hand, an easier gripping of the closure element on lid  26  is made possible thereby, and on the other, the engagement of annular rib  17  in upper annular groove  15  of lid  26  can be released, because the inside diameter in the area of base body  11  is enlarged by bending this projecting part of lid part  26  upwards.  
         [0023]     In the second valve position shown in  FIG. 4 ( b ), stopper  13  is disengaged from ventilation part  4  so that the latter is opened up. At the same time, the second valve seat is also released, since lower edge  28  of base body  11  lies in the area of depressions  18  on the outer side of projection  10  in this valve position, as is evident from  FIG. 4 ( b ), right side. In this position, it is possible for air to pass from the interior of receptacle I through ventilation part  4  and through the passageway formed between depressions  18  and inner side  14  of base body  11 .  
         [0024]     The second closure element  5  formed on lid  2 , which is formed identically to the other closure element  5 , can be used for closing off outlet opening  19  on the connecting element of lid  2  in that this closure element  5  is first broken off lid  2  and then placed on outlet neck  20 . The inside diameter of base body  11  and the outside diameter of outlet neck  20  are matched to one another for this purpose, so that inner side  14  of base body  11  rests tightly against the outer side of neck  20 , as shown in  FIG. 6 .  
         [0025]     Another embodiment of a valve for closing off ventilation part is illustrated in  FIG. 7 .  FIG. 7   a  shows a top view of this valve which, just like the above described valve, has two valve seats arranged one behind the other in the direction of flow. Identical components of this valve are furnished with the same reference numbers as in FIGS.  3   5 . As in the embodiment shown in those figures, projection  10  also forms the valve housing in the valve shown in  FIG. 7 , and a closure element  5  forms the valve cover. The valve is likewise constructed as a double valve with two valve seats separated from one another, each valve seat having its own sealing surface  6  and  7 , respectively. Closure element  5  is pushed over projection  10  such that it grips it, with hollow cylindrical base body  11  embracing the cylindrical wall of projection  10 . In the center, closure element  5  has a cylindrical stopper  13 , which engages with ventilation part  4  in the closed valve position and forms first sealing surface  6  there. Second sealing surface  7  is again formed on outer wall  9  of projection  10 , where inner surface  14  of closure element base body  11  rests against it.  
         [0026]     Unlike the embodiments of  FIGS. 3-5 , closure element  5  shown in  FIG. 7  is not seated on projection  10  via an engagement mechanism, but rather grips it. Closure element  5  can be displaced between a first limit position and a second limit position, with the valve being opened in the first limit position, as shown in  FIGS. 7   a  and  7   b,  and closed in the second limit position, as shown in  FIGS. 8   a  and  8   b.  An annular rib  17   a  is formed on the outer side of projection  10 . An annular groove  15   a  in closure element  5 , which cooperates with annular rib  17   a  to form two stops in the first and second valve position, is provided on the inner surface of hollow cylindrical base body  11 . In the valve position shown in  FIG. 7 , the lower edge of annular groove  15   a  rests against annular rib  17   a,  and in the closed valve position shown in  FIG. 8 , the upper edge of annular groove  15   a  rests against annular rib  17   a.  Between these two positions, closure element  5  is displaceable relative to projection  10 .  
         [0027]     In an embodiment of the fluid reservoir not represented graphically here, it is provided that ventilation part  4  is first closed off by a thin membrane, and is then punctured into the first valve position only upon insertion of closure element  5  by pushing a sharp point formed on stopper  13  of closure element  5  through the thin membrane.  
         [0028]     Due to the formation of two separate valve seats, each with a sealing surface  6  or  7 , respectively, a tight closure of ventilation part  4  becomes possible with the fluid reservoir according to the invention. This closure is distinguished from measures for closing off the ventilation part in the container&#39;s bottom that were known from prior art by better leak tightness. Ultimately this makes it possible to set the container on the floor without paint present in the container leaking out. It is thereby made possible, in particular, to mix paint in the container before the container is then placed in the usual manner on the paint spray gun. The valve for closing off the ventilation part is further distinguished by the fact that closure element  5  can easily be removed manually from the container by pulling it off after undoing the snap connection. This makes it possible for excess paint that was not consumed in the painting process to flow out of ventilation part and be recycled if the container is held with the receptacle bottom facing downwards.  
         [0029]     In an alternative embodiment, not shown graphically here, ventilation part  4  and projection  10  surrounding it is situated eccentrically relative to the longitudinal central axis of receptacle  1 , i.e., ventilation part  4  as well as central axis A of projection  10  are eccentric relative to receptacle bottom  23 .  
         [0030]     Furthermore, the valve for closing off ventilation part  4  can be constructed such that it can be set to more than two valve positions. For this purpose it is provided, for instance, that more than two annular grooves  15 ,  16  are arranged on the outer side of hollow cylindrical base body  11 . As an alternative to a plurality of annular grooves for forming a valve that can be locked in several positions, it is also possible for double annular grooves to be formed in parallel and with a distance between one another.