Abstract:
Manually operated invertible pump for dispensing atomized liquids, the pump having a very compact structure and an aperture which can be intercepted by the pump piston to control liquid entry into the pump when this is in a downwardly inverted position.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a manually operated invertible pump for dispensing atomized liquids withdrawn from a liquid container, on the mouth of which the pump is mounted usable both in the upright position, i.e. with the pump facing upwards from the container, and in the inverted position, i.e. with the pump facing downwards from the container.  
       BACKGROUND OF THE INVENTION  
       [0002]     Many types of invertible pumps are known, such as those described in U.S. Pat. No. 5,222,636, U.S. Pat. No. 4,775,079, U.S. Pat No. 4,277,001, U.S. Pat. No. 5,738,252, EP-A-0648545 and EP-A-1029597, however such pumps have serious drawbacks which limit their production and use. In this respect, some are of very complex structure with many component parts difficult to mould and assemble; others entrust the seal to small, light sleeves slidable on the surfaces of a holed cylindrical body, the mobility of such sleeves being very precarious and unreliable; still others are of considerable size below the seal gasket of the ring cap for fixing the pump onto the mouth of a liquid container, either axially (see the two said European patents and U.S. Pat. No. 4,277,001 and U.S. Pat. No. 4,775,079) or transversely (U.S. Pat. No. 5,222,636), making them unsuitable for use on small-dimension containers such as required, for example, in the perfumery field.  
         [0003]     The operation of an invertible pump depends on the fact that the liquid enclosed in a container must be able to penetrate into the pump compression chamber by rising along a dip tube (of which one end is mounted on the pump and the other end is free and is positioned in proximity to the container base) when the pump is positioned above the container, but to penetrate directly into said compression chamber from a hole provided in the pump body, and of which the opening is controlled by a unidirectional valve which opens only during pump intake and only when the pump is inverted, i.e. positioned below the container.  
       SUMMARY OF THE INVENTION  
       [0004]     The main object of the present invention is to provide an invertible pump having a structure which is very simple to mould and assemble, and of easy and economical construction, and in particular having a length and width (below and respectively laterally to the pump body) which are equal to or only slightly exceed the dimensions of a similar non-invertible pump. This and other objects are attained by an invertible pump comprising a main body having an upper end and a lower end and defining a chamber within which a piston is sealedly slidable connected to a hollow stem emerging from the upper end of the main body, at the lower end of which there is provided a hole from which there extends a tubular appendix for supporting a dip tube connected to the pump via a unidirectional valve system which is open to enable liquid to arrive in said chamber through the dip tube when the pump is upright, but is closed when the pump is inverted, in the main body there being provided an aperture which is open and free, to enable liquid to arrive directly in the pump chamber when the pump is inverted and in the rest condition, but closes when the pump is operated and its piston moves away from the rest position, wherein said aperture is provided in the upper part of the main body in a position in which it is left free by said piston when the pump is at rest whereas it is closed by said piston when the piston withdraws from its rest position on operating the pump, said unidirectional valve system comprising two balls and a hollow profiled element projecting into said chamber from the lower end of the main body in correspondence with the hole provided at the lower end of the main body, and having two ends both profiled to form seats on which a respective ball can rest and form a seal, one of said balls being disposed within the pump chamber and the other being housed and movable between the hole provided at the lower end of the main body and the cavity of the tubular appendix, said hollow profiled element comprising means for retaining the ball freely oscillable within the pump chamber in proximity to its seat.  
         [0005]     Preferably, said hollow profiled element is formed separately from the pump main body and is inserted into and retained in the pump chamber in correspondence with the hole to which the dip tube is connected. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0006]     The structure and characteristics of the invertible pump of the present invention will be more apparent from the ensuing descriptions of two non-limiting embodiments thereof, given with reference to the accompanying drawings, in which:  
         [0007]      FIGS. 1 and 2  are longitudinal sections through a pump in the upright position, shown respectively at rest and with its piston pressed completely down to dispense an atomized liquid;  
         [0008]      FIGS. 3 and 4  are similar to  FIGS. 1 and 2 , but show the pump inverted in the same utilization state as the preceding figures;  
         [0009]      FIG. 5  is similar to  FIG. 1 , but shows a different embodiment of the invertible pump; and  
         [0010]      FIGS. 6 and 7  are longitudinal sections through just the lower end portion of a variant of the pump of  FIGS. 1 and 2 , shown with the pump in the upright and inverted position respectively. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]     The pump shown in Figures from  1  to  4  comprises a main body  1  housing a sealedly slidable piston  2 , from which there extends a hollow stem  3 , the free end of which is inserted into a suitable seat provided in a dispensing cap  4 : the body  1  can be rigidly fixed by a threaded ring cap  5  onto the mouth of a container (not shown for simplicity) for the liquid to be dispensed.  
         [0012]     The main body  1  is lowerly bounded by a base wall  6 , in the centre of which there is provided a hole connectable to a dip tube  7  which enables the liquid present in the container to rise (when the pump is in the upright position of  FIGS. 1 and 2 ) through the hole in the base wall  6  and to penetrate into the liquid intake and compression chamber bounded within the body  1  by the piston  2  and by a unidirectional seal valve which, in the illustrated example, comprises a small steel ball  9  housed and axially translatable within a housing provided at the upper end of a hollow element  10  in the interior of the chamber or cavity  8 , where a profiled seat is provided on which the ball  9  rests and forms a seal when a liquid present in the chamber  8  is put under pressure by operating the cap  6  and with it the stem  3  and piston  2 . The structure of the pump shown in the upper part of  FIGS. 1 and 2  is of known type and can be structured in various ways: for example that shown in  FIGS. 1-4  is totally similar to that illustrated in EP-A-1334774 (but could be as that illustrated in EP-B-0721803, EP-A-0648545, U.S. Pat. No. 3,627,206 or many others).  
         [0013]     The new and characteristic part of the pump of the invention relates to the lower part of the pump (with reference to the pump in its upright position of  FIGS. 1 and 2 ), where it can be seen that the hollow element  10  at the upper end of which the seal seat for the ball  9  is provided consists of a hollow profiled element at the lower end of which there is provided a further profiled seat on which a ball  11  rests and forms a seal when the pump is used in the inverted position ( FIGS. 3 and 4 ), the ball  11  enabling liquid to freely pass from the dip tube  7  to the chamber  8  when the pump is used in the upright position ( FIGS. 1 and 2 ) because the ball is housed and translatable within a longitudinally grooved cavity within a body appendix  12  on which the tube  7  is mounted.  
         [0014]     The ball  11  is freely oscillable between the hollow element  10  and a projection (not numbered for simplicity) provided in the cavity of the appendix  12 , the ball  9  being oscillable between its seal seat on the element  10  and the (inwardly projecting) ends of cylindrical sectors  13  which extend from the element  10 .  
         [0015]     The element  10  is simply inserted and forced into the cavity  8 , its structure being extremely simple and easy to produce with high precision on an industrial scale, because the overall axial length of the element  10  is very small. It can also be seen that assembly of the described pump is very simple because the ball can be inserted into its housing by simply allowing it to fall into the cavity or chamber  8  before inserting into this cavity the element  10  on which the ball  9  has been previously mounted with considerable ease.  
         [0016]     Finally, in the upper part of the main body  1  there is provided an aperture  14  which freely connects the chamber  8  to the outside of the body  1  when the pump is at rest ( FIGS. 1 and 3 ) but is immediately closed by the pump piston  2  as soon as the piston is withdrawn from its rest position on operating the pump ( FIGS. 2 and 4 ).  
         [0017]     It will now be assumed that the pump is in the upright vertical position ( FIGS. 1 and 2 ), mounted on a container of liquid to be dispensed.  
         [0018]     To prime the pump, the cap  4  is pressed with a finger to lower the piston  2  from the position of  FIG. 1  to that of  FIG. 2  to immediately close the aperture  14 , while the air initially present in the pump chamber is expelled to the outside in traditional known manner, as described in a large number of patents, including those already cited, and in particular in EP-A-1334774.  
         [0019]     Starting from the position of  FIG. 2 , it will now be assumed that the cap is now released so that the pump piston is made to rise by a spring which acts on it: in this manner, a vacuum is formed in the chamber  8  to cause the liquid to rise along the dip tube  7 , bypassing the ball  20  and raising the ball  9 , to penetrate into and fill the chamber  8 .  
         [0020]     At the end of its upward stroke, the piston  2  passes beyond the aperture  14 , but the liquid present in the chamber  8  cannot pass through this aperture, because the pump is used in the upright position. With the pump hence primed and upright, when the pump is operated the aperture  14  firstly closes to pressurize the liquid present in the chamber  8  and force the ball  9  to press and seal against its seat in the hollow element  10 .  
         [0021]     The pump can hence be used in the same manner as a common non-invertible pump of similar structure (in particular that of EP-A-1334774).  
         [0022]     Reference will now be made to  FIGS. 3 and 4  in which the pump is shown in its inverted position, i.e. with the pump body immersed in the liquid contained in the container and with the free end (not shown) of the dip tube  7  open in the air present in the container bottom, now positioned at the top: under these conditions the ball  11  rests and seals against its seat provided on the adjacent end of the hollow element  10  while the ball  9  falls by gravity out of its seal seat ( FIG. 3 ), to be retained by the inwardly projecting ends of the cylindrical sectors  13  of the element  10 .  
         [0023]     The liquid present outside the pump body  1  flows freely through the aperture  14  to fill the pump cavity  8 , when this cavity is under vacuum.  
         [0024]     When the pump is pressed to dispense atomized liquid, the piston  2  immediately closes the aperture  14 , to compress the liquid present in the chamber  8  and hence raise the ball  9  so that it becomes inserted into and seals against its seat in the hollow element  10 : this position is maintained until the piston  2  reaches its end-of-travel position ( FIG. 4 ).  
         [0025]     From that stated and illustrated, it is clear that the length of the invertible pump is very small, equal to or only slightly more than that of a common non-reversible pump, thus facilitating its use in many cases (for example in the pharmaceutical and cosmetics fields), and also facilitating its storage, its handling and its despatch from the manufacturer to the user.  
         [0026]     The hollow element  10  can be easily produced with high precision (given its very small length) and can be inserted, as can the balls, into the pump body  1  also very easily.  
         [0027]      FIG. 5  shows a different (but similar) embodiment of the pump of  FIGS. 1-4 .  
         [0028]     The pumping system applied to the hollow main body  101  will not be described as it is the same as that already described (but could also have a different configuration). Again, in this embodiment the body  101  defines an intake and compression chamber  108  and presents an aperture  114  which is left free by the piston  2  when the pump is in its rest state.  
         [0029]     A hollow element  110  rigidly projects from the base  106  of the body  101  and houses two small sealing balls  109 ,  111  (identical to the already described balls  9  and  11  and having the same function), a dip tube  107  being sealedly mounted on the free end of the appendix  112 .  
         [0030]     It is not necessary to describe the operation of the pump of  FIG. 5 , it being the same as that of the pump shown in  FIGS. 1-4 .  
         [0031]     In the pump shown in  FIGS. 1-4 , the liquid drawn through the dip tube  7  into the appendix  12  through its open free end flows around the ball  9  and then enters the chamber  8  after lifting the ball  9  away from its seal seat in the hollow element  10 . The liquid takes an identical path from the dip tube to the intake chamber in the pump of  FIG. 5 .  
         [0032]     Instead of passing through the open free end of the appendix ( 12  in  FIGS. 1-4 ;  112  in  FIG. 5 ) to which the dip tube ( 7 ;  107 ) is connected, the free end of the appendix could also be closed as represented in  FIGS. 6 and 7 , which show only the end portion of a pump (assumed to be similar to that of  FIGS. 1-4 ), in its upright position in  FIG. 6  and in its inverted position in  FIG. 7 .  
         [0033]      FIGS. 6 and 7  use the same reference numerals as  FIGS. 1-4  to indicate structural parts identical to those of  FIGS. 1-4 , the operation of which will therefore not be repeated.  
         [0034]     With reference now to  FIGS. 6 and 7 , extending from the base wall  6  of the pump there can be seen a tubular appendix (indicated by the reference numeral  112 ) having its free end closed by an end wall  215  to hence define a cylindrical cavity in which the ball  11  is housed and movable. On the outer surface of the appendix  212  there are provided longitudinal grooves  213  (only one of which is shown in section in  FIGS. 6 and 7 ), each opening in correspondence with a respective aperture  214  which connects the cavity of the appendix  212  to a respective groove  213 .  
         [0035]     In  FIG. 6 , the ball is shown in the position it assumes when the pump is held in the upright position: as the dip tube is mounted on the outer surface of the appendix  212 , when the pump is operated to draw liquid from the dip tube  7  the liquid passes through the grooves  213  and penetrates into the cavity of the appendix  212  through the apertures  214 , which are provided in an intermediate position along the length of the appendix in order not to be obstructed by the ball  11  which rests on the end wall  215  ( FIG. 6 ). The pump operation is as already described with reference to  FIGS. 1-4 .  
         [0036]      FIG. 7  is similar to  FIG. 6  but shows the position assumed by the ball  11  when the pump is held in the inverted position.  
         [0037]     As already stated,  FIGS. 6 and 7  relate to the embodiment of  FIGS. 1-4 , however the same structural variant of the tubular appendix can evidently also be applied if the pump is similar to or different from that shown in  FIG. 5 .