Abstract:
Manually operable invertible pump for dispensing atomized liquids, the pump having a very compact structure and a flexible diaphragm valve for controlling liquid entry into the pump when this is in an inverted or partly inverted position.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a manually operable invertible pump for dispensing atomized liquids withdrawn from a liquid container, on the mouth of which the pump is mounted usable both in the upright position, i.e. with the pump facing upwards from the container,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 
   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 those required, for example, in the perfumery field. 
   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 upright 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 
   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 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 defining a chamber for the intake and compression of determined quantities of the liquid to be dispensed, a dip tube connected to said chamber via a hole provided in the base wall of the main body and via a first unidirectional valve system which enables the liquid to arrive in said chamber through the dip tube when the pump is upright but prevents liquid arrival when the pump is inverted, there being provided in the main body an aperture provided with a second unidirectional valve system which enables the liquid to directly arrive in the compression chamber when the pump is inverted but prevents this arrival when the pump is upright, wherein said second valve system comprises a cup-shaped body sealedly mounted on the outer peripheral surface of the main body to define with the adjacent extremity on the said main body an annular chamber housing and retaining a flexible element which when the pump is at rest or being used in the upright position is elastically urged to seal against a profiled edge provided on the base wall of the cup-shaped body, said annular chamber being in direct communication with said intake and compression chamber via an aperture provided in the main body, in the base of the cup-shaped body there being provided a first hole to which said dip tube is connected and a second hole which is open and in direct communication with said chamber aperture when the pump is inverted and is operated to draw liquid into the chamber of the main body, the flexible element having a central hole which enables said chamber to sealedly communicate with the dip tube through the first valve system. 
   Preferably, a tubular element is provided projecting from one and the other side of said central hole of the flexible element, the two free ends of said tubular element being sealedly fixed rigidly to the dip tube and, respectively, to that hole of the main body to which the tube is connected. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     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: 
       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; 
       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; 
       FIG. 5  is similar to  FIG. 1 , but shows a different embodiment of the invertible pump; and 
       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 in the upright and inverted position respectively. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   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. 
   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, consists of a small plastic ball  9  housed and axially translatable within a housing  10  projecting from the base wall  6 , 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 pump as described up to this point 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-B-0721803 (but could be as that illustrated in EP-A-1334774, EP-A-0648545, U.S. Pat. No. 3,627,206 or many others). 
   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 on the outer surface of the main body  1  there is sealedly mounted a cup-shaped body  11  having a base wall  12  which defines an annular chamber  13  with the adjacent end of the body  1 , the chamber  13  being in free communication with the chamber  8  via an aperture  14  provided in the main body  1  and left free by the cup-shaped body. 
   Between the base wall  12  of the cup-shaped body  11  and the adjacent end of the main body  1  there is housed a flexible discoidal element  15  having a central hole, from one and the other side of which there project two small tubular elements  16 ,  17 , one of which is sealedly inserted and securely retained in a suitable seat (for simplicity not numbered, but clearly visible in the drawings) provided in the base wall  12  of the body  1  where a hole (also not numbered) is provided at the centre of the housing  10 , on the profiled seat of which the ball  9  can form a seal; whereas the other tubular element  17  is inserted into and sealedly retained in the cavity of a hole provided at the centre of the base wall  12 , from this hole there extending a hollow appendix  18 , on the end of which the dip tube  7  is mounted. 
   From  FIGS. 1–4  it can be seen that from the base wall  12  of the body  11  there projects (towards the body  1 ) a profiled rim consisting of an annular step against which the discoidal element  15  is elastically urged to form a seal: the elastic pressure of the peripheral edge of the discoidal element  15  on said profiled rim is ensured by the fact the element  15  is rigid with the two tubular elements  16 ,  17  which are rigidly fixed in the seats into which they are inserted. 
   From the figures it can also be seen that in the base wall  12  of the cup-shaped body there is provided a hole  19  and that the hollow appendix  18  houses an axially translatable small ball  20 , which cannot escape from the cavity in the appendix because inside this appendix there is provided a ledge or the like on which the ball can rest (with the pump upright) without however closing the hole of the appendix, in which one or more longitudinal grooves are provided (not numbered for simplicity but clearly visible in the drawings), to leave the passage free for the liquid which rises from the dip tube to the pump. 
   Finally it can be seen that on the free end of the tubular element  17  there is provided a profiled seat on which the ball  20  can rest and form a seal when the pump is used in the inverted position ( FIGS. 3 and 4 ). 
   Before describing the operation of the invertible pump it is important to note the great simplicity of its structure and its ease of assembly. In this respect, the ball  20  can be inserted into the appendix  18  by simply allowing it to fall freely into the cup-shaped body  11  before this is mounted in the pump; the tubular element  16  can be easily inserted into its seat in the pump, either before mounting the cup-shaped body on the pump, or by firstly inserting and locking the tubular element  17  in its seat in the hollow appendix  18  and then mounting the cup-shaped body on the pump, so automatically inserting the tubular element  16  in its seat. 
   It should be noted that the transverse and longitudinal dimensions of the invertible pump are only slightly greater than those of a common non-invertible pump of similar structure. 
   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. 
   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 , 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. 
   Starting from the position of  FIG. 2 , it will 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 . 
   With the pump hence primed and upright, the pump is again operated to pressurize the liquid present in the chamber  8  and force the ball  9  to press and seal against its seat: the liquid which fills the annular chamber  13  and is in communication with the chamber  8  via the aperture  14  cannot escape to the outside of the pump body because the flexible discoidal element  15  is urged by the pressurized liquid to seal against the annular projection provided on the base of the cup-shaped body. 
   The pump can hence be used in the same manner as a common non-invertible pump of similar structure. 
   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  free and open in the air present in the container bottom, now positioned at the top: under these conditions the ball  20  rests and seals against its seat provided on the end of the tubular element  17 . Starting from the position of  FIG. 3  and with the pump already primed, when pressure is released from the cap  4  the piston begins to descend along the intake chamber and the discoidal element  15  passes from its sealing position of  FIG. 3  (in which it is elastically urged against the profiled rim projecting from the base wall  12 , so preventing communication between the hole  19  and the aperture  14 ) to that of  FIG. 4  in which the discoidal element  15  is curved and raised from the said profiled rim by the effect of the vacuum created in the intake chamber  8 . In this manner the liquid can pass freely through the hole  19  and aperture  14  to fill the chamber  8 : when piston translation within the main pump body ceases, the discoidal element  15  returns elastically and automatically to its rest position in which it sealedly closes the hole  19 . It should again be noted that during this intake stage, the air present in the container cannot enter the chamber  8  because the ball  20  seals against the seat on the tubular element  17  or at least creates a strong resistance to air passage. 
   When the pump is pressed to dispense atomized liquid, the pressurized liquid present in the chamber  8  urges the discoidal element  15  against the profiled rim of the cup-shaped body (hence increasing the seal effect) and lifts the ball  9 , which becomes inserted into and seals against its seat in the housing  10 , this position being maintained until the piston  2  reaches its end-of-travel position ( FIG. 3 ). 
   Finally it can be seen that even during initial priming of the pump in its inverted position, the ball  20  seals against the end of the tubular element  17 , while the discoidal element passes from its sealing position (with the piston pressed totally down as in  FIG. 3 ) to the raised position of  FIG. 4 , so enabling liquid to enter the intake chamber  8  through the hole  19  and the aperture  14 . 
   From that stated and illustrated, it is clear that the length of the invertible pump is very small, 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.  FIG. 5  shows a different (but similar) embodiment of the pump of  FIGS. 1–4 . 
   The pumping system applied to the hollow main body  101  will not be described as it is the same as that illustrated in EP-A-1334774 (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 a cup-shaped body  111  sealedly mounted on the lower end of the body  101 . 
   An elongate hollow appendix  150  projects from the base  106  of the body  101  and houses two small sealing balls  109 ,  120  (identical to the already described balls  9  and  20  and having the same function): a dip tube  107  is sealedly mounted on the free end of the appendix  150 , there also being mounted on said aperture (but positioned within the cup-shaped body  111 ) a flexible discoidal element with a central hole (to enable it to be mounted on the appendix  150 ), its free ends when in the rest condition being elastically urged to form a seal against a profiled rim projecting from the base of the cup-shaped body, so preventing communication between one or more holes  119  provided in the base of the cup-shaped body and the chamber  113 , which is in direct communication with the aperture  114 . 
   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 . 
   In the pump shown in Figures from  1  to  4 , the liquid drawn through the dip tube  7  passes through the open free end of the hollow appendix  18 , flows around the ball  20  and then rises above the ball  20  to enter the intake chamber  8 . The liquid takes an identical path from the dip tube to the intake chamber in the pump of  FIG. 5 . 
   In both cases however, the free end of the pump hollow appendix on which the dip tube is sealedly mounted could also be closed, while achieving the same result. 
   For example, with reference to  FIGS. 6 and 7  which show only the end portion of the pump of  FIGS. 1–4 , it can be seen that the end portion of the tubular element  17  (the same reference numeral is used as already used in  FIGS. 1–4  to clarify the understanding of this variant without illustrating the structure and operation of the entire pump, which is exactly as already described in relation to these figures) is inserted into a hollow cavity (projecting from a cup-shaped body, not shown for simplicity) indicated by the reference numeral  218  and is closed by an end wall  221 , hence defining a cylindrical cavity in which the ball  20  is movably housed. Grooves  219  (only one of which is shown in longitudinal section in  FIGS. 6 and 7 ) are provided in the outer surface of the hollow appendix  218 , each opening in correspondence with a respective aperture  220  which connects the internal cavity of the appendix  218  to each groove  219 . 
   In  FIG. 6 , the ball is shown in the position it assumes when the pump is operated in the upright position: it can be seen that the liquid is drawn into the pump through the dip tube  7 , passes through the groove  219  and penetrates into the hollow appendix  218  through the apertures provided in an intermediate position along the length of the hollow appendix so as not to be obstructed by the ball  20 . 
     FIG. 7  is similar to  FIG. 6  but shows the position assumed by the ball  20  when the pump is used in the inverted position. 
     FIGS. 6 and 7  relate to the embodiment of  FIGS. 1–4 , however the same structural variant (i.e. the presence of the grooves on the outside of the hollow appendix on which the dip tube is mounted, and the presence of apertures which pass through the thickness of the hollow appendix in correspondence with said grooves) can evidently also be applied if the pump is that shown in  FIG. 5 .