Patent Publication Number: US-6209761-B1

Title: Pump with air intake

Description:
The present invention relates to a pump for mounting on a receptacle to extract a quantity of substance therefrom and to dispense it, and more particularly it relates to a pump of the type that has air intake, i.e. that enables air to penetrate into the receptacle to compensate for the quantity of substance extracted by the pump. 
    
    
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 3,759,426 discloses a pump for mounting on a receptacle, the pump comprising a pushbutton that is movable relative to a pump body between a high position and a low position and that co-operates therewith to define a pump chamber of variable volume, the pump body having a vent suitable for communicating via a passage with the outside of the receptacle when the pushbutton is in an intermediate position between its high and low positions, thereby enabling air to enter into the receptacle while substance is being sucked into the pump chamber. 
     The pushbutton has an outer skirt suitable for isolating the vent when the pushbutton is in its high position and when it is in its low position. The pushbutton has an inner skirt which co-operates with the outer skirt to define a groove suitable for housing a return spring. 
     The outer skirt is exposed to the possibility of being dirtied, which dirt can then come into contact with the substance contained in the pump body. 
     In addition, the return spring is immersed in the substance, which can give rise to problems of compatibility. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     An object of the invention is to provide a novel pump with air intake which is not only low cost in structure and reliable in operation, but which also guarantees good conditions for conserving the substance in the receptacle. 
     The pump of the invention is of the type comprising a pump for mounting on a receptacle, the pump comprising a pushbutton that is movable relative to a pump body between a high position and a low position, and that co-operates with the pump body to define a pump chamber of variable volume, the pump body having a vent suitable for communicating via a passage with the outside of the receptacle when the pushbutton is in an intermediate position between its high and low positions, thereby enabling air to enter into the receptacle while substance is being sucked into the pump chamber, and wherein the pushbutton includes an inner skirt integrally formed therewith and suitable for sliding in sealed manner inside the pump body, said inner skirt being shaped so as to isolate said vent from the outside both when the pushbutton is in its high position and when it is in its low position. 
     Thus, in the invention, the inside of the receptacle communicates with the outside only when the pushbutton is in an intermediate position between its high and low positions, i.e. at the moment of use. 
     The substance contained in the receptacle therefore remains isolated from the outside when the pushbutton is in its low position for transport or when it is in its high position waiting for use. 
     By way of example, this prevents the solvents or perfumes contained in the substance inside the receptacle escaping from the receptacle through the air intake passage in the event of the pump not being used for a long period of time. 
     The inner skirt of the pushbutton, because of its position inside the pushbutton, is not subject to possible dirtying that might hinder the operation of the pump or contaminate the substance contained inside the receptacle. 
     In a particular embodiment, the inner skirt presses in sealed manner against the pump body via its bottom portion, and the distance between the vent and said bottom portion when the pushbutton is in its low position is less than or equal to, and preferably substantially equal to, the displacement stroke of the pushbutton from its low position towards its high position, such that said bottom portion isolates said vent from the outside when the pushbutton is in its high position. 
     Advantageously, the inner skirt presses in sealed manner via its top portion against the top end of the pump body when the pushbutton is in its low position. 
     Preferably, the inner skirt has a setback between its bottom portion and its top portion, the setback providing an annular space inside the pump body, with said vent opening out into said space while the pushbutton is in its low position and while the pushbutton is in an intermediate position between its high position and its low position. 
     In a particular embodiment, the pump body is connected at its top end via an annular bearing surface to a mounting skirt secured to a neck of the receptacle. 
     Advantageously, the mounting skirt is extended upwards by a cylindrical wall that defines a guide for a helical spring that operates in compression to return the pushbutton to its high position. 
     The pushbutton preferably has a delivery valve including a ball constituting its valve member. 
     The ball is held in a housing of the pushbutton by retaining means which are advantageously formed integrally therewith by molding a plastics material. 
     Preferably, the above-mentioned housing is situated in a duct, and said retaining means are constituted by the bottom end of the duct, which end is shaped so as to enable the ball to be put into place by elastic deformation. 
     Advantageously, the pump body has a suction valve including a ball as its valve member, and the bottom end of the above-mentioned duct is organized in such a manner as to hold the suction valve ball in the closed position when the pushbutton is in its low position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics and advantages of the present invention will appear on reading the following detailed description of a non-limiting embodiment, and on examining the accompanying drawings, in which: 
     FIG. 1 is a diagrammatic axial section view of a pump constituting an embodiment of the invention; 
     FIG. 2 shows, in isolation, the pushbutton of the pump shown in FIG. 1; 
     FIG. 3, shows, on its own, the fixed portion of the pump shown in FIG. 1; 
     FIG. 4 shows a detail of the pushbutton; and 
     FIGS. 5 and 6 show the pushbutton in an intermediate position and in its high position, respectively. 
    
    
     MORE DETAILED DESCRIPTION 
     The pump  1  shown in FIG. 1 has a moving pushbutton  2  capable of moving vertically along an axis X relative to a fixed portion  3 , which fixed portion has a mounting skirt  4  secured to the neck  5  of a conventional receptacle  6  that is shown in part only. 
     In the embodiment described, the mounting skirt  4  is screwed onto the neck  5 , but in a variant it could be fixed thereto in some other manner, e.g. by snap-fastening. 
     The mounting skirt  4  is extended upwards by a cylindrical wall defining a guide  7  both for the pushbutton  2  and for a helical spring  8  about the axis X and operating in compression. 
     At its top end, the guide  7  has an annular rim  47  which limits the upward displacement stroke of the pushbutton  2 . 
     At its bottom end, the spring  8  rests against an annular bearing surface  9  on the fixed portion  3 . 
     This bearing surface  9  extends radially inwards from the region where the mounting skirt  4  and the guide  7  meet. 
     The top end of the spring  8  bears against the end wall  10  of an annular groove  11  in the pushbutton  2 . 
     The spring  8  is not exposed to the substance, unlike the spring used in the pump described in above-mentioned U.S. Pat. No. 3,759,426. There is therefore no problem of compatibility between the material used for making the spring and the substance contained in the receptacle. 
     This groove  11  is formed between an inner skirt  12  that is circularly symmetrical about the axis X, and an outer skirt  13  that is coaxial therewith. 
     Locking means are provided on the facing faces of the outer skirt  13  and of the mounting skirt  4  to enable the pushbutton  2  to be locked in its low position as shown in FIG.  1 . 
     This locking is used while the receptacle  6  is being transported, e.g. to ensure that there is no accidental leakage of the substance. 
     In the embodiment described, the above-mentioned locking means comprise studs  14  formed on the radially outer surface of the mounting skirt  4  and portions in relief  15  situated on the radially inner surface of the outer skirt  13 . 
     These studs  14  and portions in relief  15  can cooperate in the manner of a bayonet type fastening. 
     To lock the pushbutton  2  in its low position, the user presses it down while the portions in relief  15  are angularly offset from the studs  14  so as to bring said portions down to the level of the studs, and then causes the pushbutton  2  to pivot about the axis X so as to engage the portions  15  in relief beneath the studs  14 . 
     When the user releases the pushbutton  2 , the studs  14  prevent the pushbutton from rising under drive from the spring  8 . 
     To unlock the pushbutton  2 , the user presses it down slightly and then pivots it so as to release the portions in relief  15 . 
     When the pushbutton  2  is in its high position, the outer skirt  13  bears via portions in relief  48  formed above the above-mentioned portions in relief  15 , against the annular rim  47  of the guide  7 , as can be seen in FIG.  6 . 
     A central duct  16  is integrally formed with the inner skirt  12  by molding a plastics material. 
     The duct  16  is centered on the axis X and its top end is connected to a lateral duct  17 , likewise integrally formed with the remainder of the pushbutton  2  by molding a plastics material. 
     The lateral duct  17  opens to the outside of the pushbutton  2  via an outlet orifice  40  which points in a direction Y that is perpendicular to the axis X. 
     The above-mentioned annular bearing surface  9  is connected to the top end of a tubular pump body  18  which is closed at its bottom end by an end wall  19 . 
     The end wall  19  constitutes a seat for a ball  20  and it has an endpiece  42  for connection to a dip tube  21  that extends to the bottom of the receptacle  6  where the tube opens out. 
     The ball  20  together with its seat formed on the end wall  19  constitutes a suction valve as described below. 
     As can be seen in FIG. 4, the bottom end of the central duct  16  defines a housing  35  in which a ball  22  is retained. 
     The ball  22  together with its seat made inside the housing  35  constitutes a delivery valve, as described below. 
     The bottom portion  23  of the inner skirt  12  is shaped to slide in sealed manner in contact with a circularly cylindrical portion of the inside surface of the pump body  18 . 
     The top portion  24  of the inner skirt  12  is shaped to press in sealed manner against the top end of the pump body  18  when the pushbutton  2  is in its low position, as shown in FIG.  1 . 
     More precisely, the top portion  24  is shaped to be inserted at a friction fit in the pump body  18  when the pushbutton  2  is in its low position. 
     The inner skirt  12  has a setback  46  between its bottom portion  23  and its top portion  24 . 
     This setback  46  co-operates with the pump body  18  to define an annular space  25  whose function is explained below. 
     A vent  26  opening out at the base of the neck  5  is made in the pump body  18  to put the above-mentioned annular space  25  into communication with the inside of the receptacle. 
     The pump body  18  presses in sealed manner at its top end against the inside surface of the neck  5 . 
     The bottom end of the central duct  16  housing the ball  22  is described in greater detail below with reference to FIG.  4 . 
     The duct  16  has an inside shoulder at  30 , and on going past said shoulder in a downward direction inside the housing  35 , the diameter of the duct passes from a value d 1  that is smaller than the diameter of the ball  22  to a diameter d 2  which is slightly greater than the diameter of the ball. 
     The inside diameter of the duct  16  then tapers progressively downwards over a conical surface  31  until it reaches a value d 3  that is slightly smaller than the diameter of the ball  22 . 
     The conical surface  31  serves as a seat for the ball  22  and the cylindrical surface of diameter d 2  extends above said surface  31  around the axis X to a height which is sufficient to enable the ball  22  to move away from its seat while substance is being dispensed in such a manner as to enable the desired flow rate to be obtained. 
     At its bottom end, the central duct  16  terminates in tabs  32  which are directed radially inwards and shaped in such a manner as to be capable of deforming radially outwards while the ball  22  is being inserted from the bottom into the housing  35  along arrow F. 
     Recesses  33  are formed in the outsides of the tabs  32  where the join the remainder of the duct  16  so as to impart the flexibility required for enabling the ball  22  to be installed. 
     Portions in relief  36  are formed at the top portion of the housing  35  to prevent the ball  22  from closing the central duct  16  while the substance is being dispensed. 
     FIG. 3 shows the fixed portion  3  of the pump in isolation. 
     As can be seen in FIG. 3, the end wall  19  has a conical recess  37  centered on the axis X and converging downwards, for the purpose of serving as a seat for the ball  20 . 
     Tabs  38  extend said recess  37  upwards so as to constitute a cage  45  in which the ball  20  is retained, while leaving it free to lift off the seat  37  while substance is being taken from the receptacle. 
     In the example described, there are four such tabs  38  and each has a tooth  39  projecting radially inwards. 
     The teeth  39  are chamfered so as to facilitate inserting the ball  20  downwards into the cage  45 . 
     The tabs  38  deform radially outwards in elastic manner so as to enable the ball  20  to move past the teeth  39  while the ball is being put into place in the cage  45 . 
     The end of the recess  37  communicates via a hole  41  with the inside of the endpiece  42  in which the dip tube  21  is engaged as a force-fit, as shown in FIG.  1 . 
     It will be observed that when the pushbutton  2  is in its low position as shown in FIG. 1, the tabs  32  of the central duct  16  come into contact with the ball  20  and are subjected to a small amount of elastic deformation, thereby holding the ball  20  against its seat  37 . 
     The endpiece  42  is thus closed and substance is prevented from rising into the pump, thereby reducing the risk of any accidental leakage of substance while the receptacle is being transported. 
     The annular space defined by the pump body  18  and the inner skirt  12  around the central duct  16  constitutes a pump chamber  43  whose volume varies as the pushbutton  2  moves axially along the axis X. 
     The pump  1  operates as follows. 
     Once the pushbutton  2  has been unlocked as explained above, it rises under the return force of the spring  8  until it takes up the high position as shown in FIG. 6, after passing through the intermediate position as shown in FIG.  5 . 
     During the upward movement of the pushbutton  2 , the volume of the pump chamber  43  increases, thereby establishing suction therein, lifting the ball  20  of the suction valve, and sucking substance from the bottom of the receptacle  6  along the dip tube  21 . 
     The ball  22  of the delivery valve is then pressed against its seat  31  and isolates the central duct  16 . 
     The taking of substance from the receptacle  6  causes the pressure therein to drop. 
     In the embodiment described, air is allowed to enter into the receptacle  6  during the upward movement of the pushbutton  2  because the vent  26  is in communication with the outside of the receptacle via the annular space  25 . 
     In FIG. 5, arrow A shows the path followed by the air entering the receptacle  6  while the pushbutton  2  rises. 
     The air passes initially between the mounting skirt  4  and the outer skirt  13  of the pushbutton  2 , and then reaches the vent  26  by passing along the annular space  25 . 
     It will be observed that ingress of air into the receptacle  6  is made possible by the fact that the top portion  24  of the inner skirt  12  has ceased to press in sealed manner against the pump body  18 . 
     When the pushbutton  2  reaches its high position as shown in FIG. 6, the bottom portion  23  of the inner skirt  12  takes up a position in register with the vent  26  so as to close it. 
     To this end, the up stroke of the pushbutton is substantially equal to the distance    1   between the vent  26  and the bottom portion  23  of the inner skirt  12  when the pushbutton is in its low position. 
     As a result, the inside of the receptacle  6  again ceases to communicate with the outside so as to ensure that the substance contained in the receptacle  6  is properly conserved. 
     In other words, the pushbutton  2  can be left in its high position without any fear of the substance being degraded by outside air because the passage via which the vent  26  communicates with the outside is closed by the bottom portion  23  of the inner skirt  12 . 
     When the user pushes down the pushbutton  2 , the volume of the pump chamber  23  decreases, thereby compressing the substance that is to be found therein. 
     The ball  20  of the suction valve is then pressed against its seat  37 , preventing any return of the substance into the receptacle  6 , while the ball  22  of the delivery valve is lifted by the pressure of the substance, thereby enabling it to flow via the central duct  16  and then via the lateral duct  17  so as to reach the dispensing orifice  40 . 
     By means of the invention, a pump is provided that has few component elements, and specifically in the example described: a pushbutton  2  and a fixed portion  3  each constituted (with the exception of the two balls and the spring) as a single molded piece respectively of polyethylene and of polypropylene in particular, which are of low cost to manufacture and reliable in operation. 
     The risk of the substance leaking while the receptacle is being transported is reduced by the ball of the suction valve being locked in place. 
     Finally, the pump enables the substance to be conserved while being protected from outside air even when the pushbutton is left for a long period of time in its high position. 
     Naturally, the invention is not limited by the embodiment described above. 
     In particular, various modifications can be made to the pump, for example concerning the manner in which the fixed portion  3  is fixed to the receptacle  6 .