Liquid dispensing pump automatically sealable against leakage

A finger-operable pump, adapted to be mounted on a hand-held container of liquid consumer product to provide an unpressurized dispenser package, includes a housing, that defines a pumping chamber, and a plunger telescopically received in the chamber for conventional pumping movement. A stem formed with the plunger projects outwardly of the housing. The pump further incorporates an inprovement in the form of an automatically operable seal arrangement for preventing leakage of liquid which comprises a conical valve seat formed about the mouth of a discharge passage through the plunger and stem and a valve element, having dome-shaped and conical portions, located in the pumping chamber to sealingly engage the valve seat. An actuator button is mounted on the outer end of the plunger stem and is linked, through an elongated connecting rod, to the valve element to move it out of engagement with the valve seat and then to reciprocate the plunger into the pumping chamber away from a home position. A spring automatically closes the valve element and seat when the actuator button is released and then urges the plunger back to its home position. Separate ring and gland seals prevent leakage past the actuator button-plunger stem connection.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a finger-operable pump adapted for 
installation on a non-pressurized, hand-held container of a liquid 
consumer product to form a liquid dispensing package. More particularly, 
this invention relates to an assembly incorporated in the liquid 
dispensing pump for automatically sealing it against leakage. 
Liquid dispensing pumps are now commonly used to dispense various liquid 
products from hand-held, non-pressurized containers. For example, these 
pumps can be used to dispense liquids such as window and all purpose 
cleaners, insecticides, germicides, room deodorizers and the like as well 
as personal products such as hair sprays, deodorants, and colognes. In 
addition, these pumps serve not only as dispensers but also as closures 
for containers during shipment, handling, and storage. 
2. Description of the Prior Art 
Finger-operable liquid dispensing pumps for dispensing liquid consumer 
products are well known. Typically, these pumps include a housing which 
defines a pumping chamber. A piston or plunger is mounted for reciprocal 
pumping movement in the chamber and has a discharge passage therethrough 
which conducts liquid from the chamber. Conventional check valves control 
liquid movement during pumping operation by preventing return flow of 
liquid through the pump. The plunger may also be equipped with an actuator 
button having a atomizing device to break the liquid dispensed through it 
into fine particles to form a mist. 
Since these dispensing pumps also frequently serve as closures for the 
containers on which they are installed, both when used and not used, they 
should provide assured sealing capability to prevent leakage from the 
container. Particularly, they should prevent leakage during shipping and 
related handling as well as during consumer use when the package may be 
inverted or accidentally upset or dropped. 
Various pump designs have been proposed which include leakage preventing 
features. For example, copending U.S. Pat. application Ser. No. 559,894, 
now U.S. Pat. No. 3,949,906 (Peterson et al.), assigned to the assignee of 
the present invention, discloses a sealing assembly having two seal 
members which are shifted between seated and unseated positions by 
rotation of one of relative to the other. Since one seal member is 
non-rotatably coupled to the housing and the other to the plunger, 
relative rotation is effected by rotating the pump plunger relative to the 
pump housing. A camming action is thus produced which either unseats the 
seal members or permits them to reengage. 
Another seal arrangement, disclosed in U.S. Pat. No. 3,239,151 (Boris), 
comprises a housing defining a pump chamber in which a plunger having a 
stem is telescopically received. A tube having a valve member at its lower 
end is slidably mounted in the plunger stem and is coupled at its upper 
end to an actuator button. When the button is depressed, the tube is also 
depressed relative to the plunger to unseat the valve member and provide a 
discharge passage from pump. A sliding seal is made between the tube and 
plunger stem or, in another embodiment, between the tube and the pump 
housing. In different embodiments, the valve element makes either a 
conical or an annular surface seal with an appropriate valve seat. 
Other dispenser pumps similar to that shown in the Boris Patent are 
disclosed in U.S. Pat. Nos. 3,362,344 (Duda); 3,583,605 (Corsette); 
3,627,206 (Boris); 3,640,470 (Susuki et al.); 3,680,790 (Boris); and 
3,724,726 (Susuki et al.). 
SUMMARY OF THE INVENTION 
In the preferred embodiment, to be described below in detail, the liquid 
dispensing pump of the present invention includes a seal arrangement which 
automatically opens when the pump is operated in order to discharge 
liquid, yet which automatically seals after pump operation is completed. 
The seal arrangement also incorporates other features which prevent liquid 
leakage from the pump during periods of storage, shipment, as well as 
during periods of use. 
The pump is finger-operable and is adapted to be mounted on a container to 
dispense the container's liquid contents. It includes a housing, that 
defines a pumping chamber, and a plunger, that has a stem projecting 
outwardly of the housing. The plunger defines a discharge passage and is 
telescopically received in and makes a sliding piston fit with the pumping 
chamber so that it may be reciprocated away from and back to a home 
position. A check valve prevents return flow of liquid back through the 
inlet of the pumping chamber. 
The automatically operable seal arrangement which prevents leakage through 
the pump comprises a conical valve seat formed about the inlet to the 
plunger discharge passage. A cooperating stopper assembly, positioned in 
the pumping chamber, includes a valve element that has a dome or 
ball-shaped portion and a conical portion which respectively make 
secondary and primary seals with the valve seat. The conical valve element 
has a pitch angle different from the pitch angle of the conical valve 
seat. An elongated connecting rod is linked to the valve element, extends 
freely through the plunger discharge opening, and teminates at an end 
projecting outwardly from the plunger. 
The plunger and seal arrangement are operated by an actuator button which 
has a first socket for receiving the projecting end of the connecting rod 
and a second socket, that defines an annular shoulder at the junction with 
the first, for slidingly receiving the projecting end of the plunger stem 
in axially reciprocally movable relation. The button is therefore movable 
toward the housing to a plunger-operating position to disengage the valve 
element and valve seat through the connecting rod. Further movement of the 
actuator button toward the housing then moves the plunger away from its 
home position in pumping action. When the actuator button is released, a 
spring urges the valve element back into engagement with the seat and then 
urges the plunger back to its home position. 
The seal arrangement further includes a ring seal formed on the shoulder in 
the actuator button to abut the projecting end of the plunger when the 
button is moved to the plunger-operating position. Additionally, a gland 
seal is mounted in the button to slidingly seal between the outer surface 
of the plunger and the actuator button. 
The configuration of the stopper assembly valve member and cooperating 
valve seat provides a circular ring of contact between them which 
positively results when the two are engaged. Thus, problems in prior art 
pumps which ordinarily arise, for example, because of the difficulty in 
molding smooth seal mating surfaces without mold parting lines, are 
minimized. The ring and gland seals which seal between the actuator button 
and the plunger also cooperate to prevent leakage therefrom during either 
pump use or non-use. These sealing features are achieved in a pump having 
relatively few parts which are easily manufactured at low cost. 
Thus, it is an object of the present invention to provide a liquid 
dispensing pump which is automatically sealable against leakage during 
operation as well as during shipment, storage, and handling. 
Other objects, aspects, and advantages of the present invention will be 
pointed out in, or will be understood from, the following detailed 
description provided below in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 illustrates the preferred embodiment of the pump of the present 
invention, generally indicated at 10, installed on a container 12 formed 
with a threaded neck 14. The pump is received in a mouth 16 defined by the 
neck 14 to form a closure for the container as well as a means for 
dispensing liquid which is contained in it. 
As shown in detail in FIG. 2, pump 10 includes a cylindrical housing 18, 
the inner surface of which defines a pumping chamber 20. At its bottom 
end, housing 18 is formed with a tail piece 22 which defines an inlet 
passage 24 that communicates with the pumping chamber 20. A dip tube 25 is 
tightly received in the tail piece and extends downwardly to the bottom of 
the container to conduct liquid to the chamber. 
The inlet 24 is formed with a conical valve seat 26 adapted to be engaged 
by a conventional ball check valve 28 to prevent return flow of liquid 
from chamber 20. 
At its upper end, pump housing 18 is formed with a radially outwardly 
directed flange 30 that may rest on a rubber gasket 32 that in turn 
engages the top of container mouth 16. Extending axially upwardly from the 
flange 30 is an annular collar 34 which engages a retainer member in a 
manner to be described below in detail. 
A threaded overcap 36 having a central opening 38 which receives the 
annular collar 34, is internally threaded to match the threaded neck 14 
and thus holds the pump on the container. Accordingly, the gasket 32 is 
tightly clamped between the flange 30 and the top of the container mouth 
to form a tight seal. The container and overcap may, of course, be 
configured in any other suitable manner to attach the two together. 
The pump of the present invention also includes a plunger assembly, 
generally indicated at 40, which comprises a piston 42 having upwardly and 
downwardly directed annular skirts 44 and 46 respectively. These skirts 
make a sliding piston fit with the inner wall of the housing 18 in the 
pumping chamber 20 for conventional pumping movement. The plunger assembly 
also includes an upwardly projecting hollow stem 48 that has an upwardly, 
inwardly tapered outer surface 50 which acts as a vent valve in a manner 
to be described below in greater detail. The stem 48 further defines a 
fluid discharge passage 52 which runs axially through it, and communicates 
through the bottom of piston 42 with the pumping chamber 20. 
The plunger is held in the housing for reciprocal pumping movement by a 
retainer 54 having an axially depending cylindrical boss 56 which is 
received in and encloses the open upper end of the housing 18. The outer 
surface of the boss and the inner surface of the housing collar 34 are 
shaped to form an interlocking snap fit to secure the retainer in the 
housing and thus prevent the plunger assembly from being disengaged 
therefrom. 
The retainer is formed with a central aperture 57 through which the plunger 
stem 48 projects for free reciprocal movement. As can be seen in FIG. 2, 
the tapered outer surface forms a tight seal at the bottom of the retainer 
aperture when the plunger is reciprocated to its uppermost or "home" 
position. However, when the plunger assembly is reciprocated away from 
this home position, the smaller diameter upper portion of the stem forms a 
gap and thus an air passage between it and the aperture. The housing is 
formed with several vent conduits 60, which in cooperation with the gap 
provides a vent passage from atmosphere to the interior of the container 
during pump operation. 
The basic pump described in detail above, incorporates a seal assembly of 
the invention which automatically closes when the pump is not in use, yet 
which automatically opens when the pump is operated to dispense liquid. 
This seal arrangement comprises a conical valve seat 61, shown in detail 
in FIG. 3, formed about the inlet end of discharge passage 52 on the 
bottom face of piston 42. A stopper assembly which cooperates with this 
valve seat is mounted in the pumping chamber and comprises a central valve 
element 62 having a first dome-shaped portion 64 and a second conical 
portion 66 extending upwardly from the dome-shaped portion. The conical 
valve element portion has a different pitch angle than does the conical 
valve seat as can be seen in FIG. 3. Accordingly, their contact when 
engaged is a circular line. Simultaneously, the domed portion makes a 
similar circular line contact with the valve seat at a lower point. The 
interengagement of the conical valve member portion and conical seat forms 
the primary seal at the inlet to the discharge passage while the valve 
seat-domed portion engagement forms a secondary seal. Though it is 
preferred to incorporate both seals in the sealing arrangement, either the 
dome-shaped or the conical valve element portion would be used 
independently of the other if desired. 
The stopper member is also formed with an enlarged diameter disc 83 at the 
base of the dome-shaped portion of valve element 62, and a cylindrical 
guide stem 85 depends from the disc. A stopper base 87 having a socket 89 
is fixed at the bottom of pumping chamber 20 with housing 18. The stem 85 
is received in the socket 89 for free rotational and telescoping axial 
movement to further guide the valve element into firm sealing engagement 
with the valve seat. 
A coil spring 91 is compressed between the bottom of disc 83 and an annular 
shoulder 98 formed on the exterior of the base 87 to urge the stopper 
member upwardly. 
The valve member is operated to disengage from the valve seat by an 
elongated connecting rod 68 which cooperates with an actuator button 70. 
The connecting rod 68 is formed with valve member 62 and projects loosely 
through the discharge passage 52 to extend above the upper end of the 
stem. The rod and discharge passage are dimensioned to permit free fluid 
passage therebetween. 
The actuator botton is formed with a first cylindrical socket 72 which 
receives the projecting end of the elongated connecting rod 68. 
Accordingly, when the button is reciprocated up and down so too is the 
elongated rod. A second socket 74 is also formed so the actuator button 
and is coaxial with and has a larger diameter than the first socket. A 
shoulder 78 is formed at the junction of the respective sockets. 
The second socket 74 receives the projecting end of the plunger stem 48 in 
relatively reciprocally movable relation with a sliding fit. Accordingly, 
when the actuator button is depressed to a plunger-operating position 
relative to the plunger stem, the base of the second socket or shoulder 78 
abuts the upper end 76 of the plunger stem. Further, such movement causes 
the connecting rod 68 to move the valve element 62 out of sealing 
engagement with the valve seat 61. Therefore, the valve element-valve seat 
engagement is automatically broken when the actuator button is depressed. 
Further depression of the actuator button drives the plunger downwardly in 
pumping action in the pumping chamber to force liquid around the 
connecting rod out of the discharge passage into the actuator button (FIG. 
4). As shown in detail in FIGS. 2 and 4, the actuator button has an 
internal discharge passage 80 which communicates with an atomizing nozzle 
82 to provide an outlet orifice from which the liquid is ejected. 
When the actuator button 70 is released, spring 91 urges the stopper member 
upwardly to sealingly engage the valve element and valve seat. Thereafter, 
the entire plunger assembly is urged back to its home position to draw 
liquid into the pump chamber with pumping movement. 
The seal arrangement of the present invention also includes features for 
sealing the actuator button, which is reciprocally movable as described 
above, on the plunger stem and for insuring that the frictional forces are 
such that the valve element and seat disengage before plunger movement is 
effected. Specifically, the shoulder 78 formed internally of actuator 
button 70 is provided with a ring seal 84 having a generally V-shaped 
cross-section. A ring seal accepting recess or seat 86 is formed in the 
upper end 76 of the plunger stem 48. Thus, as shown in FIG. 4, when the 
actuator button is moved to the plunger-operating position, the ring seal 
and recess interengage to prevent liquid flow from passing therebetween to 
thus insure that all liquid is properly ejected through the atomizing 
nozzle 82. Of course, other seal configurations may be used in place of 
V-shaped ring seal 84 and recess 86. 
In addition, the actuator button is provided with a resilient gland seal 88 
having an upwardly, inwardly directed conical portion 90 which slides 
against the outer surface 50 of the plunger stem 48. This gland seal 
prevents leakage of liquid which might pass over the top of the plunger 
stem and between the second socket 74 and the stem 48 during periods when 
the pump is not used. 
The influence of frictional forces between the ring seal and recess on the 
sliding connection between the button and plunger stem is negligible. 
Moreover, the gland seal facilitates easy sliding movement between the 
button and the plunger stem while serving as an effective seal. Therefore, 
the balance of frictional forces between the button and stem and between 
the plunger piston and pump housing is such that the valve element and 
seat disengage prior to movement of the plunger when the button is 
depressed. Similarly, the valve element and seat reengage prior to 
movement of the plunger when the button is released after depression. 
Although a specific embodiment of the present invention has been described 
above in detail, it is to be understood that this is for purposes of 
illustration. Modifications may be made to the described structure by 
those skilled in the art in order to adapt this automatically sealing pump 
to particular applications.