Pump device for fluid dispenser

Abstract

A pump device for fluid dispensers is provided whose chamber is partitioned into a pressure room and a fluid room. A piston element is engaged inside the pressure room by an actuating rod to push the piston element downward, or by a resilient element beneath the piston element to restore the piston element back to the top. An air valve element at the bottom of the piston element automatically opens or closes the induction of air to the pressure room when the piston element is moved upward or downward. The fluid room is dedicated to the passage of the fluid. A normally closed fluid valve element is provided at the bottom of the fluid room. When the fluid in the container device is pressurized, the fluid pushes open the fluid valve element, flows into the fluid room and then out of the spout of the pump device.

Description

BACKGROUND OF THE INVENTION

(a) Technical Field of the Invention

The present invention generally relates the pump device for fluid dispensers, and more particular to a pump device having partitioned rooms for air and fluid separately.

(b) Description of the Prior Art

Fluid dispensers are commonly found in the household kitchens and bathrooms for holding liquid soaps and detergents, shampoo and conditioners, hand and body lotions, etc. A fluid dispenser usually contains a fluid container device and a pump device mounted on top of the container device. A conventional pump device is shown in FIG. 1.

As illustrated, the conventional pump device mainly contains a spout A1, a hollow actuating rod A2 attached to the bottom of the spout A1, a fastening element A3 for locking the spout A1 when the pump device is not in use, a closure cap A4 for locking the pump device to the container device (not shown), a hollow chamber A5, a plug element A7 attached to the bottom of the actuating rod A2 via an intermediate hollow rod A7 1, a piston element A6 wrapping around the rod A71 positioned on top of the plug element A7 having air-tight contact with the inner wall of the chamber A5, a spring A8, a ball valve A9, and a dip tube A10. The operation ofthe pump device is as follows. When the spoutAl is pushed downward, the plug element A7 compresses the spring A8 and the piston element A6 drives the air in the chamber A5 downward, forcing the ball valve A9 to block the dip tube A10. When the pressure on the spout A1 is released, the plug element A7 and the piston element A6 are automatically restored to their original position by the spring A8. In the mean time, the air in the chamber A5 is expelled through a number of ventilation holes A51 configured on the top wall of the chamber A5, thereby vacuuming the space inside the chamber AS. The fluid stored in the container device is therefore sucked into the dip tube A10, pushes the ball valve A9 aside, and flows into the chamber A5. When the spout A1 is pushed again, the descending of the piston element A6 forces the fluid inside the chamber A5 to flow into a through hole A72 on the rod A71 between the piston element A6 and the plug element A7, through the actuating rod A2, and then out from the spout A1.

Please note that, when the plug element A7 and the piston element A6 are pushed down, the friction between the piston element A6 and the inner wall of the chamber A5 causes a tiny gap developed between the piston element A6 and the plug element A7, thereby exposing the through hole A72. As the ball valve A9 blocks the dip tube A10 under air pressure, only the fluid in the chamber A5 will flow through the through hole A72. On the other hand, when the plug element A7 and the piston element A6 are restored as the spring A8 expands, the friction between the piston element A6 and the inner wall of the chamber A5 causes the plug element A7 and the piston element A6 to tightly attach to each other, thereby closing the through hole A72 and prohibiting the fluid to pass through. In the mean time, the fluid in the container device is sucked into the chamber A5 to make up the amount of fluid dispensed in the previous stroke.

The foregoing conventional pump device has a number of shortcomings. First of all, as the fluid to be dispensed is stored inside the chamber, various components of the pump device are completely immersed in the fluid. These components will quickly deteriorate from the erosion of the fluid, resulting in short operation life. Especially for metallic components such as the spring, they will even engage in chemical reaction with the fluid, thereby altering the quality and property of the fluid.

Secondly, as the fluid has to be pumped into the chamber via narrow dip tube and again through the actuating rod, the viscosity of the fluid significantly affects the operation of the pump device. For highly viscous fluid, a user has to exert additional force to obtain an appropriate amount of the fluid in a longer period of time. In other words, there is a notable hysteresis phenomenon for both the application of force and the response of the pump device.

Thirdly, the same hysteresis problem would also lead to the fluid's continuous dripping from the spout after dispensing as the highly viscous fluid gradually releases its pressure, resulting in user dissatisfaction.

In addition, as the ball valve is the only device blocking the contact of the fluid inside the container device with outside air and the ball valve can freely move inside the chamber, the fluid's continuous exposure to outside air is inevitable and the conventional pump device is therefore not appropriate for highly volatile fluid.

SUMMARY OF THE INVENTION

The primary purpose of the present invention is to provides a novel structure for the pump device of fluid dispensers to obviate the foregoing shortcomings of prior approaches.

The major characteristic of the present invention is that the chamber of the pump device is partitioned into a pressure room and a fluid room. A piston element is engaged inside the pressure room by an actuating rod to push the piston element downward, or by a resilient element beneath the piston element to restore the piston element back to the top. An air valve element at the bottom of the piston element automatically opens or closes the induction of air to the pressure room when the piston element is moved upward or downward. As such, air pressure is reliably applied to the fluid in the container device as the air flows from the chamber into the container device via an outlet hole therebetween.

The fluid room is dedicated to the passage of the fluid. A normally closed fluid valve element is provided at the bottom of the fluid room. When the fluid in the container device is pressurized, the fluid pushes open the fluid valve element, flows into the fluid room and then out of the spout of the pump device.

Compared to the prior arts, the proposed pump device has quite a few advantages. Except when the fluid is discharged, the air valve element and the normally closed fluid valve element seals the container device at all time, avoiding volatile fluid to evaporate. Additionally, the separation of pressure room and the fluid room avoids the erosion and deterioration of the components as often found in prior arts resulted from their direct contact with and immersion within the fluid, thereby lengthening the operation life of the pump device considerably. Further more, according to the present invention, the air pressure is directly applied to the fluid to drive them out of the container device via a shorter passageway, in contrast to the prior approaches which sucks the fluid out through a longer passageway. The present invention is therefore more responsive to the user operation, requires less user effort, and does not have the dripping problem, even for fluid of high viscosity.

The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a conventional pump device.

FIG. 2 is a perspective view showing the appearance of a pump device according to an embodiment of the present invention.

FIG. 3 is a perspective exploded view showing the various components of the pump device of FIG. 2.

FIG. 4 is a sectional view showing the pump device of FIG. 2.

FIG. 5 contains the top and sectional views showing the fluid valve element of the pump device of FIG. 2.

FIG. 6 is a sectional view showing another embodiment of the piston element of the present invention.

FIG. 7 is a sectional view showing the operation scenario of the pump device of FIG. 2.

FIG. 8 is a sectional view showing an application of the pump device of FIG. 2.

FIG. 9 is a sectional view showing another application of the pump device of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

Please refer to FIGS. 2 and 3. As illustrated, a pump device 10 according to an embodiment of the present invention mainly contains a head element 1, an actuating rod 2, a fastening element 3, a piston element 4, a resilient element 5, a body member 6, and a fluid valve element 7. The head element 1 is provided on the top end of the actuating rod 2, and a screw thread 11 is configured around the bottom portion of the head element 1. A corresponding screw thread 31 is configured around the inner wall of the ring-shaped fastening element 3 so that, when the pump device is not in use, the head element 1 can be screwed into the fastening element 3. The other end of the actuating rod 2 is embedded inside a through hole 41 in the center of the piston element 4. The head element 1, the actuating rod 2, and the piston element 4 therefore can be engaged in vertical movement together.

The body member 6 has a hollow chamber 62 configured on top of an enclosure cap 63 with a discharging spout 61 extended from the outer wall of the chamber 62. As shown in FIG. 4, the chamber 62 is partitioned into two separate rooms, a pressure room 621 and a fluid room 622. The actuating rod 2 penetrates into the pressure room 621 via the fastening element 3 which seals the piston element 4 from the top. The resilient element 5 is positioned beneath the piston element 4 inside the pressure room 621. At the bottom of the through hole 41 of the piston element 4, an air valve element 42 is provided that will be opened and closed synchronously with the up and down movement of piston element 4, thereby achieving the air induction and exhaust for the pressure room 621.

Please also refer to FIG. 7. An air duct 12 is provided all the way from the head element 1 to the bottom of the actuating rod 2, connecting to the through hole 41 of the piston element 4. When the piston element 4 moves downward by pushing the head element 1, the air valve element 42 automatically closes the through hole 42 and the air inside the pressure room 621 is expelled through an outlet hole 6211 configured around the bottom of the pressure room 621. On the other hand, when the pressure on the head element 1 is released and the piston element 4 is raised upward by the resilient element 5, the air valve element 42 automatically opens the through hole 42 and air is drawn into the pressure room 621 via the air duct 12.

The fluid valve element 7 is fixedly positioned at the bottom of the body member 6, sealing the fluid room 622 from the bottom. As shown in FIG. 5, the fluid valve element 7 has a valve body 71 and a valve lid 72. The valve lid 72 is attached to the valve body 71 which has a through hole 712 in the center surrounded by an indented lid seat 711. By flipping the valve lid 72 toward the valve body 71, the valve lid 72 will fit inside the lid seat 711 and seal the through hole 712. As shown in FIG. 8 in which the pump device 10 is tightly installed on a container device B by the enclosure cap 63, the inner pressure inside the container device B is increased when the piston element 4 is pushed downward and the air in the pressure room 621 is forced into the container device B via the outlet hole 6211. The fluid C inside the container device B, therefore, is forced into the dip tube D, pushes open the valve lid 72, enters into the fluid room 622, and then flows out from the discharge spout 61.

Please note that a positioning element 6221 provided inside the fluid room 622 appropriately presses the folded section of the valve lid 72 so that the valve lid 72 normally closes the through hole 712 of the fluid valve element 7 at all times.

As shown in FIG. 9 which is another application of the present invention, the fluid C is stored in a storage member B1 inside the container device B.

The lower portion of the storage member B1 (i.e., the portion close to the bottom of the container device B) is flexible, and the body member 6 of the pump device 10 is fixedly joined to the opening of the storage member B1 on the top. As such, as air is pumped into the container device B, the fluid C in the storage member B1 is ‘squeezed’ out of the storage member B1 literally.

According to the spirit of the present invention, another embodiment of the piston element 4 is shown in FIG. 6, in which the body of the piston element 4 is surrounded with a number of washer rings 40 to provide improved air-tightness as the piston element 4 is moved inside the pressure room 621.

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.

Claims

1. A pump device for use on a container device for dispensing fluid stored in said container device, said pump device comprising an actuating rod, a head element on the top end of said actuating rod, a fastening element, a piston element, a resilient element, a body member, and a fluid valve element, wherein

said body member has a hollow chamber configured on top of an enclosure cap with a discharging spout extended from the outer wall of said chamber; said enclosure cap fastens said pump device to the opening of said container device; said chamber is partitioned into a pressure room and a fluid room;

said pressure room is covered by said fastening element through which said actuating rod is extended; said piston element has a central through hole into which the other end of said actuating rod is embedded; said resilient element is housed inside said pressure room beneath said piston element; an air valve element is provided at the bottom of said through hole that is opened and closed automatically and synchronously with the up and down movement of said piston element; said air valve element is opened to allow air to flow into said pressure room via an air duct running from said head element to the bottom of said actuating rod and connecting to said through hole of said piston element; said air valve element is closed when air is driven out from said pressure room into said container device via an outlet hole; and

said fluid valve element is fixedly positioned at the bottom of said body member, covering said fluid room from the bottom; said fluid valve element has a valve body and a valve lid; said valve lid is attached to said valve body which has a through hole in the center surrounded by an indented lid seat; said valve lid is flipped to fit inside said lid seat and seal said through hole of said fluid valve element; a positioning element provided inside said fluid room appropriately presses the folded section of said valve lid so that said valve lid normally closes said through hole of said fluid valve element.

2. The pump device according to claim 1, wherein corresponding screw threads are provided at the bottom of said head element and around the inner wall of said fastening element respectively, so as to join said head element and said fastening element together when said pump device is not in use.

3. The pump device according to claim 1, wherein fluid of said container device is stored in a storage member inside said container device; said body member of said pump device is fixedly joined to the opening of said storage member on the top; the lower portion of said storage member is flexible; and the fluid in said storage member is squeezed out of said storage member as air is pumped into said container device.

4. The pump device according to claim 1, wherein a plurality of washer rings are provided around the body of said piston element.