Pneumatic chemical pump   

FIELD OF THE INVENTION

The present invention relates to a pneumatic chemical pump, and more particularly to a pneumatic chemical pump that enables a working fluid therein to completely release without forming crystals in a bellows-type container of the pump, so that the bellows-type container may have extended usable life.

BACKGROUND OF THE INVENTION

As shown in FIG. 1, a conventional pneumatic chemical pump 4 includes a pump body 41 having two one-way valves 411, 412, and a bellows-type container 42 located in the pump body 41 and communicating with the two one-way valves 411, 412. The bellows-type container 42 is made of a soft rubber material with a plurality of annular channels 421 sequentially formed on a peripheral wall thereof. When a predetermined amount of a required working fluid has been introduced into the bellows-type container 42 via the one-way valve 411, the working fluid will be released from the pneumatic chemical pump 4 via the other one-way valve 412. Meanwhile, the bellows-type container 42 is compressed to pump out the working fluid.

It is noted the annular channels 421 formed on the peripheral wall of the bellows-type container 42 have a horizontal lower surface each. When the pneumatic chemical pump 4 operates for the bellows-type container 42 to pump out the working fluid, some of the working fluid would become trapped in the horizontal lower surfaces of the annular channels 421. When the pneumatic chemical pump 4 stops operating, the working fluid trapped in the bellows-type container 42 would become dry and form crystals A in the annular channels 421. When the pneumatic chemical pump 4 operates again, the crystals A in the annular channels 421 are squeezed by the compressed bellows-type container 42, and tend to pierce through the soft rubber material of the bellows-type container 42, resulting in holes and cracks on the bellows-type container 42 to shorten the usable life and adversely affect the normal operation of the bellows-type container 42.

SUMMARY

A primary object of the present invention is to provide a pneumatic chemical pump that has a bellows-type container being so configured that a working fluid therein can be completely released without the risk of forming crystals in the bellows-type container to adversely affect the usable life thereof.

To achieve the above and other objects, the pneumatic chemical pump according to the present invention includes a pump body having a base and a cover, and a bellows-type container. The base defines an inner receiving space, and is provided at two opposite sides with first and second one-way valves communicating with the receiving space. The bellows-type container is located in the receiving space in the base of the pump body with a lower open end communicating with the first and second one-way valves. A plurality of internal annular channels and a plurality of external annular channels are alternately formed on a peripheral wall of the bellows-type container. Each of the internal annular channels has a lower surface radially inward and downward inclined toward to the lower open end, so that a working fluid in the bellows-type container can follow the inclined lower surfaces of the internal annular channels to completely flow out of the bellows-type container when the latter pumps.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

FIG. 1 is an assembled sectional view of a conventional pneumatic chemical pump;

FIG. 2 is an exploded perspective view of a pneumatic chemical pump according to a preferred embodiment of the present invention;

FIG. 3 is an assembled view of FIG. 2;

FIG. 4 is a cross sectional view taken along line A-A of FIG. 3; and

FIG. 5 is a cross sectional view showing the pneumatic chemical pump of the present invention in operation.

DETAILED DESCRIPTION

Please refer to FIGS. 2 and 3 that are exploded and assembled perspective views, respectively, of a pneumatic chemical pump according to a preferred embodiment of the present invention, and to FIG. 4 that is a cross sectional view taken along line A-A of FIG. 3. As shown, the pneumatic chemical pump of the present invention includes a pump body 1 and a bellows-type container 2.

The pump body 1 includes a base 11 and a cover 12 assembled together via a plurality of fastening elements 13. The base 11 defines an inner receiving space 111, and is provided at two opposite sides with a first one-way valve 14 and a second one-way valve 15, both of which being communicable with the receiving space 111.

The bellows-type container 2 is located in the receiving space 111 of the pump body 1 with a lower open end communicable with the first and second one-way valves 14, 15. A plurality of internal annular channels 21 and a plurality of external annular channels 22 are alternately formed on a peripheral wall of the bellows-type container 2, such that each of the internal annular channels 21 has a lower surface 211 radially inward and downward inclined toward to the lower open end. And, each of the external annular channels 22 has an elastic member 23 mounted therearound.

Please refer to FIG. 5 that is a cross sectional view showing the pneumatic chemical pump of the present invention in operation. As shown, when the pump is in use, a working fluid 3 is introduced into the first one-way valve 14 of the pump body 1 to thereby upward push a ball 141 disposed in the one-way valve 14. At this point, the working fluid 3 is admitted into the bellow-type container 2. When a predetermined amount of the working fluid 3 has been admitted into the bellows-type container 2, the working fluid 3 produces a pressure to downward push a ball 151 disposed in the second one-way valve 15, so that the working fluid 3 may be released via the second one-way valve 15. At this point, the bellows-type container 2 is brought by a pressure applied thereto to compress, so as to pump out the working fluid 3. Since the internal annular channels 21 of the bellows-type container 2 have a radially inward inclined lower surface 211 each, the working fluid 3 in the bellows-type container 2 will follow the inclined lower surfaces 211 to flow downward and be completely released from the bellows-type container 2 without being retained in the internal annular channels 21. And, when the bellows-type container 2 is compressed, the elastic members 23 separately mounted around the external annular channels 22 are helpful in providing the compressed external annular channels 22 with an increased elastic restoring force, so that the bellows-type container 2 may have an upgraded pumping efficiency.

In brief, when the bellows-type container 2 operates to pump out the working fluid 3, all the working fluid 3 may follow the radially inward inclined lower surfaces of the internal annular channels 21 on the peripheral wall of the bellows-type container 2 to flow downward and be completely released from the container 2. Therefore, no crystals of the working fluid 3 would be formed in the bellows-type container 2, allowing the bellows-type container 2 to have extended service life. As a result, the pneumatic chemical pump according to the present invention is improved and more practical for use than the conventional pneumatic chemical pump.

The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.