Variable flow fluid pump
A pump assembly including a resilient dome attached to a base plate, which together define a chamber. A flapper, supported on a raised center boss on the base plate, seats against a raised annular valve seat to selectively expose fluid inlet apertures in the base plate. The dome has a one-way fluid outlet valve. Dome compression seals the flapper against the valve seat and expels fluid through the fluid outlet valve. Release of the dome allows the outlet valve to close, and the dome regain its original shape, thereby creating a vacuum force that unseats the flapper and draws fluid into the chamber via the fluid inlet apertures. The pump assembly can be made for a variety of fluid densities and viscosities by varying the material and thickness of the flapper, the heights of the valve seat and the center boss, and the size and number of the fluid inlet apertures.
This application claims the benefit of U.S. provisional patent application Ser. No. 60/834,920 filed Aug. 2, 2006, the entire contents of which are incorporated herein by reference.
BACKGROUNDThis invention relates to valves, and more particularly to valves which are adapted to control fluid flow into a chamber of an inflatable bladder.
SUMMARY OF THE INVENTIONThe fluid pump of the invention provides a versatile system capable of pumping fluids having a variety of densities and viscosities. The pump assembly includes a resilient dome attached at its periphery to a base plate, which together define a chamber. The base plate has a raised annular valve seat and a raised center boss which supports a flapper thereon, the flapper capable of sealing against the valve seat to selectively open or close a plurality of fluid inlet apertures in the base plate. A fluid outlet check valve is connected in fluid communication with the dome. Compression of the dome causes the flapper to seal against the valve seat and expels fluid from the chamber out through the fluid outlet valve. Release of the dome enables the fluid outlet valve to close, and enables the dome to return to its original shape, thereby creating a vacuum force that unseats the flapper and draws fluid into the chamber via the fluid inlet apertures. The pump assembly can be made to accommodate a variety of fluid densities and viscosities by varying the material and thickness of the flapper, the respective heights of the valve seat and the center boss, and the size and number of the fluid inlet apertures.
BRIEF DESCRIPTION OF THE DRAWINGSIn the drawings, in which like reference numerals indicate corresponding parts in all views:
A description of the embodiments of the present invention will now be had by way of example, and not limitation, with reference to
Base plate 14 is typically molded from a high durometer thermoplastic material, such as a urethane or an olefin (e.g. ethylene or polypropylene), though, once again, this list of materials is considered merely illustrative, and not limiting. Details of base plate 14 can be seen in
Mounted on the flapper mount 22 is a flapper 16. Flapper 16 is a substantially annular flat disk, typically die cut, from almost any thermoplastic or thermosetting material, including a wide variety of rubbers and silicones, as well as semi-rigid plastic films of various thicknesses. The material of the flapper 16 must be compatible with whatever fluid is being pumped. The thickness and stiffness of the flapper 16 are selected to give a desired response for the particular fluid being pumped.
Connected to a lower portion of the dome 12 that is located within the bladder when the pump is mounted to the bladder is a fluid outlet valve 20 in fluid communication with the pump assembly chamber. Fluid outlet valve 20 is a check valve and may be implemented using a valve such as that disclosed in U.S. Pat. No. 5,564,143. Any suitable check valve known in the art can be used. The outlet valve 20 may lead to an evacuation channel external to film 18 to direct fluid out of the bladder.
As can be seen in
In operation, a user places a digit, such as a thumb or finger, on dome 12 and applies a compressive downward force, shown in
While this invention has been described with reference to one or more embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit or scope of this invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention.
Claims
1. A fluid pump comprising:
- a dome having a flange;
- a base plate secured to the flange at a periphery of the base plate;
- the base plate including a flapper mount for receiving a central portion of a flapper;
- the base including a valve seat for engaging a peripheral portion of the flapper to form a fluid seal;
- the base plate including an inlet aperture positioned beneath the flapper; and
- an outlet valve in fluid communication with the dome.
2. The fluid pump of claim 1 wherein:
- the flapper mount is positioned on a raised boss extending from the base plate.
3. The fluid pump of claim 1 wherein:
- a height of boss versus a height of valve seat is set to control fluid flow through the pump.
4. The fluid pump of claim 1 wherein:
- the inlet aperture includes a plurality of inlet apertures.
5. The fluid pump of claim 4 wherein:
- the size and number of inlet apertures is set to control fluid flow through pump.
6. The fluid pump of claim 1 wherein:
- dome is made from a low durometer thermoplastic material
7. The fluid pump of claim 1 wherein:
- the dome is substantially hemispherical.
8. The fluid pump of claim 1 further comprising:
- a flapper mount extending up from the boss, the flapper mount receiving the flapper.
Type: Application
Filed: Aug 2, 2007
Publication Date: Feb 7, 2008
Inventor: Robert Pekar (Florence, MA)
Application Number: 11/888,796
International Classification: F04B 53/10 (20060101);