This application is a continuation-in-part of U.S. patent application Ser. No. 10/957,585, filed Oct. 5, 2004.
The present invention relates to pumps, and more particularly to electromagnetically driven oscillating pumps.
BACKGROUND OF THE INVENTION
Electromagnetic oscillating pumps are well known in the art. Typically, an electromagnetic coil is utilized to move an armature carried by an impeller relative to the frame assembly of the pump. Upon energization, a bellows-shaped discharge end of the impeller, defining a discharge chamber, is compressed, thereby decreasing the volume of the discharge chamber. This decrease in volume forces the liquid inside the chamber out of the pump through a one-way discharge valve.
Upon de-energization, a spring or permanent magnet returns the impeller to its original position or beyond, thereby increasing the volume of the discharge chamber. As a result, a partial vacuum is created inside the discharge chamber, and liquid is drawn from an inlet end of the impeller, past a center valve, and into the discharge chamber. The electromagnetic coil is then re-energized and the cycle is repeated, thereby producing a stop-and-go flow in one direction.
Currently, the oscillating pumps known in the art use alternation of magnetic polarity as the returning force. Han's U.S. Pat. No. 5,501,581, for example, discloses an electromagnetic oscillating pump using a valve pivotedly connected to a magnetic cylinder. Due to cylindrical shape of the magnetic cylinder, the valve must be connected at substantially single one pivoting point. Under a situation of frequently and periodically movement, the pivot between the valve and magnetic cylinder must tend to fail because of its structural weakness. Furthermore, such pumps as Han must be utilized in a specific direction, which is horizontal with pivot upward just as shown in his drawings. Therefore, the pump disclosed by Han is less useful.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide an electromagnetic oscillating fluid pump, which can be employed in any direction without limits.
Another object of the present invention is to provide an electromagnetic oscillating fluid pump, which avoids using pivoting connection between valve and piston for extending durability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross section of an electromagnetic oscillating fluid pump according to one preferred embodiment of the present invention showing the pump in a static status;
FIG. 2 is a longitudinal cross section showing a first motion status; and
FIG. 3 is a longitudinal cross section showing a second motion status.
DETAILED DESCRIPTION OF THE INVENTION
In order to better understanding the features and technical contents of the present invention, the present invention is hereinafter described in detail by incorporating with the accompanying drawings. However, the accompanying drawings are only for the convenience of illustration and description, no limitation is intended thereto.
Terms such as "top", "bottom", "horizontal", "vertical", "end" and so forth will be used in the description to follow. However, these are relative terms, used for ease of understanding. Whether an element or feature is "above", "under" or at the "end" of another element or feature depends on a particular point of view. Thus, the descriptions are not to be read as restrictive on the invention.
Referring first to FIG. 1, an electromagnetic oscillating fluid pump in accordance with one embodiment of the present invention is illustrated. The pump includes a housing 1 which is a hollow cylinder to accommodate other elements. An air inlet 13 and an air outlet 11 are arranged at the centers of two end sides of the housing, respectively. Two annular electromagnetic coils 21, 22 are fixed at two ends of the housing 1, respectively. The hollow centers of the electromagnetic coils 21, 22 form air passages 211, 221, respectively. The air passages 211, 221 are corresponding to the air inlet 13 and air outlet 11. A piston 3 is slidably disposed between the two electromagnetic coils 21, 22. A control circuit (not shown) electrically couples the two electromagnetic coils 21, 22 to change their magnetic polarity.
The piston 3 made of a permanent magnet is of a disk shape. Thus, its magnetic polarity appears in a direction of upside and downside. A first valve hole 31 is formed at the center of the piston 3 to slidably receive a first valve 30. The first valve 30 is of a T shape composed of two perpendicular main bars 301, 302 and one tail bar 303. The horizontal main bar 301 is parallel to and longer than the tail bar 303. A gap 304 is defined between the vertical main bar 302 and the first valve hole 31 for allowing air to pass through. There may be one or more through holes 305 around the first hole and under the horizontal main bar 301 for satisfying requirement of a larger quantity of air passing the first valve 30. Additionally, a second valve 12, which has the same outline as the first valve 30, can be disposed in the second valve hole 10 at upper end of the housing 1. The second valve 12 can prevent air pushed by the piston 3 from directly spouting out.
The space between the two electromagnetic coils 21, 22 is substantially the reciprocating space of the piston 3. When the electromagnetic coil 21, 22 are magnetically energized, the piston 3 can be reciprocatingly driven by the magnetism.
FIGS. 2 and 3 illustrate the operation of the electromagnetic oscillating fluid pump. Here, we assume that upside of the piston, which is adjacent to the first electromagnetic coil 21, is a north (N) pole, while the downside is a south (S) pole. Before the piston 3 starts reciprocating, the piston 3 is located more adjacent to the electromagnetic coil 21, and the first valve 30 and second valve 12 are both closed. A control circuit (not shown) controls both the lower half of the first electromagnetic coil 21 and the upper half of the second electromagnetic coil 22 to be N pole. At this time, the piston 3 is magnetically driven by the electromagnetic coils 21, 22 to move downward. When the piston 3 moves towards the second electromagnetic coil 22, air pressed by the piston 3 pushes the first valve 30 to move upward. In other words, the first valve 30 is opened so that air can passes through the gap 304 and the through holes 305.
After that, the control circuit controls the magnetic elements 21, 22 to change their magnetic polarity, i.e. both the lower half of the first electromagnetic coil 21 and the upper half of the second electromagnetic coil 22 to be S pole. Thus, the piston 3 is magnetically driven by the electromagnetic coil 21 to move upward. When the piston 3 moves towards the first magnetic element 21, similarly to the first valve 30, air pressed by the piston 3 pushes the second valve 12 to move upward. Therefore, air can pass through the second valve hole 10 to spout out of the air outlet 11.
Since, any person having ordinary skill in the art may readily find various equivalent alterations or modifications in light of the features as disclosed above, it is appreciated that the scope of the present invention is defined in the following claims. Therefore, all such equivalent alterations or modifications without departing from the subject matter as set forth in the following claims is considered within the spirit and scope of the present invention.