BACKGROUND OF THE INVENTION

1 . Field of the Invention

This invention relates to a pump; and more particularly, relates to a centrifugal pump.

2. Description of Related Art

A centrifugal pump cannot begin pumping water until its impeller is immersed in water. In the operation of the centrifugal pump, there are cases in which the impeller is prevented from engaging any water by air entrapped in the pump's housing or body. This situation is known as air lock. In view of this, there is a need for a way to prevent air lock, e.g., in centrifugal pumps.

SUMMARY OF THE INVENTION

To overcome this air lock condition, the pump must release this entrapped air, the air must be allowed to "bleed" out to the atmosphere allowing the water to rise and engage the impeller. By way of example, a related patent application serial no. 14/193,210 (91 1 -17.30-1 //M-RLE-X0006), filed on 28 February 2014, assigned to the assignee of the present application, discloses a technique for solving the

aforementioned air lock problem, which is incorporated by reference in its entirety. See also patent application serial no. 13/917,970, (91 1 -17.28-2//M-RLE-X0005), filed 14 June 2013, which is also assigned to the assignee of the present application, and which is also incorporated by reference in its entirety.

The instant application builds on the techniques set forth in the

aforementioned related applications. By way of example, and according to some embodiments, the present invention may take the form of a pump, including a bilge pump having an impeller and an anti-airlock vent or valve assembly, featuring a pump body and a

pump/strainer assembly.

The pump body includes a pump body portion configured with a vent hole formed therein to allow air entrapped in the pump body to bleed out to atmosphere and allow liquid to fill the pump body in order to get the pump running, and also includes at least one tab receiving portion configured with a rim defining or forming an opening.

The pump/strainer assembly includes a base configured with one or more slots/openings formed therein to receive and/or strain liquid to be pumped, and also includes at least one strainer retaining tab configured with a raised rim to be received in the opening of the at least one tab receiving portion and circumferentially engaged by the rim defining the opening to hold together the pump/strainer assembly and the pump body. The at least one tab receiving portion and at least one strainer retaining tab may also be configured and dimensioned to conceal the vent hole and

substantially prevent the liquid from bleeding through the vent hole and squirting outside of the pump body when the pump is running.

In effect, the strainer retaining tab has a primarily function of holding together the pump body and pump/strainer assembly, while also functioning to conceal the vent hole

According to some embodiments, the present invention may include one or more of the following features:

The at least one tab receiving portion may be configured to receive and flex the at least one strainer retaining tab inwardly, and the at least one strainer retaining tab may be configured to flex outwardly when received in the opening of the at least one tab receiving portion so that the raised rim circumferentially engages the rim defining the opening.

The pump body portion may be molded with the vent hole formed therein. The at least one tab receiving portion may include two tab receiving portions; and the at least one strainer retaining tab may include two strainer retaining tabs, each tab receiving portion configured to receive a respective strainer retaining tab.

The two tab receiving portions may be configured on opposite sides of the pump body; and the two strainer retaining tabs may be similarly configured on opposite sides of pump/strainer assembly.

The pump body may include a pump housing outlet configured at substantially the same level as the vent hole.

BRIEF DESCRIPTION OF THE DRAWING

The drawing, which is not necessarily to scale, include the following Figures:

Figure 1 includes Figs. 1 a and 1 b, where Figure 1 a is a diagram of a pump having a pump body engaged with a pump/strainer assembly, according to some embodiments of the present invention; and where Figure 1 b is a diagram of the pump in Figure 1 a having the pump body not engaged with the pump/strainer assembly, according to some embodiments of the present invention.

Figure 2 includes Figs. 2a and 2b, where Figure 2a is an exploded view of part of the pump in Figure 1 a showing how the air vent hole is concealed when the pump body is engaged with the pump/strainer assembly, according to some embodiments of the present invention; and where Figure 2b is an exploded view of part of the pump in Figure 1 b showing the air vent hole when the pump body is not engaged with the pump/strainer assembly, according to some embodiments of the present invention.

There is a scale of about 2 to 1 between the part of the pump shown in Figure 2 and that shown in Figure 1 .

In the following description of the exemplary embodiment, reference is made to the accompanying drawing, which form a part hereof, and in which is shown by way of illustration of an embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized, as structural and operational changes may be made without departing from the scope of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In summary, in the operation of running a pump, similar to when air is trapped in an upside down glass, the pump cannot begin pumping water until its impeller can engage the water being held back by the "bubble of air". To overcome this problem, entrapped air must be allowed to "bleed" out of the pump housing into the

atmosphere allowing the water to rise into the pump housing and engage the impeller. One solution to this problem is to form an air vent that will allow the entrapped air to bleed out. Once water is flowing because of the air being

evacuated, the vent hole will bleed or squirt water through to the outside of the pump. According to the present invention, because strainer retaining tabs are covering this zone, this bleeding is concealed and stops the water from squirting outside the pump housing.

In particular, and by way of example, Figure 1 shows a pump generally indicated as 10, e.g., which may include, or take the form of, a centrifugal pump having an impeller, such as that typically used as a bilge pump. The pump 10 may include two basic components, i. e., a pump body 12 and a pump/strainer assembly 14.

The pump body 12 includes a pump body portion 12a configured with a vent hole 12b formed therein within the pump body to allow air entrapped in the pump body 12 to bleed out to atmosphere and allow liquid to fill the pump body 12 in order to get the pump 10 running, and also includes at least one tab receiving portion 12c configured with a rim 12d defining or forming an opening 12d'. See also Figure 2. By way of example, the air may be entrapped in a suction chamber generally indicated as 13 of the pump body 12 where the impeller is configured to rotate in order to pump the liquid from the suction chamber, through the pump body 12, to a pump housing outlet 12e, e.g., having a nozzle 16 arranged thereon.

The pump/strainer assembly 14 includes a base 14a configured with one or more slots/openings 14a' formed therein to receive and strain liquid to be pumped into the suction chamber 13, and also includes at least one strainer retaining tab 14b configured with a raised rim 14c to be received in the opening 12d' of the at least one tab receiving portion 12c and circumferentially engaged by the rim 12d defining the opening 12d' to hold together the pump/strainer assembly 14 and the pump body 12, consistent with that shown in Figures 1 a and 2a. The at least one tab receiving portion 12c and at least one strainer retaining tab 14b may also be configured and dimensioned to conceal the vent hole 12b and substantially prevent the liquid from bleeding through the vent hole 12b and squirting outside of the pump body 12 when the pump 10 is running and pumping the liquid. By way of example, the strainer retaining tab 14b may be dimensioned to fit substantially within the opening 12d', so that the rim 12d and the raised rim 14c are in close proximity to one another, consistent with that shown in Figs. 1 a and 2a. The strainer retaining tab 14b extends from the base 14a and is configured to be a flexible component. In operation, when the pump/strainer assembly 14 and the pump body 12 are coupled together, a channel portion 12c' of the tab receiving portion 12c receives and flexes the strainer retaining tab 14b inwardly. The strainer retaining tab 14b then flexes outwardly when received in the opening 12d' of the at least one tab receiving portion 12c so that the raised rim 14c circumferentially engages the rim 12d defining the opening 12d', e.g., in a so-called interference fit. The pump/strainer assembly 14 and the pump body 12 may be de-coupled by pushing the strainer retaining tab 14b inwardly into the opening 12d', so that the rim 12d and the raised rim 14c disengage, the pump/strainer assembly 14 and the pump body 12 are pulled apart, and the strainer retaining tab 14b is pulled out of the channel portion 12c' of the tab receiving portion 12c.

According to some embodiments, the pump body portion 12a may be molded with the vent hole 12b formed therein. The pump housing outlet 12e may be configured at substantially the same level as the vent hole 12b, consistent with that shown in Figure 1 b, for providing the liquid being pumped through a nozzle 16. In Figure 1 , the nozzle 16 is shown being screwed onto the pump housing outlet 12e.

The at least one tab receiving portion 12c may include two tab receiving portions 12c; and the at least one strainer retaining tab 14b may include two strainer retaining tabs 14b, each tab receiving portion configured to receive a respective strainer retaining tab. In Figures 1 -2, only one tab receiving portion 12c and one corresponding strainer retaining tab 14b are shown. The two tab receiving portions 12c may be configured on opposite sides of the pump body 12; and the two strainer retaining tabs 14b may be configured on opposite sides of pump/strainer assembly 14. Embodiments are also envisioned, and the scope of the invention is intended to include, using three or more tab receiving portions 12c and corresponding strainer retaining tabs 14b, e.g., arranged equidistantly around the pump body 12 and the pump/strainer assembly 14.

The pump 10, like that shown in Figure 1 , may also include, e.g., other parts, elements, components, or circuits that do not form part of the underlying invention, including an impeller, a motor, diaphragm pumping components, pressure

transducers, wiring for coupling the motor to a control circuit, and are thus not identified and described in detail herein.

Moreover, pumps having motors and impeller arranged or configured thereon are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof either now known or later developed in the future.

See also another related patent application serial no. 14/193,324 (91 1 -17.32- 1 //M-RLE-X0008), filed on 28 February 2014, showing the same pump as that shown in Figures 1 a and 1 b herein, which discloses a technique for using a duckbill-type check valve for solving a backflow problem, is assigned to the assignee of the present application, and is incorporated by reference in its entirety.

Possible Applications:

Possible applications are envisioned to include any type or kind of pump or rotary equipment that may be submerged and contain trapped air, e.g., in its housing or impeller housing, including but not limited to centrifugal pumps or other types or kinds of submersible pumps either now known or later developed in the future, including bilge pumps or utility pumps.. Scope of the Invention

Although described in the context of particular embodiments, it will be apparent to those skilled in the art that a number of modifications and various changes to these teachings may occur. Thus, while the invention has been particularly shown and described with respect to one or more preferred embodiments thereof, it will be understood by those skilled in the art that certain modifications or changes, in form and shape, may be made therein without departing from the scope and spirit of the invention as set forth above.