US20060073040A1

US20060073040A1 - Air pump for an inflatable product

Info

Publication number: US20060073040A1
Application number: US10/954,718
Authority: US
Inventors: Andrew Metzger; Lauren Worley; Shin Wu
Original assignee: Coleman Co Inc
Current assignee: Coleman Co Inc
Priority date: 2004-09-30
Filing date: 2004-09-30
Publication date: 2006-04-06

Abstract

A dry cell air pump that provides in excess of ten inches water column in pressure. A motor is used that draws fewer amps than prior art motors, yet operates at higher revolutions per minute. The small motor is capable of providing a high speed of rotation with relatively low torque, especially in comparison to prior art motors. To offset the low torque, a high efficiency fan is provided that rotates at high speeds, yet produces high air volume and pressure with reduced turbulence. The fan includes upper and lower walls enclosing the blades for the fan. The upper and lower walls minimize turbulence and maximize efficiency of the fan, providing a maximal tip velocity of the fan and thus increased pressure for the dry cell air pump. The fan includes a series of dimples along its upper surface that reduce back flow in the fan housing.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention is directed to air pumps, and more specifically to air pumps for inflatable products.

BACKGROUND OF THE INVENTION

An airbed is a large rectangular rubber or plastic bag that is filled with air so that it may be used as a bed. An airmat is similar in construction to an airbed, but is used as a float so that an individual may lie on the airmat on the water. Both products fall under the broad category of “inflatable” products. Other nonlimiting examples of inflatable products include rafts, inflatable furniture, inflatable pools, and inflatable boats.
One thing inflatable products have in common is that they must be inflated for use. To this end, a valve or valves are supplied on each inflatable product for a user to provide air or another gas into the inflatable product. The user may utilize his or her breath, i.e., by blowing into a valve or valves, or may utilize a manual or electric pump. More often, for larger inflatable products, such as airbeds or inflatable boats, a pump is used.
Electric pumps for inflatable products generally fall into three categories: alternating current (AC) pumps, which are supplied electricity through an electrical outlet; rechargeable pumps, which have rechargeable batteries that are recharged as needed; and pumps that utilize dry cell non-rechargeable direct current (“DC”) batteries (“dry cell air pumps”). The dry cell air pumps are popular, because they are relatively inexpensive and dry cell batteries are easy to obtain. One popular model utilizes four D-cell batteries. An example of such a model is shown in U.S. Design Pat. No. D445,804.
Although the dry cell air pumps for the most part work well for their intended purpose, often they are limited in that they may not be able to supply a sufficient amount of pressure to adequately inflate larger inflatable products. For example, large airbeds, such as double-high airbeds, often require a large volume of air at high pressure to provide sufficient firmness for some individuals.
Manufacturers have tried to address air pressure problems by providing as large of a motor as possible, given the voltage provided by the batteries. As an example, a four D battery dry cell air pump has six volts of dry cell power. One prior art four D dry cell air pump utilizes a six volt motor drawing 7.8 amps. In practice, it has been observed that 7.8 amps is too much of a draw on the motor, and the four D dry cell batteries can not maintain six volts and 7.8 amps, and more realistically produce four volts at approximately 3.5 amps. Thus, the results are that the motor runs too slowly, or that the batteries are stressed.
The applicants are aware of prior art dry cell air pumps that have produced up to eight inches of water column (in WC) in pressure. Although eight in WC may produce firmness that is sufficient for some users of airbeds, there are users who desire a more firm airbed.

SUMMARY OF THE INVENTION

The following presents a simplified summary of some embodiments of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some embodiments of the invention in a simplified form as a prelude to the more detailed description that is presented later.
In accordance with an embodiment, a dry cell air pump is provided that provides in excess of ten inches water column in pressure. The dry cell air pump utilizes, in one embodiment, four D cell batteries.
In accordance with an embodiment, a motor is used that utilizes less voltage than available from the batteries in the pump, allowing the motor to run at maximum efficiency. In one embodiment, a 4.0 volt motor is used with four D cell batteries. The small motor is capable of providing a high speed of rotation (e.g., 24,000 RPM's when loaded). However, the low voltage of the motor results in relatively low torque, especially in comparison to prior art motors. To offset the low torque, a high efficiency fan is provided that produces high air volume and pressure with little turbulence. The fan includes upper and lower walls enclosing the blades for the fan. The upper and lower walls minimize turbulence and maximize efficiency of the fan, providing a maximal tip velocity of the fan and thus increased pressure for the dry cell air pump, with very little torque requirement from the small electrical motor.
In accordance with an embodiment, the fan includes a series of dimples along its upper surface. These dimples align with grooves in an upper part of the fan housing of the dry cell air pump. The engagement of the dimples with the grooves minimizes pressure loss and back air flow by interrupting air that attempts to flow backward along the top of the fan.
Other features of the invention will become apparent from the following detailed description when taken in conjunction with the drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of a dry cell air pump incorporating an embodiment of the invention;
FIG. 2 is an exploded perspective view of the dry cell air pump of FIG. 1;
FIG. 3 is a cross sectional view taken along the section lines 3-3 of FIG. 5;
FIG. 4 is a side perspective view of a finger guard that may be used with the dry cell air pump of FIG. 1 in accordance with an embodiment of the invention; and
FIG. 5 is an exploded side perspective view of an upper portion of the fan housing of the fan for the dry cell air pump of FIG. 1.

DETAILED DESCRIPTION

In the following description, various embodiments of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described.
Referring now to the drawings, in which like reference numerals represent like parts throughout the several views, FIG. 1 shows a dry cell air pump 20 in accordance with an embodiment of the invention. Some aspects of the present invention may be utilized with electric pumps or manual pumps, but throughout this disclosure, the embodiments will be described with respect to a dry cell air pump, specifically the dry cell air pump 20.
The dry cell air pump 20 includes a motor housing 22 underneath a fan housing 24, although the two housings may be arranged differently, or may be provided as a single structure. In the embodiment shown, four D cell batteries 26 are mounted within the motor housing 22 and about a motor 28. A switch 30 is provided on the outside of the motor housing 22 for turning on and off operation of the dry cell air pump 20. The D cell batteries 26 are removable from the motor housing 22 via a removable battery pan 32. Latches 34 are provided for releasing and attaching the battery pan 32 to the bottom of the motor housing 22. As such, the battery pan 32 may be removed to provide access to the inside of the motor housing 22 so that the D cell batteries 26 may be replaced. Contacts 36 are provided inside the motor housing 22 for providing power from the D cell batteries 26 to the motor 28 in accordance with operation of the switch 30 in a manner known in the art.
In the embodiment shown, the fan housing 24 is formed by a fan cover 48 fitting over the motor housing 26. The fan cover 48 is shaped so that, when it fits over the motor housing 26, an internal air chamber 50 (shown generally in FIG. 2) is formed. A fan 52 is mounted within the air chamber 50 for rotation by the motor 28. An outlet 54 is positioned at one edge of the air chamber 50 for permitting flow of air out of the air chamber 50, for example into an inflatable product via a flexible conduit (not shown, but known in the art). An inlet 55 is provided on the top of the fan housing 24 through which air is drawn into the fan 52, which in turn is blown out through the outlets 54.
Details of the fan 52 can be seen in FIG. 3. The fan 52 includes a lower wall 56 and an upper cover 58. The upper cover 58 serves as a wall that extends adjacent to the upper portion of the fan 52. Blades 60 extend between the lower wall 56 and the cover 58 from a position spaced from a central access of the fan 52 outward to outer edges or tips of the fan 52. An air inlet 62 is positioned centrally in the cover 58 and is in fluid communication with the blades 60. In operation, the motor 28 rotates the fan 52 so that air is drawn through the inlet 55 in the fan housing 24 and down into the air inlet 62 of the fan. This air is then blown through the blades 60 and out of the tips of the fan 52. The lower wall 56 and the upper cover 58 direct the majority of the air outward, in a more efficient manner than current designs.
In accordance with an embodiment, the motor 28 utilizes less voltage than available from the batteries 26, allowing the motor to run at maximum efficiency. In one embodiment, a 4.0 volt motor is used with four D cell batteries. For example, a Nichibo DC Motor, Model number LD3FN-5015B-C/58, produced by Nichibo Taiwan Corporation, Taipei, Taiwan, may be used, which has a maximum torque of 32.975 Amps and is capable of providing a high speed of rotation (24,200 RPM's with no load). However, the low voltage of the motor results in relatively low torque, especially in comparison to prior art motors. To offset the low torque, the high efficiency fan 52 is utilized that produces high air volume and pressure with less turbulence.

Applicants have found that such a motor 28, when operating with the fan 52, can produce a significant amount of pressure out of the outlet 54 of the fan housing 24. This pressure is provided in part because the motor 28 has sufficient power from the four D cell batteries 26 and in part because the fan 52 is a stable structure that is capable of rotating at high revolutions per minute, for example when loaded at approximately 14,000 revolutions per minute. By rotating the fan 52 at high speed, the tip velocity of the fan 52 is increased, thereby increasing the pressure of the air flowing out of the outlet 54 of the fan housing 24. Applicants have found that utilizing the motor 28 described herein and a fan 52 having the following dimensions:



Diameter	68.2	millimeters
Height	8.5	millimeters
Outer Slope of Upper Cover	7	degrees
Air Inlet Opening Diameter	24.818	millimeters
Total Wieght	0.024	pounds

that a pressure of at least 10 inches of water can be provided and up to at least 12 inches of water. Utilizing such a structure, the dry cell air pump 20 is capable of inflating a double-high queen sized airbed in less than four minutes, with the airbed having significant firmness. Applicants are not aware of any prior art non-rechargeable dry cell air pump 20 that is capable of generating this type of air pressure, and particularly is not aware of four D cell battery models that are capable of producing this type of air pressure.

In accordance with an embodiment, the cover 58 of the fan 52 includes dimples 64 positioned about the cover 58 of the fan 52. The dimples 64 reduce pressure loss during rotation of the fan 52, and reduce back air flow. As discussed above, in operation of the dry cell air pump 20, air is blown out of the outlet 54. As an inflatable product is filled, there is some air pressure push back from the inflatable product. The air that is push back-attempt to try to go over and under the fan. The air at the bottom of the fan 52 stabilizes, but the air at the top of the fan 52 attempts to go out the outlet 55 of the fan housing. It is believed that the dimples 64 partially block this travel of air to the outlet 55, thus reducing back flow.
In accordance with an embodiment, an aerodynamic finger guard 70 (FIG. 4) is provided for the dry cell air pump 20. The finger guard 70 may be used at the outlet 54, the inlet 55, or both. The finger guard 70 includes a structure for blocking a finger or a foreign object from entering the outlet 54 and/or the inlet 55. In the embodiment shown, the structure is an “X” 72, but other structures may be provided. In accordance with an embodiment, the structure blocking the user's finger or other foreign objects from entering the outlet 54 and/or the inlet 55 is shaped in an air foil design, minimizing turbulence for air flowing past the structure. As such, air flow volume and air pressure drop over the finger guard 70 is minimized.
Other variations are within the spirit of the present invention. Thus, while the invention is susceptible to various modifications and alternative constructions, a certain illustrated embodiment thereof is shown in the drawings and has been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. An air pump, comprising:

at least one battery, said at least one battery producing approximately six or less volts;

a motor connected to the battery;

a fan connected to the motor for rotation thereby; and

an air outlet in fluid communication with the fan;

the motor and the fan being configured to produce at least approximately ten inches water column in pressure at the air outlet.

2. The air pump of claim 1, wherein the motor and the fan are configured to produce at least approximately twelve inches water column in pressure.

3. The air pump of claim 1, wherein the fan comprises:

a first wall;

a second wall; and

blades extending between the first wall and the second wall.

4. The air pump of claim 3, wherein the fan further comprises an air inlet on the first wall and protrusions on the first wall.

5. The air pump of claim 4, further comprising a fan housing in which the fan rotates, and wherein the fan housing includes groves for receiving the protrusions when the fan is rotating in the fan housing.

6. The air pump of claim 1, wherein said at least one battery comprises four 1.5 volt dry cell batteries.

7. The air pump of claim 6, wherein the four 1.5 volt dry cell batteries each comprise a D-cell battery.

8. The air pump of claim 6, wherein the motor is rated for less than 6 volts.

9. The air pump of claim 8, wherein the motor is rated for approximately 4 volts.

10. The air pump of claim 1, wherein the motor is rated for less than 6 volts.

11. The air pump of claim 10, wherein the motor is rated for approximately 4 volts.

12. An air pump, comprising:

at least one battery, said at least one battery producing approximately six volts;

a motor connected to the battery and having a rated voltage of less than six volts;

a fan connected to the motor for rotation thereby and comprising:

a first wall;

a second wall; and

blades extending between the first wall and the second wall.

13. The air pump of claim 12, wherein the motor and the fan are configured to produce at least approximately ten inches water column in pressure.

14. The air pump of claim 13, wherein the motor and the fan are configured to produce at least approximately twelve inches water column in pressure.

15. The air pump of claim 12, wherein the fan further comprises an air inlet on the first wall and protrusions on the first wall.

16. The air pump of claim 15, further comprising a fan housing in which the fan rotates, and wherein the fan housing includes groves for receiving the protrusions when the fan is rotating in the fan housing.

17. The air pump of claim 12, wherein said at least one battery comprises four 1.5 volt dry cell batteries.

18. The air pump of claim 17, wherein the four 1.5 volt dry cell batteries each comprise a D-cell battery.

19. The air pump of claim 12, wherein the motor is rated for approximately 4 volts.

20. An air pump, comprising:

a motor;

a fan connected to the motor for rotation thereby and comprising:

a first wall;

blades extending from the top wall; and

an air inlet on the first wall and protrusions on the first wall.

21. The air pump of claim 20, further comprising a fan housing in which the fan rotates, and wherein the fan housing includes groves for receiving the protrusions when the fan is rotating in the fan housing.

22. The air pump of claim 20, wherein the fan further comprises a second wall, and the blades extend between the first and second walls.

23. An air pump comprising:

a finger guard at one of an outlet and an inlet for the air pump, the finger guard including a structure for blocking a finger or a foreign object from entering said one of the outlet and the inlet, and the structure being shaped in an air foil design.

24. The air pump of claim 23, wherein the structure comprises an “X” shape.