Abstract:
An air pump including an outer housing and an inner housing positioned within the outer housing, the inner housing and outer housing defining an air conduit therebetween, a motor positioned within the inner housing, a vane occupying a majority of the fluid conduit, and an impeller positioned within the fluid conduit and connected to the motor. The outer housing is adapted to couple to an inflatable bladder. In some embodiments, a majority of the pump and a valve assembly is positioned within the bladder.

Description:
The present patent application claims priority to U.S. Provisional Patent Application Nos. 60/280,257 and 60/280,040, both filed on Mar. 30, 2001, and is a Continuation-In-Part of U.S. patent application Ser. No. 09/859,706, filed May 17, 2001, and is a Continuation-In-Part of International PCT Application No. PCT/US01/15834, filed May 17, 2001. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention is related to pumps and, more specifically, to pumps for use with inflatable devices. 
     2. Related Art 
     A variety of methods of providing air or other fluids to inflatable devices have been proposed. Typically a pump is used to supply air to an orifice in the inflatable device. Such pumps may include a motor that drives an impeller, moving the air into the inflatable device. Motorized pumps may be powered by electricity. Typically, such electricity is provided by a connection to standard house current or, where portability is desired, by batteries. 
     SUMMARY 
     According to one embodiment of the present invention, a pump is provided. The pump includes an outer housing and an inner housing positioned within the outer housing and defining a fluid conduit between the inner housing and the outer housing. The pump also includes a motor positioned within the inner housing, a vane occupying a majority of the fluid conduit, and an impeller positioned within the fluid conduit and connected to the motor. 
     According to one embodiment of the present invention, an inflatable device is provided. The inflatable device includes a substantially fluid impermeable bladder, a valve assembly, and a hand holdable pump detachably connected to the valve assembly. In this embodiment, a majority of the hand holdable pump and valve assembly are positioned within the bladder. 
     According to one embodiment of the present invention, a pump is provided. The pump includes an outer housing, an inner housing positioned within the outer housing and defining a fluid conduit between the inner housing and the outer housing, and a motor positioned within the inner housing. In this embodiment, the average distance between an inner surface of the outer housing, and an outer surface of the inner housing is less than about 25% of the average diameter of the outer housing. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The foregoing and other advantages of the present invention will be more fully appreciated with reference to the following drawings in which: 
         FIG. 1  is a cross-sectional, elevational view of a pump according to one embodiment of the present invention; 
         FIG. 2  is an axial, elevational view of the pump of  FIG. 1 ; 
         FIG. 3  is a cross-sectional, elevational view of a pump according to another embodiment of the present invention; 
         FIG. 4  is a perspective, elevational view of one aspect of the present invention; 
         FIG. 5  is a side view of a pump according to one embodiment of the present invention; 
         FIG. 6  is an exploded view of the pump of  FIG. 6 ; 
         FIG. 7  is an exploded view of one aspect of the present invention; 
         FIG. 8  is a cut-away view of the aspect of  FIG. 7 ; and 
         FIG. 9  is a cross-sectional view of the aspect of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     The present invention is directed to a pump with an axial fluid conduit. In one embodiment, the pump of the present invention may include an outer housing and an inner housing positioned within the outer housing. The axial fluid conduit may be defined between the inner housing and the outer housing. A motor may be positioned within the inner housing and an impeller positioned within the fluid conduit and connected to the motor. 
     Referring now to the figures, and, in particular, to  FIGS. 1–2  and  5 – 6 , one embodiment will be described. In this embodiment, the pump  10  may include an outer housing  20  and an inner housing  30  positioned within outer housing  20 . A fluid conduit  40  may be defined between outer housing  20  and inner housing  30 . A motor  50  may be positioned within inner housing  30  and an impeller  60  positioned within fluid conduit  40  and connected to motor  50 . The connection may be any attachment known to those of skill in the art. 
     Outer housing  20  may be constructed in any manner and of any material(s) that render pump  10  sufficiently durable for its intended application and provide a suitable outer wall for fluid conduit  40 . For example, outer housing  20  may be constructed of a lightweight, inexpensive, durable, and fluid-tight material. Outer housing  20  may also be shaped such that it is not cumbersome. For example, outer housing  20  may be ergonomically designed. Materials for construction of outer housing  20  include a wide variety of relatively rigid thermoplastics, such as polyvinyl chloride (PVC) or acrylonitrile-butadiene-sytrene (ABS). However, outer housing  20  may also be constructed of other materials, such as metals, metal alloys, and the like. 
     Outer housing  20  may be constructed in any shape capable of containing an inner housing  30 . For example, outer housing  20  may be constructed generally cylindrically. In some embodiments, outer housing  20  may be larger (e.g., have a larger diameter) where it contains inner housing  30 , and smaller (e.g., have a smaller diameter) at an inlet  22  and an outlet  24  of outer housing  20 . It should be understood that inlet  22  and outlet  24  have been labeled arbitrarily and that fluid can be moved through pump  10  in either direction. For example, pump  10  may be operated in a first direction to push air from inlet  22  to outlet  24  or in a second direction to pull air from outlet  24  to inlet  22 . 
     Inlet  22  may be constructed to facilitate air flow into fluid conduit  40 . For example, inlet  22  may be constructed to prevent blockage of inlet  22 . In one embodiment, inlet  22  includes protrusions  26  to inhibit blockage of inlet  22 . Inlet  22  may also be constructed to prevent foreign objects from contacting impeller  60 . For example, inlet  22  may be constructed to have multiple small openings that are relatively difficult for a foreign object, such as a finger, to enter. In a preferred embodiment, protrusions  26  of inlet  22  are constructed as slats, inhibiting foreign objects from contacting impeller  60 . 
     Outlet  24  may be constructed to provide fluid to a desired location. For example, outlet  24  may be constructed to provide fluid to an inflatable device. In one embodiment, outlet  24  includes structure to lock to an inlet of an inflatable device and to bias a valve of the inlet to an open position when the pump is moving fluid to the inflatable device. In another embodiment, the pump may include a solenoid to bias open the valve when the pump is adding fluid to, drawing fluid from, the inflatable device. 
     Inner housing  30  may also be constructed in any manner and of any material(s) that are suitable for containment within outer housing  20 , for serving as the inner wall of fluid conduit  40  and for containing motor  50 . For example, inner housing  30  may be constructed to fit within outer housing  20 , so as to provide the fluid conduit  40 . In one embodiment, inner housing  30  is constructed such that it is evenly spaced from an inner surface of outer housing  20 . The shape of inner housing  30  may be selected to be compatible with the shape of outer housing  20 . For example, where outer housing  20  is generally cylindrical, inner housing  30  may also be generally cylindrical. 
     Inner housing  30  may also be constructed to securely contain motor  50 . For example, inner housing  30  may include internal structure to maintain motor  50  in a desired location. Inner housing  30  may include structure to hold motor  50  in a desired location without allowing undesired vibration or noise. In one embodiment, inner housing  30  may also be constructed to contain one or more batteries to provide electrical power to motor  50 . Inner housing  30  may be constructed of any material(s) sufficiently durable to contain motor  50  and suitable for use with the fluid to be pumped. For example, inner housing  30  may be constructed out of any of the same materials as outer housing  20  described supra. 
     Fluid conduit  40  may be defined by the construction of outer housing  20  and inner housing  30 . Fluid conduit  40  may provide sufficient space for fluid flow, so as not to create a significant pressure drop. Fluid conduit  40  may also be regular in shape and substantially free of irregularities that may interfere with efficient fluid flow, potentially creating turbulence, noise and pressure loss. 
     Fluid conduit  40  may include structure to improve the flow of fluid through fluid conduit  40  and enhance pressurization. Improving the flow through fluid conduit  40  may decrease turbulence and generally result in a pump that is quieter and more efficient. Flow is preferably directed such that the fluid is not forced to make any sudden changes in direction. Fluid conduit  40  is generally axial in direction and impeller  60  will generally impart a rotational force on the fluid relative to the axis of fluid conduit  40 . Accordingly, any structure included to improve the flow of fluid through fluid conduit  40  is preferably constructed so as to not inhibit the generally axial movement of fluid through fluid conduit  40 , and may allow for the rotation of fluid within fluid conduit  40 . 
     Inefficient fluid flow is preferred to be avoided throughout the length of fluid conduit  40 . Accordingly, in a preferred embodiment, the pump is provided with structure to improve the flow of fluid through fluid conduit  40  and enhance pressurization, the structure occupying a majority of fluid conduit  40 . The structure for improving the fluid flow preferably occupies at least 75% of the length of fluid conduit  40 , even more preferably 90% of the length of fluid conduit  40 , and most preferably substantially all of the length of fluid conduit  40 , improving flow throughout fluid conduit  40 . By way of illustration, what is meant by the structure occupies a majority of fluid conduit  40  is that the structure extends at least half way through the length of fluid conduit  40 , not that it fills more than half the void space in fluid conduit  40 . A structure occupying the majority of fluid conduit  40  is substantially different from an arrangement that simply directs fluid from an impeller into an open fluid conduit because it controls the fluid flow through a greater portion of fluid conduit  40  and thus is better able to improve fluid flow. 
     In one embodiment, structure to improve the flow of fluid through fluid conduit  40  and enhance pressurization includes one or more structures that direct flow of fluid. For example, referring to  FIGS. 3–4  and  6 , fluid conduit  40  may include vanes  70  shaped to improve fluid flow through fluid conduit  40 . Vanes  70  may be constructed to direct fluid flow within fluid conduit  40  and to bridge fluid conduit  40  from an inner surface of outer housing  20  to an outer surface of inner housing  30 , forcing fluid to flow through the channels defined by the vanes. However, it should be understood that vanes  70  need not extend between the inner surface of outer housing  20  and the outer surface of inner housing  30  in all embodiments, or throughout the entire fluid conduit in such embodiments where they do so extend. 
     Vanes  70  may be constructed to minimize any abrupt changes in fluid flow associated with inefficient flow and increased pressure drop. For example, vanes  70  may be swept in a direction of the rotation imparted by impeller  60 , and may direct the flow generally axially along fluid conduit  40 . As illustrated, in one embodiment, vanes  70  straighten along the length of fluid conduit  40 , allowing them to gradually redirect the air from primarily rotational movement to primarily axial movement. Vanes  70  are preferably free of any rough edges or dead end pockets that may increase fluid resistance. 
     It should be appreciated that structure to improve the flow of fluid through fluid conduit  40  and enhance pressurization may be particularly useful where fluid conduit  40  is relatively narrow. For example, where it is desired to make pump  10  portable, yet powerful, it may be desired to make inner housing  30  relatively large to house a larger motor, while making outer housing  20  relatively small to reduce the overall size of the device. In such an embodiment, fluid conduit  40  may be relatively narrow. For example, the average distance between an inner surface of outer housing  20  to an outer surface of inner housing  30  may preferably be about 25%, more preferably about 10%, even more preferably about 5%, or less of the average diameter of outer housing  20 . In the illustrated embodiment, the average distance between the inner surface of outer housing  20  to the outer surface of inner housing  30  is about 8% of the average diameter of outer housing  20 . The narrowness of fluid conduit  40  may itself act as a structure to improve the flow of fluid, directing it axially along the fluid conduit, rather than allowing it to enter a relatively open area. Accordingly, a narrow fluid conduit may be sufficient is some embodiments to reduce inefficient flow. 
     Fluid conduit  40  may also include structure to maintain the shape of fluid conduit  40 . For example, fluid conduit  40  may include structure to secure inner housing  30  relative to outer housing  20 . In one embodiment, this structure may include one or more struts connecting an inner surface of outer housing  20  to the outer surface of inner housing  30 . In another embodiment, one or more vanes  70  serve to both direct the fluid flow and maintain the relationship between the inner and outer housings. 
     Motor  50  may be any device capable of rotating impeller  60  to produce fluid flow through pump  10 . For example, motor  50  may be a conventional electric motor. In one embodiment, motor  50  is preferably an efficient, lightweight motor. Motor  50  may also be relatively small, to reduce the overall size of pump  10 . However, it is to be appreciated that even for a small overall size pump, the motor may still be relatively large compared to the overall size of the pump where it is desired to provide more pumping power. 
     Impeller  60  may be constructed in any manner and of any material(s) that allow impeller  60  to move fluid when rotated by motor  50 . For example, impeller  60  may be constructed with fins  62  capable of forcing fluid into or out of pump  10 , depending on the direction of rotation of impeller  60 . Impeller  60  may be made of any material capable of maintaining a desired shape of impeller  60 . For example, impeller  60  may be constructed of durable and lightweight material that is compatible with the fluid to be used in pump  10 . For example, impeller  60  may be constructed of a thermoplastic, such as those mentioned for use in construction of outer housing  20 . 
     Referring to  FIGS. 7–9 , according to the present invention pump  10  may be used in a variety of ways. For example, pump  10  may be an independent device, such as a hand holdable pump, and may be placed in contact or connected with an inflatable device when it is desired to inflate the device, typically at a valve  110 . In another embodiment, pump  10  may be incorporated into the inflatable device, detachably or permanently. One example embodiment of a pump  10  according to the present invention will now be described with reference to  FIGS. 7–9 . 
     In the example embodiment, pump  10  may be connected to a substantially fluid impermeable bladder  120  in an inflatable device. Where pump  10  is connected to bladder  120 , pump  10  may be configured so that it does not interfere with the use of the inflatable device. For example the inflatable device may be constructed with pump  10  recessed into bladder  120 , as illustrated in  FIGS. 7–9 . Where pump  10  is recessed within bladder  120 , it is an advantage of this embodiment that pump  10  will not interfere with the use of the inflatable device. For example, the exterior profile (total volume and shape) of pump  10  and the inflated device in combination may be substantially the same as the exterior profile of the inflated device absent the combination, thus reducing the opportunity for pump  10  to impact or interfere with the use of the inflatable device. For example, where pump  10  is located within bladder  120  in a mattress application, it allows an inflatable standard sized mattress to fit into a standard sized bed frame. Where pump  10  is located within bladder  120 , it may be sized such that it will not come into contact with bladder  120  when bladder  120  is inflated, except at the point(s) of connection. Accordingly, the pump of the present invention, which may be constructed so as to be small and hand-holdable, may be useful in such an application. For additional information regarding incorporating pumps at least partially within a bladder, see U.S. patent application Ser. No. 09/859,706, which is hereby incorporated by reference in its entirety. 
     An embedded pump  10  may be powered by conventional household current or by battery power. It should also be understood that pump  10  can be a hand holdable pump that is detachable from the inflatable device and is configured to mate with the inflatable device and to be embedded substantially within the bladder. 
     Outer housing (comprising two portions  20   a  and  20   b ) may house other structure in addition to inner housing (comprising two portions  30   a  and  30   b , and corresponding vanes comprising two portions  70   a  and  70   b ) and motor  50 . For example, outer housing may include fluid control structure such as valves. Valves may be operated manually, by using a solenoid, or using other conventional techniques. The structure to operate the valve may also be included within outer housing  20   a  and  20   b.    
     Having thus described certain embodiments of the present invention, various alterations, modifications and improvements will be apparent to those of ordinary skill in the art. Such alterations, variations and improvements are intended to be within the spirit and scope of the present invention. Accordingly, the foregoing description is by way of example and is not intended to be limiting. The present invention is limited only as defined in the following claims and the equivalents thereto.