Abstract:
A pumping system and related methods involving an outer chamber and an inner chamber extending between two endplates, wherein the circumference of the inner chamber may be adjusted via a plurality of ribs and linear motors.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   The present application is a US Non-Provisional Patent Application of and claims the benefit of priority from commonly owned and co-pending U.S. Provisional Patent Application Ser. No. 60/497,806 (filed Aug. 25, 2003) and Ser. No. 60/497,836 (filed Aug. 25, 2003), the entire contents of which are hereby expressly incorporated by reference into this disclosure as if set forth fully herein. 

   BACKGROUND OF THE INVENTION 
   I. Field of the Invention 
   The present invention relates generally to pumps and, more particularly, to pumping system and related methods involving an outer chamber and an inner chamber extending between two endplates, wherein the circumference of the inner chamber may be adjusted via a plurality of ribs and linear motors. 
   II. Discussion of the Prior Art 
   Pumps have been used for centuries, and various types of pumps have been devised, including positive displacement pumps, rotary pumps, vane pumps, and centrifugal pumps. While many of these pumps are well suited for particular uses, pumps in general do not have a high efficiency, and are not well suited for special applications, such as pumping blood or pumping sewage wastewater. 
   Current pumps include the crew of Archimedes that interferes with axial blood flow. Many pumps cause damage to the blood components as these blood components make either direct or near contact that surfaces of the pump. Ventricular assist pumps currently employ mechanisms to move blood that stresses the blood in some situations and are non-pulsatile. 
   When pumping blood, constant flow by conventional pumps may cause “pumphead” because of the sustained vasodilation. The alterations in the cellular components of the blood, typical with rotary and constant flow pumps, may be due to reactions with the vasodilated capillaries and the components of the blood reacting to this abnormal state. Ischemia may be present to the decreased lumen secondary to an accumulation of platelets and/or the blood not pulsing enough to create turbulence and transfer the gases and nutrients. This would thus be analogous to going too fast by a road sign. It may be due to the hemodynamics of fluid flow with a non-newtonian fluid. The pulse flow preferably allows for a psychological pause in the short duration dilated phase and the contraction may facilitate the movement of the blood components. 
   Various types of linear pumps have been devised, including linear pumps particularly intended for pumping blood. U.S. Pat. Nos. 5,676,162 and 5,879,375 disclose reciprocating pump and linear motor arrangements for pumping blood. The assembly includes a piston-valve which is placed at the inlet end of a hollow chamber. The valve leaflets may be in any arbitrary position. The pump module arrangement may occupy a space of no more than approximately 6 cm. in diameter and 7.5 cm. long. In a preferred embodiment, a quick connect locking system may be utilized, as shown in FIG. 3 of the &#39;162 patent. FIG. 11 of the &#39;375 patent illustrates the anatomical arrangement of a surgically implantable pump with a reciprocating piston-valve. Other patents directed to implantable pumps and or linear pumps include U.S. Pat. Nos. 5,676,651, 5,693,091, 5,722,930, and 5,758,666. 
   Conventional pumps have long been used to pump a slurry consisting of a fluid and a semi-solid material, which is common in sewage wastewater. Conventional wastewater pumps have significant problems due to pump plugging and abrasion, which increases repair and maintenance costs, and results in poor pump efficiency and/or short pump life. 
   The disadvantages of the prior art are either overcome or are reduced by the present invention, and improved linear pumps and methods of pumping fluids are hereinafter disclosed which overcome many of the disadvantages of prior art pumps, including relatively high cost of manufacture and/or poor pump efficiency. 
   The present invention is directed at overcoming, or at least improving upon, the disadvantages of the prior art. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a highly versatile linear pump of a type generally shown and described in U.S. Pat. Nos. 6,352,455 and 6,607,368, the entire contents of which are hereby incorporated into this disclosure as if set forth in their entirety herein. The linear pump of the present invention is similar to the linear pumps of the &#39;455 and &#39;368 patents in that it includes an inner chamber disposed within an outer chamber, each having one or more inlets and outlets for passing fluid into and out of each respective chamber to pump fluid. The present invention is different from (and improved relative to) the linear pump of the &#39;455 and &#39;368 patents in that the outer chamber and inner chamber are both generally rigid, wherein the circumference of the inner chamber may be adjusted via a plurality of generally rigid ribs and linear motors, and the end plates do NOT move relative to one another. The linear pump of the present invention may find use in any number of fluid pumping and/or vehicle propulsion applications, including but not limited to pumping water, air, etc. . . . for any of a variety of marine, medical, industrial, governmental and/or recreational uses. 
   In a preferred embodiment, the outer chamber of the linear motor of the present invention is generally rigid, and includes a plurality of intake ports to permit fluid to enter into the outer chamber (including but not limited to one-way check valves) and a plurality of outlet ports to permit movement of the fluid or relative fluid of the device (including but not limited to one-way check valves). The inner chamber is constructed from a plurality of generally rigid plate members or “slat-like” ribs which run the length of the pumping system of the present invention. Each rib member cooperates with one or more linear motors such that the rib members may be selectively forced in a radial (i.e. outward) direction and medial (i.e. inward) direction. 
   To facilitate this radial and medial motion, each rib member is equipped with an articulating member which engages into a groove formed within an adjacent rib member and forms an articulate joint. Preferably, both the rib members and the articulating members are generally curved such that the inner chamber is generally cylindrical. As the linear motors are operated, the rib members are caused to expand and contract within the generally rigid outer chamber. In a preferred embodiment, the linear motors include permanent magnets, but any of a variety of suitable linear drive mechanisms may be employed without departing from the scope of the present invention, including but not limited to hydraulic and pneumatic. To ensure no pressure loss during operation, the articulating member may be equipped with any of a variety of sealing features, including but not limited to O-rings or the like to prevent the passage of fluid in between the adjacent rib members during contraction and/or expansion. 
   One advantage of this design is that, unlike the linear pump systems shown and described in U.S. Pat. No. 6,352,455 or 6,607,368 (the entire contents of which are hereby incorporated into this disclosure as if set forth fully herein), is that the inner chamber is not a bladder which will stretch and recover. The power is 90-degree opposition, which provides close to a 100% power exchange instead of the 70% with the flexible bladder of the &#39;455 or &#39;638 patents. This is a significant distinction in that it will allow the device of the present invention, when attached to a vehicle of appropriate size and construction, to actually propel the vehicle from a position on top of or under the water to an airborne state out of the water. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Many advantages of the present invention will be apparent to those skilled in the art with a reading of this specification in conjunction with the attached drawings, wherein like reference numerals are applied to like elements and wherein: 
       FIG. 1  is a side view of a linear pump of the present invention; 
       FIG. 2A  is a cross-sectional view of the linear pump of the present invention taken along line  2 - 2  in  FIG. 1 ; 
       FIG. 2B  is a partial cross-sectional view of the linear pump of the present invention taken along line  2 - 2  in  FIG. 1 ; 
       FIG. 3  is an exploded view of the inner chamber of the linear pump of the present invention; 
       FIG. 4  is an exploded view of a rib member forming part of the inner chamber of the linear pump of the present invention; 
       FIG. 5  is a perspective view of a linear pump according to another embodiment of the present invention; 
       FIG. 6  is a side cross-sectional view of the linear pump of the present invention as shown in  FIG. 5  illustrating the simultaneous “inner chamber fluid discharge” and “outer chamber fluid charge” according to the present invention; 
       FIG. 7  is a side cross-sectional view of the linear pump of the present invention as shown in  FIG. 5  illustrating the simultaneous “outer chamber fluid discharge” and “inner chamber fluid charge” according to the present invention; 
       FIG. 8  is a side view of the linear pump of the present invention as shown in  FIG. 5  illustrating the inner chamber in the contracted state; 
       FIG. 9  is a side view of the linear pump of the present invention as shown in  FIG. 5  illustrating the inner chamber in the expanded state; 
       FIG. 10  is a perspective view of a prior art linear pump having a flexible inner chamber, the pump presented in partial cross-section in a condensed bladder configuration, such as after discharging fluid from the inner chamber of the bladder; and 
       FIG. 11  is a Perspective view of the linear pump of  FIG. 10  after modification to include a generally rigid inner chamber of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. The linear pump of the present invention disclosed herein boasts a variety of inventive features and components that warrant patent protection, both individually and in combination. 
   Referring first to  FIG. 10 , there is shown a depiction of a linear pump  50  as shown and described in detail in U.S. Pat. No. 6,607,368. The linear pump  50  includes an inner chamber  52  and an outer chamber  54 . The linear pump  50  also includes end plates  56  having a plurality of intake valves  58  and/or outlet valves  60 . Notably, the linear pump  50  further includes a plurality of flexible rib members  62  such that inner chamber comprises a flexible bladder which will stretch and recover. 
     FIGS. 1-4  and  11  depict a linear pump  10  according to one embodiment of the present invention. The pump  10  is of a type generally shown and described in U.S. Pat. Nos. 6,352,455 and 6,607,368, the entire contents of which are hereby incorporated into this disclosure as if set forth in their entirety herein. The linear pump  10  of the present invention is similar to the linear pumps of the &#39;455 and &#39;368 patents in that it includes an inner chamber  12  disposed within an outer chamber  14 , each having one or more inlets and outlets for passing fluid into and out of each respective chamber to pump fluid. The present invention is different from (and improved relative to) the linear pump of the &#39;455 and &#39;368 patents in that the outer chamber  14  and inner chamber  12  are both generally rigid, wherein the circumference of the inner chamber  12  may be adjusted via a plurality of generally rigid ribs  16  and linear motors  18 , and the end plates  20  do NOT move relative to one another. The linear pump  10  of the present invention may find use in any number of fluid pumping and/or vehicle propulsion applications, including but not limited to pumping water, air, etc. . . . for any of a variety of marine, medical, industrial, governmental and/or recreational uses. 
   In a preferred embodiment, the outer chamber  14  of the linear pump  10  of the present invention is generally rigid, and includes a plurality of intake ports to permit fluid to enter into the outer chamber (including but not limited to one-way check valves) and a plurality of outlet ports to permit movement of the fluid or relative fluid of the device (including but not limited to one-way check valves). The inner chamber  12  is constructed from a plurality of generally rigid plate members or “slat-like” ribs  16  which run the length of the pumping system of the present invention. Each rib member  16  cooperates with one or more linear motors  18  such that the rib members  16  may be selectively forced in a radial (i.e. outward) direction and medial (i.e. inward) direction. 
   To facilitate this radial and medial motion, each rib member  16  is equipped with an articulating member  22  which engages into a groove  24  formed within an adjacent rib member  16  and forms an articulated joint. Preferably, both the rib members  16  and the articulating members  22  are generally curved such that the inner chamber  12  is generally cylindrical. As the linear motors  18  are operated, the rib members  16  are caused to expand and contract within the generally rigid outer chamber  14 . In a preferred embodiment, the linear motors  18  include permanent magnets, but any of a variety of suitable linear drive mechanisms may be employed without departing from the scope of the present invention, including but not limited to hydraulic and pneumatic systems. To ensure no pressure loss during operation, the articulating member may be equipped with any of a variety of sealing features, including but not limited to O-rings or the like to prevent the passage of fluid in between the adjacent rib members  16  during contraction and/or expansion. 
   One advantage of this design is that, unlike the linear pump systems shown and described in U.S. Pat. No. 6,352,455 or 6,607,368 (the entire contents of which are hereby incorporated into this disclosure as if set forth fully herein), the inner chamber  12  is not a bladder which will stretch and recover. The power is 90-degree opposition, which provides close to a 100% power exchange instead of the 70% with the flexible bladder of the &#39;455 or &#39;638 patents. This is a significant distinction in that it will allow the pump  10  of the present invention, when attached to a vehicle of appropriate size and construction, to actually propel the vehicle from a position on top of or under the water to an airborne state out of the water. 
     FIGS. 5-9  illustrate the use of a linear pump  30  according to the present invention, the main difference between the pump  10  of  FIGS. 1-4  being that the outer chamber  14  has inlets and outlets disposed along the outer periphery of the outer chamber  14 . As shown in  FIG. 6 , the linear pump  30  of the present invention (along with the embodiment shown in  FIGS. 1-4 ) is capable of simultaneously discharging the fluid within the inner chamber while fluid is charged or delivered into the outer chamber according to the present invention. The inverse is also true, as shown in  FIG. 7  (and as it is for the embodiment shown in  FIGS. 1-4 ), wherein the linear pump of the present invention is capable of simultaneously discharging the fluid within the outer chamber while fluid is charged or delivered into the inner chamber according to the present invention. 
     FIG. 8  is a side view of the linear pump of the present invention as shown in  FIG. 5  illustrating the inner chamber in the contracted state.  FIG. 9  is a side view of the linear pump of the present invention as shown in  FIG. 5  illustrating the inner chamber in the expanded state. 
   While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined herein and claimed below.