Patent Publication Number: US-2011048561-A1

Title: Zero-pitch pipe

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to the field of pipes for conveying fluids, and more particularly to a type of pipe through which a fluid will flow without the force of gravity, as when a pipe is installed with no downward pitch. 
     The present invention comprises a pipe through which a fluid can move without backflow in the absence of a gravity force provided by a downward pitch. This is accomplished by providing within the pipe a series of one-way valves each having a structure similar to a mitral valve, with a rigid upper flap cooperating with a semi-rigid but flexible lower flap. Fluid pressure upstream of the valve will displace the lower flap enough to allow fluid to accumulate in a reservoir area downstream of the valve and upstream of a ramp structure. When sufficient fluid accumulates in the reservoir area, it overflows the ramp structure and proceeds to the next one-way valve, and the process is repeated. 
     U.S. Pat. No. 4,989,760 to Songzeng, describes a self-filling siphon pipe which comprises a series of internal one-way valves. But the Songzeng device relies on the suction force from a siphon hose to move liquid through the pipe, whereas the present invention requires no fluid transport force beyond the passive fluid pressure in the pipe. 
     U.S. Pat. No. 3,855,995 to Bentley describes a blood pumping assembly in which a series of leaflet-type valves are used in conjunction with a ramp-like structure to provide passive flow of blood through the device. But the valve structure is dissimilar to the present invention insofar as it lacks the asymmetrical flexibility of the valve. Also, fluid movement through the assembly is ultimately dependent on the external force provided by a pump. 
     U.S. Pat. No. 6,089,260 to Jaworski et al. describes nested duckbill check valve system for back-flow prevention used in conduits such as garden hose nozzles. While this design has serial one-way check valves, it provides no mechanism for passive fluid flow and thus would not be applicable to a zero-pitch pipe. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a tubular pipe fabricated of durable metal or plastic. Within the pipe are a series of one-way valves, with each valve comprising a rigid upper flap and a semi-rigid, flexible lower flap. The upper flap is preferably concave and the lower flap is preferably flat. The upper flap is rigidly attached to the upper interior surface of the pipe, while the lower flap is rigidly attached to the lower interior surface of the pipe. 
     Downstream of each one-way valve is a ramp structure that has a forward slope and a rear slope. The forward slope is less steeply inclined than the rear slope. The ramp structure is fabricated of rigid metal or plastic and is rigidly attached to the lower interior surface of the pipe. 
     When a fluid flow within the pipe encounters one of the one-way valves, the pressure of the fluid causes the valve&#39;s lower flap to bend downward, thus allowing the fluid to fill the back reservoir until it overflows the rear slope of the ramp structure and flows down the forward slope into the front reservoir. 
     The fluid accumulates in the front reservoir until the fluid pressure causes the lower flap of the next one-way valve to bend downward, and the flow process described above is repeated. In this way, a fluid can flow from one end of the pipe to the other without the aid of gravity. 
     Optionally, the one-way valves can be eliminated, such that the fluid flow through the pipe is controlled by the ramp structures alone. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a longitudinal cross-section view of the preferred embodiment of the present invention. 
         FIG. 2  is a transverse cross-section view of the preferred embodiment of the present invention along the line  2 - 2  shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 and 2 , the present invention  10  comprises a tubular pipe  11  fabricated of durable metal or plastic. Within the pipe  11  are a series of one-way valves  12 , with each valve comprising a rigid upper flap  13  and a semi-rigid, flexible lower flap  14 . The upper flap  13  is preferably concave and the lower flap  14  is preferably flat. The upper flap  13  is rigidly attached to the upper interior surface of the pipe  11 , while the lower flap  14  is rigidly attached to the lower interior surface of the pipe  11 . 
     Downstream of each one-way valve  12  is a ramp structure  15  that has a forward slope  16  and a rear slope  17 . The forward slope  16  is less steeply inclined than the rear slope  17 . The ramp structure  15  is fabricated of rigid metal or plastic and is rigidly attached to the lower interior surface of the pipe  11 . 
     When a fluid flow  18  within the pipe  11  encounters one of the one-way valves  12 , the pressure of the fluid  18  causes the valve&#39;s lower flap  14  to bend downward, thus allowing the fluid  18  to fill the back reservoir  19  until it overflows the rear slope  17  of the ramp structure  15  and flows down the forward slope  16  into the front reservoir  20 . 
     The fluid  18  accumulates in the front reservoir  20  until the fluid pressure  18  causes the lower flap  14  of the next one-way valve  12  to bend downward, and the flow process described above is repeated. In this way, a fluid can flow from one end of the pipe  11  to the other without the aid of gravity. 
     Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that many additions, modifications and substitutions are possible, without departing from the scope and spirit of the present invention.