Abstract:
The present invention relates to the field of brass wind musical instruments, and more specifically to an improved axial flow valve which resists wear and optimizes air flow.

Description:
FIELD OF INVENTION 
     The present invention relates to the field of brass wind musical instruments, and more specifically to an improved axial flow valve that resists wear and optimizes air flow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded side perspective view of a precision axial flow valve. 
         FIG. 2  is an exploded sectional view of a precision axial flow valve. 
         FIG. 3  is a top perspective view of the interior of the frusto-conical casing of a precision axial flow valve. 
         FIG. 4   a  is a top view of a back plate for a precision axial flow valve. 
         FIG. 4   b  is a bottom view of a back plate for a precision axial flow valve. 
         FIG. 5  is a side view of a back plate for a precision axial flow valve. 
     
    
    
     GLOSSARY 
     As used herein, the term “axial flow valve” is a conically shaped rotor valve which includes valve housing, a rotor component, a back plate and optional components to improve performance (e.g., bearings and sealings). In various embodiments, an axial deflects the air flow through the instrument at an angle between 15 and 30 degrees (e.g., 28 degrees). 
     As used herein, the term “frusto-conical” means a solid or hollow elongated structure having a narrower diameter at one end. 
     As used herein, the term “valve housing” means a machined component adapted to receive a rotor component and back plate, and which may further be adapted to receive optional components such as seals and one or more bearings. 
     As used herein, the term “friction resistant” means having the capability of minimizing friction between the housing, rotor and back plate components of a valve. 
     As used herein, the term “bearing seat” means a specially machined or tooled recess on the inner surface of an axial flow valve housing adapted to receive a bearing, seal or other component. 
     As used herein, the term “bearing” or “friction reducing component” means a component, surface or substance that reduces the friction between two surfaces. For example, a bearing may be a ring which moves in a rotatable manner. 
     As used herein, the term “sealing ring” means any physical component which enhances or limits airflow for optimum valve performance and instrument tone quality. For example, a sealing ring may include, but not be limited to a plastic or rubber ring, an adhesive or moldable substance or a non-circular component to control air flow. 
     As used herein, the term “structural complement” means adapted to receive and/or fit within another component (e.g., a bearing, seal, lock ring or other component of an axial flow valve). 
     BACKGROUND 
     Various rotary axial valves are known in the art. One example is the “Thayer Valve” which is the subject of U.S. Pat. No. 4,469,002, filed in May 1982, issued in September 1984, and is now expired. 
     Rotary axial valves generally include housing and a rotor having at least two apertures extending through the rotor and the housing. At least one of the passages is substantially straight, while the other deflects the flow of air at an angle. 
     The apertures and passages are configured to align axially with the instrument&#39;s lead pipe, main bore, and slide loop ends to allow the user to better control airflow through these components and reduce the effort required to achieve a range of notes and tones. 
     A problem known in the art with traditional axial flow valves is that they are prone to wear because of the continuous friction between the rotor, housing and back plate. 
     Friction between these components will eventually compromise the seal of the valve necessary to direct airflow through the desired passages to achieve optimum tone quality. 
     Friction and the loss of seal within a valve result in costly repairs and replacements and compromised sound quality. 
     SUMMARY OF THE INVENTION 
     The present invention is an improved axial flow valve which is comprised of a contoured housing adapted to receive at least one bearing and which further includes at least one sealing ring that may be placed on the housing, rotor or back plate. Various embodiments of the invention may include a back plate that is also adapted to receive a friction-reducing bearing or friction-reducing contour. 
     DETAILED DESCRIPTION OF INVENTION 
     For the purpose of promoting an understanding of the present invention, references are made in the text to exemplary embodiments of a high precision axial flow valve for musical instruments, only some of which are described herein. It should be understood that no limitations on the scope of the invention are intended by describing these exemplary embodiments. One of ordinary skill in the art will readily appreciate that alternate but functionally equivalent high precision axial flow valves for musical instruments, only some of which are described herein, may be used. The inclusion of additional elements may be deemed readily apparent and obvious to one of ordinary skill in the art. Specific elements disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to employ the present invention. 
     It should be understood that the drawings are not necessarily to scale; instead emphasis has been placed upon illustrating the principles of the invention. In addition, in the embodiments depicted herein, like reference numerals in the various drawings refer to identical or near identical structural elements. 
     Moreover, the terms “substantially” or “approximately” as used herein may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. For example, a high precision axial flow valve for musical instruments may have more or fewer bearings and seals, and the location or position of the bearing and sealing ring on the valve may vary. 
       FIG. 1  is an exploded side perspective view of an exemplary embodiment of a precision axial flow valve  100 , which includes a substantially frusto-conical casing  20  comprised of wide end  22 , threaded neck  24 , narrowed end  26 , and side exit tube  28  positioned at an angle relative to the outer surface of frusto-conical casing  20  and bottom exit tube  29 . Bearing  88  is positioned within frusto-conical casing  20  on bearing seat  89  (not visible). Also shown is sealing ring  86 . 
     The embodiment shown in  FIG. 1  further includes a selectively attachable back plate  30 , two apertures  32 ,  33  for directing airflow, and one bore  35  for inserting shaft  37 . Frusto-conical casing  20  and back plate  30  are rotatably positioned around said shaft  37 . Also visible are back plate bearing  60  and back plate sealing ring  62 . 
     The embodiment shown in  FIG. 1  further includes an inner rotor component  40  having two rotor apertures  42 ,  44  and narrow end  46  adapted to structurally complement bearing  88 .  FIG. 1  also shows lock ring  50  having threaded inner surface  52 . 
       FIG. 2  is an exploded sectional view of  FIG. 1  in which the inner contours of precision axial flow valve  100  are visible. Also visible in  FIG. 2  is sealing ring groove  55  which is structurally adapted to receive sealing ring  62 . Not visible in  FIG. 2  are aperture  33  and rotor aperture  44 . 
       FIG. 3  illustrates a top perspective view of an exemplary embodiment of the interior of frusto-conical casing  20  in which bearing  88  (not shown) has been removed and in which bearing seat  89  is visible. 
     The exemplary embodiment of frusto-conical casing  20  shown in  FIG. 3  further includes machined contour  97 . In the embodiment shown, machined contour  97  includes contoured bore  92  and corresponding protuberance  93  adapted to receive a bearing having a diameter larger than the inner diameter of frusto-conical casing  20  without interfering with airflow when the bearing is positioned within frusto-conical casing  20 . In other embodiments, machined contour  97  may be a uniform recess around the inner circumference of frusto-conical casing  20 ; in such embodiment, contoured bore  92  and corresponding protuberance  93  may be omitted. 
       FIG. 4   a  is a top view of back plate  30  of precision axial flow valve  100  in which bore  35  and apertures  32 ,  33  are visible. 
       FIG. 4   b  is a bottom view of back plate  30  of precision axial flow valve  100  in which back plate bearing  60  is visible. 
       FIG. 5  is a side view of back plate  30  which illustrates sealing ring groove  55  which is a structural contour adapted to receive back plate sealing ring  62  (not shown).