Structure of rotary valve assembly used in wind instrument

Abstract: A rotary valve assembly incorporated in a brass instrument for changing a pitch of a tone comprises a rotary valve (101) housed in a valve casing having two groups of aeroports, and the rotary valve is provided with two air passages (105 and 106) one of which interconnects the aeroports in the first group and the other of which interconnects the aeroport of the first group and the aeroport of the second group, so that various arrangement is possible for the aeroports.

Description: This invention relates to a rotary valve assembly incorporated in a wind instrument as mentioned in the introduction part of claim 1. DESCRIPTION OF THE RELATED ART The brass instrument such as a trumpet, a horn a trombone or a tuba largely comprises a mouthpiece, a tube member coupled to the mouthpiece and having an air conduit for providing a column of air, and a plurality of valve members respectively associated with keys and provided in the tube member. Each of the valve members is provided with a single or some air passages selectively coupled to the air conduit depending upon the associated key motion and, accordingly, changes the pitch of vibration of the column of air, thereby allowing the different tone to be produced. One of the prior art valve assembly incorporated in the brass instrument is povided with a rotary valve 1 housed in a valve casing (not shown), and the rotary valve 1 is generally shaped into a column configuration as shown in Figs. 1 and 2. The rotary valve has two lug portions 2 and 3 rotatablly supported by the valve casing and is constricted in the middle to form two air passages 4 and 5. Though not shown in the drawings, the valve casing has aeroports selectively coupled through the air passages 4 and 5. Namely, when the player depresses the associated key, the rotary valve 1 is driven for rotation around the center axis 6, and, accordingly, the aeroports are selectively coupled through the air passages 4 and 5 or blocked by the rotary valve 1. Since the aeroports are coupled to the air conduit formed in the tube member, the column of air is changed in volume for varying the pitch of the tone. Since the air passages 4 and 5 are formed in the central portion of the rotary valve 1 in such a manner as to be the back to back arrangement, the aeroports should be formed around the center axis 6, and the respective center axes thereof be arranged on a virtual plane 7 which is substantially perpendicular to the center axis 6. Turning to Fig. 3 of the drawings, there is shown another rotary valve 11. The rotary valve 11 is constricted twice to provide two pairs of air passages 12, 13, 14 and 15 and has two lug portions 16 and 17. The lug portions 16 and 17 are rotatablly supported by a valve casing (not shown), and the two pairs of the air passages 12 to 15 simultaneously couple aeroports formed in the valve casing. Each pair of the air passases are also arranged in the back to back arrangement, so that the aeroports should be disposed in the juxtaposition and the two groups of the center axes be arranged on virtual planes 18 and 19, respectively, which are substantially perpendicular to a center axis 20 of the rotary valve 11. Still another prior art rotary valve 21 is illustrated in Figs. 4 and 5 and generally shaped into a column configuration. The rotary valve 21 is characterized by a curved air passage 22 which is open at both ends thereof to the circumferential surface of the rotary valve 21. The rotary valve 21 is associated with two lug portions 23 and 24 supported by a valve casing (not shown), and aeroports formed in the valve casing are selectively coupled through the curved air passage 22 or blocked by the rotary valve 21 depending upon the angular position of the rotary valve 21. The center line of the air passage 22 is on a virtual plane 25, and, accordingly, the center axes of the aeroports be radially arranged on the virtual plane 25. Fig. 6 shows still another prior art rotary valve 31 which is provided with two air passages 32 and 33. Both of the air passages 32 and 33 are open to the circumferential surface of the rotary valve 31 but different in angular position from one another. The centers of the air passages 32 and 33 are respectively located on virtual planes 34 and 35, so that the aeroports are grouped into two, and all aeroports in each group be arranged in such a manner that the center axes thereof be radially disposed on the virtual plane 34 or 35. Turning to Figs. 7 and 8, still another rotary valve 41 has a generally column configuration accompanied with a lug portion 42 projecting from the bottom surface of the column shaped rotary valve 41. An air passage 43 is opened at one end thereof into the top surface of the rotary valve 41 and at the other end thereof into the circumferential surface of the rotary valve 41 and, accordingly, curved at right angle. By virtue of this arrangement, aeroports formed in a valve casing (not shown) can be disposed in such a manner that the center axes thereof are on respective planes substantially perpendicular to each other. In the valve casing the rotary valve 41 is paired with another rotary valve of the same type and steers an air flow in cooperation with the rotary valve paired therewith. A rotary valve incorporated in still another rotary valve assembly is illustrated in Figs. 9 and 10. The rotary valve 51 shown in Figs. 9 and 10 has a generally column shaped configuration, and two lug portions 52 and 53 project from the top and bottom surfaces of the column shaped rotary valve 51. The rotary valve 51 is partially cut away to form two air passages 54 and 55, and the two air passages 54 and 55 are opened into the circumferential surface of the rotary valve 51 in the back to back fashion. Though not shown in the drawings, aeroports formed in a valve casing (not shown) have respective center axes provided on a virtual plane 56 in correspondence with the air passages 54 and 55. Turning to Figs. 11 and 12, still another rotary valve 61 is shaped into a generally frusto-conical configuration and has a lug portion 65 projecting from the bottom surface of the generally frusto-conical rotary valve 61. In this prior art example, two air passages 62 and 63 are formed in the rotary valve 61, and the air passage 63 is opened at one end thereof to the bottom surface of the rotary valve and at the other end thereof to the circumferential surface of the rotary valve 61. On the other hand, the air passage 62 has openings one of which is open to the bottom surface and the other of which is open to the top surface. Each of the air passages 62 and 63 is coupled to an aeroport open to the bottom surface, however, other aeroports are open to either top or circumferential surface. The other aeroports should be arranged in such a manner as to allow the center axes thereof to be on a virtual plane 64. However, a problem is encountered in the rotary valve assemblies shown in Figs. 1 to 6, 9 and 10 in arrangement of the aeroports. Namely, each of the air passags merely interconnects the aeroports with the center axes extending on the virtual plane, and, for this reason, any deviation from the virtual plane is not allowed to the aeroports. This results in that the air passages sets limitations to the arrangement of the aeroports. Moreover, another problem is encountered in the rotary valve assemblies respectively shown in Figs. 7 and 8 and Figs. 11 and 12 in complexity in structure. Namely, since the rotary valves are of the cantilever type, the bearing mechanism of the valve casing is complicate, and, accordingly, the assemblage of the rotary valve requires a time-consuming and elaborate labor. Further internal air passages with an axis extending obliquely to a virtual plane which is perpendicular to the center axis of rotation of the valve is already known from FR-A-335 269. This known rotary valve is driven for rotation over 90 degress. Therefore two obliquely extending internal air passages are necessary interconnecting opposite two virtual planes different at 180 degrees. The rotary valve does not allow coupling of a plurality of air ports in different planes using at least only one obliquely extending internal air passage and which may be extending straightly or curved. SUMMARY OF THE INVENTION It is therefore an important object of the present invention to provide a rotary valve assembly which couples aerosports deviated from each other with at least one obliquely extending air passage which may be extending straightly or curved and whereby the rotary valve assembly is easy for assemblage. In accordance with the present invention, the aforesaid object is obtained with the features of the characterizing parts of claim 1. Preferred embodiments of the invention are mentioned in the dependent subclaims. BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of a rotary valve assembly according to the present invention will be more clearly understood from the following description taken in conjunction with the accompanying drawings in which: Fig. 1 is a front view showing the rotary valve forming part of a prior art rotary valve assembly; Fig. 2 is a side view showing the rotary valve in the direction indicated by arrows A in Fig. 1; Fig. 3 is a front view showing the rotary valve forming part of another prior art rotary valve assembly; Fig. 4 is a front view showing the rotary valve incorporated in still another prior art rotary valve assembly; Fig. 5 is a side view showing the rotary valve in the direction indicated by arrows B in Fig. 4; Fig. 6 is a front view showing the structure of the rotary valve incorporated in still another rotary valve assembly; Fig. 7 is a front view showing the structure of the rotary valve incorporated in still another rotary valve assembly; Fig. 8 is a side view showing the rotary valve in the direction indicated by arrows C in Fig. 7; Fig. 9 is a front view showing the structure of still another prior art rotary valve; Fig. 10 is a side view showing the rotary valve in the direction indicated by arrows D in Fig. 9; Fig. 11 is a front view showing the structure of the rotary valve forming part of still another prior art rotary valve assembly; Fig. 12 is a side view showing the rotary valve in the direction indicated by arrows E in Fig. 11; Fig. 13 is a plan view showing the structure of a rotary valve incorporated in a rotary valve assembly embodying the present invention; Fig. 14 is a view showing the rotary valve in the direction indicated by arrows F in Fig. 13; Fig. 15 is a cross sectional view taken along the line G and showing the rotary valve in the direction indicated by arrows H in Fig. 13; Fig. 16 is a plan view showing the structure of a rotary valve assembly in which the rotary valve shown in Fig. 13 is incorporated. Fig. 17 is a cross sectional view taken along the virtual plane 80 and showing the rotary valve assembly in the direction indicated by arrows I in Fig. 16; Fig. 18 is a plan view showing the rotary valve assembly illustrated in Fig. 16; Fig. 19 is a cross sectional view taken along the virtual plane 80 of fig. 18 and showing the rotary valve assembly in the direction indicated by arrows J where the rotary valve is different in angular position from that shown in Fig. 17; Figs. 20A and 20B are views showing, in modeled form, French horns incorporated with the rotary valve assembly illustrated in Figs. 13 to 19; Fig. 21 is a plan view showing the structure of a rotary valve incorporated in another rotary valve assembly embodying the present invention; Fig. 22 is a front view showing the structure of the rotary valve shown in Fig. 21; Fig. 23 is a cross sectional view taken along the virtual plane 107 and showing the structure in the direction indicated by arrows K in Fig. 21; Fig. 24 is a plan view showing the rotary valve assembly incorporated with the rotary valve illustrated in Fig. 21; Fig. 25 is a cross sectional view taken along the virtual plane 107 and showing the structure in the direction indicated by arrows L; Fig. 26 is a plan view showing the rotary valve assembly shown in Fig. 24; Fig. 27 is a cross sectional view taken along the virtual plane 107 and showing the structure in a different angular position in the direction indicated by arrows M in Fig. 26; and Figs. 28A and 28B are views showing, in a modeled form, French horns in which the rotary valve assembly shown in Fig, 24 is incorporated. DESCRIPTION OF THE PREFERRED EMBODIMENTS First embodiment Referring first Figs. 13 to 15, a rotary valve 71 largely comprises a rotor 72 with a generally column shaped configuration and two lug portions 73 and 74 projecting from both side surfaces of the rotor 72. The lug portions 73 and 74 have respective rotational axes which are aligned with the center axis of the rotor 72, thereby providing a center axis 75 of the rotary valve 71. The rotary valve 71 is associated with a driving mechanism DM coupled to a key member K, and the driving mechanism DM transmits the key motion to the rotary valve 72 for a rotation upon a depression of the key K. The driving mechanism DM is by way of example formed by linkages coupled between the key member K and the rotary valve 71. Turning to Figs. 16 and 17 of the drawings, there is shown a valve casing 76 which largely comprises a bulge portion 77, and two supporting plate members 78 and 79 attached to both sides of the bulge portion 77. The rotary valve 71 and the valve casing 76 as a whole constitute a rotary valve assembly. The rotor 72 is housed in the bulge portion 77, and the two lug portions 73 and 74 are journaled at the supporting plate members 78 and 79, respectively. Assuming now that two virtual planes 80 and 81 are provided for the rotary valve assembly and substantially perpendicular to the center axis 75 of the rotary valve 71, two groups of aeroports 82, 83, 84, 85, 86 and 87 are formed in the bulge portion 77, and each of the aeroport groups is provided on the virtual planes 80 and 81, respectively. Namely, the first group of the aeroports 82, 83 and 84 have respective center axes angularly spaced apart from one another by about 120 degrees on the virtual plane 80. Similarly, three center axes of the aeroports 85, 86 and 87 are angularly spaced apart by about 120 degrees on the virtual plane 81. Turning back to Figs. 13 to 15, three air passages 88, 89 and 90 are formed in the rotor 72, and the two air passages 88 and 90 have respective center axes rotatable on the virtual planes 80 and 81, respectively, however, a center axis of the third air passage 89 extends across the virtual planes 80 and 81. In detail, the first air passage 88 has two openings 88a and 88b the centers of which are provided on the virtual plane 80, and the second air passage 90 is terminated at both openings 90a and 90b the center of which are provided on the virtual plane 81. However, the third air passage 89 has two openings 89a and 89b having respective centers on the virtual planes 80 and 81. If the air passages 88 to 90 are projected onto the virtual plane 80, the air passages are intersected at about 60 degrees as will be understood from Fig. 15. The air passages 88 to 90 are The aeroports 82 to 87 and the air passages 88 to 90 thus arranges are selectively coupled to one another for establishing air conduits. When the rotary valve 71 is maintained in a first angular position, the air passage 88 interconnects the aeroports 83 and 84, and the air passage 89 couples the aeroport 82 with the aeroport 87. In the first angular position, the air passage 90 connects the aeroport 85 to the aeroport 86. However, if the rotary valve 71 turns over about 120 degrees to be shifted into a second angular position, the air passage 88 couples the aeroport 82 to the aeroport 84, and, on the other hand, the air passage 89 interconnects the aeroports 83 and 85. Moreover, the air passage 90 couples the aeroport 86 to the aeroport 87 as shown in Figs. 18 and 19. The rotary valve assembly thus arranged is incorporated in a rotary trumpet, an air flow produced by the player's breath is guided by the air passages 88 to 90 depending upon the angular position of the rotary valve 71. For example, when the rotary valve 71 is shifted to the first angular position, the air flows from the mouthpiece through the aeroport 82, the air passage 89, the aeroport 87, the aeroport 86 and the air passage 90 to the aeroport 85. However, if the rotary valve 71 turns into the second angular position, the air flows from the aeroport 82 through the air passage 88, the aeroport 84, the aeroport 83 and the air passage 89 into the aeroport 85. The rotary valve assembly illustrated in Figs. 13 to 19 is applicable to another brass instrument such as, for example, a French horn. Fig. 20A shows a B b French horn, and Fig. 20B shows an F French horn, both French horns provide respective air conduits passing through three rotary valve assemblies B1 to B3 and F1 to F3. Second embodiment Turning to Fig. 21 to 23, another rotary valve 101 embodying the present invention is illustrated and comprises a rotor 102, and two lug portions 103 and 104, and two air passages 105 and 106 are formed in the rotor 102. One of the air passages 105 and 106 has a center axis extending on a virtual plane 107 substantially perpendicular to a rotational axis 108 of the rotary valve 102, and two openings thereof 109 and 110 are opened to the circumferential plane of the rotor 102. However, the other air passage 106 obliquely extends with respect to the rotational axis 108, and one of the openings of the air passage 106 intersects the virtual plane 107. However, the other opening of the air passage 106 is offset from the virtual plane 107. The rotary valve 101 is housed in the valve casing 113 which is illustrated in Figs. 24 and 25. The valve casing 113 largely comprises a bulge portion 114 and two supporting plate members 115 and 116, and three aeroports 117, 118 and 119 are provided on the bulge portion 114. The rotor 102 is inserted into the bulge portion 114, and the lug portions 103 and 104 are supported by the supporting plate members 115 and 116, respectively, in a rotatable manner. The aeroports 117 and 118 pass through the bulge portion 114 and have respective center axes extending on the virtual plane 107, however, the other air port 119 is spaced apart from the virtual plane 107 by a distance approximately equal to that between the openings 109 and 112. As will be better understood from Fig. 25, when the aeroports are projected onto the virtual plane 107, the aeroports are angularly spaced apart from one another by about 120 degrees. The rotary valve assembly thus arranged provides an air conduit from the aeroport 117 through the air passage 106 to the aeroport 119 in a first angular position. In this first angular position, the air produced by the player's breath flows from the aeroport 117 through the air passage 106 to the aeroport 119. However, if the rotary valve is driven for rotation and shifted into a second angular position, the aeroport 117 is coupled through the air passage 105 to the aeroport 118 as shown in Figs. 26 and 27. In the second angular position, the air is guided by the air passage 105 to the air port 118, so that the rotary valve assembly is operative to change the route for the air depending upon the angular position. If the aeroport 118 is coupled to a bypass tube, the column of air is varied to change the pitch of the tone produced. Figs. 28A and 28B show French horns one of which is of the B b tube and the other of which is of the F tube. Each of the French horns is provided with three rotary valve assemblies for changing the pitch of the tone produced by the player's breath. Although particular embodiment of the present invention have been shown and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention as defined by the appended claims. For example, the air passage 89 of the first embodiment straightly extends in the rotor 72, however, the air passage may be curved in the rotor to avoid undesirable intersection between the air passages. In another implementation, the rotor is formed by a tube member with a plurality aeroports, and internal tubes couple the aeroports for providing the air passages. In this instance, the rotary valve assembly is reduced in weight, and, accordingly, the player easily holds the brass instrument.

Claims: A rotary valve assembly (71, 76; 101, 113) incorporated in a wind instrument particularly in a brass instrument for changing the pitch of a tone produced by a player's breath, comprising: a) a valve casing (76; 113) having a hollow space and provided with a plurality of aeroports (82-87; 117-119); and b) a rotary valve (71; 101) rotationally housed in said hollow space and having a plurality of air passages (88-90; 105, 106), wherein an axis of at least one (89; 106) of said air passages obliquely extends with respect to a first virtual plane (80, 81; 107) substantially perpendicular to a rotational axis (75; 108) of said rotary valve, an axis of but another air passage (88, 105) extends along said virtual plane (80, 81; 107), at least two (82, 84; 117, 118) of said aeroports have respective openings exposed to said hollow space and intersecting said virtual plane at different positions the respective center axis thereof angularly spaced apart from one another, at least one of another aeroport (85-87; 119) being exposed to the hollow space in an offset manner with respect to said virtual plane (80, 81; 107), aforesaid one (89; 106) of said air passages coupling aforesaid another aeroport (87; 119) to one (82; 117) of aforesaid two aeroports at a first angular position, aforesaid another air passage (88; 105) coupling aforesaid two (82; 84; 117, 118) of said aeroports at a second angular position angularly spaced apart from said first angular position, characterized by the respective axis of said aeroports (82, 84; 117, 118) being angularly spaced apart by about 120 degrees and by said first and second angular coupling positions being spaced apart from one another by about 120 degrees. A rotary valve assembly (71, 76) according to claim 1, including a second virtual plane (81) substantially perpendicular to the center axis (75) of said rotary valve (71), said aerosports (82-84; 85-87) containing two aeroport groups the axes of the aeroports of each of said aeroport groups are provided on the two virtual planes (80, 81), respectively, three air passages (88, 89, 90) wherein two (88, 90) of said air passages having respective center axes rotatable on said two virtual planes (80, 81), respectively, the center axis of said third air passage (89) extending across said two virtual planes (80, 81), each of said air passages (88, 89, 90) having two openings, the centers of the two openings of one (88) of said two air passages (88, 90) and the center of one of the two openings of said third air passage (89) are provided on one (80) of said virtual planes and the centers of the two openings of the other (90) of said two air passages (88, 90) and the center of the other opening of said third air passage (89) are provided on said other virtual plane (81). A rotary valve assembly (101, 103) according to claim 1, including three aeroports (17-19) and two air passages (105, 106), the center axis of one (105) of said air passages extending on said virtual plane (107), the other air passage (106) obliquely extending to said rotational axis (108), one of the openings of said obliquely extending air passage (106) intersects the virtual plane (107) and the other opening of said obliquely extending air passage (106) is offset from said virtual plane (107), the center axes of two (117, 118) of said three aeroports extending in the virtual plane (107) and the center axis of said third aeroport (119) is spaced apart from said virtual plane (107) by a distance approximately equal to that between the openings of said obliquely extending air passage (106). A rotary valve assembly (71, 76; 101, 113) according to claim 1, 2 or 3, wherein aforesaid one obliquely extending air passage (89; 106) extending straightly or curved in said rotory valve (71; 101). A rotary valve assembly (71; 76; 101, 113) according to one of the above-mentioned claims 1 to 4, wherein the rotor of the rotary valve (71; 101) is formed by a tube member with said plurality of aeroports, and internal tubes coupling said aeroports for providing said air passages.

Inventors: HAMANAGA SHINJI, HAMANAGA, SHINJI
Applicants: YAMAHA CORP, YAMAHA CORPORATION
Application year: 1989
Main classification: G10D9
IPC codes: G10D9