Abstract:
An extruded recording sensor mounting rail for keyboard operated musical instruments, particularly electronic player pianos, which can be used to install recording sensors in a new or existing piano. First and second flanges extend longitudinally along the front and rear of the mounting rail. A shelf is provided on the first flange, with the shelf configured for receiving and supporting one edge of a circuit board in a sensor assembly. The first flange includes a groove adapted to receive a threaded fastener for securing the edge of the circuit board onto the shelf. In the preferred embodiment, the second flange includes an inward facing lip which defines a flute configured for receiving and supporting the other edge of the circuit board. In the alternate embodiment, the second flange includes a shelf and a groove adapted to receive a threaded fastener for securing the other edge of the circuit board onto the shelf.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention pertains generally to recording keystroke information in a keyboard operated musical instrument, and more particularly to a mounting rail assembly for supporting optical recording sensors associated with the keys, hammers, hammer shanks or hammer catchers in a piano. 
     2. Description of the Background Art 
     Recording sensors are commonly used in electronic player piano systems to capture keystroke information. Typically, sensor assemblies are mounted below the keyboard to sense the movement and position of the keys for recording the original piano performance. In conventional player piano systems, the sensor assemblies are mounted on a common rack assembly which is sized to match the size of the keyboard. Since the rack assembly must be sized to match the size of the keyboard, it is necessary to customize the rack assembly for different types of player pianos. 
     Currently available rack assemblies do not provide for adjustability of the position of the sensors in relation to the keys. In the piano industry, however, there are at least four distinct piano key spacing arrangements. It will be appreciated that there is a large number of individual keys to be sensed in a player piano. Further, optical sensors may be positioned for sensing the movement and position of hammers, hammer shanks, or other moving portions of the piano which are associated with the piano keys. Currently used sensor rack assemblies are generally structured and configured to be positioned beneath the piano keys themselves, and are not suitable for supporting optical sensors which detect position and motion of hammers, hammer shanks, or moving parts other than the piano keys themselves. 
     Thus, there is a need for an apparatus which will allow for sensing key movement without interfering with the key movement, which provides for accurate positioning of each sensor in relation to the corresponding key, and which can be used for supporting optical sensors for the detection of position and movement of hammers, hammer shanks, or like moving parts of a piano which are associated with the keys. There is a further need for sensor assemblies which can be easily retrofitted to existing pianos with varying keyboard sizes and key spacing configurations. The present invention satisfies those needs, as well as others, and overcomes the deficiencies found in conventional sensor assembly mounting techniques. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention pertains to a recording sensor mounting rail assembly for keyboard operated musical instruments, particularly electronic player pianos, which can be used to install recording sensors in a new or existing piano and provide for accurate alignment of the sensors in association with the individual keys in the instrument. 
     By way of example, and not of limitation, the invention comprises an elongated mounting rail which is preferably extruded as an integral component. A pair of flanges extend along the front and back edges of the mounting rail, and an open channel is defined between the flanges. Each flange includes a step or shelf that extends along the flange, with a shoulder running along the inner edge of the shelf, and a corner running along the outer edge of the shelf. A plurality of the rails may be joined together end to end in order to provide a sensor assembly which extends along the length of the keyboard of the piano. 
     The flange along the front edge includes an upward facing groove adapted to receive a threaded fastener therein. The step or shelf is configured to receive the front edge of a circuit board placed thereon. In the preferred embodiment, the flange along the back edge includes an inner lip that extends along the length of the back flange defining an elongated flute between the lip and the step or shelf. The flute is configured to receive the back edge of the circuit board placed therebetween. In the alternate embodiment, the back flange also includes an upwards facing groove adapted to receive a threaded fastener therein. The step of shelf is configured to receive the back edge of the circuit board placed thereon. A plurality of threaded fasteners is used to secure the circuit board onto the mounting rail. 
     An object of the invention is to provide a recording sensor mounting rail which permits accurate alignment of the recording sensors in relation to the keys, hammers, hammer shanks, or like moving part associated with the keys in a keyboard operated musical instrument. 
     Another object of the invention is to provide a recording sensor mounting rail which allows multiple rails to be connected to accommodate different sizes of keyboards. 
     Another object of the invention is to provide a recording sensor mounting rail which can be easily retrofitted to existing keyboards. 
     Another object of the invention is to provide a recording sensor mounting rail which provides for stable mounting of recording sensor assemblies. 
     Still another object of the invention is to provide a recording sensor mounting rail which is immutable to vibration which causes misalignment of the circuit board sensors. 
     Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing the invention without placing limits thereon. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more fully understood by reference to the following drawings which are illustrative purposes only: 
     FIG. 1 is a perspective view of one embodiment of a mounting rail assembly supporting a circuit board shown in phantom. 
     FIG. 2 is an exploded view of the assembly shown in FIG.  1 . 
     FIG. 3 is a cross-sectional view of a mounting rail shown in FIG. 1 taken through line  3 — 3  with the circuit board shown in phantom. 
     FIG. 4 is a perspective view of a second embodiment of a mounting rail assembly supporting a circuit board shown in phantom. 
     FIG. 5 is an exploded view of the assembly shown in FIG.  4 . 
     FIG. 6 is a cross-sectional view of a mounting rail shown in FIG. 4 taken through line  6 — 6  with the circuit board shown in phantom. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG.  1  through FIG. 6, wherein like reference numerals denote like parts. It will be appreciated that the apparatus may vary as to configuration and as to details of the parts without departing from the basic concepts as disclosed herein. 
     Referring to FIG.  1  through FIG. 3, one embodiment  10  of a recording sensor mounting rail assembly in accordance with the present invention is generally shown. The invention includes a mounting rail  12  which is preferably extruded from a lightweight material such as aluminum, engineering resin or the like as an elongated member having first and second ends  14 ,  16 , and front and rear sides  18 ,  20 . First and second elongated flanges  22 ,  24  are included on mounting rail  12 , and extend longitudinally between first and second ends  14 ,  16  of mounting rail  12 . Flanges  22 ,  24  project generally upward from a base portion  26  of mounting rail  12 , and an elongated channel  28  is defined between inner walls  30 ,  32  of flanges  22 ,  24  and adjacent base portion  26 . 
     First and second elongated shelves  34 ,  36  are included on first and second flanges  22 ,  24 , respectively, of mounting rail  12 . Shelves  34 ,  36  extend longitudinally between first and second ends  14 ,  16  of mounting rail  12 . Referring more particularly to FIG. 3, first and second shoulders  38 ,  40  are included along the inner edges of shelves  34 ,  36  respectively adjacent inner walls or faces  30 ,  32  of flanges  22 ,  24  respectively. Shoulders  38 ,  40  extend longitudinally along the length of mounting rail  12  between first and second ends  14 ,  16 . First and second corners  42 ,  44  are included on first and second flanges  22 ,  24  adjacent first and second shelves  34 ,  36  respectively on the outward sides thereof. 
     Referring more particularly to FIG. 2, shelves  34 ,  36  are structured and configured to receive and support the edges  46 ,  48  of a circuit board  50  whereon are mounted a plurality of sensors  52 . Sensors  52  may comprise optical photoemitter/detectors such as Kodenshi SG  107  devices, or other types of optical or piezoelectric sensors. Edges  46 ,  48  of circuit board  50  fit adjacent corners  42 ,  44 , and rest on shelves  34 ,  36  respectively. The position or spacing of sensors  52  on circuit board  50  may be varied as required to accommodate the configuration of piano keys, hammers, hammer shanks or the like which are to be sensed by sensors  52 . 
     First elongated flange  22  includes a first groove  54  which extends longitudinally along first elongated flange  22 . First groove  54  is parallel and adjacent to first elongated shelf  34 . First groove  54  has an upward facing opening  56  defined between the upper surfaces  58   a ,  58   b  of first elongated flange  22  and is structured and configured to receive a threaded fastener  60 , such as a Type AB Truss Head Phillips Machine Screw. Threaded fastener  60  is screwed into first groove  54  to hold edge  46  of circuit board  50  against first elongated shelf  34 . As shown in FIG. 3, the thread diameter of threaded fastener  60  is slightly larger than the width of first groove  54 . As a result, threaded fastener  60  will self-tap the material forming the sides of groove  54  and become secured in position. Alternatively, the material can be tapped to accommodate the threads of threaded faster  60 . A plurality of threaded fasteners  60  can be screwed into first groove  54  to fasten edge  46  of circuit board  50 . As seen in FIG. 3, a gap  62  between the upper surfaces  58   a ,  58   b  of first elongated flange  22  and the bottom of the head  64  of threaded fastener  60  allows for better compression of threaded fastener  60  on edge  46  of circuit board  50 . 
     Second elongated flange  24  includes an inner lip  66  which extends longitudinally along second elongated flange  24 . A flute  68  is defined between inner lip  66  and second elongated shelf  36  and also extends longitudinally along second elongated flange  24 . Flute  68  is structured and configured to receive and support edge  48  of circuit board  50  therein. 
     Circuit board  50  is attached to mounting rail  12  by placing edge  48  of circuit board  50  within flute  68  whereby shelf  36  and inner lip  66  would grip and hold edge  48  in place. Edge  46  of circuit board  50  is placed onto shelf  34  of flange  22  generally flush with corner  42  and with the top of circuit board  50  being generally slightly elevated above upper surface  58   a ,  58   b  of first elongated flange  22 . Threaded fastener is screwed into first groove  54  and the bottom of head  64  of threaded fastener  60  compresses edge  46  of circuit board  50  onto shelf  34 , thereby holding circuit board  50  in place. Threaded fastener  60  can be placed at any point along first groove  54 , and a plurality of threaded fasteners  60  can be used as required. 
     Referring to FIG.  4  through FIG. 6, a second embodiment  70  of a recording sensor mounting rail assembly in accordance with the present invention is generally shown, wherein like reference numerals denote like parts. The invention includes a mounting rail  12  which is preferably extruded from a lightweight material such as aluminum, engineering resin or the like as an elongated member having first and second ends  14 , 16 , and front and rear sides  18 ,  20 . First and second elongated flanges  22 ,  24  are included on mounting rail  12 , and extend longitudinally between first and second ends  14 ,  16  of mounting rail  12 . Flanges  22 ,  24  project generally upward from a base portion  26  of mounting rail  12 , and an elongated channel  28  is defined between inner walls  30 ,  32  of flanges  22 ,  24  and adjacent base portion  26 . 
     First and second elongated shelves  34 ,  36  are included on first and second flanges  22 ,  24 , respectively, of mounting rail  12 . Shelves  34 ,  36  extend longitudinally between first and second ends  14 ,  16  of mounting rail  12 . Referring more particularly to FIG. 4, first and second shoulders  38 ,  40  are included along the inner edges of shelves  34 ,  36  respectively adjacent inner walls or faces  30 ,  32  of flanges  22 ,  24  respectively. Shoulders  38 ,  40  extend longitudinally along the length of mounting rail  12  between first and second ends  14 ,  16 . First and second corners  42 ,  44  are included on first and second flanges  22 ,  24  adjacent first and second shelves  34 ,  36  respectively on the outward sides thereof. 
     Referring more particularly to FIG. 5, shelves  34 ,  36  are structured and configured to receive and support the edges  46 ,  48  of circuit board  50  whereon are mounted a plurality of sensors  52 . Edges  46 ,  48  of circuit board  50  fit adjacent corners  42 ,  44 , and rest on shelves  34 ,  36  respectively. 
     First elongated flange  22  includes a first groove  54  which extends longitudinally along first elongated flange  22 . First groove  54  is parallel and adjacent to first elongated shelf  34 . First groove  54  has a first upward facing opening  56  defined between the upper surfaces  58   a ,  58   b  of first elongated flange  22  and is structured and configured to receive a threaded fastener  60 . Threaded fastener  60  is screwed into first groove  54  to hold edge  46  of circuit board  50  against first elongated shelf  34 . A plurality of threaded fasteners  60  can be screwed into first groove  54  to fasten edge  46  of circuit board  50 . As seen in FIG. 6, a gap  62  between the upper surfaces  58   a ,  58   b  of first elongated flange  22  and the bottom of the head  64  of threaded fastener  60  allows for better compression of threaded fastener  60  on edge  46  of circuit board  50  onto first elongated shelf  34 . 
     Second elongated flange  24  includes a second groove  72  which extends longitudinally along second elongated flange  24 . Second groove  72  has a second upward facing opening  74  defined between upper surfaces  76   a ,  76   b  and is structured and configured to receive threaded fastener  60  therein. Threaded fastener  60  is screwed into second groove  72  to hold edge  48  of circuit board  50  against second elongated shelf  36 . A plurality of threaded fasteners  60  can be screwed into second groove  72  to fasten edge  48  of circuit board  50  thereon. Gap  78  between upper surfaces  76   a ,  76   b  of second elongated flange  24  and the bottom of the head  64  of threaded fastener  60  allows for better compression of threaded fastener  60  on edge  48  of circuit board  50 . Circuit board  50  is attached to mounting rail  12  by placing edges  46 ,  48  of circuit board  50  onto shelves  34 ,  36 , of flanges  22 ,  24 , respectively. Edges  46 ,  48  of circuit board  50  are generally flush with corners  42 ,  44 , and the top of edge  46  of circuit board  50  being generally slightly elevated above upper surface  58   a ,  58   b  of first elongated flange  22 , and the top of edge  48  of circuit board  50  being generally slightly elevated above upper surface  76   a ,  76   b  of second elongated flange  24 . Threaded fasteners are screwed into first and second grooves  54 ,  72  and the bottom of heads  64  of threaded fasteners  60  compresses edges  46 ,  48  of circuit board  50  onto shelves  34 ,  36 , respectively, thereby holding circuit board  50  in place. Threaded fasteners can be positioned at any point along first and second groove  54 ,  72 , and a plurality of threaded fasteners can be used as required. 
     Accordingly, it will be seen that both embodiments of the recording sensor mounting rail of the present invention provides for convenient mounting of recording sensor assemblies in association with the keyboard assembly of a keyboard operated musical instrument in a manner which can accommodate different keyboard lengths and varied key spacing. Although the description above includes many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments. Thus, the scope of this invention should be determined by the appended claims and their legal equivalents.