4'•, 3" 6" However, the reeds are so shaped and tapered that they are still equally spaced at the tip ends where they are engaged by the pins. This allows the substitution of the present vibration plate for a conventional vibration plate, thus improving the high-frequency range, tonal quality, and scale balance, without redesign of the playing mechanism.--DWM

short portion of the air column by terminating the air column at end wall 13 of hollow cylindrical extension tube 15, which mates with the air column tube in a slidable manner.--DWM

4,674,390

43.75.Hi KETTLEDRUM

Barbara A. Allen and Rebecca Kite, Bloomington, IN 23 June 1987 (Class 84/419); filed 1 November 1984

This patent describes an additional feature for the kettledrum pre- viously reviewed [ J. Acoust. Soc. Am. 81, 2006 (1987) ]. It is a foot pedal of special design for changing the tension in the drumhead. "The pedal in- cludes an engaging tooth, and is swivelable to engage and disengage the tooth with complementary teeth to lock the pedal selectively in position. The pedal tooth thereby permits the user to adj•dst and fix the tension on the drumhead."•DWM

4,674,386

43.75.Mn AUGMENTED BASS HAMMER STRIKING DISTANCE FOR PIANOS

Harold A. Conklin, Jr., assignor to Baldwin Piano & Organ Company 23 June 1987 (Class 84/216}; filed 21 June 1985

In conventional pianos, the hammers strike the strings at points vary- ing typically from « of the speaking string length, at the bass end of the scale, to as small as •0 of the speaking length at the treble end. This patent "is based upon the discovery that the tone quality of the bass portion of the scale of some pianos can be improved by increasing the value ofd/L of at least some of the notes to a value greater than «. The findings are that values of d/L between « and • produce the best results. It also has been determined that the optimum value ofd/L depends upon the frequency of the particular note in

4,679,479

43.75.Hi ELECTRONIC DRUM

Hisakazu Koyamato, assignor to Nippon Gakki 14 July 1987 (Class 84/1.04); filed in Japan 1 May 1985

In this electronic, nonacoustical drum, which provides control signals to an electronic drum generator, there is a foamed layer inserted as an impact absorbing layer between the relatively hard surface layer impacted by the drum sticks, and the relatively hard base layer on which a transducer is mounted, in order to detect the striking action at the surface layer. The purposes are to provide the drummer with a tactile response from the drum stick similar to that for an acoustical drum, and to provide an electronic drum that produces little radiated noise when struck.--DWM

L•-_O 158 -15 !

-20

-25 6

-3o 9

-45 -50

-5• 9 8 _

-651 -7o I I I I I I I I I I I I I o8 o9 ,o ,, ,2 ,3 ,, ,• ,6 ,? ,8 ,• •o •,

4,676,135

43.75.Kk VIBRATION PLATE FOR MUSlc BOX MOVEMENT

Yasuhide Kitazawa, Mikio Shibagaki, and Motonori Usui, assignors to Kabushiki Kaisha Sankyo Seiki Seisakusho

30 June 1987 (Class 84/94 R); •ed in Japan 12 March 1985

A conventional vibration plate for a music box supports tuned-reed vibrators of uniform width, the tapered ends of which are engaged by pins projecting from a rotating drum, with the pins so arranged to produce the desired melody or chords. In this patent, the width of reeds 51 is scaled from maximum width at the bass end 4 to minimum width at the treble end 6.

question and also upon the design parameters of each particular string." Numerous graphs are included to show the effect of the striking point upon the tone spectrum of the string, and showing the basis for choice of the optimum value in specific cases. Although judgment of piano tone quality is subjective, the graphs shown clearly illustrate the factors leading to an opti- mum choice of strike point.--DWM

4,677,889

43.75.Tv HARMONIC INTERPOLATION FOR PRODUCING TIME VARIANT TONES IN AN ELECTRONIC MUSICAL INSTRUMENT

Ralph Deutsch, assignor to Kawai Musical Instrument Manufacturing Company

7 July 1987 (Class 84/1.01); filed 25 October 1985

This digital electronic musical instrument is of the type in which musi- cal tonewaves are generated by computing successive ordinate values from a sequence of harmonic coefficient values. In order to provide a time varying tone spectrum, different sets of harmonic coefficient values are stored in memory, and the sequence of ordinate values is computed in response to a timing clock by gradual interpolation between one set and another set of stored harmonic coefficients.--DWM

2169 J. Acaust. Sac. Am. 82(6), Dec. 1987; 0001-4966/87/122169-01500.80; ¸ 1987 Acaust. Sac. Am.; Patent Reviews 2169

Redistribution subject to ASA license or copyright; see http://acousticalsociety.org/content/terms. Download to IP: 129.24.51.181 On: Fri, 28 Nov 2014 20:03:04