Planar wave transducer assembly
AssigneeBarcus-Berry, Inc.
InventorLester M. Barcus
Life of this patent
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Abstract
A planar wave transducer assembly comprising a rigid structure formed by a pair of foot pads, each with an upstanding leg and a span bar extending across the top of the legs. A piezoelectric transducer element is attached to the span bar, preferably in a channel extending between the legs, to convert wave motion in the plane defined by the flat bases of the foot pads into an electrical signal. The transducer assembly herein disclosed has been found to be remarkably effective as a pick up when applied to the soundboard of a piano, achieving excellent signal isolation as well as enhancing the acoustic sound produced by the instrument.
Claims13
For a musical instrument having a soundboard, a transducer assembly to convert into an electrical signal the wave motion produced in the soundboard during the playing of said instrument, said transducer assembly comprising:
- first and second legs,
- means for bonding said first and second legs to the soundboard in a spaced relationship to one another, such that one of said legs moves on the soundboard relative to the other leg in response to the wave motion produced in said soundboard,
- means for sensing the movement of said one leg relative to the other leg, and
- means for converting the sensed movement into an electrical signal.
A planar wave transducer assembly connected to a planar surface and including:
- a pair of foot pads connected in spaced relationship with one another to the planar surface, such that one of said foot pads moves along said planar surface relative to the other foot pad in response to wave motion produced in said planar surface,
- an upstanding leg integral with each foot pad,
- a span bar integral with the legs above the foot pads, the span bar, legs and foot pads being integral parts of a relatively rigid unitary structure such that the movement of said one foot pad relative to said other foot pad is transmitted through the legs to the span bar,
- an electrical transducer element for converting mechanical force into an electrical signal,
- means attaching the electrical transducer element to the span bar to sense said movement of said one foot pad along said planar surface and to convert such movement to an electrical signal, and
- means to electrically connect the transducer element to an electronic system.
For a vibratile body having a surface that receives vibrations which propagate at the right angle to the surface of said body for producing sound pressure waves in the air and planar waves that generate the vibrations and propagate along the surface of said body in transverse alignment with said vibrations but do not produce pressure waves in the air, a transducer assembly for converting the planar waves into an electrical signal and comprising:
- means connected to said vibratile body and responsive to the planar waves received by the vibratile body and substantially non-responsive to the vibrations which produce sound pressure waves in the air;
- and
- means connected to said responsive means for converting the planar waves into an electrical signal that is representative of said planar waves propagating along the surface of said body.
Dependencies are inferred from the claim text.