# US 5,345,037 A · Acoustic drum transmitter and a holder therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,345,037 A - Document ID: US5345037A - Status: Granted - Kind: A - Application number: 08/058,038 - Filed: 1993-05-03 - Granted: 1994-09-06 - Earliest claimed: 1991-11-15 - Assignees: Clavia Digital Musical Instruments AB - Inventors: Hans Nordelius - Web page: https://patentgrep.com/patent/US5345037A ## CPC - G10H 3/146: {using a membrane, e.g. a drum; Pick-up means for vibrating surfaces, e.g. housing of an instrument} - G10H 2230/275: Spint drum - G10H: ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE ## Abstract A transmitter (2) is arranged on an acoustic drum to transform wave motions generated by hits on the drumhead (10) in electrical signals. The transmitter (2) comprises a vibration sensitive body (8) designed to be elastically forced against the drumhead (10). According to a first aspect on the invention the vibration sensitive body (8) has got an oblong shape (L:W) for detection of wave motions of a predetermined direction and within a predetermined frequency range. Another aspect on the invention is to avoid the risk of mechanical damages to the vibration sensitive body (8) as well as to emphasize the ability to detect the wave motions in the drumhead (10). This is implemented by a holder (3) being fixable to the edge (5) of the drum rim (6). The holder (3) includes an elastic spring device (12, 13) carrying the vibration sensitive body (8). Within the L-shaped holder (3) there are conductors (15) electrically connecting the vibration sensitive body (8) with a connector (16 ) incorporated with the holder (3). ## Claims ### Claim 1 A transmitter for obtaining an electrical signal from an acoustic drum, said transmitter comprising a vibration sensitive device resting on the drumhead of said acoustic drum from which wave motions are to be detected, wherein said vibration sensitive device has a substantially oblong shape and wherein the longitudinal axis of said vibration sensitive device is aligned to be generally perpendicular to a wavefront of said wave motions originating from a particular direction on said drumhead. ### Claim 2 (depends on 1) A transmitter according to claim 1, wherein said vibration sensitive device is a bending sensor flexibly and resiliently positioned directly in contact with said drumhead. ### Claim 3 (depends on 1) A transmitter according to claim 1, where said vibration sensitive device is designed to detect waves within a predetermined wavelength range. ### Claim 4 (depends on 1) A transmitter according to claim 1, where said substantially oblong shape of said vibration sensitive device has a width-length ratio of at least 1:2. ### Claim 5 (depends on 1) A transmitter according to claim 1, wherein said oblong shape of said vibration sensitive device is tapered having a point directed towards said wavefront. ### Claim 6 (depends on 1) A transmitter according to claim 1, wherein said vibration sensitive device is positioned on said drumhead such that the wave motions impinging on said vibration sensitive device from said particular direction on said drum cause a higher amplitude signal to be induced in said vibration sensitive device than do wave motions impinging on said vibration sensitive device from other directions. ### Claim 7 (depends on 1) A transmitter according to claim 1, wherein said vibration sensitive device is manufactured of piezo electric ceramic material. ### Claim 8 (depends on 1) A transmitter according to claim 1, wherein said vibration sensitive device is manufactured of piezo electric plastic material. ### Claim 9 (depends on 1) A transmitter according to claim 1, wherein said vibration sensitive device is arranged on said acoustic drum by holding means comprising: a spring device attached to said vibration sensitive device for positioning said vibration sensitive device flexibly and resiliently on said drumhead; electrical conductor means coupled to said vibration sensitive device for transmitting an electrical signal from said vibration sensitive device; connector means coupled to said electrical conductor means to allow transmission of said electrical signal from said transmitter; and fastening means for fastening said holding means to the rim of said acoustic drum. ### Claim 10 (depends on 9) A transmitter according to claim 9, wherein said spring device includes a spacer and a pad of a softer material than the material of said spacer such that said vibration sensitive device is attached to the surface of said pad. ### Claim 11 (depends on 10) A transmitter according to claim 10, wherein said pad is made of a plastic foam. ### Claim 12 (depends on 9) A transmitter according to claim 9, wherein said holding means has a substantially L-shape such that a top leg of said holding means form a cover protruding above said drumhead in a plane substantially parallel to said drumhead, and a bottom leg of said holding means is arranged adjacent to said rim of said acoustic drum and attached thereto by said fastening means. ### Claim 13 (depends on 12) A transmitter according to claim 12, wherein said spring device is arranged on the surface of said cover facing said drumhead. ### Claim 14 (depends on 12) A transmitter according to claim 12, wherein said top leg and said bottom leg form a hook having a shape formed to correspond to the shape of the edge of said rim of said acoustic drum. ### Claim 15 (depends on 12) A transmitter according to claim 12, wherein said electrical conductor means and said connector means are positioned within said holding means, said connector means positioned within said bottom leg of said holding means. ### Claim 16 A transmitter for obtaining an electrical signal from an acoustic drum, said transmitter comprising a vibration sensitive device resting on the drumhead of said acoustic drum and arranged on said acoustic drum by holding means comprising: a spring device attached to said vibration sensitive device for positioning and vibration sensitive device flexibility and resiliently on said drumhead; electrical conductor means coupled to said vibration sensitive device for transmitting an electrical signal from said vibration sensitive device; connector means coupled to said electrical conductor means to allow transmission of said electrical signal from said transmitter; and fastening means for fastening said holding means to the rim of said acoustic drum. ### Claim 17 (depends on 16) A transmitter according to claim 16, wherein said spring device includes a spacer and a pad of a softer material than the material of said spacer such that said vibration sensitive device is attached to the surface of said pad. ### Claim 18 (depends on 16) A transmitter according to claim 16, wherein said pad is made of plastic foam. ### Claim 19 (depends on 16) A transmitter according to claim 16, wherein said holding means has a substantially L-shape such that a top leg of said holding means forms a cover protruding above said drumhead in a plane substantially parallel to said drumhead, and a bottom leg of said holding means is arranged adjacent to said rim of said acoustic drum and attached thereto by said fastening means. ### Claim 20 (depends on 19) A transmitter according to claim 19, wherein said spring device is arranged on the surface of said cover facing said drumhead. ### Claim 21 (depends on 19) A transmitter according to claim 19, wherein said top leg and said bottom leg form a hook having a shape adapted to fit the shape of the edge of said rim of said acoustic drum. ### Claim 22 (depends on 19) A transmitter according to claim 19, wherein said electrical conductor means and said connector means are positioned within said holding means, said connector means positioned within said bottom leg of said holding means.