US3849679A - Electroacoustic transducer with controlled beam pattern - Google Patents
Electroacoustic transducer with controlled beam pattern Download PDFInfo
- Publication number
- US3849679A US3849679A US00024615A US2461570A US3849679A US 3849679 A US3849679 A US 3849679A US 00024615 A US00024615 A US 00024615A US 2461570 A US2461570 A US 2461570A US 3849679 A US3849679 A US 3849679A
- Authority
- US
- United States
- Prior art keywords
- diaphragm
- disc
- sound
- vibratile
- center portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000002093 peripheral effect Effects 0.000 claims abstract description 20
- 230000005855 radiation Effects 0.000 claims abstract description 18
- 230000000873 masking effect Effects 0.000 claims description 33
- 239000004020 conductor Substances 0.000 claims description 5
- 230000000694 effects Effects 0.000 claims description 4
- 230000003993 interaction Effects 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 4
- 238000006073 displacement reaction Methods 0.000 abstract description 6
- 239000000919 ceramic Substances 0.000 abstract description 4
- 230000005540 biological transmission Effects 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 1
- 241001097253 Tomato zonate spot virus Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
- G10K9/12—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated
- G10K9/122—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated using piezoelectric driving means
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R17/00—Piezoelectric transducers; Electrostrictive transducers
- H04R17/10—Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency
Definitions
- This invention relates to electroacoustic transducers, and more particularly to transducers especially adapted for radiating sound in a controlled beam pattern.
- an electroacoustic transducer assembly is to place 'a transducer element at the open end of a rigid housing structure for transmitting sonic energy.
- the element may also act as a housing closure.
- the transducer element includes a vibratile diaphragm driven by a piezoelectric disc, in a complex flexural mode of vibration.
- the vibrating diaphragm at its first overtone circular resonance mode, which occurs at approximately 3.9 times the fundamental resonance frequency.
- the center and outer peripheral portions of the diaphragm have displacements in opposite phase. That is, the center moves up while the periphery moves down, and vice versa, with flexure occurring about an annular node.
- This selected complex mode of vibration may be used to obtain a relatively broad directional pattern. It is possible to use this vibration mode to transmit relatively high intensity levels of sound in regions which are removed from the normal axis of the diaphragm. This form of transmission secures a more uniform sound distribution over a relatively large area in front of the vibrating diaphragm.
- a square, freely suspended bilaminar transducer element may be driven at its fundamental flexural resonant mode.
- the four corners of this element vibrate in phase with each other.
- the phase of the corner displacements is opposite to the phase of the center displacement.
- a sound opaque mask may be mounted in close proximity to the center portion of the vibrating plate.
- the center of the flexural plate is not able to radiate the out of phase vibrations into the medium receiving the sonic energy.
- an object of this invention is to provide new and improved electroacoustic transducers with better performance characteristics.
- Another object of this invention is to provide vibra tile diaphragms which produce concentrated beams of sound radiation at a specific operating frequency.
- a further object of this invention is to provide inexpensive diaphragm assemblies which may also act as closures for the open ends of rigid housing structures.
- Yet another object of this invention is to provide vibratile diaphragms which operate in desired overtone resonance modes, when driven at a specified frequency.
- a vibratile diaphragm driven by a piezoelectric transducer element, which is preferably a ceramic material.
- diaphragm vibrates in a specific overtone mode, selected to provide a beam-like pattern in a sound field.
- the energy distribution of this sound field is more concentrated in a beam extending outwardly from the transducer, along an axis normal to the surface of the vibratile diaphragm, than it would be concentrated if the same diaphragm were operating at its fundamental resonance mode.
- FIG. 1 is a plan view of the top or diaphragm side of a transducer incorporating one embodiment of this invention
- FIG. 2 is a cross-sectional view of the transducer taken along the line 22 of FIG. 1;
- FIG. 3 schematically illustrates the peak amplitude displacement of the diaphragm when it is driven at its first overtone, nodal circle, resonant frequency
- FIG. 4 is a schematic representation of an edgemounted diaphragm with a masking plate closely positioned near the center portion of the diaphragm;
- FIG. 5 is another schematic representation, which is similar to the representation illustrated in FIG. 4; however, the masking plate is moved to a preferred distance away from the diaphragm surface;
- FIG. 6 is yet another schematic representation wherein the masking plate is undercut so that only the peripheral edge of the plate is in close proximity to the diaphragm surface.
- a section of cylindrical tubing 10 serves as a housing for the transducer assembly.
- a steplike annular recess 11 is machined into each end of the inner wall of the cylindrical tubing to provide a shoulder for supporting portions of the transducer assembly, and particularly a bilaminar vibratile assembly 12, 13.
- a circular diaphragm 12 has a piezoelectric disc 13 attached to its center by means of a suitable rigid cement, such as epoxy.
- a suitable rigid cement such as epoxy.
- the relationship between the thicknesses and diameters of the ceramic disc 13, and the clamped diaphragm 12, are selected so that the first overtone concentric resonance mode of the bilaminar assembly, occurs at the desired frequency of operation. as illustrated in FIG. 3.
- the optimum diameter for the piezoelectric disc 13 lies in a range extending from about one-fourth to one-half the diameter of the diaphragm 12.
- An alternate possibility is to use a ceramic disc 13 which covers the entire surface of the diaphragm 12.
- a waterproof cement may be applied to the periphery of the diaphragm. This waterproof sea] is formed between the edge of the diaphragm and the shoulder 11 of the housing surface.
- a sound masking plate structure 15 is positioned over the central part of the disc.
- This mask comprises a central circular disc portion held by three radial spoke-like members 17-19.
- a spacing washer 20 is located over the spokes, as illustrated in FIG. 2.
- the outer edge of the housing wall is crimped over at 21. This crimp locks the outer periphery of the masking plate structure 15 to thereby complete the assembly and provide a closure for the transducer housing 10.
- the opposite and open end of the housing is closed with a waterproof seal by a plate member 25 having an opening therein for giving passage to a cable 26.
- the cable 26 is sealed to the center opening in plate 25 by means of a rubber seal 27.
- the conductors in cable 26 are electrically connected to the ceramic disc by means of wires 28 and 29.
- the lower peripheral edge of housing is crimped at 30 to completely seal the transducer assembly.
- FIGS. 4, 5, and 6 diagramatically illustrate various arrangments for constructing and spacing the sound masking plate in relation to the diaphragm 12.
- the term sound baffle is used herein as generically descriptive of the structure shown in FIGS. 4-6.
- the sound masking disc 5, of FIG. 2 is schematically represented by the disc 32 in FIG. 4.
- the vibratile diaphragm 12, of FIG. 2 is schematically represented by the diaphragm 33 in FIG. 4.
- the schematic arrangement of FIG. 4 places the sound masking disc 32 is very closely spaced proximity S1 to the diaphragm 33. Therefore, sound radiating from the center portion of the diaphragm is prevented from being transmitted to the driven medium.
- the spacing 81 between the diaphragm 33 and sound masking plate 32 is sufficiently small, there is a thin air film having a viscosity which causes an absorption of the sound radiated from the center portion of the diaphragm.
- space S1 is less than onetenth the diameter of the masking plate.
- the diameter of the masking plate 32 should be made approximately equal to the nodal diameter D of the diaphragm 12 (FIG. 3). This nodal diameter D is somewhat less than one-half the diameter of the diaphragm. The exact nodal diameter D may be determined experimentally by observing a dust pattern on the vibrating diaphragm when it is driven at its desired overtone frequency.
- FIG. 5 illustrates another embodiment of the invention for enabling the sound radiation from the center portion of the diaphragm to combine with and enhance the sound radiation from the peripheral portion of the diaphragm.
- This enhancement is achieved by adjusting the spacing S2 so that the annular area represented by spacing S2 multiplied by the periphery of the sound masking disc 37, is approximately equal to the area of the masking disc 37.
- a further requirement to be satistied in order to achieve the enhancement is that the average phase of the sound coming from the center region of the diaphragm is delayed by approximately onehalf wavelength. This delay condition is achieved if the radius R of the masking plate 37 lies in the region extending from approximately one-fourth wavelength to one-half wavelength of the frequency of operation.
- the phase of the sound radiated from the center portion of the diaphragm destructively interferes with the sound radiated from the outer portion of the diaphragm. This interference causes a reduction in total radiation. If the radius R is larger than one-half wavelength, destructive interference also takes place for the sound energy generated by the center portion of the diaphragm. Therefore, this energy does not reach the region lying beyond the periphery of the sound masking disc 37.
- Yet another embodiment of the invention prevents radiation from the center portion of the diaphragm (FIG. 6).
- the sound masking plate 43 has an undercut area forming a cavity 44. The peripheral edge surrounding the undercut area is then placed in close proximity to the diaphragm 45.
- there is an air chamber with a volume 44 terminated at a thin annular slit.
- This provides a low pass acoustic filter that prevents the transmission of the sound energy generated by the center portion of the diaphragm, provided that the cut-off frequency of the filter is made to lie below the frequency of the transducer operation.
- the low frequency cut-off of the acoustic filter is easily controlled by a proper selection of the spacing between the masking plate periphery and the surface of the diaphragm 45.
- the principles required to make this selection are well known in the art of acoustic engineering.
- a wide range of operating frequencies and dimensions of structure may be chosen to satisfy any specific application requirement of a particular transducer design.
- spacing S1 provides one alternative for absorbing sonic energy
- spacing S2 provides another alternative for enhancing sonic energy.
- the term selective is used in the appended claims to mean the state of being wherein one of the alternatives is selected by the nature of the structure.
- An electroacoustic transducer comprising a tubular housing open on at least one end, vibratile diaphragm means having a center portion and an outer peripheral portion, means for sealing the periphery of said vibratile diaphragm to close the open end of said tubular housing and form a clamped vibratile disc, transducer means comprising a piezoelectric disc rigidly bonded to one side of said diaphragm, electrical conductor means attached to said piezoelectric disc for imparting electrical signals thereto, the center and peripheral portions vibrating in different modes which give rise to alternative sonic effects depending upon the degree of interaction between said modes of vibration, and sound baffle means for controlling the radiation of sound from the center portion of said diaphragm as compared with the radiation of sound from the outer peripheral portion of said diaphragm, said vibratile diaphragm operating at its overtone resonant frequency mode of operation, wherein said means for controlling the sound radiating from the center portion comprises a rigid sound masking disc positioned over the
- An electroacoustic transducer comprising a tubular housing open on at least one end, vibratile diaphragm means having a center portion and an outer peripheral portion, means for sealing the periphery of said vibratile diaphragm to close the open end of said tubular housing and form a clamped vibratile disc, transducer means comprising a piezoelectric disc rigidly bonded to one side of said diaphragm, electrical conductor means attached to said piezoelectric disc for imparting electrical signals thereto, the center and peripheral portions vibrating in different modes which give rise to alternative sonic effects depending upon the degree of interaction between said modes of vibration, and sound baffle means for controlling the radiation of sound from the center portion of said diaphragm as compared with the radiation of sound from the outer peripheral portion of said diaphragm, said vibratile diaphragm operating at its overtone resonant frequency mode of operation, wherein said means for controlling the sound radiating from the center portion comprises a rigid sound masking disc positioned over the
Abstract
Description
Claims (2)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US00024615A US3849679A (en) | 1970-02-12 | 1970-04-01 | Electroacoustic transducer with controlled beam pattern |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US1074870A | 1970-02-12 | 1970-02-12 | |
US1743070A | 1970-03-09 | 1970-03-09 | |
US00024615A US3849679A (en) | 1970-02-12 | 1970-04-01 | Electroacoustic transducer with controlled beam pattern |
Publications (1)
Publication Number | Publication Date |
---|---|
US3849679A true US3849679A (en) | 1974-11-19 |
Family
ID=27359300
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US00024615A Expired - Lifetime US3849679A (en) | 1970-02-12 | 1970-04-01 | Electroacoustic transducer with controlled beam pattern |
Country Status (1)
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US (1) | US3849679A (en) |
Cited By (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4188612A (en) * | 1978-05-01 | 1980-02-12 | Teledyne Industries Inc. (Geotech Division) | Piezoelectric seismometer |
US4190783A (en) * | 1978-07-25 | 1980-02-26 | The Stoneleigh Trust, Fred M. Dellorfano, Jr. & Donald P. Massa, Trustees | Electroacoustic transducers of the bi-laminar flexural vibrating type with an acoustic delay line |
US4191904A (en) * | 1978-09-28 | 1980-03-04 | Fred M. Dellorfano, Jr. | Electroacoustic transducers of the flexural resonant vibratile type |
US4228379A (en) * | 1978-08-28 | 1980-10-14 | American District Telegraph Company | Diaphragm type piezoelectric electroacoustic transducer |
US4260928A (en) * | 1978-11-09 | 1981-04-07 | General Electric Company | Electro-acoustic transducer with horn and reflector |
US4273399A (en) * | 1979-11-05 | 1981-06-16 | Amp Incorporated | Transducer supporting and contacting means |
US4333028A (en) * | 1980-04-21 | 1982-06-01 | Milltronics Ltd. | Damped acoustic transducers with piezoelectric drivers |
EP0080100A1 (en) * | 1981-11-17 | 1983-06-01 | Matsushita Electric Industrial Co., Ltd. | Ultrasonic transducer |
US4768615A (en) * | 1986-01-27 | 1988-09-06 | Endress U. Hauser Gmbh U. Co. | Acoustic transducer system |
US5218575A (en) * | 1992-09-04 | 1993-06-08 | Milltronics Ltd. | Acoustic transducer |
US5452267A (en) * | 1994-01-27 | 1995-09-19 | Magnetrol International, Inc. | Midrange ultrasonic transducer |
US5955824A (en) * | 1996-08-13 | 1999-09-21 | Murata Manufacturing Co., Ltd. | Reduced size electro-acoustic transducer with improved terminal |
US20030091199A1 (en) * | 2001-10-24 | 2003-05-15 | Horrall Thomas R. | Sound masking system |
US20030219133A1 (en) * | 2001-10-24 | 2003-11-27 | Acentech, Inc. | Sound masking system |
US20080097216A1 (en) * | 2006-09-18 | 2008-04-24 | Liposonix, Inc. | Transducer with shield |
US20110140573A1 (en) * | 2006-09-18 | 2011-06-16 | Medicis Technologies Corporation | Transducer with shield |
WO2011090484A1 (en) * | 2010-01-22 | 2011-07-28 | Massa Products Corporation | Hidden ultrasonic transducer |
US20140328504A1 (en) * | 2011-11-29 | 2014-11-06 | Qualcomm Mems Technologies, Inc. | Transducer with piezoelectric, conductive and dielectric membrane |
US9179219B2 (en) | 2011-11-09 | 2015-11-03 | Airmar Technology Corporation | Widebeam acoustic transducer |
RU2647509C1 (en) * | 2016-12-14 | 2018-03-16 | Владимир Борисович Комиссаренко | Electroacoustical transducer |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2967957A (en) * | 1957-09-17 | 1961-01-10 | Massa Frank | Electroacoustic transducer |
US3268855A (en) * | 1963-03-19 | 1966-08-23 | Electro Voice | Ultrasonic microphone |
US3271596A (en) * | 1963-11-12 | 1966-09-06 | Boeing Co | Electromechanical transducers |
US3518460A (en) * | 1968-10-30 | 1970-06-30 | Euphonics Corp | Ultrasonic transducer employing suspended piezoelectric plate |
US3577020A (en) * | 1969-06-17 | 1971-05-04 | Industrial Research Prod Inc | Acceleration insensitive transducer |
-
1970
- 1970-04-01 US US00024615A patent/US3849679A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2967957A (en) * | 1957-09-17 | 1961-01-10 | Massa Frank | Electroacoustic transducer |
US3268855A (en) * | 1963-03-19 | 1966-08-23 | Electro Voice | Ultrasonic microphone |
US3271596A (en) * | 1963-11-12 | 1966-09-06 | Boeing Co | Electromechanical transducers |
US3518460A (en) * | 1968-10-30 | 1970-06-30 | Euphonics Corp | Ultrasonic transducer employing suspended piezoelectric plate |
US3577020A (en) * | 1969-06-17 | 1971-05-04 | Industrial Research Prod Inc | Acceleration insensitive transducer |
Cited By (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4188612A (en) * | 1978-05-01 | 1980-02-12 | Teledyne Industries Inc. (Geotech Division) | Piezoelectric seismometer |
US4190783A (en) * | 1978-07-25 | 1980-02-26 | The Stoneleigh Trust, Fred M. Dellorfano, Jr. & Donald P. Massa, Trustees | Electroacoustic transducers of the bi-laminar flexural vibrating type with an acoustic delay line |
US4228379A (en) * | 1978-08-28 | 1980-10-14 | American District Telegraph Company | Diaphragm type piezoelectric electroacoustic transducer |
US4191904A (en) * | 1978-09-28 | 1980-03-04 | Fred M. Dellorfano, Jr. | Electroacoustic transducers of the flexural resonant vibratile type |
US4260928A (en) * | 1978-11-09 | 1981-04-07 | General Electric Company | Electro-acoustic transducer with horn and reflector |
US4273399A (en) * | 1979-11-05 | 1981-06-16 | Amp Incorporated | Transducer supporting and contacting means |
US4333028A (en) * | 1980-04-21 | 1982-06-01 | Milltronics Ltd. | Damped acoustic transducers with piezoelectric drivers |
EP0080100A1 (en) * | 1981-11-17 | 1983-06-01 | Matsushita Electric Industrial Co., Ltd. | Ultrasonic transducer |
US4768615A (en) * | 1986-01-27 | 1988-09-06 | Endress U. Hauser Gmbh U. Co. | Acoustic transducer system |
AU577721B2 (en) * | 1986-01-27 | 1988-09-29 | Endress & Hauser Gmbh & Co. | Acoustic transducer system |
US5218575A (en) * | 1992-09-04 | 1993-06-08 | Milltronics Ltd. | Acoustic transducer |
US5452267A (en) * | 1994-01-27 | 1995-09-19 | Magnetrol International, Inc. | Midrange ultrasonic transducer |
US5955824A (en) * | 1996-08-13 | 1999-09-21 | Murata Manufacturing Co., Ltd. | Reduced size electro-acoustic transducer with improved terminal |
US20030219133A1 (en) * | 2001-10-24 | 2003-11-27 | Acentech, Inc. | Sound masking system |
US20030091199A1 (en) * | 2001-10-24 | 2003-05-15 | Horrall Thomas R. | Sound masking system |
US7194094B2 (en) | 2001-10-24 | 2007-03-20 | Acentech, Inc. | Sound masking system |
US20070133816A1 (en) * | 2001-10-24 | 2007-06-14 | Horrall Thomas R | Sound masking system |
US10555078B2 (en) | 2001-10-24 | 2020-02-04 | Cambridge Sound Management, Inc. | Sound masking system |
US11700483B2 (en) | 2001-10-24 | 2023-07-11 | Cambridge Sound Management, Inc. | Sound masking system |
US9820040B2 (en) | 2001-10-24 | 2017-11-14 | Cambridge Sound Management, Inc. | Sound masking system |
US9076430B2 (en) | 2001-10-24 | 2015-07-07 | Cambridge Sound Management, Inc. | Sound masking system |
US20080097216A1 (en) * | 2006-09-18 | 2008-04-24 | Liposonix, Inc. | Transducer with shield |
US8334637B2 (en) * | 2006-09-18 | 2012-12-18 | Liposonix, Inc. | Transducer with shield |
US20110140573A1 (en) * | 2006-09-18 | 2011-06-16 | Medicis Technologies Corporation | Transducer with shield |
US7652411B2 (en) * | 2006-09-18 | 2010-01-26 | Medicis Technologies Corporation | Transducer with shield |
WO2011090484A1 (en) * | 2010-01-22 | 2011-07-28 | Massa Products Corporation | Hidden ultrasonic transducer |
US9179219B2 (en) | 2011-11-09 | 2015-11-03 | Airmar Technology Corporation | Widebeam acoustic transducer |
US20140328504A1 (en) * | 2011-11-29 | 2014-11-06 | Qualcomm Mems Technologies, Inc. | Transducer with piezoelectric, conductive and dielectric membrane |
US10003888B2 (en) * | 2011-11-29 | 2018-06-19 | Snaptrack, Inc | Transducer with piezoelectric, conductive and dielectric membrane |
US10735865B2 (en) | 2011-11-29 | 2020-08-04 | Snaptrack, Inc. | Transducer with piezoelectric, conductive and dielectric membrane |
RU2647509C1 (en) * | 2016-12-14 | 2018-03-16 | Владимир Борисович Комиссаренко | Electroacoustical transducer |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: TRUSTEES FOR AND ON BEHALF OF THE D.P. MASSA TRUST Free format text: ASSIGN TO TRUSTEES AS EQUAL TENANTS IN COMMON, THE ENTIRE INTEREST.;ASSIGNORS:MASSA, DONALD P.;MASSA, CONSTANCE A.;MASSA, GEORGIANA M.;AND OTHERS;REEL/FRAME:005395/0942 Effective date: 19841223 Owner name: MASSA, DONALD P., COHASSET, MA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:STONELEIGH TRUST, THE;REEL/FRAME:005397/0016 Effective date: 19841223 Owner name: DELLORFANO, FRED M. JR. Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:STONELEIGH TRUST, THE;REEL/FRAME:005397/0016 Effective date: 19841223 Owner name: MASSA PRODUCTS CORPORATION, 280 LINCOLN STREET, HI Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:DONALD P. MASSA TRUST;CONSTANCE ANN MASSA TRUST;ROBERT MASSA TRUST;AND OTHERS;REEL/FRAME:005395/0971 Effective date: 19860612 Owner name: MASSA PRODUCTS CORPORATION, 80 LINCOLN STREET, HIN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:DONALD P. MASSA TRUST;CONSTANCE ANN MASSA TRUST *;GEORGIANA M. MASSA TRUST;AND OTHERS;REEL/FRAME:005395/0954 Effective date: 19841223 |