US2313129A - Art of mounting piezoelectric crystals - Google Patents
Art of mounting piezoelectric crystals Download PDFInfo
- Publication number
- US2313129A US2313129A US376874A US37687441A US2313129A US 2313129 A US2313129 A US 2313129A US 376874 A US376874 A US 376874A US 37687441 A US37687441 A US 37687441A US 2313129 A US2313129 A US 2313129A
- Authority
- US
- United States
- Prior art keywords
- crystal
- art
- piezoelectric crystals
- mounting piezoelectric
- lanolin
- 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
- 239000013078 crystal Substances 0.000 title description 32
- 239000004166 Lanolin Substances 0.000 description 8
- 229940039717 lanolin Drugs 0.000 description 8
- 235000019388 lanolin Nutrition 0.000 description 8
- 239000011810 insulating material Substances 0.000 description 7
- LJCNRYVRMXRIQR-OLXYHTOASA-L potassium sodium L-tartrate Chemical compound [Na+].[K+].[O-]C(=O)[C@H](O)[C@@H](O)C([O-])=O LJCNRYVRMXRIQR-OLXYHTOASA-L 0.000 description 7
- 235000011006 sodium potassium tartrate Nutrition 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 238000000576 coating method Methods 0.000 description 6
- 239000004264 Petrolatum Substances 0.000 description 5
- 229940066842 petrolatum Drugs 0.000 description 5
- 235000019271 petrolatum Nutrition 0.000 description 5
- 239000003995 emulsifying agent Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- CEGOLXSVJUTHNZ-UHFFFAOYSA-K aluminium tristearate Chemical compound [Al+3].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O CEGOLXSVJUTHNZ-UHFFFAOYSA-K 0.000 description 1
- 229940063655 aluminum stearate Drugs 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000012056 semi-solid material Substances 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000001476 sodium potassium tartrate Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000001993 wax Substances 0.000 description 1
Images
Classifications
-
- 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
- H04R17/04—Gramophone pick-ups using a stylus; Recorders using a stylus
Definitions
- My present invention relates to the art of mounting piezoelectric crystal elements, particularly those constituted of Rochelle salt (sodiumpotassium tartrate) .and has for its principal object to provide improvements in moisture-'proof mounts for such piezoelectric crystal elements.
- Rochelle salt sodiumpotassium tartrate
- I may surround, immerse or em'bed a Rochelle salt or similar crystal elementor elements, and preferably the electrodes therefor, in petroleum, or in lanolin, or in a mixture comprising petrolatum and lanolin or other water emulsifying agent, such for example as calcium stearato or aluminum stearate.
- these moisture-proofing substances or mixtures are applied in the form of a filling to the casing or cartridge in which the crystal assembly is mounted, in which case the crystal and its electrodes are allv preferably immersed in and surrounded by the illling.
- a Rochelle salt crystal which is mounted and operated in accordance with my invention in petrolatum exhibits a substantially higher factor or merit than one provided with an asphaltic coating.
- I have achieved very much better results when the embedment material is constituted in whole or in part of lanolin or other emulsifying agent.
- a Rochelle salt crystal element coated with an asphaltic compound exhibited a useful life of 24 hours, one embedded in petrolatum a useful life of 300 hours, while one embedded in lanolin was apparently unaffected at the expiration of 500 hours.
- the failure of the first mentioned crystal may have been due to minute voids, inherent in the granular structure of asphaltic coatings, through which moisture seeped 4and destroyed the crystal. 'I'he eventual failure of the crystals which were embedded in petrolatum may be attributed to the factvthat moisture settling on the petrolatum eventually worked inwardly through the mass and was absorbed by .the crystal.
- lanolin lanum anhydrous U. S. P.
- this material has a melting point of 31 to 34 C. and has a viscosity such that it serves not only to damp-out resonance peaks. (at temperature of the order of 20 to 25 C.) but also serves to compensate for the usual drop in the crystal output at temperatures above 20 C., by reason of its decreased viscosity at increasing temperatures.
- lanolin is capable of absorbing up to percent of its weight of water although it is not water soluble. The advantages of my invention, however, may be achieved to a greater or less degree, in the above respects, with any of the aforementioned or equivalent semiliquid or semisolid materials, either alone or in combination.
- a conventional phonograph pick-up comprising a casing I which encloses a piezoelectric unit comprising a pair of Rochelle salt crystals 3 with which are associated terminal foils B of conductive material in a well known manner, the crystal unit 3 being spaced from the casing I as by the clamps 'l in which it is supported, or otherwise.
- the casing i also carries a torsion yoke 9 which extends through a suitable bearing i I, and. the outer or free-end of the yoke 9 being provided. with a needle socket I3.
- the casing is provided with a illling comprising a semisolid or semiliq'uid mass which is preferably constituted of one of the insulating materials or compoundsl above described and within which the crystal unit 3 is adapted to be vibrated as by the force transmitted thereto through the yoke 9. l
- a piezoelectric unit comprising a. casing containing a piezoelectric crystal element and a semisolid mass of insulating material in which said crystal is embedded, and means extending from said crystal throush said insulating material to the exterior oi said casing for applying an operating force to said crystal.
- said insulating material comprises a water emulsiiying agent.
- said insulating material comprises petro- WmusMnDoHAN.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
- Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
- Piezo-Electric Transducers For Audible Bands (AREA)
Description
March 9, 1943. w. R. DOHAN 2,313,129t
ART OF MOUNTING PIEZOELECTRIC CRYSTALS Filed Jan. 51, 1941 Patented Mu. s, 1943 ABT F MOUNTING PIEZOELECTRIC OEYBTAIB `William B. Dohan. Wynnewood, Pa., assigner to Radio Corporation of America, a corporation of Delaware Application January 3l, 1941, Serial No. 376,874
(Cl. lll-327) 5 Claims.
My present invention relates to the art of mounting piezoelectric crystal elements, particularly those constituted of Rochelle salt (sodiumpotassium tartrate) .and has for its principal object to provide improvements in moisture-'proof mounts for such piezoelectric crystal elements.
Other objects and advantages will be apparent and my invention itself will be best understood dehydrate; at humidities higher than 87.2 percent they will slowly dissolve. In either event the useful piezoelectric properties of such crystal elements are destroyed.
Since the above described conditions of humidity may be encountered (particularly in tropical countries) in normal use, various means have heretofore been proposed for protecting Rochelle salt and similar crystal elements from excessive hydration and dehydration. By way of example, it has previously been proposed to enclose the crystals in hermetically sealed envelopes and/or to coat them with certain asphaltic or wax compounds. However the necessity of transmitting mechanical vibrations to the crystal or crystals (as in phonograph pickups") renders it dimcult to maintain a hermetic seal about the crystal and, as will hereinafter more fully appear, conventional rigid coatings lprovide but little real protection for the crystal. In this latter connection it may be observed that to increase the thickness of a wax-like or asphaltic coating with a view to increasing its protective qualities may result in undue damping of the crystal vibrations.
I have discovered that the foregoing objections to the moisture-proof coatings of the prior art are substantially' obviated by the use of certain semisolid or semiiluid embedments. Thus. I may surround, immerse or em'bed a Rochelle salt or similar crystal elementor elements, and preferably the electrodes therefor, in petroleum, or in lanolin, or in a mixture comprising petrolatum and lanolin or other water emulsifying agent, such for example as calcium stearato or aluminum stearate. l Preferably these moisture-proofing substances or mixtures are applied in the form of a filling to the casing or cartridge in which the crystal assembly is mounted, in which case the crystal and its electrodes are allv preferably immersed in and surrounded by the illling.
While a Rochelle salt crystal which is mounted and operated in accordance with my invention in petrolatum exhibits a substantially higher factor or merit than one provided with an asphaltic coating. I have achieved very much better results when the embedment material is constituted in whole or in part of lanolin or other emulsifying agent. By way of example: under similar yextreme conditions (90 percent relative humidity) a Rochelle salt crystal element coated with an asphaltic compound exhibited a useful life of 24 hours, one embedded in petrolatum a useful life of 300 hours, while one embedded in lanolin was apparently unaffected at the expiration of 500 hours. The failure of the first mentioned crystal may have been due to minute voids, inherent in the granular structure of asphaltic coatings, through which moisture seeped 4and destroyed the crystal. 'I'he eventual failure of the crystals which were embedded in petrolatum may be attributed to the factvthat moisture settling on the petrolatum eventually worked inwardly through the mass and was absorbed by .the crystal.
I attribute the vastly superior protective action of the lanolin, and of the other water emulsifying agents, to the fact that these materials hold themoisture in the dispersed phase. That is to say, the ilne particles or globules of water apparently become coated with the embedment material so that if or when these coated liquid particles reach the region of the crystal, the coatings (i. e., the continuous phase of the emulsion) on these discrete particles inhibit or prevent actual contact of the water with the crystal so that it can not be absorbed by the crystal.
Of the emulsifying agents, above mentioned, I prefer lanolin (lanum anhydrous U. S. P.), as this material has a melting point of 31 to 34 C. and has a viscosity such that it serves not only to damp-out resonance peaks. (at temperature of the order of 20 to 25 C.) but also serves to compensate for the usual drop in the crystal output at temperatures above 20 C., by reason of its decreased viscosity at increasing temperatures. Further, lanolin is capable of absorbing up to percent of its weight of water although it is not water soluble. The advantages of my invention, however, may be achieved to a greater or less degree, in the above respects, with any of the aforementioned or equivalent semiliquid or semisolid materials, either alone or in combination.
In the accompanying drawing I have shown the invention as applied to a conventional phonograph pick-up comprising a casing I which encloses a piezoelectric unit comprising a pair of Rochelle salt crystals 3 with which are associated terminal foils B of conductive material in a well known manner, the crystal unit 3 being spaced from the casing I as by the clamps 'l in which it is supported, or otherwise. As in standard practice the casing i also carries a torsion yoke 9 which extends through a suitable bearing i I, and. the outer or free-end of the yoke 9 being provided. with a needle socket I3. In accordance with my invention the casing is provided with a illling comprising a semisolid or semiliq'uid mass which is preferably constituted of one of the insulating materials or compoundsl above described and within which the crystal unit 3 is adapted to be vibrated as by the force transmitted thereto through the yoke 9. l
Various modifications of my invention will suggest themselves to thosel skilled in the art. It t to be understood, therefore. that the foregoing should be interpreted as illustrative and not in a limiting sense except as required by the prior art and by the spirit oi the appended claims.
I claim:
l 1. A piezoelectric unit comprising a. casing containing a piezoelectric crystal element and a semisolid mass of insulating material in which said crystal is embedded, and means extending from said crystal throush said insulating material to the exterior oi said casing for applying an operating force to said crystal.
2. The invention as set forth in claim 1 and wherein said insulating material comprises a water emulsiiying agent.
3. The invention as set forth in claim 1 and wherein said insulating material comprises lanolin.
4. The invention as set forth in claim 1 and wherein said insulating material comprises a water-insoluble metallic soap.
5. The invention as set forth in claim 1 and Jvltierein said insulating material comprises petro- WmusMnDoHAN.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE474895D BE474895A (en) | 1941-01-31 | ||
| US376874A US2313129A (en) | 1941-01-31 | 1941-01-31 | Art of mounting piezoelectric crystals |
| GB12165/41A GB551954A (en) | 1941-01-31 | 1941-09-19 | Improvements in or relating to the mounting of piezoelectric crystals |
| FR950240D FR950240A (en) | 1941-01-31 | 1947-07-28 | Mounting of piezoelectric crystals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US376874A US2313129A (en) | 1941-01-31 | 1941-01-31 | Art of mounting piezoelectric crystals |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2313129A true US2313129A (en) | 1943-03-09 |
Family
ID=23486852
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US376874A Expired - Lifetime US2313129A (en) | 1941-01-31 | 1941-01-31 | Art of mounting piezoelectric crystals |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US2313129A (en) |
| BE (1) | BE474895A (en) |
| FR (1) | FR950240A (en) |
| GB (1) | GB551954A (en) |
Cited By (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2476414A (en) * | 1945-05-24 | 1949-07-19 | William H Hutter | Phonograph pickup having plastic torsion arm |
| US2498210A (en) * | 1948-11-02 | 1950-02-21 | Avco Mfg Corp | Piezoelectric phonograph pickup device |
| US2510585A (en) * | 1945-08-21 | 1950-06-06 | Rca Corp | Dynamic galvanometer |
| US2510342A (en) * | 1946-04-03 | 1950-06-06 | Avco Mfg Corp | Pickup mounting |
| US2518861A (en) * | 1947-03-21 | 1950-08-15 | Brush Dev Co | Phonograph pickup |
| US2519185A (en) * | 1947-03-21 | 1950-08-15 | Brush Dev Co | Phonograph pickup |
| US2539297A (en) * | 1947-02-27 | 1951-01-23 | Lazaro Luis Nicolas Gomez De | Electric musical instrument |
| US2562741A (en) * | 1947-02-13 | 1951-07-31 | Dictaphone Corp | Method of making sealed electromechanical translating devices |
| US2564054A (en) * | 1947-10-10 | 1951-08-14 | Magnavox Co | Phonograph pickup and mechanical motion converting system therefor |
| US2565837A (en) * | 1944-05-03 | 1951-08-28 | Ansar Anders Johan | Pickup device having a force transmitting carrier link of viscous material |
| US2594948A (en) * | 1947-10-30 | 1952-04-29 | Brush Dev Co | Electromechanical transducer unit |
| US2701280A (en) * | 1950-03-02 | 1955-02-01 | Emi Ltd | Piezoelectric phonograph pickup |
| DE1026980B (en) * | 1952-03-27 | 1958-03-27 | Electroacustik Ges M B H | Piezoelectric pickup |
| DE1026979B (en) * | 1952-03-13 | 1958-03-27 | Electroacustik Ges M B H | Device for establishing a detachable connection between a pickup and a scanning element |
| US2839695A (en) * | 1957-01-31 | 1958-06-17 | Donald H Robey | Frequency controllable piezo-electric resonator |
| US2879413A (en) * | 1956-08-21 | 1959-03-24 | Sonotone Corp | Phonograph pickups |
| DE1053802B (en) * | 1953-05-28 | 1959-03-26 | Tefi Appbau Dr Daniel K G | Method of manufacturing a piezoelectric pickup |
| DE1150215B (en) * | 1958-04-03 | 1963-06-12 | Erie Resistor Corp | Pickup for sampling stereophonically and monaurally recorded signals |
| US3239696A (en) * | 1962-06-20 | 1966-03-08 | Garrett Corp | Piezoelectric pressure transducer |
| US3374663A (en) * | 1965-04-16 | 1968-03-26 | Electronic Systems Inc | Vibration detector |
| US3465747A (en) * | 1964-11-17 | 1969-09-09 | Vernon L Rogallo | Ballistocardiograph |
| US3582692A (en) * | 1968-05-01 | 1971-06-01 | U S Research Corp | Resiliently supported sensing transducer |
| US4051396A (en) * | 1974-02-28 | 1977-09-27 | Channel Products, Inc. | Encapsulation to prevent fracture of piezoelectric high voltage mechanism |
| WO1984001499A1 (en) * | 1982-10-19 | 1984-04-26 | Ivac Corp | Electronic sphygmomanometer |
| US7622844B1 (en) * | 2003-12-30 | 2009-11-24 | Hipercon, Llc | Metal fiber brush interface conditioning |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1029173B (en) * | 1952-09-15 | 1958-04-30 | Daniel Tefi Apparatebau | Piezoelectric pickup |
-
0
- BE BE474895D patent/BE474895A/xx unknown
-
1941
- 1941-01-31 US US376874A patent/US2313129A/en not_active Expired - Lifetime
- 1941-09-19 GB GB12165/41A patent/GB551954A/en not_active Expired
-
1947
- 1947-07-28 FR FR950240D patent/FR950240A/en not_active Expired
Cited By (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2565837A (en) * | 1944-05-03 | 1951-08-28 | Ansar Anders Johan | Pickup device having a force transmitting carrier link of viscous material |
| US2476414A (en) * | 1945-05-24 | 1949-07-19 | William H Hutter | Phonograph pickup having plastic torsion arm |
| US2510585A (en) * | 1945-08-21 | 1950-06-06 | Rca Corp | Dynamic galvanometer |
| US2510342A (en) * | 1946-04-03 | 1950-06-06 | Avco Mfg Corp | Pickup mounting |
| US2562741A (en) * | 1947-02-13 | 1951-07-31 | Dictaphone Corp | Method of making sealed electromechanical translating devices |
| US2539297A (en) * | 1947-02-27 | 1951-01-23 | Lazaro Luis Nicolas Gomez De | Electric musical instrument |
| US2518861A (en) * | 1947-03-21 | 1950-08-15 | Brush Dev Co | Phonograph pickup |
| US2519185A (en) * | 1947-03-21 | 1950-08-15 | Brush Dev Co | Phonograph pickup |
| US2564054A (en) * | 1947-10-10 | 1951-08-14 | Magnavox Co | Phonograph pickup and mechanical motion converting system therefor |
| US2594948A (en) * | 1947-10-30 | 1952-04-29 | Brush Dev Co | Electromechanical transducer unit |
| US2498210A (en) * | 1948-11-02 | 1950-02-21 | Avco Mfg Corp | Piezoelectric phonograph pickup device |
| US2701280A (en) * | 1950-03-02 | 1955-02-01 | Emi Ltd | Piezoelectric phonograph pickup |
| DE1026979B (en) * | 1952-03-13 | 1958-03-27 | Electroacustik Ges M B H | Device for establishing a detachable connection between a pickup and a scanning element |
| DE1026980B (en) * | 1952-03-27 | 1958-03-27 | Electroacustik Ges M B H | Piezoelectric pickup |
| DE1053802B (en) * | 1953-05-28 | 1959-03-26 | Tefi Appbau Dr Daniel K G | Method of manufacturing a piezoelectric pickup |
| US2879413A (en) * | 1956-08-21 | 1959-03-24 | Sonotone Corp | Phonograph pickups |
| US2839695A (en) * | 1957-01-31 | 1958-06-17 | Donald H Robey | Frequency controllable piezo-electric resonator |
| DE1150215B (en) * | 1958-04-03 | 1963-06-12 | Erie Resistor Corp | Pickup for sampling stereophonically and monaurally recorded signals |
| US3239696A (en) * | 1962-06-20 | 1966-03-08 | Garrett Corp | Piezoelectric pressure transducer |
| US3465747A (en) * | 1964-11-17 | 1969-09-09 | Vernon L Rogallo | Ballistocardiograph |
| US3374663A (en) * | 1965-04-16 | 1968-03-26 | Electronic Systems Inc | Vibration detector |
| US3582692A (en) * | 1968-05-01 | 1971-06-01 | U S Research Corp | Resiliently supported sensing transducer |
| US4051396A (en) * | 1974-02-28 | 1977-09-27 | Channel Products, Inc. | Encapsulation to prevent fracture of piezoelectric high voltage mechanism |
| WO1984001499A1 (en) * | 1982-10-19 | 1984-04-26 | Ivac Corp | Electronic sphygmomanometer |
| US7622844B1 (en) * | 2003-12-30 | 2009-11-24 | Hipercon, Llc | Metal fiber brush interface conditioning |
Also Published As
| Publication number | Publication date |
|---|---|
| BE474895A (en) | |
| FR950240A (en) | 1949-09-21 |
| GB551954A (en) | 1943-03-17 |
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