US3745490A - Electromechanical filter - Google Patents

Electromechanical filter Download PDF

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Publication number
US3745490A
US3745490A US00182491A US3745490DA US3745490A US 3745490 A US3745490 A US 3745490A US 00182491 A US00182491 A US 00182491A US 3745490D A US3745490D A US 3745490DA US 3745490 A US3745490 A US 3745490A
Authority
US
United States
Prior art keywords
resonators
housing
filter
flexural
vibration
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
Application number
US00182491A
Other languages
English (en)
Inventor
K Traub
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from DE19702048162 external-priority patent/DE2048162C3/de
Application filed by Siemens AG filed Critical Siemens AG
Application granted granted Critical
Publication of US3745490A publication Critical patent/US3745490A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/48—Coupling means therefor
    • H03H9/50—Mechanical coupling means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/013—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for obtaining desired frequency or temperature coefficient
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49004—Electrical device making including measuring or testing of device or component part

Definitions

  • ABSTRACT Electromechanical filter consisting of several mechanically coupled, mechanical, flexural resonators which are arranged in a housing.
  • the filter is characterized in that a sound absorbing intermediate layer is inserted between the resonators and at least one wall of the housing.
  • the present invention relates to an electromechanical filter consisting of several mechanically coupled, mechanical, flexural resonators, arranged in a housing.
  • mechanical filters consist of several mechanically coupled mechanical resonators, in which the filter characteristic is determined by the vibration process of the resonators and couplers.
  • the use of the flexural mode of vibration for the resonator and the use of the longitudinal mode of vibration for the coupling elements is particularly advantageous as in the flexural mode of vibration the resonant frequency of the resonator is codetermined by the area moment of inertia effective in the direction of the vibration and, as with use of longitudinal couplers, relatively large band widths can be obtained even with relatively thin coupling wires.
  • the filter is generally accommodated within a housing for protection against external influences.
  • the air surrounding a mechanical filter is also excited to vibration by the motion of the individual resonators. Because of the low vibration of air, damping of the resonators, therefore, occurs. This damping is particularly pro-' nounced, and sometimes also accompanied by a detuning in frequency if, as a result of the internal dimensions of the housing, air spaces are generated which are in resonance with the operating frequency of the filter. The result is then distortion of the transfer characteristic of the filter at the resonant frequencies of these air spaces.
  • Flexural resonators for equal resonator dimensions, in comparison to resonators which execute other forms of vibration in general, have relatively large surfaces which, in the case of flexural vibration, are exposed to the air resistance. For this reason, the disturbing influences of air resonances of the transfer characteristics of the filter occur especially in filters with flexural resonators, if the dimensions of the housing are unfavorable.
  • the air space between them is alternatingly increased and decreased in this filter. Air waves are, thereby excited perpendicularly to the direction of vibration of the flexural resonators. These waves are reflected at the wall of the housing and can form standing waves.
  • the single FIGURE shows a mechanical filter consisting of several mechanical flexural resonators 1, which perform longitudinal vibrations, and which are coupled by a continuous mutual coupling element.
  • the end resonators are provided with electromechanical transducers 2 and 2' for conversion of electrical to me chanical vibrations or the conversion of mechanical to electrical vibrations, respectively.
  • the resonators which originally had circular cross section, are provided with a flat, at which support elements 4 are provided in the region of the vibration nodes. These support elements, in turn, are anchored on a base plate 5.
  • the resonators are shown so that their end face is visible.
  • the coupling element 3 is fastened to the individual resonators in their central region.
  • the resonators themselves, are arranged in one plane and are excited to perform flexural vibrations in such a manner that they execute these vibrations in the direction of the double arrow 6, Le. parallel to the base plate 5. Consequently, the coupling element 3 also vibrates longitudinally in the direction of the double arrow 6.
  • the filter is surrounded, on all sides, by a housing 7 in order to exclude external influences as far as possible.
  • An intermediate layer 8 consisting of sound absorbing material, which inhibits the air resonances occurring perpendicularly to the direction of vibration 6, is between the filter body and the wall of the housing.
  • plastic material namely polyester fabric, which has a thickness of 0.5 mm, is used as the material for the intermediatel layer 8. No attenuation distortion, caused by air resonances, was observed with this arrangement in the entire temperature range of interest, that is between 0 to 55C.
  • the intermediate layer 8 is placed directly on the resonators and specifically on the side opposite coupling element 3.
  • the intermediate layer 8, therefore, lies parallel to the direction of vibration 6 of the resonators and can extend, if necessary, over the entire length of the resonator as is shown.
  • the intermediate layer 8 need not be rigidly connected with the housing, but can rest, without detrimental effect on the transfer function

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Acoustics & Sound (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
  • Exhaust Silencers (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Developing Agents For Electrophotography (AREA)
  • Micromachines (AREA)
US00182491A 1970-09-29 1971-09-21 Electromechanical filter Expired - Lifetime US3745490A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE2047899A DE2047899C3 (de) 1970-09-29 1970-09-29 Verfahren zum Abgleich mechanischer Filter
DE19702048162 DE2048162C3 (de) 1970-09-30 Elektromechanisches Filter
DE19702048125 DE2048125C3 (de) 1970-09-30 Schaltungsanordnung zum Abgleich eines mechanischen Filters

Publications (1)

Publication Number Publication Date
US3745490A true US3745490A (en) 1973-07-10

Family

ID=27182895

Family Applications (2)

Application Number Title Priority Date Filing Date
US00182491A Expired - Lifetime US3745490A (en) 1970-09-29 1971-09-21 Electromechanical filter
US00183404A Expired - Lifetime US3823470A (en) 1970-09-29 1971-09-24 Method and apparatus for trimming mechanical filters

Family Applications After (1)

Application Number Title Priority Date Filing Date
US00183404A Expired - Lifetime US3823470A (en) 1970-09-29 1971-09-24 Method and apparatus for trimming mechanical filters

Country Status (11)

Country Link
US (2) US3745490A (xx)
AT (2) AT321366B (xx)
AU (1) AU465093B2 (xx)
BE (2) BE773271A (xx)
CA (2) CA965162A (xx)
CH (2) CH529476A (xx)
DE (1) DE2047899C3 (xx)
FR (2) FR2108670A5 (xx)
GB (2) GB1330215A (xx)
NL (2) NL7113314A (xx)
SE (2) SE362758B (xx)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3028991A1 (de) * 1980-07-30 1982-02-11 Siemens AG, 1000 Berlin und 8000 München Aus mechanischen resonatoren bestehendes elektromechanisches filter
US5740595A (en) * 1989-09-21 1998-04-21 Nihon Musen Kabushiki Kaisha Composite longitudinal vibration mechanical filter's method of manufacturing including undesired vibration absorber

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2608137C2 (de) * 1976-02-27 1983-09-01 Siemens AG, 1000 Berlin und 8000 München Verfahren zum Frequenzabgleich eines elektromechanischen Filters
US6791325B1 (en) * 2003-05-28 2004-09-14 Ge Medical Systems Global Technology Company, Llc Impedance mismatch apparatus and system for isolation of an MR imaging system

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2617882A (en) * 1950-05-29 1952-11-11 Rca Corp Maximal flatness filter
GB822536A (en) * 1956-12-06 1959-10-28 Standard Telephones Cables Ltd Improved mechanical filter having mechanical resonators coupled by means employing poisson's effect
GB947145A (en) * 1958-12-24 1964-01-22 Standard Telephones Cables Ltd Improvements in or relating to electromechanical filters
US3559256A (en) * 1968-03-12 1971-02-02 Jerome H Lemelson Machine control apparatus
US3621547A (en) * 1969-05-16 1971-11-23 Gen Electric Method for optimum mounting of piezoelectric ceramic filter elements
US3674995A (en) * 1970-08-31 1972-07-04 Texas Instruments Inc Computer controlled device testing and subsequent arbitrary adjustment of device characteristics

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3028991A1 (de) * 1980-07-30 1982-02-11 Siemens AG, 1000 Berlin und 8000 München Aus mechanischen resonatoren bestehendes elektromechanisches filter
US5740595A (en) * 1989-09-21 1998-04-21 Nihon Musen Kabushiki Kaisha Composite longitudinal vibration mechanical filter's method of manufacturing including undesired vibration absorber

Also Published As

Publication number Publication date
AU465093B2 (en) 1975-09-18
FR2108668A5 (xx) 1972-05-19
AT321366B (de) 1975-03-25
CA956372A (en) 1974-10-15
DE2048125A1 (de) 1972-04-06
DE2047899A1 (de) 1972-04-06
FR2108670A5 (xx) 1972-05-19
CH525588A (de) 1972-07-15
NL7113314A (xx) 1972-04-04
CH529476A (de) 1972-10-15
DE2047899C3 (de) 1975-07-24
BE773271A (fr) 1972-03-29
DE2048162A1 (de) 1972-04-06
AT311424B (de) 1973-11-12
DE2048162B2 (de) 1976-07-08
US3823470A (en) 1974-07-16
AU3408471A (en) 1973-04-05
BE773326A (fr) 1972-03-30
DE2048125B2 (de) 1975-10-30
CA965162A (en) 1975-03-25
DE2047899B2 (de) 1974-12-19
AU3399271A (en) 1973-04-05
NL7113373A (xx) 1972-04-05
GB1330215A (en) 1973-09-12
SE376342B (xx) 1975-05-12
SE362758B (xx) 1973-12-17
GB1365386A (en) 1974-09-04

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