Patent Publication Number: US-3876891-A

Title: Mounting for rod-like crystal oscillators

Description:
United States Patent [191 11] 3,876,891 Schubotz 5] Apr. 8, 1975 [54] MOUNTING FOR ROD-LIKE CRYSTAL 3,054,915 9/1962 l-lou&#39;ck 310/91 OSCILLATORS 3,185,870 5/1965 Stoddard 310/9.4 3,221,189 11/1965 Brandt et a1. BIO/9.1 [76] Inventor; Peter Schubotz,Eberwurzstrasse 89,  
  8000 Munich 45, Germany Primary Examiner-Mark O. Budd [22] Flled&#39; 1973 Attorney, Agent, or Firm-Hill, Gross, Simpson, Van [21] Appl. No.: 325,363 Santen, Steadman, Chiara &amp; Simpson Related US. Application Data [63] Continuation-impart of Ser. No. 171,484, Aug. 13,  
 I971. [57] ABSTRACT [30] Foreign Application Priority Data Piezoelectric crystal rod oscillator is supported within Aug. 14. 1970 Germany 2040614 a musing by and between electrical chductrs which are attached rigidly in electrically isolated manner 52 us. Cl. .1 310/94 Within Opposite n p rt ns of the housing such that 511 im. Cl H04r 17/00 the oscillator is maintained mechanically stable [58] Field of Search 310/82, 9.1-9.4, letie&#34; Within the hellsihg&#39; This is effeeed a manner 310/9], 98 enabling use as a closure plate for the housing a standardized transistor housing base plate.  
 [56] References Cited o UNITED STATES PATENTS 1 Claim, 5 Drawing Figures 2,953,696 9/1960 Ruggles 310/9.l  
 MOUNTING FOR ROD-LIKE CRYSTAL OSCILLATORS CROSS REFERFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 171,484, filed Aug. 13,-1971. I  
  This invention relates to mounting means for rod-like crystal oscillators, and is more particularly concerned with the mounting of piezoelectric crystal rod oscillators in stable relation within compact housings.  
  Substantial manufacturing advantage and economy, can be attained by utilizing electro-technical compo-.-  
 nents which have attained definitive standards in the industry. Among such components are transistor housing base plates of which dimensions have been standardized. Among similar and related uses for such standardized base plates is the closure of piezoelectric crystal rod oscillator housings. This entails the problem, by way of example, that due to the relatively small dimensions of such base plates it is difficult to maintain the crystal oscillator mechanically stable with its axis oriented perpendicularly to the base plate, and more particularly of attaining a suitable mounting which will lend itself readily to advantageous mass production methods of manufacture.  
  It is, accordingly, an important object of the present invention&#39;to solve the problem of providing a mounting for rod-like crystal oscillators with the use of available, standardized transistor housing base plates or disks.  
  Another object of the invention is to provide a new and improved mounting for piezoelectric crystal rod oscillators.  
  A further object of the invention is to provide a new and improved rod oscillator mounting in thoroughly stable&#39; relation within a housing.  
  Still another object of the invention is to provide a new and improved mounting of a piezoelectric crystal rod oscillator in a housing in an advantageous, low cost, efficient, reliable manner which will lend itself readily to mass production methods of manufacture.  
  Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in&#39; conjunction with the accompanying drawing, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:  
  FIG. I is a vertical sectional elevational detail view on a substantially enlarged scale of one preferred embodiment of the invention;  
  FIG. 2 isatransvrse sectional detail view taken substantially along the line IIII of FIG. 1;  
  FIG. 3 is a vertical sectional view illustrating a modified construction embodying the invention;  
  FIG. 4 is a transverse sectional detail view taken substantially along the line IVIV of FIG. 3; and  
  FIG. 5 is a horizontal sectional view taken generally along the line V-V of FIG. 2.  
  Referring to FIGS. 1, 2 and 5 a suitable length bar or rod-like piezoelectric oscillator crystal 1, such as quartz, is suspended for oscillation by means of fine conductor wire filament suspensors 2 by and between electrical conductor post means desirably in the form of suitable gauge stibstantially coextensive parallel extensions of wire conductors and of sufficient resistance to deformation to serve the intended function. As will be observed, one of the suspensors2 extends to and between the oscillator 1 and the posts 3 adjacently spaced fromeach opposite end of the. oscillator, extending transversely to the axes of the oscillator and the posts and each soldered fixedly on one hand to an electrode surface of the oscillator and on the other hand to the respective postuwith the respectiveendsof the pairs of the suspensors attached toth e-oscillator beingon re; spectively. opposite sides of the oscillator so as&#39;t o enable thedesired oscillating action when the oscillator is excited by electrical potential through the posts and the suspensors.  
  Mounting of the posts 3 in a manner to implement not only their vibrator-supporting function but also their electrical conductor function and enabling then to serve as electrical connectors with circuitry of associated apparatus, a base disk structure 4 is provided through which the conductor post wires 3 extend and are rigidly secured in electrically isolated, insulated manner. In a desirable form, attaining advantageous economy in construction and manufacture, the base disk 4 comprises a standardized commercially available transistor housing bottom or base plate disk adapted to the instant purpose. The mounting and relationship of the elements is such that the vibrator l is disposed&#39;perpendicular to and with its adjacent end spaced from the base disk 4. 3  
  A mechanically substantially rigid frame relationship including the posts 3 and the base disk 4 is provided by the aid of means rigidly connecting the end portions of the posts 3 opposite the base 4 and extending freely beyond the end of the vibrator l remote from the base. To this end,such end portions extend fixedly through suitablerespective aperturesS in a disk-6 of a suitable form-stable dielectric material such that the posts will be electrically insulated from each other.  
  To facilitate miniaturization and economical manufacture, the disk 6 is desirably punched from a thin laminate and comprises an insulating core 6a (FIG. 5) and bilateral metallic facings 7. Thereby production of disks 6 is greatly facilitated because hundreds of pieces can be derived from a blank sheet or thin plate of the material. The metallic facings greatly facilitate the soldering operation by providing excellent soldered anchorage of the posts 3 at each metallized face of the disk 6. In order to effect electrical isolation of the posts 3 from one another and avoid any electrical connection therebetween by way of the metallic facings 7, areas of the metallic facings between the anchorage areas surrounding the perforations&#39;S are stripped from the insulating core. For example, generally semi-circular areas 8 may be thus stripped about each of the anchorage areas, and with the stripped areas running out at the edges of the disk so that&#34; there is no electrically conductive ridge or connection between the solder-anchorage areas.  
  In addition, means are providedon the frame disk 6 for nonelectrical stabilizing cooperation with enclosing housing meansfor the oscillator. To this end, the disk is outside of the anchorage areas provided with a plurality, such as three, suitably circumferentially spaced peripheral radially extending spacer projections or lugs 9 adapted to engage firmly with the inner wall of an elongated generally cup-shaped shroud or cap shell 10 which may be constructed asa drawn metal member of an inside diameter to clear the perimeter of the disk 6 and of a length to clear the ends of the posts 3 at its closed end while its open end is engaged and secured within&#39;a rabbet 11 provided in the perimeter of the base disk 4. The,lugs.9 are so arranged and dimensioned that uponinsertion of the :vibrator frame into the cap 10, the lugs are slightly deformably compressed and efficiently *center andfirmly ,hold the frame structure against vibrating relative to&#39; the cap so that undesirable changes in capacitance may notltake place between the surfaces of the. vibrator l and the housing wall. Refering&#39;to FIGS. 3 and4, a slightly modified structure is depic ted in which an especially long bar or rodnecting wires 3. The additional fixing of the free ends of theframe pins 12 is accomplished in the same manner as. in FIG. 1 where the frame employs the connecting wires themselves for supporting the crystal rod-like oscillator, namely, electrically conductive filament suspensors 2 connect the oscillator 1&#39; to the post pins 12, and the framehead disk 6&#39; rigidly connects the free end portions of the post pins together and effects a lug-tight stabilizing engagement with the inner end portion of the housingcup In both forms of the invention highly advantageous mechanical stability in the mounting for the oscillator member is, attained not ,onlybecause the supporting rods therefor are held in fixed spaced relation adjacent to each opposite end of the oscillator, but also because the supporting-rod spacers are fixedly held against displacement, movement relative to the housing from whatever cause, whether endwise thrusts or shocks or transverse shocks or vibrations. Additionally, the assembly is; substantially insensitive to fluctuations in temperature,.not only because there is relatively similar coefficient of expansion of at least the housing cap shell member and the metal-faced frame head disk, but also because. the head disk is peripherally spaced from the housing shell except for. the small areas of lug contact which are sufficiently resiliently yieldable relative to the housingshell to maintain firm contact therewith even in extremesof temperature variation.  
  The mounting is, inparticular, insensitive to temperature fluctuations according to another feature of the invention, even if such fluctuations reach an extreme level, The metal layers 7 on each side of the thin laminate core 6a of the disk 6 and the metal cap shell 10 have the same, or nearly the same thermal coefficient of expansion and&#39;thus expand and contract approximately the same extent. The dimensioning of the metallie facing 7 and the disk core 6a is such that the temperature response of the metallic facing 7 is forced upon the thin laminate so that the laminate expands or contracts with the metallic facings even though it has a different thermal coefficient. The thickness of the thin laminate core 6a depends on the diameter of the cap shell 10. The thickness should be selected such that the disk has a sufficient thickness in relation to its diameter for sufficient stiffness and the like. For example, for a 5 mm disk, a 0.3 mm thickness is sufficient. The expansion and contraction of the bilateral metal coatings 7 which force expansion and contraction of the thin laminate core 6a may be realized by utilizing the teachings in the book Introduction to Printed Circuits, by Robert L Swiggett, published by John F. Rider, Publisher, Inc. New York, Library of Congress Card Catalog Number 56-11841. Reference may be taken to page 25, Table I of that publication for suitable layer techniques. According to the present invention, however, the laminate is metallized on both sides. In a particular construction, such as exemplified above, a copper layer was provided on each side and reinforced by galvanic deposition to a thickness of approximately 0.1 mm. As will be apparent from the foregoing, all of the stated objects of the invention, among others, are attained to excellent advantage.  
  Although I have described my invention by reference to specific illustrative embodiments, many changes and modifications of my invention may become apparent to those skilled in the art without departing from the spirit and scope thereof. I therefore intend to include within the patent warranted hereon all of the changes and modifications as may reasonably and properly be included within the scope of my contribution to the art.  
 I claim:  
  1. Mounting means for rod-like oscillators of the type wherein a housing base plate has connecting wires extending therethrough, an oscillator rod is arranged parallel with and between post extensions from the wires and connected to the post extensions by means of wire filament suspensors extending transversely to the axis of the rod and soldered to the electrode surfaces of the rod and to the post extensions, a drawn metal substantially cup-shaped housing shell enveloping the rod and post extensions is connected to the base plate, and a disc having perforations for receiving the free ends of the post extensions includes circumferentially spaced projections on the perimeter thereof engaging the housing shell and maintaining the remainder of the perimeter of said disc in spaced relation to said housing shell, the improvement therein wherein:  
 said disc comprises a punched thin laminate including an insulating core and bilateral metallic facings on said core;  
 said metallic facings and the housing shell having like thermal coefficients of expansion and thus similarly respond to temperature change, the dimensioning of the metallic facings and the disc core being such that the temperature response of the metallic facings is forced upon the thin laminate so that the laminate expands or contracts with the metallic facings even though it has a different thermal coefficient; and  
 each of said metallic facings including a pair of armate gaps concentric&#39;with respective ones of said perforations.