US2468538A

US2468538A - Ultra high frequency vibrator

Info

Publication number: US2468538A
Application number: US640249A
Authority: US
Inventors: Benioff Hugo
Original assignee: Submarine Signal Co
Current assignee: Submarine Signal Co
Priority date: 1946-01-10
Filing date: 1946-01-10
Publication date: 1949-04-26
Anticipated expiration: 1966-04-26

Description

April26, 1949. H. BENIOFF 2,463,538

ULTRA HIGH FREQUENCY VIBRATOR Filed Jan. 10, 1946 2 Sheets-Shet 1 INVENTOR. HUGO BENIOFF April 26, 1949. H. BENIOFF 2,468,533

ULTRA HIGH FREQUENCY VIBRATOR Filed Jan. 10, 1946 I 2 Sheets-Sheet 2 INVENTOR. HUGO BENIOFF HIS ATTORNEY Patented Apr. 26, 1949 UNITED1 STATE ULTRA HIGH FREQUENCY VIBRATOR Hugo Benio'ff, Pasadena, Calif., assignor, by mesne assignments, to. Submarine Signal Company, Boston, Mass, acorporation of Delaware Application January 10, 1946, Serial No. 640,249

10 Claims.

The present invention relates to an ultra high frequency vibrator of the type disclosed in my copending application, Serial No. 606,498, filed July 23, 1945, and relates more particularly to improvements over the apparatus therein disclosed. One of the principal advantages inthe present constructionis that. in the present device, the insulating oil surrounding the oscillating element is sealed permanently rather than being sealed by a removable seal like a packing glandor a.rubber gasket. The whole apparatus is placed under vacuum before filling to outgas the whole structure. The oil is heated to 100C. under vacuum and their is permitted to fill the chamber to full atmospheric pressure, thus en tirely exhausting the oil of air and gas.

rials of liquids or solids which are placed in a container which fits into the top of the device in a liquid cup1ing.rnedium covering the electrode of the crystal but separated from the insulating oil. The apparatus may be used not only for laboratory work but also for industrial and commercial purposes.

Further advantages and merits of the present invention will be more'fully described in the specification below in connection with the drawings showing an embodiment thereof, in which Fig. 1 shows a general vertical sectional view through the apparatus taken on the line ll of Fig. 4; Fig. 2 shows a plan view as seen from the top of Fig. 1; Fig. 3 shows a section taken on the line 33 of Fig. 1; and Fig. 4 shows a view in vertical elevation of the device.

In the arrangement-illustrated by the figures the liquid vibrator, as a whole, is supported by a flange 9 on the inner side of which is attached a flange 5 by means of a soft solder weld as indicated at 30. The collar 5 is provided with an inwardly extending shoulder or'supporting ring 3| to which is attached a plate 32 by means of a series of screws 33 clamping the plate 32 to the shoulder 3| between which is a sealing gasket l8. The plate 32 has attached 'on its under side a downwardly extending cylindrical flange-or collar 34 to which is attached in turn a heat resistas will not crack underchanges in temperature.

fFirst a band of silver is fired o the ends of the means of soft solder of a suitable type.

ing glass tube 12 or such other type of glass tube 04' glass tube which is then soldered by means of .roft' solder to' the collar 34 at the top and the collar 34' at *the'bottom. Fitting over the ends of the glass tube l2 are small. end fitting rings l0. and I0 which support the glass tube and to 'which'the collars 34' at the top and 34' at thebottom are also soldered. The collar 34' at the base (Fig. 1) extends from the supporting base 35 on which also the ring |0- is supported. The supporting base 35 is-formed with a cylindrical shell 36' which extends upwardlyv and supports the quartz crystal 368.- The cylindrical shell .36 forming the chamber 36 is provided at the top with a narrow neck portion 31 and an end shoulder or corner 38 extending all the way around the neck 31 serving as a seal for the crystal 368. The crystal is retained in the shoulder 38 by layer of silver is burned on the lower face of the crystal which serves as the lower electrode 39 and a base for soldering at the edge. The crystal 388 is formed of quartz or other suitable piezoelectric mate-rial with electrode 39 on the bottom surface of the crystal and an electrode 40- which is a thin metallic diaphragm separated from the top surface of the crystal by a thin oil film as will be explained later. This thin diaphragm forms an acoustic window whereby'the vibrations are transmitted to the liquid chamber above it. The base member 35 mentioned previously is provided with air vents ll extending from the outside of the device to the inside chamber 36. A bellows element 4| is attached to-the bottom of the base 35 by suitable means such as soldering and a communicating-passage 42 is provided through the base 35 to the'chamber formed with a glass tube I2 on the outside and the cylindrical shell 36' on the inside which supports the piezoelectric crystal. This chamber 43 and the inside of the bellows are filled with insulating oil mentioned before which has been heated'and cooled under vacuum for sufficient time to withdraw all of the gases contained in the oil. The oil of the chamber 43 surrounds the crystal 363 on its sides and forms thev film on top of the crystal between the top crystal surface and the metal electrode and dia phragm 40, The upper part of the chamber 43 is separated from the liquid into which the sample to be vibrated is placed by the cylinder 44 positioned'concentrically within the glass tube. The diaphragm 40 is attached by proper welding or otherwise to the bottom of the cylinder 44 which is provided with a rounded flange on its base.

First a 'ratus.

3 The diaphragm 40 is preferably very thin so as to permit vibrations to pass through it unimpeded and may be of Monel metal or some similar eleg ment. The tube 44 may be of copper and of comparatively thicker dimensions as this element need not enter into the vibrationand provldesa path of high heat conductivity to carry heat away i from the crystal. The top of the tube 44 restsin a shoulder in the plate 32 and has also an upwardly extending cylindrical portion 45, by means of which a seal is formed at the top of the chamber 43 with the downward flange 49 of the ring 48. In this construction the sleeve or collar 2 welded to the plate 32 is positioned concentrically with the various tubes and cylinders of the appa- The sleeve 2 is threaded at its top to receive a cap 6 provided with an inwardly'exe tending flange and shoulder 41 on which the container orvessel 53 'is placed. The sleeve 2 is recessed at its inner top edge to form a seat for the flanged member 48 which is welded to the sleeve 2. The member 48 has integrally formed with it the neck 49 abutting the collar 45.

Assembly is complete beiore the oil is introduced aotherwise the oil would be exposed to air which would greatly increase its tendency to waves which would permit electrical breakdowns and decrease the efliciency of acoustic coupling.

I6 is a valve for evacuating and filling the chamber.

It should be noted that surrounding the quartz crystal 38B is a micaring 3" which is supported by meansof three glass rods I! which lit in recesses at the top in theiunder side of the plate 32 and at the bottom in the base 35. The length of the rods is such as to leavea small spaceat thetop so as not to put pressure on the glass rods. Within the cylinder 44, which is closed at the bottom by the diaphragm 40 serving as an electrode for the quartz crystal 368, there is a liquidbath .52 which serves as an acoustic or V vibratory coupling medium between the vibrations centrically positionedwith respect to said tube forming a portion of the inner wall of said chamher, said container having a diaphragm sealed to the bottom thereol.', said diaphragm extending over the front surface of sald rystal with an oil film between. the .crystal and saidndiaphragm, meanseffecting a permanent seal atboth the bottom and top of said'chamber andinsulating oil substantially free of gases extending throughout saidchamber. I

' 2; An ultra high frequency vibrator comprising a piezoelectric crystal; having a thin peripheral flange. an enclosed cylinder having a seat formed.

around the. periphery atone end to which the flange of the crystalis sealed, a heatreslstant insulating tube surrounding and concentric with said crystal and cylinderproviding the outer walls of an insulating oil chamber, a container concentrically positioned with respect tosaid tube forming a portion of the'inner wall of said chamber, said container having adiaphragrn sealed to the bottom thereof, said diaphragmextending over the front surface of said crystal with an oil 3 film between. the crystaland said diaphragm,

form bubbles under the action of intense sound means efiecting a. permanent seal at both the 7 bottom and top of said chamber and insulating oil substantially free of gases extending throughout said chamber and cooling means extending into said chamber. I v i 3. An ultra high frequency vibrator comprising a piezoelectric crystal having a thin peripheral r flange, an enclosedcylinder having a seat formed around .the periphery at one end to which the flange of the crystal is sealed by soft solder applied to burned on silver, a heat resistant in- I sulating tube surrounding and concentric with said crystal and cylinder providing the outerwalls of an insulating oil chamber, a container concentrically positioned with respect to said; tube produced by the crystal and the sample container 53 the bottom of which is immersed in thebath. The sample container 53 is seated in the holein the cap 6 and extends well down within the cylinder 44. The substance to be treated is placed within the container 53 the bottom of which is covered with a very thin diaphragm 54. The sample may be a liquid or whatever is desired to be treated with the vibrations produced b the device.

Electrical energy is conducted to the crystal in the manner similar to that in my copending application mentioned above. The glass tube and rods together with the liquid in the chamber 43 act as insulating elements between the two electrodes 39 and 40. Electrical energy is conducted tothe electrode 39 through the'cylinder 36', the base 35 and the outside protecting cover 55; The upperelectrode 40 is gro1mded to the casing or supporting ring 8. The device is employed in the same manner as described in my above mentioned said crystal and cylinder providing the outer walls i of an insulating oil chamber, a container conforming a portion of the inner wall of said chamber, said container having a, diaphragm sealed to the bottom thereof, said diaphragm extending over the front surface of said crystal with an oil film between the crystal and said diaphr'agm, means effecting a permanent seal at 1 both the bottom and top of said chamber comprising a thin flange extending upwardly from the top of said container, a collar concentrically positioned with respect tosaid container and forming a permanent seal at the outer side of said chamber, said collar having a seating recess at the top thereof, a ring having a downwardly extending flange positioned to adjoin the upwardly extending flange of said container. said ring being sealed in said seat and at the junction of the flange with the flange of the container.

4. An ultra high frequency vibrator comprising a piezoelectric quartz crystal having a thin flange at its peripheral edge, a cylinder closed at one end and exposed to the air havinga thin section a at its open end, means sealing said crystal at its thin section to said cylindenmeans providing a sealed chamber having its axis parallel with the vibrational axis of said crystal and extending above and below the same,coollng meansprovided atthe bottom of saidchamber, said chamber having an acousticwindow extending over the upper surface of saidgcrystal and means forming aliquid bath over said window and on the inner side of said chamber a mica insulating ring surrounding said crystal and positioned over saidflange, insulating, means supporting said ring within said'chamber.

5.An ultra high frequency vibrator comprising a piezoelectric crystal having a' relatively 6 P system, a second chamber outside of said sealed chamber and also having said diaphragm as a wall thereof, and an acoustic coupling medium window as anotherwall thereof, a substantially gas-free insulating oil filling said chamber and thereby covering a surface of said crystal, said window being disposed to extend over said surface separated therefrom only by a film of said oil. v 6. An ultra high frequency vibrator comprising a hermetically sealed chamber having a diaphragm as a wall member thereof, a substantially gas-free insulating oil filling said chamber, and

a piezoelectric crystal positioned in such 9101- imity to said diaphra m wall that said diaphragm wall may serve as onev electrode of a ystal vibrating system.

7. An ultra high frequency vibrator comprising a hermetically sealed chamber having a diaphragm as a wall member thereof, a substantially gas-free insulating oil filling said chamber, a piezoelectric crystal positioned in such proximity to said diaphragm wall that said diaphragm wall may serve as one electrode of a crystal vibrating system, a second electrode attached to a surface of said crystal, and means providing electrical connections to said second electrode and to said diaphragm.

8. An ultra high frequency vibrator comprising ,a hermetically sealed chamber having a diaphragm as a wall member thereof, a substantially gas-free insulating oil filling said chamber, a piezoelectric crystal positioned in such proximity to said diaphragm wall that said diaphragm wall may serve as one electrode of a crystal vibrating in said second chamber, whereby acoustic energy is coupled from said crystal to said medium through said diaphragm.

9. An ultra high frequency vibrator comprising a hermetically sealed chamber having a diaphragm as a wall member thereof, a'substantially gas-free insulating oil filling said chamber, a

piezoelectric crystal positioned in such proximity to said diaphragm wall that said diaphragm wall may serve as one electrode of a crystal vibrating system, said chamber extending away from said diaphragm reentrantly as a cup with said diaphragm in the bottom thereof, and an acoustic coupling medium disposed in said 'cup;

10, An ultra high frequency vibrator comprising a hermetically sealed chamber having a diaphragm as avwall memberthereof, a substantially gas-free insulating oil filling said chamber, a piezoelectric crystal positioned in such proximity to said diaphragm wall that said diaphragm wall form of a bellows.

may serve as one electrode of a crystal vibrating system, a portion of said chamber being in the HUGO BINIOI'P.

nnranancns crrl-m The following references are of record in the ilie of this patent:

UNITED STATES PATENTS