US 3769531 A
The present invention concerns means for generating periodical mechanical vibrations by means of electric energy and deals with a greatly simplified and efficacious swing system which produces mechanical vibratory movements, which system dispenses with any active elements or components except for an energy or current source or cell, the energy losses produced by ohmic resistances in the system being reduced to a minimum and resulting in a high degree of efficiency, reliability, and accurate performance.
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Description (OCR text may contain errors)
llnited States Patent [1 1 Ellmch ELECTROSTATIC SYSTEM FOR GENERATING PERIODICAL MECHANICAL VIBRATIONS  Inventor: Franz Elkuch, Schellenberg,
Liechtenstein  Assignee: Etablissemeut Proeor Vaduz,
' Liechtenstein 221 Filed: net. 17, 1911 211 Appl. No.: 209,142
Related'ILS. Application Data  Division of Ser, No. 863,056, Oct. 2, 1969, Pat. No.
 Foreign Application Priority Data Oct. 8, 1968 Switzerland 14948/68  US. Cl. 310/6, 58/23  Int. Cl. H0211 1/00  Field of Search 310/5, 6, 21, 22,
310/37, 25, 31, 32; 318/116; 58/23, 28, 29, 23 MV, 23 TF; 317/250  References Cited UNITED STATES PATENTS 3,652,955 3/1972 Cruger et 310/25 X 3,609,957 10/1971 Emerson et al.. 310/3 X 3,204,133 8/1965 Tschudin 310/22 FOREIGN PATENTS OR APPLICATIONS 922,033 3/1963 Great Britain 310/5 1 Oct. 30, 1973 Primary ExaminerD. F. Duggan Attorney-Werner W. Kleeman  ABSTRACT The present invention concerns means for generating periodical mechanical vibrations by means of electric energy and deals with a'greatly simplified and efficacious swing system which produces mechanical vibratory movements, which system dispenses with any active elements or components except for an energy or current source or cell, the energy losses produced by ohmic resistances in the system being reduced to a minimum and resulting in a high degree of efficiency, reliability, and accurate performance.
5 Claims, 2 Drawing Figures 4- r Y \V i i [ll- II I ELECTROSTATIC SYSTEM FOR GENERATING PERIODICAL MECHANICAL VIBRATIONS CROSS REFERENCE TO RELATED APPLICATION This application is a divisional application of copending'US. Pat. application Ser. No. 863,056, filed Oct. 2, 1969 now U.S. Pat. No. 3,641,373 dated Feb. 8, 1972.
SUMMARY OF THE INVENTION The invention is applicable more generally to the operation and performance of clocks, watches, and similar instruments requiring substantially no surveillance and nevertheless acting dependably and accurately for an extensive length of time.
It is therefore one of the important objects of the invention to provide means resulting in a highly economical and inexpensive vibratory drive system which can be easily adapted to'the clockwork of timepieces and similar instruments, preferably employable in the scientific field, which require precision and exactitude for their operation.
It is another object of the present invention to provide means conductive to a compact and relatively sturdy device for transferring electric energy to a mechanical drive arrangement which includes vibratory motion release and distribution, the vibratory movable elements being very few in number and having a greatly simplified design or configuration.
Yet a further object of the invention is directed to means affording convenient and continuous replacement or replenishment of energy losses to which said device is subject during operation.
,These and other objects and features of the invention ensue from the following detailed specification, reference thereto being made in the attached drawings illustrating one preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING FIG. ll shows an embodiment of the invention having three electrodes, only one of which is movable.
FIG. 2 shows schematically theapplication of the embodiment of FIG. 1 to a ratchet wheel drive.
.DESCRIPTION OF THE PREFERRED EMBODIMENT For achieving a structure capable of performing desired vibrations, a vibrating member comprising a vibrating tongue with a mass must be mounted in a resilient or springy manner and in a fashion which fulfills the specific physical conditions for proper oscillation of a vibrating reed. When such a member vibrates, i.e, when kinetic (velocity) and static (resilient flexure) energies are in reciprocal propagation within the member, there is a certain damping of the vibration due to the losses of energy which are caused in particular by internal and external friction. To maintain the resultant vibration, it becomes necessary to replace any inevitably resulting energy losses.
In FIG. I there is disclosed a device with an arrangement capable of executing vibratory motions for the drive of a clock or timepiece mechanism, which requires good frequency stability. On an elastic or resilient member or tongue 21 is fastened an electrode 20. The other end of tongue 21 is rigidly connected between two insulating blocks 30. Tongue 21 supporting a mass (electrode 20) at its free end, constitutes a vibrating member which can swing back and forth in the direction of arrow 4 when it is excited to do so. For this purpose, the assembly of tongue 21 and electrode 20 is electrically insulated from the remaining parts of the arrangement (as shown), and two outer electrodes 18 and 19 are fixedly attached or held in position by means of two relatively heavier supports or carriers 25 which are fastened on the outer sides of said blocks 30. Said two outer electrodes are also electrically insulated and are located spaced apart from each other and from movable electrode 20.
Supports 25 are electric conductors, so that through connections 7 and 8, electric current (opposed electrical potentials) can be supplied to the outer electrodes from a voltage source or energy cell (not shown) for the charging of these electrodes. Blocks 30 contain or consist of insulation material.
It is obvious from the electrotechnical theory that when movable electrode 20 touches neither electrode 18 nor electrode 19, it is held only electrostatically under the influence of outer electrodes 18 and 19, and is totally insulated from the other parts. The mechanical action of this electrostatic influence on movable electrode 20 will depend upon the electrical charge and the location of the latter at that particular moment, assuming that both the outer electrodes are charged at predetermined potentials.
If movable electrode 20 has, for instance, a negative electrical charge, and, if it comes near outer electrode 18 (which bears a positive potential, as shown), the electric field between these two electrodes will act on them and cause an attraction of the one toward the other, movable electrode 20 being moved counter to the force of elastic tongue 21 toward and up to electrode 18.
As soon as the electrodes closely approach or touch each other, the potential difference (or electrical charge disparity) between these two electrodes is compensated and the electric field disappears rapidly. Electrode 20 now assumes the same polarity as electrode 18 and will be repelled by the latter as long as it touches it or is in proximity thereto. Electrode 20 is then exposed to the action or force of elastically tensioned tongue member 21 and hence can swing back, passing, owing to inertia, beyond its neutral or initial position and approaching outer electrode 19, which, as shown, has a negative polarity. Since electrode 20 now has a positive electrical charge (from preceding contact with electrode 18), the same aforementioned action will occur, but with respect to electrode 19 and with reverse polarities and directions. Subsequently, electrode 20 comes successively and alternately in contact with outer electrode 18 and with outer electrode 19, thereby causing a charge exchange each time, the aforementioned operation and phenomenon repeating itself in each direction.
As is plain from FIG. 1, the vibrating member formed of tongue 21 and electrode 20 is totally insulated from the rest of the arrangement; it is clearly apparent, therefore, considering the laws of the electrostatic theory, that the potential which this member 20, 21 would theoretically exhibit as compared with the outside (if it were possible to measure it) will undergo certain fluctuations in the course of the movement which takes electrode 20 from one of the outer electrodes to the opposite one, these fluctuations in theoretical potential being due to the fact that the electric charge itself cannot vary as long as electrode remains completely insulated. This theoretical potential will undergo the greatest fluctuation at the outermost parts of the movement, i.e., just at the moment when electrode 20 is leaving an outer electrode or is about to touch one. It is also at those points that the mechanical force, which is electrostatic in origin, acting upon electrode 20, will be by far the greatest. During the whole remainder of the movement, the mechanical force of electrostatic origin will be much weaker and practically negligible.
This distinguishes the system according to FIGS. 1 and 2 from a system in which, e.g., by means of a capacitance condenser of appreciable capacity capacitance connected between electrode 20'and a point of fixed potential, the potential of electrode 20 would remain practically the same during the entire movement of that electrode. The'result would be that the electric charge carried by electrode 20 would undergo changes.
' In such a case, as a matter of fact, at the'moment when electrode 20 moves close to oneor the other of the outer electrodes (18 or 19 which would cause it to undergo fluctuations of potential if the latter were not sustained from outside, e.g., by means of the said condenser), it would,- if its potential is sustained, acquire or loseelectric charges precisely intended to prevent said potential fluctuations. The consequence of this gain or loss of electric charge(in such a case of operation with sustained potential) would be to extend the terminal portions beginning and ending-of the movement, upon which'appre'ciable mechanical forces of electrostatic origin act. v
That feature of the system shown in FIGS. land 2 according to which the intermediate vibrating member 21, 20 is totally insulated from the rest of the arrangement appears to be very important one, for it tends to make as short as possible those periods of time during which the mechanicallforces of electrostatic origin act upon the vibrating member to maintainv its oscillation.
lt will be noted that forces act on the vibrating mass in either direction of movement thereof, and during the brief contact of electrodes 18, 20 and 19, 20, only a relatively small compensating current flows, which is independent of the resistance of the circuit including electrode 18, support of electrode 18, terminal 7, voltage source, terminal 8, support 25 of electrode 19, and electrode 19. The voltage source must merely replenish the electrons intermittently absorbed by electrode 20 from electrode 19, which it transfers to electrode 1 8, Therefore, the efficiency of this device is extremely high and dependable.
Contact points 22, 23, and 24, of a known conductive metal or material resistant to burning down or melting, are arranged on the end faces of the respective electrodes. They render it possible that when using a voltage source of 1,000 volts, for example, the electrodes need not approach each other completely for the charge exchange or' load compensation, because at a sufficiently minute or small distance between the contact points, a spark arcs already over which suffices for charge compensation. In this way, the harmonic vibratory movement of tongue 21 with electrode 20 is not disturbed by any impact of the electrodes on each other.
It is known from the theory of vibrating reeds that with such a vibrating device, contrary to what happens with an oscillator device of the spiral-balance type, for example, a mechanical action for maintenance of the oscillation, applied at the end of the path of movement, is in any case not more unfavorable than a mechanical action for maintaining the oscillation applied in mid course/As long as the mechanical maintenance action applied to a vibrating reed at the end of the movement remains relatively sudden and retains a magnitude corresponding merely to the compensation of the energy losses which would otherwise damp the vibration movement, it is known that according to the vibrating reed theory, the vibration will remain a harmonic vibratory movement (having a frequency determined by the physical parameters of the vibrating reed).
FIG. 2 shows that for the partial decoupling of the vibration energy, a transducer may be inserted in the-circuit, which transforms the current surges occurring during a charge reversal into an alternating current voltage, which can be tapped atthe terminals of the secondary winding of the transformer or transducer. At the resilient tongue, a pawl 55 may be arranged which engages in the asymmetrical ratchetteeth 56 of a gear 57, the latter being advanced by one tooth during each vibratory movement.
Since for generating a force necessary for vibrating the" electrodes, a voltage source of relatively high voltage, say, of at least volts, is necessary, an isotropic generator is advantageously employed. Such voltage cells or sources can be accommodated within 'a'minimum of space and yet furnish a terminal voltage of more than 1,000 volts.
The electric circuit of the above-described aggregates or arrangements is very simple, and any necessary changes of direction of the electric field are effectuated automatically by the movements of the intermediate electrode. The great advantage of this arrrangement is that a vibration generator can be conveniently accommodated at greatly reduced dimensions, yet operates with a very high efficiency and which is suitable for installation in timing instruments, clockworks, and the like. i
It will be seen from the aforesaid disclosure that there has been created according to this invention a very compact and highly efficient vibratory system, which lends itself to a great variety of applications-in the'instrument field and may be modified or altered according to the purpose intended. 1
What is claimed is:
1. A system for generating periodical mechanical oscillations with substantially high frequency stability for the drive of a timepiece and like instrument, comprising three electrode means arranged in spaced confronting relationship with regard to one another and at a predetermined distance from one another in inoperacharge carried thereby when said intermediate electrode means moves from one to the other of the outer electrodes, a direct current power source, and conductor means for respectively connecting said outer electrodes with different polarities of said direct currentpower source.
2. The system as defined in claim 1, further including transmission means operatively connected with said intermediate electrode means, said transmission means incorporating a pawl-shaped member connected with said vibrating member, a ratchet wheel which can be actuated by said pawl-shaped member in position position of said electrode means, so that the resultant mechanical oscillation energy of the vibrating member imparts rotational movement to said ratchet wheel through the agency of said pawl-shaped member.
3. The system as defined in claim 1, wherein said three electrode means incorporate means for precluding any disturbing effect upon the vibratory movement of the vibrating member due to possible impact of said electrode means against one another.
4. A system for generating periodical mechanical oscillations with substantially high frequency stability for the drive of a timepiece and like instrument, comprising a pair of outer electrode means, resilient tongue means disposed intermediate said pair of outer electrode means, said resilient tongue means incorporating means defining an intermediate electrode means coopcrating with said pair of outer electrode means, said pair of outer electrode means and said intermediate electrode means being disposed in spaced confonting relationship from one another in inoperative position of said electrode means, with said intermediate electrode means being carried by said resilient tongue means to perform an oscillatory movement which successively at least approaches one and then the other of said outer electrode means, means for insulating said intermediate electrode means such that said intermediate electrode means possesses a substantially constant charge during movement from one to the other of said outer electrode means, a direct current-power source having different poles, and means for respectively connecting said outer electrodes with different poles of said direct current-power source.
5. The system as defined in claim 4, wherein said means of said resilient tongue means defining said intermediate electrode means is a separate electrode member mounted upon said resilient tongue means.