US2752775A - Device for measuring the error of a clock movement - Google Patents

Description

M, HETZEL July 3, 1956 DEVICE FOR MEASURING THE ERROR OF A CLOCK MOVEMENT Filed March 13, 1955 2 Sheets-Sheet l ngtopw Illllll IIIII @Smm @EWS

. [iii July 3, 1956 M. HETZL 2,752,775

DEVICE FOR MEASURING Tl- IE ERROR OF' A CLOCK MOVEMENT Filed March 13, 1953 2 Sheets-Sheet 2 4lRuff? H11 [FHI ,49,2

DEVICE FOR MEASURING THE ERRUR F A CLCK MOVEll/[ENT Max Heizel, Bienne, Switzerland, assigner to Bulova Watch Company Inc. New York, Bienne `llranch, Bienne, Switzerland, a joint-stock company Application March 13, 1953, Serial No. 342,168 Claims priority, application Switzerland May 19, 1952 2 Claims. (Cl. 736) This invention relates to error measuring devices, and more particularly to a device for measuring the error of the movement of a watch or clock.

lt is an object of this invention to reduce the time required for ascertaining the amount by which the watch is fast or slow.

It is another object of this invention to provide a device of the kind described which can be operated by an unskilled person.

lt is a further object of this invention to provide a device of the kind described which allows of taking an error in a relatively large interval about the value zero.

lt is still another object of this invention to avoid certain drawbacks of hitherto known devices designed to meet the same requirements.

The device according to the present invention comprises a first signalling device controlled by the electrical signal derived from the vibrating escapement of the movement, a second signalling device yielding a comparison vibration, a delay arrangement supplying the signal generated by the iirst signalling device to the second signalling device so as to reset the same in its initial condition, and at least one testing and indicating device controlled by the two signalling devices.

ln the drawings aiixed to this specification and forming part thereof an embodiment of this invention is illustrated diagrammatically by way of example.

In the drawings:

Fig. l is a block diagram of a device according to the present invention, and

Fig. 2 is a wiring diagram of parts of the device shown in Fig. l.

Referring to the drawings and rst to Fig. l, the device comprises parts serving to derive a controlling signal in dependence on the vibration of the escapement of the watch to be examined. These parts are denoted in the block diagram shown in Fig. l with 1, 2, 3, and d, respectively. 1 is an amplifier, to the input of which a voltage is supplied by a microphone which is placed above and in contact with the watch to be examined, the voltage corresponding essentially to the beats produced by the watch in the disengagement, by the striking of the escapement lever against the horn and by the hitting of the resting face by the lever wheel. These signals, amplified by the amplifier 1, are supplied to a converging device 2 generating a rectangular impulse of the signal supplied by the microphone S and at the same time rendering ineffective the two subsequent impulses. The impulse supplied by the output of the converting device 2 is fed to a non-independent symmetrical trigger arrangement 3 (Scaler), which changes the triggering conditions thereof under the influence of each single impulse. Thus, a positive impulse is fed to the oscillating device 4 only at every other impulse supplied by the converting device 2 which can bias the oscillating device so that the latter Supplies a very short rectangular impulse having a duration of about 4 microseconds.

2,752,775 Patented July 3, 1956 "ice The device further includes a plurality of non-independent symmetrical trigger arrangements KZ-Kn, only the arrangements KZ, Kx and Kn being shown in the drawings. The first trigger arrangement KZ is connected to an oscillator 6 which is stabilized at a relatively high frequency by a mechanical oscillating element such as a crystal or a tuning fork (not shown).

T he non-independent symmetrical trigger arrangements or devices Kx-Kn are connected with the testing arrangements Px -Pn, respectively. All trigger arrangement KI-Kn are connected by a common conductor 7 and a delay member 8 to the output of the oscillating device 1i. Furthermore all testing arrangements Px-Pn are connected by means of a common conductor 9 to the output of the oscillating device 4. The testing arrangements or devices are further connected to indicating arrangements Ax-An, respectively, to which are connected indicating lamps Lx-LnZ, respectively, two lamps Lnl and LnZ being connected to the indicating arrangement An, The indicating arrangement An controls a controlling arrangement 10 for the indicating lamps Lx- Lit-1.

Referring now to Fig. 2, the non-independent trigger arrangements KI, Kr and Kn, the testing arrangements Px and Pn, the indicating arrangements Ax and An together with the associated indicating lamps Lx and Lnl, L/LZ, and the controlling arrangement 16 are shown. The trigger arrangements (not shown) connected between the trigger arrangements Kx and Kn and associated with testing arrangements (not shown) associated with indicating arrangements (not shown) associated with indicating lamps such as Lx-I-l and Lui-1 (shown in Fig. l) are designed in the same manner as the trigger arrangements Kx and Kn. The associated testing arrangements (not shown) are designed like the testing arrangements Px and Pn, the indicating arrangements (not shown) connected therewith are connected in the same manner as the indicating arrangement Ax.

The trigger arrangements Kl, Kx, and Kn are designed in the same manner and corresponding parts thereof are denoted by the same reference numerals. The same applies to the testing arrangements Px and Pn and to the indicating arrangements Ax and An.

The trigger arrangements are equipped with double triodes 20, the wiring diagram of which is exactly symmetrical. The anodes of the triodes are connected to the positive terminal of D. C. sources (not shown) through anode resistors 11 and to the grids of the other triodes through resistors 12 and capacitors 13, respectively. The grids of the triodes are connected to resistors 14 which are connected to the negative terminal through a common resistor 15. In the following description it is assumed that in the normal condition (rest position) of the trigger arrangements the left-hand triodes of the tubes 20 are conductive. In the normal condition the Cathodes of the double triodes are assumed to be grounded. Under these assumptions the anode of the left-hand triode has a low potential, whereas the anode of the right-hand triode is at a .high potential. Accordingly the potential of the grid of the left-hand triode is at 0 volts, so that this triode is maintained conductive, while the potential of the grid of the right-hand triode is so low that this triode is completely blocked. The junction of the resistors 14 and the resistor 15 is connected by means of a condenser 16 with the preceding trigger arrangement, more particularly in the embodiment shown in the drawings with the lefthand anode of the same. If a negative impulse is applied over the condenser 16, the left-hand triode suddenly becomes non-conductive too, and in consequence thereof the potential of its anode increases rapidly. This increase of potential is transferred by means of the capacitor 13 without dampening to the grid of the righthand triode so that the latter becomes conductive. In consequence thereof the potential of the right-hand anode decreases and thereby the potential of the grid of the lefthand triode is even more decreased, thus finally blocking the left-hand triode. In an exactly analogous manner the trigger arrangement is brought back to the first described condition, termed hereinafter the rest position, if a negative impulse is again applied to the grid over the condenser 16. The right-hand cathodes of all the double triodes are directly connected to ground, while the letthand cathodes are connected to the common conductor '7, which is grounded over a resistor 17` before it is connected to the delay member 8. In the embodiment shown in the drawings the front trigger arrangement Kl is connected with the oscillator 6 over a decoupling stage (not shown). From the operation of the trigger arrangements described hereinabove it will be seen that each trigger arrangement triggers once, when the left-hand anode of the preceding trigger arrangement becomes negative. If the time elapsing between two subsequent triggerings is denoted as the trigger period, it will be seen that the trigger frequency of any front trigger arrangement amounts to twice the trigger frequency of the rear trigger arrangement, because the left-hand anode always becames negative after two triggerings. Thus by the sequence of series-connected trigger arrangements the fre4 quency generated by the oscillator 6 is subdivided in a geometrical progression having the ratio l/ 2.

Each test arrangement includes a double triode 18, the grids of which are connected over resistors 19 with the grids of the corresponding tubes 20. The potentials of the grids of the tubes 18 thus correspond to the potentials of the grids of the tubes 20 of the trigger arrangements. The common cathodes of each tube 18 are connected to a common conductor 9 maintained at a positive potential of approximately volts. Thus the triodes of each tube 18 are normally blocked. The anodes of the tubes 1S are connected to a positive terminal by means of anode resistors 21.

The anodes of the triodes of the tubes 18 are connected over resistors 22 and capacitors 23 with further nonindependent trigger arrangements forming part of indicating arrangements Ax and An and being designed exactly analogous to the trigger arrangements Kx and Kn, so that the corresponding elements thereof are denoted by the same reference numerals as those of the trigger arrangements Kx and Kn.

Between the left-hand anode of the tube 20 of the indicating arrangement and the conductor 24 the indicating lamp (glow lamp) Lx is connected over the decoupling resistors 2S, 27 and condenser 26. The indicating arrangement An is equipped with two lamps Lnl and LnZ which are inserted between the anodes of the tube 20 of the indicating arrangement Au and a common positive potential source.

The conductor 24 is connected to the anode of an output tube 28 forming part of the controlling arrangement 10. The control grid of the tube 28 is connected over a resistor 29 with the right-hand grid of the tube 20 of the indicating arrangement An, so that both grids are irnparted the same potential. The anode of tube 28 is connected to the positive terminal by means of a resistor 30.

The parts denoted by 1-5 in the block diagram shown in Fig. 1 are known per se in the art and need no detailed discussion.

The device described hereinabove operates as follows:

All trigger arrangements oscillate at frequencies decreasing according to a geometrical progression. On the other hand the oscillating device 4 supplies periodically impulses of short duration having a time interval corresponding exactly to the frequency of the vibrations of the escapement of the movement acting upon the microphone 5. Since only every other impulse is transmitted by the trigger arrangement 3, the trigger oscillator produces voltage impulses for instance every 0.4 second for watches having 18,000 beats per hour. A negative voltage impulse is transmitted over the conductor 9 to all cathodes of the testing arrangements P, while a positive impulse is transmitted over the delay member 8 and the conductor 7 to all leftahand cathodes of the trigger arrangements K with a time delay amounting to a few microseconds. By the delayed impulse all left-hand triodes of the trigger arrangements are rendered non-conductive so that they are brought back into the described normal condition. The trigger arrangements continue oscillating, the frcquencies thereof being such that all comparison voltages generated by the trigger arrangements Kl to Kn-l perform a whole number of oscillations in 0.4 second.

Exactly coinciding with the start of the controlling impulse, all cathodes of the tubes 18 in the testing arrangements Px-Pn are imparted a negative potential so that triode of these tubes becomes conductive which is connected to the grid of the associated trigger arrangement Kx-Kn which has a high potential. Thus, according as the right or left-hand triode of the testing arrangement Px-Pfz is rendered conductive, a negative impulse is transmitted to the right or left-hand grid of the tube 20 of the indicating arrangement Ax-An, since the anode voltage of the tube i8 that has been rendered conductive decreases. By this negative impulse the indicating arrangement Ax-An is brought into a definite triggering condition in the manner described hereabove for the triggering arrangements Kx-Km since their design is exactly analogous.

lf the movement of the watch is too fast, the controlling impulse will be generated before the trigger arrangements Kx to K11-1 have carried out a whole number of trigger oscillations or before the trigger arrangement Kn has carried out 22.5 oscillations. Thus in the trigger arrangement Kn that condition will still prevail, which corresponds to the rest condition; that is,the left-hand triode is conductive. The grid voltage of this triode and therefore the grid voltage of the righthand triode of the testing arrangement Pn is high. As soon as the controlling impulse arrives, the right-hand triode of the tube of the testing arrangement Pn is rendered temporarily conductive, the left-hand triode being non-conductive, since the grid thereof is connected to the grid of the blocked triode of the trigger arrangement Kn. Since the right-hand triode of the testing arrangement Pn is rendered conductive, its anode becomes more negative and the grid of the right-hand triode of the indicating arrangement An is imparted a negative impulse which puts the indicating arrangement An in that condition, in which the left-hand triode of the tube 20 is conductive. Therefore the anode of this left-hand triode is at a relatively low potential, which is sufficiently dierent from the positive potential of the voltage source to ignite the glow lamp LnZ, which indicates by the signal -tthat the movement of the watch is too fast.

If the movement of the watch is too slow, the control impulse arrives after completion of the last mentioned half period of the comparison oscillation of the trigger arrangement Kn, and because the latter is now in a condition opposite to that corresponding to the rest condition, the right-hand triodes of the testing and indicating arrangements Pn and An are conductive, so that the lamp Lnl glows, indicating that the watch is too slow.

The remaining indicating arrangements indicate by how much the movement is too fast or slow. For instance, the indicating arrangement Ax is intended for indicating that the movement is too fast or slow by 15 seconds per day, which is equivalent to 17.4 10"5 per second or 6.95X 10-5 per 0.4 second. ln order to obtain a correct indication of this diiference, half the period of the comparison oscillation of the associated trigger arrangement Kx has to be equal to this difference in time, so that for thistrigger arrangement a frequency of 1/6.951 2 1U5 or 7200 cycles per second is obtained. The next indicating stage (not shown) has to be associated with a trigger arrangement operating at exactly half this frequency, i e: at 3600 cycles per second, in order to indicate a difference of 3() seconds per day. The subsequent indicating stages (not shown) correspondingly indicate differences of 1, 2, 4, 8 and 16 minutes per day, the associated trigger arrangements (not shown) operating at frequencies of 1800, 900, 450 225 and 112.5 cycles per second respectively.

The indication of the indicating arrangements Ax to An-l is carried out according to a system different from that of the indicating arrangement An. If the movement is too fast, the right-hand triode of the tube 2i) of the indicating arrangement An is non-conductive and thus also the output tube 28 of the controlling arrangement 10 is non-conductive. Therefore the anode of this output tube 28 is at relatively high potential, so that the lamps Lx-Ln-l, which are connected to the left-hand anodes of the tubes of the indicating arrangements Ax to A11-1, are ignited when these left-hand triodes are conductive. If the movement is too slow and therefore the right-hand triode of the indicating arrangement An is conductive, also the output tube 28 is conductive and thus has a relatively low anode voltage, so that the lamps Lx to Ln-l are ignited when the anode voltage of the left-hand triodes of the indicating arrangements Ax to A11-1 are relatively high. It is thus evident that in a definite moment of the testing o-f the condition of the trigger arrangements Kx to Kn-1 not all of them will indicate a fast movement, but part of them a fast movement and part a slow movement. Therefore, if a watch is fast, only the trigger arrangements indicating a fast movement should indicate. In connection with the indicating stage it has been shown that during a fast movement the lefthand triodes of the indicating arrangements are always conductive so that the left-hand anodes of these tubes are at a lower potential. The same applies to all other stages Ax to Afl-1. Simultaneously at a fast movement the voltage of conductor 24 connected to the anode of the output tube 2S is maintained at a high value in the Way described before, so that in fact in this case all lamps are ignited that are connected to anodes having a lower voltage, which corresponds in fact to a fast movement. Conversely the voltage of the conductor 24 is low at a slow movement and only those lamps are ignited which are connected to indicating arrangements, the lef-hand anode of which has a high voltage, which characterizes de facto a slow movement in this stage.

It should be noted that, of course, the indicating arrangements Ax to Azz-1 maintain the condition which they have once assumed, until the testing device yields a different test result. Thus part of the lamps Lx to Ln-l glows continually during the testing of a watch, one of the lamps Lnl and` Ln2 indicating whether the watch is fast or slow. The operator then only has to add the illuminated numbers, for instance 15 seconds, 1 minute and 4 minutes, in order to obtain the result, that the watch is fast or slow by 5 minutes, 15 seconds, the lamps Lul and Ln2 indicating a fast and slow movement, respectively.

Obviously the device described hereinbefore can indicate a maximal movement difference of 32 minutes. If larger differences are to be indicated correctly, the trigger frequency should be further subdivided by adding further trigger arrangements. This can be useful if the device is also to be applied to the calibration of the escapement before assembly in the movement of the watch.

I Wish it to be understood that I do not desire to be limited to the details described in the foregoing specification and shown in the drawings for obvious modifications will occur to a person skilled in the art.

I claim:l p g r 1. A device for measuring the error of a movement of a watch, comprising in combination, means adapted to convert into electrical signals the acoustical signals caused by the beats of the watch, a first impulse generator controlled by said electrical signals and supplying pairs of impulses of two polarities having the same duration and phase, the time intervals between said pairs of impulses being proportional to the time intervals of the beats of said watch, a stable oscillator supplying oscillations of constant frequency, a plurality of second impulse generators formed respectively, as non-independent symmetrical trigger arrangements connected in series so as to include a first trigger arrangement and a last trigger arrangement; said rst trigger arrangement being supplied with the oscillations of said stable oscillator, each of said trigger arrangements, except said first one, being controlled by the preceding trigger arrangement, the trigger frequency of each of said trigger arrangements, except said first one, amounting to half the trigger frequency of the preceding trigger arrangement, a delay member fed with the impulses of one polarity of said first impulse generator and supplying delayed impulses to said trigger arrangements, except the first one, so as to reset them in the initial position thereof after their triggering action, a plurality of testing arrangements connected respectively to said trigger arrangements except the first one, each of said testing arrangements consisting of a double triode, the grids of which are fed with impulses generated by the corresponding trigger arrangement and the cathode of which is fed with the impulses of the other polarity of said first impulse generator, so as to compare the time intervals of said impulses, and a plurality of indicating arrangements controlled by said testing arrangements,

each of said indicating arrangements consisting of a multivibrator the grids of which are connected with the anodes of the corresponding testing arrangement, said indicating arrangements being responsive to differences of frequencies according to a geometrical progression and corresponding to errors of 1S seconds, 30 seconds, 1 minute, 2 minutes, 4 minutes, 8 minutes and 16 minutes respectively of the movement of the watch.

2. A device for measuring the error of a movement of a Watch, comprising in combination, means adapted to convert into electrical signals the acoustical signals caused by the beats of the watch, a first impulse generator controlled by said electrical signals and supplying pairs of impulses of two polarities having the same duration and phase, the time intervals between said pairs of impulses being proportional to the time intervals of the beats of the watch, a stable oscillator supplying oscillations of constant frequency, a plurality of second impulse generators formed respectively as non-independent symmetrical trigger arrangements connected in series so as to include a first trigger arrangement and a last trigger arrangement, said first trigger arrangement being supplied with the oscillations of said stable oscillator, each of said trigger arrangements, except said first one, being controlled by the preceding trigger arrangement, the trigger frequency of each of said trigger arrangements, except said first one, amounting to half the trigger frequency of the preceding trigger arrangement, a delay member fed with the impulses of one polarity of said first impulse generator and supplying delayed impulses to said trigger arrangements, except the first one, so as to reset them in the initial position thereof after their triggering action, a plurality of testing arrangements connected respectively to said trigger arrangements, except the first one, each of said testing arrangements consisting of a double triode, the grids of which are fed with impulses generated by the corresponding trigger arrangement and the cathode of which is fed with the impulse of the other polarity of said first impulse generator, so as to compare the time intervals of said impulses, a plurality of indicating arrangements connected with said testing arrangements, respectively, so as to include a last indicating '7 arrangement, each of said indicating arrangements consisting of a multivibrator the grids of which are connected with the ano-des of the corresponding testing arrangement, said last indicating arrangement being so controlled by the corresponding testing arrangement as to take a first indicating position when the movement of the watch is slow and a second indicating position when the movement of the Watch is fast, and a controlling device cornprising a vacuum tube the grid of which is connected with one grid of said last indicating arrangement so as to be in a rst electrical condition when said last indicating arrangement is in its first indicating position, and a second electrical condition when said last indicating arrangement is in its second indicating position, said controlling device causing the others of said indicating arrangements to indicate diierences of frequenciesaccording to a geometrical Iprogression and corresponding to errors of 15 seconds, 3() seconds, v1 minute, 2 minutes, 4 minutes, 8 minutes and 16 minutes of the movement of the watch. K 1

References Cited in the le of this patent UNITED STATES PATENTS

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