US2532631A

US2532631A - Timepiece calibration recording apparatus

Info

Publication number: US2532631A
Application number: US615958A
Authority: US
Inventors: Walter J Loria; Suhre Jerome
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-09-13
Filing date: 1945-09-13
Publication date: 1950-12-05
Anticipated expiration: 1967-12-05

Description

Dec. 5, 1950 w. J. LORlA EI'AL 2,532,631

TIMEPIECE CALIBRATION RECORDING APPARATUS Filed Sept. 15, 945 s Sheets-Sheet 1 INVENTORS Jana/n5 Sui/RE ATTORN EY Dec. 5, 1950 W. J. LORIA EI'AL TIMEPIECE CALIBRATION RECORDING APPARATUS Filed Sept. 13, 1945 3 Sheets-Sheet 2 m&

me mmm N R l\ W3 m N T lwp A P km x m N? E? mw n" %w\ E Q i Ljd firk Dec. 5, 1950 w. J. LORIA ETAL 3 TIMEPIECE CALIBRATION RECORDING APPARATUS Filed Sept. 13, 1945 3 Sheets-Sheet 5 ATTORNEY Patented Dec. 5, 1950 PATENT OFFICE TIMEPIECE CALIBRATION RECORDING APPARATUS Walter J. Loria and Jerome Suhre, New York, N. Y.

Application September 13, 1945, Serial No. 615,958

9 Claims. 1

The present invention relates to timepiece calibration recording apparatus and more particularly to such apparatus of the all-electronic type which is substantially inertialess for recording the accuracy of a watch or clock in order to observe its rate of gain or loss of time.

In the repair or adjustment of a watch or clock and also in routine tests it is essential to speedily determinethe accuracy thereof. It is also important to know the characteristics of the beat of a watch or clock so that irregular beats may be detected.

Heretofore, it has been usual for the horologist to utilize the old time worn method of observing its rate over a long period of time as compared with a standard chronometer. Other methods have been developed, as for example, the utilization of the stroboscopic principle as applied to visual indicators. Recording instruments have been used with electronic stylus control and embodying rotating drums and stylus action based on the principle of inked ribbon and reciprocating stylus action producing response in the form of a series of dots corresponding to the beat of the watch.

These instruments are incapable of responding to rapid beat movements and give no qualitative analysis either of the beat or of the sounds produced by the movement between the beats. The present invention contemplates the provision of a watch and clock time checking device that is sensitive to the beat of the most rapid 'watch and accurately checks and records the degree of regulation of the timepiece under examination, as well as the nature and characteristic of the beat, and the integrated sounds produced by the movement, to a degree not heretofore obtainable and the operation of which simplifies the known methods of watch and clock regulation.

The present invention also contemplates a means of recording the beat of a watch and the integrated sounds of a watch or clock mechanism so that qualitative analysis thereof may speedily and accurately be made, an accomplishment Furthermore, the invention provides means for recording the duration of the beat of the Watch and the integrated sounds thereof, an achievement which has heretofore been unknown in the horological art.

In accordance with the invention there is provided timepiece calibration recording apparatus comprising an electrical pickup effective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated, a, standard source of periodic reference electrical signals, and a moving carriage adapted to receive a calibration chart movable therewith. The apparatus also includes a recording stylus movable across a chart on said carriage to scan the same and means responsive jointly to the derived signals and the reference signals for causing the stylus to make two groups of periodic traces on a chart on said carriage, each positioned in dependence upon the frequency of one of such signals, whereby the relative patterns of the traces are representative of the calibration of the timepiece.

For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

The accompanying drawings referred to herein and constituting a part hereof illustrate an embodiment of the invention and together with the description serve to explain the principles of the invention.

Figures 1a and lb are schematic wiring diagrams of electric elements used in the apparatus.

Figure 2 is a top elevation, partly in cross section, of one embodiment of the calibrating apparatus according to the present invention.

Figure 3 is a side elevation, partially in cross section, of the apparatus of Figure 2.

Figure 4 is a diagram of a pattern produced by the apparatus.

Referring now to Figures 2 and 3 of the drawings, the timepiece calibration recording apparatus embodying the invention and adapted to make a record on an electrosensitive chart comprises a portable casin including a chassis portion 59 and a hood portion 9. Secured to the side wall 8 of hood 9 there is provided a mounting 3 so arranged that a timepiece such as a watch can be placed thereon with any orientation. Afiixed to the mounting 3 is an electrical pickup effective to derive periodic electrical signals precisely related in frequency to the timing of the timepiece being calibrated. This apparatus may comprise a microphone ii of the crystal or contact type cushioned to absorb outside shocks and effective to develop signals representative of the sound beats of the timepiece in duration and frequency.

The recording apparatus also includes a moving carriage adapted to receive a calibration chart; specifically projecting through base 2 of chassis '60 is a shaft 5 of synchronous motor 6 which is affixed to the underside of base 2. Secured to the shaft 5 of synchronous motor 6 is an electrically conductive disc turntable l for receiving a circular chart 28 of electrosensitive type effective to produce a mark or trace varying in intensity and duration with the value of an electric current passed therethrough. The synchronous motor 6 is of-a conventional type dc signed to rotate the turntable I at 60 R. P. M. when connected to the commercial 60 cycle alterhating-current supply. The recording apparatus further includes a recording stylus movable across the chart 28 on the carriage or turntable I to scan the same. Specifically, the stylus H is reciprocable rad ally across the chart 28 to scan the same with a time-linear trace movement and a rapid retrace movement. The mechanism for imparting this motion to the stylus ll comprises a shaft I 5 projecting through the wall 8 of hood 9 and connected at one end with stylus I I, which is a metal ballpointed needle and so aflixed that outward movement of shaft IE] will project stylus H radially across and toward the center of turntable 1. Shaft H! is arranged within housing 9 to be guided accurately in its movement toward the center point of turntable i by guide bars [2 which guide a cross piece i to which shaft II! is affixed. The shaft l and stylus H are actuated by cam l revolved by a motor IE, affixed to the top of chassis 65. Guide bars l2 aresecured to end plates I! and I8 which are aifixed and secured to the base 2 of chassis 60. Shaft ID has connected or afiixed to its end opposite the stylus a roller 39 which rides on cam I5. The driving mechanism for moving the carrage or turntable l, specifically the synchronous motor 6, operates at a speed which is Very high relative to that of the driving mechanism for the stylus II, that is, the synchronous motor iii. For example, the motor 6 may drive the turntable at 60 R. P. M. while the motor it drives the cam l5 at 1 R. P. M.

Enclosed within housing 9 and affixed to the base 2 of chassis 6B is amplifier unit I9, a conventional high-gain electronic amplifier designed to produce a power output of 5 watts from the beat of the watch under test. Specifically, the amplifier unit l9 includes a conventional pentode amplifier tube Gila having its grid-cathode circuit connected to the microphone pickup d and provided with a grid-leak resistor El and a conventional cathode bias circuit 62. The anode circuit of amplifier 50a is provided with a load resistor 63 coupled by way of a capacitor 64 to the grid-cathode. circuit of a second pentode amplifier 'tube 52, the anode circuit of which is coupled by way of a load res stor 64 and a coupling condenser 55 to the grid-cathode circuit of a power amplifier tube 55. The tubes 52 and 68a. areprovided with grid-leak resistors 67 and 58, respectively, and cathode biasing circuits 69 and 'lfl respectively. The anode circuit of amplifier tube 66 is coupled by way of a transformer 1| to the conductive stylus H by suitable flexible or sliding contact connection (Figure 1a) to allow for its reciprocation. The recording apparatus includes also a standard source of periodic reference signals having a frequency of a value commensurable with the normal frequency of the sound beats of the timepiece. This reference signal source includes, enclosed within housing 9 and affixed to a side wall thereof, a tuning fork unit 29, consisting of tuning fork 43!, made of magnetic material, an actuating electromagnet 43 Wound on a soft iron core 55 mounted at right angles to one of the tines 53 of tuning fork dl. Also at right angles to the opposite tine 5 3 of tuning fork il is a pickup winding 32 which contains a permanent magnet core 24. Tuning fork unit All also includes a feedback amplifier comprising a triode vacuum tube 4? having its gridcathode circuit connected to the pickup winding 42 and its anode circuit coupled by way of load resistor 72 and coupling condenser 575 to the gridcathode circuit of a second triode vacuum tube 46, the anode circuit of which is connected to excite the actuating electromagnet :33 through a load resistor 43a. The tubes .6 and ll are provided with cathode bias circuits 55 and 55, respectively, while tube 46 is provided with a grid-' leak resistor 13.

The recording apparatus of the invention also includes a power supply circuit which may be conventional in construction, comprising an input transformer 23 having a primary winding 23!; connected to

supply circuit terminals

14, 14 through either a push button switch 28 or the contacts 22a of a relay 22, the winding of which is connected across the terminals 14, M through the normally closed contacts of a limit switch 24 actuated b the cross bar M of the stylus reciprocating mechanism. The transformer 23 is provided with a low-voltage secondary winding 23b for energizing the cathode heaters of the several amplifier tubes of the system; with a secondar winding 230 for energizing the filament of a double-anode rectifier tube 26; and witha mid-tapped secondary winding 2301 providing with tube 26 a full-wave rectifying circuit. The filament of tube 26 is connected, through a conventional filter c rcuit 75, to the terminal +B, which is the positive terminal of the power supply output circuit. One of the chokes of the filter unit 15 comprises the winding of a relay 25 having contacts 21, 21a connected to complete the circuits of the motors l5 and 6, respectively.

Tuning fork unit ii] is a precision oscillator circuit whose frequency is mechanically determined by the fundamental frequency of the tuning fork 6| in a conventional manner. Briefly, vibration of tine 54 at the natural frequency of fork 4i induces a periodic voltage of the same frequency in pickup winding 42. This voltage is amplified in

tubes

51 and 46 and. fed back to actuating winding 13. This regenerative action maintains the tuning fork 4! in oscillation at its natural frequency in a conventional manner well understood in the art, and develops across load resistor 43a a periodic voltage constituting the source of reference signals of the apparatus. As stated above, the natural frequency of the tuning fork 6| should be commensurable with the normal frequency of the timepiece to be calibrated, that second, thus developing l2 oscillations per watch beat.

The recording apparatus also includes repeater means for clipping the reference signals to develop a periodic short-duration pulse Wave and means responsive jointly to the signals derived from the watch beat and the reference signals for causing the stylus II to make two groups of periodic traces on a chart 28 on the turntable I, each positioned in dependence upon the frequency of one of such signals. To this end, the voltage across resistor 43a, is fed to vacuum tube 48 included in amplifier unit l9 through a coupling capacitor 16. Tube 48 is connected as a conventional resistance coupled amplifier but biased almost to cut-ofi'. The effect of this excessive bias, provided by cathode bias resistor 50 bypassed by capacitor '11, is to cause rectification and clipping of the output of tuning fork unit 40, producing a unilateral pulsating wave com prising short-duration pulses consisting of only the peaks of the tuning fork oscillations. The output of amplifier tube 48 developed across resistor "is fed through coupling capacitor to the screen grid of vacuum tube 52 in amplifier 19. Thus, both the signals derived from the watch beats and the reference signals are amplifled in tubes 52' and 66 and passed through transformer H to stylus H. Therefore, amplifier 19 comprises means for impressing the signals derived from the watch beats and the clipped reference signals on the stylus l I simultaneously.

In the use of the calibrating apparatus of the invention to ascertain the accuracy of the watch or clock under test, the timepiece is placed on mounting 3 in direct contact with microphone 1. Push button 20 is momentarily depressed, thus energizing the primary winding of transformer 23 and of relay 22, causing relay 22 to close its contacts 22a, thus maintaining flow of current to the primar winding of transformer 23 after removal of pressure on button 20. The energizing current passing through the relay 23 likewise passes through the contact points of limit switch 24. The secondary winding 23d of transformer 23 is connected to relay 25 through the rectifier 26 and, upon the heating of the cathodes of the tubes of the amplifier l9, relay 25 will be energized by the resulting flow of anode current, thus closing contacts 21, 21a of relay 25 and causing motors 6 and [6 to operate. Motors 6 and I6 are synchronous motors which have previously been described as operating at speeds of 60 R. P. M. and 1 R. P. M., respectively, from commercial alternating-current supply sources. The rotation of motor 6 in turn rotates turntable 1 through shaft 5. An appropriately sized discshaped chart of electrically sensitive paper 28, previously described, is placed on turntable I and secured in place and is rotated by the turntable 'l at a rate of 60 R. P. M. Stylus II is brought automatically into contact with the paper placed on the turntable 1 and, as the turntable 1 rotates progressively, moves radially toward the center of the disc, at the same time producing on the surface of the paper black markings corresponding in intensity and duration to the beat of the timepiece under test and to the frequency of the tuning fork 4!. The stylus H is driven by shaft [0, guided, as already stated, by bars l2 and actuated by cam l5 driven by motor Hi. When cam I5 completes one-half of a revolution, stylus ll will have reached its terminal point on its approach to the center of turntable i and the test run will have been completed. The amplified and clipped reference signals from tuning fork unit in impressed on stylus ll produce a series of radial traces 28 each comprising a series of dots representative of the short-duration beats of the tuning fork oscillations. Simultaneously, the amplified signals derived from the watch beats by the microphone 4 produce a series of approxi mately radial traces 28b comprising a series of arcuate dashes representative of the watch beats in duration and time. The watch beats themselves are in the form of pulses of damped transient oscillations, the duration of which indicates to a horologist the nature of the escapement action.

The radial traces 28a corresponding to the frequency of the tuning fork are reference lines and if, for example, a 60 cycle fork is used there will be 60 radial lines equally angularly spaced around the chart 28 whose accuracy will be equal to the standard provided by the tuning fork. Against these traces will be read the record of the rate of gain or loss of the watch under test. If, for example, the watch under test produces a trace which cuts across a space separating two adjacent radial reference traces produced by the fork, there will be a gain or loss depending upon the direction of the curve of the watch trace, which can easily be seen.

The rate of gain or loss may be mathematically determined since, in the instrument described, the turntable 1 rotates at 60 R. P. M. or one revolution per second while the tuning fork 4! has a frequency of 60 cycles per second so that the space between adjacent radial reference traces is equal to one-sixtieth of a second. A gain of one radial line or one-sixtieth of a second in the run which is timed for one-half minute by onehalf revolution of cam 15 shows that the timepiece is gaining one-thirtieth of a second in a minute or two seconds per hour or 48 seconds per day. Since there is considerable space between each reference trace, extremely small variations in time can be readily detected. It will be observed that cutting of the reference traces by the watch traces in a counterclockwise direction indicates a fast-running movement.

The regularity of the beat of the watch under test can quickly be determined by counting the reference traces between the traces produced by the tick of the watch. Equal spacing between traces on a five or six beat watch indicates a regular beat. Uneven spacing indicates an irregular beat.

It is also to be observed that this invention provides a means for instantly determining the number of beats per second produced by the watch, a feature new and unique. The apparatus is also capable of calibrating watches of any beat rate.

Markings appearing between the regular radial watch traces indicate sounds produced by an improperly operating watch which a horologist can interpret. Further, the trace-developing means are inertialess electronic circuit elements and apparatus so that sounds of a duration as brief as 10000 of a second may be recorded. A qualitative analysis of the beat may be made by an observation of the track of light and dark markings within the beat marks which will be of prime importance to the horologist as indicating the condition of the timepiece under test.

While we have described in detail a modification of the present invention illustrated as embodied in a watch rate checking instrument. it is to be understood that changes may occur to those skilled in this art.

The invention in its broader aspects is not limited to the specific mechanism shown and described but departures maybe made therefrom within the scope of the accompanying claims without departing from the principles of the invention and Without sacrificing its chief advantages. V V

What is claimed is:

l. Timepiece calibration recording apparatus comprising: an electrical pickup effective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated; a standard source of periodic reference electrical signals; a moving carriage adapted to receive a calibration chart movable therewith; a recording stylus movable across a chart on said carriage to scan the same; and means responsive jointly to said derived signals and said reference signals for causing said stylus to make two groups of periodic traces on a chart on said carriage, each positioned in dependence upon the frequency of one of said signals, whereby the relative patterns of said traces are representative of the calibration of said timepiece.

2. Timepiece calibration recording apparatus comprising: an electrical microphone effective to derive periodic electrical signals representative of the sound beats of a timepiece being calibrated in duration and frequency; a standard source of periodic reference electrical signals; a moving carriage adapted to receive a calibration chart movable therewith; a recording stylus movable across a chart on said carriage to scan the same; and means responsive jointly to said derived signals and said reference signals for causing said stylus to make two groups of periodic traces on a chart on said carriage, each positioned in dependence upon thefrequency of one of said signals, whereby the relative patterns of said traces are representative of the calibration of said timepiece.

3. Timepiece calibration recording apparatus comprising: an electrical pickup effective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated; a standard source of periodic reference electrical signals having a frequency of a value commensurable with the normal frequency of the sound beats of said timepiece; a moving carriage adapted to receive a calibration chart movable therewith; a recording stylus movable across a chart on said carriage to scan the same; and means responsive jointly to said derived signals and said reference signals for causing said stylus to make two groups of periodic traces on a chart on said carriage, each positioned in dependence upon the frequency of one of said signals, whereby the relative patterns of said traces are representative of the calibration of said. timepiece.

' 4. Timepiece calibration recording apparatus comprising; an electrical pickup elfective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated; a standard source of periodic reference electrical signals; a turntable adapted to receive a circular calibration chart; a recording stylus movable radially across a chart on said carriage .to scan the same; and means responsive jointly to said derived signals and said reference signals for causing said stylus to make two groups of radial periodic traces on a chart on said carriage, each positioned in dependence upon the frequency of one of said signals, where- 8 by the relative patterns of said tracesare representative of the calibration of said timepiece.

5. Timepiece calibration recording apparatus comprising: an electrical pickup effective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated; a standard source of periodic reference electrical signals; a moving carriage adapted' to receive a calibration chart; a recording stylus reciprocable across a chart on said carriage to scan the same with time-linear trace movement and a rapid retrace movement; and means responsive jointly to said derived signals and said reference signals for causing said stylus to make two groups of periodic traces on a chart on said carriage, each positioned in dependence upon the frequency of one of said signals, whereby the relative patterns of said traces are representative of the calibration of said timepiece.

6. Timepiece calibration recording. apparatus adapted to make a record on an electrosensitive chart comprising: an electrical pickup effective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated; a standard source of periodic reference electrical signals; a moving carriage adapted to receive a calibration chart movable therewith; a recording stylus movable across a chart on said carriage to scan the same; and means for impressing both said signals on said stylus simultaneously for causing said stylus to make two groups of periodic traces on a chart on said carriage, each positioned in dependence upon 7 the frequency of one of said signals, whereby the relative patterns of said traces are representative of the calibration of said timepiece.

7. limepiece calibration recording apparatus comprising: an electrical pickup effective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated; a standard source of periodic reference electrical signals; a moving carriage adapted to receive a calibration chart movable therewith; a recording stylus movable across a chart on said carriage to scan the same; driving mechanism for moving said stylus; driving mechanism for moving said carriage at a speed which is high relative to that of said stylus; and means responsive jointly to said derived signals and said reference signals for causing said stylus to maketwo groups of periodic traces on a chart on said carriage, each positioned in dependence upon the frequency of one of said signals, whereby the relative patterns of said traces are representative of the calibration of said timepiece.

8. Timepiece calibration recording apparatus comprising: an electrical pickup effective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated; a standard source of periodic reference electrical signals; repeater means for clipping said reference signals to develop a periodic short-duration pulse wave; a moving carriage adapted to receive a calibration chart; a recording stylus movable across a chart on said carriage to scan the same; and means responsive jointly to said derived signals and said clipped reference signals for causing said stylus to make two groups of periodic traces on a chart on said carriage, each positioned in dependence upon the frequency of one of said signals, whereby the relative patterns of said traces are repr sentative of the calibration of said timepiece.

9. Timepiece calibration recording apparatus adapted to make a record on an electrosensitive chart comprising: an electrical pickup efiective to derive periodic electrical signals precisely related in frequency to the timing of a timepiece being calibrated; a standard source of periodic reference electrical signals; repeater means for clipping said reference signals to develop a periodic short-duration pulse Wave; a moving carriage adapted to receive a calibration chart; a recording stylus movable across a chart on said carriage to scan the same; and means for impressing said derived signals and said clipped reference signals on said stylus simultaneously for causing said stylus to make on said chart one trace comprising a series of dots representative of said reference signals and a second trace comprising a series of dashes representative of said derived signals in timing and duration, whereby the relative patterns of said traces are representative of the calibration of said timepiece.

WALTER J. LORIA. JEROME SUI-IRE.

10 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS