GB2140939A

GB2140939A - Timepiece regulating system

Info

Publication number: GB2140939A
Application number: GB08409619A
Authority: GB
Inventors: John Henry Noble
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-04-13
Filing date: 1984-04-13
Publication date: 1984-12-05
Also published as: DE3414036A1

Abstract

A timepiece calibration device comprising, in combination, a transducer which produces a first signal representing audible beats emitted by the movement of said timepiece, counting means responsive to said first signal and which generates a second signal proportional to the number of beats in a sample of said beats, timing means which generates a third signal proportional to the sampling time interval, and calculator means activated immediately upon termination of said counting so as to process said second and third signals to compute directly the number of beats sampled per unit time and to deliver an output signal proportional thereto to read-out display means.

Description

SPECIFICATION Timepiece regulating system This invention relates to means for regulating timepieces and more particularly pendulum clocks, and certain mechanical chronometers and watches.

As present there are a number of devices available for watch and clock regulation where which work satisfactorily for modern watches and balance-wheel clocks. However, these instruments can only rate timepieces which have fairly uniform gain or loss rate over short periods (of the order of 45 seconds).

This means they are unsatisfactory for regulating the following: Pendulum clocks as a general class Verge watches Early cylinder watches All early types of escapement most of which have such a wide variation of interval from beat to beat as to be incompatible with existing machines but yet, on a daily basis, will effect an average timekeeping within acceptable limits.

They are therefore regulated at present by the tedious method of observation and adjustment after 24 hours intervals - a process which may take weeks to complete.

The present invention overcomes this problem by counting the number of "beats" of the clock over a selectable period (up to two hours) and dividing automatically this figure by the exact time taken to do so. The result, shown on a digital display, is the equivalent nuber of beats per hour or per minute (selectable). Watchmakers usually know the theoretical "train" (the number of beats per hour) of a given clock, and can then make an adjustment accordingly. The clock is then tested again and adjusted again if necessary.

In practice the facility to rate a clock overthe full two hours will rarely be used, and tests leading to the invention indicate that clocks which previously required 1 to 2 weeks for regulation can now be dealt with in 20 minutes with a high order of accuracy.

Broadly, according to the invention, a timepiece calibration device comprises, in combination, a transducer which produces a first signal representing audible beats emitted by the movement of said timepiece, counting means responsive to said first signal and which generates a second signal proportional to the number of beats in a sample of said beats, timing means which generates a third signal proportional to the sampling time interval, and calculator means activated immediately upon termination of said counting so as to process said second and third signals to compute directly the number of beats sampled per unit time and to deliver an output signal proportional thereto to read-out display means.

Certain embodiments of the invention defined in the preceding paragraph will now be described herein with reference to the acompanying drawings, in which: Figure 1 shows schematically the input section of a quartz beat monitor circuit, and Figure 2 shows the main logic section thereof.

In a first embodiment of the invention, for use with those clocks where the train is not already known, the instrument has a remote sensor which, when in use, is held by a rigid support in position just "ahead" and near the tip of, the minute hand. The passing of the minute hand is detected by the sensor (an infra-red emitter/detector unit) connected to the detector circuit 1 and the flip-flop circuit 2, and this starts the main instrument counting the number of beats. At the next passing of the minute hand, the instrument is automatically stopped and then displays the number of beats counted for one revolution of the minute hand. This figure is the theoreticl number of beats per hour, no matter how fast or slow the clock is running, since the relationship between the number of beats and one revolution of the hand remains the same.

In a second embodiment of the invention, the device operates as follows: A clip-on acoustic pickup such as microphone 3 is attached to the watch or clock and the signal from this is fed to a variable gain amplifier 4 which increases the signal level sufficiently for use in the logic circuit and incidentally provides an output to an earpiece or speaker for listening to the movement.

The amplifier output also passes through a low-pass filter and Schmitt Trigger/Comparator 5, and then triggers a monostable circuit 6 the output of which has a variable pulse width which is controlled from the front panel of the apparatus and is indicated by an LED 7. This enables the device to be made insensitive to unwanted signals for almost the entire period between beats. This pulse then clocks a free-running flip-flop 8 which controls another two LEDs, 9 and 10 alsolocated on said panel. These therefore are "on" alternately as each beat is received, and are used with the gain control 11 and sensitivity (pulse width) control 12 to set up the device to reliably count each beat of a given clock.

After the "start" button 13 is pressed, the next beat to be received activates the beat counter 14 and time interval counter 15. These are clocked from an oven-controlled quartz oscillator 16, which allows the sampletimeto be measured to within 10-6 seconds. While the timing is in progress, the digital display 17 shows the elapsed time in minutes and seconds.

On pressing the "stop" button 18, the next beat to be received stops all counters. This means that only an integral number of beats is timed, no matter when the "stop" button is activated. The calculation sequence of the computation circuit 19 is now automatically activated. Basically, this involves loading a calculator l.C. with signals proportional to the total beat count, followed by a division instruction signal, followed by a signal proportional to the time taken (converted to minutes or hours).

This is achieved by feeding the contents of the (BCD) counters in correct sequence (via three-state buffers) to a 4 bit bus line. This BCD information is then decoded by a BCD-Decimal decoder, the outputs of which activate bilateral switches which in turn make connections between the appropriate terminals on the calculator I.C. The calculator controls the 10 digit display in the usual way.

While this invention was developed especially for "difficult" clocks and watches, it is also very suitable for all other types including quartz and tuning-fork watches and solid-state clocks. In fact its high accuracy will make it an excellent instrumentforthe regulation of chronometers, regulators, observatory clocks and quartz-controlled mechanical clocks.

Claims

1. A timepiece calibration device comprising, in combination, a transducer which produces a first signal representing audible beats emitted by the movement of said timepiece, counting means responsive to said first signal and which generates a second signal proportional to the number of beats in a sample of said beats, timing means which generates a third signal proportional to the sampling time interval, and calculator means activated immediately upon termination of said counting so as to process said second and third signals to compute directly the number of beats sampled per unit time and to deliver an output signal proportional thereto to read-out display means.

2. Atimepiece calibration device as claimed in Claim 1, wherein said counting means comprises a low-pass filter and Schmitt Trigger/Comparator the output of which triggers a monostable circuit which generates pulses of variable width.

3. A timepiece calibration device as claimed in Claim 1, wherein said timing means comprises interval counters clocked from an oven-controlled quartz oscillator.

4. A timepiece calibration device as claimed in Claim 1, wherein said calculator means comprises an l.C. which is fed by BCD counters in sequence via three-state buffers to a bus line connected to a BCD decoder, the outputs of which activate bilateral switches which are connected to said l.C.

5. A timepiece calibration device as claimed in Claim 2, wherein the width of said pulses is variable by means of a manual control and is indicated by a single LED.

6. A time piece calibration device as claimed in Claim 2, wherein said pulses clock a free-running flip-flop which controls a pair of LEDs.

7. Atimepiece calibration device as claimed in Claim 1, wherein said counting means and said timing means are activated by means of a manual start switch, and wherein the operation of said calculator means is simultaneously initiated, by means of a manual stop switch.

8. A timepiece calibration device as claimed in Claim 1,wherein said counting means and said timing means are activated by an output signal from a sensor which detects the passage of the minute hand of said timepiece with reference to a fixed point on said timepiece, and wherein the operation of said calculator means is simultaneously initiated, by a signal from said sensor when said minute hand again traverses said fixed point.