FR2779245A1 - TIDE INDICATOR WATCH - Google Patents

Abstract

Tide indicator watch of the type comprising a movable member (3) having a substantially elliptical curve, driven by a clockwork mechanism and a dial (7) comprising time indications, and the movable member (3) of which is driven by the drive pinion for the date indicator crown.

Description

TIDE INDICATOR WATCH

  The present invention relates to the field of

tide calculation.

  It is well known that the sea undergoes, on most coasts, two tidal cycles over a period of just over a day, on average over a period

approximately 24 hours and 50 minutes.

  It is useful to be able to quickly determine the tide height at a given time, or to determine when the tide will reach a minimum height. For this, there are various tools, including tables published by the hydrographic services, such as SHOM in France, rules presenting graphical evaluation means, periodically updated works, such as the "Breton sailor almanac". These tools require a certain mastery to allow estimation

  safely the tide height at a given time.

  It has also been proposed in the prior art, for occasional users, watches

with a tide indicator.

  French patent FR2666664 describes for example a device making it possible, using a classic analog watch movement, comprising a dial as well as hour, minute and second hands, to indicate the heights of the tides and the coefficients of the tides. It consists of a set of gears whose mechanical ratios allow the rotation of the tide hand on the additional eccentric dial, and the hand of the

  coefficients on the additional offset dial.

  French patent FR2662826 also describes a watch comprising a tide indicator member constituted by a tide grid comprising a semi-diurnal tide curve with landmarks moving at a constant angular speed, function of the average period (over a year) of the tide, concentrically with a reading grid comprising a reading mark determining by its point of intersection with the tide curve, the level of the tide corresponding to the time indicated by

watch switch.

  Another French patent FR2645977 describes a watch which comprises a dial provided with a time scale cooperating with needles intended to be driven by the switching of a movement on which the module can be fixed. This dial further comprises a circular graduation of twenty-four hours cooperating simultaneously, on the one hand with a needle driven in rotation by a mechanism of the module at the rate of one revolution per twenty-four hours and, on the other hand with a tide disc rotated by the module mechanism at the rate of one revolution

by lunation.

  These different watches combine in a single case two relatively independent mechanisms, one for driving the hour and minute hands, the other for driving the tide indicator. As the two cycles have periodicities which have no simple common denominator, it is necessary to multiply the components, which increases the manufacturing cost and

  the complexity of these watches of the prior art.

  The object of the invention is to remedy these drawbacks. To this end, the invention relates in its most general sense to a tide indicator watch of the type comprising a movable member having a curve having one or more lobes, driven by a clockwork mechanism and a fixed dial comprising time indications, characterized in that the movable member is driven by the drive pinion of the

date indicator crown.

  According to a particular embodiment the

crown has 31 teeth.

  Advantageously, the movable member is concentric with a fixed dial comprising time markers for determining the situation of the tide

at a specific time.

  According to a first variant, the fixed dial extends over approximately 360 and has 12 time divisions, and in that the movable member has a substantially sinusoidal unilobed curve whose radius R varies angularly as follows: R = R '+ k. sinO / 2 O: R 'denotes the minimum radius, for an angular position of 0 or the maximum value of approximately 360 0 denotes the angular position from a

initial value.

  According to this variant, the movable member is driven by a pinion modified to have twice as many engaging teeth as for driving a date disc. According to a second variant, the fixed dial extends over approximately 348 and has 24 time divisions, and in that the movable member has a substantially sinusoidal bilobed curve whose radius R varies angularly as follows: R = R '+ k. sinO | O R 'denotes the minimum radius, for an angular position of 0 or the maximum value of approximately 360 0 denotes the angular position from a

initial value.

  Advantageously from the point of view of technical simplicity, the movable member has 31 teeth

  for the drive by the date drive pinion.

  Advantageously, from the point of view of precision, the tide indicator watch according to one of these variants comprises a movable member which has 29 teeth for driving by the drive pinion gear of the date. According to a third variant, the movable member has 49 teeth for driving the date pinion, the fixed dial extends over approximately 232 and has 24 time divisions, and in that the movable member has a substantially sinusoidal three-lobed curve whose the radius R varies angularly as follows: R = R '+ k.sin3O / 2 IOR' designates the minimum radius, for an angular position of 0 or the maximum value of approximately 360 0 designates the angular position from a

initial value.

  According to a fourth variant, the movable member

  has 59 teeth for the timing gear drive.

  Tide indicator watch characterized in that the fixed dial extends over approximately 174 and has 24 time divisions, and in that the movable member has a substantially sinusoidal quadrilobed curve whose radius R varies angularly as follows: R = R ' + k. sin2Ol O: R 'denotes the minimum radius, for an angular position of 0 or the maximum value of approximately 360 0 denotes the angular position from a

initial value.

  The invention will be better understood on reading

  the following description, referring to the attached drawings

  o: Figure 1 shows a front view of a watch according to the first variant; FIG. 2 represents a front view of a watch according to the second variant; FIG. 3 represents a front view of a watch according to the third variant; Figure 4 shows a front view of a

  shows according to the fourth variant.

  Figure 1 shows a watch according to a

  first alternative embodiment of the invention.

  The watch comprises in known manner a clockwork mechanism driving the minute hand (1) and

the hour hand (2).

  The indication of the tide is carried out by a movable member (3) in the form of a concentric crown with

the axes of the needles (1, 2).

  This crown (3) has a substantially elliptical curve (4) separating two contrasting areas (5, 6), for example areas of different colors. The lobe-shaped area (6) corresponds to the

relative tide height.

  The curve (4) is substantially sinusoidal. Its radius R varies angularly as follows: R = R '+ k.sinO / 2 O: R' designates the minimum radius, for an angular position of 0 or the maximum value of approximately 360 0 designates the angular position from d 'an initial value. This crown (3) is placed in front of a dial (7) comprising hour markers. This dial is fixed, that is to say that it is not driven by a clockwork mechanism. Optionally, it is possible to provide a dial whose orientation can be changed manually, in order to match a time and a known tide height. The crown (3) is driven by the pinion

  the date indicating crown.

  It may be the pinion of a standard clockwork mechanism, normally intended to include a date crown, from which the date crown has been removed to be replaced by the tide indicator crown (3). It can also be a standard clock mechanism, of which the date indicating crown has been kept, and to which a synchronous crown (3) with

the date indicator crown.

  It may also be a clockwork mechanism designed specifically for a watch according to the invention, comprising a pinion capable of driving a crown associated with a period of approximately 1 revolution per

month.

  For a model with 31 bilobed teeth, the weekly drift compared to the average tide period is around 20 min. It results in a maximum weekly error of the order of 4, with regard to

  reading on the time dial (7).

  This error is perfectly acceptable for several reasons: First of all, such an instrument is intended for an appreciation of the tide situation, more than a

  precise calculation to the nearest centimeter.

  In addition, the tide height is a data whose evolution is generally sought (tide

  rising, falling tide, rather than the absolute value).

  Finally, many parameters induce an imprecision much greater than the intrinsic imprecision of the invention: for example, the position of the moon in its orbit, the swell, local variations in time and the height of the tide, the geometry of the seabed, and sometimes the uncertainty at the foot of the boat. For this reason, the invention makes it possible to respond economically to the problem of producing a watch incorporating tidal calculation functions, with a solution which is very far from the approach of a person skilled in the art of the field of watchmaking, which is held by inescapable prejudices on the priority to be granted

  the precision of the indications of a clockwork mechanism.

  The initial matching of the tide time with the tide height can be carried out as indicated previously by rotating the dial (7), or even by using the date setting button, making it possible to

  modify the position of the movable crown (3).

  The use of the watch is as follows: We start by matching the tide height with the time, at a given moment for example by maritime indications or simply by observing the state of the sea. for example, the vertex (8) of the curve (4) is brought into concordance with the corresponding time marker, the "11 hours and 5 minutes" marker in the example shown in FIG. 1. It will then be possible to predict the tide height at a given time, by appraising the radial length ratio of the surface 4 relative to the colored surface (5). For example, at 5 am, the tide will be low on the example

shown in figure 1.

  We can also determine the time at which the tide will reach a given value. Still in the example of figure 1, the low tide will be reached

at 5 o'clock.

  The crown (3) will progress slowly,

  moving 2/31 of a turn per day.

  Figure 2 shows a front view of a

shows according to the second variant.

  The crown (3) this time has a two-lobed curve (9). The fixed dial no longer has 12, but 24 time indications. These time indications no longer extend over 360 degrees as in FIG. 1, but over

347,776.

  The curve is substantially sinusoidal, with a radius R varying angularly as follows: R = R '+ I k.sinO O: R' denotes the minimum radius, for an angular position of 0 or the maximum value of approximately 360 0 denotes the angular position from a

initial value.

  The crown (3) has 29 teeth of 12.414.

  This variant reduces the error

weekly at 6mn per week.

  Figure 3 shows a front view of a

  shows according to the third variant.

  The crown (3) is modified to present 44 teeth of 8.1820. Curve (10) is a three-lobed curve. The dial (7) has 24 time indications extending over

231.85

  The curve (10) is a substantially sinusoidal curve whose radius R varies angularly as follows: R = R '+ k. sin3O / 2 @ O R 'denotes the minimum radius, for an angular position of 0 or the maximum value of approximately 360 0 denotes the angular position from a

initial value.

  Figure 4 shows a front view of a

  shows according to the fourth variant.

  The crown (3) is modified to present 59

  teeth of 6,112. The curve (11) is a quadrilobed curve.

  The dial (7) has 24 time indications extending

out of 173.8880.

  The curve (11) is a substantially sinusoidal curve whose radius R varies angularly as follows: R = R '+ k.sin2Ol O: R' designates the minimum radius, for an angular position of 0 or the maximum value of approximately 360 0 designates the angular position from a

initial value.

  The number of teeth on the crown (3) is almost double the number of teeth on a date indicator crown. The mechanism doubles the number of teeth on a date indicator crown, which for some

  watch movements, requires minimal evolution.

Claims (11)

R E V E N D I C A T I O N S   1. Tide indicator watch of the type comprising a movable member (3) having a curve (3, 9, 10, 11), driven by a clockwork mechanism and a dial (7) comprising time indications, characterized in that the movable member (3) is driven by the pinion   the date indicating crown.   2. Tide indicator watch according to claim 1 characterized in that the movable member has 31 teeth for driving with the drive pinion. 3. Tide indicator watch according to claim 1 or 2 characterized in that the movable member is concentric with a dial (7) comprising time marks for determining the situation of the tide at a specific time.   4. Tide indicator watch according to one   any of the preceding claims characterized in   that the dial (7) comprising the time indications extends over approximately 360 and has 12 time divisions, and in that the movable member has a curve (3) unilobed.   5. Tide indicator watch according to one   any of the preceding claims characterized in   that the dial (7) comprising the time indications extends over approximately 348 and has 24 time divisions, and in that the movable member has a bilobed curve (9). 6. Tide indicator watch according to at least one   of the preceding claims, characterized in that   the movable member has 29 teeth for driving by   the date drive pinion.   7. Tide indicator watch according to claim 1 or 2 characterized in that the dial (7) comprising the time indications extends over approximately 232 and has 24 time divisions, and in that   the movable member has a three-lobed curve (10).   8. Tide indicator watch according to claim 7 characterized in that the pinion has 44 teeth for driving by the date pinion. 9. Tide indicator watch according to claim 1 or 2 characterized in that the dial (7) comprising the time indications extends over approximately 174 and has 24 time divisions, and in that   the movable member has a quadrilobed curve (11).   10. Tide indicator watch according to claim 9 characterized in that the movable member has 59 teeth for the drive by the pinion date stamp.   11. Tide indicator watch according to one to   less of the preceding claims characterized in that   the dial (7) can be rotated to make   coincide with a known tide time and tide level.