Tachymeter device and wristwatch

Abstract

The present invention relates to a tachymeter device for indicating an average speed of a moving object, said tachymeter device being attachable to a housing of a wristwatch (1), and comprising a timer and an activator (2) for manually starting the timer, when the object passes a starting mark and stopping the timer, when the object passes a defined distance from the starting mark, a scale (4) for indicating an average speed of the moving object and a hand (5) for indicating a measured average speed on the scale (4), wherein the measured average speed is derived from said defined distance and a time to cover said defined distance measured by the timer, and wherein the hand (5) is configured to make one revolution around the dial of the wristwatch within less than sixty seconds, advantageously within exactly thirty seconds or within exactly ten seconds.

Description

[0001] Tachymeter device and wristwatch

[0002] Technical Field

[0003] The present invention relates to a tachymeter device comprising a speed scale and a hand movable along the speed scale to indicate a speed of a moving object, such as a motor vehicle or boat, according to the preamble of patent claim I . Particularly, the present invention relates to a high-speed tachymeter device. The present invention relates also to a wristwatch comprising a tachymeter device according to the present application.

[0004] Background of the invention

[0005] Stopwatches and timepieces with a tachymeter function are used to measure and indicate the average speed of moving objects like cars, motor bikes or boats based on a distance covered over a time interval. They comprise a scale indicating speed units, for example in kilometers, miles or nautical miles per hour. The stopwatch is started when the moving object passes a start marker and is stopped at a second marker once a known distance had been covered by the moving object. A hand indicates the resulting average speed on the scale. It is often difficult to identify when the moving object, e.g., a car, has reached the defined distance away from the start mark. Therefore, the stopping of the timer can be unprecise and causes flaws in the speed indication, in particular when such moving object, e.g., a racing car, is moving with high speed, or even in the range of world speed records.

[0006] Tachymeter devices on wristwatches are well known from the state of the art. These tachymeter devices usually comprise circular speed scales displayed on a bezel of the watch and a hand configured to make a revolution around the central axis of the watch within exactly sixty seconds. When measuring the time for a moving object to cover a distance of one kilometer, such tachymeter can precisely indicate average speeds below 120km / h. For higher speeds, the speed reading is very difficult and unprecise. For instance, the angle difference between a speed of 400 km / h and 410 km / h is only of 1 .3 degree. In comparison the angle difference between a speed of 90 km / h and 100 km / h amounts to 24 degrees. It is thus impossible to measure average speeds with high precision for objects moving at high speeds, i.e. at speed higher than 200 km / h, with tachymeters known from the state of the art.

[0007] Summary of the invention

[0008] It is an object of the present invention to provide a tachymeter device that allows for reliably measuring the average speed of an object moving at a high speed.

[0009] These and other objects are fulfilled by a tachymeter device according to independent claim 1 and a wristwatch according to independent claim 7. Advantageous features and preferred embodiments of the tachymeter device and the wristwatch according to the invention are disclosed in dependent claims 2 to 6.

[0010] More precisely, the goals of the present invention area chieved by a tachymeter device for indicating an average speed of a moving object, said tachymeter device being attachable to a housing of a wristwatch, and comprising a timer and an activator for manually starting the timer, when the object passes a starting mark and stopping the timer, when the object passes a defined distance from the starting mark, a scale for indicating an average speed of the moving object and a hand for indicating a measured average speed on the scale, wherein the measured average speed is derived from said defined distance and a time to coversaid defined distance measured by the timer, and wherein the hand is configured to make one revolution around the dial of the wristwatch within less than sixty seconds, advantageously within exactly thirty seconds or within exactly ten seconds or within exactly one second By means of such a tachymeter device, it is possible to precisely indicate an average speed of a moving object even for objects moving at high speed. For instance, if the hand of the tachymeter is configured to make a complete revolution, i.e. a revolution of 360 degrees around the central axis of a wristwatch, within ten seconds and the tachymeter is used to measure the time for the moving object to cover one kilometre, the angle difference between a speed of 400 km / h and of 410 km / h amounts to approximately 8 degrees. In comparison, with a traditional tachymeter, i.e. tachymeter with a hand making one revolution within sixty seconds, the angle difference amounts to 1 .3 degree.

[0011] In a first preferred embodiment of the present invention, the hand is configured to make one revolution around the dial within exactly ten seconds.

[0012] In another preferred embodiment of the present invention, the hand is configured to make one revolution around the dial within exactly one second.

[0013] In a further preferred embodiment, the hand is the second hand of a wristwatch. Clearly, a person skilled in the art will be able to provide such a hand in a mechanical or quartz watch. The hand could, for example, be mounted on a mechanism wheel of a mechanical watch or of a quartz watch so that the seconds hand, when used as a hand for the tachometer, can make a revolution around the central axis of the watch in an interval of less than sixty seconds. Thanks to this embodiment, the tachymeter of the present invention can be easily integrated into existing watches without the need for a specific hand to indicate the average speed measured. Alternatively, the hand takes the form of a digital second hand. In this case, the wristwatch advantageously comprises a display for displaying the second hand and a microprocessor that is configured such that the digital second hand rotates around the central axis of the display in less than sixty seconds, preferably within exactly ten seconds or within exactly one second. Advantageously, the scale is part of a circular bezel of a wristwatch or is configured as digital bezel. Alternatively, the scale is designed as a scale part that is arranged detachably at the housing of the wristwatch and the scale part is selected from a set of scales parts comprising a plurality of differing scale parts each having a scale with speed indication units for indicating speed ranges corresponding to differing pre-defined distances and / or pre-defined speed ranges. Thanks to this embodiment, it is possible to choose the scale part according to the expected average speed and / or according to the distance used to measure the average speed.

[0014] In a second aspect, the goals of the present invention are also achieved by means of a wristwatch comprising a tachymeter device according to the present invention.

[0015] Brief description of the drawings

[0016] Several exemplary embodiments of the invention will be illustrated in the following drawings, which merely serve for explanation and should not be construed as being restrictive. The features of the invention becoming obvious from the drawings should be considered to be part of the disclosure of the invention both on their own and in any combination. The drawings show:

[0017] Fig.l : A front view of a tachymeter device according to a first preferred embodiment of the present invention;

[0018] Fig.2: A front view of a tachymeter device according to a second preferred embodiment of the present invention; and

[0019] Fig.3: A front view of a tachymeter device according to a third preferred embodiment of the present invention. Detailed description of preferred embodiments

[0020] Fig.l shows a wristwatch 1 as commonly known from the state of the art. It is therefore omitted here to describe those parts of the watch which are clearly known to a person skilled in the art. Wristwatch 1 comprises a tachymeter device according to a preferred embodiment of the present invention. The tachymeter device comprises a timer and an activator button 2 for manually starting and stopping the timer and a reset button 3 to reset the timer. The timer can be an integral unit of the wristwatch or can be used solely for determining the average speed by the tachymeter device. In addition, the tachymeter device comprises a scale 4 with speed indication marks for indicating an average speed of a moving object. A hand 5 for indicating a measured average speed on the scale 4 is provided. As it can be seen in Fig. 1 , in this embodiment, hand 5 is the second hand of wristwatch 1 .

[0021] The scale 4 is advantageously part of the bezel of the wristwatch 1 or is attachable to the bezel in order to exchange the scale part in dependance of the average speed intended to be measured or of the distance used to measure the average speed. According to the present invention, the hand 5 is configured to make one revolution around the dial within less than sixty seconds, advantageously within exactly thirty seconds or within exactly ten seconds or within exactly one second. It is important to note that the hand 5 is advantageously configured to make a continuous rotation movement around the axis of the dial.

[0022] In the embodiment presented in Fig. 1 the hand 5 is configured to make one revolution around the central axis 6 within exactly ten seconds. When the tachymeter of Fig. 1 is used to measure the average speed of a moving object over a distance of 1 km, the hand indicates on the scale at the “6 o’clock” position and after having completed a full revolution around axis 6 a speed of 240 km / h. Indeed, this position corresponds to 15 seconds measured by the timer. At the position indicated in Fig.l an average speed of approximately 228 km / h. Similarly, the tachymeter of Fig. 1 can be used to measure the average speed of a moving object over 1 mile. In this case, the hand indicates, after having performed one complete revolution around axis 6, a speed of 240 miles / h on the scale at the “6 o’clock” position and at the position indicated in Fig.l an average speed of approximately 228 miles / h.

[0023] Fig. 2 shows a wristwatch 1 comprising a tachymeter device according to a second preferred embodiment of the present invention for measuring average speeds in the ranges of 750 - 900 km / h or miles / h. In this embodiment, the hand is configured to make a revolution around axis 6 within exactly one second. After having made exactly four revolutions around axis 6, the hand indicates thus on scale 4 at the “12 o’clock position” an average speed of 900 km / h or 900 miles / h. At the indicated position in Fig. 2 the hand indicates an average speed of approximately 783 km / h or miles / hour.

[0024] Fig.3 shows a further tachymeter device for indicating an average speed of a moving object according to a third preferred embodiment of the present invention. The tachymeter device shown in Fig. 3 differs mainly in the scale 4 as it corresponds to a pre-defined speed range from 200 miles per hour to 500 miles per hour and in the hand 5, as said hand is configured to make one revolution around axis 6 within ten seconds. Thus, if the hand has a revolution rate of one revolution per ten seconds and the defined distance to measure the average speed of the moving object is one kilometer, after one full revolution of the hand, i.e., after ten seconds, an average speed of 360 km / h or, respectively, the corresponding average speed of ca. 224 miles / h of the moving object will be indicated by the hand at the “twelve o’clock” position. Similarly, after five seconds, i.e., at the “6 o’clock position” an average speed of 447 miles / hour is measured.

[0025] In the following claims the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single unit or step may fulfil the functions of several features recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The terms “essentially”, “about”, “approximately” and the like in connection with an attribute or a value particularly also define exactly the attribute or exactly the value, respectively.

[0026] Any reference signs in the claims should not be construed as limiting the scope.

Claims

Claims1 . Tachymeter device for indicating an average speed of a moving object, said tachymeter device being attachable to a housing of a wristwatch (1 ), and comprising a timer and an activator (2) for manually starting the timer, when the object passes a starting mark and stopping the timer, when the object passes a defined distance from the starting mark, a scale (4) for indicating an average speed of the moving object and a hand (5) for indicating a measured average speed on the scale (4), wherein the measured average speed is derived from said defined distance and a time to cover said defined distance measured by the timer, and wherein the hand (5) is configured to make one revolution around the dial of the wristwatch within less than sixty seconds, advantageously within exactly thirty seconds or within exactly ten seconds.

2. Tachymeter device according to claim 1 , wherein the hand (5) is configured to make one revolution around the dial within exactly ten seconds.

3. Tachymeter device according to claim 1 , wherein the hand (5) is configured to make one revolution around the dial within exactly one second.

4. Tachymeter device according to anyone of claims 1 to 3, wherein the hand (5) is the second hand of a wristwatch.

5. Tachymeter device according to anyone of claims 1 to 4, wherein the scale (6) is part of a circular bezel of a wristwatch.

6. Tachymeter device according to anyone of claims 1 to 4, wherein the scale (4) is designed as a scale part that is arranged detachably at the housing of the wristwatch ( 1 ) and the scale part is selected from a set of scales parts comprising a plurality of differing scale parts each having a scale (4) with speed indication units for indicatingspeed ranges corresponding to differing pre-defined distances and / or pre-defined speed ranges.

7. Wristwatch (1 ) comprising a device according to anyone of claims 1 to 6.

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