HK1121244B - Alarm watch and mechanism for displaying the alarm time - Google Patents

Description

Alarm watch and mechanism for displaying alarm time

Technical Field

The present invention relates to a mechanical alarm watch including a mechanism for displaying an alarm time based on twenty-four hours. The invention relates more particularly to such alarm time display mechanisms.

Background

Watches equipped with an alarm function and comprising an alarm time indication mechanism are known. Most of these timepieces comprise a trigger that is released every twelve hours, the trigger time of which is indicated by an additional needle. The alarm time is set by moving the additional hand around the dial using the time setting lever. One drawback of this timepiece is that it is not possible to set the alarm time more than twelve hours in advance.

British patent GB1397982 discloses a timepiece which can set an alarm twenty-four hours in advance. The dial of the timepiece comprises additional graduations dividing the circumference of the dial into twenty-four hours. The alarm needle cooperates with the scale to indicate the selected alarm time. Thus, it is possible to select the trigger time as much as twenty-four hours in advance. This prior art solution also has drawbacks. Dividing the dial into twenty-four hours instead of twelve hours is not common and can cause confusion. In this case, there may be an operation error due to misreading of the alarm time. Furthermore, indicating the alarm time with a separate pointer associated with a dial comprising a large number of subdivided scales means that the alarm time cannot be set accurately.

Swiss patent CH 510906 discloses an alarm indicating and releasing device for a timepiece which utilizes a twelve hour dial, but is released only every twenty-four hours. This feature is achieved because the cam is intermittently moved every twelve hours to actuate and stop the trigger once every twenty-four hours. The colored indicia visible through the dial indicate whether the trigger is released in the next or subsequent twelve hours. The solution proposed by this prior art document overcomes some of the aforementioned problems. However, the meaning of the colored indicia is not apparent to the new user. It is also questionable that: without this indication, can someone understand the alarm time setting principle?

Disclosure of Invention

It is an object of the present invention to provide an alarm watch comprising an alarm time indicating means which can be set more than twenty four hours in advance and whose reading is as easy as possible.

It is another object of the present invention to provide an alarm watch in which the alarm time can be set with high accuracy.

The invention therefore provides an alarm watch according to claim 1.

One advantage of the present invention is that the alarm time display means includes a conventional twelve hour display. The display can be read out without difficulty, which limits the risk of errors when selecting the alarm time. Furthermore, the fact that the alarm time is selected using the hour and minute hands provides a more accurate setting of the alarm time.

Another advantage of the invention is that, unlike the difference between the "next twelve hours" and the "next twelve hours" proposed in swiss patent CH 510906, the difference between the morning time and the afternoon or evening time is a common difference that can be easily understood.

It will be appreciated that the principle of indicating time in twenty-four hours using a twelve hour display, accomplished by specifying whether time is included between sub-night and midday (AM) or between midday and sub-night (PM), is not novel in itself. However, these displays relate to the current time rather than the alarm time. Furthermore, these AM/PM current time displays are generally considered redundant, since the wearer of the watch need not in principle utilize such displays to distinguish between night and day. Furthermore, the fact that the twelve hour current time display is accomplished using the AM/PM indicating mechanism necessarily results in an increase in the energy required to operate the watch. In view of the foregoing, it will be apparent to those skilled in the art that AN/PM display is disadvantageously biased.

Surprisingly, all of the above-mentioned drawbacks related to AM/PM displays disappear when this type of display is used to indicate an alarm time. First, according to the above description, the possibility of being able to select the time in a twenty-four hour time period has the advantage of being indiscernible when the time concerned is the alarm time. Furthermore, the alarm time is a static indication that changes only when the wearer of the watch selects a new alarm time. The alarm time indicating mechanism according to the invention is therefore not driven by the watch movement. Therefore, the mechanism does not consume any mechanical energy.

According to an advantageous embodiment of the invention, the watch integrated with the mechanism according to the invention comprises at least two different dials. One of the dials is provided for displaying an alarm time and the other dial is provided for displaying a current time.

Drawings

Other characteristics and advantages of the invention will become clear from a reading of the following description, given purely by way of non-limiting example, with reference to the accompanying drawings. In the figure:

FIG. 1 is a partial cross-sectional view of the gear train of a prior art alarm watch, corresponding to FIG. 2 of British patent No. GB 1397982;

FIG. 2 is a partial cross-sectional view of a gear train of an alarm watch in accordance with an embodiment of the present invention;

FIG. 3 is a perspective elevation view illustrating the release wheel and AM/PM mechanism of the alarm watch shown in FIG. 2.

Detailed Description

To facilitate an understanding of the following description, which relates specifically to the present invention, the description begins by referring to the prior art alarm mechanism of fig. 1.

The movement shown in figure 1 comprises a base plate 10 in which a minute wheel tube 12, an hour wheel tube 16 and a central shaft 18 pivot coaxially. These concentric shafts carry the minute hand 13, the hour hand 17 and the second hand 19, respectively. These needles are provided for indicating time in a usual manner on a 12 hour dial (not shown). To this end, the needles are driven by the movement in a manner known to those skilled in the art. The partial view of fig. 1 shows only the moving piece formed by the wheel 11 and its pinion 14, which is used to kinematically connect the minute pinion 12 to the hour wheel 15.

The watch also includes a trigger mechanism, not shown, and a release mechanism. The mechanism comprises a pinion 21 which is driven coaxially into the pinion 14 of the moving workpiece and meshes with a wheel 22 fitted freely over the hour wheel tube 16. The gear ratio is set such that the movement drive wheel 22 rotates once every twenty-four hours. In fig. 1 it can be seen that the wheel 22 is supported by the hour wheel 15. A trigger release trigger 23, wound with a spring not shown, abuts the bottom surface of the hour wheel pushing it upwards together with the wheel 22.

The plate of the "24 hour" wheel 22 includes three projections 24 arranged at unequal distances from the center of the wheel and angularly offset from each other. The release mechanism also comprises a release wheel 26 frictionally mounted in the shaft of the needle and thus coaxial with the wheel 22, the tube of the wheel 26 carrying an alarm time needle 29. The hand is provided for coordinating with additional indications (not shown) defining a twenty-four hour time circle around the dial face.

In a known manner, the watch also comprises winding and time-setting bars (not shown) for setting the time and moving the alarm time-hand 29. Switching between the time-setting function and the alarm movement function can be effected, for example, by means of a push button (not shown), the function of which is to engage the release wheel 26 with the intermediate wheel, which is itself driven by a sliding pinion (not shown). This type of mechanism is specifically disclosed in swiss patent CH 261676. Thanks to this mechanism, the wearer of the watch can turn the release wheel 26 by rotating the winding and time-setting lever. Therefore, he can move the alarm time pin 29 into a position corresponding to the desired alarm time.

The release mechanism of fig. 1 operates as follows. The plate of the release wheel 26 is perforated with three openings 25 for cooperation with the three projections of the "24 hour" wheel 22. The trigger release trigger 23 permanently presses the wheel 22 against the release wheel 25. When they rotate, at the time set for warning, the three projections 24 of the wheel 22 move relative to the openings 25. In this configuration, which occurs only once every twenty-four hours, the protrusion can enter opening 25, which allows wheel 22 to be pressed against release wheel 26. By pushing of the release trigger 23, the hour wheel 15 moves upward with the wheel 22, which allows the trigger release mechanism to tilt and release the trigger.

Fig. 2 is a partial cross-sectional view of a first embodiment of the present invention. In this first embodiment, the current time display mechanism and the trigger release mechanism are the same as those described with reference to fig. 1. A part of fig. 2 relating to these mechanisms can thus be taken from fig. 1. In particular, elements labeled 10 through 26 are shown in two figures using the same reference numerals. The function of these elements will therefore not be described again.

It has been seen that in the alarm watch shown in figure 1, the tube of the release wheel 26 carries an alarm time pin 29 for cooperation with a twenty-four hour time ring. In the example shown in fig. 2, the alarm time hand 29 is replaced by an alarm time display mechanism according to the invention. This mechanism, generally designated 30, comprises a second hour wheel tube 32 and a second minute wheel tube 34 provided for coaxial pivoting about an axis eccentric with respect to the dial, on which the hands 13, 17 and 19 rotate. Tubes 32 and 34 carry hour hand 33 and minute hand 35, respectively, provided for indicating the time of the alarm on a second twelve hour dial (not shown).

The hour hand 33 and minute hand 35 are kinematically connected in a known manner by means of a moving piece, so that the minute hand completes exactly 12 revolutions for one revolution of the hour hand. Figure 2 shows that the moving workpiece comprises a wheel 38 and an associated pinion 37, which mesh with a minute hand pinion 39 and an hour wheel tube 36, respectively. Fig. 2 also shows that the wheel set formed by wheel 41 and associated pinion 42 connects the release wheel 26 to the moving workpiece wheel 38. The needles 33 and 35 are therefore kinematically connected to the release wheel 26. The gear ratio is set so that the hour hand 33 completes exactly 2 revolutions for each revolution of the release wheel 26. Thus, when the wearer of the watch rotates the release wheel by actuating the winding and time-setting lever (not shown), he also rotates the needles 33 and 35. By varying the pre-selection of the time at which the trigger will be released or triggered, the wearer of the watch therefore also varies the time displayed by the needle. This feature thus avoids any risk of any deviation between the indicated alarm time and the true trigger release time. Importantly however, the above described transmission must be suitably arranged so that the release wheel 26 and the needles 33 and 35 coincide.

Fig. 3 is a top perspective view showing the release wheel 26 and the pinion 42 and wheel 41, where the pinion 42 and wheel 41 connect the release wheel 26 to the alarm time display needles 33 and 35. The wheel 26 also carries a cam, hereinafter AM/PM cam 44. As shown in the figures, the AM/PM cam is formed by the juxtaposition of two halves having semi-circular profiles of different radii. At the joint between the halves 44a, 44b, the cam profile also has two transition sides 45, 46. A lever 48 is provided for cooperating with the cam 44. As can be seen, the lever is formed by a horizontal arm 49 and a vertical pivot 50. The top end of the pivot 50 emerges from the dial (not shown) and carries an AM/PM pin 52. Fig. 3 also shows a spring 53 provided for returning the lever 48 to the control surface of the cam 44.

The AM/PM cam 44 is fixed to the release wheel 26 so that one full rotation of the cam corresponds to two rotations completed by the hour hand 33. In this case, lever 48 meets exactly one of the two transition sides 45 and 46 once per revolution of hour hand 33, since the two transition sides 45 and 46 are half a revolution apart from each other. Thus, the cam 44 may be fixed to the release wheel 26 at an angle such that the lever 48 meeting one or the other of the two transition sides always coincides with the overlap of the hour and minute hands 33, 35 at 12 o' clock. An AM/PM pin 55 carried by lever 48 is provided to indicate whether the alarm time displayed by pins 33 and 35 is between midnight and midday (AM), or between midday and midnight (PM). It is therefore apparent that each time lever 48 encounters one of transition sides 45 or 46, AM/PM pin 52 transitions from one indication to the other.

It should be appreciated at this point that the twenty-four hour alarm time display mechanism in the AM/PM mode described above is a static display that is not driven by the watch movement. In this case, the presence of such a display mechanism has no effect on the standby power.

As has been seen, in the above described embodiment, the release mechanism is the one that has been described as in prior art document GB 1397982. It will be apparent, however, to one skilled in the art that various changes and/or modifications may be made to the embodiments forming the subject matter of this specification without departing from the scope of the invention as defined by the appended claims. In particular, the cooperation between the "24-hour" wheel 22 and the release wheel 26 does not necessarily have to be obtained by axially pressing these two wheels towards each other. It will be appreciated by those skilled in the art that the two wheels may also cooperate, for example, by a cam mechanism. In this case, the circumference of one wheel will be notched, while the other wheel will carry some kind of cam follower.

Claims (5)

1. Alarm watch comprising a mechanical movement-driven time display device comprising at least a first hour hand (17) and a first minute hand (13) fitted to a first dial, an alarm mechanism able to release an alarm at a predetermined alarm time, each twenty-four hours determined manually, and means for displaying the predetermined alarm time, the alarm watch being characterized in that: the alarm time display device comprises at least one second hour hand (33) provided for displaying the alarm time in twelve hours by cooperating with a twelve hour dial, and a mobile indicator (52), wherein the mobile indicator (52) is arranged to occupy a first of two positions when the alarm time is comprised between the midnight and the midnight (AM) and to occupy a second of said two positions when the alarm time is comprised between the midnight and the midnight (PM).

2. Alarm watch according to claim 1, characterised in that the alarm time display means comprise a second minute hand (35).

3. Alarm watch according to claim 2, characterised in that a second hour hand (33) is fitted on the second dial.

4. Alarm watch according to claim 1, 2 or 3, characterised in that the alarm mechanism comprises a release wheel (26) one full rotation of which corresponds to a stroke of a twenty-four hour period by the alarm time, and in that the second hour hand (33) is kinematically connected to the release wheel so that one rotation of said wheel corresponds to two rotations of the second hour hand.

5. Alarm watch according to claim 4, characterised in that it comprises an AM/PM cam (44) fixed to the release wheel (26) and a lever (48) provided for cooperating with the AM/PM cam, said cam comprising two halves of a semicircular profile having different diameters, and in that said cam (44) is angularly fixed to the release wheel (26) so that the "12 hour" position of the second hour hand (33) coincides with the meeting of one or other of the two transition edges (45, 46) formed by the engagement of the lever (48) with said halves.