Alarm setting apparatus for timepieces

An alarm setting device for a timepiece that can be operated by means of an axle for adjusting the alarm setting wheel, by rotating it in a clockwise and a counterclockwise directions. The device includes an alarm setting wheel, an alarm intermediate wheel, and an alarm setting cam, all disposed coaxially. The alarm setting wheel is rotated and adjusted by the alarm setting wheel adjusting axle. The alarm intermediate wheel rotates together with a wheel train of a timepiece. The alarm setting cam is provided between said alarm setting wheel and alarm intermediate wheel. A protrusion provided in the alarm setting cam engages with a loose joint provided in the alarm intermediate wheel. Through this engagement, the alarm intermediate wheel drives the alarm setting cam by dragging it loosely. On the respectively facing surfaces of the alarm setting cam and the alarm setting wheel, either an alarm finger or an engaging portion is provided, respectively. Either the alarm finger or the engaging portion has a sloped depression surface and a sloped shoulder, thereby making it possible to perform alarm setting in reciprocal directions.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an alarm setting device, and particularly 
to an alarm setting device that is capable of adjusting the alarm setting 
time by rotating in a clockwise as well as a counterclockwise direction of 
an axle for adjusting the alarm setting wheel. 
2. Prior Art 
Alarm setting devices which can be operated by reciprocal rotation of the 
axle for adjusting the alarm setting wheel to adjust the alarm setting 
time have been known generally. For example, such a type of alarm setting 
device is proposed in Japanese Laid-Open Patent Application No. 53-11816. 
That is, in an alarm setting mechanism wherein an hour hand wheel and an 
alarm setting wheel are disposed coaxially, an engaging portion of the 
alarm setting wheel is provided with a sloped depression surface and a 
sloped shoulder to engage a projection of the hour hand wheel. Also, 
between the alarm setting wheel and the hour hand wheel, an alarm setting 
cam is disposed. This alarm setting cam can be made to swing back and 
forth through a predetermined angle. Furthermore, a finger of the alarm 
setting cam is always positioned on the engaging portion of the alarm 
setting wheel by an elastic arm that is combined with the alarm setting 
wheel to form a single body. 
Then, when the hour hand wheel rotates clockwise, the protrusion of the 
hour hand wheel drops into the engaging portion of the alarm intermediate 
wheel from a position on a finger of the alarm setting cam. Thereafter, 
when this protrusion rises due to the slope of the alarm setting wheel, 
the desired alarm setting operation is performed. On the other hand, when 
the hour hand wheel rotates reversely wherein the protrusion of the hour 
hand wheel is depressed into the engaging portion of the alarm setting 
wheel, the vertical surface of the protrusion of the hour hand wheel 
presses and moves the finger of the alarm setting cam. By doing so, the 
protrusion rises up the slope of the engaging portion of the alarm 
intermediate wheel. 
However, this alarm setting mechanism requires an extremely complicated 
structure including installation of an elastic arm in the alarm setting 
wheel and thereby pushes the cost of manufacturing up. In addition, in 
such conventional types of alarm setting devices for timepieces, the 
elastic arm is combined with the alarm setting wheel to form a single 
unit. Therefore, as a result of use over a long period of time, elastic 
deformation of the elastic arm occurs which results in a disturbance in 
the swinging motion of the alarm setting cam. As a result, it occurs that 
the finger of the alarm setting cam does not reach to the position on the 
engaging portion of the alarm intermediate wheel upon alarm setting time 
with the result that the alarm setting precision is lowered. 
SUMMARY OF THE INVENTION 
Accordingly, it is the general object of the present invention to obviate 
the disadvantages accompanying the prior art and to provide an alarm 
setting device with which the alarm setting time can be adjusted through 
the reciprocal rotation of an axle. 
Another object of the present invention is to provide an alarm setting 
device which is durable and retains its precision over a long period of 
use. 
It is still another object of the present invention to provide an alarm 
setting device with a simple structure and lower manufacturing cost. 
The above mentioned objects of this invention are achieved by providing an 
alarm setting device which includes an alarm intermediate wheel that is 
provided in a wheel train of a timepiece and that is interlocked with the 
time hands, an alarm setting wheel that is held by a main plate coaxial 
with the alarm intermediate wheel in a freely rotatable manner and which 
functions to set the alarm triggering time, an alarm setting cam provided 
between the alarm intermediate wheel and the alarm setting wheel coaxial 
therewith and which rotates by being drawn loosely by the alarm 
intermediate wheel while also moves freely in the axial direction and an 
energizing spring to press the alarm setting cam towards the alarm setting 
wheel. 
The above described basic elements of the alarm setting device of the 
present invention further include two protrusions on the alarm setting cam 
facing towards the alarm intermediate wheel and at least one alarm finger 
or engaging portion provided on the alarm setting cam facing towards the 
alarm setting wheel. The alarm intermediate wheel is further provided with 
at least one loose joint on its side facing towards the alarm setting cam. 
This loose joint is to engage with the protrusion of the alarm setting 
cam. Also, this loose joint is formed to be longer in the circumferential 
direction than the protrusion of the alarm setting cam. This construction 
is provided in order to drag the alarm setting cam loosely to cause it to 
rotate. This in turn makes it possible for the protrusion to rotate for a 
predetermined extent in the circumferential direction within the loose 
joint. At least two engaging portions or alarm fingers engaging with the 
alarm fingers or engaging portions of the alarm setting cam to move in the 
axial direction during the alarming operation are provided. 
Either the alarm fingers or the engaging portions formed on the mutual 
facing sides of the alarm setting cam and the alarm setting wheel are each 
provided with a sloped depression and a sloped shoulder. Therefore, the 
alarm setting operation in the clockwise direction as well as the 
counterclockwise direction is possible. 
Also, either at a location adjacent to the depression on top of the alarm 
finger or at the location adjacent to the depression of the engaging 
portion that corresponds to the foregoing alarm finger, a projection is 
formed. At one of these locations, which is not provided with the 
aforesaid projection, a recess is provided. This recess is for engaging 
with the foregoing projection. Upon engagement between this projection and 
the recess, the protrusion of the alarm setting cam is pressed against a 
wall surface of the loose joint of the alarm intermediate wheel. As a 
result, the alarm intermediate wheel and the alarm setting cam are 
securely joined at the time of alarming operation. Thus, accurate alarm 
setting can be achieved.

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 is a sectional view showing a first preferred embodiment of an alarm 
setting device in accordance with the teachings of the present invention. 
To the main plate 10 of the timepiece, an alarm setting wheel 12 which 
forms the alarm setting wheel of the present invention is rotatably 
coupled. The alarm setting wheel 12 is provided with an elastic, split 
type ring 12a that is combined with the alarm setting wheel 12 in a single 
plastic body. The split type ring 12a is connected to the main plate 10 
fitted through an open hole 10a in the main plate 10. In the inner 
circumference of the alarm setting wheel 12, an hour hand wheel 14 that 
forms an alarm intermediate wheel of this invention is axially and 
rotatably supported. Furthermore, in the inner circumference of the hour 
hand wheel 14a, a minute hand wheel 16 is axially and rotatably held. To 
the minute hand wheel 16, a minute hand gear 18 is frictionally combined. 
The minute hand wheel 16 and the hour hand wheel 14, while not shown in 
the figures, engage with a known wheel train of a timepiece, and are 
rotatably driven at a specified speed by an output from a time reference 
source. Also, the alarm wheel 12 is rotatably driven by an alarm knob 
through an alarm pinion 20. 
The alarm wheel 12 has a bearing wheel 12b that projects from one end of 
the alarm wheel 12. The hour hand wheel 14 is controlled in its axial 
movement by bearing on the ring 12b. Between the alarm setting wheel 12 
and hour hand wheel 14, an alarm setting cam 22 is provided. The alarm 
setting wheel 12, the alarm setting cam 22 and the hour hand wheel 14 are 
shown in detail in the sectional view of FIG. 2. Also, in FIGS. 3 and 4, 
plan views of the alarm setting wheel 12 and the hour hand wheel 14 are 
shown, respectively. 
In the gear face of the alarm setting wheel 12, engaging areas 24 and 26 
are provided. These engaging areas 24 and 26 are in the form of long 
grooves which extend along the circumferential direction and which are 
located at respectively different radial positions. At locations nearby 
the engaging areas 24 and 26, projections 23 and 25 are provided in a 
protruding manner. In a similar manner, the hour hand wheel 14 is provided 
with two loose joining areas 28 and 30 which are made of two long grooves, 
respectively. On the surface of one end of the alarm setting cam, two 
projections 32 and 34 which loosely join with the loose joining areas 28 
and 30 of the hour hand wheel 14 are provided. Also, on the surface of the 
other end of the alarm setting cam 22, alarm fingers 36 and 38 which 
engage with the engaging areas 24 and 26 of the alarm setting wheel 12 are 
provided and form a single body with the alarm setting wheel 22. The 
protrusions 32 and 34 of the alarm setting cam 22 are shorter in length 
along the circumferential direction than the loose joining areas 28 and 30 
of the hour hand wheel 14. Accordingly, it is possible for the alarm 
setting cam to rotate reciprocally for a predetermined amount along the 
circumferential direction against the hour hand wheel 14. This maximum 
rotatability is set to be greater than the allowance for movement of the 
alarm setting cam 22 by way of the slope of the alarm fingers that are 
described later. 
The characteristic features of the embodiment shown in these figures are as 
follows. The projections of the alarm fingers 36 and 38 are sloped. At 
locations nearby the engaging areas 24 and 26 of the alarm setting wheel 
12, the projections 23 and 25 are provided. Furthermore, at the tops of 
the alarm fingers 36 and 38, recesses 35 and 37 which can be engaged with 
the projections 23 and 25 are provided. 
In FIG. 5, against the fixed alarm setting wheel 12, the hour hand wheel 14 
rotates in the direction indicated by the arrow A, and together with it, 
the alarm setting cam 22 also rotates in the direction indicated by the 
arrow A. In the embodiments shown in the figures, a depressed surface 24a 
and a shoulder tab 24b of the engaging area 25 are formed to be nearly 
perpendicular to the alarm setting wheel surface, respectively. On the 
other hand, a depression 36a and a shoulder 36b of the alarm finger 36 are 
formed as sloping surfaces. The projection 23 is provided nearby the 
depression 24a of the engaging area 24 and it is provided with a sloping 
surface 23a in order to make it easy for the alarm finger 36 to ride onto 
it via the slope 23a. A detailed illustration of the other alarm finger 38 
and the engaging area 26 is omitted here, but the relationship is the same 
as that between the alarm finger 36 and the engaging area 24 described 
above. 
In the present invention, high precision in alarm setting can be achieved 
because of the arrangements as follows: A sloping surface 36a of the alarm 
setting cam 22 is provided which makes it possible for the alarm setting 
cam 22 to freely rotate in the forward direction against the hour hand 
wheel 14. Also, because the shoulder 36b of the alarm finger 36 is formed 
to have a sloping surface, the alarm finger 36 of the alarm setting cam 22 
can easily return onto the flat surface of the alarm setting wheel 12 
after the alarming operation. 
As should be apparent from FIG. 1, the alarm setting cam 22 is pressed and 
spring loaded towards the alarm setting wheel 12 by means of a fly spring 
40. The fly spring 40 is fixed to the main plate 10 at its one end by a 
screw 42. The other end of the spring 40 cooperates with a contact 44 
fixed to the main plate 10 and forms an alarm switch. Therefore, the fly 
spring 40 is made of an elastic metal such as phosphor bronze. A contact 
portion 40a is provided at a part of the fly spring 40 which presses the 
alarm setting cam 22 towards the alarm setting wheel 12 by engaging with 
the shoulder 22a of the alarm setting cam 22. Also, as is shown by the 
dotted lines in FIG. 1, when the alarming operation is performed, the fly 
spring 40 comes into contact with the contact 44 and causes the alarm 
circuit to close by means of a lead wire that is not shown in the figures. 
The embodiment according to the present invention is constructed as above 
and with reference to FIGS. 5 through 8, a description will be given of 
its operation. The description is omitted for the operation involving the 
engaging area 26 of the alarm setting wheel 12 and the alarm finger 38 of 
the alarm setting cam 22 which are not shown in the figures. The reason 
for the above is that the operation involving these members is identical 
with the operation of the engaging area 24 and the alarm finger 36 which 
are shown in the figures. 
FIG. 5 shows the position slightly preceding to the alarm setting position. 
In this position, the recess 35 provided on the alarm finger 36 of the 
alarm setting cam 22 engages with the projection 23 provided on the alarm 
setting wheel 12 and through this engagement they maintain their positions 
shown in the figure against the spring force of the fly spring 40 shown in 
FIG. 1. When the hour hand wheel 14 and the alarm setting cam 22 move in 
the direction indicated by the arrow A from the state described above and 
reach the position of the alarm triggering time shown in FIG. 6, the 
sloping surface 36a of the alarm finger 36 meets the depression 24a of the 
engaging area 24. Upon this meeting, the alarm setting cam 22 proceeds to 
the position shown in FIG. 7 because the alarm setting cam 22 itself is 
spring loaded by the fly spring 40. As a result, the fly spring 40 in FIG. 
1 comes in contact with the contact 44. 
In the usual situation, the alarm setting cam 22 rotates together with the 
rotation of the hour hand wheel 14 while maintaining the state wherein its 
protrusion is in contact with a wall surface 28a of the loose joint 28. At 
the same time, the alarm finger 36 of the alarm setting cam 22 approaches 
the engaging area 24 of the alarm setting wheel 12. However, when the 
frictional force between the hour hand wheel 14 and the alarm setting cam 
22 is greater than the frictional force between the alarm setting wheel 12 
and the alarm setting cam 22, the rotation continues with the protrusion 
32 of the alarm setting cam 22 not in contact with the wall surface 28a of 
the loose joint 28 of the hour hand wheel 14, as shown in FIG. 8. The 
alarm time is set to be that when the alarm finger 36 drops into the 
engaging area 24 while the protrusion 32 is in contact with the wall 
surface 28a of the loose joint 28. Therefore, if the alarm finger 36 drops 
into the engaging area 24 when the protrusion 32 is not in contact with 
the wall surface 28a of the loose joint 28, the result is that the actual 
alarm time deviates from the time set for alarming. 
In this embodiment shown here, even when the alarm setting cam rotates with 
the protrusion 32 not in contact with the wall surface 28a of the loose 
joint 28, accurate alarm setting can be performed. The reason for this is 
described below. If the alarm setting cam 22 further continues rotation 
from the state shown in FIG. 8, the recess 35 provided on the alarm finger 
36 engages with the projection 23, as shown in FIG. 5. At this time, the 
fit-joining force between the alarm setting wheel 12 and the alarm setting 
cam 22 becomes greater than the frictional force between the hour hand 
wheel 14 and the alarm setting cam 22. As a result, while the alarm 
setting cam 22 remains stationary, the hour hand wheel 14 rotates until 
the protrusion 32 comes into the contact with the wall surface 28a of the 
loose joint 28. Thereafter, if the hour hand wheel 14 continues to rotate, 
protrusion 32 of the alarm setting cam 22 is pressed by the wall surface 
28a of the loose cam 28 of the hour hand wheel 14 to cause the alarm 
setting cam 22 to rotate together with the hour hand wheel 14. 
Accordingly, the dropping of the alarm setting cam 22 is performed 
reliably and also a high precision in alarm setting can be obtained. 
The degree of inclination of the sloping surface 36a of the alarm finger 36 
can be readily determined by considering the frictional force between the 
alarm setting cam 22 and the alarm setting wheel 12. 
In FIG. 7, when the hour hand wheel 14 is rotated in a direction opposite 
to the direction indicated by the arrow A for the purpose of adjusting the 
time, etc. or when the alarm setting wheel 12 is rotated in the direction 
indicated by the arrow A in order to adjust the time, the alarm finger 36 
can move up from the engaging area 24 in a manner that the sloping surface 
36a of the alarm finger 36 runs up and over the depression 24a of the 
projection 23. 
In this embodiment, the depth of the recess 35 is made relatively shallow 
so that the engagement between the recess 35 and the projection 23 can be 
easily broken by the manual operation that is performed at a relatively 
high speed and large rotating force when reversely rotating the hour hand 
wheel 14. As described above, in this embodiment, when adjusting the alarm 
setting time or the actual time, the shaft for such adjustment can be 
rotated in both forward and backward directions. Also, the alarming 
operation can be triggered exactly at the time set for giving the alarm. 
FIG. 9 shows another embodiment in accordance with the teachings of the 
present invention. The characteristics and features of this embodiment are 
that a projection 23' is formed at the top of the alarm finger 36 and that 
nearby the engaging area 24 of the alarm setting wheel 12, a recess 35' 
which can engage with the projection 23' is provided. Since the operation 
and the effect of this embodiment is similar to that of the embodiments 
described above, a detailed description of this embodiment is omitted. 
Referring to FIG. 10, shown therein is a second preferred embodiment of an 
alarm setting device in accordance with the teachings of the present 
invention. FIGS. 11 through 13 show sectional side elevational views of 
the essential portions of FIG. 10. In FIG. 11, by a fixed contact plate 
112 that is fixed to the main plate 110 of the timepiece as well as by a 
dust cover 114, a shaft 116 for adjusting an alarm setting wheel is 
axially and freely rotatably supported. To one end of the axle 116 for 
adjusting the alarm setting wheel, a knob for adjusting the alarm setting 
wheel (not shown in the figures) is fixed. 
The first alarm setting cam mechanism includes a shaft 116 for adjusting 
the alarm setting wheel, a first alarm setting wheel 118 that is the alarm 
setting wheel of the present invention, an alarm setting cam 130 and a 
first alarm intermediate wheel 124 that forms an alarm intermediate wheel 
of the present invention. The second alarm setting cam mechanism includes 
a second alarm setting wheel 144 and a second alarm intermediate wheel 
152. 
Firstly, a description will be given of the first alarm setting cam 
mechanism. To the axle 116 for adjusting the alarm setting wheel, the 
first alarm setting wheel 118 is fixed. On the gear face of the first 
alarm setting wheel 118, two engaging portions 120 and 122 are provided at 
mutually opposite radial positions. Also, the first alarm intermediate 
wheel 124 is axially and freely rotatably supported by the axle 116 for 
adjusting the alarm setting wheel. On the gear surface of the first alarm 
intermediate wheel 124, two projections 126 and 128 are formed integrally 
with the intermediate wheel 124. The first alarm intermediate wheel 124 
engages with a day wheel (not shown in the figures) and rotates once every 
three hours, just as the minute wheel. 
In addition, between the first alarm setting wheel 118 and the first alarm 
intermediate wheel 124, the alarm setting cam 130 is axially supported to 
rotate and slide freely on the axle 116 for adjusting the alarm setting 
wheel. In the gear face of the alarm setting wheel 130 that faces towards 
the first alarm intermediate wheel 124, two loose joints 132 and 134 are 
formed. These loose joints 132 and 134 serve to loosely join with the 
projections 126 and 128 of the first alarm intermediate wheel 124 and also 
make it possible for the alarm setting cam 130 to rotate in mutually 
reciprocal directions for a predetermined amount along the circumferential 
direction against the first alarm intermediate wheel 124. In this 
embodiment, the loose joints 132 and 134 are formed as throughholes. Also, 
on the gear wheel surface of the alarm setting cam 130 that faces to the 
first alarm setting wheel 118, two alarm fingers 136 and 138 which are to 
engage the engaging portions 120 and 122 of the first alarm setting wheel 
118 are formed integrally with the alarm setting cam 130. Through the 
engagement between the engagement portions 120 and 122 and the alarm 
fingers 136 and 138 desired alarming operations are performed. 
The description now will be given of the second alarm setting cam 
mechanism. 
The second alarm setting wheel 144 is freely rotatably supported on axle 
142 which is fixed to the backing plate of the device 140. On the gear 
face of the second alarm setting wheel 144, two engagement portions 146 
and 148 are formed at mutually different radial positions. The second 
alarm setting wheel 144 engages with an adjusting pinion 150 that is fixed 
to one end of the axle 116 for adjusting the alarm setting wheel. 
Therefore, by rotating the knob for adjusting the alarm setting wheel, 
together with the first alarm setting wheel 118, the second alarm setting 
wheel 144 is set at a desired alarm time position. Also, a second alarm 
intermediate wheel 152 is freely rotatably supported by the axle 142. The 
second alarm intermediate wheel 152 engages with the first alarm 
intermediate wheel 124 and rotates at a ratio of once every twelve hours. 
Furthermore, on the gear face of the second alarm intermediate wheel 152, 
alarm fingers 154 and 156 which engage with the engaging portions 146 and 
148 of the second alarm setting wheel 144 are formed integrally with the 
second alarm intermediate wheel 152. 
In addition, to a seat 158 that is fixed to the main plate 110, one end of 
a movable contact plate 160 is fixed by means of a screw 161. This movable 
contact plate 160 is made of an elastic metal such as phosphor bronze. The 
movable contact plate 160 presses the first alarm setting wheel 118 and 
the second alarm intermediate wheel 152 towards the alarm setting cam 130 
and the second alarm setting wheel 144, respectively. With such a 
construction, the movable contact plate 160 comes into contact with the 
fixed contact plate 112 and the alarming circuit that is connected to the 
contact plates 112 and 160 is actuated. That is, the engaging portions 146 
and 148 of the second alarm setting wheel 144 engage with the alarm 
fingers 154 and 156 of the second alarm intermediate wheel 152 while the 
engaging portions 120 and 122 of the first alarm setting wheel 118 engage 
with the alarm fingers 136 and 138 of the alarm setting cam 130. 
The characteristic features of this embodiment are as follows. The sloped 
depression and the sloped shoulder are provided either for the engaging 
portion of the first alarm setting wheel or for the alarm finger of the 
alarm setting cam and also either for the engaging portion of the second 
alarm setting wheel or for the alarm finger of the second alarm 
intermediate wheel. In addition, at either one of the locations adjacent 
the depressions of the engaging portion of the first alarm setting wheel 
or adjacent the depressions of the top of the alarm finger of the alarm 
setting cam, a projection is provided, while at the other one of the 
locations, the recess that can be engaged with the projection is provided. 
In other words, in this embodiment, as shown in FIG. 14, the alarm finger 
136 (138) of the alarm setting cam 130 is provided with a sloped 
depression 162 (164) and a sloped shoulder 166 (168). Also, as shown in 
FIG. 15, the alarm finger 154 (156) of the second alarm intermediate wheel 
152 is provided with a sloped depression 170 (172) and a sloped shoulder 
174 (176). Consequently, during the adjustment of the alarm time, the 
alarm finger 136 (138) and 154 (156) are depressed or shouldered by means 
of the depression 162 (164) and 170 (172) and the shoulders 166 (168) and 
174 (176). Therefore, not only by the forward rotation of the axle for 
adjusting the alarm setting wheel but also by the backward rotation 
thereof, the time set for alarming can be adjusted. 
Furthermore, as shown in FIG. 14, at a location adjacent the depressions 
162 (164) on the top of the alarm finger 136 (138) of the alarm setting 
cam 130, a projection 178 (180) is a single unit with the alarm finger 136 
(138). On the other hand, at a point adjacent the depression 182 (184) of 
the engaging portion 120 (122) of the first alarm setting wheel 118, 
recess 186 (188) that can engage with the projection 178 (180) is formed. 
By means of the engagement of the projection 178 (180) with the recess 186 
(188), the protrusion 126 (128) of the first alarm intermediate wheel 124 
is pressed against the wall surface 190 (192) of the loose joint 132 (134) 
of the alarm setting cam 130. As a result, high precision in alarm setting 
can be obtained. 
The second embodiment according to the present invention is constructed as 
described above and hereunder will be given a description of its 
operation. First, the description will start with the operation for 
setting the alarming time. 
As should be clear from FIG. 11, when the knob for adjusting the alarm 
setting wheel is rotated, the first alarm setting wheel 118 that is fixed 
to the axle 116 for adjusting the alarm setting wheel is rotated. Also, 
through the adjusting pinion 150, the alarm setting wheel 144 is rotated. 
Accordingly, the first alarm setting wheel 118 and the second alarm 
setting wheel 144 rotate for a predetermined extent against the alarm 
setting cam 130 and the second alarm intermediate wheel 152, respectively, 
and they are positioned at rotated positions corresponding to the desired 
time for alarming. At this time, the first alarm setting wheel 118 and the 
second alarm setting wheel 144 are clicked by the click lever that is 
omitted from the figures. In this way, the desired alarm setting position 
can be obtained. Then, the adjusting of the set alarming time can be done 
by the forward or backward rotation of the axle 116 for adjusting the 
alarm setting wheel. 
As shown in FIG. 14, the alarm fingers 136 and 138 of the alarm setting cam 
130 are provided with sloped depressions 162 and 164 and sloped shoulders 
166 and 168. Similarly, as shown in FIG. 15, the alarm fingers 154 and 156 
of the second alarm intermediate wheel 152 are provided with sloped 
depressions 170 and 172 and sloped shoulders 174 and 176, respectively. 
Consequently, the alarm fingers 136 and 138 and 154 and 156 which are 
respectively depressed into the engaging portions 120 and 122 and 146 and 
148 are able to return towards the gear wheel surfaces via the depressions 
162, 164, 170, 172 or the shoulders 166, 168, 174 and 176. Hence, the 
alarm setting time can be adjusted by the forward or backward rotation of 
the axle 116 for adjusting the alarm setting wheel. 
Also for adjusting the actual time, by the same operation described above, 
the alarm setting cam 130 and the second alarm intermediate wheel 152 can 
be optionally rotated against the first alarm setting wheel 118 and the 
second alarm setting wheel 144, respectively, through the operation of the 
time adjusting knob (not shown in the figures). Therefore, by the 
reciprocal rotation of the time adjusting knob, the time can also be 
adjusted. 
As shown in FIG. 11, when a wheel train of the timepiece continues to be 
driven when it is set at a desired time for alarming, the first alarm 
intermediate wheel 124 that is engaged with the minute wheel rotates at a 
ratio of once every three hours while the second alarm intermediate wheel 
152 that engages with the first alarm intermediate wheel 124 rotates once 
every twelve hours. Then, when the time reaches the point several minutes 
before the time set for alarming, as shown in FIG. 15 the alarm fingers 
154 and 156 of the second alarm intermediate wheel 152 fall into the 
engaging portions 146 and 148 of the second alarm setting wheel 144. At 
this time, as shown in FIG. 12, the movable contact plate 160 releases the 
spring load onto the second alarm intermediate wheel 152 and keeps the 
spring load or bias only onto the first alarm setting wheel 118. In an 
ordinary situation, the alarm setting cam 130 rotates together with the 
rotation of the first alarm intermediate wheel 124 with the protrusions 
126 and 128 in contact with the wall surfaces 190 and 192 of the loose 
joints 132 and 134. At the same time, the alarm fingers 136 and 138 formed 
on the alarm setting cam 130 approach the engaging portions 120 and 122 of 
the first alarm setting wheel 118. However, when the frictional force 
between the first alarm intermediate wheel 124 and the alarm setting cam 
130 is greater than the frictional force between the first alarm setting 
wheel 118 and the alarm setting cam 130, as shown in FIG. 14 (A), the 
rotation continues in the state with the protrusions 126 and 128 of the 
first alarm intermediate wheel 124 are not in contact with the wall 
surfaces 190 and 192 of the loose joints 132 and 134 of the alarm setting 
cam 130. The alarm setting time is set to occur when the alarm fingers 136 
and 138 fall into the engaging portions 120 and 122 and when the 
protrusions 126 and 128 are in contact with the wall surfaces 190 and 192 
of the loose joints 132 and 134. Consequently, if the alarm fingers 136 
and 138 fall into the engaging portions 120 and 122 when the protrusions 
126 and 128 are not in contact with the wall surfaces 190 and 192 of the 
loose joints 132 and 134, the actual alarming time deviates from the time 
set for actuating the alarm. In this second embodiment, as described 
above, even when the alarm setting cam 130 rotates when the protrusions 
126 and 128 are not in contact with the wall surfaces 190 and 192 of the 
loose joints 132 and 134, accurate alarm triggering could be performed. 
When the alarm setting cam 130 continues to further rotate from the state 
shown in FIG. 14 (A), the projections 178 and 180 provided on the alarm 
fingers 136 and 138 engage with the recesses 186 and 188 as shown in FIG. 
14 (B). At this time, the fit-jointing force between the first alarm 
setting wheel 118 and the alarm setting cam 130 becomes greater than the 
frictional force between the first alarm intermediate wheel 124 and the 
alarm setting cam 130. As a result, the first alarm intermediate wheel 124 
rotates until the projections 126 and 128 come into contact with the wall 
surfaces 190 and 192 of the loose joints 132 and 134 and the alarm setting 
cam 130 remains stationary. Thereafter, if the first alarm intermediate 
wheel 124 further continues to rotate, the alarm setting cam 130 rotates 
pressed by the protrusions 126 and 128 of the first alarm intermediate 
wheel 124 and the projections 178 and 180 of the alarm fingers 136 and 138 
ride up from the recesses 186 and 188 of the first alarm setting wheel 118 
through the sloping surfaces formed in these projections 178 and 180. 
Then, when the time set for alarming that is indicated by the chained line 
is reached, as shown in FIG. 14 (C), the ends of the projections 178 and 
180 are located at the ends of the depressing surfaces 182 and 184 of the 
engaging portions 120 and 122 of the first alarm setting wheel 118. From 
this state, the alarm fingers 136 and 138 of the alarm setting cam 130 
fall into the engaging portions 120 and 122 of the first alarm setting 
wheel 118 by means of the depressing surfaces 162 and 164, as shown in 
FIG. 14 (D). At this time, as shown in FIG. 13, the movable contact plate 
160 comes into contact with the fixed contact plate 112. By this contact, 
the alarm operation circuits including the alarm circuit and the timer 
circuit which are connected to these contact plates 112 and 160 are 
actuated. 
Thereafter, if the first alarm intermediate wheel 124 continues to rotate, 
the alarm setting cam 130 rotates depressed by the protrusions 126 and 128 
of the first alarm intermediate wheel 124 and the alarm fingers 136 and 
138 return towards the gear wheel surfaces from the engaging portions 120 
and 122 of the first alarm setting wheel 118 by way of the shoulders 166 
and 168. At this time, the first alarm setting wheel 118 presses the 
movable contact plate 160 against the spring force of the movable contact 
plate 160. Consequently, both contact plates 112 and 160 are released from 
contacting and the alarming operation is completed. 
As described above, in the second embodiment and as shown in FIG. 14 (B), 
immediately before the alarming time occurs, by means of the engagement 
between the projections 178 and 180 and recesses 186 and 188, the 
protrusions 126 and 128 of the first alarm intermediate wheel 124 are 
pressed into contact with the wall surfaces 190 and 192 of the loose 
joints 132 and 134 of the alarm setting cam 130. Therefore, as is shown in 
FIG. 14 (C), the alarm operation is performed with high precision. 
In addition, the contact between the contact plates 112 and 160 is 
performed by means of the depressing operation of the alarm setting cam 
130 that rotates once every three hours. As a result, in comparison with 
the use of a twelve hour wheel as in the conventional practice, higher 
precision in alarm setting can be obtained. Also in the embodiment 
described above, the projections 178 and 180 are provided at locations 
adjacent the depressions 162 and 164 at the tops of the alarm fingers 136 
and 138 of the alarm setting cam 130. On the other hand, the recesses 186 
and 188 which can engage with the projections 178 and 180 are provided at 
locations adjacent the depressions 182 and 184 of the engaging portions 
120 and 122 of the first alarm setting wheel 118. However, it may be 
designed as follows. That is, the projections could be provided at 
locations adjacent the depressions 182 and 184. Then, through the 
engagements between the projections 178 and 180 and the alarm fingers 136 
and 138 of the alarm setting cam 130, the protrusions 126 and 128 of the 
first alarm intermediate wheel 124 are pressed into contact with the wall 
surfaces 190 and 192 of the loose joints 132 and 134 of the alarm setting 
cam 130. In this case, the spring force of the movable contact plate 160 
must be set to bring about the following condition. That is, the 
frictional force between the first alarm setting wheel 118 and the alarm 
setting cam 130 which depends on the engagement between the alarm fingers 
136 and 138 with the projections must be greater than the frictional force 
between the first alarm intermediate wheel 124 and the alarm setting cam 
130. 
Furthermore, it may be constructed as follows. That is, the engaging 
portions 120 and 122 and the recesses 186 and 188 of the first alarm 
setting wheel 118 could be formed on the alarm setting cam 130; while the 
alarm fingers 136 and 138 of the alarm setting cam 130 could be formed on 
the first alarm setting wheel 118. In addition, it is also an acceptable 
construction which is within the teachings of the present invention that 
the loose joints 132 and 134 of the alarm setting cam 130 could be formed 
in the first alarm intermediate wheel 124 with the protrusions 126 and 128 
of the first alarm intermediate wheel 124 formed in the alarm setting cam 
130. 
In this embodiment, the foregoing recess 186 can be formed relatively 
shallow so that the engagement between the recess 186 and the projection 
178 can be released easily by the manual rotational force which occurs at 
a relatively high speed and with a high amount of force during the reverse 
rotation of the first alarm intermediate wheel 124. 
Referring to FIG. 16, shown therein is the third embodiment of an alarm 
setting device in accordance with the teachings of the present invention. 
In conjunction with this figure, firstly, a description will be given of 
the wheel train of the timepiece. An axle 218 is supported axially by main 
plates 210, 212 and 214 and a case 216 in a freely rotatable manner. To 
the axle 218, a second hand wheel 220 is fixed. The second hand wheel 220 
engages with the fifth wheel 222 that is held freely rotatably and axially 
by the main plate 214 and a case 216. Also, in the outer circumference of 
the axle 218, a minute hand wheel 224 is held axially and freely 
rotatable. To the minute hand wheel 224, a minute hand gear 226 is 
frictionally connected. In addition, in the outer circumference of the 
minute hand wheel 224, hour hand wheel 228 is held axially and freely 
rotatable. These minute hand wheel 224 and hour hand wheel 228 engage with 
a day wheel 230 that is held axially by the main plate 212 and freely 
rotatable. 
Next, a description will be given of the alarm setting cam mechanism. An 
alarm setting axle 232 is coupled freely rotatably and axially by the main 
plates 210 and 212 and the case 216. The alarm setting axle 232 is the 
axle for adjusting the alarm setting wheel. To one end of the alarm 
setting axle 232, an alarm setting knob 234 is fixed. Also, to the main 
plate 212, an alarm setting wheel 236 is freely rotatably coupled. The 
alarm setting wheel 236 is constructed to rotate by interlocking with the 
alarm setting axle 232. As is generally known, the alarm setting wheel 236 
has an elastic, split type ring 236a that is formed integrally with the 
plastic body of the alarm setting wheel 236. This elastic, split type ring 
236a is fitted and connected to an open hole 212a provided in the main 
plate 212. 
To the alarm setting axle 232, an alarm setting wheel 238 is fixed. On the 
gear face of this alarm setting wheel 238, two engaging portions 240 and 
242 are formed at mutually different positions in the direction of the 
diameter. Also, by the alarm setting axle 232, an alarm intermediate wheel 
244 is axially and freely rotatably coupled. This intermediate wheel 244 
is provided on its gear face with two protrusions 246 and 248 which are 
combined with the alarm intermediate wheel 244 to form a single unit. 
The alarm intermediate wheel 244 is constructed to rotate once every twelve 
hours by interlocking with the wheel train of the timepiece. In other 
words, by the main plate 214 and the case 216, a ten minute wheel 250 is 
held axially and freely rotatably. This ten minute wheel engages with a 
second hand pinion 252 formed in the second hand wheel 220, as well as 
with the minute hand gear 226. Also, by the main plates 210 and 212 and 
the case 216, a two hour wheel 254 that engages with the ten minute wheel 
250 is held axially and freely rotatably. This two hour wheel 254 engages 
with a four hour wheel 256 that is held axially and freely rotatably by 
the main plates 210 and 212. Furthermore, the four hour wheel 256 engages 
with the alarm intermediate wheel 244. 
FIG. 17 shows a plan view of the ten minute wheel 250 and the two hour 
wheel 254. As should be evident from FIG. 17, the ten minute wheel 250 is 
provided with two intermittent feed teeth 250a, and the two hour wheel 254 
is provided with twelve engaging points 254a which are to engage with the 
intermittent feed teeth 250a. The engaging points 254a of the two hour 
wheel 254 are engaged with the intermittent feed teeth 250a of the ten 
minute wheel 250 such that the engaging point 254a is caught between the 
two intermittent feed teeth 250a. Accordingly, the two hour wheel 254 
rotates intermittently for only 30 degrees while the ten minute wheel 250 
completes one rotation. 
As described above, one of the characteristic features of this embodiment 
is that the alarm intermediate wheel 244 is driven intermittently by 
engaging with the wheel train of timepiece. As a result, a high precision 
in alarm setting can be obtained. 
In addition, between the alarm setting wheel 238 and the alarm intermediate 
wheel 244, an alarm setting cam 258 is held axially, freely rotatably and 
freely slidably against the alarm setting axle 232. On the gear face of 
the alarm setting cam 258 that faces towards the alarm intermediate wheel 
244, two loose joints 260 and 262 are provided. These loose joints 260 and 
262 are to loosely engage with the protrusions 246 and 248 of the alarm 
intermediate wheel 244 and to make it possible for the alarm setting cam 
258 to rotate for a predetermined extent in the circumferential direction 
reciprocally against the alarm intermediate wheel 244. In this embodiment, 
the loose joints 260 and 262 are provided in the form of loose joint 
grooves. Also, on the gear surface of the alarm setting cam 258 that faces 
to the alarm setting wheel 238, two alarm fingers 264 and 266 which are to 
engage with the engaging portions 240 and 242 of the alarm setting wheel 
238 are formed integrally with the alarm setting cam 258. Through the 
engagement between these engaging portions 240 and 242 with the alarm 
fingers 264 and 266, a desired alarm setting operation as will be 
described below can be performed. 
Furthermore, to the main plate 212, one end of a movable contact plate 268 
that is made of an elastic metal plate such as phosphor bronze is fixed. 
The other end of this movable contact plate 268 spring biases the alarm 
setting wheel 238 towards the alarm setting cam 258. Also, to the main 
plate 212, a fixed contact plate 270 that is able to come into contact 
with, as well as to be disengaged from the movable contact plate 268, is 
fixed. With this construction, when the engaging portions 240 and 242 of 
the alarm setting wheel 238 engage with the alarm fingers 264 and 266 of 
the alarm setting cam 258, the movable contact plate 268 contacts the 
fixed contact plate 270 and the alarming operation circuit connected to 
these contact plates 268 and 270 is actuated. 
Characteristic points in this embodiment are as follows. That is, a sloped 
depression and a sloped shoulder are provided either in the engaging 
portion of the alarm setting wheel or in the alarm finger of the alarm 
setting cam. Also, at either one of the locations adjacent the depression 
of the engaging portion or adjacent the depression at the top of the alarm 
finger, a projection is formed; while at the other one of the locations, a 
recess that can engage with the projection is formed. 
Therefore, in this embodiment, the alarm finger 264 (266) of the alarm 
setting cam 258 is provided with a sloped depression 272 (274) and a 
sloped shoulder 276 (278) as shown in FIG. 18. Accordingly, during the 
adjustment of the alarm setting time, these alarm fingers 264 and 266 are 
depressed or shouldered by way of the depressions 272 and 274 and the 
shoulders 276 and 278. Consequently, not only when the alarm setting axle 
232 is rotated clockwise, but also, when it is rotated counterclockwise, 
the alarm setting time can be adjusted. 
Also, as shown in FIG. 18, at a location adjacent to the depression 272 
(274) on the top of the alarm finger 264 (266) of the alarm setting cam 
258, a projection 280 (282) is provided integrally with the alarm finger 
264 (266). On the other hand, at a location adjacent to a depression 284 
(286) of the engaging portion 240 (242) of the alarm setting wheel 238, a 
recess 288 (290) that can engage with the projection 280 (282) is formed. 
Through the engagement between the projection 280 (282) with the recess 
288 (290), the protrusion 246 (248) of the alarm intermediate wheel 244 is 
pressed into a wall surface 292 (294) of the loose joint 260 (262) of the 
alarm setting cam 258. As a result, a high precision in alarm setting 
operation can be obtained. 
The third embodiment according to the present invention has the 
construction as described above. Hereunder, the description will be given 
on its operation. Firstly, a description starting with the operation for 
setting the alarm time will be given. 
As should be clearly seen in FIG. 16, when the alarm setting knob 234 is 
rotated, the alarm setting wheel 238 that is fixed to the alarm setting 
axle 232 is rotated. Also, by interlocking with the alarm setting axle 
232, the alarm setting wheel 236 is rotated. As a result, the alarm 
setting wheel 238 rotates for a predetermined amount against the alarm 
setting cam 258 and is positioned at a rotational position corresponding 
to the desired alarm setting time. At this time, the alarm setting wheel 
238 is clicked by the click lever (not shown in the figures) and thus high 
alarm setting precision can be obtained. 
Thereafter, the adjustment of the set alarming time can be done by rotating 
the alarm setting axle 232 in a clockwise or a counterclockwise direction. 
In other words, as shown in FIG. 18, the alarm finger 264 (266) of the 
alarm setting cam 258 is provided with the depression 272 (274) and the 
shoulder 276 (278). Consequently, the alarm finger 264 (266) that fell 
into the engaging portion 240 (242) can return to the gear surface via the 
depression 272 (274) or the shoulder 276 (278). Accordingly, the alarm 
setting time can be adjusted by the rotation of the alarm setting axle 232 
in a clockwise or a counterclockwise direction. Also, for the time 
adjustment, the same operation as described above can be used. That is, 
the alarm setting cam 258 can be rotated optionally against the alarm 
setting wheel 238 and therefore, the time can be adjusted through rotating 
the alarm setting knob 234 clockwise or counterclockwise. 
As is shown in FIG. 16, when the wheel train of timepiece continues to be 
driven with the alarm setting at the desired alarming time, the ten minute 
wheel 250 that is engaged with the minute hand gear 226 and the second 
hand pinion 252 rotates at a ratio once every ten minutes. Consequently, 
the two hour wheel 254 rotates intermittently at the rate of 30 degrees 
per ten minutes by means of the engagement between the engaging points 
254a provided in the two hour wheel 254 and the intermittent feed teeth 
250a provided in the ten minute wheel 250. Hence, the rotation of the two 
hour wheel 254 is transmitted through the four hour wheel 256 to the alarm 
intermediate wheel 244, and the alarm intermediate wheel 244 continues 
rotation at a rate of once every twelve hours while rotating 
intermittently. 
The alarm setting cam 258 rotates together with the intermittent rotation 
of the alarm intermediate wheel 244, with the loose joint 260 (262) being 
kept in contact with the protrusion 246 (248). At the same time, the alarm 
finger 264 (266) formed in the alarm setting cam 258 approaches the 
engaging portion 240 (242) of the alarm setting wheel 238. However, when 
the frictional force between the alarm intermediate wheel 244 and the 
alarm setting cam 258 is greater than the frictional force between the 
alarm setting wheel 238 and the alarm setting cam 258, the rotation 
continues with the protrusion 246 (248) of the alarm intermediate wheel 
244 not in contact with the wall surface 292 (294) of the loose joint 260 
(262) of the alarm setting cam 258. The time for triggering the alarm 
operation is set to occur when the alarm finger 264 (266) falls into the 
engaging portion 240 (242) while the protrusion 246 (248) is in contact 
with the wall surface 292 (294) of the loose joint 260 (262). 
Consequently, if the alarm finger 264 (266) falls into the engaging 
portion 240 (242) while the protrusion 246 (248) is not in contact with 
the wall surface 292 (294) of the loose joint 260 (262), the alarm 
triggering time is changed from the time set for actuating the alarm. 
In this embodiment, even when the alarm setting cam 258 rotates with the 
protrusion 246 (248) not in contact with the wall surface 292 (294) of the 
loose joint 260 (262) as described above, accurate alarm setting can be 
performed. That is, when it becomes immediately before the time set to 
give the alarming, as is shown in FIG. 18 (A), the projection 280 (282) 
provided in the alarm finger 264 (266) engages with the recess 288 (290). 
At this time, the frictional force between the alarm setting wheel 238 and 
the alarm setting cam 258 becomes greater than the frictional force 
between the alarm intermediate wheel 244 and the alarm setting cam 258. 
Therefore, as shown in FIG. 18 (B), the alarm intermediate wheel 244 
rotates until the protrusion 246 (248) contacts the wall surface 292 (294) 
of the loose joint 260 (262), while the alarm setting cam 258 remains 
stationary. Then when the time set for triggering the alarming operation 
occurs, the alarm intermediate wheel 244 rotates intermittently from the 
state shown in FIG. 18 (B). At this time, as shown in FIG. 18 (C), the 
alarm setting cam 258 rotates being pressed by the protrusion 246 (248) of 
the alarm intermediate wheel 244. Meantime, the projection 280 (282) of 
the alarm finger 264 (266) climbs up from the recess 288 (290) of the 
alarm setting wheel 238 by way of the slope formed in the projection 280 
(282). Then, as is shown in FIG. 18 (D), the alarm setting cam 258 rotates 
until the end of the projection 280 (282) reaches to the depressing 
surface 284 (286) of the engaging portion 240 (242) of the alarm setting 
wheel 238, that is, to the alarm setting time position indicated by the 
dotted line 300. As a result, as shown in FIG. 18 (E), the alarm finger 
264 (266) of the alarm setting cam 258 drops into the engaging portion 240 
(242) of the alarm setting wheel 238 via the depression 272 (274). At this 
time, the movable contact plate 268 comes into contact with the fixed 
contact plate 270. As a result, the alarm operation circuits, such as 
alarm circuit, timer circuit, which are connected to these contact plates 
268 and 270 are actuated. Thereafter, when the alarm intermediate wheel 
244 continues the intermittent rotation, the alarm setting cam 258 rotates 
being pressed by the protrusion 246 (248) of the alarm intermediate wheel 
244. At the same time, the alarm finger 264 (266) returns to the gear 
surface from the engaging portion 240 (242) of the alarm setting wheel 
238, by way of the shoulder 276 (278). At this time, the alarm setting 
wheel 238 presses the movable contact plate 268 against its spring force. 
Consequently, both the contact plates 268 and 270 are released from 
contact, and the alarming operation is completed. 
As described above, in this embodiment, as shown in FIG. 18 (B), 
immediately before the time set for alarming is reached, the condition 
wherein the protrusion 246 (248) of the alarm intermediate wheel 244 is 
pressed towards the wall surface 292 (294) of the loose joint 260 (262) of 
the alarm setting cam 258 can be achieved by means of the engagement 
between the projection 280 (282) and the recess 288 (290). Therefore, as 
shown in FIG. 18 (D), high precision in alarm setting can be obtained. 
In addition, because the alarm intermediate wheel 244 rotates 
intermittently by interlocking with the wheel train of timepiece, the 
depressing operation as shown in FIG. 18 (E) can be performed by means of 
the one intermittent rotation of the alarm intermediate wheel 244 when the 
time set for alarming occurs with the state as shown in FIG. 18 (B). Thus, 
further precise alarm setting can be performed. 
In this embodiment, the foregoing recess 288 is formed to be relatively 
shallow, in order to facilitate the disengagement between the projection 
280 and the recess 288 by the manual operation performed with relatively 
high speed and relatively strong rotational force in a counterclockwise 
rotation of the alarm intermediate wheel 244. 
In the embodiment described above, the projection 280 (282) is provided at 
a location adjacent to the depression 272 (274) at the top of the alarm 
finger 264 (266) of the alarm setting cam 258. Also, in the same 
embodiment, the recess 288 (290) that can engage with the projection 280 
(282) is provided at a location adjacent to the the depression 284 (286) 
of the engaging portion 240 (242) of the alarm setting wheel 238. However, 
it may be constructed also as described below. That is, the projection 
could be provided at a location adjacent to the depression 284 (286), so 
that, by the engagement between the projection and the alarm finger 264 
(266) of the alarm setting cam 258, the projection 246 (248) of the alarm 
intermediate wheel 244 is pressed towards the wall surface 292 (294) of 
the loose joint 260 (262) of the alarm setting cam 258. In this case, it 
is necessary to set the spring force of the movable contact plate 268 to 
have the following effect. That is, the frictional force between the alarm 
setting wheel 238 and the alarm setting cam 258, depending on the 
engagement between the alarm finger 264 (266) and the projection, must be 
stronger than the frictional force between the alarm intermediate wheel 
244 and the alarm setting cam 258. 
Also, it may be constructed as follows. That is, the engaging portion 240 
(242) and the recess 288 (290) of the alarm setting wheel 238 can be 
provided in the alarm setting cam 258, while the alarm finger 264 (266) of 
the alarm setting cam 258 can be formed in the alarm setting wheel 238. 
Furthermore, it is also possible to use the following construction. That 
is, the loose joint 260 (262) of the alarm setting cam 258 can be provided 
in the alarm intermediate wheel 244, while the protrusion 246 (248) of the 
alarm intermediate wheel 244 can be provided in the alarm setting cam 258. 
As has been described in detail in the above, according to the present 
invention, the lowering of the alarm setting precision due to the one side 
drop phenomenon wherein only one of the alarm fingers drops into the 
engaging portion, etc. can be prevented. Also, the alarm setting time, 
etc. can be adjusted by both clockwise and counterclockwise rotation of 
the axle for adjusting the alarm setting wheel. Furthermore, because the 
alarm triggering operation of the alarm finger is performed in the state 
wherein the protrusion of the alarm setting cam is pressed and comes into 
contact with the wall surface of the loose joint of the hour hand wheel, 
remarkably high precision alarm setting can be obtained. Moreover, the 
present invention contributes to bring about economical effects. For 
example, with this simple structure, the lowering in the alarm setting 
precision due to the use over long periods of time can be prevented. Also, 
its manufacturing costs can be cut down significantly.