Switching device for battery powered alarm clock

In a battery powered alarm clock, an alarm switching device comprises at least one detecting wheel whose phase is set in accordance with the desired alarm time, at least one detecting switch which is closed when the phase of the time wheel of the clock corresponds to that of the detecting wheel and a printed circuit board having alarm circuitry mounted thereon with at least one land for connecting the alarm circuitry to one pole of the battery. The alarm switching device construction provides solderless connection by at least two battery contact plates for contacting the two poles of the battery. One of the plates provides three electrical contacts including a first contact with one pole of the battery, a second contact with the land on the printed circuit board and a third contact with the detecting switch, whereby the assembly and construction of the clock is greatly simplified.

BACKGROUND OF THE INVENTION 
This invention relates to an alarm clock including a battery powered 
electromechanical transducer for driving a gear train which actuates an 
electric alarm signaling device at a predetermined alarm signaling time. 
In assembling conventional alarm clocks of this type, it is the usual 
procedure to connect with lead wires the electric circuit, time detecting 
switches, battery and the buzzer which are disposed independently of each 
other. This construction has the disadvantages that it requires too many 
lead wires so that extra space for wiring and extra assembling steps for 
soldering those lead wires is necessary and that it is difficult to fix 
due to the complicated wiring. 
SUMMARY OF THE INVENTION 
The object of this invention is to overcome the disadvantages of the 
conventional alarm clocks. 
The object is attained by providing detecting wheels the phases of which 
are determined dependent upon the alarm signaling time setting, time 
wheels, detecting switches which are closed when the phases of the afore 
mentioned wheels are synchronized, and at least two contact plates 
connected to the clock battery, a part of the plates being a common 
terminal for the detecting wheels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to FIGS. 1 to 3, inclusive, an explanation will be made of 
the first embodiment of the invention. 
A case (1) molded of plastics has a projection (1a) on its left end and 
rotatably receives a tubular boss (17c) of an hour detecting wheel 17 and 
the shaft of an alarm signaling time setting wheel (18). 
A middle frame 2 molded of plastics rotatably guides a minute wheel (9) and 
slidably guides an alarm setting push button (23). 
A cover (3) molded of plastics rotatably guides a spindle (6) and the alarm 
signaling time setting wheel (18), and frictionally guides the alarm 
setting push button (23). A screw (4) fastens the cover (3) and the middle 
frame (2) to the case (1) at the projection (1a) of the case (1). 
The following explanation is concerned with the gear train for time 
indication for the embodiment of FIGS. 1-3. 
A second wheel (5) driven by an electromechanical transducer, not shown, is 
fixedly mounted on the spindle (6), spindle 6 also penetrates through a 
tubular boss (9b) of a minute wheel (9) and is provided with the second 
hand (33) at the tip thereof. The second wheel (5) is engaged with the 
minute wheel (9) indirectly through an intermediate wheel (not shown) 
having frictional coupling means, not shown, disposed there between. The 
minute wheel (9), a pinion (9a) and the tubular boss (9b) are molded of 
plastics in one body. 
The tubular boss (9b) penetrates an hour wheel (12) and is provided with 
the minute hand (10) at the tip. The pinion (9a) is engaged with the hour 
wheel (12) through an intermediate hour wheel, not shown. 
The hour wheel (12) and the tubular boss (12a) are molded of plastics in 
one body. The hour hand (13) is fixed at the tip of the tubular boss 
(12a). 
The following explanation is concerned with the construction of the gear 
train for alarm signaling for the first embodiment of the alarm clock. 
A minute detecting wheel (16) made of an electrically conductive material 
is rotatably fitted on the tubular boss (9b) between the minute wheel (9) 
and the hour wheel (12). An index (34) is fixed at the tip of a tubular 
boss (17c) fixedly assembled with an hour detecting wheel (17) made of an 
electrically conductive material. 
An alarm signaling time setting wheel (18) comprises, in one body, of a 
first wheel (18a) and a second wheel (18b) engaged with the minute 
detecting wheel (16) and the hour detecting wheel (17), respectively, and 
a third wheel (18c). An alarm signaling time setting knob (19) is fixed to 
the alarm signaling time setting wheel (18) at the tip thereof. A 
clickstop spring (29) is fixed on the bottom surface of the middle frame 
(2) by a screw (40) and the tip thereof is engaged with the third wheel 
(18c) of the alarm signaling time setting wheel (18) causing the alarm 
signaling time setting wheel to effect a click-stop motion. 
The following explanation is concerned with the construction of the alarm 
signaling time detecting device of the alarm clock of the first 
embodiment. 
Referring first to FIG. 3, a negative contact plate (35) and a positive 
contact plate (36) are connected to the negative and the positive 
terminals, respectively of a battery (E), respectively. The negative 
contact plate (35) has a conductive part in the form of a first elongation 
(35a) extending to the center of the clock and another conductive part in 
the form of a second elongation (35b) at the left end of the clock with a 
tapped hole. The positive contact plate (36) has a raised part (36a) with 
a tapped hole at the left end of the clock. 
A driving coil (L) of an electromechanical transducer, not shown, a buzzer 
(B) and a control circuit (C) are disposed on the surface of a printed 
circuit board (37), on the other side of which there is printed a pattern 
of an electric circuit for electrically connecting the abovementioned 
elements. A negative pattern (37a) and a positive pattern (37b) are 
connected to the terminals of the control circuit (C). The control circuit 
(C) controls the electric current for the driving coil (L) and the buzzer 
(B). A switch pattern (37c) is connected to the alarm terminal of the 
buzzer (B). 
The buzzer (B) of this embodiment is actuated when the switch pattern (37c) 
and the negative pole of the electric power source are connected. The 
buzzer stop push button (23) which is movable between the On and Off 
positions has a working finger (23a) extending through the middle frame 
(2). A stationary contact plate (28) is fixed on the middle frame, with 
the right end (28b) always in sliding contact with the minute switch plate 
(27) and the left end (28a) extending under the switch pattern (37c) of 
the printed circuit board. The left end (28a) of the stationary contact 
plate is spring biased so as to be in contact with the switch pattern 
(37c). The working finger (23a) breaks the contact of the stationary 
contact plate (28) with the switch pattern (37c) when the buzzer stop push 
button (23) is pushed in to the Off position. 
Referring again to FIG. 1, the hour detecting wheel (17) has a first 
projection 17a on the bottom surface and second projections (17b) on the 
upper surface disposed on different circles of different radii at equal 
angular intervals. 
The negative contact plate (35) and the hour detecting wheel 17 are always 
connected electrically as the first projection (17a) is always in contact 
with the first elongation (35a) of the negative contact plate 35. 
The hour switch plate (24) fixed on the hour wheel (12) has an upwardly 
extending slide contact piece (24a) and downwardly extending projections 
(24b) which project through the hour wheel and are disposed on different 
circles of different radii at equal angular intervals. The ends of the 
projections (24b) are almost in the plane of the bottom surface of the 
hour wheel (12). The phases of the second projections (17b) of the hour 
detecting wheel and the projections (24b) of the hour switch plate are 
synchronized once in twelve hours so that the hour detecting wheel 17 and 
the hour wheel 12 are electrically connected once in twelve hours. The 
hour switch plate 24 and the minute detecting wheel 16 are always in 
electrical contact as the slide contact piece (24a) is always in sliding 
contact with the bottom surface of the minute detecting wheel (16). An 
insulating disk (25) is made of an electrically nonconductive material. A 
sectoral switch plate (26) made of an electrically conductive material is 
formed in a planar shape as shown in FIG. 2. 
The minute detecting wheel (16) and the sectoral switch plate (26) are 
joined with the insulating disk (25) in between by means of caulking so 
that the sectoral switch plate (26) and the minute detecting wheel (16) 
are electrically connected. A minute switch plate (27) having a downwardly 
extending slide contact piece (27a) is fixed on the minute wheel (9). The 
slide contact piece (27a) is normally in sliding contact with the 
insulating disk (25) and comes into electrical contact with the sectoral 
switch plate (26) once every hour. The right end (28b) of the stationary 
contact plate (28) is always in contact with the upper surface of the 
minute switch plate (27). 
The following explanation is concerned with the operation of the first 
embodiment of the invention. 
An alarm signaling time is set by the alarm signaling time setting knob 
(19). In this alarm signaling time setting procedure, the phases of the 
minute detecting wheel (16) and the hour detecting wheel (17) are 
determined so that the phases of the sectoral switch plate (26) and the 
second projections (17b) of the hour detecting wheel are determined at the 
same time. The left end (28a) of the stationary contact plate is 
electrically connected with the switch pattern (37c) by putting the buzzer 
stop button (23) in the On position. 
Although the buzzer stop button 23 is turned on, the buzzer (B) will not be 
actuated because the sectoral switch plate (26) and the minute switch 
plate (27) or the hour detecting wheel (17) and the hour switch plate (24) 
have not yet been electrically connected. Although the minute detecting 
wheel (16) and the hour detecting wheel (17) are urged to turn due to the 
rotation of the hour switch plate (24) and the minute switch plate (27), 
they remain at the predetermined phases constrained by the click-stop 
spring (29) working on the alarm signaling time setting wheel (18). The 
minute switch plate (27) and the sectoral switch plate (26) come in 
contact once an hour, however, the buzzer will not be actuated before the 
hour wheel (12) reaches the predetermined phase. As time passes, in the 
first place the phases of the projections (24b) of the hour switch plate 
24 and the second projections (17b) of the hour detecting wheel 17 are 
synchronized so that the hour switch plate 24 and the hour detecting wheel 
17 are electrically connected. And while this connection is maintained, 
the slide contact piece (27a) of the minute switch plate and the sectoral 
switch plate (26) come into electrical contact. 
Thus when those electrical contacts are made simultaneously, the buzzer is 
actuated in a series electric circuit comprising the negative contact 
plate (35)--the hour detecting wheel (17)--the hour switch plate (24)--the 
minute detecting wheel (16)--the sectoral switch plate (26)--the minute 
switch plate (27)--the stationary contact plate (28)--the switch pattern 
(37c). 
The buzzer can be stopped by putting the buzzer stop button (23) in the OFF 
position to disconnect the left end (28a) of the stationary contact plate 
and the switch pattern (37c). 
Referring now to FIG. 4, an explanation will be made of the second 
embodiment of the invention. 
An upper cover (103) and a bottom cover (130) are assembled on to a middle 
frame (102), being fixed at the projection (102a) of the middle frame 
(102) by means of a screw (104). A gear train for time indication 
comprises, similarly to that of the first embodiment, a second wheel 
(105), an intermediate wheel provided with a frictional coupling 
mechanism, not shown, a minute wheel (109), an intermediate hour wheel 
(111) and an hour wheel (112). 
The gear train for the alarm signaling device comprises a second minute 
wheel (141) engaged with the intermediate hour wheel (111) and rotating at 
the same rate as the minute wheel (109), a minute detecting wheel (125) 
disposed under the second minute wheel (141), an hour detecting wheel 
(117) disposed between the hour wheel (112) and the bottom cover (130) and 
provided with an index (132) at the tip of its tubular boss (117c), an 
alarm signaling time setting wheel (118) comprising a first wheel (118a) 
engaged with an idle wheel (134) and a second wheel (118b) engaged with 
the hour detecting wheel (117) and an alarm signaling time setting knob 
(9) fixed at the tip of its spindle. A friction breaking piece (133) is 
fixed to the middle frame (102) at one end and is pressed against the 
upper surface of the first wheel (118a) at the other end to provide a 
uniform frictional torque on the alarm signaling time setting wheel (118). 
The following explanation is concerned with the alarm signaling time 
detecting mechanism of the second embodiment. 
A first elongation (135a) is provided which is a part of the negative 
contact plate connected to the battery. 
A stationary contact plate (128) is connected to the switch pattern of a 
printed circuit board by one of its terminals, not shown. 
The other terminals are shaped in three forked elongations and are spring 
biased downwardly so that a first elongation (128d) and a second 
elongation (128e) are pressed against the hour wheel (112) and the second 
minute wheel (141), respectively, and a central third elongation (128f) 
extends downwardly so that it can come into contact with the first 
elongation (135a) of the negative contact plate. 
A projection (112a) is provided on the bottom surface of the hour wheel 
(112). The hour detecting wheel (117) has a hole (117a) at the position 
corresponding to the projection (112a). 
The phases of the projection (112a) and the hole (117a) are synchronized 
once in twelve hours allowing the projection (112a) to fit into the hole 
(117a) so that the hour wheel (112) is pushed down by the spring (128). A 
projection (141a) is provided on the bottom surface of the second minute 
wheel (141). The minute detecting wheel (125) has a hole (125a) at the 
position corresponding to the projection (141a). The phases of the 
projection (141a) and the hole (125a) are synchronized once an hour 
allowing the projection (141a) to fit into the hole (125a) so that the 
second minute wheel is pushed down by the spring (128). 
The following explanation is concerned with the operation of device of the 
second embodiment. 
The minute detecting wheel (125) and the hour detecting wheel (117) are 
rotated by the alarm signaling time setting knob (119) through the wheels 
(118a) and (118b) of the alarm signaling time setting wheel and the idle 
wheel (134) to bring the holes (125a) and (117a) of the minute detecting 
wheel (125) and the hour detecting wheel (117), respectively, to the 
phases corresponding to the alarm signaling time. One terminal 128a of the 
stationary contact plate (128) and the switch pattern of the printed 
circuit board are connected by putting the to alarm stop button in On 
position. 
At this initial moment, the buzzer (B) will not be actuated because the 
hour wheel (112) or the second minute wheel (141) has not come in to the 
phase corresponding to the alarm signaling time and the hour wheel (112) 
or the second minute wheel (141) is not pushed down by the spring (128) to 
make electrical connection. When the hour wheel (112) and the second 
minute wheel (141) come into the phases corresponding to the preset alarm 
signaling time, the projections (112a) and (141a) are brought directly 
above the holes (117a) and (125a), respectively, allowing the hour wheel 
(112) and the second minute wheel (141) to move downwardly as a result of 
being pressed by the spring (128) and at the same time, allowing the 
spring (128) itself to go downwards so that the third elongation (128c) 
comes into contact with the first elongation (135a) of the negative 
contact plate. Thus the alarm signaling circuit being completely closed, 
the buzzer is actuated. 
Any explanations concerning the operation of the other mechanisms of the 
device will be omitted since they are quite similar to that of the first 
embodiment. 
Although the alarm signaling time is detected by the hour and the minute in 
the two preferred embodiments, the minute's place of the alarm signaling 
time may be detected by means of the intermediate hour wheel, or in a 
modification, the alarm signaling time detecting mechanism may detect the 
hour's place omitting detection of minute's place. 
It is also understood that the object of the invention is substantially 
attained by the device as described above, and furthermore, the assembling 
is considerably simplified by elimination of wiring and soldering so that 
the possibility of producing inferior clocks is reduced. Still further, 
the object of the invention is more fully attained by providing, as 
described in the first embodiment, the battery terminal contact plates 
with elongations which are directly connected with the power source 
pattern of the printed circuit board.