Quartz crystal wrist watch

A quartz crystal wrist watch wherein means are provided for removably mounting along the periphery of the watch the battery power source, the oscillator and associated circuitry and an electro-mechanical converter. The electro-mechanical converter is provided with a rotor coupled to the gear train of the watch positioned in the central portion thereof. The oscillator and associated circuitry are removably mounted in said watch by means of a resin case adapted to carry said oscillator and associated circuitry.

BACKGROUND OF THE INVENTION 
This invention relates to quartz crystal wrist watches and to the physical 
structure thereof. Quartz crystal wrist watches are generally provided 
with a battery power source, a crystal oscillator which serves as a time 
standard and associated circuitry for converting the output of the 
oscillator to the desired driving signal, an electro-mechanical converter 
responsive to said driving signal such as a pulse motor and indexing 
mechanism, and the drive train of the watch. 
These components must be mounted in a watch so as to provide a compact thin 
structure. Further, although it is more convenience to mount these 
components in a square watch, there is a larger demand for round wrist 
watches, thereby complicating the mounting of these structures into a 
watch case. Thus, the battery power source requires a substantial portion 
of the space of the wrist watch, and being generally round in shape, 
occupies a greater space than its volume would otherwise indicate. 
Further, if other components are mounted above or below the battery, the 
thickness of the watch would be substantially increased. 
The oscillator and associated circuitry includes the crystal oscillator 
generally mounted in a vacuum in a hermetic sealed case provided with a 
shield cap and external lead terminal, an oscillation circuit, a fine 
adjusted mechanism for adjusting the frequency of the oscillator, a 
temperature compensating element, a divider circuit for dividing the 
frequency of the output of the crystal oscillator, and a driving circuit 
for the electromechanical converter. If these components are separately 
mounted, assembly and repair of the watch becomes difficult and expensive. 
Further, the method of mounting these components must avoid frequency 
changes due to stray capacitance and external shock. 
By the compact assembly approach of the invention, the foregoing 
difficulties are solved. 
SUMMARY OF THE INVENTION 
Generally speaking, in accordance with the invention, the components of a 
quartz crystal wrist watch are mounted so that the battery power source, 
the oscillator and associated circuitry and the electro-mechanical 
converter are mounted on the periphery of the watch, with the rotor of 
said electromechanical converter being positioned centrally of said watch 
for cooperative engagement with the drive train of said watch, also 
located in the central portion thereof. The oscillator and associated 
circuitry are removably mounted on said watch by means of a resin case 
provided with grooves therein for receiving the various components. 
Accordingly, the object of the invention is to provide a compact electronic 
crystal wrist watch having a round configuration. 
Another object of the invention is to provide an electronic quartz crystal 
wrist watch incorporating a tuning fork crystal oscillator as the time 
standard having a frequency of more than 16 kHz, oscillation and divider 
circuits including MOS transistors, a driving circuit including integrated 
circuits, and a pulse motor serving as an electro-mechanical converter. 
A further object of the invention is to provide a quartz crystal wrist 
watch wherein the various components thereof are readily connected 
together for ease in after sale service and assembly, and wherein the 
crystal oscillator and the associated circuitry thereof are removably 
mounted as a unit. 
Still another object of the invention is to provide a quartz crystal wrist 
watch having a time standard oscillator not affected by the environment, 
such as external disturbances due to shock or ambient stray capacitance. 
Still other objects and advantages of the invention will in part be obvious 
and will in part be apparent from the specification. 
The invention accordingly comprises the features of construction, 
combinations of elements, and arrangement of parts which will be 
exemplified in the constructions hereinafter set forth, and the scope of 
the invention will be indicated in the claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to FIG. 1, wherein an equivalent circuit diagram of the time 
standard oscillator and associated circuitry of the watch according to the 
invention is depicted, crystal oscillator 1 is shown coupled to an 
oscillation circuit 2, in part through a stepped variable condenser 3 for 
adjusting the frequency of the oscillator and a temperature compensating 
element 4. A resin case for receiving the oscillator and its associated 
circuitry is shown schematically by dashed line 5, said associated 
circuitry including a divider circuit 6 for reducing the frequency of the 
output signal of the oscillator and a driving circuit 7 for driving the 
motor or other electromechanical converter. 
Referring now to FIG. 2, the time standard oscillator and associated 
circuitry is shown mounted on a resin case 8 which may be formed, for 
example, from an eleastic resin having thermosetting properties, which 
resin case is in turn mounted in the quartz crystal wrist watch according 
to the invention. The time standard crystal oscillator is mounted within a 
cylindrical crystal oscillator casing 9a. The crystal oscillator is 
mounted within said casing on a stem, and is provided with three external 
lead terminals 10. Casing 9a is evacuated, and is sealed hermetically. 
The crystal oscillator utilized as time standard may be a tuning fork 
crystal oscillator having a frequency of more than 16 kHz. An alternate 
type of oscillator is a leaf spring oscillator, which is advantageous for 
mass production, but requires 23 mm in length where a frequency of 16 kHz 
is required, and where resistance to outside shocks is required. A leaf 
spring oscillator of less than 23 mm in length is substantially affected 
by the suspension wire and may not be used as a time standard source in a 
wrist watch. The length of the leaf spring oscillator is even further 
increased to about 28 mm when it is suspended within a hermetically sealed 
case by a shock resistant mounting. For the foregoing reasons, the leaf 
spring oscillator is not particularly adapted for use in compact and round 
wrist watch movements, and accordingly, the tuning fork oscillator is 
preferred. Said tuning fork oscillator may be only 13 mm in length, and 
may be specially mounted and sealed hermetically within a cylindrical 
metal case of only 16 mm in length. 
The crystal oscillator casing 9a is provided with a cap 9b on the external 
lead terminal portion thereof in order to minimize the effect of stray 
capacitance between said external lead terminals and other portions of the 
circuitry. The lead wires pass through windows in portions of said cap, 
but the crystal oscillator is shielded. The temperature compensating 
element 11 is formed of BaTiO.sub.3 and is wired to other lead elements by 
a terminal plate 12. 
Also mounted on resin case 8 is a stepped variable condenser for fine 
adjustment of frequency of said oscillator. Said condenser consists of a 
group of condensers formed on a glass substrate 13 by vacuum evaporation. 
A contact spring 14 is mounted on said resin plate by means of screw 15 
above said glass substrate. The separate condensers deposited on substrate 
13 can be selectively added to or removed from the circuit to determine 
the total capacitance thereof by means of a group of pins 16 which 
selectively engage one of the fingers of contact spring 14 to bring said 
finger into engagement with the corresponding capacitor on the substrate. 
In other words, the fingers of contact spring 14 may be selectively 
brought into and out of engagement with the capacitors on substrate 13 by 
inserting or removing pin 16. 
The oscillation circuit, divider circuit and driving circuit, formed from 
MOS transistor components and integrated circuits, are mounted on the 
opposed side of resin case 8 opposite substrate 13. Said components are 
retained within the resin case by means of an epoxy resin which protects 
said components from outside influences such as moisture. Said electronic 
circuits include a 15-stage flip-flop divider circuit for dividing the 
frequency of the output of the oscillator circuit and a reset circuit. 
Both the oscillation and divider circuits may be formed of hybrid 
integrated circuits, but if MOS circuits are utilized, both the 
oscillation and divider circuits can be incorporated in about a 2 mm 
square space. Even with the use of epoxy resins, by using MOS circuits, 
the space required for the oscillation and divider circuitry can be 
reduced by from one-half to one-third, as compared with the space required 
by conventional type of circuits using only integrated circuits. The lead 
terminals of the electric circuits mounted below the resin case 8 are 
electrically connected to the components above said resin case by means of 
screws and pin connectors, as well as a group of lead terminals 18 
preferably formed as thin plates. The top surface of the resin case may be 
enclosed by a metal holder 19 which serves as a shield plate for the 
capacitors on substrate 13, and as a retention device for contact spring 
15, pin 16 and crystal oscillator 9a. 
Referring now to FIGS. 3 and 4, we see that the top surface of resin case 8 
is formed with a channel 20 for receiving the crystal oscillator 9, a 
channel 21 for receiving the stepped variable condenser substrate 13, and 
a channel 23 for receiving the temperature compensating element 11. The 
back of resin case 8 is provided with a channel 22 for receiving the 
oscillation and divider circuits 17a, the driving circuit 17b which is 
coupled to an electro-mechanical converter, silicon 17c for protecting the 
circuits, and an epoxy resin 17d for retaining said components together. 
The channel 21 for receiving the stepped variable condenser substrate and 
channel 22 for receiving the electric circuits are positioned in 
overlapping relation on opposed sides of the resin case. 
Accordingly, it is seen that the components of the crystal oscillator and 
its associated circuitry are all mounted on resin case 8 for removal from 
and mounting in the quartz crystal watch case according to the invention 
as a unit. The structure is extremely compact, occupying from about 
one-third to about one-fifth of the volume of the available space in the 
watch. The foregoing arrangement greatly enhances both the initial 
manufacture and the aftersale maintenance of the watch, since the entire 
time standard oscillator assembly can be replaced as a unit, and can be 
worked on outside of the watch. The structure is particularly shielded to 
prevent the adverse effect of stray capacitance on the oscillator. 
Further, the crystal oscillator is firmly mounted within the resin case 
which is elastic, and therefore assists in shock resistance. 
Referring now to FIG. 5, the quartz crystal watch depicted therein is 
provided with a stem 31 disposed at the position of 12 O'clock, on a round 
plate 32. A battery 33 is mounted on said plate at about 3 O'clock. As 
noted above, the battery is round but is positioned at the periphery of 
the watch. A negative pulse terminal plate 34 connects the battery 33 to 
the oscillator circuitry which is mounted on resin case 35. Said resin 
case is similar to the resin case 8 described above, in that it supports 
all of the components of the oscillator and associated circuitry for 
removable mounting on plate 32. The crystal oscillator casing 36 
containing the crystal oscillator is disposed in a channel on the top 
surface of resin case 35. Fine adjustment of the frequency of the 
oscillator is provided by stepped condenser 37 similar in structure to the 
condenser 13, 14, 15 and 16 of FIGS. 2 and 4. Also mounted on the resin 
case is the temperature compensating device 38. The electronic circuitry 
39 is fixed on the opposed side of resin case 35 opposite the stepped 
condenser. The input and output terminals of said electronic circuitry 
include electrical signal terminal 40a for applying the driving signal to 
the pulse motor which serves as the electromechanical converter. These 
terminals all extend from one of the electronic circuitry, namely the side 
on which said pulse motor is positioned. The remaining terminals all 
extend from the opposed side of the electronic circuitry. Specifically, 
terminals 40c are connected to the crystal oscillator, terminal 40d is 
connected to the negative pulse terminal 34 of the battery, and terminal 
40e is a reset terminal. The latter terminals are all positioned on the 
side of the electronic circuitry adjacent the battery. The output and 
input terminals of the tuning fork crystal oscillator 41 are also disposed 
on the battery side of the oscillator case 36, in order to simplify the 
terminal connection with the circuitry. Leads 42 are provided for 
connecting the stepped condenser and temperature compensating device. 
Coupled to the electrical circuitry 39 by leads 40a is the 
electro-mechanical converter 43a which converts the electrical output 
signal from said circuit into rotary movement of the gear train of the 
watch. Said electromechanical converter includes a coil 13a formed from 
copper wire having 2.5/100.phi. mm, which wire is wound in about 15,000 
turns on a coil core formed of magnetic material. Coil 43a defines the 
driving coil of the pulse motor and is substantially cylindrical in shape. 
The output signal from said circuit consists of an alternating pulse 
train, one pulse of which is applied to said driving coil each second. The 
magnetomotive force generated in the coil is applied to stators 43b and 
43c to rotate a rotor 44 in predetermined angular increments. The rotor 44 
may be made of Pt CO material and is provided with six poles formed 
alternately as north and south poles. 
The above described pulse motor is utilized in place of the conventional 
pallet-fork escapement as an electro-mechanical converter, since said 
pallet-fork escaptement occupies too large an area, and would preclude the 
provision of a round compact wrist watch. Thus, the pallet-fork escapement 
has an outer diameter of about 5.about.7.phi.mm, while the outside 
diameter of the pulse motor is only about 3.phi.mm. However, the 
cylindrical shape of the driving coil 43a precludes the mounting of any 
components above or below said coil, where a thin wrist watch is desired. 
Accordingly, said driving coil is positioned on the periphery of the watch 
according to the invention. 
Rotor 44 is rotated by the magnetomotive force and its rotating energy is 
transmitted to a fourth wheel 45 of the watch gear train, which in turn in 
operatively coupled to the gear train third wheel and center wheel for 
driving same. A second hand jumper 46 is coupled to fourth wheel 45 for 
indexing the position of the second hand. A regulating lever 17 for the 
operation of said second hand is also positioned in the central region of 
the watch, one end of said regulating lever being engaged with stem 31, 
the other end of said regulating lever being engaged with the end of 
jumper 46 for manipulating said jumper. 
The quartz crystal wrist watch according to the invention consists of a 
plurality of components arranged on a round plate in such manner that the 
stem is favorably disposed near the 12 O'clock position, the battery is 
disposed near the 3 O'clock position, the time standard oscillator and 
associated circuitry are formed as a unit and positioned adjacent the 
battery, and the driving coil of the pulse motor is disposed between the 
time standard oscillator and the stem. Said battery, time standard 
oscillator and associated circuitry and pulse motor driving coil are 
positioned along the periphery of said round plate. The regulating 
mechanism, along with the drive train of the watch are positioned in the 
central region of the watch, whereby overlapping relation between the 
larger components is avoided. 
Reference is now made to FIGS. 6 and 7 wherein a stepping motor assembly is 
provided enabling the thickness of the electronic timepiece depicted in 
FIG. 5 to be further diminished, like reference numerals being utilized to 
depict like elements. Specifically, the stepping motor mechanism, 
generally indicated at 60 in FIG. 6, and the gear train mechanism, 
generally indicated at 62 in FIG. 7 allow both such assemblies to be 
contained within the plate of the wrist watch thereby providing for a 
thinner wrist watch mechanism. This is achieved by placing the coil and 
rotor in the same plane in the manner hereinafter discussed. 
It is noted that in electro-mechanical converters such as stepping motors, 
a driving coil is normally wound about the stator and a rotor is disposed 
inside the coil and is rotated by the stator coil. Such configuration 
results in a unitary motor which is easily disengageable from the 
timepiece. However, such motors cause sharp increases in the thickness of 
the timepiece thereby rendering same not suited for thin, small sized 
round wrist watches. 
Accordingly, as is particularly depicted in FIGS. 6 and 7, the coil 43a is 
wound about a coil core 56 which is coupled to yokes 43b and 43c, which 
yokes act as stators and are disposed in the same plane as rotor 44. The 
rotor 44 is mounted on shaft 44a, which is supported by gear train bridge 
58 which bridge also supports the shafts of gear train members including 
fourth wheel 45 and third wheel 54. Thus, because the rotor shaft 44a and 
the coil 43a have about the same height, the thickness of the timepiece 
can be reduced to the order of the coil. Furthermore, by merely removing 
bridge 58, it is easy to remove the rotor 44 and the entire gear train if 
it is desired to fix same. The stator defined by coil core 56 and yokes 
43b and 43c can likewise be separately removed from plates 32. 
Accordingly, by providing yokes for the stator and a bridge member as 
depicted in FIGS. 6 and 7, a thinner round electromechanical wrist watch 
is provided. 
The foregoing arrangement provides for simplified terminal connections and 
for a round, particularly flat watch movement. Further, three major 
components of the watch, specifically the battery power source, the 
oscillator and associated circuitry and the mechanical components of the 
watch, may be readily separated, with the function of each block being 
separately adjustable. This feature, which permits the removal of 
components by merely removing selected screws, is particularly 
advantageous to after-sales service. Further, this arrangement is also 
particularly adapted for mass production. 
It will thus be seen that the objects set forth above, and those made 
apparent from the preceding description, are efficiently attained and, 
since certain changes may be made in the above constructions without 
departing from the spirit and scope of the invention, it is intended that 
all matter contained in the above description or shown in the accompanying 
drawings shall be interpreted as illustrative and not in a limiting sense. 
It is also to be understood that the following claims are intended to cover 
all of the generic and specific features of the invention herein 
described, and all statements of the scope of the invention which, as a 
matter of language, might be said to fall therebetween.