U.S. patent application number 09/788606 was filed with the patent office on 2001-09-27 for electric shaver.
Invention is credited to Furuichi, Takeji, Muraguchi, Katsumi.
Application Number | 20010023538 09/788606 |
Document ID | / |
Family ID | 27342462 |
Filed Date | 2001-09-27 |
United States Patent
Application |
20010023538 |
Kind Code |
A1 |
Muraguchi, Katsumi ; et
al. |
September 27, 2001 |
Electric shaver
Abstract
An electric shaver comprises an inner case which retains an
electronic part board 5 and an outer casing which retains a plug
pin board which secures a plurality of plug pins. The inner case is
fabricated of a plastic integral with a bottom wall. The electronic
part board is disposed above the lower separating wall while the
plug pin board is disposed under the lower separating wall. Metal
pins penetrating the lower separating wall connects the electronic
part board and the plug pin board. The bottom opening of the outer
casing is closed with a bottom cover. The bottom cover has a pair
of through holes through which extend outwardly a pair of plug
pins. An electric shaver comprises an inner case which retains an
electronic part board 5 and an outer casing which retains a plug
pin board which secures a plurality of plug pins. The inner case is
fabricated of a plastic integral with a bottom wall. The electronic
part board is disposed above the lower separating wall while the
plug pin board is disposed under the lower separating wall. Metal
pins penetrating the lower separating wall connects the electronic
part board and the plug pin board. The bottom opening of the outer
casing is closed with a bottom cover. The bottom cover has a pair
of through holes through which extend outwardly a pair of plug
pins.
Inventors: |
Muraguchi, Katsumi;
(Aiharanishi, JP) ; Furuichi, Takeji; (Sumoto-shi,
JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
27342462 |
Appl. No.: |
09/788606 |
Filed: |
February 21, 2001 |
Current U.S.
Class: |
30/43.92 ;
30/45 |
Current CPC
Class: |
Y10S 30/01 20130101;
H05K 5/0247 20130101; B26B 19/02 20130101 |
Class at
Publication: |
30/43.92 ;
30/45 |
International
Class: |
B26B 019/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 29, 2000 |
JP |
053346/2000 |
Feb 23, 2000 |
JP |
046537/2000 |
Feb 29, 2000 |
JP |
054822/2000 |
Claims
What is claimed is:
1. An electric shaver comprising: a) an electric motor for
reciprocating an inner blade assembly; b) a battery for the
electric motor; c) an electronic part board connected to the
battery; d) an inner case having an lower separating wall, the
inner case retaining the electronic part board and the electric
motor; e) an outer casing containing the inner case at fixed
position tightly contacting with the lower separating wall, the
bottom opening of which being closed with a bottom cover; f) a plug
board securing a plurality of plug pins extending outwardly from
the outer casing; and g) a plurality of metal pins being inserted
into penetration hole defined at the lower separating wall so as to
secure to the inner case at a fixed position, connected at one end
thereof to the electronic part board and at the other end to the
plug board, wherein the bottom cover is provided with a plurality
of through holes through which extend the plug pins outwardly to
the outer casing to allow access from outside.
2. An electric shaver recited in claim 1, wherein the outer casing
is fabricated of a plastic in a tubular configuration.
3. An electric shaver recited in claim 1, wherein the lower
separating wall is provided with an O-ring at its periphery to
obtain a watertight contact with the internal surface of the outer
casing.
4. An electric shaver recited in claim 1, wherein the bottom cover
is provided with an O-ring at its periphery to obtain a watertight
contact with the internal surface of the outer casing.
5. An electric shaver recited in claim 1, wherein each of the plug
pins is provided with an O-ring abutting on the internal surface of
the bottom cover to obtain a watertight contact with the through
hole for the plug pins.
6. An electric shaver recited in claim 1, wherein a safety valve is
provided on the bottom cover, which safety valve being capable of
opening at a predetermined pressure level.
7. An electric shaver recited in claim 6, wherein the lower
separating wall has an O-ring at its periphery to obtain a
watertight contact with the outer casing, the bottom cover having
an O-ring at its periphery to obtain a watertight contact with the
outer casing, each of the plug pins having an O-ring abutting on
the internal surface of the bottom cover to obtain a watertight
contact with a through hole for the plug pins, the bottom cover
being provided with a safety valve capable of opening at a
predetermined pressure level.
8. An electric shaver recited in claim 1, wherein the inner case
fabricated of a plastic is provided with a plurality of integral
holding latches.
9. An electric shaver recited in claim 1, wherein each of the metal
pins is connected by means of soldering at one end thereof on the
electronic part board and at the end on the plug board.
10. An electric shaver recited in claim 1, wherein the inner case
is provided with a tubular case for retaining two of the batteries
disposed side-by-side and parallel to the electronic part board, in
which the two batteries are to be retained.
11. An electric shaver recited in claim 10, wherein the inner case
has a plurality of support members for supporting the bottom cover,
the support members being disposed on the bottom end of the inner
case at spaces between two cylindrical ones of the batteries.
12. An electric shaver recited in claim 10, wherein the upper end
of the tubular case is closed while the bottom end thereof is
open.
13. An electric shaver recited in claim 12, wherein the two
batteries are retained in the tubular case by means of lead plates
abutting on one of the battery poles and a plug pin.
14. An electric shaver recited in claim 1, wherein the electric
motor and the battery are mounted within the inner case, separated
from each other by a room in the inner case, the inner case being
fixed to the electronic part board on one side thereof to admit
heat-generating parts mounted on the electronic part board in the
room.
15. An electric shaver recited in claim 14, wherein the inner case
is fabricated of a plastic integral with the tubular case, the
upper end of which is closed with the separation wall.
16. An electric shaver recited in claim 14, wherein the
heat-generating parts which are mounted protruding on the
electronic part board are admitted into the room.
17. An electric shaver recited in claim 14, wherein the
heat-generating part is either a charging resistor connected in
series with the battery or a semiconductor switching element for
controlling charging and discharging operations, or a power source
transformer for charging the batteries.
18. An electric shaver recited in claim 1, wherein the bottom cover
has a chamber having a separation wall disposed in the chamber
between the plug pins.
19. An electric shaver recited in claim 18, wherein a power source
plug is provided, which is to be inserted into the chamber of the
bottom cover, having a recess to receive the separation wall when
the plug is inserted into the chamber.
20. An electric shaver recited in claim 18, wherein the separation
wall joins an internal wall of the chamber at one end while is
separated from an internal wall at the other end by a gap which
communicates with a valve hole of a safety valve provided at the
bottom of the chamber.
Description
[0001] This application is based on applications No. 053346/2000
filed in Japan on Feb. 29, 2000, No. 046537/2000 filed in Japan on
Feb. 23, 2000 and No. 054822/2000 filed in Japan on Feb. 29, 2000,
the contents of which incorporated hereinto by references.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an electric shaver having a
circuit board with electronic parts thereon, and a pair of plug
pins projecting from the body casing.
[0003] There are two types of electric shaver, i.e. the one having
built-in wire, and the other having detachable electrical wire.
[0004] The latter must be provided with a plug pins protruding from
the body casing in order to detachably connect a power source
electric wire.
[0005] Shavers of prior art have a pair of plug pins secured on a
plug board and the plug board is firmly retained in the casing so
as to secure the plug pins to the body casing.
[0006] The plug board needs a set of lead wires connected to the
plug pins. Related art shavers have a circuit board provided with
electronic parts as well as a plug board, electrically connected to
each other but separately secured in the body casing.
[0007] The structure of the related art shavers has the drawbacks
that assembling work takes a lot of time because the electronic
parts board and the plug board together with electrical wires
connecting these boards must be placed into the casing.
[0008] The structure has also incurs a higher manufacturing cost
because of a rather complicated configuration of the casing due to
the fact that the casing must be so configured as to receive the
part board and the plug board separately.
[0009] Further there are washable electric shavers. This type of
electric shaver is convenient because the use can wash it.
Waterproof electric shaver requires a watertight casing. Watertight
structure is easily produced by employing a cylindrical body
casing. With a cylindrical casing, watertight structure is readily
achieved by employing watertight sealing means on the upper and
lower end of the casing. However, a cylindrical casing makes it
difficult to insert a part board and a plug board, electrically
connected to each other by means of electrical wires. Mounting
these boards in a cylindrical casing can be facilitated by
employing an outer casing and an inner case to be inserted in the
outer casing, on which inner case part board and plug board are
mounted.
[0010] The electric shaver with the structure has the part board
secured to the inner case, the part board being electrically
connected by means of lead wires of the plug board.
[0011] The electric shaver of the structure requires the assembling
work in which the part board and plug board are inserted together
with electrical wires connecting the boards, which electrical wires
cause troubles.
[0012] In the case where the part board and the plug board are
separately secured to the inner case, the configuration of the
inner case becomes so complicate that it requires a higher
production cost.
SUMMARY OF INVENTION
[0013] The present invention is proposed to overcome these
drawbacks. The most important object of the present invention is to
propose an electric shaver having a simple structure and yet easy
to assemble with a part board and plug board secured on the inner
case.
[0014] Another important object of the present invention is to
provide an electric shaver with a plug board firmly secured to the
inner case on which plug board are fixed plug pins.
[0015] The above and further objects and features of the invention
will be more fully be apparent from the following detailed
description and accompanying drawings.
[0016] The electric shaver of the present invention includes an
electric motor for reciprocating inner blade assembly, batteries
for supplying power to the motor, an electronic part board
connected to the batteries, an inner case securing the electronic
part board, the electric motor and the batteries and inserted into
an outer casing, and a plug pin board securing the plug pins
protruding from the outer surface of the outer casing.
[0017] Furthermore, the electric shaver of the present invention
has the construction described below.
[0018] The inner case has a lower separating wall integral
therewith and made of a plastic, the periphery of which sealingly
abuts on the inner surface of the outer casing. The inner case
secures an electronic part board above the lower separating wall.
Furthermore, the inner case secures a plug board parallel to the
case under the lower separating wall. The electronic part board and
the plug board are connected by metal pins. One end of each of the
metal pins is fixed to the electronic part board and the other is
fixed to the electronic part board. Each of the metal pins pierces
through a hole and is retained in the inner case. The outer casing
has an open end which is closed by a bottom cover. The bottom cover
has a plurality of through holes for plug pins which extend
outwardly from the outer casing.
[0019] The construction of the electric shaver is characterized by
the simplicity of construction and easiness of assembling work
wherein the electronic part board and the plug board are fixed on
the inner case and the inner case is then inserted into the outer
casing. The advantage of the electric shaver according to the
present invention is obtained by the construction wherein the inner
case is formed integral with the lower separating wall abutting on
the internal surface of the outer casing, and the electronic part
board and the plug board are connected by metal pins penetrating
the lower separating wall. With its simple construction, the
electric shaver according to the present invention enables to
secure the electronic part board on the plug pins in a position.
Using the metal pins instead of lead wires connecting the
electronic part board and the plug board, the shaver according to
the present invention enables to eliminate lead wires connecting
the electronic part board and the plug board whereby facilitating
the assembly work.
[0020] The outer casing of the shaver according to the present
invention is preferably fabricated of a plastic with tubular
configuration. The lower separating wall is provided with an O-ring
at its periphery for a watertight connection with the outer casing,
while the plug pins are provided with an O-ring abutting on the
inner surface of the bottom cover for a watertight connection with
the through holes. The construction of the electric shaver of the
present invention can be used for a watertight electric shaver.
[0021] The electric shaver with a watertight lower separating wall
and the bottom cover with a watertight plug pins is preferably
provided with a safety valve on the bottom cover which functions as
a relief valve at a predetermined pressure level in a space
enclosed by the lower separating wall, bottom cover and the outer
casing. The safety valve thus prevent gas from entering the upper
block whereby avoiding damages to electronic parts.
[0022] Furthermore, the inner case made of a plastic has latch
means integral with the case to retain the electronic part board.
Thus the electric shaver of the present invention enables to
retains the electronic part board in the inner case.
[0023] The ends of the metal pins of the electric shaver of the
present invention are fixed by soldering to the electronic part
board or to the plug board. By this method, the metal pins are
secured to the electronic part board and to the plug board.
[0024] The inner case according to the present invention is formed
integral with a tubular case to retain two batteries disposed side
by side and parallel to the electronic part board. The inner case
is preferably formed integral with hub portions for retaining the
bottom cover. The hub portions are disposed at hollow spaces
between the two cylindrical batteries.
[0025] The electric shaver having the construction that the inner
case with an integral tubular case, in which batteries are
retained, is preferably provided with the retainer having a closed
upper end and an open bottom end. The lower ends of the batteries
retained in the tubular retainer are connected to lead plates which
are in turn connected to the plug pins. The electric shaver is
capable of retaining the batteries by means of lead plates and plug
pins.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an exploded oblique view of an embodiment
according to the present invention.
[0027] FIG. 2 is an exploded rear view of the electric shaver shown
in FIG. 1.
[0028] FIG. 3 is a side elevational view of the inner case shown in
FIG. 2.
[0029] FIG. 4 is a circuit diagram showing the electrical circuit
of an embodiment according to the present invention.
[0030] FIG. 5 is a cross-sectional view of the inner case shown in
FIG. 2.
[0031] FIG. 6 is a vertical cross-sectional view of the inner case
shown in FIG. 2.
[0032] FIG. 7 is an exploded oblique view of an outer casing and an
inner case as partly inserted in the outer casing.
[0033] FIG. 8 is an exploded cross-sectional view of lower portion
of the electric shaver shown in FIG. 1.
[0034] FIG. 9 is a cross-sectional view of lower portion of an
electric shaver.
[0035] FIG. 10 is an enlarged oblique view of a bottom cover.
[0036] FIG. 11 is an oblique view of another embodiment of the
electric shaver according to the present invention.
[0037] FIG. 12 is an oblique view of the chamber shown in FIG.
11.
[0038] FIG. 13 is a cross-sectional view of the chamber shown in
FIG. 12.
[0039] FIG. 14 is a vertical cross-sectional view of the chamber
shown in FIG. 12.
[0040] FIG. 15 is a schematic view of a power source connector.
[0041] FIG. 16 is an oblique view of an adapter connected to the
plug shown in FIG. 15.
[0042] FIG. 17 is a front view of the plug shown in FIG. 15.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The electric shaver as shown in an exploded oblique view in
FIG. 1, in a rear view in FIG. 2, and in FIG. 3 comprises a motor 4
which drives an inner blades 6, a battery 3 for energizing the
motor 4 an electronic part board 5 connected to the battery 3, an
inner case 2 to which the part board 5, the battery and the motor 4
are secured, and a plug board 33 having a pair of plug pins 32 the
extremities of which project beyond the outer casing 1. FIG. 3
shows an inner case 2 partly drawn out of the outer casing.
[0044] The motor 4 drives the inner blades in a reciprocating
motion by means of a transforming mechanism which transforms the
rotational motion into a reciprocating motion. The transforming
mechanism may be of the type presently in use or in the future. For
example, a mechanism comprising a cam shaft 12 secured to a motor
spindle 11, and a reciprocating member 14 to which the cam shaft 12
as well as the inner blades 6 is secured. The inner blades 6
reciprocate in slidable engagement with the inner surface of the
outer blade 7 to cut off hairs projecting through beard cutting
ports of the outer blade 7.
[0045] The battery 3 may be a Ni-MHD,Ni-CD, or Ni-Lithium type. One
or several batteries are retained in the inner case 2. FIG. 2 shows
a pair of batteries 3 retained in a retainer 8 of the inner case
3.
[0046] FIG. 4 shows a circuit diagram which includes electronic
parts mounted on the part board 5. The circuit on the part board 5
includes a charge-control circuit for the battery 3 and a motor
4-controlling circuit. The battery-charging circuit includes a
switching device connected to the battery 3 and the charging
terminals 15, a microprocessor 16 for controlling ON/OFF states of
the device Q1, and a charging resistor R connected in series
between the switching device Q1 and the battery 3. The part board
may include a power supply circuit capable of transforming the 100
V commercial power to a charge voltage of the battery.
[0047] The charge-control circuit supply a charging current to the
battery 3 through the switching device Q1 and the charging resistor
R. The switching device Q1 generates heat by the energy
proportional to the multiplication of current and voltage drop. The
charging resistor R generates heat due to the energy proportional
to the multiplication of the square of current and resistance. The
switching device Q1 and the charging resistor R are heat-generating
parts 10 because these parts conduct large currents. The power
supply circuit also generates heat because the circuit includes a
transformer for lowering 100 V commercial voltage into a charging
voltage, a switching device and a rectifying diode which conduct a
large current.
[0048] The charge-control circuit shown in the figures for the
battery 3 is capable of calculating by means of a microprocessor
the residual power of the battery based on the discharge time. The
residual power is displayed by means of LEDs (not shown). The
microprocessor 16 calculates ON time of switching device Q1 based
on the residual power and controls the switching device. The
battery 3 is charged when the switching device is turned on as the
electric shaver is placed on the charger or the power cable is
connected to a commercial power outlet. The microprocessor
calculates the time needed to fully charge the battery 3 and turns
off the switching device Q1 when the battery3 is fully charged,
thus terminating the charging operation.
[0049] The motor-controlling circuit includes a switching device Q2
such as FET, a switching circuit 18 for turning on and off the
switching device Q2, and a push switch 19 for inputting switching
signals into the switching circuit18. The switching circuit 18
switches on and off the switching device Q2 as the push switch 19
is pushed to send "H" or "L" signals. The circuit is characterized
in that a push switch of simple structure is capable of turning on
and off the motor. As the circuit supplies large currents to the
motor, the switching device Q2 in the circuit generates greater
amount of heat. Therefore, the switching device Q2 is preferably
placed in a section of the inner case. Instead of placing the
switching device Q2 in a section, the device may be mounted on the
rear side of the part board because the switching device Q2
conducts smaller currents compared with the switching device Q1
generating less heat.
[0050] The device board 5 shown in FIG. 3 has electronic parts on
both sides. Heat generating device 10 is mounted protruding into
the section 9 on the front side of the electronic part board 5. The
electronic part board 5 has electronic parts 20 on the rear side at
the position corresponding to the battery 3 and the motor 4. The
electronic part board 5 is secured close to the battery 3 and the
motor 4 in the inner case 2.
[0051] The inner case 2 is formed of plastics as an integral part.
The inner case 2 shown in FIG. 3 is provided with a mounting
surface at the rear for the part board 5. Holding latches are
provided integral with the inner case, at both sides of the
mounting surface, resiliently holding the board 5 at both sides.
Each of the holding latches has a hook-like end as shown in FIG. 5,
which holds the part board at its sides. The inner case 2 shown in
the figure is provided with a pair of holding latches 21 at each
side, totaling four holding latches, securing the electronic part
board 5 at two location on each side.
[0052] As shown in FIG. 2, the inner case 2 is further provided
with a section 9 between the motor 4 and the battery 3. The section
9 is provided to admit heat-generating part 10 mounted on the part
board. The room 9 has a separating wall separating the room 9 from
the battery 3. The inner case 2 has another wall 23 which is lower
than the wall 22 separating the room from the motor 4. As shown in
FIG. 2, the wall 23 has a groove 24 on the side facing the motor 4
which receives a bearing housing 4A projecting from the casing. The
groove 24 receives the motor housing projection 4A whereby securing
the motor 4.
[0053] The wall 22 facing the battery 3 serves as a cover to close
the bottom opening of the tubular retainer 8.
[0054] The inner case 2 shown in FIG. 2, FIG. 3 and FIG. 6 is
provided with a tubular retainer 8 as an integral part for
receiving the battery 3. The tubular retainer ends in a wall 23 at
its bottom which separates the room 9 from the battery and prevents
the battery 3 from slipping into the room 9. The opposite end of
the retainer 8 is open for loading the battery 3. The inner case
shown in the figures has a tubular retainer 8 capable of retaining
a pair of juxtaposed cylindrical batteries.
[0055] Furthermore, the inner case 2 has side walls 25 integral
with the inner case, which hold the motor 4 on both sides. The side
walls 25 join with the tubular retainer 8 for the battery 3 at
their lower end.
[0056] Thus, the inner case 2 shown in the figures is provided with
the square room 9 enclosed by the side walls 25, separating wall 22
facing the motor 4. The room 9 receives the heat-generating parts
10 mounted on the electronic part board. The room 9 is open 29
toward the electronic parts board so as to admit the
heat-generating parts 10 into the room.
[0057] Furthermore, the heat-generating part 10 in the FIG. 5
admitted in the right-side room is covered with a heat-resistant
tube 31. The heat-resistant tube 31 prevent the heat-generating
part 10 from contacting the inner case 2, whereby protecting the
batteries from heat.
[0058] As shown in FIG. 5 and FIG. 6 (lateral cross-section), the
inner case is open at both upper and lower end of the room 9.
Furthermore, each of the side walls 25 has an opening at the bottom
as shown in FIG. 5 and 6 so as to let the air out. The height of
the side walls is lower than the battery case 8 so that air can
pass through the gap between them.
[0059] The rooms 9 which are open at top and bottom allow leading
wires connecting the electronic part board 5 and the motor 4 to go
through the open end. In the electric shaver shown in the figures,
the leading wires 30 are connected e.g., by soldering at their one
end to the upper surface of the part board 5. The leading wires 30
go upward through the room to terminals of the motor 4. The
structure of the room allows an optimum wiring of the leading wires
30 because leading wires no more require a clearance between the
inner case and outer casing for the wires to pass through.
[0060] The inner case 2 shown in FIG. 3, FIG. 7 and FIG. 8 has a
lower separating wall 26 as its integral part which closes the
bottom end of the outer casing 1, and to which is connected, at its
upper surface, the electronic part board 5, and at its lower
surface a plug board 3 parallel with the separation wall. The lower
separating wall 26 has a groove 26A at its periphery for receiving
an O-ring 34. The O-ring 34 in the groove 26A establishes a
watertight contact with the inner surface of the outer casing, as
the inner case 2 is retained in the outer casing to give the outer
casing watertight structure.
[0061] The lower separating wall has through holes 26B through
which a metal pin 35 is inserted connecting the electronic part
board 5 and the plug board 23. The lower separating wall 28 of the
inner case shown in FIG. 7 and FIG. 8 is provided with three though
holes 26B. Each of the through holes 26B is a circular hole having
the diameter equal to that of the metal pin. Thus, the holes 26B
are able to keep the metal pin in a fixed position.
[0062] The lower separating wall 26 shown in FIG. 8 has an enlarged
recess at the lower surface, in which an O-ring is received so that
the pin 35 is secured watertight to the tower separating wall 26.
The through holes in the lower separating wall 26 receive a flanged
portion 35A of the metal pin 35. Each of the through holes 26B
admits the metal pin 35 inserted from the plug board 33 until the
pin reaches the electronic part board 5 whereby holding the metal
pin 35 and the electronic part board in position. The O-ring-flange
structure gives the through holes 26B water tightness.
[0063] The lower separating wall 26 shown in FIG. 7 and FIG. 8 has,
as integral parts thereof, support members 37 for supporting the
plug board, projecting toward the bottom of the case, and support
members 38 for supporting the bottom cover 39. The plug board
support members 37 and bottom cover support members 38 support the
plug board 33 at four points. With these support members, the inner
case is capable of supporting the lower separating wall 26 and the
plug board 33 parallel to each other. The support members 37, 37
support the plug board 33 on the bottom sides, whereas the support
members 38,38 support the board on both sides as shown in FIG. 9.
Each of the support members 37, 37 has a L-shaped recess for
receiving the plug board 33. As shown in FIG. 8 and FIG. 8, the
support members 38, 38 have an enlarged portion 3A at their root to
form a shoulder to support the plug board 33.
[0064] The support member 38 has a threaded hole which provides an
anchor for a screw 40 which secures the bottom cover 39. The inner
case 2 shown in FIG. 7 has bottom cover supports 38, 38 aligned
with the gorge between two juxtaposed batteries. The support
arrangement enables to make the inner case 2 and lower separating
wall 26 smaller because the space between the batteries is used to
put the support members 38, 38.
[0065] The metal pin 35 inserted into the through hole 26B is
fastened at one end to electronic part board 5 and at the other end
to the plug board 33, whereby holding these boards in place. The
metal pin 35 is fastened, e.g., by means of soldering to the
electronic part board and plug board33. As the other way, the metal
pin 35 can be detachably fastened to the electronic part board and
plug board33. The inner case 2 shown in figures has three metal
pins connecting the electronic part board 5 and plug board 33. Each
of the two metal pins 35, 35 is connected to either of the plug
pins 32, 32. Either of the two plug pins 32, 32 is connected to
either of the electrodes of the battery 3 by means of a leading
plate 41. The other plug pin 32 is also connected to the electrode
of the battery by means of a leading plate 41.
[0066] The electronic part board 5 and the plug board 33 are made
of a printed circuit board of epoxide resin with a thin conductive
metal layer on its surface. The part board 5 and plug board 33 have
an enlarged metal layer to which the metal pin is connected. The
plug board 33 has a recess 33A intended to insert the metal pin 35
in order to firmly secure the board in the inner case 2. The recess
33A may be a through hole or a groove capable of holding the metal
pin 35. The plug board 33 is provided with a thin layer of metal
connecting a pair of plug pins 32 and a pair of metal pins 35.
[0067] The outer casing 1, which is made of plastics, as shown in
FIG. 1 and FIG. 2, exposes an oscillating rod 13 secured on a
reciprocating member 14 through a watertight sealing member at its
upper end while the bottom end is closed by means of a bottom cover
39 with watertight sealing means. In order to ensure a watertight
contact of the reciprocating mechanism, the upper opening 1A of the
outer casing 1 has a rubber membrane 42 through which extends the
oscillating rod 13. The rubber membrane 42 is fixed watertight at
its periphery to the opening 1A of the outer casing 1 which
penetrates the oscillating rod 13. The through hole of the rubber
membrane 42 is secured watertight to the oscillating rod 13.
[0068] As shown in FIG. 8 and FIG. 9, the bottom cover 39 has a
pair of through holes 39A, 39A for the plug pins 32. The plug pins
penetrate the through holes 39A,39A with watertightness so that the
ends of the plug pins protrude out of the outer casing 1. In order
for the plug pins 32 to penetrate with water tightness, the pins 32
are provided with an O-ring 43 which is tightly pressed on the
inner surface of the bottom cover 39. Furthermore, the bottom cover
39 is provided with another O-ring 44 at its periphery to ensure
watertight coupling.
[0069] The bottom cover 39 has a chamber 45 aligned with the plug
pins 32 to admit the pins 32. The chamber 45 is deep enough to
prevent the pins from protruding out of the contour of the outer
casing. The chamber is so configured as to receive a power source
plug. The plug pins 32 are connected by means of the power source
plug to the power outlet.
[0070] The bottom cover 39 is provided with a safety valve to
discharge the gas emitted by the battery 3 when the internal
pressure becomes critical. The safety valve 46 consists of a
membrane fixed in the inner surface of a relief hole 39B which
penetrates the bottom cover 39. The membrane sealing the relief
hole 39B breaks and let out air when the internal pressure rises
high enough. As shown in FIG. 10 schematically, the relief hole 39B
is made inside the chamber 45 and communicates with a groove 47 on
the wall of the chamber 45. The relief hole 39B is protected from
damage by piercing with e.g., a needle by the user. The other
material of the sheet of a membrane is one through which the air
can communicate and water cannot communicate.
[0071] The above-mentioned electric shaver has an air-tight chamber
between the lower separating wall 26 and bottom cover 39, both of
which are sealed by resilient O-ring 34 and 44 at their periphery.
The battery case which retains the battery 3 is sealed at the upper
end whereas communicates with the air tight chamber at the bottom
end. The structure of the battery case enables air-tight retention.
Once gas is emitted from the battery 3, the chamber pressure rises.
When the pressure rises over the preselected level, the membrane is
broken by the pressure to let air out. In the electric shaver with
the structure above, the gas emitted from the battery 3 is not
allowed to go into the chamber for the electronic parts including
the motor 4, whereby protecting electronic part board from the gas.
Even if the membrane is broken and water comes into the chamber,
the electronic part board or the motor 4 is protected from
water.
[0072] Furthermore, the inner case 22 is provided with a cross rib
27 at the top of the side walls 25 for retaining the motor 4. The
motor 4 is retained by the cross rib 27, side walls 25 and
separating wall 23. Furthermore, the inner case 22 has a connecting
mechanism 28 at the top of the side walls 25 for securing resilient
arms of reciprocating member 14.
[0073] FIG. 11 shows another embodiment having a bottom cover with
a chamber of another configuration for receiving power source plug.
FIG. 12 shows schematic view of the chamber 145 on an enlarged
scale, FIG. 13 and FIG. 14 show a cross-sectional and vertical
cross-sectional view respectively. The chamber 145 shown in these
figures has a horizontally elongated square configuration. The
chamber 145 has an axially elongated configuration as shown in FIG.
15 and FIG. 16 so that it enables smooth and guided insertion of
the power source plug. The power source plug 53 is inserted
perpendicularly to the surface of the bottom cover 139. Therefore,
the chamber 145 has an axially elongated column-like configuration.
"column-like" means an chamber having the same cross-section along
the direction of insertion.
[0074] The chamber 145 shown in FIG. 12 through 14 has an elongated
guide projection 148 to prevent a wrong insertion of the plug 53.
The guide projection 148 formed integral with the bottom cover
extends in the direction of insertion of the plug 53. The guide
projection 148 has a triangular cross-section and is formed at the
middle of the side walls. Furthermore, the chamber 145 shown in the
figures has rounded corners at both sides, the corner of each side
having different diameter so that wrong insertion of the plug is
avoided. The chamber 145 shown in the figures has a kind of rounded
corners with a smaller diameter on the side where the guide
projection is formed as well as another kind of rounded corners
with different diameter on the other side. 46 Furthermore, the
chamber 145 shown in the figures is provided with a groove 147
opposite to the guide projection 148, which communicate with a
through hole 139B in the bottom cover 139. The through hole 139B is
closed with a membrane 149 at the inner face of the outer casing
101. The membrane 149 seals the through hole 139B in normal use,
but it breaks under pressure to discharge the air inside the outer
casing when the pressure inside the outer casing 101 rises to a
certain level. The through hole 139B communicating with the groove
inside the chamber together with sealing membrane 149 function as a
safety valve 146. The safety valve is protected from piercing with
e.g. a needle by the user.
[0075] The chamber 145 is provided with a leak prevention wall 150
at the bottom to prevent leakage of current due to conductive water
and corrosion of the plug pins by current due to conductive water.
The chamber 145 shown in the figures is divided into two blocks by
leak prevention wall 150. The leak prevention wall is formed at the
bottom of the chamber as a projection integral with the bottom
cover made of plastics. The leak prevention wall 150 prevents
currents from flowing between the plug pins 132,132. The leak
prevention wall is made of insulating materials. The outer casing
of electric home appliances is made of plastics without exception.
Therefore, the leak prevention wall 150 is made integral with the
outer casing of plastics.
[0076] The leak prevention wall is not capable of preventing
leakage if it is too low. Therefore, the height of the wall is
preferably 1-5 mm or more preferably 2-4 mm. The leak prevention
wall 150 is formed as a continuing part of the guide projection
148. The leak prevention wall 150 functions as a guiding member for
the power source plug 53 when the plug is inserted into the chamber
145. The leak prevention wall 150 avoids improper insertion of the
plug into the chamber 145 by virtue of the recess 54 of the plug 53
shown in FIG. 17. To avoid faulty insertion of the plug 53, the
leak prevention wall 150 must be strong enough. Therefore it is
0.5-2 mm in thickness or more preferably 1 mm in thickness.
[0077] The chamber shown in FIG. 13 is provided with a leak
prevention wall 150 which is joined at one end to the inner face of
the chamber 145, but is separated at the other end from the chamber
wall leaving a narrow gap 151 for the through hole 139B of the
safety valve.
[0078] A pair of plug pins 132, 132 are fixed, one on each side of
the leak prevention wall, spaced apart and parallel to each other.
In the figure, Two plug pins are fixed in the chamber spaced apart
along the longer side of the chamber. To supply power, at least two
plug pins are needed. If needed, three or more plug pins may be
used, in which case two of them are used for supplying power, one
for sending signals.
[0079] In order to realize water-proof structure of the outer
casing 101 of the shaver shown in the figures, the plug pins
132,132 are sealed and fixed to the bottom cover 139. As shown in
FIG. 14, the plug pins have a flange 152 which presses an O-ring
143 to the inner surface of the bottom cover whereby realizing
water-proof plug pins. The plug pin 132 is fixed to the plug board
133 secured in the outer casing 101. The flanged plug pin 132
exerts pressure on the O-ring 143 to obtain water-proof bottom
cover139.
[0080] As shown in FIG. 15, the power source plug 53 has an insert
portion 53A at its end which is to be inserted in a right position
or pulled out of the chamber 145. The insert portion 53A of the
plug is configured corresponding to the inner configuration of the
chamber 145, whereby ensuring smooth and sufficient insertion.
[0081] The power source plug 53 is connected by way of the power
cord 55 to the adaptor 56.
[0082] Next to the insert portion 53A, the power source plug 53
shown in the figures has a gripping part 53B, and a resilient
bushing part 53C integral therewith of plastics. The gripping part
53B is sized large so that the user can grip easily. The bushing
part 53C is flexible to prevent the cord from severing from
wear.
[0083] As shown in FIG. 17, the power source plug 53 has an recess
54 at the end of the insert portion 53B to admit the leak
prevention wall 150 in the chamber 145. The depth of the recess 54
is equal or little greater than the height of the leak prevention
wall 150. The width of the recess 54 is equal to that of the wall
150. As the power source plug 53 is inserted into the chamber 145,
the recess 54 in the insert portion 53A receives the leak
prevention wall 150.
[0084] The insert portion 53A is provided with connecting terminals
(not shown) to be connected to the plug 132, 132. The connecting
terminals are made with metal plate which is formed in a resilient
cylinder. The internal diameter of the cylinder is slightly less
than the external diameter of the plug pin 132. When the plug pins
132,132 are inserted into the cylindrical connecting terminals, the
resilient cylinders expand slightly and exert pressure on the plug
pins 132,132 to establish a firm connection. The insert portion 53A
is provided with a pair of guide holes to receive the plug pins
132.
[0085] Furthermore, each of the connecting terminals is connected
to a lead wire within the gripping part 53B, which lead wire is
connected to the adaptor 56. When the power source plug 53 is
inserted in the chamber145, the adaptor 56 is connected via lead
wire and connecting terminals to the plug pin 132 to supply power
to the electric apparatus.
[0086] The electric shaver of the type described above has the
advantages that current leakage flowing through the water trapped
in the chamber as well as faulty connection of the plug and plug
pin is avoided. The advantage is attained by implementing leak
prevention wall in the chamber separates the water trapped around
the plug pins and makes a longer leakage channel whereby avoiding
current leakage. The leak prevention wall reduces current leakage
even if water is trapped in the chamber thus reducing
electro-erosion of plug pins or connector terminals. The advantage
is especially important for a washable electric household appliance
e.g., an electric shaver, because electro-erosion shortens service
time of electric appliances even if the sealing of the casing is
perfect.
[0087] Furthermore, the electric shaver with the leak prevention
wall has the advantage that the wall functions as a guide member
when the power source plug is inserted ensuring a smooth and
sufficient insertion of the power source terminals into the plug
pins.
[0088] Furthermore, the electric shaver described above is capable
of preventing inclined insertion of the power source plug into the
chamber by virtue of the guiding recess of the plug. In other
words, the power source plug is perfectly inserted into the chamber
avoiding faulty connection between the plug pins and the connector
terminals. Undesirable forces can be eliminated when the plug is
pulled out of the chamber.
[0089] As this invention may be embodied in several forms without
departing from the spirit of essential characteristics thereof, the
present embodiment is therefore illustrative and not restrictive,
since the scope of the invention is defined by the appended claims
rather than by the description preceding them, and all changes that
fall within meets and bounds of the claims, or equivalence of such
meets and bounds thereof are therefore intended to be embraced by
the claims.
* * * * *