Note: Descriptions are shown in the official language in which they were submitted.
CA 02360122 2001-10-25
WATERPROOF KEYBOARD ASSEMBLY
BACKGROUND OF THE INVENTION
( 1 ) Field of the Invention
The invention relates to a keyboard assembly, and more particularly to
an improvement which can meet a waterproofing requirement under
accidental damping situations.
(2) Description of the Prior Art
It is well known in the art that keyboards have various application in
telephone sets, calculators, control panels, tele-communicating devices,
computers, and so on. Especially in an automatic office or an auto-
manufacturing field, the keyboard utilization seems to be inevitable.
However, in order to reduce the cost, keyboards in the ant are not
specifically designed to be waterproofing. Thus, in case of water merging,
circuit short-cut of the keyboard becomes an unavoidable problem.
Referring now to Fig. l, a keyboard assembly in the aut is shown
explodedly. The keyboard assembly 1 comprises a first circuit board 11, a
first rubber pad 12, a first mold frame 13, and a plurality of first keytops
14.
In the first mold frame 13, there exists a plurality of penetrating first
button
entry 132 arranged in a square array. Circumscribing each of the first
button entry 132 is a f rst entry brim 133 to be a counter part to a first
keytop rim 141 of the first lceytop 14. The first entry brim 133 is the stop
for the first keytop 14 to be positioned in the corresponding button entry
132. Also, the keyboard assembly 1 in the art also comprises a plurality of
first mounting posts 131 on the sur face facing the first r ubber pad 12.
The fir st rubber pad 12 is a soft sheet with a plurality of first
conductive pills 121 arrayed on the surface facing the first circuit board 11
at each corresponding location to each first keytop 14.
CA 02360122 2001-10-25
The first circuit board 11 is the counter part to the first rubber pad 12,
with cir cuit on the surface facing the fir st rubber pad 12. The first cir
cuit
board 11 also comprises a plug ality of fir st I110UI7t11'lg holes 111 as
counter
parts to the first mounting posts 131 extruding from the first mold frame 13.
Along one side edge of the first circuit board 1 I is the first output pins
112
of the keyboard assembly 1.
While assembling aforesaid keyboard assembly 1, the first circuit
board 11 is pressed to f1r1111y engage the first rlold frame 13 by the first
mounting holes I I 1 and the first mounting posts 131, and to encompass
the first keytops I4 and the first rubber pad 12 i1-1 between.
In application, one of the first keytops I4 is depressed to press down
the corresponding first conductive pill 121 of the first rubber pad 12, and
thus the corresponding first conductive pill I?1 touches the surface of the
first circuit board I 1 so that a specific signal is~sending out of the
keyboard
assembly I via the fir st output pins 112.
Apparently, the keyboard assembly 1 in the art described above is not
a waterproof device. In case that water emerges over the first mold frame
13, the water will enter the space between the first rubber pad 12 and the
first circuit board I 1 through the splits between the first keytops 14 and
the
first mold frame I3, as well as the abysses in and around the first rubber
pad 12. Thus, short-cutting will be inevitable and dysfunction this
keyboard assembly 1 in the art.
However, in generally speaking, keyboards with waterproofing
application, such as those used to anti sever a environment, pressure resist,
or underwater application, are equivalent to high pricing. Regarding the
financing, it is unconvincing to use such high-pr icing keyboar ds in
ordinary application just for the reason of avoiding accidental short-cutting.
Moreover, the cost in upgrading all keyboards to be waterproofing is
substantial, and sometimes can't be afforded icy limited budget in some
business.
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CA 02360122 2001-10-25
SUMMARY OF TIRE INVENTION
Accordingly, it is a primary object of the present invention to provide
a waterproof keyboard assembly which is capable of proceeding normal
operation under an accidental water ing environment.
The present invention comprises a mold frame, a plurality of keytops
mounting in the mold frame, a soft and seamless rubber pad to seal from
sides of the mold frame, and a circuit board separated ti~om the mold frame
by the rubber pad. To assemble the present invention, the circuit board is
pressed firmly onto the 11101d fra111e vla 1110L1ia1 ng means locating on the
edges of facing surfaces of the mold frame and the circuit board, and to
hold the rubber pad and keytops firmly in between. The mounting means
can be screwing or pin-hole combination by ultra-sonic welding or any
other thermal welding method available.
Waterproofing provided by the present invention is achieved by
firmly squeezing the seamless rubber pad to extend all its edges, and thus
forming a sealing effect to separate possible emerging water, which
entering from the mold frame, from the space forming between the circuit
board and the rubber pad. Therefore, the possibility of short-cutting can be
reduced to a substantial extend. Preferably, waterproofing can be
synthesized by providing a surrounding interior circum-slot to the mold
frame and a corresponding extruding pad rim to the rubber pad.
Moreover, the keytops and the rubber pad according to the present
invention can be manufactured as a unique compact part with a plurality of
keytops bulging from the rubber pad surface to meet various application.
It is another object of the present invention to provide a simple-
structured keyboard assembly for waterproofing, which is competitive in
its low manufacturing cost.
It is a further object of the present invention to provide a waterproof
keyboard assembly for upgrading a keyboard device in the art without
changing any other components of the device.
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All these objects are achieved by the waterproof keyboard assembly
described below.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be specified with reference to its
preferred embodiment illustrated in the drawings, in which
FIG.l is an exploded view of a keyboard assembly in the art.
FIG.2 is an exploded view of the preferred embodiment of the
waterproof keyboard assembly in accor dance with the present invention.
FIG.3 is a perspective view of the third rubber pad of another
preferred embodiment of the waterproof keyboard assembly in accordance
with the present invention.
DESCRIPTION OF THE PREFERRED >CMBODIMENT
is
The invention disclosed herein is directed to a waterproof keyboard
assembly. In the following description, 11t1n1erOLlS details are set forth in
order to provide a thorough understanding of the present invention. It will
be appreciated by one skilled in the art that variations of these specific
details are possible while still achieving the results of the present
invention.
In other instance, well-known components are not described in detail in
order not to unnecessarily obscure the present invention.
Referring now to Fig. 2, a waterproof keyboard assembly in
accordance with the present invention is illustrated explodedly. The
waterproof keyboard assembly 2 can meet the waterproofing requirement
in case of accidental water emerging, and comprises a second circuit board
21, a second rubber pad 22, a second mold ti~ame 23, and a plurality of
second keytops 24.
The second mold frame 23 is the installation platform for
accommodating the block-shaped second keytops 24, the second rubber
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pad 22, and the second circuit board 21, and further has a plurality of
penetrating second button entries 233 arranged in shape of a square array.
Circumscribing each of the second button entry 233 is a second entry brim
234 to be a counter part of a second lceytop rim ?41 of the second :lceytop
24. The second entry brim 234 provides a stop for the second keytop 24 to
be positioned in tile COrTeSpOIldlllg second button entry 233. Also, the
second mold frame 23 further comprises a plurality of mounting points
surrounding edges of the second mold frame 23 surface facing the second
rubber pad 22.
I0 The second rubber pad 22 is a soft, seamless, and flexible sheet pad to
be installed onto the second mold frame 23 surface, further comprising a
plurality of second conductive pills 221 attached to the opposite surface
thereof to the second mold flame 23 surface where the second mounting
points locate, at each corresponding position of each second keytop 24.
IS Preferably, the second conductive pills 221 are carbon pads.
The second circuit board 21 is mounted adaacent to the second rubber
pad 22 surface, where the second conductive pills 221 locate, for
generating a signal while one of the second conductive pills 221 is pressed
to contact the second circuit board 21 surface through depressing the
20 corresponding second l:eytop 24. The second circuit board 21 further
comprises a plurality of COUlltel II10ui1tlllg points surrounding edges
thereof to go with tile 1110L1nt111g p0111tS Ot the second mold frame 23.
Along one side edge of the second circuit board 21 is the second output
pins 212 of the waterproof Keyboard assembly 2.
25 Preferably, the mounting points of the second mold frame 23 are a
plurality of second 1110Llntitlg pOStS 231 extruding from the surrounding
edges of the second mold frame 23 surface, and the counter mounting
points of the second circuit board 21 are a plurality of corresponding
second mounting holes .' 1 I surrounding edges of the second circuit board
30 21.
Altel-natively, the mounting points and the counter mounting points are
a plurality of mounting holes surrounding edges oi~ the second mold frame
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23 and corresponding t110LlI1tIllg pOStS SL111'OL111Cllng edges of the second
circuit board 21, respectively.
Also preferably, mounting points and the counter mounting points are
a plurality of 1110L111tlng screws and corresponding mounting holes,
respectively.
By f11111 C0121b1I1atlon Of the 1110untlng pOln tS Ol' the second mold frame
23 and the counter mounting points of the second circuit board 21, the
second circuit board 21 compresses the second rubber pad 22 (who has an
original thiclcness enough to be squeezed and expended to a further thinner
and wider sheet) onto the second mold frame 23 and thus renders a seal
function by squeezing the seamless second rubber pad 22 in between to
prevent the water outside the second mold frame 23 from entering the
second circuit board 21. Also, such firm combination can be achieved by
ultra-sonic welding or any other thermal welding method available.
In application, one of the second lceytops 24 is depressed to press
down the corresponding second conductive pill 221 of the second rubber
pad 22, and thus the corresponding second condLrctive pill 22I touches the
surface of the second circuit board 21; so that a specific signal is sending
out of the waterproof keyboard assembly 2 via the second output pins 212.
Preferably, as shown in Fig. 2, waterproofing of the preferred
embodiment can be synthesized by providing a surrounding interior
circum-slot 232 to the second mold frame 23 and a corresponding
extruding pad r im 222 to t1 a second r ubber pad 22 .
Referring now to Fig. 3, a third rubber pad 22b of another preferred
embodiment of the waterproof keyboard assembly in accordance with the
present invention is illustrated perspective. The third rubber pad 22b is
manufactured by putting the second rubber pad 22 and the second keytops
24 of the aforesaid e111bOdIlllent, the waterproof Iceyboard assembly 2
shown in Fig. 2, together as a unique compact part. In the preferred
embodiment, the mold Frame, the circuit board, and corresponding
positions of the keytops and conductive pills are all similar to those
describing in aforesaid embodiment.
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CA 02360122 2001-10-25
While the present invention has been particularly shown and
described with reference to three preferred embodiments, it will be
understood by those skilled in the art that various changes in form and
detail may be without departing from the spirit and scope of the present
invention.
