|
| United States Patent
|
6,073,341 |
| Odorfer |
June 13, 2000 |
Dome switch assembly system
Abstract
A machine method for providing a dome switch sub-assembly used
for providing a keyboard-type user input to electronic devices. A
spacer layer, attached to a retaining layer, having a plurality of
spacer layer openings for receiving a plurality of dome switches is
placed upon a moveable machine table. The dome switches, arranged in
reel form, are machine removed and placed into the spacer layer
openings. A removable release liner is then attached to the spacer
layer. Also a complete dome switch assembly is provided. A spacer
layer, attached to a circuit board, having a plurality of dome
switch openings is placed on a moveable machine table. The dome
switches, arranged in reel form, are machine removed and placed into
the spacer layer openings. A retaining cover is attached to the
spacer layer. An overlay layer, attached to the retaining cover
layer, may also be provided.
| Inventors: |
Odorfer; Richard A.
(Prescott, AZ) |
| Appl. No.:
|
09/038,268 |
| Filed: |
March 10, 1998 |
| Current U.S.
Class: |
29/623 ;
200/5A; 200/5B; 29/622 |
| Current
International Class: |
H01H
13/70 (20060101); H01H 069/02 () |
| Field of
Search: |
29/622,623,430,453,773,797,740 200/1,5A,275,159,302 |
References Cited
[Referenced By]
U.S. Patent
Documents
|
|
|
|
3988551 |
October 1976 |
Larson |
|
4005293 |
January 1977 |
Boulanger |
|
4085306 |
April 1978 |
Dunlap |
|
4194097 |
March 1980 |
Bradam |
|
4263485> |
April 1981 |
Corwin |
|
4341498 |
July 1982 |
Ellis |
|
4365120 |
December 1982 |
Pounds |
|
4463234 |
July 1984 |
Bennewitz |
|
4499343 |
February 1985 |
Prioux |
|
4811175 |
March 1989 |
Desmet |
|
5500997 |
March 1996 |
Kobayashi et al. |
|
Primary Examiner: Young; Lee
Assistant Examiner: Smith; Sean P.
Attorney, Agent or Firm:
Stoneman; Martin L.
Claims
What is claimed is:
1. A machine method for providing, for dome switches of the type
wherein each dome switch comprises an approximately hemispherical
top surface having an apex, a dome switch sub-assembly having a
retaining cover layer, a spacer layer having a plurality of openings
for respectively receiving a plurality of dome switches, and a
release liner, comprising the steps of:
a. positioning on a machine table having a machine-movable surface
an initial assembly comprising
i. said retaining cover layer, having a retaining cover top surface,
and
ii. adjacent said retaining cover top surface, said spacer layer,
having a spacer layer top surface;
b. situating said dome switches, affixed in a dome switch input
reel, over said machine-movable surface of said machine table;
c. machine-blanking respective said dome switches from said dome
switch input reel so that said dome switches drop into respective
said openings of said spacer layer; and
d. placing said release liner on said spacer layer top surface;
e. wherein said machine-movable surface is structured and arranged
for lateral movement in orthogonal directions.
2. A machine method according to claim 1 wherein said retaining
cover layer of said initial assembly is adhesively attached to said
spacer layer.
3. A machine method according to claim 1 wherein said placing of
said release liner on said spacer layer comprises adhesively bonding
said release liner to said spacer layer.
4. A machine method according to claim 1 wherein each substep of
said machine-blanking step comprises:
a. moving said machine-movable table in such manner that said
machine-movable table locates for machine dome switch placement an
unfilled said opening not having therein a said dome switch; and
b. machine-blanking a said dome switch in such manner as to allow
said dome switch to drop into said unfilled opening.
5. A machine method according to claim 1 wherein said dome switch
input reel is structured and arranged in such manner that when said
dome switches are blanked, said dome switches drop into said spacer
layer openings with said apex of said dome switch facing down.
6. A machine method according to claim 1 wherein said positioning
step and said placing step are both manually accomplished.
7. A machine method according to claim 1 wherein:
a. each substep of said machine-blanking step comprises
i. moving said machine-movable table in such manner that said
machine-movable table locates for machine dome switch placement an
unfilled said opening not having therein a said dome switch; and
ii. machine-blanking a said dome switch in such manner as to allow
said dome switch to drop into said unfilled opening; and
b. said dome switch input reel is structured and arranged in such
manner that when said dome switches are blanked, said dome switches
drop into said spacer layer openings with said apex of said dome
switch facing down.
8. A machine method according to claim 7 wherein:
a. said retaining cover layer of said initial assembly is adhesively
attached to said spacer layer; and
b. said placing of said release liner on said spacer layer comprises
adhesively bonding said release liner to said spacer layer.
9. A machine method for providing, for dome switches of the type
wherein each dome switch comprises an approximately hemispherical
top surface having an apex, a dome switch assembly having a circuit
layer, a retaining cover layer, a spacer layer having a plurality of
openings for respectively receiving a plurality of dome switches,
and a release liner, comprising the steps of:
a. positioning on a machine table having a machine-movable surface
an initial assembly comprising
i. said circuit layer, circuit side upwards, and
ii. adjacent said circuit side of said circuit layer, said spacer
layer, having a spacer layer top surface;
b. situating said dome switches, affixed in a dome switch input
reel, over said machine-movable surface of said machine table;
c. machine-blanking respective said dome switches from said dome
switch input reel so that said dome switches drop into respective
said openings of said spacer layer; and
d. placing said retaining cover layer, having a retaining cover top
surface, on said spacer layer top surface;
e. wherein said machine-movable surface is structured and arranged
for lateral movement in orthogonal directions.
10. A machine method according to claim 9, further comprising a last
step of placing an overlay layer, having an icon side, with said
icon side upwards, on said retaining cover top surface.
11. A machine method according to claim 9 wherein said retaining
cover layer of said initial assembly is adhesively attached to said
spacer layer.
12. A machine method according to claim 9 wherein said placing of
said spacer layer on said circuit layer adhesively bonds said
circuit layer to said spacer layer.
13. A machine method according to claim 9 wherein each substep of
said machine-blanking step comprises:
a. moving said machine-movable table in such manner that said
machine-movable table locates for machine dome switch placement an
unfilled said opening not having therein a said dome switch; and
b. machine-blanking a said dome switch in such manner as to allow
said dome switch to drop into said unfilled opening.
14. A machine method according to claim 9 wherein said dome switch
input reel is structured and arranged in such manner that when said
dome switches are blanked, said dome switches drop into said spacer
layer openings with said apex of said done switch facing up.
15. A machine method according to claim 9 wherein:
a. each substep of said machine-blanking step comprises
i. moving said machine-movable table in such manner that said
machine-movable table locates for machine dome switch placement an
unfilled said opening not having therein a said dome switch; and
ii. machine-blanking a said dome switch in such manner as to allow
said dome switch to drop into said unfilled opening; and
b. said dome switch input reel is structured and arranged in such
manner that when said dome switches are blanked, said dome switches
drop into said spacer layer openings with said apex of said dome
switch facing up.
16. A machine method according to claim 15 wherein:
a. said retaining cover layer of said initial assembly is adhesively
attached to said spacer layer; and
b. said placing of said spacer layer on said circuit layer comprises
adhesively bonding said circuit layer to said spacer layer.
17. A machine method for providing, for dome switches of the type
wherein each dome switch comprises an approximately hemispherical
top surface having an apex, a complete dome switch assembly having a
circuit layer, a retaining cover layer, a spacer layer having a
plurality of openings for respectively receiving a plurality of dome
switches, a release liner, and an overlay layer, comprising the
steps of:
a. positioning on a machine table having a machine-movable surface
an initial assembly comprising
i. said circuit layer, circuit side upwards, and
ii. adjacent said circuit side of said circuit layer, said spacer
layer, having a spacer layer top surface;
b. situating said dome switches, affixed in a dome switch input
reel, over said machine-movable surface of said machine table;
c. machine-blanking respective said dome switches from said dome
switch input reel so that said dome switches drop into respective
said openings of said spacer layer;
d. placing said retaining cover layer, having a retaining cover top
surface, on said spacer layer top surface; and
e. placing said overlay layer, having an icon side, with said icon
side upwards, on said retaining cover top surface;
f. thereby making a complete dome switch assembly;
g. wherein said machine-movable surface is structured and arranged
for lateral movement in orthogonal directions.
18. A machine method according to claim 17 wherein:
a. each substep of said machine-blanking step comprises
i. moving said machine-movable table in such manner that said
machine-movable table locates for machine dome switch placement an
unfilled said opening not having therein a said dome switch; and
ii. machine-blanking a said dome switch in such manner as to allow
said dome switch to drop into said unfilled opening; and
b. said dome switch input reel is structured and arranged in such
manner that when said dome switches are blanked, said dome switches
drop into said spacer layer openings with said apex of said dome
switch facing up.
19. A machine method according to claim 18 wherein:
a. said retaining cover layer of said initial assembly is adhesively
attached to said spacer layer; and
b. said placing of said spacer layer on said circuit layer comprises
adhesively bonding said circuit layer to said spacer layer.
20. A machine method for providing, for dome switches of the type
wherein each dome switch comprises an approximately hemispherical
top surface having an apex, a dome switch sub-assembly having a
retaining cover layer, a spacer layer having a plurality of openings
for respectively receiving a plurality of dome switches, and a
release liner, comprising the steps of:
a. positioning on a machine table having a machine-movable surface
an initial assembly comprising
i. said retaining cover layer, having a retaining cover top surface,
and
ii. adjacent said retaining cover top surface, said spacer layer,
having a spacer layer top surface;
b. machine-blanking respective said dome switches from said dome
switch input reel so that said dome switches drop into respective
said openings of said spacer layer; and
c. placing said release liner on said spacer layer top surface;
d. wherein said machine-movable surface is structured and arranged
for lateral movement in orthogonal directions.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a dome switch assembly system. More
particularly, this invention concerns the manufacture of a dome
switch sub-assembly having a retaining cover, a spacer layer
encompassing a plurality of dome switches, and a release liner. Even
further, this invention concerns the manufacture of a complete dome
switch assembly having a circuit board, spacer layer encompassing a
plurality of dome switches, a retaining cover layer, and an overlay
layer.
2. Description of the Prior Art
Typically, dome switch assemblies or tactile dome switch arrays are
utilized to allow a user to manually input data into an electrical
device. Generally, such tactile arrays are in the form of a keyboard
or touchpad having certain alpha, numerical, or other designations
corresponding to a particular area on the tactile array. Upon the
user manually pressing these particular areas, dome switches in the
array are pressed against a circuit board, thereby allowing an
electrical signal to pass and thus be acted upon by the internal
processing system of the electrical device.
Generally, dome switch assemblies consist of the following layers: a
circuit board layer, a spacer layer, metal domes, a retaining cover
layer, and an overlay layer. Typically, each dome switch assembly is
individually assembled by hand, resulting in increased manufacturing
costs due to the required manual labor. It is also well known in the
art to provide dome switches which are sandwiched between a
retaining cover and a release liner wherein the domes are situated
on the retaining cover according to the configuration of the circuit
board as provided by the customer. A common problem with this method
is that the domes tend to migrate in the space between the retaining
cover and the release liner, resulting in delays and increased cost
to manually reposition the dome switches so as to conform to the
circuit board layout. Thus there exists a need for a dome switch
system that can be automatically assembled and which will solve the
problems encountered by the prior art.
OBJECTS OF THE INVENTION
A primary object of the present invention is to fulfill the
above-mentioned needs by the provision of an automatic machine
method to assemble either sub-portions or all of a dome switch
assembly. A further primary object of the present invention is to
provide such a dome switch system that is efficient, inexpensive,
and handy. Other objects of this invention will become apparent with
reference to the following invention description.
SUMMARY OF THE INVENTION
According to a preferred embodiment of the present invention, this
invention provides a machine method for providing, for dome switches
of the type wherein each dome switch comprises an approximately
hemispherical top surface having an apex, a dome switch sub-assembly
having a retaining cover layer, a spacer layer having a plurality of
openings for respectively receiving a plurality of dome switches,
and a release liner, comprising the steps of: positioning on a
machine table having a machine-movable surface an initial assembly
comprising such retaining cover layer, having a retaining cover top
surface, and adjacent such retaining cover top surface, such spacer
layer, having a spacer layer top surface; situating such dome
switches, affixed in a dome switch reel, over such machine-movable
surface of such machine table; machine-blanking respective such dome
switches into respective such openings of such spacer layer; and
placing such release liner on such spacer layer top surface.
In addition, this invention provides such a machine method wherein
such retaining cover layer of such initial assembly is adhesively
attached to such spacer layer. And it provides such a machine method
wherein such placing of such release liner on such spacer layer
comprises adhesively bonding such release liner to such spacer
layer. Also it provides such a machine method wherein each substep
of such machine-blanking step comprises: moving such machine-movable
table in such manner that it locates for machine dome switch
placement an unfilled such opening not having therein a such dome
switch; and machine-placing a such dome switch into such unfilled
opening. It further provides such a machine method wherein such dome
switch reel is structured and arranged in such manner that such dome
switches are blanked into such spacer layer openings with such apex
of such dome switch facing down; and, further, wherein such
positioning step and such placing step are both manually
accomplished.
Moreover, this invention provides such a machine method wherein each
substep of such machine-blanking step comprises: moving such
machine-movable table in such manner that it locates for machine
dome switch placement an unfilled such opening not having therein a
such dome switch; and machine-placing a such dome switch into such
unfilled opening; and such dome switch reel is structured and
arranged in such manner that such dome switches are blanked into
such spacer layer openings with such apex of such dome switch facing
down. And it provides such a machine method wherein such retaining
cover layer of such initial assembly is adhesively attached to such
spacer layer; and such placing of such release liner on such spacer
layer comprises adhesively bonding such release liner to such spacer
layer.
Even further, in accordance with a preferred embodiment thereof, the
present invention provides a machine method for providing, for dome
switches of the type wherein each dome switch comprises an
approximately hemispherical top surface having an apex, a dome
switch assembly having a circuit layer, a retaining cover layer, a
spacer layer having a plurality of openings for respectively
receiving a plurality of dome switches, and a release liner,
comprising the steps of: positioning on a machine table having a
machine-movable surface an initial assembly comprising such circuit
layer, circuit side upwards, and adjacent such circuit side of such
circuit layer, such spacer layer, having a spacer layer top surface;
situating such dome switches, affixed in a dome switch reel, over
such machine-movable surface of such machine table; machine-blanking
respective such dome switches into respective such openings of such
spacer layer; and placing such retaining cover layer, having a
retaining cover top surface, on such spacer layer top surface.
Yet additionally, this invention provides such a machine method
further comprising a last step of placing an overlay layer, having
an icon side, with such icon side upwards, on such retaining cover
top surface. And it provides such a machine method wherein such
retaining cover layer of such initial assembly is adhesively
attached to such spacer layer. Also, it provides such a machine
method wherein such placing of such spacer layer on such circuit
layer adhesively bonds such circuit layer to such spacer layer.
Moreover, this invention provides such a machine method wherein each
substep of such machine-blanking step comprises: moving such
machine-movable table in such manner that it locates for machine
dome switch placement an unfilled such opening not having therein a
such dome switch; and machine-placing a such dome switch into such
unfilled opening. Further, it provides such a machine method wherein
such dome switch reel is structured and arranged in such manner that
such dome switches are blanked into such spacer layer openings with
such apex of such dome switch facing up.
Yet in addition, this invention provides a machine method wherein
each substep of such machine-blanking step comprises moving such
machine-movable table in such manner that it locates for machine
dome switch placement an unfilled such opening not having therein a
such dome switch; and machine-placing a such dome switch into such
unfilled opening; and such dome switch reel is structured and
arranged in such manner that such dome switches are blanked into
such spacer layer openings with such apex of such dome switch facing
up. It further provides such a machine method wherein such retaining
cover layer of such initial assembly is adhesively attached to such
spacer layer; and such placing of such spacer layer on such circuit
layer comprises adhesively bonding such circuit layer to such spacer
layer.
Even further, in accordance with a preferred embodiment thereof, the
present invention provides a machine method for providing, for dome
switches of the type wherein each dome switch comprises an
approximately hemispherical top surface having an apex, a complete
dome switch assembly having a circuit layer, a retaining cover
layer, a spacer layer having a plurality of openings for
respectively receiving a plurality of dome switches, a release
liner, and an overlay layer, comprising the steps of: positioning on
a machine table having a machine-movable surface an initial assembly
comprising such circuit layer, circuit side upwards, and adjacent
such circuit side of such circuit layer, such spacer layer, having a
spacer layer top surface; situating such dome switches, affixed in a
dome switch reel, over such machine-movable surface of such machine
table; machine-blanking respective such dome switches into
respective such openings of such spacer layer; placing such
retaining cover layer, having a retaining cover top surface, on such
spacer layer top surface; and placing such overlay layer, having an
icon side, with such icon side upwards, on such retaining cover top
surface; thereby making a complete dome switch assembly.
Also, it provides such a machine method wherein each substep of such
machine-blanking step comprises: moving such machine-movable table
in such manner that it locates for machine dome switch placement an
unfilled such opening not having therein a such dome switch; and
machine-placing a such dome switch into such unfilled opening; and
such dome switch reel is structured and arranged in such manner that
such dome switches are blanked into such spacer layer openings with
such apex of such dome switch facing up. Even further, it provides
such a a machine method wherein such retaining cover layer of such
initial assembly is adhesively attached to such spacer layer; and
such placing of such spacer layer on such circuit layer comprises
adhesively bonding such circuit layer to such spacer layer.
Yet further still, in accordance with a preferred embodiment
thereof, the present invention provides, in a machine method for
blanking dome switches off a dome-switch feed reel to place a
respective such dome switch into an opening in a spacer layer
situated on a machine table having a machine-movable surface, the
step of reversing such dome switch input reel to present each such
dome switch for blanking in a position to place each such dome
switch in such spacer layer in an upside down position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view illustrating the layers
comprising the dome switch sub-assembly according to a preferred
embodiment of the present invention.
FIG. 2 illustrates a typical dome switch as used in the present
invention.
FIG. 3 is a perspective view illustrating the placement of a
retaining cover on an x-y table of an automatic machine.
FIG. 4 is a perspective view illustrating the placement of a spacer
layer on top of the retaining cover.
FIG. 5 is an elevation view illustrating the step of blanking the
dome switches into the spacer layer spaces.
FIG. 5A is a partial enlarged view, in elevation, taken from FIG. 5,
illustrating the blanking of dome switches according to the
embodiment shown in FIG. 1.
FIG. 6 is a partial top view of FIG. 5 (with the blanking station
shown in phantom detail for clarity) illustrating the dome switches,
in reel form, being blanked from the stamped sheet.
FIG. 7 is a perspective view illustrating the step of placing the
release liner on top of the spacer layer.
FIG. 8 is a partial section view, taken along lines 8--8 of FIG. 7
illustrating the individual layers comprising the dome switch
sub-assembly.
FIG. 9 is an exploded perspective view illustrating the layers
comprising the complete dome switch assembly according to another
preferred embodiment of the present invention.
FIG. 10 is a perspective view illustrating the placement of the
circuit board on the x-y table according to the embodiment shown in
FIG. 9.
FIG. 11 is a perspective view illustrating the placement of the
spacer layer on the circuit board according to the embodiment shown
in FIG. 9.
FIG. 12 is an elevation view illustrating the step of blanking the
dome switches into the spacer layer openings according to the
embodiment shown in FIG. 9.
FIG. 13 is a partial enlarged view, in elevation, taken from FIG.
12, illustrating the blanking of dome switches according to the
embodiment shown in FIG. 9.
FIG. 14 is a perspective view illustrating the placement of the
retaining cover on the spacer layer according to the embodiment
shown in FIG. 9.
FIG. 15 is a perspective view of yet another preferred embodiment
illustrating the placement of the overlay layer on the retaining
cover.
FIG. 16 is a top view of an electronic calculator incorporating the
embodiments of the present invention.
FIG. 17 is a sectional view taken along the section 17--17 of FIG.
16, illustrating the arrangement of the individual layers of the
present invention installed in an electronic calculator illustrated
in FIG. 16.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT AND THE BEST MODE OF
PRACTICE
FIG. 1 illustrates the dome switch sub-assembly 20 of the present
invention according to a preferred embodiment thereof. Shown is a
dome switch sub-assembly 20 consisting of a retaining cover layer
21, a spacer layer 22 having a plurality of spacer layer openings 23
for receiving a plurality of dome switches 24, and a release liner
layer 25. The dome switches 24 are sized according to customer size
specifications and are manufactured, in well known ways, from
approximately 0.09 mm thick stainless steel. In the present
invention, FIG. 2 illustrates that the dome switches 24 may be
exemplified by a hemispherical surface 27 having an apex 28 at its
uppermost portion. Contact tabs 29 are provided along the base of
the hemispherical surface 27 for providing an electrical contact
with a circuit board 30 (not shown in FIG. 2). Though applicant has
described the dome switch 24 according to the best embodiment, it
should be apparent to those skilled in the art that other shapes,
sizes, and configurations of dome switches may be used without
deviating from the spirit of the present invention.
Illustrated in FIGS. 3-8 are the preferred sequence of steps to be
performed in manufacturing the dome switch sub-assembly 20 of the
present invention. Though the figures illustrating the present
invention, and all embodiments hereof, show approximately
rectangular shapes for the individual layers, it should be
understood that other geometrical shapes may be used for the
individual layers without deviating from the spirit of the present
invention. As illustrated in FIG. 3, the first step consists of
manually placing the retaining cover layer 21, having a retaining
cover top surface 31 and preferably made of approximately
0.002-inch-thick polyester material, on the working surface 32 of a
typical x-y table 33, part of a typical automatic blanking system
(which includes the blanking station 42 and reels 38 and 39
illustrated in FIG. 4). Proper positioning of the retaining cover
layer 21 on the working surface 32 is achieved in a manner readily
apparent to one skilled in the art of such x-y tables. After the
retaining cover layer 21 is properly positioned, the spacer layer
22, having a spacer layer top surface 34, is adhesively affixed,
preferably manually, on the retaining cover top surface 31, as shown
in FIG. 4. The spacer layer is preferably made of a polyester
material having a thickness ranging from 0.002 inch to 0.013 inch
with a typical thickness of 0.007 inch. To secure the spacer layer
22 to the retaining cover layer 21, a coat of adhesive material 36,
preferably comprising a typical high temperature acrylic adhesive,
is applied between the two layers (as shown in FIG. 3).
FIG. 5 illustrates the next step in the manufacture of the dome
switch sub-assembly 20. Specifically illustrated is the retaining
cover layer 21 and spacer layer 22 placed on the working surface 32
of the x-y table 33. Positioned above the x-y table 33 are an input
reel 38 and an output reel 39. Typically, the dome switches 24 are
formed on a sheet of raw material in well known ways such as
stamping. After the step of forming of the dome switches 24 is
complete, the stamped sheet 40 containing the formed dome switches
24 is spooled onto an input reel 38 thereby placing the dome
switches in "reel form". As shown in FIGS. 5-6, the stamped sheet 40
is then passed through a typical blanking station 42 which is
positioned above the working surface 32 of the x-y table 33. In
operation, as the stamped sheet 40 passes through the blanking
station 42, an air actuated blanking die 43 separates the dome
switches 24 from the stamped sheet 40, thereby allowing the dome
switches 24 to drop into the spacer layer openings 23.
As shown in alternate enlarged detail in FIG. 5A, the input reel 38
is structured and arranged so that the hemispherical top surface 27
of the dome switches 24 faces toward the x-y table 33. This step
embodies herein a machine method wherein such dome switch input reel
is structured and arranged in such manner that such dome switches
are blanked into such spacer layer openings with such apex of such
dome switch facing down. In accordance with this arrangement, when
the blanking die 43 removes or blanks the dome switches 24 from the
stamped sheet 40 and places them into the spacer layer openings 23,
the apex 28 of dome switch hemispherical top surface 27 rests on the
retaining cover layer 21 as seen best in FIG. 8. Correct placement
of the dome switches 24 into the individual spacer layer openings 23
is accomplished by a typical x-y table 33 which is structured and
arranged to laterally move, according to a pre-programmed computer
algorithm, the working surface of the x-y table 32 in either the x
or y direction as indicated by the directional arrows in FIG. 6. The
use of the x-y table 33 thus allows for automatic positioning of the
correct spacer layer openings 23 under the blanking die 43. This
step embodies herein a machine method wherein each substep of such
machine-blanking step comprises moving such machine-movable table in
such manner that it locates for machine dome switch placement an
unfilled such opening not having therein a such dome switch; and
machine-placing a such dome switch into such unfilled opening. Any
scrap material remaining after the blanking process is then spooled
onto the output reel 39. Specifically illustrated in FIG. 6 is a top
view of the area of the blanking station 42 (with a portion of the
blanking station 42 shown in phantom detail for clarity) illustrated
and described with respect to FIG. 5.
FIG. 7 illustrates the final step in the assembly of the dome switch
sub-assembly 20. This final step consists of placing, preferably
manually, a release liner layer 25, preferably made of a paper
material, over the spacer layer top surface 34, thereby preventing
the dome switches 24 from being displaced from the spacer layer
openings 23 prior to customer receipt. In applicant's preferred
embodiment, the release liner layer 25 has a removable paper backing
which, when removed, exposes a surface having an adhesive coat 25a
(see FIG. 8). This surface is then placed on the spacer layer top
surface 34, thereby securing the dome switches 24 inside their
respective spacer layer openings 23. This step embodies herein a
machine method wherein such placing of such release liner on such
spacer layer comprises adhesively bonding such release liner to such
spacer layer. Upon receipt by the customer of the dome switch
sub-assembly 20, the customer simply peels the release liner 25 off
of the spacer layer 22, and attaches the dome switch sub-assembly 20
to a circuit board 30 (not shown in FIG. 7).
FIG. 8 is a partial sectional view, taken along lines 8--8 of FIG.
7, which shows the individual layers comprising the assembled dome
switch sub-assembly 20. Specifically illustrated is a retaining
cover layer 21 adhesively attached to a spacer layer 22, as
discussed. The spacer layer 22 is provided with a plurality of
spacer layer openings 23 sized to fit a plurality of dome switches
24 of various sizes and shapes, as shown. To ensure that dome
switches 24 are not displaced from their respective spacer layer
openings 23, a removable release liner 25 is adhesively attached, as
shown and as previously discussed, to the top surface of spacer
layer 22, as shown in the figures.
According to a preferred embodiment of the present invention, the
hereinbefore mentioned steps embody a machine method for providing,
for dome switches of the type wherein each dome switch comprises an
approximately hemispherical top surface having an apex, a dome
switch sub-assembly having a retaining cover layer, a spacer layer
having a plurality of openings for respectively receiving a
plurality of dome switches, and a release liner, comprising the
steps of: positioning on a machine table having a machine-movable
surface an initial assembly comprising such retaining cover layer,
having a retaining cover top surface, and adjacent such retaining
cover top surface, such spacer layer, having a spacer layer top
surface; situating such dome switches, affixed in a dome switch
input reel, over such machine-movable surface of such machine table;
machine-blanking respective such dome switches into respective such
openings of such spacer layer; and placing such release liner on
such spacer layer top surface.
According to an another preferred embodiment of the present
invention, a complete dome switch assembly 48 is provided as shown
in FIG. 9. Shown is a complete dome switch assembly 48 comprising
the following elements: a retaining cover layer 21; a spacer layer
22 having a plurality of openings 23 to receive a plurality of dome
switches 24; and a circuit board 30 used to provide the electronic
connection between the dome switches 24 and internal electronics.
FIGS. 10-15 illustrate the preferred sequence of steps to be
performed in manufacturing the complete dome switch assembly 48 of
the present invention. As shown in FIG. 10, the first step consists
of manually placing the circuit board 30, having a circuit board top
surface 49, on
the working surface 32 of a typical x-y table 33. After the circuit
board 30 is properly positioned, a coat of adhesive material 36,
preferably a high temperature acrylic adhesive, is applied to the
circuit board top surface 49. Next, a spacer layer 22, having a
spacer layer top surface 34, is adhesively affixed in the manner
previously discussed, preferably manually, to the circuit board top
surface 49, as shown in FIG. 11. This step embodies herein a machine
method wherein such placing of such spacer layer on such circuit
layer adhesively bonds such circuit layer to such spacer layer. The
spacer layer 22 is oriented on the x-y table such as to allow
accurate and correct placement of the dome switches 24 into the
spacer layer openings 23 as will be more fully explained with
reference to FIG. 12.
FIG. 12 illustrates the step of blanking the pre-formed dome
switches 24 into the spacer layer openings 23. According to the
preferred embodiment, the input reel 38 is structured and arranged
so that the hemispherical top surface 27 of the dome switches 24
faces away from the x-y table 33 (as best shown in enlarged
alternate detail in FIG. 13). This step embodies herein a machine
method wherein such dome switch input reel is structured and
arranged in such manner that such dome switches are blanked into
such spacer layer openings with such apex of such dome switch facing
up. And further, this step embodies in a machine method for blanking
dome switches off a dome-switch input reel to place a respective
such dome switch into an opening in a spacer layer situated on a
machine table having a machine-movable surface, the step of
reversing such dome switch input reel to present each such dome
switch for blanking in a position to place each such dome switch in
such spacer layer in an upside down position. The stamped sheet 40
passes under the blanking die 43 which removes or blanks the dome
switches 24 from the stamped sheet 40. As illustrated in FIG. 13,
the input reel 38 is structured and arranged so that the dome
switches 24 are blanked into the spacer layer openings 23 so that
the contact tabs 29 are at rest on the circuit board 30. Correct
placement of the dome switches 24 into the individual spacer layer
openings 23 is accomplished by a typical x-y table 33 which is
structured and arranged to laterally move, according to a
pre-programmed computer algorithm, the working surface of the x-y
table 32 in either the x and/or y direction as indicated by the
directional arrows in FIG. 6. The use of the x-y table 33 thus
allows for automatic positioning of the correct spacer layer
openings 23 under the blanking die 43. This step embodies herein a
machine method wherein each substep of such machine-blanking step
comprises moving such machine-movable table in such manner that it
locates for machine dome switch placement an unfilled such opening
not having therein a such dome switch; and machine-placing a such
dome switch into such unfilled opening. Any scrap material remaining
after the blanking process is then spooled onto the output reel 39.
As shown in FIG. 14, the last step in the assembly of the complete
dome switch assembly 48 consists of first applying a coat of
adhesive material 36, preferably a high temperature acrylic
adhesive, to the spacer layer top surface 34 (as shown in FIG. 11).
A retaining cover layer 21 is then adhesively affixed, preferably
manually, to the spacer layer top surface 34, thereby securing the
dome switches 24 within spacer layer openings 23. According to yet
another preferred embodiment of the present invention, an overlay
layer 51 having an icon side 52 on which is imprinted alpha,
numeric, or other icons representing the various electronic
functions or designations may be provided as shown in FIG. 15. The
overlay layer 51 is typically made of a polyester material and has
an approximate thickness of 0.007 inch. Incorporating the overlay
layer 51 into the complete dome switch assembly 48 consists of
applying a coat of adhesive material 36, preferably a high
temperature acrylic adhesive, to the retaining cover top surface 31
(as shown in FIG. 14). The overlay layer 51 is then adhesively
affixed, preferably manually, to the retaining cover top surface 31
so that the icon side 52 faces upward. This step embodies herein a
machine method further comprising a last step of placing an overlay
layer, having an icon side, with such icon side upwards, on such
retaining cover top surface.
FIG. 16 is a representational illustration of the dome switch
sub-assembly 20 and the complete dome switch assembly 48 installed
in an end product. Specifically illustrated is an electronic
calculator 53 having a dome switch-type keyboard or overlay layer
51. Shown in FIG. 17 is a section of the electronic calculator 53
specifically illustrating the individual layers comprising the dome
switch sub-assembly 20 and the complete dome switch assembly 48
enclosed by the calculator housing 54. Shown are an overlay layer
51; a retaining cover layer 21; a spacer layer 22 having a plurality
of openings 23 to receive a plurality of dome switches 24; and a
circuit board 30 used to provide the electronic connection between
the dome switches 24 and internal electronics.
In the present invention, the steps illustrated and described with
respect to FIGS. 10-15 embody herein a machine method for providing,
for dome switches of the type wherein each dome switch comprises an
approximately hemispherical top surface having an apex, a complete
dome switch assembly having a circuit layer, a retaining cover
layer, a spacer layer having a plurality of openings for
respectively receiving a plurality of dome switches, a release
liner, and an overlay layer, comprising the steps of: positioning on
a machine table having a machine-movable surface an initial assembly
comprising such circuit layer, circuit side upwards, and adjacent
such circuit side of such circuit layer, such spacer layer, having a
spacer layer top surface; situating such dome switches, affixed in a
dome switch input reel, over such machine-movable surface of such
machine table; machine-blanking respective such dome switches into
respective such openings of such spacer layer; placing such
retaining cover layer, having a retaining cover top surface, on such
spacer layer top surface; and placing such overlay layer, having an
icon side, with such icon side upwards, on such retaining cover top
surface; thereby making a complete dome switch assembly.
Although applicant has described applicant's preferred embodiments
of this invention, it will be understood that the broadest scope of
this invention includes such modifications as diverse shapes and
sizes and materials. Such scope is limited only by the below claims
as read in connection with the above specification. Further, many
other advantages of applicant's invention will be apparent to those
skilled in the art from the above descriptions and the below claims.
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