Note: Descriptions are shown in the official language in which they were submitted.
CA 02270042 1999-04-27
RESILIENT SWITCH COVER WITH INTEGRAL ACTUATOR BUTTON
Field of the Invention
This invention relates to the field of resilient covers for electrical switch
plates,
and in particular, switch plates which contain one or more flush mounted push-
button type
electrical switches. It is a further object to provide a switch actuator
button having a head
portion raised above the resilient switch cover and an actuator portion which
extends inwardly
of the cover to engage an electrical switch.
Background of the Invention
The use of a flexible membrane to cover electrical switches is in common use,
for example, in calculator and telephone keypads. Such covers are
advantageously utilized as
an effective means of protecting the switches from dirt and moisture.
Currently, each switch
located beneath the flexible switch cover is generally identified by printing
illustrations on the
switch cover at the switch locations or by embossing the flexible cover to
create raised areas at
the switch locations. These techniques have limited application since
embossing of the
flexible cover is limited to 1.5 times the thickness of the material and
provide very limited
tactile feedback and illustrations printed upon the face may be rendered
obscure by soiling. In
addition the presently used means of switch identification requires that the
operator be able to
visually confirm the switch location.
It is an object of the present invention to provide an actuator, generally in
the
form of a button, which is riveted to the resilient switch cover and which is
raised above the
surface of the switch cover. The raised surface will then provide sufficient
tactile feedback to
the operator to permit positive identification of the switch locations, under
either lighting
conditions that would obscure printed surface illustrations, or work
conditions where a
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CA 02270042 1999-04-27
machinery operator must keep his eyes focussed on the work-end of the
machinery without
being distracted by looking for switch identifiers.
It is a further object to provide a switch actuator button having a head
portion
raised above the resilient switch cover and an actuator portion which extends
inwardly of the
cover to engage an electrical switch.
Summary of the Invention
The resilient switch cover with integral actuator button of the present
invention
includes a weatherproof flexible membrane, which may be resilient. The
membrane is
trimmed to match the shape of the electrical switch plate so as to be mounted
to an upper
surface thereof. The face of the membrane may have printed thereon an image
generally in the
form of circular outlines which identify the precise location of the
electrical switches aligned
with, and mounted to the underside of the electrical switch plate. A portion
within the circular
switch identification outline is removed to form an aperture. The aperture
permits the
attachment of a switch actuator button. The underside of the resilient cover,
that is, the side
which is affixed to the upper surface of the electrical switch plate, is
coated with an adhesive.
The adhesive adheres the switch cover to the switch plate.
A switch actuator button is mounted to the switch cover in the manner of a
rivet. The button has an actuator shaft extending perpendicularly from the
button. The shaft
protrudes through the switch cover. Surrounding the actuator shaft and
integrally formed with
the head is a relatively thin-walled sleeve which is spaced radially outwardly
from the shaft.
The outer diameter of the thin-walled sleeve is sized to permit it to be
inserted through the
aperture formed in the resilient switch cover. The diameter of the head
portion of the button is
greater than the diameter of the aperture formed in the resilient switch cover
so that upon
deformation of the thin-walled sleeve by heat and pressure the actuator button
is firmly
affixed, in the manner of riveting, to the resilient switch cover.
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Riveting of the actuator button to the resilient switch cover leaves the
button
portion raised or protruding above the upper surface of the switch cover for
ease of tactile
location of the button by the operator. The actuator shaft, extends so as to
engage a
corresponding electrical switch of the electrical switches mounted to the
underside of the
switch plate.
In summary, the switch cover of the present invention includes a resilient
flexible membrane having an outer surface and an opposite inner surface for
mounting onto a
switch plate. The flexible membrane has at least one aperture therethrough,
and may have a
plurality of apertures corresponding to the number of switch controls desired.
Each aperture
has a switch actuator button snugly journalled therethrough and mounted to the
membrane so
as to leave an outer portion of the button protruding above the outer surface
of the membrane
for tactile feedback to an operator. An inner portion of the button extends
generally
perpendicularly from the inner surface of the membrane for actuating
engagement with a
corresponding switch actuator on the switch plate. Advantageously the button
is mounted to
the membrane in the manner of a rivet. The switch actuator may be a plunger
cooperating with
a switch. In the preferred embodiment, the outer portion of the button has a
diameter larger
than a corresponding diameter of the aperture in the membrane, and the inner
portion of the
button comprises an elongate plunger shaft co-axial with a deformable sleeve
enclosing the
plunger shaft. The deformable sleeve has a diameter corresponding to the
diameter of the
aperture for snug journalling of the inner portion of the button through the
aperture. The
sleeve is deformable, for example in the manner of a rivet, for the mounting
of the button to
the membrane. Thus, the deformable sleeve may be radially outwardly spaced
from the
plunger shaft.
In one aspect of the present invention the outer surface of the membrane has a
visual indicator thereon indicating location of the outer portion of the
button. The visual
indicator may be an encircling contrasting mark on the outer surface of the
membrane
encircling the upper portion of the button.
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CA 02270042 2003-O1-23
In a further aspect, the upper surface of the mernbrane has a raised annular
surface thereon generally surrounding the aperture in the membrane.
Advantageously the
annular surface and the aperture in the membrane are co-axial. Also, the
switch plate may
have an annular depression corresponding to the annular surface when the
membrane is
mounted on the switch plate.
Brief Descn~ on of the Drawings
Figure 1 is a perspective of the resilient switch cover with actuator buttons
in
place.
Figure 1a is the switch cover of Figure 1 without actuator buttons.
1 S Figure 2 is an enlarged sectional view along line 2-2 of Figure 1.
Figure 3 is an enlarged sectional view of the actuator button, before riveting
of
the button to the switch cover.
Figure 3a is the actuator button of Figure 3, after riveting of the button to
the
switch cover.
Detailed Description of the Preferred Embodiment
As illustrated in Figures 1, la, 2, 3 and 3a, resilient switch cover 10 is a
thin
flexible membrane. The membrane may be of fabric or of other material known in
the art.
The membrane may be readily trimmed to fit the shape of an electrical switch
plate 12. The
upper face 14 of the switch cover 10 has an image 16 printed thereon, which is
generally a
circular or polygonal outline. The image 16 identifies the location of a push-
button type of
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electrical switch 18 which is mounted to the underside 20 of the switch plate
12. The actuator
22 of switch 18 is accessible through an aperture 24 formed through switch
plate 12. An
annular recess 26 is formed on the upper surface of switch plate 12,
surrounding aperture 24.
The diameter of recess 26 generally matches the diameter of image 16 printed
on the face of
switch cover 10. Switch cover 10 is secured to the upper face of switch plate
12 by an
adhesive 11, which covers the lower mating surface of cover 10 except for the
areas generally
opposite to the images 16 which identify the locations of switches 18. A hole
30 is formed in
switch cover 10, within each printed image 16, which permits a switch actuator
button 32 to be
attached.
As may be seen in Figure 3, actuator button 32 has an actuator shaft 34 with a
button or head portion 36 formed at one end. A thin-walled sleeve 38 is
integrally formed
with head portion 36, to extend outwardly from head 36 parallel to and
radially spaced
outwardly from the actuator shaft 34.
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The diameter of sleeve 38 permits it to be inserted through hole 30 in switch
cover 10. Head portion 36 of actuator button 32 is larger in diameter that
hole 30 which
ensures that head portion 36 of button 32 is retained on the upper surface 14
of switch cover
10. Once positioned through hole 30 in cover 10, the actuator button 32 may be
riveted in
place onto switch cover 10 by applying heat and pressure to thin-walled sleeve
38 in direction
"A" generally parallel to the longitudinal axis thereof as seen in Figure 3a
to deform sleeve 38
against the underside of the resilient switch cover 10. With sleeve 38 so
deformed and
mounted onto cover 10, switch actuator shaft 34 extends well below cover 10.
When switch
cover 10 is applied to switch plate 12, shaft 34 extends through aperture 24
formed in switch
2S plate 12 to contact switch actuator 22 of electrical switch 18.
Recess 26 formed in the upper surface of switch plate 12 allows resilient
switch
cover 10 to be depressed slightly below the upper surface of plate 12 when
actuator button 32
is pushed downward to operate switch 18. As may be seen in Figure 2, a raised
or domed area
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CA 02270042 2003-O1-23
40 can be formed surrounding the button 32 within the area of image 16 on
cover 10. This
domed area 40 is advantageous when controller 22 of switch 18 is a plunger
rewiring a greater
plunger stroke distance in direction "B".
Alternatively, the domed area 40 may be inverted so as to, in its normal
position, extend slightly below upper surface 14 of resilient switch cover 10.
In either case the
head portion 36 of button 32 will protrude above surface 14 of cover 10 to
thereby enable an
operator to obtain tactile feedback for the positive identification of switch
locations.
As will be apparent to those skilled in the art in the light of the foregoing
disclosure, many alterations and modifications are possible in the practice of
this invention
without departing from the spirit or scope thereof. Accordingly, the scope of
the invention is
to be construed in accordance with the substance defined by the following
claims.
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