Note: Descriptions are shown in the official language in which they were submitted.
8 1 9
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IMPROVEMENTS IN OR RELATING TO INDICATORS AND PUSHBUTTONS
BACKGROUND TO THE INVENTION
The present invention relates to an illuminable
indicator or pushbutton, to members for such indicators and
pushbuttons, and to methods of making indicators or
pushbuttons.
Pushbutton switches, for example, are provided in a
variety of locations, such as in lifts. It is frequently
required to provide illumination thereto, for example, to
lndicate that the switch has been operated or to facilitate
use of the pushbutton. It is known to illuminate such
switches by providing an illuminated halo surrounding the
pushbutton. A construction of a pushbutton switch having
such a halo effect is described in our earlier UK Patent
No. 1456391.
It is also known to provide illuminable indicators,
for example, to show the current floor location of a lift.
Our UK Patent No. 2148574 shows such an indicator in which
materlal has been removed from an opaque cover plate to
form the indicia to be ~lluminated.
It ls, of course, useful to provide indicia on
pushbutton pressel plates and to arrange that these are
illumlnated. However, thls leads to complications in the
assembly of the pushbutton switches in that each pushbutton
switch has to have the required indicia on its pressel
plate. This means that the final func~ion of the
pushbutton assembly, including the indicia required on the
pressel plate, has to be known before the pushbutton
assembly is manufactured.
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SUMMARY OF THE INVENTION
According to a first aspect of the present invention
there is provided an illuminable indicator or pushbutton
member comprising a carrier, and a cover member
interengaged with said carrier, wherein said carrier
comprises a plate and interengaging means provided on said
plate wherein said cover member comprises a body member
having an external surface, and interengaging means
cooperable with those of said carrier to retain said cover
member on said carrier to extend over said plate, wherein
the cover member is arranged to be engaged with the carrier
subsequent to the mounting of the carrier in an indicator
or pushbutton.
Preferably, said carrier plate and said body member
are formed of a material which is pervious to light.
An indicator or pushbutton member of an embodiment of
the invention comprises the carrier and the cover member
and both of these may be standardised components. As the
cover member is arranged to be engaged with the carrier
subsequent to the mounting of the carrier in an indicator
or pushbutton, the indicators and pushbuttons can be
manufactured without reference to their final function.
When the indicator or pushbutton is to be mounted in its
use location, an appropriate cover member can be selected
and engaged wlth the carrler. The cover member selected
would carry the reguired indicia, or be plain, to suit the
location chosen for the indicator or pushbutton. In this
respect, the cover members are relatively small and low
cost components and a large number can be held in store,
the stored components having a wide range of differing
indicia. This enables the assembly of a large range of
different indicators and pushbuttons using the stored
components.
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Furthermore, the invention enables the provision of
both pushbuttons and indicators utilising the same cover
members. In this respect, the housing for the pushbuttons
and the indicators may be arranged to house a standardised
carrier, or two different types of carrier may be provided,
but each arranged to receive an identical cover member.
This also reduces the number of individual components which
need to be made and stored in order to offer a wide range
of final assemblies. The construction also enables an
indicator, for example, to be provided with halo
illumination as has become common with pushbuttons.
The material of said carrier plate and of said body
member may be translucent or transparent. Preferably, the
material is translucent. In this respect, it is preferred
that the aarrier plate and the body member both be made of
a polycarbonate plastics material.
Any appropriate cooperable interengaging means may be
provided on said carrier plate and on said body member.
For example, one of the carrier plate or body member may
have spring pro~ections arranged to engage within
respective recesses in the other of the body member or
carrier plate and~or spring clips may be formed on the
carrier plate or body member and arranged to engage with
rebatss and/or pro~ections formed on the body member or
carrier plate.
However, to facilitate the provision of a standardised
cover member for use in many different applications, it is
preferred that the body member comprises a substantially
planar wall on which said external surface is defined and a
peripheral skirt depending from said planar wall away from
said external surface. In this case it is convenient for
the interengaging means carried by said body member to
comprise resilient proJections pro~ecting from or formed
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within said peripheral skirt. The cooperable interengaging
means of said carrier preferably comprise slots extending
through said carrier plate into which a corresponding
resilient projection may be received.
Preferably, each said resilient projection is provided
with a flange arrange to clip onto or engage with part of
the respective slot in said carrier plate to retain the
cover member thereon.
The cooperable interengaging means are arranged to
retain the cover member on the carrier such that, once
assembled, the cover member cannot be released from the
front of an indicator or pushbutton in use.
In an embodiment, the interengaging means are arranged
80 that the cover member may be retained on said carrier in
a selected one of at least two positions. For example, two
oppositely arranged resilient projections may be provided
on said cover member whereas two pairs of opposed spaced
slots are provided in said carrier plate. The pro~ections
of the cover member may then be engaged with a selected one
of the pairs of slots and thereby engaged in a selected one
of two orientations.
The cover member may be of any peripheral shape
Preferably, the cover member is substantially circular or
ls substantially square ln perimetral shape.
In an embodiment, the plate of said carrier has at
least one aperture extending therethrough around which the
interengaging means on said plate are provided. In this
case, said cover member is retained on said carrier to
extend over said aperture or apertures.
Preferably, the carrier plate is provided with a
.,
~` 2123819
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single aperture only. Preferably the aperture is
substantially the same shape as the cover member. Thus,
the aperture may be substantially circular or substantially
square in shape.
The carrier has to be retained relative to a housing
of an indicator or a pushbutton and is therefore suitably
shaped to fit the housing and may carry appropriate fixing
or retention means. In this respect, in some circumstances
it may be sufficient to sandwich the carrier wi~h other
components to reliably retain it, and in other embodiments
a more positive retention may be preferred. Where the
carrier is to be provided in a pushbutton, for example, it
may also need to provide fixing or location means for
springC and/or switch members. Furthermore, a pushbutton
member may require guide means to control its movement
relatlve to a houslng. Of course, the retention, location,
and guide means may be shaped and configured as
appropriate.
In a preferred embodiment, the carrier plate has a
single aperture and has a rim which extends around said
aperture. Preferably, the shapes of said rim and of said
aperture are substantially the same. The slots forming the
interengaging means may be provided in said carrier plate
within isaid rim and around said aperture. Appropriate
retentlon, locatlon and gulde means extend externally of
said rim. Such means may extend substantially in the same
plane as the carrier plate and/or at angles thereto.
In a preferred embodiment, the external dimension of
the peripheral skirt of the body member of said cover
member is somewhat larger than the external peripheral
dimension of the cover plate. However, the external
dimension of the peripheral skirt is chosen such that the
peripheral skirt fits within the rim on said carrier plate.
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With this arrangement, the rim of the carrier plate may
form a peripheral shoulder surrounding the cover member in
the indicator member or pushbutton member. This
facilitates the provision of halo illumination around the
cover plate.
In known manner, the cover plate, which is preferably
made of stainless steel, is fixed to said body member
durlng moulding thereof. Preferably, any indicia are
formed by cutouts through the cover plate which become
filled with the material of the body member during moulding
thereof. Preferably the internal surface of the planar
wall of the body member is formed to define a plurality of
reflective surfaces to enhance the illumination effect.
The present invention also extends to an illuminable
indicator or pushbutton comprising a housing in which
illuminating means are received, said housing having a
front opening, and said housing being arranged to support
the carrier of an illuminable indicator or pushbutton
member as defined above in or proximate to the front
opening such that light from said illuminating means is
directed towards said carrier plate and said body member.
The housing may be configured as appropriate to enable
the lndicator or pushbutton to be mounted ln any required
wall or panel. Furthermore, swltches and/or other actuable
means may be carried and/or supported by the housing of the
pushbutton.
The illuminating means may be configured and supported
as required. For example, the illuminating means may
comprise a light bulb supported by a bulb holder, the bulb
being connected to electrical terminals supported by the
housing.
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~ 2123819
In an alternative embodiment, the illuminating meansmay comprise a number of LEDs appropriately mounted and
connected by way of an elec~rical circuit to electrical
terminals. In a preferred embodiment, the LEDs may be
mounted and supported on a printed circuit board.
Preferably, the bulb holder and the printed circuit
board are arranged to be interchangeably mounted in said
housing.
In an embodiment, the carrier ls retained relative to
the housing by fixing or retention means which are
sandwiched between components of the assembly to reliably
retain the carrier.
In an alternative embodiment, said carrier provides
fixing or location means for springs and/or switch members,
and wherein said carrier has guide means to control its
movement relative to said housing.
The present invention also extends to a method of
manufacturing an illuminable indicator or pushbutton, the
method comprising the steps of assembling illuminating
means in a housing having a front opening, supporting any
further requlred components on the housing, and supporting
the carrier of an illuminable member as defined above in or
proximate to said front opening, and, upon completion of
the assembly, engaging a selected cover member on said
carrier.
Preferably, the opaque cover plate of said cover
member comprises a selected indicia or is plain.
According to a further aspect of the present invention
there is provided a method of manufacturing an illuminable
indicator or pushbutton, the method comprising the steps of
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assembling illuminating means in a housing having a front
opening, supporting any further required components on the
housing, and supporting a carrier of an illuminable member
across said front opening, and, upon completion of said
assembly, engaging a selected cover member on said carrier,
said cover member carrying selected indicia or being plain.
Preferably, said cover member is selectively engaged
ln one of two possible orientations in relation to said
carrier.
The invention also extends to an electrical pushbutton
switch assembly comprising a housing having a base and an
upstanding peripheral wall, a pair of electrical switches
supported generally opposite to each other on said
perlpheral wall and each having an upstanding, reciprocal,
resiliently mounted, switching member, and a pushbutton
member, as defined above, supported within said peripheral
wall for reciprocable movement relative to said housing,
said pushbutton member having two switching pro;ections
each arranged in contact with a respective switching member
such that reciprocable movement of said pushbutton member
causes reciprocation of said switching members, wherein,
the housing and the pushbutton member are configured such
that the reciprocable movement of the pushbutton member is
within said housing, and such that the overall height of
the housing is generally substantially the same as the
height of each said switch including its switching member.
Reciprocation of the pushbutton member within the
housing between the switches is enabled by providing for
guiding of the reciprocal movement of the pushbutton member
at two opposed areas thereof only.
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g
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of th~ present invention will hereinafter
be described, by way of example, with reference to the
accompanying drawings, in which:-
Figure 1 shows a front view of a pushbutton switchassembly of the present invention,
Figure 2 shows a plan view of the assembly of Figure
10 1,
Figure 3 shows a section of the switch assembly of
Figures 1 and 2 taken along the line BB of Figure 2,
Figure 4 shows a section of the switch assembly of
Figures 1 and 2 taken along the line AA of Figure 2,
Figure 5 shows a perspective view from underneath of a
carrier plate of a pushbutton member of the switch
assembly, and
Figure 6 shows a perspective view from underneath of a
pressel member for interengagement with the carrier plate
of Figure 5.
DESCRIPTION OF PR~FERRED EMBODIMENTS
The drawings illustrate, and the present invention
will be described, with reference to a pushbutton switch
assembly. However, it should be appreciated that the
illumlnable pushbutton member provided in the switch
assembly may also be used as an illuminable indicator
member. In this respect, to provide an illuminable
indicator it is necessary only to fix the illuminable
indicator member relative to a housing.
The electrical pushbutton switch assembly shown in the
drawings is specifically designed for use in lifts but, of
course, may be used in any situations where pushbutton
operation is required. The particular switch assembly
2123819
-10-
illustrated is illuminable. AS compared with prior art
switch assemblies, the switch assembly described herein is
more shallow and considerably more compact. Furthermore,
the pushbutton member of the switch assembly described
herein comprises a standardised cover member carrying
selected indicia which may be fitted into the switch
assembly at the last stage of manufacture. The cover
member may be selectively oriented and may be selected to
carry the required indicia, or be plain, to suit the
location chosen for the pushbutton switch assembly.
Figure 1 illustrates a pushbutton switch assembly
mounted in situ. In this respect, the switch assembly has
a housing 2 which in use is mounted behind a door or panel
skin 4 (not visible in Figure 1) by way of mounting screws
6. The swltch assembly ls mounted so that a cover or
pressel plate 8 of a reciprocable cover or pressel member
10 is visible and accessible to a user. The pressel plate
8 ls surrounded by a halo of translucent material provided
by the pressel member 10 and by a carrier 12 therefor. In
u~e, the switch assembly is illuminated so that a halo of
illumination surrounds the pressel plate 8. In Figure 1,
the pressel plate 8 ls plain. However, illuminable indicia
can be provlded on the pressel plate 8 if required.
~5
As can be seen in Flgures 3, 4 and 6, the pressel
member 10 comprl~es a body member 14 whlch ls preferably
made o~ a translucent polycarbonate plastlcs material. The
body member 14 is substantially s~uare in shape and has a
substantially square, substantially planar base wall 16
from which an upstanding, peripheral skirt 18 depends. On
the front, external surface of the base wall 16 the pressel
plate 8 is fixed. In known manner the body member 14 is
fixed to the pressel plate 8 during moulding of the body
member. If the pressel member 10 is to carry indicia,
appropriate cutouts are made in the pressel plate 8 before
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the moulding operation. The translucent plastics material
then fills the cutouts in the plate 8 in known manner.
Preferably, the pressel plate 8 is made of stainless steel.
The pressel member lO is engaged with the carrier 12.
To facilitate this, on two sides the body member 14 of the
pressel member 10 is formed to provide resilient clips 20.
As can be seen in Figures 3 and 6, each clip 20 is a
resilient projection pro~ecting from and formed within said
peripheral skirt 18. Each projection 20 is provided with a
flange 22 for engagement with a respective slot in the
carrier 12.
. . .
The carrier 12 is also preferably made of a
translucent polycarbonate plastics material and is arranged
to guide the body member 14 for reciprocable movement
withln the switch housing 2 and also to enable the halo
lllumination around the pressel plate 8. Furthermore, it
is the carrier 12 which switches the individual switches
within the switch assembly.
A perspective view from underneath of the carrier 12
is shown in Figure 5. The carrier 12 comprises a
substantially square carrier plate 24. This carrler plate
has an external upstandlng rlm 26 as can be seen in Figure
4. Centrally of the plate 24 there is provided a
substantially square aperture 28 and ad~acent each side of
the aperture 28 there is provided a respective slot 30.
These slots 30 define interengaging means for cooperating
with the clips 20 on the body member 14. In this respect,
the pressel member 10 is generally provided with two
opposed clips 20. It will therefore be appreciated that
the pressel member 10 may be oriented selectively by
engaging the cllps 20 in a selected one of the two pairs of
opposed slots 30. When the pressel member 10 is engaged
with the carrier plate 24, by way of the clips 20, part of
2123819
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the translucent body member 14, and the rim 26 of the
carrier plate 24, extend outwardly of, and surround the
periphery of the pressel plate 8 as can be seen in Figure
4. This provides, in use, and in known manner, an
illuminable halo around the pressel plate 8. This,
together with the engagement between the flanges 22 and the
slots 30, also ensures that the pressel member 10 cannot be
removed from the switch assembly from the front thereof.
~he carrier plate 24 is guided for reciprocating
movement within the housing 2 by guide means 34 provided on
two opposed surfaces of the carrier plate 24. As indicated
ln Figures 2, each guide means 34 comprises an elon~ate
channel member depending from the carrier plate 24 and
havlng a base surface formed between two upstanding walls
36 defining longitudlnally extendlng pro~ections. The
pro~ections 36 are recelved in corresponding longitudinally
extending recesses (not vislble) ln the housing 2 to guide
the carrier 12 for reciprocal movement along the
longitudinai axis of the switch assembly.
on its other two sides, the carrier plate 24 is
provided with switching pro~ections 40. Each switching
proJection 40 ls formed by a flange extending substantially
ln the plane of the carrier plate 24, and extending along
the respective side of the carrier plate 24. Each said
flange carries a protuberance 42 for contacting a plunger
of an lndlvidual swltch and a pro~ectlon 44 for locating a
bias spring 62 (Figure 4). In this respect, in known
manner depression of the pressel member lO is arranged to
cause depresslon of the carrier 12 whereby plungers of the
lndlvidual switches carrled by the housing 2 will be
depressed, by way of the protuberances 42. When the
pressure ls released, bias springs located by the
pro~ections 44 will push the carrier 12, and hence the
pressel member 10 to the outward rest position, the
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plungers also being biassed to be returned by spring force.
One of the individual switches 50, which is a normally
closed switch, of the pushbutton switch assembly, can be
seen in Figure 3. The switch 50 is a substantially
conventional construction and comprises a moveable contact
52 normally held against individual fixed contacts 54 by
way of a spring 56. The moveable contact 52 is connected
to the spring 56 and also to a plunger 58. The plunger 58,
which is the switching member of the switch 50, projects
upwardly to contact the underside of one of the
protuberances 42 of the carrier 12. It will be appreciated
that depression of the plunger 58 will open the contacts
52, 54 and move the moveable contact 52 into contact with a
lower contact 60.
The switch assembly shown in the drawings is
particularly shallow and compact. In this respect the
overall height of the switch assembly is generally
substantially the same as the overali height of an
individual switch 50 when its plunger 58 is in its upper
rest position. All of the necessary reciprocating movement
of the carrier 12 takes place within the housing 2 and this
leads to the compact construction illustrated.
The compact construction is also enabled because the
carrler 12 ls gulded for reclprocating movement along two
only of lts sldes. Thls means that no gulding function has
to be provided on sides of the carrier 12 which contact the
swltch plunger 58 and the bias springs 62. Guidance can be
provided at two opposed areas of the carrier 12 only
because of the provision of the channels 34, the
longltudlnally extendlng walls 36 of which are each
received within a respective recess in the wall of the
housing 2. These recesses extend over substantially the
entire height of the housing 2 so that the carrier 12
212~19
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remains guided irrespective of its location along the
height of the housing 2. Preferably, the recesses are
defined between projecting surfaces of the housing 2 which
are also arranged to abut against the base of the
respective channel 34. This ensures that there is no
ability for twist to be introduced into the xeciprocating
movement of the carrier 12.
The manner in which the housing 2 is constructed also
enables it to be made compact. In this respect the housing
2 is preferably moulded from a polycarbonate plastics
material and is moulded in two parts. The first part is a
substantially planar base 70 which is integrally formed
with part of a housing 72 for each of the two switches 50.
In this respect, the switch housings 72 each have a clipped
on side wall 74 and are generally rectangular. The
housings each pro~ect upwardly of the base 70 on two sides
thereof.
In its central region the base 70 holds a bulb 80
carried on a bulb holder 82 for which appropriate
electrical terminals 84 are also provided. The bulb 80
extends substantially centrally within the housing 2 and
provides lllumination directed at the underside of the base
wall 16 of the body member 14 of the pressel member 10. In
the embodiment illustrated, the bulb holder 82 also carries
a re1ector 90 to surround the bulb 80 and direct the
li~ht. If required, the bulb holder 82 with its bulb 80
and terminals 84 may be replaced by an illumination printed
circuit board carrying LEDs and appropriate electrical
terminals.
To complete the formation of the housing 2 the base 70
is engaged with a moulded body 100. The body 100 is also
preferably moulded from a polycarbonate plastics material.
This body 100 is a generally rectangular hollow member
- ~ 21 23819
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i
having a perimeter rim. On two sides the interior surface
of the perimeter rim is formed with the necessary
longitudinally extending recesses for receiving the walls
36 of the channel members 34 of the carrier 12 to provide
the necessary ~uidance. The body 100 is also formed with
bores or apertures through which the plungers 58 extend. A
central bore is also provided through which the bulb 80
proJects. The body 100 is also formed with locating points
for the bias springs 62. The body 100 and the base 70 are
interengaged such that the perimeter rim of the body 100
and the switch housing 72 together define a generally
upstanding peripheral wall of the housing 2, and a front
opening in which the pressel member 10 is mounted.
It will be appreciated that the switch assembly having
two plunger operated switches controlled by the depression
of a pressel member 10 is substantially conventional in the
functionlng components provided and in its manner of
operation and so the operation of the swltch assembly will
not be further described.
It will be appreciated that modifications in and
variations to the embodiments specifically described and
lllu8trated may be made within the scope of this
application.
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