Note: Descriptions are shown in the official language in which they were submitted.
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VIsRATOR ALERTERS
This invention relates to vibrator alerters.
Vibrator alerters are known devices for use in
portable ~.ol P~llnnPc and in portable pagers . In the known
s cons~ructions, an electric motor: has a rotatable eccentric
mass which sets up a vibrational frecluency when the motor :~
is operated. There are various disadvantages associated --~
with known vibrator alertsrs. The electric motors with
their eccentric masses tend to be inordinately expensive
0 for their particular purpose and require a large amount of
electrical power for their operation. The life expectancy
of these motors is also small in contrast to the life
expectancy of tPl P~htlnPq or pagers to which they are
fitted. There is also a potential danger in the use of the
15 known vibrator alerters which of necessity are battery
operable. Commutators which are used in the electric
motors are known to generate and emit sparks. This
provides the potential for explosions in the presence of ~:
hydrogen which may be give~ of f by the batteries
20 themselves.
The present invention seeks to provide a vibrator
alerter which minimizes or avoids the above problems.
Accordingly, the present invention provides a
vibrator alerter for a portable communications device
2s comprising a first mass lnc~uding a diaphragm, a second
mass, and a solenoia with a rigid body of the solenoid
forming part of the second mass, the diaphragm having a
marginal edge secured to the second mass and being provided
with a stiffness to urge the first and second masses into
30 normal relative positions, the solenoid acting between the
first and second masses and against the diaphragm stiffness
to cause, upon solenoid energization, reciprocating
m.,v of one mass relative to the other, the movable
mass being of a size such as to limit its reciprocating
3s movement to fre~uencies below audio freguencies and to
provide a tactile vibrational characteristic.
~135 i34
The above vibrator alerter according to the
invention preferably operates at frequencies of
reciprocation considerably below volce frequency ranges.
For instance, voice frequencies commence at about 120 EIz
s and up to perhaps 12 kHz. In this present invention,
frequencies around 50 Hz are suitable for the tactile
vibrational characteristic and frequencies within the
resonance frequency range of the alerter are convenient,
such as between 50 and 80 Hz.
A vibrator alerter accordiny to the invention has
a long operational life and is relatively inexpensive. In
addition, vibrator alerters according to the invention may
be constructed which take minimal power and may easily be
operated by a battery producing for instance 1. 5 volts .
Further, a vibrator alerter of the invention is operable
without the potential to generate sparks and thus there is
no risk in using such an alerter in the presence of
hydrogen generated by a battery within a portable
communication device.
In a vibrator alerter according to the invention,
either the first m.ass including the diaphraym may move ~-
reciprocally or the second mass ; n~ i n~ the solenoid body
may provide the movement. Preferably, however, it is the
first mass which provides the v t and a weight secured
2s to the diaphragm ensures that the first mass is
sufficiently large to produce the required vibrational
frequency of the first mass and provide the required _
tactile vibrational characteristic. rhe size of the
vibrator alerter must be convenient for use within a
portable communication device. ~m-l ln,~qs in size is thus
an important consideration. It has been ~ound that with
the solenoid body operating also as a housing ~or the
diaphragm, outside diameters of around 40 mm or less for
the solenoid body are suitable for alerters according to
the invention. In one construction with an outside
diameter o~ 28 mm, a 3 to 5 gram weight added to the
diaphragm has been sufficient to produce the desired
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tactile vibrational characteristic with sufficient
vibrational strength to be immediately noticeable by a
person carrying the device, for ~instance, either in a
pocket or upon a belt.
s It has been found that with vibrator alerters ~ --
according to the invention and operating at tactile - -
vibrational frequencies around 50 Hz that there may be a
tendency for the diaphragm to vibrate in azimuthal modes --
during operation and such a ph~n( ~,n may delete~iously
lo affect the tactile response. It is also preferable
therefore for the alerter to include an ~1 ignm~nt control
which rn~inti~inC: axial alignment of the solenoid elements
and ~hich thus ensures that the diaphragm is not allowed to
twist out of axial alignment. The alignment control may
comprise a guide member for sliding reception axially
within a guide passage of a support, for instance the body
of a portable commllnication aevice, when the solenoid body
is carried ~y such a device. Alternatively, the alignment
control may comprise a plurality of radially extending
20 fingers spaced around the axis of reciprocatLng v~ t of
the diaphragm. ~uch fingers are resiliently flexible in an
axial direction and are balanced, while being secured at
inner ends to the diaphragm, the diaphragm having a
marginal edge secured to the second mass and being provided
2s with a stiffness to urge the first and second masses into
normal relative positions, so as to resist axial r- v. t
in the diaphragm in one direction of its reciprocation
while axial alignment of the diaphragm is assured.
The invention also includes a portable
30 ~ ni~tion device comprising a body, a storage region
for an electrical battery, and a vibrator alerter
comprising a first mass ~n~ ;n~ a diaphragm, a second
mass, and a solenoid with a rigid body of the solenoid
forming part of the second mass, the solenoid acting
3s between the first and second masses and against the
diaphragm stiffness to cause, upon solenoid energization,
reciprocating ,v~ t of one mass relative to the other,
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the movable mass being of a size such as to limit its
reciprocating movement to re(luencies below audio:
frer~uencies and to provide a tactile vibrat~ional
characteristic .
s Embodiments of the invention will now be
described, by way of example, with reerence to the
accompanying drawings, in which:-
Figure 1 is a plan view of a portable
communication device in the form of a portable tPl PpllnnP;
lo Figure 2 is a cross-sectional view through the
telephone of the first embodiment taken along line II-II in
Figure l;
Figure 3 is a cross-sectional view through a
vibrator alerter forming part of the portable tPlP~hnnP of
the first embodiment and taken along the same cross- - -
sectional line as Figure 2 but to a much larger scale;
Figure 4 is a view similar to Figure 3 of a
vibrator alerter forming part of a portable telephone
according to a second embodiment;
Figure 5 is a view of part of the alerter of
Figure 4 taken in the direction of arrow V in Figure 4; and
Figure 6 is a vlew similar to Figure 3 of a third
embodiment .
In a first r~l n7iir t, as shown by Figures 1 and
2s 2, a portable tPl PphnnP 10 has a body 12 with upper and
lower substantially planar sides 14 and 16 as shown in
Figure 2 . The portable t.ol P~hnnP is of such a size that it
may be held in one hand of the user or may be kept within a
user~ s pocket or upon a belt of the user when an
appropriate clip (not shown) is provided upon the body. As
shown by Figures 1 an~l 2, the tlolP~hnnP 10 has a speaker 18
mounted at one end and a microphone 20 at the other end,
the speaker and microphone both facing outwardly from the
side 14. AS shown by Figure 2, within the body 12 is
3s disposed a storage region ~or a battery 22 of 1.5 volts, a
circuit pack or packs 24 for operation of the t~l PphnnP and
also a vibrator alerter 26 which, as will be descri~ed, is
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secured to the side 16 of the body 12. Alternatively, the
speaker, microphone battery storage region a~d circuit
packs are secured in other locations within the body 12.
As shown in greater detail in Figure 3, the
s vibrator alerter 26 comprises a diaphragm housing 28 of
circular plan, the housing having a frusto-conical portion
30 tPrm;n~tin~ in a closed narrow end 32 and terminating at
its other end in a short cylindrical portion 3 4 with an
annular end flange 36. A reciprocal diaphragm 38 is
lo attached by a marginal edge to the cyLindrical housing
portion 34. The diaphragm 38 is of shallow frusto-conical
shape from its marginal edge and has a small diameter end -- ~
at which it is provided with an axially extending conductor
wire coll 40 of a solenoid. The solenoid is completed by a
body formed integrally with the housing 28, the solenoid
body i n~ di n~ an integral plunger 44 which exte~ds into
the coil 40. The coil 40 is electrically connected to the ~ :
circuit packs 24 by means of conductor wires 46 extending
from the coil and outwardly from the alerter in the region
of the cylindrical body portion 34. The diaphragm housing - -
28 and body 12 provides a stationary mass o~ the alerter
and is suitably secured by the annular flange 36, in a
manner~ not shown, to the side 16 of the body 12 . A second
mass which is intended to reciprocate within the housing 28
2s comprises the diaphragm 38 and the speaker coil 40. The
second mass has a normal axial position relative to the
housing 28, this normal position being attained by the
stiffness of the diaphragm 38.
The second mass is required to reciprocate at a
low frequency so as to provide tactile vibrational
characteristics and for this purpose the mass should be
sufficiently great to el~sure that this vibrational
characteristic is achieved. To produce the required mass,
a weight is provided upon the diaphragm 3 8 . ~his weight is
3s in the form of a disc 50 of approximate weight between 1
and 5 grams and which is attached concentrically to the
underside of the small diameter end of the diaphragm 38,
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i . e. on the opposite side from the coil 40 as shown by
Figure 3. The alerter is also provided with an alignment
control for Tr~-inti~;nin~r axial alignment of the solenoid
elements during operation preventing vibration in azimuthal
s modes which could detract from the desired tactile
vibrational characteristics. In the embodiment shown by
Figure 3, the alignment control comprises a guide member in
the form of a narrow shaft 52 which extends along the axis
of reciprocation of the diaphragm and downwardly from the
lo weight 50 This shaft 52 is slidably received within a
guide passage 54 formed in the wall 16 of the housing 28.
In operation, with the person carrying the
portable t~l PrhnnP either in his pocket or upon a belt as
desired, immediately an incoming call is received by the
5 telephone, then the coil 40 becomes energized to cause
reciprocating movement of the diaphragm 38 which is ~-
normally restrained to its normal lower axial position when
viewed in Figure 3 by its own stiffness referred to above.
As will be seen from the above explanation because of the
incorporation of the weight 50 to complete the mass of the
diaphragm and coil, the diaphragm has a reciprocating
frequency characteristic which is exceedingly small and may
operate within the r,,q~n~nr-e frequency of the diaphragm,
i . e. between 50 and 80 Hz or slightly below that range.
2s ThiS vibrational frequency is below that for audio use and
lies within the tactile range of frequencies. It follows
therefore that reciprocating v, t of the diaphragm and
the rest of the movlng mass is clearly felt by the user to - -
indicate to him that an incoming call is taking place. In
addition, the tactile stimulus characteristics can be
varied (by varying the electrical stimulus) for selected
alerting conditions.
As may be seen from the first embodiment, the
operation of the vibrator alerter is somewhat similar to
3s the operation of a conventional microspeaker, the basic .=
dif ference being that -it operates at a much lower frequency
than a microspeaker and provides tactile instead of audio
2 ~
- 7 --
signals. The cost of the vibrator alerter is relatively
small and no sparks can be emitted which could cause an
explosion problem in the presence of hydrogen which may be
given of f by the battery . Also, as may be seen from the
s embodiment, the vibrator alerter is operable with low power
batteries and is comparable for its energy requirements to
a conventional microspeaker. Another advantage with the
construction of the vibrator alerter is its size and shape.
The maximum dimension for a vibrator alerter for commercial
o application, i . e . its diameter ne~d be relatively small
while producing suitable tactile properties. For instance
in the first embodiment, the alerter has an outside
diameter of about 28 mm or less as referred to above. With
such a ~lii tPr the height of the total alerter i.e.
between the flange 36 and the end 32 of the housing is
excessively small, i . e. at or below S mm, and this enables
a portable telephone to be constructed which is extremely
thin between the sides 14 and 16 and thus may comfortably
fit within a user's pocket.
In a second ~ im~nt., in a portable t~l PrllnnP of
otherwise similar construction to that described in the
first Pmh~;r~nt, a vibrator alerter 60 i~ included as
shown in Figure 4. In this construction which is otherwise
similar to that of the alerter 26 and has the same
2s reference numerals for similar parts, the ~ nmPnt control
in the form of the shaft 52 is replaced by the use of a
plurality of radially Pl~tPnr~ing fingers 62 relatively
disposed around the axis of reciprocation of the diaphragm.
These fingers 62 resiliently flex in an axial direction and
are se-curad at ~heir inner ends to the weight 50 in close ~=
proximity to ei~ch other so as to resiliently resist axial
~vi t of the diaphragm in an upwards direction, i . e . in
the same direction in which resistance is offered by the ~_
stiffness of the d~aphragm itself. As shown by Figure 5,
3s the fingers are conveniently formed integrally with a
radially outer ring 64 hy a pressing or cutting operation
in which the f ingers occupy equal arcs of generation around
-
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the axis of reciprocation, the fingers being formed by two
crossing slits 66 which provide each finger substantially
in the form of a quadrant of a circle. Construction is
such that there is perfect balance in the loading applied
s by the fingers so that the fingers act upon the weight 50
and upon the diaphragm 38 to prevent any azimuthal mode of
vibration of the diaphragm during operation. As shown by
Figure 4, the ring 64 is held by the flange 36 against the
side 16 of the body 12.
It may be found that the shortness of the lengths
of the f ingers in such an arrangement causes a lack of
flexibility for their desired use. In such an event, the
ring 64 may be made of larger diameter so as to stand
radially outwardly from the annular fIange 36 and be
5 secured separately to the side 16. In this case (not
shown) the fingers would be of narrow construction and
would be spaced apart to enable them to pass through gaps
formed around the annular flange 36 of the housing 28.
In a third embodiment as shown by Figure 6, a
20 portable ~ phnnf~ is of substantially the same
construction as described in the first embodiment. In this
pa~ticular embodiment, a vibrator alerter 70 is of similar
construction generally to that described in the first
embodiment except that in the third embodiment it is the
2s mass including the diaphragm 38 which is secured to the
side 16 of the housing thereby enabling reciprocation of
the diaphragm housing 71. This is effected by securing the
center region of the diaphragm 38 to the housing 16 through
a spacer 72 so as to provide clearance for the housing 71
30 to allow for its reciprocating movement. In this case the
housing 71 is itself provided with a weight 74 upon its end
76 so as to increase the total mass thereby lowering the - ~
frequency of operation to the tactile vibrational fre~uency
characteristic which is required for this particular
~5 purpose.
While the above embodiments have been described
with reference to a portable t~ phnn~, vibrator alerters
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g
according to the invention are su~table ~Qr use upon any ~ ~`
type of portable communication device. In essence
there~ore any vibrator alerter and particularly those
described in the above embodiments may also be suitably
S used upon pagers instead o~ upon portable telephones.
