Note: Descriptions are shown in the official language in which they were submitted.
2'~J~3
HINGE APPARATUS FOR FOLDABLE RADiOTELEPHONES
Field of the Invention
This invention relates generally to hinged housings
for miniature electronic equipment and more particularly
to ~oldable radiotelephones which utilize hinged housings
for folding elements.
Background of the Invention
Portable, cellular phones are increasingly utiiized to
permit a user to communicate telephonically over a
wireless system at virtually any location. The portable
telephone transmits a low wattage, radio frequency signal
2 0 to a receiving sta~ion whereat connections are provided
with conventional telephone systems. Numerous receiving
stations are spaced apart at fixed locations in an area to
receivs the signals transmitted by the portable telephone
as the portable telephone is relocated throughout the area.
Telephones utilizing two housing elements connected
with some type of hinging mechanism, are common in
wireline telephone sets and landline wireless extension
phones and have become more common in portable oellular
radiotelephones. This folding arrangement allows for the
3 0 telephone to be more compact when the two housings are
folded upon themselves.
Some radiotelephones which utilize this type of
design have most of the electronics within the larger of
the two housings. The smaller housing, which will be
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called the flip element hereinafter, normally contains the
microphone and the ringing element. For good acoustical
performance, the flip element must be held in an optimum
position relative to the body of the radiotelephone. In
S doing so, the microphone is positioned a desired distance
from the user's mouth. Because the microphone and ringing
element must make electrical connection to the
electronics within the body of the radiotelephone, a means
of connection through the hinge area is needed. Such
connection was described in U.S. Patent No. 4,897,873 as
shown in FIG. 1. The microphone and ringing elements
within the flip element portion 101 are connected to
electrical components within the body portion 103 via
wire 10~ which pass through the hinge knuckle 107,
through a slot 109 in t~e shaft 1t1 and then into the body
portion 103. The hinge shaft 11~ is secured to the body
portion 103 such that the hinge knuckle 107 of the flip
element 101 may rotate about the shaft 111. A serious
problem with this design is that the wire 105 gets pinched
between the hinge shaft 111 and an inside surface of the
hinge knuckle 107 as the flip element 101 rotates. The
pinching force eventually breaks the wire causing loss of
electrical contact to either the microphone or the ringing
elements located within the flip element portion 101.
2 5 Other radiotelephones which utilize this type of
design havs all the electronics within the larger of the
two housings. The flip element contains no electronics. A
flip element of this sort may have the capability of
producing an on-hook condition when the flip element is in
the "closed" position and an off-hook condition when the
flip element is rotated to its "opened" position. A
radiotelephone which employs the position of the flip
~lement for control purposes was described in U.S. Patent
No. 4,845,772. When the flip element is in its "closed"
position the radiotelephona is in a standby state ready to
receive an incoming call. The flip element covers at least
a portion of the keypad on the body of the radiotelephone
thereby shielding the keys to avoid accidental key
5 depression or contamination of the keys with foreign
material. When the flip element is in the "openedN
position, some background noise is shielded from the
microphone by the flip element.
A variety of techniquès have been used to position
1 û the flip element in the closed and open position. A
radiotelephone which holds the flip element in the closed
and open position using an enclosed cam element which
follows recesses in one shaft securing the hinge elements
was described in U.S. Patent No. 4,897,873. A detailed
l 5 view of the cam mechanism can be seen in FIGS. 2A and 2B.
FIG. 2A illustrates the position of recesses 201 and 203
when the flip element 101 is in the ciosed, on-hook,
position. FIG. 2B illustrates the position of the recesses
when the flip element is in the open, off-hook, position.
20 When opening the flip element 101, a cam detent 205
moves out of recess 203 in hinge shaft 207 and onto the
full diameter surface of the hinge shaft 207. A spring 209
placed between a wall 211 and the detent cam 205
constantly forces the detent cam 205 against the shaft
25 207. As the flip element continues to rotate to the open or
off-hook condition, the detent cam 205 continues to push
against the shaft 207 and then force itself into the recess
201. The force of the detent cam 205 in the recess 201
holds the flip element portion 101 in the desired position.
30 When the flip element 101 is in both the open and closed
position, the detent cam 205 is projected directly towards
the center of the hinge shaft 207. Since the center of the
hinge shaft 207 is offset from the plane of the flip
element 101 the detent cam 205 must be angularly
.
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positioned. The angular position of the detent cam 205
respective to the plane of the flip element 101 limits the
thickness 215 of the flip element 101. Increased
miniaturization of radiotelephones allow the
S radiotelephones to be packaged in housings of even smaller
dimensions. The hinge assembly described hereinabove are
of dimensions which limits further decrease in the
thickness 215 of the flip element 101 ~
Therefore, a hinge assembly design is required which
l O protects the wire which passes through the hinge knuckle
from the flip element to the body as well as resulting in a
flip element having smaller dimensions.
,
:
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Summary of the Invention
A hinge apparatus for a foldable radiotelephone
apparatus has a body portion and a flip element portion. The
S hinge apparatus is capable of maintaining the flip element
portion in a first position of rotation relative to the body
portion. An essentially cylindrical hinge shaft, having a
circumferential surface and a diametric, rotatably couples
the flip element portion to`the body portion about an axis of
10 rotation through the diametric center. The cylindrical hinge
shaft is prevented from rotating relative ~o the body portion.
A recess is disposed in the circumferential surface. A
follower is disposed at least partially within the flip
element portion and has an end portion disposed in the recess.
15 The follower exerts a force on the cylindrical hinge shaft
along a line of action essentially parallel to the axis of the
follower and at a perpendicular distance between the line of
action and the axis of rotation whereby a torqlJe on the
cylindrical hinge shaft is produced when the flip element
2 0 portion in the first position.
6 207~3
Brief Description of the Drawings
FIG. 1 shows a conventional technique of connecting
the wire from the ringing element and microphone in the
5 flip element to the body.
FIGS. 2A and 2B are cut-away side views of a
conventional cam mechanism where the flip element is
shown in both the closed and open position, respectively.
FIG. 3 is an isometric drawing of a portable
10 radiotelephone which may employ the present invention.
FIG. 4 is a side view of the radiotelephone where the
flip element is nearing the closed positlon.
FIG. 5 is an exploded view of the body portion and the
flip element illustrating the hinge assembly of the
15 radiotelephone shown in FIG. 3.
FIG. 5A is a cut-away view, of the hinge cavity
portion of the body showing a round aperture disposed in an
upstanding rib.
FIG. 5B is an isometric view of the bottom side of
20 the hinge shaft and hinge knuckle shown in FIG. 5.
FIGS. 6A and 6B are cut-away side views of the
detent hinge mechanism where the flip element is shown
in both the closed and open positions, respectively.
FIG. 7 is a more detailed end-view of the hinge shaft
25 illustrated in FIGS. 6A and 6B.
FIG. 8 shows the means of connecting the wires from
the the microphone in the flip element to the body.
FIG. 9 is a cross-sectional view of the hinge portion
of the radiotelephone along the hinge axis.
.
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Brief Description of the Preferred Embodiment
A portable radiotelephone adapted for use in a
radiotelephone system is shown in FIG. 3. This portable
S unit 300 consists basically of two readily apparent
portions, a body portion 301 and a flip element portion
303. The drawing of FIG. 3 shows the flip element in an
"open" position such that a user of the portable unit may
listen via earpiece 305 and may speak into the microphone
10 307. The keypad 309 consists of a plurality of buttons
numbered one through zero, #, and ~, in a familiar
telephone arrangement. The keypad 309 may also have
additional functions buttons such as volume control and
other buttons associated with telephone number recall.
15 An antenna 311 enables wireless communication between
the portable unit and a base station.
When the flip element 303 is open as shown in FIG. 3,
the portable cordless telephone can be in a state of
answering or making a telephone call. Such a state is
20 commonly known as "off-hook". Upon completion of a
telephone call, the user may hang up the portable unit by
moving the flip element into a closed position. This
hanging-up may be accomplished by causing the flip
element 303 to rotate about the axis of the hinge portion
25 312 so that ~he flip element 303 rests against the keypad
309. This action activates a "hook-switch" which causes
the telephone call to be terminated. In the closed position
the portable unit is in a standby state ready to receive an
incoming call. The closing of the flip element 303 can
3 0 best be perceived in FIG. 4. The hook switch in the
preferred embodiment is located within the flip element
303. Activation of the hook switch occurs in the preferred
embodiment when the angle between the body 301 and the
flip element 303 equals approximately 45.
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In the preferred embodiment, the flip element 303 is
held in the open or closed position by a combination of
elements shown in FIG. 5. A detent follower 501 is placed
within a hinge knuckle 503 and forced against the
S cylindrical hinge shaft 505 by a resilient medium such as a
spring 509. The spring 509 is formed from the flat curved
piece of steel having a first end 511 hooked against a
protrusion 513 in the flip e!ement 303. The center portion
of the spring 509 presses against a post 515 such that the
10 second end of the spring 517 forces the detent follower
501 through an aperture 519 into a hinge knuckle 503. The
design of the hinge shaft 505 allows the flip element 303
to be held against the keypad 109 in the on-hook or closed
position and at an obtuse angle (for example, e equals
1 S 150) in the off-hook or open position. One end 521 of the
hinge shaft 505 has an elongated shape which fits into a
slightly larger aperture 523 having essentially the same
shape in a front housing portion 525 of the body 301. Thus,
the rotation of the hinge shaft 505 is stationary with
20 respect to the front housing portion 525 about which the
hinge knuckle 503 may rotate.
A second hinge shaft 527 disposed within a second
hinge knuckle 529 helps support the rotation of the flip
element 303 while providing a means for dressing wires
25 531 attached to a microphone 533 from the flip element
303 to the body. The magnet 801 within the flip element
generates a control signal in the body responsive to the
rotational position of the flip element 303. A cover 535
conceals the spring 509, the microphone 533 and its wires
30 531 and the magnet 801 within the flip element 303.
A clip 550 is placed within the center knuckle 552 to
prevent the shafts 527 and 505 from sliding out of their
respective hinge knuckles 529 and 503
.
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FIG. 5A shows a cross sectional view, of the front
housing portion 525. A round aperture 537 is disposed
through an upstanding rib 539. A cylindrical end portion
541 of the hinge shaft 527 shown in FIG. 5, is disposed
5 within the round aperture 537. Thus, the hinge shaft 527
is allowed to rotate with respect to the front housing
portion 525.
FIG. 5B shows another side of the hinge shaft 527
illustrated in FIG. 5A. The hinge shaft 527 has a three
1 0 sided channel 543 extending a predetermined depth into
the channel 527 along the shaft's entire length. The hinge
knuckle 529 has a three sided guide rail 545 disposed on
the inside surface of the hinge knuckle and extending a
predetermined distance along the knuckle's length. The
1 5 hinge shaft 527 is inserted within the hinge knuckle 529
such that the guide rail 545 is disposed in the channel 543
thereby interlocking the hinge shaft 527 to the hinge
knuckle 529. The hinge shaft 527 is now able to rotate
about its axis with the rotation of the flip element 303.
20 The interlocking feature of the hinge shaft 527 to the
hinge knuckle 529 overcomes the problem encountered in
the prior art (FIG. 1) wherein the wire is pinched as the
hinge knuckle rotates about the shaft.
A more detailed view of the detenting hinge
25 apparatus is illustrated in FIG. 6A and FIG. 6B. FIG. 6A
illustrates the position of recesses 601 and 603, relative
to the detent follower 501, when the flip element 103 is
in the closed, on-hook position. FIG. 6B illustrates the
position of the recesses 601 and 603, relative to the
30 detent follower 501, when the flip element is in the open,
off-hook position. When opening the flip element 303, the
detent follower 501 moves out of recess 601 in the hinge
shaft 505 and onto the full diameter surface of the shaft
505. The spring 509 constantly forces the detent follower
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501 against the hinge shaft 505. As the flip element
continues to rotate to the open or off-hook condition, the
detent follower 501 continues to push against the hinge
shaft 505 and then forces itself into the recess 603. The
force of the detent follower 501 in the recess 603 holds
the flip element 303 in the desired position.
A primary feature of the preferred embodiment of
the present invention is that the detent follower 501
exerts a torque of a force on the hinge shaft 505 about its
center axis when the flip element is in both its closed and
open position. The torque of the force on the hinge shaft
505 is created by angularly disposing recesses 601 and
603 such that the detent follower 501 does not project
through the center of the hinge shaft 505. The advantage
of this design approach allows the detent follower 501 to
be disposed in or near the same plane as the flip element
303 whereby a thinner flip element may be utilized. In the
preferred embodiment, the detent follower 501 is disposed
at an small angle ~ ,for example 10, with respect to the
plane of the flip element 303 to facilitate molding of the
slot 519 in which the detent follower 501 is located.
Alternate embodiments, having different molding
considerations, may afford the opportunity of placing the
detent follower 501 in the same plane as the flip element
303. A thin flip element contributes to the weight
reduction of the portable unit. This primary feature
overcomes the aforementioned prior art conditions
contributing to the greater thickness of the flip element
previously described in FIGS. 2A and 2B.
Now referring to FIG. 7, there is shown a more
detailed view of the end of the hinge shaft 505 shown in
FIGS. 6A and 6B. Recess 601 has two essentially planar
surfaces 701 and 703 in which the planes of the surfaces
intersect to form an angle. The detent follower 501 has
,
1 1 2~782~3
two essentially planar surfaces 705 and 707 which
contact planar surfaces 701 and 703, respectively, in the
recess 601 when the flip element 303 is in the closed, on-
hook position. A primary torque of a force, F1, exerted
S between the planar surface 701 of recess 601 and the
planar surface 705 of the detent follower 501, relative to
the center axis of the hinge shaft 505, preloads the flip
element 303 thereby maintaining the flip element in its
closed position.
lQ Recess 603 also has two essentially planar surfaces
709 and 711. The detent follower 501 has two essentially
planar surfaces 713 and 715 which contact the planar
surfaces 709 and 711, respectively, of recess 603 when
the flip element is in its open, off-hook, position. A
1 S primary torque of a force, F2, is applied between the
planar surface 709 of the recess 603 and the planar
surface 713 of the detent follower 501, relative to the
center axis of the hinge shaft 505, thereby maintaining the
flip element in its open position.
The imaginary planes formed by surface 701 of
recess 601 and surface 711 of recess 603 intersect in an
acute angle, (P, which is related to the angle of the flip
element 303 opening ~3. In the preferred embodiment the
two angles,~Pand~3, sum to approximately 180 when the
flip element 303 is in the open position as shown in FIG.
6B. The design of the hinge shaft 505 allows the flip
element 303 to open or close without further assistance
when it is within 45 of either position. The flip element
also has the ability to over travel the open position by an
amount such as 30, if forced, and return to the open
position automatically when the force is removed.
FIG. 8 shows an end view of the microphone wires
protected within the hinge knuckle. The wires 531 of the
microphone 533 are pulled towards the center of the hinge
8~33
shaft 527 by an arm 805. An advantage of the preferred
embodiment of the present invention is that wires 531
positioned near the center of the hinge shaft 527 undergo
less rotational travel as the flip element is rotated
S thereby minimizing a twisting force placed on the wires.
The hook switch in the preferred embodiment is
located within the flip element 303 and can be seen in FIG.
~. Activation of the hook switch occurs in the preferred
embodiment when the angle between the body 301 and the
flip element 303 equals approximately 45. A conventional
magnet 801 is placed in a position within the flip element
303. A conventional reed switch 803 is placed in a
position within the body 301 essentially opposite the
magnet 801. As the flip element 303 rotates about the
axis of the hinge portion to its closed position, a magnetic
field produced by the magnet 801 closes the contacts
within the reed switch 803 thereby generating a control
signal indicating the on-hook condition. When the flip
element 303 rotates about the hinge portion 312 to its
open position, the magnetic field created by the magnet
801 is removed from the proximity of the reed switch 803
allowing the reed switch contacts to open thereby
generating a control signal indicating the off-hook
condition .
In the preferred embodiment the housing of the body
301 is assembled from two parts shown in FIG. 5 as a rear
housing 551 and a front housing 525. FIG. 9 shows a cross
sectional view of the hinge portion after the elements of
FIG. 5 are assembled. The flip element 303 is connected to
the body by the hinge shafts 505 and 527 mentioned above.
When the rear housing 551 of the body 301 and the front
housing 525 of the body are snapped together, the ribs 901
and 903 of the rear housing 551 nest within the ribs 539
and 524, respectively, in the front housing. Apertures in
1 3 2 ~
the ribs 901 and 903 of the rear housing align themselves
concentrically with corresponding apertures 537 and 523
in the front housing 525. The shafts 527 and 505 push
through the holes in their respective hinge knuckles 529
S and 503, through the holes in the ribs of the front and rear
housings. The clip 550 is then placed within the center
knuckle 552 to prevent the shafts 527 and 505 from
sliding out. In the preferred embodiment the shafts may
only be removed when the` flip element is in the closed
1 0 position.
Therefore, a hinge mechanism for a radiotelephone
has been shown and described. This novel apparatus
results in a thinner flip element advantageously reducing
the weight of the portable unit and dresses the wires from
lS the flip element to the body eliminating broken wires and
minimizing rotational stress.
What is claimed is:
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