Preferential deflection hinged housing configuration

A hinge configuration particularly suitable for use with a radiotelephone includes: an arcuate hinge body having a predetermined body length, a predetermined body thickness and a predetermined radius of curvature; and a pair of arms, a respective one of which is attached to and extends away from a respective end of the arcuate hinge body, the pair of arms each having predetermined arm lengths and predetermined arm thicknesses. The arms are pivotally mounted on a housing such that the arms twist upon pivotal movement of the arcuate hinge body relative to the housing. At least one of the predetermined body length, predetermined body thickness, predetermined radius of curvature, predetermined arm lengths and predetermined arm thicknesses should be selected to induce preferential deflection in the arcuate hinge body relative to the pair of arms upon twisting thereof during pivotal movement of the hinge body so that the arms resist fracture during such repeated pivotal movement.

FIELD OF THE INVENTION 
The present invention relates generally to hinge configurations, and 
relates more particularly to hinge configurations for articles pivoting 
between operative and inoperative positions. 
BACKGROUND OF THE INVENTION 
The portable radiotelephone, also known as a "cellular" telephone, has 
become an increasingly popular item for both personal and commercial use. 
Some users, such as doctors, salespersons, real estate brokers, and the 
like, often find that carrying a telephone on their person or in a motor 
vehicle is quite helpful and convenient, and in some instances almost 
essential, to perform their professional tasks. 
To further increase the convenience afforded by radiotelephones, the trend 
has been for radiotelephone units to be increasingly smaller for easier 
storage and portability. To this end, the "flip" phone was developed. A 
flip phone, an example of which is shown in Design U.S. Pat. No. 304,189 
to Nagele et al., comprises a handset portion and a "flip" portion. The 
handset portion houses push buttons for activating the radiotelephone and 
sending dialing tones, a signal receiving unit and amplifier, and other 
components associated with the operation of the radiotelephone. The flip 
portion, which may house the mouthpiece and associated microphone, is 
hingedly attached to one end of the handset portion. The flip portion 
overlies and contacts a portion of the handset portion when the phone is 
inoperative. To operate the phone, the flip portion is pivoted to an open 
position in which it forms an angle of approximately 135 degrees with the 
handset portion. In this position, the phone is configured so that when 
the speaker is placed adjacent a user's ear, the mouthpiece microphone is 
positioned adjacent a user's mouth; as a result, the flip phone can be 
used in much the same manner as a conventional radiotelephone. The 
popularity of the flip phone is in large part due to the ability of the 
phone to fold very compactly into the closed position when not in use. 
The radiotelephone typically includes structures that lock the flip cover 
into the both the closed and the open positions. It is particularly 
important that the flip cover lock snugly into the closed position; 
otherwise, agitation or other movement of telephone, particularly to a 
position in which the cover faces downwardly, may cause the phone to be 
activated inadvertently. It is also important that the cover lock snugly 
in the operative position for the user's convenience. 
Because the phone relies on pivotal movement of the flip portion for its 
operation, the configuration and, in turn, the operation of the hinge 
interconnecting the flip portion with the handset can greatly influence 
the performance and attractiveness of the phone. The hinge may be 
subjected to significant levels of stress, and in particular to 
fatigue-based stress, due to repeated cycling of the flip portion between 
the operative and closed positions. If the hinge becomes fatigued after 
repeated pivoting cycles, it may loosen to such a degree that it does not 
remain in a desired position; alternatively, the hinge may fracture. Both 
loosening and fracture can lead to inconsistent operation of the phone. 
In addition, it is desirable that, when the cover is in the closed 
position, it be biased toward the closed position. If biasing means are 
present, any slight movement of the phone that could otherwise jostle the 
cover out of the closed position (and thus activate the phone) will not do 
so. Typically biasing is provided by some type of wire spring connected 
with the hinge, see U.S. Pat. No. 4,897,873 to Beutler; U.S. Pat. No. 
5,259,019 to Stilley. However, the inclusion of an additional component, 
such as a wire spring, can add both material and labor costs to the phone. 
Further, it is desirable that the phone be capable of taking a conformation 
in which it can be placed on an underlying surface while in operation to 
enable the user the freedom to do so. Typically in this conformation the 
flip cover pivots to a position approximately 180 degrees from its closed 
position. In this position the operating phone can be placed upside-down 
on an underlying surface to free the user's hands without disconnecting 
the phone. See Design U.S. Pat. No. 282,738 to Nichols for an exemplary 
phone capable of such a configuration. Thus the hinge configuration of a 
radiotelephone should be include the capability of pivoting the cover to a 
fully open position without the operation of the hinge in the closed and 
operative positions being adversely affected. 
SUMMARY OF THE INVENTION 
In view of the foregoing, it is an object of the present invention to 
provide a hinge for a "flip"-style phone which is able to withstand 
repeated opening and closing of the flip portion without fracturing or 
fatiguing to such a degree that operation of the phone is affected. 
It is another object of the present invention to provide a hinge 
configuration suitable for use with a flip-style phone that locks the flip 
cover into a closed position and an operative position. 
It is a further object of the present invention to provide a hinge 
configuration suitable for use with a flip-style phone that biases the 
flip cover to remain in its closed position. 
It is also an object of the present invention to provide a hinge 
configuration suitable for use with a flip-style phone that permits the 
flip cover to pivot to a fully open position that enables the phone to be 
placed upside-down on an underlying surface without disconnecting the 
phone. 
These and other objects are satisfied by the present invention, which 
provides a hinge configuration particularly suitable for a radiotelephone. 
The hinge configuration comprises an arcuate hinge body, such as a flip 
cover, a pair of arms attached to and extending away from a respective end 
of the hinge body, and pivotal mounting means for mounting the hinge body 
on a housing so that each of the arms twists upon pivotal movement of the 
arcuate hinge body relative to the housing. At least one of the body 
width, body thickness, body radius of curvature, arm length, and arm 
thickness is selected to induce preferential deflection of the arcuate 
hinge body relative to the pair of arms upon twisting of the arms during 
pivotal movement of the hinge body. 
This preferential deflection of the hinge body causes the hinge body to act 
as a spring during pivotal movement thereof, which in turn causes the arms 
to resist fracture during repeated pivotal movement. Also, the ability of 
the hinge body to act as a spring can, with proper selection of at least 
one of the dimensions of the hinge body and arms noted above, produce 
sufficient force directed toward the housing by the arms that the hinge 
member resists separation from the housing during repeated pivotal 
movement thereof. 
In a preferred embodiment, the mounting means comprises a pair of pivot 
nubs extending from the arms that are sized and configured to mate with 
and pivot within a pair of pivot recesses located in the housing. The 
hinge further comprises first and second retaining means that retain the 
hinge body in, respectively, a first closed position and a second 
operative position. For a radiotelephone, the flip cover is in the closed 
position as it overlies the handset. In this position, the radiotelephone 
is deactivated. 
Moving the cover to the operative position enables the telephone to be 
activated for operation. In the operative position, the flip cover pivots 
to form an angle of between about 100 and 160 degrees, and more preferably 
between about 120 and 150 degrees, with the housing, which places the 
cover in position to assist in the acoustical transmission of the user's 
voice to the microphone of the radiotelephone. It is also preferred that 
the cover be able to move to a fully open position, in which the cover 
pivots to form an angle of between about 170 and 200 degrees, that allows 
the radiotelephone to be placed with the mouthpiece and earpiece facing an 
underlying surface. This enables the user to set down the phone with the 
mouthpiece and earpiece insulated from sound without deactivating the 
phone.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention now will be described more fully hereinafter with 
reference to the accompanying drawings, in which a preferred embodiment of 
the invention is shown. This invention may, however, be embodied in many 
different forms and should not be construed as limited to the embodiments 
set forth herein; rather, this embodiment is provided so that this 
disclosure will be thorough and complete, and will fully convey the scope 
of the invention to those skilled in this art. 
Referring now to the drawings, a radiotelephone, designated broadly at 10, 
is shown in FIG. 1. The radiotelephone 10 comprises a top handset housing 
40, a bottom handset housing 30 connected thereto to form a cavity 
therein, and a flip cover 20 attached to one end of the top housing 40. 
These parts house electronic components that enable the radiotelephone 10 
to transmit and receive telecommunication signals. A typical arrangement 
of these electronic components is shown schematically in FIG. 2. An 
antenna 13 (also visible in FIG. 1) for receiving telecommunication 
signals is electrically connected to a radio-frequency transceiver 14 that 
is further electrically connected to a controller 15, such as a 
microprocessor. The controller 15 is then electrically connected to a 
speaker 16 that transmits a remote signal from the controller 15 to a user 
of the radiotelephone 10. The controller 15 is also electrically connected 
to a microphone 17 that receives a voice signal from a user and transmits 
it through the controller 15 and transceiver 14 to a remote device. 
Further, the controller 15 is electrically connected to a plurality of 
push buttons 45 and to a display 18 that facilitate phone operation. Those 
skilled in this art will appreciate that radiotelephones having other 
electronic components are also suitable for use with the hinge 
configuration of the present invention, as are other devices, such as tone 
dialers, which benefit from the inclusion of a cover pivotable between 
closed and operative positions. 
In operation, the flip cover 20 pivots relative to the top housing 20 
between a closed position (FIGS. 3 and 5A), an operative position (FIGS. 3 
and 5C), and a fully open position (FIGS. 3 and 5D). In the closed 
position, the flip cover 20 overlies the top housing 40, preferably in 
contacting relationship. In the operative position, the flip cover 20 has 
pivoted about a pivot axis A (FIG. 1) relative to the top housing 40 
between about 100 and 160 degrees, and preferably between about 130 and 
140 degrees, from the closed position. The radiotelephone 10 is typically 
operated in this position; the cover 20 has "flipped" into a position in 
which it assists in the acoustical transmission of the user's voice to the 
microphone 17 as the opposite end of the top housing 40 serves as an 
earpiece for the user. For some embodiments, the radiotelephone 10 
includes operation activation means that are operably coupled with the 
cover 20 such that pivotal movement of the cover 20 toward the operative 
position activates the radiotelephone 10 for use. See U.S. Pat. No. 
5,278,993 to Reiff et al. for an exemplary activation unit. As used 
herein, the term "activate" and derivatives thereof used in connection 
with the operation of the radiotelephone 10 indicate that the 
radiotelephone has been connected with a telephone service and either can 
be or has been further connected with a remote telephonic device, such as 
another telephone, a facsimile machine, or the like. In layman's terms, an 
"activated" telephone is one which receives a "dial tone" from a telephone 
service or which is connected with another telephone line. Thus the term 
"activated" is intended to be synonymous with the art-recognized term 
"off-hook." Conversely, the term "deactivate" and derivatives thereof 
refer to a radiotelephone 10 is not connected with another telephone line 
or with a telephone service transmitting a dial tone; i.e., the term is 
intended to be synonymous with the art-recognized term "on-hook." 
The flip cover 20 (FIGS. 1 and 6) comprises an arcuate hinge body 22, a 
pair of arms 24, 24' and an operation flange 29. The hinge body 22 extends 
between and supports each of the arms 24, 24'. The hinge body 22 is 
preferably slightly arcuate; it bows so that the center portion of its 
inner surface 23 (the surface that faces the top housing 40 when the cover 
20 is in the closed position) is spaced away from the top housing 40 
slightly more than its lateral edge portions (FIG. 4A). The hinge body 22 
should be sufficiently wide that it covers the full width of the top 
housing 40. Typically, this width is between about 100 and 200 millimeters 
and preferably is between about 135 and 150 millimeters. Preferably, the 
radius of curvature of the hinge body 22 is between about 100 and 500 
millimeters, and is more preferably between about 250 and 400 millimeters. 
The thickness of the hinge body 22 is preferably between about 1.0 and 2.0 
millimeters. The thickness, radius of curvature, and width (the dimension 
between the arms 24, 24') of the hinge body 22 should be selected so that 
the hinge body 22 preferentially deflects upon twisting of the arms 24, 
24' (FIG. 4B). As used herein, a structure "preferentially deflects" 
relative to another structure if it deflects significantly in response to 
an induced stress and the second structure does not. By preferentially 
deflecting, the hinge body 22 is able to act as a spring, thereby reducing 
the magnitude of the stress induced in the arms. Also, these same 
dimensions should be selected so that the hinge body 22 does not deflect 
to such a degree that the cover 20 separates from the housing 40 upon 
twisting of the arms 24, 24' due to pivoting of the cover 20. 
Each of the arms 24, 24' (FIG. 6) is attached to and extends from a 
respective end of the hinge body 22. Each of the arms 24, 24' is a mirror 
image of the other arm of the pair about a plane of symmetry P bisecting 
the hinge body 22 equidistant between the arms 24, 24' and normal to the 
pivot axis A. In the interest of clarity and brevity, only the arm 24 will 
be described herein in detail. Those skilled in this art will appreciate 
that the ensuing discussion is equally applicable to the arm 24'. 
In referring to the positions of structures of the arm 24 relative to other 
structures of the radiotelephone 10, the terms "inward," "inwardly," and 
derivatives thereof refer to the direction defined by a vector originating 
at either arm 24, 24' and extending toward the plane of symmetry P. 
Conversely, the terms "outward," "outwardly," "lateral," and derivatives 
thereof refer to the direction opposite the inward direction; i.e., the 
direction defined by a vector originating at the plane of symmetry P and 
extending normal thereto. 
As shown in FIGS. 5A through 5D and 6, the arm 24 has a rounded free end 25 
opposite the end attached to the hinge body 22. The free end 25 includes a 
hemispherical pivot nub 26 and a cylindrical locator post 28, each of 
which is located on and projects inwardly from the inward surface of the 
free end 25. The pivot nub 26 and its corresponding pivot hub on the arm 
24' are coincident with and define the pivot axis A. The pivot nub 26 
should protrude further inwardly than the locator post 28 to encourage the 
cover 20 to remain interconnected with the top housing 40 during pivoting 
of the cover 20; in the illustrated embodiment, the pivot nub 26 protrudes 
between about 1 and 1.5 millimeters from the arm 24, and the locator post 
28 projects between about 0.8 and 1 millimeter from the arm 24. To further 
encourage the pivot nub 26 to remain interconnected with the top housing 
40, it is preferred that the locator post 28 be spaced away from the pivot 
nub 26 as much as is practical and that the locator post 28 be positioned 
near a line extending through the attachment point of the arm 24 to the 
hinge body 22 and the pivot nub 26. Preferably, the arm 24 is between 
about 10 and 20 millimeters in length and between about 1.0 and 3.5 
millimeters in width. 
The top housing 40 includes a face plate 41 and a pair of lateral walls 42, 
42' (FIGS. 1 and 6). The face plate 41 includes a contact surface 43 that 
contacts the cover 20 as it resides in the closed position. The face plate 
41 illustratively and preferably includes a number of apertures 47 that 
receive push buttons 45 that are used to operate the radiotelephone 10. 
The lateral walls 42, 42' are mirror images of one another about the plane 
of symmetry P. For clarity and brevity, only the lateral wall 42 will be 
described in detail herein; those skilled in this art will appreciate that 
the discussion is equally applicable to the lateral wall 42'. 
The lateral wall 42 includes a pivot recess 44, a closed position dimple 
46, and an operative position dimple 48 (FIG. 6). Each of these recesses 
is substantially hemispherical; the pivot recess 44 is preferably between 
about 1.5 and 2.5 millimeters in diameter, and the locator dimples 46, 48 
are between about 1.2 and 1.8 millimeters in diameter. Each of the locator 
dimples 46, 48 are positioned on the lateral wall 42 approximately 
equidistant from the pivot recess 44. The closed position locator dimple 
46 is positioned to receive the locator post 28 when the cover 20 is in 
its closed position. The operative position locator dimple 48 is 
positioned to receive the locator post 28 when the cover 20 is in its 
operative position. Preferably, these dimples 46, 48 are oriented about 
the pivot recess 44 so that line segments extending between (a) the closed 
position locator dimple 46 and the pivot recess 44 and (b) the pivot 
recess 44 and the operative position locator dimple 48 form an angle of 
between about 100 and 160 degrees, and more preferably form an angle of 
between about 130 and 140 degrees. This chosen angle should correspond to 
the angle formed by the faceplate 41 and the cover 20 when the cover 20 is 
in the operative position. 
The cover 20 and the top housing 40 are interconnected so that the pivot 
nubs 26 of the arms 24, 24' are received within the pivot recesses 44 of 
the lateral walls 42, 42' (FIG. 6). When the pivot nubs 26 are so 
received, the cover 20 is free to pivot about the pivot axis A. In its 
closed position, the cover 20 rests against the contact surface 43, and 
locator post 28 is received within the closed position locator dimple 48 
(FIGS. 5A and 8). 
Biasing the cover 20 toward the contact surface 43 of the top housing 40 
when the cover 20 is in its closed position is achieved by the positioning 
of the closed position locator dimple 46 on the lateral wall 42. The 
dimple 46 is positioned on an imaginary circle defined by the pivot recess 
44 (the circle's center) and the dimples 46, 48 (points on the circle's 
circumference). The locator post 28 remains on this circular path as the 
cover 20 moves between its different positions. As the cover 20 moves to 
the closed position, the interaction between the cover 20 and the contact 
surface 43 of the top housing halts the movement of the cover 20, so the 
locator post 28 stops at a point on the imaginary circle. The center of 
the dimple 46 is then positioned at a point on the imaginary circle just 
beyond that reached by the locator post 28 in the closed position. For the 
illustrated embodiment, the center of the closed position locator dimple 
46 is positioned approximately 2.5 degrees on the imaginary circle beyond 
the locator post point. As a result, the locator post 28 is not positioned 
in the center of the dimple 46, but instead is eccentrically positioned 
therein. The interaction between the post 28 and the curvilinear surface 
of the dimple 46 urges the cover 20 toward the contact surface 43 (FIGS. 8 
and 8A). As a result, the cover 20 tends to remain in the closed position 
even if the radiotelephone 10 is inverted so that the cover 20 faces 
downwardly. 
From the closed position, an upwardly directed force on the flange 29 of 
the cover 20 causes the cover 20 to pivot about the pivot axis A as the 
pivot nubs 26 rotate within the pivot recesses 44. Each of the locator 
posts 28 slides from its position within the closed position dimple 46 to 
a position in which the locator post 28 contacts the lateral wall 42 
(FIGS. 5C and 9). Such contact forces the arms 24, 24' to twist, with the 
portions thereof attached to the locator posts 28 being forced away from 
the lateral walls 42. 
While the cover 20 is in an intermediate position, the twisting action of 
the arms 24, 24' induces a bending movement in the hinge body 22. At least 
one of the thickness, radius of curvature, and width of the hinge body 22 
and the thickness and width of the arms 24, 24' is selected so that, under 
such a bending movement and the stress resulting therefrom, the hinge body 
22, rather than the arms 24, 24', preferentially deflects (see FIG. 4B). 
By selecting one or more of the above-noted dimensions so that the hinge 
body 22 preferentially flexes, the fatigue life of the cover 22 can 
increase dramatically. If the hinge body 22 does not preferentially flex, 
repeated cycling of the cover 20 between the closed and intermediate 
positions causes the cover 20 to fracture at the junction between the arms 
24, 24' and the hinge body 22, and to do so after far fewer cycles. 
At least one of the thickness, radius of curvature, and width of the hinge 
body 22 and the width and thickness of the arms 24, 24' should be chosen 
so that, as the cover is in the intermediate position, the pivot nubs 26 
of the arms 24, 24' exert sufficient gripping force on the pivot recesses 
44 to resist separation of the cover 20 from the top housing 40 during 
pivotal movement (FIG. 4B). Because the hinge body 22 preferentially 
deflects relative to the arms 24, 24' and thus acts as a spring, its 
deflection causes the arms 24, 24' to exert a resistive inwardly-directed 
force. This force should be sufficient to prevent the cover 20 from 
separating from the top housing 40 even after repeated pivotal movements. 
The cover 20 can be pivoted into its operative position (FIGS. 5C and 7) by 
continuing to apply a force normal to the flange 29. In the operative 
position, the locator post 28 resides within the operative position dimple 
48 (FIGS. 7 and 7A). The interaction between the locator post 28 and the 
dimple 48 causes the cover 20 to be locked into the operative position. In 
its operative position, the radiotelephone 10 can be activated for 
telephonic communication, and the cover 20 can serve to assist the 
acoustical transmission of the cover's voice to the microphone 17. 
Preferably and illustratively, the cover can also be moved into the fully 
open position shown in FIGS. 3 and 5D. In this position, the 
radiotelephone 10 can be inverted and placed on a horizontal surface. This 
can be desirable if a user wishes to rest the radiotelephone 10 on a flat 
surface in a stable configuration as it is being used without 
disconnecting the telephonic signal (as would occur if the cover 20 was 
moved to the closed position). In the illustrated embodiment, placement of 
the radiotelephone 10 on such a surface can soundproof the microphone 17 
from outside noise, with the result that placing the radiotelephone 10 so 
that the faceplate 41 faces an underlying surface effectively acts to put 
a caller on "hold." In the fully open position, the locator post 28 
contacts the lateral wall 42, the arms 24, 24' twist, and the hinge body 
22 preferentially deflects as in the intermediate position. 
Typically, the cover 20, the top housing 40, and the bottom housing 30 are 
formed of the same material so that the color and gloss of these separate 
components can be matched. Preferably, these components are formed of a 
thermoplastic, with polycarbonate being particularly preferred. Those 
skilled in this art will appreciate, however, that other materials may 
also be suitable for use with this invention. 
Those skilled in this art will appreciate that, although the combination of 
the locator post 28 and the dimples 46, 48 is preferred, any means of 
retaining the cover 20 in the closed and operative positions which induces 
a bending moment in the hinge body 22 during pivotal movement is suitable 
for use with the present invention. For example, the locator post 28 and 
dimples 46, 48 could be switched so that the locator post 28 is positioned 
on the lateral wall 42, 42' and the dimples 46, 48 are located on the arms 
24, 24'. 
The hinge configuration of the present invention enables a flip-style 
radiotelephone to have a cover that moves smoothly between closed, 
operative, and fully open positions, and to do so without fracturing after 
the large number of pivoting cycles typically experienced by such devices. 
Further, the cover exerts sufficient gripping force on the housing that 
repeated pivotal cycles do not cause the cover to separate from the 
housing. 
In the drawings and specification, there have been disclosed typical 
preferred embodiments of the invention and, although specific terms are 
employed, they are used in a generic and descriptive sense only and not 
for purposes of limitation, the scope of the invention being set forth in 
the following claims.