Hinge apparatus for mobile phones

The object of this invention is to provide a hinge apparatus for mobile phones. In the hinge apparatus, a fixed cam is installed in a rotary hinge part, in place of a fixed hinge part, different from conventional hinge apparatuses. Therefore, the design of elements of the hinge apparatus can be preferably changed so as to allow the elements to be easily and simply assembled into a single structure without being scratched. It is thus possible to minimize wobble of the hinge apparatus due to scratches of the elements, and prevent a degradation in the operational performance of the hinge apparatus caused by the wobble.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, in general, to a hinge apparatus for mobile phones and, more particularly, to a hinge apparatus for mobile phones, with a fixed cam installed in a rotary hinge part of the hinge apparatus, in place of a fixed hinge part of the apparatus, different from conventional hinge apparatuses, so that the design of elements of the hinge apparatus can be preferably changed so as to allow the elements to be easily and simply assembled into a single structure without being scratched, thus minimizing wobble of the hinge apparatus due to scratches of the elements and preventing a degradation in the operational performance of the hinge apparatus caused by the wobble.

2. Description of the Prior Art

As well known to those skilled in the art, conventional mobile phones are classified into flip-type phones with a hinged cover covering a variety of buttons of a main body, and folding-type phones with a folding main body. In accordance with the recent trend toward smallness and compactness of mobile phones, the folding-type phones have become more widely used than the flip-type phones.

FIG. 1is a perspective view of a typical folding-type mobile phone. As shown in the drawing, the typical folding-type mobile phone is comprised of a main body1and a fold2. The main body1has a microphone and a variety of buttons, and houses therein a variety of elements used for signal transmission and reception. A rechargeable battery used as a power source of the mobile phone is detachably mounted to the back of the main body1.

The fold2is hinged to the main body1through a hinge apparatus so that the fold2is rotated around the hinge apparatus toward or away from the main body1to be closed or opened.

Such folding-type mobile phones are typically provided with a manual fold rotating mechanism designed to allow a user to manually open or close the fold relative to the main body. Nowadays, some models with a motor-operated fold rotating mechanism capable of automatically opening or closing the fold relative to the main body using a motor as well as allowing a user to manually open or close the fold as desired to enhance the convenience of users and functions of the phones have been proposed and used. Hinge apparatuses10for mobile phones with such motor-operated fold rotating mechanisms are so-called “manual/automatic hinge apparatuses”.

FIG. 2is a sectional view of a conventional manual/automatic hinge apparatus installed in a folding-type mobile phone. As shown in the drawing, the conventional manual/automatic hinge apparatus10designed to allow a user to manually or automatically open or close a fold2relative to a main body1is comprised of a rotary hinge part20integrally provided at the fold2, and two fixed hinge parts30and31integrally provided at the main body1. The rotary hinge part20is hinged at both ends thereof to the two fixed hinge parts30and31.

The rotary hinge part20of the hinge apparatus10has a motor-operated fold rotating mechanism which is set in a housing21and is used for automatically opening or closing the fold2relative to the main body1as desired. The motor-operated fold rotating mechanism is comprised of a power generating unit for generating a rotating drive force, a power transmission unit for selectively engaging with the power generating unit, and an elastic support member for applying an elastic biasing force to the power transmission unit to selectively engage or disengage the power transmission unit with or from the power generating unit in response to an external force applied to the fold by a user.

The power generating unit generates a rotating drive force to rotate the fold2relative to the main body1in either direction, and is comprised of a motor22for generating the rotating drive force, and a reduction gear assembly23for transmitting the rotating drive force of the motor22while lowering the rotating speed.

In a detailed description, the motor22is connected to a signal output unit (not shown) externally provided at a predetermined portion of the main body1, and is turned on by electricity applied from a rechargeable battery attached to the back of the mobile phone in response to a signal outputted from the signal output unit. The motor22thus generates an opposite directional rotating force.

The reduction gear assembly23is assembled with an output shaft of the motor22, and transmits the rotating drive force of the motor22to the power transmission unit while lowering the rotating speed at a predetermined ratio. The reduction gear assembly23is comprised of a plurality of planetary gears (not shown). In the reduction gear assembly23, the planetary gears are assembled to have a predetermined reduction ratio, and function to prevent undesired reverse rotation of the reduction gear assembly23, in addition to lowering the rotating speed.

Therefore, in an automatic operation of the hinge apparatus10, the rotating drive force of the motor22of the power generating unit is transmitted from the output shaft of the motor22to the power transmission unit while the rotating speed is lowered by the planetary gears of the reduction gear assembly23.

The power transmission unit is comprised of a rotary cam24and a fixed cam25. The rotary cam24is housed in the housing21, and is connected to the reduction gear assembly23via a shaft. The rotary cam24is also tapered at an end thereof such that the central portion of the end of the rotary cam24becomes flat and projects toward the fixed cam25, thus forming a tapered projection.

The fixed cam25is received in the second fixed hinge part31while being biased toward the rotary cam24by the elastic support member40. The fixed cam25has a depression tapered at opposite side surfaces thereof. During an automatic fold rotating mode of the hinge apparatus, the rotary and fixed cams24and25come into frictional engagement with each other due to the elastic biasing force of the elastic support member.

The elastic support member40preferably comprises a compression coil spring made of a material having both high elastic strain and high restoring force. The elastic support member40is set in a cavity of the second fixed hinge part31such that a first end of the elastic support member40is stopped by an end wall of the cavity, and a second end is stopped by an end of the fixed cam25.

The elastic biasing force of the elastic support member40is higher than the rotating drive force of the power generating unit. Since the elastic support member40having such a high elastic biasing force biases the power transmission unit in a direction, the rotary and fixed cams24and25of the power transmission unit may engage with or disengage from each other.

The two fixed hinge parts30and31are integrally formed at corners of the hinged end of the main body1. In order to accomplish a hinged connection of one end of the rotary hinge part20to the first fixed hinge part30, a hinge sleeve32is inserted into the first fixed hinge part30. In addition, the fixed cam25is inserted into the second fixed hinge part31while being biased toward the rotary cam24by the elastic support member40, as described above.

When the fold2is assembled with the main body1into a single structure by the hinge apparatus, both ends of the rotary hinge part20are hinged to the two fixed hinge parts30and31, respectively. That is, the housing21of the rotary hinge part20is primarily assembled with the hinge sleeve32of the first fixed hinge part30, so that the first end of the rotary hinge part20is hinged to the first fixed hinge part30.

Thereafter, the second end of the rotary hinge part20is hinged to the second fixed hinge part31. In such a case, the fixed cam25is primarily inserted into the second fixed hinge part31by the use of a fixed cam compressing device (not shown). Due to the fixed cam compressing device, the fixed cam25is maintained in the second fixed hinge part31while compressing the elastic support member40. After the fixed cam25is inserted into the second fixed hinge part31by the use of the fixed cam compressing device, the rotary hinge part20is horizontally aligned with the second fixed hinge part31such that the second end of the rotary hinge part20is fitted over and assembled with the second fixed hinge part31. Thereafter, the fixed cam compressing device is removed from the fixed cam25, so that the fixed cam25is elastically pushed toward the rotary can24by the elastic support member40and the rotary and fixed cams24and25come into frictional engagement with each other. The fold2is thus completely assembled with the main body1into a single structure by the hinge apparatus.

However, the above-mentioned hinge apparatus is problematic as follows. That is, when the rotary hinge part20is horizontally aligned with the second fixed hinge part31such that the second end of the rotary hinge part20is assembled with the second fixed hinge part31, the second end of the rotary hinge part20scratches the interior surface of the second fixed hinge part31. The scratches on the second fixed hinge part31cause wobble of the rotary cam24and the motor of the power generating unit, thus degrading the operational performance of the hinge apparatus due to the wobble.

In addition, it is necessary to compress the fixed cam25by the use of a fixed cam compressing device until the second end of the rotary hinge part20is horizontally aligned with the second fixed hinge part31. Therefore, the second end of the rotary hinge part20often interferes with the second fixed hinge part31during a process of assembling the hinge apparatus, so that it is difficult to assemble the hinge apparatus.

Furthermore, since both the elastic support member40and the fixed cam25are installed in the second fixed hinge part31, it is almost impossible to provide mobile phones having a variety of designs which are accomplished by a change in the design of the second fixed hinge part31. For example, the two fixed hinge parts provided in a hinge apparatus of a mobile phone shown inFIG. 3have a smoothly rounded appearance to be attractive to users, thereby attracting users' attention. However, the second fixed hinge part31of the conventional hinge apparatus must define a large space so as to receive both the elastic support member40and the fixed cam25therein, so that the second fixed hinge part31does not allow mobile phone manufacturers to provide mobile phones having a variety of new designs which are accomplished by a change in the design of the second fixed hinge part31.

Another disadvantage of the conventional hinge apparatus for mobile phones resides in that the elastic biasing force of the elastic support member40is applied to the fixed cam25and to the rotary cam24engaging with the fixed cam25, and the transmitted biasing force is, thereafter, applied to the hinge sleeve32of the first fixed hinge part30through the housing21of the rotary hinge part20, thus enlarging the gap between the rotary hinge part20and the first fixed hinge part30to wider than a predetermined reference gap.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a hinge apparatus for mobile phones, with a fixed cam installed in a rotary hinge part of the hinge apparatus, in place of a fixed hinge part of the apparatus, different from conventional hinge apparatuses, so that the design of elements of the hinge apparatus can be preferably changed so as to allow the elements to be easily and simply assembled into a single structure without being damaged, thus preventing a degradation in the operational performance of the hinge apparatus due to damage to the elements.

Another object of the present invention is to provide a hinge apparatus for mobile phones, in which the rotary hinge part does not interfere with a fixed cam compressing device during a process of assembling the rotary hinge part with a second fixed hinge part, so that it is easy and simple to assemble the hinge apparatus.

A further object of the present invention is to provide a hinge apparatus for mobile phones, which minimizes scratches caused by interference between the elements of the hinge apparatus during the process of assembling the rotary hinge part with the second fixed hinge part.

Still another object of the present invention is to provide a hinge apparatus for mobile phones, which may have a variety of designs due to flexibility in the design of fixed hinge parts.

In order to accomplish the above objects, an embodiment of the present invention provides a hinge apparatus for connecting a fold and a main body of a mobile phone to each other, comprising: a fixed hinge part provided at the main body; and a rotary hinge part provided at the fold and hinged to the fixed hinge part so to be rotated relative to the fixed hinge part, the rotary hinge part comprising: a power generating unit generating a rotating drive force; a rotary cam and a fixed cam selectively performing power transmission of the rotating drive force of the power generating unit; a camshaft assembled with the fixed cam such that the camshaft and the fixed cam are axially movable relative to each other, the camshaft being connected at an end thereof to the fixed hinge part such that an idle rotation of the camshaft relative to the fixed hinge part is prevented; and an elastic biasing member provided in the camshaft to elastically bias the fixed cam and the camshaft in opposite directions.

Another embodiment of the present invention provides a hinge apparatus for connecting a fold and a main body of a mobile phone to each other, comprising: a fixed hinge part provided at the main body; and a rotary hinge part provided at the fold and hinged to the fixed hinge part so to be rotated relative to the fixed hinge part, the rotary hinge part comprising: a power generating unit generating a rotating drive force; a coupling unit receiving the rotating drive force of the power generating unit; a rotary cam assembled with the coupling unit such that the rotary cam and the coupling unit are axially movable relative to each other, but are prevented from idly rotating relative to each other; a fixed cam engaging with or disengaging from the rotary cam, and assembled at an end thereof with the fixed hinge part such that the fixed cam is prevented from idly rotating relative to the fixed hinge part; and an elastic biasing member provided in the coupling unit to elastically bias the rotary cam and the coupling unit in opposite directions.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 4is a sectional view of a hinge apparatus for folding-type mobile phones, according to a first embodiment of the present invention.FIG. 5is a sectional perspective view showing the construction and operation of a fixed cam and a camshaft assembled with each other in the hinge apparatus ofFIG. 4.

As shown in the drawing, the hinge apparatus for folding-type mobile phones according to the present invention is comprised of a rotary hinge part120provided at an end of a fold102of a folding-type mobile phone, and two fixed hinge parts130and131provided at corners of an end of a main body101of the mobile phone. The rotary hinge part120of the fold102is hinged to the two fixed hinge parts130and131of the main body101so as to accomplish a folding structure of the mobile phone.

In a detailed description, the two fixed hinge parts130and131are formed at the corners of the end of the main body101. The lateral thickness of each of the two fixed hinge parts130and131and the interval between the two fixed hinge parts130and131are very important factors which determine the width of the mobile phone. A hinge sleeve132is inserted into the first fixed hinge part130so as to accomplish a hinged connection of one end of the rotary hinge part120to the first fixed hinge part130. The second fixed hinge part131receives a boss shaft126bof a camshaft126in a boss shaft receiving slot133thereof. In such a case, since the boss shaft126-2of the camshaft126has a noncircular cross-section, as will be described later herein, the boss shaft receiving slot133of the second fixed hinge part131has a cross-section corresponding to that of the boss shaft126-2.

The rotary hinge part120is provided at the end of the fold102, and is hinged to the two fixed hinge parts130and131of the main body101so as to be manually or automatically rotated relative to the two fixed hinge parts130and131within a predetermined rotating angle.

The rotary hinge part120of the hinge apparatus has a motor-operated fold rotating mechanism which is set in a housing121and is used for automatically opening or closing the fold102relative to the main body101as desired. The motor-operated fold rotating mechanism is comprised of a power generating unit, a rotary cam124, a fixed cam125, the camshaft126, and an elastic biasing member140. The power generating unit generates a rotating drive force, while the rotary cam124is coupled to the power generating unit to receive the rotating drive force from the power generating unit. The fixed cam125engages or disengages with or from the rotary cam124, so that the two cams124and125selectively cooperate with each other. The camshaft126is comprised of a boss126-1integrated with the boss shaft126-2. The boss126-1is assembled with the fixed cam125such that the boss126-1is axially moved relative to the fixed cam125. The boss shaft126-2is received in the boss shaft receiving slot133formed at the inside end of the second fixed hinge part131, so that a rotation of the fixed cam125is prevented. The rotary cam124, the fixed cam125and the camshaft126constitute a power transmission unit of the fold rotating mechanism. The elastic biasing member140is installed in a cavity of the camshaft126so as to elastically bias the fixed cam125and the camshaft126in opposite directions.

The power generating unit generates the rotating drive force to automatically rotate the fold102relative to the main body101in either direction during an automatic fold rotating mode of the hinge apparatus. The power generating unit is comprised of a motor122for generating the rotating drive force, and a reduction gear assembly123for transmitting the rotating drive force of the motor122while lowering the rotating speed.

In a detailed description, the motor122is electrically connected to a signal output unit (not shown) provided at a predetermined portion of the main body101, and is turned on by electricity applied from a rechargeable battery attached to the back of the mobile phone in response to a signal outputted from the signal output unit. The motor122thus generates an opposite directional rotating force.

The reduction gear assembly123is assembled with an output shaft of the motor122, and transmits the rotating drive force of the motor122to the rotary cam124while lowering the rotating speed at a predetermined ratio. The reduction gear assembly123is comprised of a plurality of planetary gears (not shown). In the reduction gear assembly123, the planetary gears are assembled to have a predetermined reduction ratio, and function to prevent undesired reverse rotation of the reduction gear assembly123, in addition to lowering the rotating speed.

The rotary cam124is connected at a first end thereof to the power generating unit via a shaft so as to receive the rotating drive force from the power generating unit. The rotary cam124is also tapered at a second end thereof such that the central portion of the second end of the rotary cam124becomes flat and projects toward the fixed cam125, thus forming a tapered projection. The rotary cam124thus cooperates with the fixed cam125.

In addition, the fold rotating mechanism preferably has a position sensing unit placed between the reduction gear assembly123of the power generating unit and the rotary cam124. The position sensing unit is comprised of a sensing plate123-1and a sensing brush123-2, and detects an open angle of the fold102relative to the main body101by sensing a rotated angle of the rotary cam124so as to output a stop signal to the motor122of the power generating unit to stop the operation of the motor122when the fold102reaches a predetermined angular position relative to the main body101.

The fixed cam125is arranged such that the fixed cam124engages or disengages with or from the rotary cam124so as to selectively cooperate with the rotary cam124. The fixed cam125is assembled with the camshaft126comprised of the boss126-1integrated with the boss shaft126-2. In such a case, the fixed cam125and the camshaft126are axially movable in opposite directions relative to each other.

In a detailed description with reference toFIG. 5, the fixed cam125has a cylindrical shape, and has a tapered depression at a first end thereof such that the fixed cam125comes into frictional engagement with the rotary cam124. The second end of the fixed cap125has an opening. At least one longitudinal key125-1is axially formed on the external surface of the fixed cam125while extending from the second end of the fixed cam125having the opening to a predetermined position.

The camshaft126comprised of the boss126-1integrated with the boss shaft126-2is fitted over the fixed cam125.

The boss126-1of the camshaft126is a cylindrical body which is longer than the fixed cam125, with a radial pin slot126-3formed at at least one predetermined position of a sidewall of the boss126-1. A key guide groove126-4is axially formed on the internal surface of the boss126-1while axially extending from the pin slot126-3to a predetermined position, so that the key guide groove126-4movably engages with the longitudinal key125-1of the fixed cam125. A pin P is inserted into the pin slot126-3. In such a case, the width of the pin P is larger than that of the pin slot126-3. The pin P inserted in the pin slot126-3thus stops the longitudinal key125-1of the fixed cam125at a predetermined position relative to the key guide groove126-4of the camshaft126. In the present invention, two pin slots126-3are preferably formed at diametrically opposite positions of the sidewall of the boss126-1in an effort to accomplish a stable relative sliding movement of the fixed cam125and the camshaft126.

A stopper126-5is formed on the internal surface of the boss126-1, and limits the axial moving range of the fixed cam124relative to the camshaft126. The stopper126-5thus prevents the elastic biasing member140from being excessively compressed to a level exceeding a predetermined reference level at which the elastic biasing member140is plastically deformed, during the axial relative sliding movement of the fixed cam125and the camshaft126.

The boss shaft126-2extending from an end of the camshaft126has a noncircular cross-section, so that the camshaft126is not rotated relative to the second fixed hinge part131. Therefore, the fixed cam125assembled with the camshaft126is not rotated regardless of a rotation of the rotary cam124. In such a case, the boss shaft126-2having the noncircular cross-section is inserted into the boss shaft receiving slot133of the second fixed hinge part131. Since the boss shaft receiving slot133has a cross-section corresponding to that of the boss shaft126-2, it is possible to prevent the camshaft126from idly rotating relative to the second fixed hinge part131even when the rotary cam124is rotated. In the present invention, the cross-section of the boss shaft126-2may be preferably selected from a triangular cross-section, a rectangular cross-section, a hexagonal cross-section, a semicircular cross-section, and etc.

The elastic biasing member140is installed in the cavity of the camshaft126so as to elastically bias the fixed cam125and the camshaft126in opposite directions. The elastic support member140preferably comprises a compression coil spring made of a material having both high elastic strain and high restoring force. The elastic biasing force of the elastic support member140is higher than the rotating drive force of the power generating unit. Since the elastic support member140having such a high elastic biasing force biases the fixed cam125in the predetermined direction, the rotary and fixed cams124and125may engage with or disengage from each other.

In order to assemble the above-mentioned elements into a desired hinge apparatus, the motor122and the reduction gear assembly123of the power generating unit, the sensing plate123-1and the sensing brush123-2of the position sensing unit, and the rotary cam124, the fixed cam125and the camshaft126of the power transmission unit are sequentially installed in the housing121of the rotary hinge part120. A motor-operated fold rotating mechanism housed in the housing121is thus fabricated. In such a case, the fixed cam125is assembled with the camshaft126as follows. That is, after the elastic biasing member140is installed in the cavity of the camshaft126, the fixed cam125is inserted into the cavity of the camshaft126such that the longitudinal keys125-1of the fixed cam125are aligned and engage with the key guide grooves126-4of the camshaft126.

Thereafter, the housing121of the rotary hinge part120is fitted over the hinge sleeve132of the first fixed hinge part130, so that the first end of the rotary hinge part120is hinged to the first fixed hinge part130. In addition, the second end of the rotary hinge part120is hinged to the second fixed hinge part131. In order to hinge the second end of the rotary hinge part120to the second fixed hinge part131, the boss shaft126-2of the camshaft126is primarily pushed by the use of the fixed cam compressing device (not shown) in a direction where the elastic biasing member140is compressed. The camshaft126is thus axially moved inward relative to the fixed cam125until the boss shaft126-2is completely retracted into the housing121. In such a case, the sliding axial movement of the camshaft126relative to the fixed cam125is limited within a predetermined range by the stopper126-5formed on the internal surface of the boss126-1, so that it is possible to prevent the elastic biasing member140from being excessively compressed to a level exceeding the predetermined reference level at which the elastic biasing member140is plastically deformed. The rotary hinge part120with the retracted camshaft126is, thereafter, positioned such that the second end of the rotary hinge part120comes into contact with the inside end of the second fixed hinge part131. The second end of the rotary hinge part120in the above state is pushed downward until the rotary cam124is horizontally aligned with the second fixed hinge part131. At that time, the retracted boss shaft126-2of the camshaft126is elastically projected from the housing121by the restoring force of the compressed elastic biasing member140and is inserted into the boss shaft receiving slot133of the second fixed hinge part131. The second end of the rotary hinge part120is thus completely hinged to the second fixed hinge part131.

That is, after the second end of the rotary hinge part120is allowed to lean on the inside end of the second fixed hinge part131, the second end of the rotary hinge part120is slowly pushed downward. The second end of the rotary hinge part120thus moves downward along the end surface of the second fixed hinge part131while the camshaft126compresses the elastic biasing member140. At a time the rotary hinge part120is horizontally aligned with the second fixed hinge part131during the downward movement, the retracted boss shaft126-2of the camshaft126is elastically projected from the housing121, and is inserted into the boss shaft receiving slot133of the second fixed hinge part131.

Therefore, different from conventional hinge apparatuses in which a fixed cam must be continuously compressed by the use of a fixed cam compressing device until the second end of a rotary hinge part is horizontally aligned with a second fixed hinge part during a process of assembling a hinge apparatus, the hinge apparatus of the present invention is advantageous in that it is not necessary to compress the camshaft by the use of the fixed cam compressing device after placing the second end of the rotary hinge part against the inside end of the second fixed hinge part. Therefore, the elements of the hinge apparatus according to the present invention are easily and simply assembled into a single structure, and, furthermore, the rotary hinge part does not interfere with the fixed cam compressing device during the hinge apparatus assembling process, so that the assembling process is further simply and easily accomplished.

The hinge apparatus according to the first embodiment of the present invention allows a reduction in the lateral thickness of the second fixed hinge part to a desired level, so that it is possible to produce small-sized mobile phones. That is, the second fixed hinge part of the inventive hinge apparatus effectively accomplishes its hinge support function by the boss shaft receiving slot, so that the lateral thickness of the second fixed hinge part may be remarkably reduced by minimizing the size of the remaining part except for the boss shaft receiving slot. Alternatively, the lateral thickness of the second fixed hinge part according to the present invention may remain the same as that of a conventional hinge apparatus, however, in such a case, the design of the fixed hinge parts may be preferably changed, as shown inFIG. 3. It is thus possible to produce mobile phones having a variety of new designs accomplished by a change in the design of the fixed hinge parts. In a brief description, the hinge apparatus of the present invention allows production of mobile phones having many designs changeable due to design flexibility of the fixed hinge parts.

The hinge apparatus according to the first embodiment of the present invention allows a user to automatically or manually open or close the fold relative to the main body.

When the user manually opens or closes the fold102relative to the main body101, the user rotates the fold102in a desired direction relative to the main body101. In such a case, the rotary hinge part120of the fold102is rotated in the same direction as the rotation of the fold102, so that the rotary cam124is rotated. The rotary and fixed cams124and125thus slip off, and the fixed cam125in such a state axially moves in the camshaft126while compressing the elastic biasing member140, so that the fixed cam125disengages from the rotary cam124with a space defined between the two cams124and125. Therefore, the rotary hinge part120is smoothly rotated, and the fold102is smoothly opened or closed.

When the user wants to automatically open the fold102, the user manipulates the signal output unit of the main body101, so that an electric signal is outputted to the power generating unit. In response to the electric signal, the motor122is turned on by electricity applied from the battery of the mobile phone, and is rotated in a direction to generate a desired directional rotating force. The rotating force of the motor122is transmitted to the rotary and fixed cams124and125while being lowered in the rotating speed by the reduction gear assembly123. In such a case, the elastic biasing force of the elastic support member140is higher than the rotating drive force of the motor122, so that the engagement of the rotary and fixed cams124and125is maintained. In addition, the boss shaft126-2of the camshaft126has a noncircular cross-section, and the boss shaft receiving slot133of the second fixed hinge part131receiving the boss shaft126-2has a cross-section corresponding to that of the boss shaft126-2. Therefore, an idle rotation of the camshaft126relative to the second fixed hinge part131is prevented, and the fixed cam125assembled with the camshaft126is not rotated. The rotary hinge part120which fixedly houses the motor122is rotated by the rotating drive force of the motor122, so that the fold102is automatically opened or closed.

The hinge apparatus according to the first embodiment of the present invention is advantageous in that the elements of the hinge apparatus are easily and simply assembled, and the fixed cam125is installed in the rotary hinge part120, in place of the second fixed hinge part131, different from conventional hinge apparatuses, and the camshaft126is axially moved relative to the fixed cam125, so that the lateral thickness of the second fixed hinge part131may be desirably reduced or the design of the fixed hinge parts can be preferably changed.

FIG. 6is a sectional view of a hinge apparatus for folding-type mobile phones, according to a modification of the first embodiment of the present invention. As shown in the drawing, the general shape of the hinge apparatus according to the modification remains the same as the first embodiment, but the rotary cam124, the fixed cam125and the camshaft126are set in a casing to form a module. That is, the rotary cam124, the fixed cam125and the camshaft126are housed in the casing C of the module, so that the relative operation of the rotary cam124, the fixed cam125and the camshaft126is performed inside the casing C. Therefore, even when the second end of the rotary hinge part120scratches the inside end surface of the second fixed hinge part131during the process of assembling the elements of the hinge apparatus, wobble of the elements due to scratches on the end surface of the second fixed hinge part131is preferably intercepted by the casing C. Therefore, it is possible to prevent degradation in the operational performance of the hinge apparatus and a formation of an undesired gap between the rotary hinge part120and the fixed hinge parts130and131caused by the wobble.

In the hinge apparatus according to the modification of the first embodiment, the pin P used for limiting an axial sliding movement of the fixed cam125may be removed, since the axial sliding movement of the fixed cam125can be limited by the casing C.

FIGS. 7 and 8are views of a hinge apparatus for folding-type mobile phones, according to a second embodiment of the present invention. As shown in the drawings, the general shape of the hinge apparatus according to the second embodiment remains the same as the first embodiment, but the boss126-1and the boss shaft126-2of the camshaft126are separated from each other, different from the integrated camshaft126of the first embodiment. The boss shaft126-2is inserted in a shaft hole H formed at an end of the boss126-1. The boss shaft126-2has a noncircular cross-section, for example, a semicircular cross-section, and the shaft hole H of the boss126-1has a cross-section corresponding to that of the boss shaft126-2. Therefore, an idle rotation of the boss126-1relative to the boss shaft126-2coupled to the second fixed hinge part131is prevented.

The hinge apparatus according to the second embodiment is advantageous in that both ends of the rotary hinge part120are hinged to the two fixed hinge part130and131while pushing only the boss shaft126-2during a process of assembling the elements into the hinge apparatus, so that it is easy to assemble the hinge apparatus.

FIG. 9is a sectional view of a hinge apparatus for folding-type mobile phones, according to a modification of the second embodiment of the present invention. As shown in the drawing, the general shape of the hinge apparatus according to the modification remains the same as the second embodiment, but the rotary cam124, the fixed cam125, the boss126-1, and the boss shaft126-2are set in a casing C to form a module. Therefore, the relative operation of the rotary cam124, the fixed cam125and the camshaft126is performed inside the casing C. Therefore, even when the second end of the rotary hinge part120scratches the inside end surface of the second fixed hinge part131during a process of assembling the elements of the hinge apparatus, wobble of the elements due to scratches on the end surface of the second fixed hinge part131is preferably intercepted by the casing C. It is thus possible to prevent degradation in the operational performance of the hinge apparatus and a formation of an undesired gap between the rotary hinge part120and the fixed hinge parts130and131caused by the wobble.

In the hinge apparatus according to the modification of the second embodiment, the pin P used for limiting an axial sliding movement of the fixed cam125may be removed, since the axial sliding movement of the fixed cam125can be limited by the casing C.

FIG. 10is a sectional view of a hinge apparatus for folding-type mobile phones, according to a third embodiment of the present invention. As shown in the drawing, the hinge apparatus for folding-type mobile phones according to the third embodiment is comprised of two fixed hinge parts130and131provided at corners of an end of a main body101of a mobile phone, and a rotary hinge part120provided at an end of a fold102and hinged to the two fixed hinge parts130and131so as to accomplish a folding structure of the mobile phone. The rotary hinge part120is comprised of a power generating unit, a coupling unit150, a rotary cam160, a fixed cam161, and an elastic biasing member140. The power generating unit generates a rotating drive force, while the coupling unit150receives the rotating drive force from the power generating unit. The rotary cam160is assembled with the coupling unit150such that the rotary cam160is axially moved relative to the coupling unit150, but is prevented from idly rotating relative to the coupling unit150. The fixed cam161engages or disengages with or from the rotary cam160, so that the two cams160and161selectively cooperate with each other. The fixed cam161is assembled with the second fixed hinge part131such that the fixed cam161is prevented from idly rotating relative to the second fixed hinge part131. The elastic biasing member140is installed in a cavity of the coupling unit150so as to elastically bias the rotary cam161and the coupling unit150in opposite directions.

In a detailed description with reference toFIG. 10, the power generating unit of the hinge apparatus according to the third embodiment of the present invention is comprised of a motor122for generating the rotating drive force, and a reduction gear assembly123for transmitting the rotating drive force of the motor122while lowering the rotating speed, in the same manner as that described for the above-mentioned embodiments.

The power generating unit is assembled with the coupling unit150which receives the rotating drive force from the power generating unit, and transmits the rotating drive force. The coupling unit150is comprised of a coupler151and a boss152. The coupler151receives the rotating drive force from the power generating unit. The boss152is assembled with the rotary cam160inside the coupling unit150such that the rotary cam160is axially moved relative to the boss152, but is prevented from idly rotating relative to the boss152, so that the boss152transmits the rotating drive force to the rotary cam160. The coupler151and the boss152may be integrally formed as a single structure, or may be separately formed prior to being bonded or welded to each other into a single structure.

In the coupling unit150, the rotary cam160is assembled with the boss152such that the rotary cam160is axially moved relative to the boss152, but is prevented from idly rotating relative to the boss152. In order to accomplish the above-mentioned engagement of the rotary cam160with the boss152, at least one longitudinal key152-1is axially formed on the internal surface of the boss152, while at least one key guide groove160-1is axially formed on the external surface of the rotary cam160, so that the key guide groove160-1movably engages with the longitudinal key152-1, as shown inFIG. 11. Of course, it should be understood that the key guide groove may be formed on the internal surface of the boss152, while the key may be formed on the external surface of the rotary cam160, without affecting the functioning of the present invention.

The fixed cam161is installed in the hinge apparatus such that it engages or disengages with or from the rotary cam160. The outside end of the fixed cam161passes through a hole of the boss152, and is assembled with the second fixed hinge part131such that the fixed cam161is prevented from idly rotating relative to the second fixed hinge part131.

The rotary cam160preferably has a cavity along a central axis thereof, while the fixed cam161preferably has a shaft161-1which is inserted into the cavity of the rotary cam160. The shaft161-1acts as a rotating axis of the rotary cam160, so that an eccentric rotation of the rotary cam160is prevented. The shaft161-1also prevents a plastic deformation of the elastic biasing member140. That is, the inside end of the shaft161-1is stopped by the coupler151during an axial sliding movement of the fixed cam161when the elements are assembled into a hinge apparatus, so that the axial sliding movement of the fixed cam161is limited. Therefore, the shaft161-1prevents the elastic biasing member140from being excessively compressed to a level exceeding a predetermined reference level at which the elastic biasing member140is plastically deformed.

In the same manner as that described for the first embodiment, the hinge apparatus according to the third embodiment allows a user to automatically or manually open or close the fold relative to the main body.

When the user manually opens or closes the fold102relative to the main body101, the user rotates the fold102in a desired direction relative to the main body101. In such a case, the rotary hinge part120of the fold102is rotated in the same direction as the rotation of the fold102, so that the coupling unit150is rotated. Since the rotary cam160is assembled with the coupling unit150such that an idle rotation of the rotary cam160relative to the coupling unit150is prevented, rotary cam124is rotated by the rotation of the coupling unit150. Due to the rotation of the rotary cam160, the rotary and fixed cams160and161slip off. In such a case, since the rotary cam160is axially movable relative to the coupling unit150, the rotary cam160moves away from the fixed cam161in a direction at which the rotary cam160compresses the elastic biasing member140. That is, the rotary cam160disengages from the fixed cam161, and the rotary hinge part120is smoothly rotated. The fold102is thus smoothly opened or closed.

When the user wants to automatically open the fold102, the user manipulates the signal output unit, so that an electric signal is outputted to the power generating unit. In response to the electric signal, the motor122is turned on by electricity applied from a battery of the mobile phone, and is rotated in a direction to generate a desired directional rotating force. The rotating force of the motor122is transmitted to the coupling unit150while being lowered in the rotating speed by the reduction gear assembly123. In such a case, the elastic biasing force of the elastic support member140which biases the coupler151is higher than the rotating drive force of the motor122, so that the coupling unit150is maintained at a stop position thereof. Therefore, the rotary hinge part120which fixedly houses the motor122is rotated by the rotating drive force of the motor122, so that the fold102is automatically opened or closed.

The hinge apparatus according to the third embodiment is advantageous in that the elements of the hinge apparatus are easily and simply assembled. In order to assemble the above-mentioned elements into a desired hinge apparatus, the motor122and the reduction gear assembly123of the power generating unit, the coupling unit150, the elastic biasing member140, the rotary cam160, and the fixed cam161are sequentially installed in the housing121of the rotary hinge part120. The rotary hinge part120housed in the housing121is thus fabricated.

Thereafter, the housing121of the rotary hinge part120is fitted over the hinge sleeve132of the first fixed hinge part130, so that the first end of the rotary hinge part120is hinged to the first fixed hinge part130. In addition, the second end of the rotary hinge part120is hinged to the second fixed hinge part131. In order to hinge the second end of the rotary hinge part120to the second fixed hinge part131, the projected end of the fixed cam161is primarily pushed by the use of a fixed cam compressing device (not shown) in a direction where the fixed cam161pushes the rotary cam160. The rotary cam160thus axially moves relative to the boss152of the coupling unit150while compressing the elastic biasing member140. In such a case, the shaft161-1of the fixed cam161limits the axial movement of the rotary cam160, so that it is possible to prevent the elastic biasing member140from being excessively compressed to a level exceeding the predetermined reference level at which the elastic biasing member140is plastically deformed.

The rotary hinge part120with the retracted fixed cam161is, thereafter, placed against the inside end of the second fixed hinge part131, and is pushed downward until the fixed cam161is horizontally aligned with the second fixed hinge part131. At that time, the retracted fixed cam161is elastically projected from the housing121by the restoring force of the compressed elastic biasing member140, and is inserted into the boss shaft receiving slot133of the second fixed hinge part131. The second end of the rotary hinge part120is thus completely hinged to the second fixed hinge part131.

Therefore, the hinge apparatus according to the third embodiment is advantageous in that it is easy to assemble the elements into a desired hinge apparatus. In addition, the lateral thickness of the fixed hinge parts may be remarkably reduced to a desired level, or the design of the fixed hinge parts may be preferably changed.

FIG. 12is a sectional view of a hinge apparatus for folding-type mobile phones, according to a modification of the third embodiment of the present invention. The general shape of the hinge apparatus according to the modification of the third embodiment remains the same as that of the third embodiment ofFIG. 10, but the shapes of the rotary cam and the fixed cam are changed to be opposed to those of the third embodiment. The operational effect of the hinge apparatus according to this modification is similar to that of the third embodiment, and further explanation is thus not deemed necessary.

As described above, the present invention provides a hinge apparatus for mobile phones, which is easily and simply assembled. The elements of the hinge apparatus do not interfere with each other during a process of assembling the hinge apparatus. Another advantage of the inventive hinge apparatus resides in that the lateral thickness of the fixed hinge parts may be remarkably reduced to a desired level to accomplish a desired reduction in the size of mobile phones, or the design of the fixed hinge parts may be preferably changed.