Portable apparatus having two rotatable and foldable units and hinge device used for the same

A portable apparatus of the present invention comprises a first unit, a second unit, and a hinge device that is coupled to the first and second units such that the units can be moved to be in contact with or spaced apart from each other and allows relative sliding movement between the first and second units within a certain range. The hinge device exerts a force in a direction in which the first and second units are spaced apart from each other, through the relative sliding movement by a predetermined distance between the two units in the complete contact state of the first and second units.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The disclosure relates to a portable apparatus having two panels movable between open and closed positions.

2. Description of the Related Art

A portable apparatus such as a portable folder-type radiotelephone includes two case units coupled to each other such that they can be moved to folded and unfolded positions of the apparatus with respect to each other, and a hinge device for coupling the two case units to each other. One case unit is provided with a keypad with buttons, and the other case unit is provided with a liquid crystal display. When the portable apparatus is in use, the keypad and the liquid crystal display are moved to the unfolded position of the portable apparatus so that the keypad and display can be exposed to the outside. The hinge device allows the two case units to be coupled to each other and to be smoothly moved to the folded and unfolded positions of the portable apparatus.

A typical portable apparatus is constructed such that when two case units thereof are spaced apart by a predetermined angular distance from each other, they are then automatically moved to an unfolded position of the portable apparatus. An example of a hinge device used for such a portable apparatus includes a hinge device disclosed in Korean Patent No. 266516 (corresponding to U.S. Pat. No. 6,085,387). The hinge device comprises a rotating member, a linearly moving member, a resilient member, and a housing. The housing contains the rotating member, the linearly moving member and the resilient member. The rotating member can rotate about a rotation axis within the housing, and a portion of the rotating member extending along the rotation axis protrudes outside of the housing to form a coupling portion (coupling shaft). The linearly moving member is in contact with the rotating member, and does not rotate within the housing but moves linearly along the rotation axis of the housing. The resilient member applies a force so that the linearly moving member and the rotating member can be brought into close contact with each other within the housing. At this time, contact surfaces of the linearly moving member and the rotating member are properly configured such that the rotating member easily rotates even without an external force in a certain range and is well maintained in a stationary state at a predetermined location.

One of two case units of a portable apparatus that are intended to be coupled to the hinge device constructed as above is fixed to the housing while the other is fixed to the coupling shaft of the rotating member. When the two case units are spaced apart beyond a predetermined angle from each other from a completely folded state of the portable apparatus, the two case units are automatically moved to an unfolded state of the portable apparatus through the operation of the hinge device. Therefore, in order to unfold the portable apparatus, a user should initially apply an external force to the two case units such that they can be moved with respect to each other. However, it is inconvenient for the user to apply the external force with only one hand. This is because the user should insert his/her finger between the two case units where there is no clearance and subsequently move them to be spaced apart from each other. Otherwise, the user should use his/her both hands. Accordingly, there is a need for a portable apparatus with two units, which has a structure for allowing a user to more conveniently cause the two units to be spaced apart from each other to unfold the apparatus.

SUMMARY OF THE INVENTION

One aspect of the invention provides a portable device, which comprises a first panel comprising a first surface; a second panel comprising a second surface; and a connector connecting the first panel and second panel. The connector is configured to rotatably connect the first panel and second panel relative to each other, in which the second panel being rotatable about a panel rotating axis between a first rotational position and a second rotational position. The first and second surfaces face each other and being substantially parallel to each other when the second panel is in first rotational position. The connector is further configured to further slidably connect the first panel and second panel relative to each other, in which the second panel or a portion thereof being substantially linearly movable between a first linear position and a second linear position when the second panel is in the first rotational position. The connector is further configured to actuate rotation of the second panel from the first rotational position toward the second rotational position about the panel rotating axis when the second panel or the portion thereof is in the second linear position.

A further aspect of the invention provides a connector for connecting a first panel and a second panel. Also, the connector can be used as a part of the portable device. In some embodiments, the connector comprises a hinge device, which comprises: a cam, a cam follower and a coupler. The cam has a cam surface, which comprises a first spontaneous moving section. The cam follower is in contact with the cam surface at a contact point. The cam follower is spontaneously rotatable in a first rotational direction about a hinge axis relative to the cam surface when the contact point is located on the first spontaneous moving section. One of the cam and cam follower is substantially non-rotatable relative to the second panel, and the other is rotatable about the hinge axis relative to the second panel as the cam and the cam follower rotates relative to each other. The coupler is connected to the cam or cam follower, in which the coupler rotatable about the hinge axis relative to the second panel as the cam and cam follower rotate relative to each other, the coupler being substantially linearly non-movable relative to the second panel.

The cam surface further comprises a second spontaneous moving section. The cam follower is spontaneously rotatable in a second rotational direction about the hinge axis relative to the cam surface when the contact point is located on the second spontaneous moving section, and the second rotational direction is substantially opposite to the first rotational direction. The cam surface further comprises a peak, which comprises a highest point of the peak and two sloping surfaces next to the highest point of the peak, and the first spontaneous moving section comprises one of the sloping surfaces. The cam surface further comprises a first valley, a first peak and a second valley, and wherein the first spontaneous moving section comprises an area between the first valley and the first peak. When the second panel or the portion thereof is in the second linear position, the contact point is located on the first spontaneous moving section. When the contact point is located on the first spontaneous section, the cam follower begins to rotate about the hinge axis in the first rotational direction relative to the cam surface. When the cam follower rotates about the hinge axis in the first rotational direction relative to the cam surface, the second panel begins to rotate about the panel rotating axis in a rotational direction toward the second rotational position. The coupler is connected to the first panel and is rotatable about the hinge axis relative to the first panel.

The connector comprises a coupler receiver non-movably connected to the first panel. The coupler receiver is configured to receive the coupler while allowing a substantially linear movement of the coupler relative to the first panel from a first coupler position to a second coupler position. The coupler and the coupler receiver are configured such that the substantially linear movement of the coupler relative to the first panel actuates rotation of the coupler about the hinge axis. The coupler comprises a pinion, and the coupler receiver comprises a rack engaged with the pinion. The coupler has a cross-sectional shape taken in a plane substantially perpendicular to the hinge axis, wherein the coupler receiver comprises a guide groove configured to receive and rotate the cross-sectional shape as the cross-sectional shape linearly moves within the guide groove. When the coupler is in the first coupler position, the second panel or the portion thereof is in the first linear position. When the coupler is in the second coupler position, the second panel or the portion is in the second linear position.

The connector further comprises a spring configured to apply a force to the coupler in a direction toward the first coupler position. The connector is further configured to allow rotation of the second panel about a twisting axis relative to the first panel between a first twisting position and a second twisting position. The twisting axis is substantially perpendicular to at least one of the first and second surfaces. When the second panel is in the first twisting position, the second panel or the portion is in the first linear position. When the second panel is in the second twisting position, the second panel or the portion is in the second linear position. The connector further comprises a shaft projecting from one of the first and second panels. The connector further comprises a receiving hole of the tapering rod formed in the other of the first and second panels. The shaft has a distal end and a proximal end, and wherein the proximal end is thicker than the distal end in a cross-section of the shaft taken in a plane substantially parallel to the first surface when the second panel is in the first rotational position. The connector comprises a shaft connected to the first panel and the second panel. The shaft is rotatable about an axis relative to the second panel and linearly movable relative to the second panel between a first shaft position and a second shaft position. The shaft is rotatable about the axis relative to the first panel and substantially linearly non-movable relative to the first panel. The connector further comprises a shaft receiver attached to the second panel. The shaft receiver is configured to receive the shaft while allowing a substantially linear movement of the shaft relative to the second panel from the first position to the second shaft position. The shaft and the shaft receiver are configured such that the substantially linear movement of the shaft relative to the second panel actuates rotation of the shaft about the hinge axis.

In some embodiments, the connector comprises: a housing, a first hinge unit and a second hinge unit. The first hinge unit is substantially enclosed within the housing. The first hinge unit comprises a first coupler rotatable about a first hinge axis relative to the housing. The first coupler is substantially coupled with the first panel. The second hinge unit substantially enclosed within the housing. The second hinge unit comprises a second coupler rotatable about a second hinge axis relative to the housing. The second coupler is substantially coupled with the second panel. The first coupler is rotatable about the first hinge axis relative to the housing through an angle less than about 90°. The angle is less than about 75°. The angle is less than about 50°. At least one of the first and second couplers projects out of the housing. At least one of the first and second couplers is enclosed within the housing and coupled with the corresponding one of the first and second panels within the housing. The second coupler is rotatable about the second hinge axis relative to the housing for an angle from less than 90° to more than 90°. The second coupler is rotatable about the second hinge axis relative to the housing for an angle from about 120° to about 200°.

The first hinge unit comprises: a first cam, a first cam follower and a resilient member. The first cam has a cam surface which comprises a valley. The valley comprises a lowest point of the valley and two sloping surfaces next to the lowest point of the valley. The first cam follower is in contact with the first cam surface and being rotatable relative to the first cam surface about the first hinge axis. The resilient member applies a force to keep the cam follower in contact with the cam surface. The force further rotates the cam follower about the hinge axis relative to the cam surface when the first cam follower contacts one of the two sloping surfaces. The first coupler of the connector is connected to the first cam or the first cam follower and configured to rotate about the first hinge axis when the first cam follower and the first cam surface rotate about the hinge axis relative to each other. The first cam follower contacts the cam surface only within the valley.

The second hinge unit comprises: a second cam, a second cam follower and a resilient member. The second cam has a second cam surface, which comprises a first valley, a first peak and a second valley. The second cam follower is in contact with the second cam surface at a second contact point and rotatable relative to the second cam surface about the second hinge axis. The resilient member applies a force to keep the cam follower in contact with the cam surface. The force further rotates the cam follower about the hinge axis relative to the cam surface when the contact point is located between the first valley and first peak or between the first peak and the second valley. The second coupler of the connector is connected to the second cam or the second cam follower and configured to rotate about the second hinge axis when the second cam follower and the second cam surface rotate about the hinge axis relative to each other. The first rotational position of the second panel is a closed configuration of the device. The second rotational position of the second panel is an open configuration of the device. At least one of the first and second panels comprises an information display screen. At least one of the first and second panels comprises buttons for inputting information.

Another aspect of the invention provides a portable device, comprising: a first panel comprising a first surface; a second panel comprising a second surface; means for rotatably connecting the first panel the and second panel so that the second panel is rotatable about an axis between a first rotational position and a second rotational position, wherein the first and second surfaces face each other and being substantially parallel to each other when the second panel is in the first rotational position; and means for slidably connecting the first panel and the second panel so that the second panel or a portion thereof is substantially linearly movable between a first linear position and a second linear position when the second panel is in the first rotational position. The means for rotatably connecting the first and second panels actuates rotation of the second panel from the first rotational position toward the second rotational position when the second panel or the portion thereof is in the second linear position.

Another aspect of the invention provides a method of operating the portable device. The method comprises: substantially linearly moving the second panel or the portion thereof relative to the first panel from the first linear position to the second linear position when the second panel is in the first rotational position; and actuating rotation of the second panel by the connector from the first rotational position to the second rotational position when the portion of the second panel is in the second linear position.

A further aspect of the invention provides a connector for connecting a first panel having a first surface and a second panel having a second surface. The connector comprises: means for rotatably connecting the first panel and the second panel so that the second panel is rotatable about an axis between a first rotational position and a second rotational position, wherein the first and second surfaces face each other and being substantially parallel to each other when the second panel is in the first rotational position; and means for slidably connecting the first and second panel so that the second panel or a portion thereof is substantially linearly movable between a first linear position and a second linear position when the second panel is in the first rotational position. The means for rotatably connecting the first and second panels actuates rotation of the second panel from the first rotational position toward the second rotational position when the second panel or the portion thereof is in the second linear position.

A further aspect of the invention provides a hinge device, comprising: a housing, a first hinge unit and a second hinge unit, the features of which are described above in connection with other aspect of the invention.

According to an aspect of the present invention, there is provided a hinge device for connecting first and second units to be coupled such that the units can be moved toward and far away from each other, comprising a first rotating member coupled to the first unit to rotate about a first rotation axis; a first contact member coming into contact with the first rotating member; a first resilient member for applying a force to maintain a state where the first rotating member and the first contact member are in contact with each other; a second rotating member coupled to the second unit to rotate about a second rotation axis substantially parallel to the first rotation axis; a second contact member coming into contact with the second rotating member; and a second resilient member for applying a force to maintain a state where the second rotating member and the second contact member are in contact with each other. Here, one of the first rotating member and the first contact member has a first cam portion and the other thereof has a first cam follower portion that comes into contact and cooperates with the first cam portion. One of the second rotating member and the second contact member has a second cam portion and the other thereof has a second cam follower portion that comes into contact and cooperates with the second cam portion. The first cam portion comprises a first slanted surface and a second slanted surface inclined in a direction opposite to that of the first slanted surface, and the first rotating member can be automatically rotated with cooperation of the two slanted surfaces and the first cam follower portion for causing them to be maintained in a contact state. The second cam portion comprises a third slanted surface with which the second cam follower portion comes into contact, and the third slanted surface is inclined in the same direction as the first slanted surface with respect to an identical rotation direction. The first cam follower portion is moved from the first slanted surface to the second slanted surface while the second cam follower portion is moved in a direction ascending along the third slanted surface.

In the hinge device, the first contact member may be linearly moved along the first rotation axis to function as a linearly moving member, and the second contact member may be linearly moved along the second rotation axis to function as a linearly moving member.

In the hinge device, the slope of the second slanted surface of the first cam portion may be gentler than that of the third slanted surface of the second cam portion.

In the hinge device, the second slanted surface of the first cam portion may be provided with a fixing groove into which the first cam follower portion is fitted and secured.

In the hinge device, wall surfaces for preventing the movement of the second cam follower portion may be formed at both sides of the third slanted surface of the second cam portion.

In the hinge device, a valley may be formed at a lowermost end of the third slanted surface of the second cam portion.

The hinge device may further comprise a case for accommodating the first and second rotating members, the first and second contact members, and the first and second resilient members therein.

In the hinge device, the case may have a passage through which a wire for electrically connecting the first and second units to each other.

The hinge device may further comprise a first hinge module with a first housing for accommodating the first rotating member, the first contact member and the first resilient member therein, and a second hinge module with a second housing for accommodating the second rotating member, the second contact member and the second resilient member therein. The first and second hinge modules may be inserted into and coupled to the case.

According to another aspect of the present invention, there is provided a portable apparatus, comprising a first unit with a substantially flat first surface; a second unit with a substantially flat second surface to be in contact with the first surface; and a hinge device coupled to the first and second units such that the first and second units can be moved to cause the first and second surfaces to face each other or to be spaced apart from each other. The hinge device allows relative sliding movement to be established between the first and second units at a certain range in the state where the two units are in contact with each other. The hinge device includes a rotating member connected to one of the first and second units. The rotating member has a range for automatic rotation in a direction in which the first and second units are spaced apart from each other. If the rotating member enters the automatic rotation range due to the relative sliding movement by a predetermined distance between the two units from the complete contact state of the first and second units, the hinge device exerts a force in the direction in which the first and second units are spaced apart from each other.

According to a further aspect of the present invention, there is provided a method of using a portable apparatus including two units movable to be in contact with each other or to be spaced apart from each other, and a hinge device that connects the two units and includes a rotating member coupled to any one of the two units and having a range for automatic rotation in a direction in which the two units are spaced apart from each other, comprising the steps of causing the rotating member to enter the automatic rotation range by slidably moving the two units with respect to each other in a completely folded state of the portable apparatus; and automatically moving the two units to be spaced apart from each other by removing an external force for the sliding movement and by causing the rotating member to be automatically rotated without an external force in the automatic rotation range.

The method may further comprise the step of allowing the two units to be automatically spaced apart from each other and fixing them in a state where the two units are spaced apart from each other at a predetermined angle.

The method may further comprise the step of limiting the relative sliding movement of the two units.

According to a still further aspect of the present invention, there is provided a rotating device for use with a portable apparatus having first and second units relatively rotatable to be in contact with or spaced apart from each other so as to provide rotation between the two units, comprising a track provided in the first unit; a hinge device that includes a rotating member with a coupling shaft movably fitted into the track and is mounted in the second unit; and a first resilient member provided in the first unit for applying a force to move the coupling shaft toward one side in the track. The hinge device includes a contact member coupled to the second unit to cooperate with the rotating member in a contact state therewith, and a second resilient member for applying a force in a direction causing the contact member to be in contact with the rotating member.

In the rotating device, one of the rotating member and the contact member of the hinge device may be provided with a cam follower portion, and the other thereof may be provided with a cam portion that cooperates with the cam follower portion and has a first slanted surface and a second slanted surface inclined in a direction opposite to that of the first slanted surface. As the coupling shaft is moved along the track, the rotating member may be rotated and the cam follower portion may be moved between the first and second slanted surfaces.

In the rotating device, the rotating member of the hinge device may be provided with a pinion, and the first unit may be provided with a rack cooperating with the pinion.

In the rotating device, if the pinion is rotated through the cooperation thereof with the rack such that the coupling shaft is moved within the track in a direction for resisting an elastic force of the first resilient member, the cam follower portion may be moved from one of the slanted surfaces of the cam portion to the other slanted surface.

In the rotating device, the rotating member of the hinge device may have a cylindrical coupling post, and the rotating device may further comprise a pressing member of which one side is in contact with the first resilient member and the other side is in contact with the coupling post.

In the rotating device, the hinge device may further comprise a housing for accommodating the contact member and the second resilient member therein.

In the rotating device, the track may comprise first and second paths connected to each other, and upon movement of the coupling shaft between the first and second paths, the rotating member may be rotated and the cam follower portion may be moved between the first and second slanted surfaces.

In the rotating device, the first and second paths of the track may be provided such that the second path is followed by the first path according to a direction in which the first resilient member pushes the coupling shaft. The second path may extend along a direction in which the first unit is slidably moved with respect to the second unit in the complete contact state of the first and second units. The first path may extend from the second path after being bent in a direction in which the first path is far away from the second unit.

In the rotating device, the coupling shaft may comprise a key plane and a semicircular circumference.

In the rotating device, the second path of the track may extend longer than a diameter of the coupling shaft, and the first path may extend by a radius of the coupling shaft.

In the rotating device, the first unit may further comprise a leaf spring that is in contact with and cooperates with the key plane of the coupling shaft.

In the rotating device, the first unit may be provided with a cylindrical groove at a side opposite to the track, and the second unit may be provided with a truncated conical protrusion to be fitted into the cylindrical groove of the first unit.

According to a still further aspect of the present invention, there is provided a hinge device for use with the rotating device, comprising a rotating member, wherein the rotating member is rotated with an external force until a predetermined angle and without the external force after the predetermined angle, and the rotating member has a coupling shaft with a semicircular cross section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1is a perspective view of a folder-type portable radiotelephone according to a first embodiment of the present invention. Referring toFIG. 1, the portable radiotelephone5comprises a first case unit7provided with a liquid crystal display, and a second case unit9provided with a keypad. The first and second units7and9are rotatably coupled to each other by means of a hinge device10so that they can be moved to folded and unfolded positions of the radiotelephone.

Referring toFIGS. 1 to 4, the hinge device10comprises a case20, first and second rotating members30and40, first and second linearly moving members60and70, first and second resilient members98and99, first and second supporting plates109and120, and a case cover24.

Referring toFIGS. 1 to 4, the case20comprises first and second end walls21and22, and a sidewall23for connecting the first and second end walls21and23to each other. The case cover24closes an opening that is not covered by the sidewall23. First and second through-holes211and212are provided in the first end wall21. Third and fourth through-holes223and224are provided at positions in the second end wall22, which correspond to those of the first and second through-holes211and212formed in the first end wall21. A line for connecting the centers of the facing first and third through-holes211and223becomes a first rotation axis105, and a line for connecting the centers of the facing second and fourth through-holes212and224becomes a second rotation axis110. The first unit7of the portable radiotelephone5rotates about the first rotation axis105with respect to the hinge device10. The second unit9of the portable radiotelephone5slightly rotates about the second rotation axis110with respect to the hinge device10.

The second end wall22is provided with a passage225for causing the two through-holes223and224to communicate with each other. A cable300(seeFIG. 3) for electrically connecting the two units7and9of the portable radiotelephone5passes through the two through-holes223and224in the second end wall22. The cable300is constructed in such a manner that both branches thereof extend from respective ones of the two units7and9of the portable radiotelephone5toward the other units and are bent toward the hinge10to extend into the hinge10and then bent back in the original direction to meet each other. An intermediate portion301that is bent toward and extends into the hinge10is inserted into the hinge through the two through-holes223and224and the passage225to be contained in a second chamber27of the case20to be described later. Although not specifically shown in the figures, the first and second units7and9comprise coupling projections that are rotatably inserted into the two through-holes223and224in the second end wall22of the hinge device10, respectively. Although not specifically shown in the figures, it can be understood by those skilled in the art from the above description that the coupling projections are constructed such that the cable300passes through and is well contained within the coupling projections.

Referring toFIGS. 3 and 4, a supporting wall25is provided in the case20to be parallel with the two end walls21and22at an intermediate position therebetween. The supporting wall25is provided with U-shaped passages251and252at positions at which the first and second rotation axes105and110intersect the supporting wall. The inner space of the case20is partitioned by the supporting wall25into a first chamber26on the side of the first end wall21and the second chamber27on the side of the second end wall22. The first chamber26is divided again into two halves, i.e. a first sub-chamber261through which the first rotation axis105passes and a second sub-chamber262through which the second rotation axis110passes, by means of an upright separation wall29connecting the supporting wall25and the first end wall21. The first sub-chamber261contains the first rotating member30, the first linearly moving member60, the first resilient member98and the first supporting plate109, which will be described later. The second sub-chamber262contains the second rotating member40, the second linearly moving member70, the second resilient member99and the second supporting plate120, which will be described later. The first and second rotating members30and40rotate about the first and second rotation axes105and110, respectively.

The first and second rotating members30and40take the shape of elongated posts extending between the first end wall21and the supporting wall25within the first and second sub-chambers261and262of the case20, respectively. The first and second rotating members30and40comprise base portions32and42, coupling portions34and44, cam follower portions, and extension rods38and48, respectively. Since the first and second rotating members30and40have the same configuration as each other, only the first rotating member30will be described in detail below. The base portion32is in the form of a disk of which one end surface is in contact with the first end wall21of the first sub-chamber261of the case20. The coupling portion34is in the form of a rectangular rod and extends from the base portion32so that it can protrude outside of the case20through a through-hole211in the first end wall21. Although not specifically shown in the figures, the coupling portions34and44of the first and second rotating members30and40are engaged with coupling holes provided in the first unit (designated by reference numeral7inFIG. 1) and the second unit (designated by reference numeral9inFIG. 1) of the portable radiotelephone (designated by reference numeral5inFIG. 1), respectively. The extension rod38extends from the base portion32to the supporting wall25of the case20so that a distal end of the extension rod can be fitted into a passage251. Referring toFIGS. 3,4and5(b), the cam follower portion is provided with two cam follower protrusions361and362placed at an interval of 180 degrees (only one cam follower361shown inFIGS. 3 and 4). The two cam follower protrusions361and362protrude from the base portion32at both sides of the extension rod38in the same direction as the extension rod38.

Through-holes62and72are formed at the centers of the first and second linearly moving members60and70, respectively. The extension rods38and48of the first and second rotating members30and40are fitted into the through-holes62and72. The first and second linearly moving members60and70have cam portions64and74formed at surfaces thereof facing the cam follower protrusions361and362of the first rotating member30and the cam follower protrusions461and462of the second rotating members40, respectively. The cam follower protrusions361and362of the first rotating member30cooperates with the first cam portions64of the first linearly moving member60, while the cam follower protrusions461and462of the second rotating member40cooperates with the second cam portion74of the second linearly moving member70. Deployed cam profiles of the first and second cam portions64and74of the first and second linearly moving members60and70are specifically shown inFIGS. 5(a) and (b), respectively (also shown inFIGS. 6 and 7).

Referring toFIGS. 4 and 5(b), the first cam portion64is symmetric with respect to the first rotation axis105and has identical profiles at an interval of 180 degrees. The first cam portion64of the first linearly moving member60comprises, sequentially along the circumference thereof, a first slanted surface641, a first peak642, a second slanted surface643, a first valley provided with fixing groove644, a third slanted surface645, a second peak646, a fourth slanted surface647, and a second valley provided with fixing groove648. The slopes of the second and fourth slanted surfaces643and647are gentler than those of the first and third slanted surfaces641and645. The two cam follower protrusions361and362of the first rotating member30are fitted into the respective fixing grooves644and648. The fixing grooves644and648are configured such that the cam follower protrusions361and362fitted into the fixing grooves644and648can be moved only toward the relatively gently slanted surfaces643and647. To this end, portions of the fixing grooves644and648contiguous to the relatively steeply slanted surfaces641and645are formed steeply and deeply, while portions of the fixing grooves644and648contiguous to the relatively gently slanted surfaces643and647are formed gently. The degree of steepness thereof can be properly determined according to the shape of the cam follower protrusions361and362.

Referring toFIGS. 4 and 5(c), the second cam portion74of the second linearly moving member70is symmetric with respect to the second rotation axis110and has identical profiles at an interval of 180 degrees. The second cam portion74of the second linearly moving member70comprises a first receiving groove741and a second receiving groove742. The two cam follower protrusions461and462of the second rotating member40are received in the first and second receiving grooves741and742, respectively. The first and second receiving grooves741and742take the same shape. At one side of each of the first and second receiving grooves, a slanted surface7411or7421is formed to extend from a valley7412or7422such that the cam follower protrusions461and462received therein can be slightly moved, and subsequently to be slanted steeply, i.e. more steeply than the second and fourth slanted surfaces643and647of the first cam portion64, thereby limiting the movement of the cam follower protrusions461and462. Therefore, the second rotating member40can be slightly rotated only in one direction. The slanted surfaces7411and7421are formed to be steeper than the second and fourth slanted surfaces643and647of the first cam portion64. This is to stop the cam follower protrusions461and462of the second rotating member40and to allow the movement of only the cam follower protrusions361and362of the first rotating member30upon folding of the portable radiotelephone.

Referring toFIGS. 3 and 4, the first and second resilient members98and99, which are preferably compression coil springs, are fitted around the first and second extension rods38and48of the first and second rotating members30and40, respectively. One side of each of the first and second resilient members98and99is in contact with the first or second linearly moving member60or70and the other side is in contact with the first or second supporting plate109or120to urge the first or second linearly moving member60or70against the cam follower protrusions361and362of the first rotating member30or the cam follower protrusions461and462of the second rotating member40.

The first and second supporting plates109and120take the same shape and are contained in the first and second sub-chambers261and262of the case20to be in contact with the supporting wall25, respectively. The first and second supporting plates110and120are in contact with one ends of the first and second resilient members98and99, respectively. The two supporting plates109and120are provided with passages111and112, respectively, so that the first and second extension rods38and48of the first and second rotating members30and40can pass therethrough.

Now, the operation of this embodiment will be described in detail with reference toFIGS. 5 to 7.FIG. 5(a) is a side view showing a state where the portable radiotelephone ofFIG. 1is completely folded, andFIGS. 5(b) and (c) are views showing the positions of the first and second cam follower protrusions on the cam surfaces of the first and second cam portions in the hinge device when the portable radiotelephone is in the state shown inFIG. 5(a). Referring toFIG. 5(a), the coupling portion34of the first rotating member30of the hinge device10is coupled to the first unit7of the portable radiotelephone5, and the coupling portion44of the second rotating member40of the hinge device10is coupled to the second unit9of the portable radiotelephone5. Referring toFIG. 5(b), the two cam follower protrusions361and362of the first rotating member (designated by reference numeral30inFIGS. 3 and 4) are located on the first and third slanted surfaces641and645of the first cam portion64, respectively. Referring toFIG. 5(c), the two cam follower protrusions461and462of the second rotating member (designated by reference numeral40inFIGS. 3 and 4) are located on the bottoms of the first and second receiving grooves741and742, respectively. As shown inFIG. 3, the first and second resilient members98and99urge the first and second linearly moving members60and70against the cam follower protrusions361and362of the first rotating member30and the cam follower protrusions461and462of the second rotating member40, respectively. Therefore, forces are exerted on the cam follower protrusions361and362of the first rotating member30so that the cam follower protrusions can be moved in a direction descending along the first and third slanted surfaces641and645of the first cam portion64. This direction corresponds to a direction in which the portable radiotelephone5is folded. Further, the cam follower protrusions461and462of the second rotating member40are located and cannot be moved in the first and second receiving grooves741and742of the second cam portion74. Since the portable radiotelephone5has already been in the completely folded state as shown inFIG. 5(a), a force generated by the hinge device10, which intends to fold the portable radiotelephone5, functions to stably maintain the portable radiotelephone5in the folded state.

To unfold the portable radiotelephone5from the state ofFIG. 5, the first unit7is pulled and slid in a direction designated by an arrow away from the portion where the hinge device10is mounted. This state of the portable radiotelephone is shown inFIG. 6(a).FIGS. 6(b) and (c) are views showing the positions of the first and second cam follower protrusions on the first and second cam portions of the hinge device when the portable radiotelephone is in the state shown inFIG. 6(a), respectively. Referring toFIGS. 6(a) to (c), the hinge device10is placed in a state where it is slightly rotated and inclined with respect to the first and second units7and9of the portable radiotelephone5. Due to the rotation, the two cam follower protrusions361and362of the first rotating member30pass over the first and second peaks642and646of the first cam portion64and then enter the second and fourth slanted surfaces643and647, respectively. The two cam follower protrusions461and462of the second rotating member40are slightly moved along the slanted surfaces7411and7421of the first and second receiving grooves741and742of the second cam portion74. If there is no external force in this state, the two cam follower protrusions361and362of the first rotating member30can be automatically moved in a direction descending along the second and fourth slanted surfaces643and647of the first cam portion64. With this movement, the first unit7of the portable radiotelephone5is rotated in the direction in which the portable radiotelephone5is unfolded. Consequently, the two cam follower protrusions361and362are moved along the slanted surfaces643and647and then fitted into and stopped in the first and second fixing grooves644and648of the first cam portion64. At this time, the portable radiotelephone5is in a completely unfolded state. With the urging force of the second resilient member99, the two cam follower protrusions461and462of the second rotating member40are returned to the bottoms of the first and second receiving grooves741and742.FIG. 7(a) is a side view showing a state where the portable radiotelephone ofFIG. 1is completely unfolded, andFIGS. 7(b) and (c) are views showing the positions of the first and second cam follower protrusions on the first and second cam portions of the hinge device when the portable radiotelephone is in the state shown inFIG. 7(a).

When the first unit7is rotated to fold the portable radiotelephone from the completely unfolded state shown inFIG. 7, the two cam follower protrusions361and362of the first rotating member30of the hinge device10come out from the fixing grooves644and648of the first cam portion64and are moved while ascending along the second and fourth slanted surfaces643and647. At this time, the two cam follower protrusions461and462of the second rotating member40are not moved. This is because the slanted surfaces7411and7421formed at the first and second receiving grooves741and742of the second cam portion74are steeper than the second and fourth slanted surfaces643and647of the first cam portion64. When the first unit7of the portable radiotelephone5is further rotated in the direction in which the portable radiotelephone is folded, the two cam follower protrusions361and362of the first rotating member30pass over the first and second peaks642and646of the first cam portion64and then enter the first and second slanted surfaces641and645, respectively. Thereafter, the portable radiotelephone5is automatically folded.

FIGS. 8(a) to (c) are side views showing sequential steps of the process of unfolding a modified portable radiotelephone with the hinge device ofFIG. 2installed therein. Referring toFIGS. 8(a) to (c), the coupling portion34of the first rotating member (designated by reference numeral30inFIGS. 3 and 4) of the hinge device10is coupled to the second unit9of the portable radiotelephone5, and the coupling portion44of the second rotating member (designated by reference numeral40inFIGS. 3 and 4) of the hinge device is coupled to the first unit7of the portable radiotelephone5(the embodiment shown inFIG. 8may be considered as a version in which the positions of the first and second units of the embodiment shown inFIG. 5are interchanged). Referring toFIG. 8(a), the portable radiotelephone5is in the completely folded state. This state of the hinge device10is identical with those shown inFIGS. 5(b) and (c). To unfold the portable radiotelephone5from the completely folded state, the first unit7is pushed and slid in a direction designated by an arrow toward the portion where the hinge device10is mounted. Then, the portable radiotelephone5is in a state shown inFIG. 8(b). At this time, the state of the hinge device10is identical with those shown inFIGS. 6(b) and (c). In this state, the portable radiotelephone5is automatically unfolded to be in the state shown inFIG. 8(c). At this time, the state of the hinge device10is identical with those shown inFIGS. 7(b) and (c).

FIGS. 9 to 11are views showing a hinge device used for the portable radiotelephone ofFIG. 1according to another embodiment of the present invention. Referring toFIGS. 9 to 11, the hinge device10acomprises a case20a, a first hinge module30a, a second hinge module50a, and a cover70a. The case20acomprises an inner wall22a, and sidewalls24aextending in opposite directions along first and second rotation axes105aand110afrom the inner wall22a. First and second spaces21aand23awith the inner wall22ainterposed therebetween are defined within the case20a. Both ends of the case20aare open to define first and second open ends25aand26a. The first open end25abecomes an entrance of the first space21a, and the second open end26abecomes an entrance of the second space23a. First and second mounting holes211aand212ainto which respective housings42aand62aof the first and second hinge modules30aand50a, which will be described later, are fitted are provided in parallel at a position in the first space21ainwardly spaced slightly apart from the first open end25a. The sizes and shapes of the first and second mounting holes211aand212aare determined such that the respective housings42aand62aof the first and second hinge modules30aand50aare tightly fitted thereinto not to rotate with respect to the case20a. A base portion33aof a first rotating member32aof the first hinge module30aand a base portion53aof a second rotating member52aof the second hinge module50, which will be described later, are placed in a space213abetween the first open end25aand entrances of the first and second mounting holes211aand212a. The first open end25ais blocked by the cover70a. The second space23ais provided with first and second connection holes27aand28aformed in parallel along the first and second rotation axes105and110afrom the second open end26atoward the inner wall22a. A connection passage29ais provided between the first and second connection holes27aand28ato connect them to each other. A cable8afor electrically connecting the two units (designated by reference numerals7and9inFIG. 5) of the portable radiotelephone5(designated by reference numeral5inFIG. 5) passes through the two connection holes27aand28aand the connection passage29a, as shown in the figure.

Referring toFIGS. 9 to 11, the first hinge module30acomprises the first rotating member32a, a first linearly moving member36a, a first resilient member40a, the first housing42a, a first coupling rod46a, and a first stopper ring48a. The first housing42acomprises an end wall43a, and sidewalls44aextending along the first rotation axis105afrom the end wall43a. A side of the first housing opposite to the end wall43ais open to form an entrance of the first housing43a. The center of the end wall43ais provided with a through-hole431a. A distal end of the first coupling rod46ato be described later protrudes through the through-hole431aand is then engaged with the first stopper ring48asuch as an E-ring. The sidewalls44aare composed of a plurality of flat walls connected to one another. These flat walls function as keys when inserted and assembled into the first mounting hole211aof the case20a, thereby ensuring rotation together with the first housing42a. Further, as described later, the flat walls also function to cause the first linearly moving member36acontained in the first housing to be rotated together with the first housing.

Referring toFIGS. 9 to 11, the first rotating member32acomprises the base portion33a, a first coupling portion31a, and a first cam follower portion34a. The base portion33atakes the shape of a cylinder with low height (i.e. flat disk) and has the first coupling portion31aand the first cam follower portion34aat both sides thereof. The first coupling portion31atakes the shape of a square post with low height which protrudes from the base portion31aand of which edges are chamfered. The first coupling portion31aprotrudes beyond the cover70afor blocking the first open end25aof the first housing42a. The first cam follower portion34acomprises two cam follower protrusions341aprotruding from the base portion33a. The two cam follower protrusions341atake the same shape and are symmetric with respect to the first rotation axis105a. Each of the two cam follower protrusions341ais tapered with thickness gradually decreasing toward a rounded distal end thereof. The first rotating member32ais provided with a passage hole321apenetrating through the center thereof along the first rotation axis105a. The first coupling rod46apasses through the passage hole321a. Although not specifically shown in the figures, an entrance of the passage hole321aon the side of the first coupling portion31ais countersunk to receive a head461aof the first coupling rod46ato be described later.

Referring toFIG. 11, the first linearly moving member36acomprises sidewalls361a, a first cam portion362aformed on a surface thereof facing the first rotating member32a, and a cylindrical boss363extending from the center of a reverse surface thereof opposite to the first cam portion362a. The first linearly moving member36ais provided with a through-hole364aalong the first rotation axis105a. The first coupling rod46apasses through the through-hole364a. The sidewalls361aare identical with the sidewalls44aof the first housing42ain shape. The first linearly moving member36aconstructed as above is fitted into the first housing42asuch that it cannot rotate but can move linearly along the first rotation axis105a. The first cam portion362ais formed circumferentially around the first rotation axis105a. Since the configuration of the first cam portion362ais the same as the first cam portion64of the embodiment shown inFIG. 4(the detailed configuration is shown inFIG. 5(b)), a detailed description thereof will be omitted. The first cam portion362acooperates with the two cam follower protrusions341aof the first rotating member32a.

Referring toFIG. 11, the first resilient member40aurges the first linearly moving member36aagainst the first rotating member32a. The first resilient member40ais preferably a compression coil spring. The boss363aof the first linearly moving member36ais inserted into one side of the first resilient member40a.

Referring toFIGS. 9 and 11, the first coupling portion46acomprises the head461a, and an elongated cylindrical body462aextending along the first rotation axis105afrom the head461a. A distal end of the body462ais provided with an annular coupling groove463a. The head461ais accommodated in the entrance of the passage hole321aof the first rotating member32aon the side of the first coupling portion31a. The body462asequentially passes through the passage hole321aof the first rotating member32a, the through-hole364aof the first linearly moving member36a, and the interior of the first resilient member40aso that the distal end of the body462aprotrudes outside through the through-hole431aprovided in the end wall43aof the first housing42a. At this time, the coupling groove463aprovided at the distal end of the body462ais also exposed outside of the end wall43aof the first housing42a. The first stopper ring48acalled an “E-ring” is engaged with the coupling groove463ato couple the first coupling rod46ato the first housing42a. The first rotating member32acan rotate about the body462aof the first coupling rod46a.

Referring toFIG. 11, the second hinge module50acomprises the second rotating member52a, a second linearly moving member56a, a second resilient member60a, the second housing62a, a second coupling rod66a, and a second stopper ring68a. The second linearly moving member56ahas a second cam portion562a. The second cam portion562ais formed circumferentially around the second rotation axis110a. Since the configuration of the second cam portion562ais the same as the second cam portion74of the embodiment shown inFIG. 4(the detailed configuration is shown inFIG. 5(c)), a detailed description thereof will be omitted. The second cam portion562acooperates with the two cam follower protrusions541aof the second rotating member52a. Since other structures of the second hinge module50aexcept the second cam portion562aare the same as the first hinge module30a, detailed description thereof will be omitted.

Referring toFIGS. 9 to 11, the cover70ais coupled to the case20ato block the first open end25aof the case20a. The cover70ahas first and second through-holes71aand72athrough which the first and second coupling portions31aand51aof the first and second hinge modules30aand50apenetrate, respectively.

Since the operation of the hinge device shown inFIGS. 9 to 11is the same as the hinge device shown inFIGS. 2 to 8, a detailed description thereof will be omitted. In case of the hinge device shown inFIGS. 9 to 11, the hinge device is assembled by coupling the first and second hinge modules30aand50ain advance and inserting them into the first and second mounting holes211aand212aof the case20athat can be standardized, respectively. Therefore, the assembly of the hinge device is facilitated.

FIGS. 12ato16are views of a portable radiotelephone10baccording to a second embodiment of the present invention. Referring toFIGS. 12a,12band14, the folder-type portable radiotelephone10bcomprises a first case unit12bprovided with a liquid crystal display, a second case unit16bprovided with a keypad, and a hinge device20bfor connecting the first and second case units12band16b. The first case unit12bcomprises a first coupling portion13band a second coupling portion14bprotruding from a reference surface121bon which the keypad is provided. The first and second coupling portions13band14bare located at both sides of one end of the reference surface121bof the first case unit12b. Hereinafter, the end of the reference surface121bwhere the first coupling portion13bis provided is referred to as an “upper end” and an opposite end thereof is referred to as a “lower end.” The first and second coupling portions13band14bare provided with first and second receiving recesses131band141bthat face each other, respectively. The first receiving recess131bextends in a lengthwise direction (up and down direction) of the first case unit12b. The interior of the first receiving recess131bis provided with a first track1311bextending in the lengthwise direction of the first case unit12b. One end of the first track1311b(an end thereof adjacent to the lower end of the first case unit12b) is provided with a protrusion132baround which one end of a first sub resilient member200bto be described later is fitted. A coupling shaft41bof a rotating member40bof the hinge device20bto be described later is fitted into the first track1311bsuch that it can move in the lengthwise direction of the first case unit12b. Further, the first track1311baccommodates a first sub pressing member210band the first sub resilient member200bto be described later, which urge the coupling shaft41bof the hinge device20btoward the upper end of the first case unit12b. One end of the first sub pressing member210bis in contact with the coupling shaft41bof the hinge device20b, and the other end thereof is in contact with one end of the first sub resilient member200b. The end of the first sub pressing member that is in contact with the coupling shaft41bof the hinge device20bis formed with a concavely arcuate depression conforming to the shape of the cylindrical coupling shaft41b. The other end of the first sub pressing member that is in contact with the first sub resilient member200bis provided with a receiving indent211bfor receiving the end of the first sub resilient member200b, and a protrusion212bprovided on the bottom of the receiving indent211bto be fitted into the end of the first sub resilient member200b. The first sub resilient member200bis a compression coil spring. The first receiving recess131bis provided with a rack135bthat is located outside of the first track1311b, extends in the lengthwise direction of the first case unit12band cooperates with a pinion42bof the hinge device20bto be described later. The rack135bis provided adjacent to the reference surface121bto face the same side as viewed by the reference surface121b. The second receiving recess141bis identical with the first receiving recess131bin their structures except that it does not have the rack135b. A coupling post18bof the second case unit16bto be described later is movably fitted into a second track1411bof the second receiving recess141b. The second track1411baccommodates a second sub pressing member310band a second sub resilient member300bto be described later, which urge the coupling post18bof the second case unit16btoward the upper end of the first case unit12b. Since the second sub pressing member310band the second sub resilient member300bare identical with the first sub pressing member210band the first sub resilient member200bin their structures, detailed descriptions thereof will be omitted.

The second case unit16bcomprises a mounting hole17bin which a housing30bof the hinge device20bto be described later is mounted, and the coupling post18bto be fitted into the second track1411bof the first case unit12b. The mounting hole17band the coupling post18bare provided at both sides of an upper end of the second case unit16b. The housing30bof the hinge device20bis mounted in the mounting hole17bnot to rotate with respect thereto. The coupling post18bis in the form of a cylinder and thus can rotate when fitted into the second track1411bof the first case unit12b.

Referring toFIGS. 12aand13, the hinge device20bcomprises the housing30b, the rotating member40b, a linearly moving member50b, a second resilient member80b, a coupling rod90b, and a stopper ring99b. The housing30bcomprises an end wall32b, and sidewalls34bextending along the rotation axis100bfrom the end wall32b. A side of the first housing opposite to the end wall32bis open to form an entrance of the housing30b. The center of the end wall32bis provided with a through-hole321b. A distal end of the coupling rod90bto be described later protrudes through the through-hole321band is then engaged with the stopper ring99bsuch as an E-ring. The sidewalls34bare composed of a plurality of flat walls connected to one another. These flat walls function as keys when inserted and assembled into the mounting hole17bof the second case unit16b, thereby ensuring rotation together with the housing30b. Further, as described later, the flat walls also function to cause the linearly moving member50bcontained in the housing to be rotated together with the housing. It is preferred that the housing30bbe made of metal (e.g., metal such as a brass plate) by means of deep drawing. Otherwise, the housing may be made through injection molding out of a plastic resin material.

Referring toFIGS. 12aand13, the rotating member40bcomprises the pinion42b, a cam follower portion44bprovided at the rear of the pinion42b(hereinafter, a portion of the hinge device20where the opening of the housing30bis formed is defined as a “front portion” and a portion of the hinge device where the end wall32bis formed is defined as a “rear” portion), and the coupling shaft41bprovided in front of the pinion42b. The pinion42bcooperates with the rack135bof the first case unit12b. The coupling shaft41bis in the form of a cylinder and is rotatably fitted into the first track1311bof the first case unit12bof the portable radiotelephone10b. The cam follower portion44bcomprises the first and second cam follower protrusions46band47b. The two cam follower protrusions46band47btake the same shape and are arranged to be symmetric with respect to the rotation axis100b. The two cam follower protrusions46band47bextend in a direction parallel to the rotation axis100btoward a cam surface54bof the linearly moving member50bto be described later. It is preferred that each of the two cam follower protrusions46band47bis tapered with thickness gradually decreasing toward a rounded distal end thereof. The rotating member40bis provided with a passage hole43bpenetrating through the center thereof along the rotation axis100b. The coupling rod90bpasses through the passage hole43b. Although not specifically shown in the figures, an entrance of the passage hole43bon the side of the coupling shaft41bis countersunk to receive a head92bof the coupling rod90bto be described later. The coupling shaft41band the pinion42bof the rotating member40bis located outside of the housing30band the two cam follower protrusions46bare contained in the housing30b. The rotating member40bis rotated about the rotation axis100bwith respect to the housing30bby means of the coupling rod90b.

Referring toFIG. 13, the linearly moving member50bcomprises sidewalls52b, the cam portion54bformed on a surface thereof facing the rotating member40b, and a cylindrical boss56bextending from the center of a reverse surface thereof opposite to the cam portion54b. The linearly moving member50bis provided with a through-hole58balong the rotation axis100b. The coupling rod90bpasses through the through-hole58b. The sidewalls52bare identical with the sidewalls34bof the housing30bin shape. The linearly moving member50bconstructed as above cannot rotate but can move linearly along the rotation axis100bwithin the housing30b. The cam portion54bis formed circumferentially around the rotation axis100b. A profile of the cam portion54bis shown inFIG. 16. Referring toFIG. 16, the cam portion54bhas identical repetitive profiles at an interval of 180 degrees. The cam portion54bsequentially comprises a first slanted surface541b, a first peak542b, a second slanted surface543b, a first valley544b, a third slanted surface545b, a second peak546b, a fourth slanted surface547b, and a second valley548b. The first and second valleys544band548bare provided with insertion grooves5441band5481b, respectively.

Referring back toFIG. 13, the second resilient member80bis a compression coil spring. One side of the second resilient member is contained in the housing30band is in contact with the end wall32bof the housing30b, while the other side thereof is fitted into the boss56bof the linearly moving member50bto urge the linearly moving member50bagainst the rotating member40b.

Now, the operation of this embodiment will be described in detail with reference toFIGS. 15ato15cand16.FIG. 15ashows the portable radiotelephone in the completely folded state and a positional relationship between the hinge device and the rack in this state. Referring toFIG. 15a, the pinion42bof the hinge device20bis located at a distal end of the rack while being urged by the first sub pressing member (designated by reference numeral210binFIG. 14). In this state, the two cam follower protrusions46band47bof the hinge device20bare located on the first and third slanted surfaces541band545bof the cam portion54b, respectively (position P1inFIG. 16). At this time, with the cooperation of the two cam follower protrusions46band47band the cam portion54b, the hinge device20bfunctions to stably maintain the portable radiotelephone10bin the folded state.FIG. 15bshows that the second case unit16bis pulled toward the lower end of the first case unit12bto be linearly moved with respect to the first case unit12bto unfold the portable radiotelephone10bfrom the above state. Referring toFIG. 15b, the pinion42bof the hinge device20bhas been moved through rolling while cooperating with the rack135b. During this process, the two cam follower protrusions46band47bof the hinge device20bpassed over the first and second peaks542band546bof the cam portion54band have just reached certain positions on the second and fourth slanted surfaces543band547b(position P2inFIG. 16). If a user relinquishes his/her hold of the second case unit16bin such a state, the portable radiotelephone10bis automatically unfolded with the cooperation of the two cam follower protrusions46band47band the cam portion54b, and at the same time, the pinion42bof the hinge device20bis moved while being urged by the first sub pressing member (designated by reference numeral210binFIG. 13). Consequently, the portable radiotelephone10bis in the completely unfolded state as shown inFIG. 15c. Referring toFIG. 15c, the two cam follower protrusions46band47bare fitted into the first and second insertion grooves5441band5481bof the cam portion54b, respectively (position P3inFIG. 16), thereby stably maintaining the portable radiotelephone10bin the unfolded state.

FIGS. 17ato19dare views of a portable radiotelephone10caccording to a third embodiment of the present invention. Referring toFIGS. 17ato18, the portable radiotelephone10cis identical with the second embodiment in their structures except that a rack135cis provided at a side far away from a reference surface121cto face the reference surface121c, and first and second sub pressing members210cand310cand first and second sub resilient members200cand300cpush a second case unit16ctoward a lower end of a first case unit12c. Therefore, a detailed description thereof will be omitted.

Now, the operation of the third embodiment will be described in detail with reference toFIGS. 19ato19c.FIG. 19ashows the portable radiotelephone in the completely folded state and a positional relationship between the hinge device and the rack in this state. Referring toFIG. 19a, the pinion42cof the hinge device20cis located at a distal end of the rack while being urged by the first sub pressing member (designated by reference numeral210cinFIG. 18). In this state, the two cam follower protrusions46cand47cof the hinge device20care located on the first and third slanted surfaces541cand545cof the cam portion54c, respectively. At this time, with the cooperation of the two cam follower protrusions46cand47cand the cam portion54c, the hinge device20cfunctions to stably maintain the portable radiotelephone10cin the folded state.FIG. 19bshows that the second case unit16cis pushed toward the upper end of the first case unit12cto be linearly moved with respect to the first case unit12cto unfold the portable radiotelephone10cfrom the above state. Referring toFIG. 19b, the pinion42cof the hinge device20chas been moved through rolling while cooperating with the rack135c. During this process, the two cam follower protrusions46cand47cof the hinge device20cpassed over the first and second peaks542cand546cof the cam portion54cand have just reached certain positions on the second and fourth slanted surfaces543cand547c. If a user relinquishes his/her hold of the second case unit16cin such a state, the portable radiotelephone10cis automatically unfolded with the cooperation of the two cam follower protrusions46cand47cand the cam portion54c, and at the same time, the pinion42cof the hinge device20cis moved while being urged by the first sub pressing member (designated by reference numeral210cinFIG. 18). Consequently, the portable radiotelephone10cis in the completely unfolded state as shown inFIG. 19c. Referring toFIG. 19c, the two cam follower protrusions46cand47care fitted into the first and second insertion grooves5441cand5481cof the cam portion54c, respectively, thereby stably maintaining the portable radiotelephone10cin the unfolded state.

FIGS. 20 to 29are views of a portable radiotelephone5daccording to a fourth embodiment of the present invention. Referring toFIGS. 20 and 21, the portable radiotelephone5dcomprises a first case unit7dprovided with a liquid crystal display, and a second case unit9dprovided with a keypad. The first and second case units7dand9dare rotatably coupled to each other by means of a hinge device10dso that they can be moved to folded and unfolded positions of the portable radiotelephone. Further, as shown inFIG. 20, when the first case unit7dis pushed in a direction designated by a solid arrow, i.e. rightward, with respect to the second case unit9dfrom a state where the portable radiotelephone5dhas been completely folded (the state represented by solid lines), the first case unit7dis linearly moved while being slid in the direction designated by the solid arrow with respect to the second case unit9d.

Referring toFIG. 21, both sides of the first case unit7dare provided with a first track24din the form of a groove into which a coupling shaft14dof the hinge device10dto be described later is movably fitted, and a second track22din the form of a groove into which a cylindrical protrusion18dof the second case unit9dto be described later is movably fitted, respectively. Referring toFIGS. 20,21,23and24, the first track24dis provided with first and second ends241dand242d, and first and second boundaries or interfaces28dand30d, which are located sequentially in the direction of linear movement (designated by the solid arrow inFIG. 20) of the first case unit7din the completely folded state of the portable radiotelephone5d. The second boundary30dof the two boundaries28dand30dis positioned closer to the second case unit9din the completely folded state of the portable radiotelephone5d. A key plane16dand a semicircular circumference17dof the coupling shaft14dof the hinge device10d, which will be described later, are in contact with the first and second boundaries28dand30d, respectively. The first track24dextends from the first end241din the direction of linear movement (sliding direction, or direction designated by the solid arrow inFIG. 20) of the first case unit7din the completely folded state of the portable radiotelephone5dand is then bent. At this time, the first boundary28dis bent far away from the second boundary30dby angle A smaller than 90 degrees at a position just beyond position P and then further extends nearly by the radius of the coupling shaft14dof the hinge device10d. The two ends241dand242dof the first track24dare arc-shaped to conform to the shape of the semicircular circumference17dof the coupling shaft14dof the hinge device10d. Consequently, the boundaries of the first track24dare composed of straight lines and arcs.

Meanwhile, in the completely folded state of the portable radiotelephone5dshown inFIGS. 20 and 21, it is preferred that rotation axis C placed on the diametric key plane16dof the coupling shaft14dbe located at position P that is a bent point on the first boundary28d. The length between the first end241dand position P in the first track24dis determined such that, when the coupling shaft14dof the hinge device10dmoves along the first track24dfrom the completely folded state of the portable radiotelephone5d, the coupling shaft14dcan be rotated to such an extent that the diametric key plane16dof the coupling shaft14dabuts a portion of the first boundary28dbetween the first end241dand position P. It will be understood by those skilled in the art that the length may be lengthened according to results of a survey for use habits or tastes of users of the portable radiotelephone. Accordingly, as described above, it will be understood by those skilled in the art that the first track24dis constructed such that the coupling shaft14dis rotated through a predetermined angle while moving along the first track24d.

Referring toFIG. 21, the second track22dis provided with first and second ends221dand222dlocated sequentially in the direction of linear movement (direction designated by the solid arrow inFIG. 20) of the first case unit7d. The first end221dis provided with a receiving recess2211d. A first resilient member20dis a compression coil spring of which one end is inserted into the receiving recess2211dprovided at the first end221dof the second track22dand the other end is in contact with the cylindrical protrusion18dof the second case unit9d. The first resilient member20dprovides a force for urging the cylindrical protrusion18dof the second unit9dfar away from the first end221dof the second track22d. With this force, the portable radiotelephone5dis stably maintained in the completely folded state that is represented by the solid lines inFIG. 20.

Although not specifically shown in the figures, referring toFIG. 23, the first case unit7dcomprises a leaf spring26d. The leaf spring26dis arranged such that in its initial state, it can maintain the key plane of the coupling shaft in contact with the first boundary28dbetween position P and the second end242din the first track24das shown inFIG. 23. A distal end F of the leaf spring26d, which is on the side of the second end232dof the first track24d, is fixed. It will be understood by those skilled in the art that the leaf spring26dcan be properly positioned to cooperate with the key plane16dof the coupling shaft14dof the hinge device10d.

Referring toFIGS. 20 and 21, the second case unit9dis provided with first and second coupling portions91dand92dthat correspond to the first and second tracks24dand22dof the first case unit7d, respectively. The first coupling portion91dis provided with a mounting hole911dinto which a housing12dof the hinge device10dto be described later is inserted not to rotate. The second coupling portion92dis provided with the cylindrical protrusion18dto be fitted into the second track22dof the first case unit7d. Meanwhile, a circuit line (printed circuit line) can pass between the first and second case units7dand9dthrough the cylindrical protrusion. It will be apparent that this embodiment of the present invention can also be applied to a cosmetic compact that does not require connection by a circuit line. Alternatively, the hinge device may be mounted in the second coupling portion92d, and accordingly, the second track22dof the first case unit7dmay be modified to be identical with the first track24din configuration.

Referring toFIGS. 21 and 22, the hinge device10dcomprises the housing12d, and a rotating member, a linearly moving member and a resilient member, which are received in the case. The rotating member is provided with a cam follower portion and the linearly moving member is provided with a cam. Meanwhile, the rotating member has the coupling shaft14dprotruding outside of the housing12d. The coupling shaft14dprotrudes in the form of a post with a semicircular cross section, along the rotation axis C of the hinge device10d. The coupling shaft14dhas the diametrically extending key plane16dand the semicircular circumference17d. This example of the hinge device may have the same structure as a hinge device disclosed in Korean Patent No. 266516 (corresponding to U.S. Pat. No. 6,085,387) only except the configuration of the coupling shaft (coupling portion). Details disclosed in Korean Patent No. 266516 (corresponding to U.S. Pat. No. 6,085,387) are incorporated herein by reference. However, it will be understood by those skilled in the art that the hinge device of the present invention is not limited thereto but other typical hinge devices may be used. Further, it will be understood by those skilled in the art that the cam member (linearly moving member) with the cam and the cam follower member (rotating member) with the cam follower portion may have other constitutions. The coupling shaft14dis inserted into the first track24dprovided in the first case unit7d.

FIG. 25shows a cam32d, which is provided on the cam member (linearly moving member) of the hinge device10d, in a deployed state, and also shows a cam follower portion34dof the cam follower member (rotating member) at respective moved positions. Referring toFIG. 25, the cam32dcomprises a first slanted surface36d, a peak38d, a second slanted surface40d, and a valley42d. In an initial state (a state where the two case units have been moved to the completely folded state or have been in contact with each other as shown inFIGS. 20 and 21) of the hinge device10d, the cam follower portion34dis located at certain position L1on the first slanted surface36d. When the rotating member (cam follower member) is rotated by an external force, the cam follower portion34dascends along the first slanted surface36dand then reaches highest peak position L2of the cam upon rotation thereof by angle B. When the rotating member (cam follower member) is further rotated (by an external force or automatically) by angle A, the cam follower portion34dremains at position L3on the second slanted surface40d. Thereafter, even though an external force is not exerted thereon, the cam follower portion34ddescends along the second slanted surface40dand reaches position L4of the valley42dby means of a force of the resilient member in the hinge device10d. The cam follower portion34dcan move without an external force until it reaches the valley42d. That is, the coupling shaft34dprovided on the rotating member can rotate without an external force, and thus, the first case unit can rotate with respect to the second unit so that they are spaced apart (or moved far away) from each other.

The operation of the portable radiotelephone will be described below with reference toFIGS. 20 to 26. When the first case unit is pushed in the direction designated by the solid arrow shown inFIG. 20, the first case unit7dis moved as shown inFIG. 26(the moved state is represented by one-dot chain lines inFIG. 20). This corresponds to a state shown inFIGS. 24 and 26, which is obtained by moving the track24din a direction designated by an arrow from an initial state shown inFIG. 23. At this time, the coupling shaft14dis rotated by angle A (larger than angle B) with respect to the housing12dand the second case unit9dwith the housing12dcoupled thereto. Then, the cam follower portion34dis located at position L3shown inFIG. 25. At this time, if a user releases the force with which the first case unit has been pushed, the cam follower portion34ddescends along the second slanted surface40dand reaches position L4of the valley42deven though there is no external force. At this time, the first case unit remains in the rotated state represented by a two-dot chain line inFIG. 20. During this process, the coupling shaft14dreturns to the initial position shown inFIG. 23by means of the restoring force of the resilient member26d.

When the user exerts a force to rotate the first unit7dand thus fold the portable radiotelephone, the cam follower portion34dmoves from position L4via positions L3and L2and is located on the first slanted surface36d, as shown inFIG. 25. At this time, the position of the coupling shaft14dwithin the track24dis maintained in the state shown inFIG. 23. The cam follower portion34dmoves on the first slanted surface36deven though there is no external force, so that the first and second case units7dand9dautomatically move toward each other.

Meanwhile, it will be understood by those skilled in the art that the first and second case units7dand9dcan be conventionally moved far away from each other by rotating the first case unit7dthrough an angle beyond angle B.

FIG. 27shows a modified version in which the position of a leaf spring26efor returning a coupling shaft14eto the initial position is different from that of the leaf spring of the embodiment shown inFIG. 23. Meanwhile, it will be understood by those skilled in the art that the structure for deflecting the coupling shaft to the initial position may be another resilient member such as a compression coil spring or other structures without limiting the structure of the present invention to the leaf spring.

FIGS. 28(a) and (b) show another modified version in which a first case unit7fand a second case unit can be moved far away from each other in the same manner as the previous embodiment by means of cooperation of a coupling shaft14fand a track24feven when the first case unit17fis caused to move in a direction designated by a dotted arrow inFIG. 20. It will be understood by those skilled in the art that such a constitution can be established.

FIGS. 29(a) and (b) show profiles of cams32gand32hin modified versions.

Referring toFIGS. 30 and 31, there is shown a portable radiotelephone10jaccording to a fifth embodiment of the present invention. The portable radiotelephone10jis different from the portable radiotelephone10dofFIG. 20in that a truncated conical protrusion18jis formed at one side of a second case unit9jand a cylindrical groove23jis formed at a first case unit7j. With such structures, as shown inFIG. 31, the first case unit7jcan be slid while rotating with respect to the second case unit9jby pushing the first case unit7jin a lateral direction with respect to a portion with the protrusion18jformed therein while a state where the first and second case units7jand9jare in contact with each other is maintained. It will be understood by those skilled in the art that a hinge device10jinstalled in the second case unit9jcan cooperate with a track24jprovided in the first case unit7jwhen the track24jhas the substantially same structure as the first track24din the embodiment ofFIG. 23.

Although the present invention has been described by way of example as being applied to a portable radiotelephone in the embodiments, it is not limited thereto. It can be understood by those skilled in the art that the present invention can be equivalently applied to other portable apparatuses (e.g., a PDA, a portable computer, a cosmetic case, and the like) each of which has two units that can be moved toward and far away from each other to fold and unfold the apparatus.

All the objects of the present invention described above can be achieved in accordance with the constitution of the present invention. Specifically, a portable radiotelephone can be conveniently used since it can be automatically unfolded by causing one of case units of the portable radiotelephone to linearly move or slidably rotate the case unit with respect to the other case unit with one hand. Further, since first and second hinge modules with first and second rotating members providing two rotation axes are inserted into and coupled to first and second mounting holes of the case unit, a hinge device can be easily assembled, thereby improving productivity thereof.

Although the present invention has been illustrated and described in connection with the preferred embodiments, it can be understood that various modifications, changes and additions can be made thereto without departing from the scope and spirit of the present invention.