Hinge assembly and electronic device using the same

A hinge assembly includes a first pivot shaft, a second pivot shaft, a third pivot shaft, a first bracket, a second bracket, a first meshing wheel, a second meshing wheel, a third meshing wheel, and a transmission belt member sleeved on both the first meshing wheel and the third meshing wheel. The first pivot shaft, the second pivot shaft, and the third pivot shaft are substantially parallel. The first and second brackets are non-rotatably sleeved on the first and second pivot shafts, respectively. The third meshing wheel is disposed between the first meshing wheel and the second meshing wheel, and meshes with the second meshing wheel and the transmission belt member. An electronic device using the hinge assembly is also provided.

BACKGROUND

1. Technical Field

The present disclosure generally relates to hinges, and more particularly to a hinge assembly applied in an electronic device.

2. Description of Related Art

Many electronic devices include hinged elements. To ensure that one part is capable of rotating relative to the other, a hinge assembly applied in an electronic device often includes a first bracket, a second bracket, four pivot shafts, two main gears, and two transmission gears. Two of the pivot shafts are received in the first bracket and the second bracket respectively and the main gears are non-rotatably sleeved on these pivot shafts, respectively. The transmission gears are positioned between the main gears and sleeved on the other two pivot shafts. One transmission gear meshes with the other transmission gear and one main gear simultaneously.

In use, the first bracket is rotated, and it rotates one of the main gears correspondingly. Thereby, the second bracket is rotated by the other main gear simultaneously with the main gear. Since the meshing gears rotate in reverse directions, when the main gears and the transmission gears rotate, the first bracket and the second bracket rotate in opposite directions. Thereby, two hinged elements of an electronic device using the hinge assembly may be opened or closed at double-speed.

However, since each of the two transmission gears meshes with one main gear and one transmission gear simultaneously, and each of the transmission gears and the main gears are sleeved on one pivot shaft, the transmission gears and the main gears must be assembled to mesh accurately to avoid choking of the gears.

Therefore, there is room for improvement within the art.

DETAILED DESCRIPTION

The present hinge assembly may be applied in any electronic device with two or more hinged parts, such as notebook computers, LCD monitors, DVD (digital video disk) players, and others. Hereinafter, for the purposes of conveniently describing an exemplary application, the hinge assembly described and illustrated is applied in a notebook computer.

Referring toFIGS. 1 and 2, an electronic device100includes a first main body10, a second main body20, a connecting arm30, and two hinge assemblies40connecting the first main body10and the second main body20. In the illustrated embodiment, the first main body10is the top of the notebook computer, and the second main body20is the bottom.

The first main body10forms two first connecting protrusions11at the same side of the first main body10and in a manner to leave a space therebetween. The second main body20forms two second connecting protrusions21correspondingly, and the two second connecting protrusions21are formed at the same side of the second main body20and in a manner to leave a space therebetween.

The connecting arm30is an elongated hollow body which is not longer than either the distance between two first connecting protrusions11or the distance between two second connecting protrusions21.

Referring toFIGS. 3 and 4, a hinge assembly40includes a first pivot shaft41, a second pivot shaft42, a third pivot shaft43, a first bracket44, a second bracket45, a first meshing wheel46, a second meshing wheel47, a third meshing wheel48, a transmission belt member49, a connecting member401, a plurality of first resilient members402, a plurality of second resilient members403, a first flat washer404, a second flat washer405, a first fastener406, and a second fastener407.

The first pivot shaft41includes a first shaft portion411and a first engaging portion413extending from one end of the first shaft portion411. The first shaft portion411includes a first locking part4111of a non-circular cross-section and a first rotating part4113of a circular cross-section. The first rotating part4113of the first shaft portion411is positioned between the first locking part4111and the first engaging portion413. In the illustrated embodiment, the first engaging portion413is a threaded portion.

The second pivot shaft42has the same structure as the first pivot shaft41, and thus the second pivot shaft42includes a second shaft portion421and a second engaging portion423. The second shaft portion421includes a second locking part4211of a non-circular cross-section and a second rotating part4213of a circular cross-section. The second rotating part4213of the second shaft portion421is positioned between the second locking part4211and the second engaging portion423. In the illustrated embodiment, the second engaging portion423is also a threaded portion.

The third pivot shaft43includes a head portion431and an inserting portion433. In the illustrated embodiment, the head portion431is a flange formed on an end of the inserting portion433.

The first bracket44includes a first connecting plate441and a first pivotal plate443. The first pivotal plate443bends from the first connecting plate441and defines a non-circular first axle hole4431. In the illustrated embodiment, the first pivotal plate443is substantially perpendicular to the first connecting plate441.

The second bracket45includes a second connecting plate451and a second pivotal plate453. The second pivotal plate453bends from the second connecting plate451and defines a circular second axle hole4531. In the illustrated embodiment, the second pivotal plate453is substantially perpendicular to the second connecting plate451.

Each of the first meshing wheel46, the second meshing wheel47, and the third meshing wheel48defines a plurality of teeth (not labeled) on their peripheries thereof. The first meshing wheel46defines a first central hole461, and the second meshing wheel47defines a second central hole471. The first and second central holes461,471are non-circular. The third meshing wheel48defines a third central hole481which is circular. In the illustrated embodiment, the first meshing wheel46, the second meshing wheel47, and the third meshing wheel48are gears.

The transmission belt member49is made of a flexible material. A width of the transmission belt member49is smaller than a thickness of the third meshing wheel48. The transmission belt member49forms a plurality of teeth491. In the illustrated embodiment, the transmission belt member49is a drive belt and made of plastic. The thickness of the third meshing wheel48is larger than or equal to the thickness of the second meshing wheel47and the width of the transmission belt member49combined.

The connecting member401includes a connecting portion4011and a fixing portion4012. The connecting portion4011defines a first pivotal hole4013, a second pivotal hole4014, and a third pivotal hole4015. The third pivotal hole4015is located between the first pivotal hole4013and the second pivotal hole4014, and is adjacent to the second pivotal hole4014. The connecting portion4011further forms a resisting protrusion4016around the first pivotal hole4013. The fixing portion4012extends from one side of the connecting portion4011. In the illustrated embodiment, the fixing portion4012bends from an edge of the connecting portion4011.

The first resilient members402and the second resilient members403are disk-shaped spring washers, and they may be compression springs instead.

Each of the first flat washer404and the second flat washer405define a circular central hole.

In the illustrated embodiment, the first and second fasteners406,407are a plurality of screw nuts threaded on the first and second pivot shaft41,42respectively.

During assembly of the hinge assembly40, the first shaft portion411of the first pivot shaft41passes through the first pivotal hole4013of the connecting member401and the first central hole461of the first meshing wheel46, the second shaft portion421of the second pivot shaft42passes through the second pivotal hole4014of the connecting member401and the second central hole471of the second meshing wheel47. The inserting portion433of the third pivot shaft43passes through the third pivotal hole4015of the connecting member401and the third central hole481of the third meshing wheel48, thereby the third meshing wheel48meshes with the second meshing wheel47. The first meshing wheel46is non-rotatably sleeved on the first locking part4111of the first pivot shaft41, the second meshing wheel47is non-rotatably sleeved on the second locking part4211of the second pivot shaft42, and the third meshing wheel48is rotatably sleeved on the inserting portion433of the third pivot shaft43.

The head portion431resists on one side of the connecting portion4011of the connecting member401which is away from the resisting protrusion4016. The transmission belt member49is sleeved on the first meshing wheel46and the third meshing wheel48, and the transmission belt member49mesh with both of the first meshing wheel46and the third meshing wheel48.

The first locking part4111of the first pivot shaft41passes through the first axle hole4431of the first bracket44, and the second locking part4211of the second pivot shaft42passes through the second axle hole4531of the second bracket45. The first bracket44and the second bracket45are non-rotatably sleeved on the first pivot shaft41and the second pivot shaft42, respectively.

The first engaging portion413passes through the first resilient members402and the first flat washer404, and engages with the first fastener406. The second engaging portion423passes through the second resilient members403and the second flat washer405, and engages with the second fastener407in the same manner. Accordingly, one hinge assembly40is assembled, and the other hinge assembly40is assembled in the same manner.

In the hinge assembly40, the first pivot shaft41, the second pivot shaft42, and the third pivot shaft43are substantially parallel to one another. The connecting portion4011of the connecting member401is sleeved on the first rotating part4113of the first pivot shaft41and the second rotating part4213of the second pivot shaft42, whereby the connecting member401is rotatably sleeved on the first pivot shaft41and the second pivot shaft42. The connecting member401is non-rotatably sleeved on the third pivot shaft43; and the third meshing wheel48rotates synchronously with the third pivot shaft43. One end of the first meshing wheel46resists the resisting protrusion4016of the connecting member401, and the other end resists the first bracket44. One end of the second meshing wheel47resists the connecting member401, and the other end resists one end of the transmission belt member49.

Also referring toFIGS. 1 and 2, during in assembly of the electronic device100, one hinge assembly40is partially received in the connecting arm30from one end of the connecting arm30and the fixing portion4012of the connecting member401is locked with the connecting arm30by a plurality of fasteners (not shown). The first bracket44and the second bracket45of the hinge assembly40are exposed beyond the connecting arm30. The other hinge assembly40is assembled to the other end of the connecting arm30in the same manner. The first connecting plates441of the first brackets44of two of the hinge assemblies40are fixed to the first connecting protrusions11of the first main body10; and the second connecting plates451of the second brackets45of the two hinge assemblies40are fixed to the second connecting protrusions21of the second main body20. Accordingly, the electronic device100is assembled.

In use, when a rotating force is applied on the first main body10, the first main body10with the first bracket44of each hinge assembly40drives the first pivot shaft41to rotate in the same direction. When the first pivot shaft41rotates, the first meshing wheel46rotates synchronously. During the rotation of the first meshing wheel46, some of the teeth of the first meshing wheel46mesh with the transmission belt member49, and some of the teeth of the first meshing wheel46disengage from the transmission belt member49, such that the transmission belt member49rotates together with the first meshing wheel46. The third meshing wheel48is driven by the transmission belt member49to rotate together with the transmission belt member49. During the rotation of the third meshing wheel48, different teeth of the second meshing wheel47mesh with the third meshing wheel48, whereby, the second meshing wheel47is rotated by the third meshing wheel48in a reverse direction relative to the rotation direction of the third meshing wheel48. Furthermore, the second meshing wheel47rotates the second pivot shaft42and the second bracket45together in the same direction as the second meshing wheel47. Moreover, the second main body20rotates together with the second bracket45.

Since the third meshing wheel48rotates in the same direction as the first main body10, and the second meshing wheel47rotates in the same direction with the second main body20, whereas the third meshing wheel48and the second meshing wheel47rotate in reverse directions, the first main body10and the second main body20rotate in reverse directions relative to each other to open or close.

In the electronic device100, both of the first main body10and the second main body20rotate when a rotating force is applied on either the first main body10or the second main body20. Thereby, the electronic device100is capable of being opened or closed faster at double-speed. Furthermore, lesser force needs to be applied on the electronic device100to open or close.

In the electronic device100, only one meshing wheel, that is the third meshing wheel48, meshes with other elements on both sides, furthermore, the transmission belt member49is a belt which is capable of allowing an acceptable amount of deformation within tolerance range, such that the hinge assembly40cannot choke during rotating.

The transmission belt member49is made of flexible material, such as the plastic, therefore, the hinge assembly40is capable of rotating smoothly, with little noise and of good handling.

The resisting protrusion4016of the connecting member401ensures that the first meshing wheel46cannot move along the first pivot shaft41between the first bracket44and the connecting portion4011of the connecting member401. Thereby, the first meshing wheel46meshes with the transmission belt member49stably.

In alternative embodiments, the connecting arm30of the electronic device100may be omitted, instead, the first bracket44and the second bracket45of each of the hinge assembly40is fixed to the first main body10and the second main body20, respectively. The fixing portion4012of the connecting member401may be omitted correspondingly. The third pivot shaft43may have a non-circular cross-section and the third meshing wheel48defines a non-circular central hole correspondingly, furthermore, the connecting member401is rotatably sleeved on the third pivot shaft43, such that the third pivot shaft43and the third meshing wheel48are capable of rotating relative to the connecting member401. The number of hinge assemblies40may be one, three or more.