Dual-shaft synchronous movement device

A dual-shaft synchronous movement device includes a first shaft and a second shaft, which are synchronously rotatable. The synchronous movement device further includes a first rotor and/or a third rotor disposed on the first shaft and a second rotor and/or a fourth rotor disposed on the second shaft, and an inextensible/non-contractible flexible plate connected between the first (or the third rotor) and the second rotor (or the fourth rotor). When the first shaft drives the first rotor (or the third rotor) to rotate, the inextensible/non-contractible flexible plate pulls the second rotor (or the fourth rotor) to rotate in a direction reverse to a moving direction of the first rotor so as to make the first and second shafts synchronously rotate. The synchronous movement device solves the problem of delay of kinetic energy transmission and the problem of slippage, deflection and untrue operation of the conventional device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an improved dual-shaft synchronous movement device. The dual-shaft synchronous movement device includes a first shaft and a second shaft and an assembly of rotors and cooperative inextensible/non-contractible flexible plates wound on the rotors. In operation, the first and second shafts are synchronously rotated to overcome the problem of the conventional transmission mechanism that the wires are likely to slip or deflect from the rollers.

2. Description of the Related Art

There are various electronic apparatuses provided with covers or display screens or viewers, such as mobile phones, notebooks, PDA, digital imagers and electronic books. The covers or display screens or viewers are pivotally mounted on the electronic apparatuses via pivot pins or rotary shafts, whereby the covers or display screens or viewers can be freely rotated and opened/closed under external force.

In order to operate the display module (such as the screen) and/or the apparatus body module of the electronic apparatus in more operation modes and application ranges, a dual-shaft mechanism is provided between the display module and the apparatus body module, whereby the display module and/or the apparatus body module can be operated in different operation modes by different rotational angles.

There is also a conventional mechanism composed of rollers and drive wires for transmitting force to the rotary shaft so as to rotate the rotary shaft. As known by those who are skilled in this field, during the operation process of the wires or the transmission belts, delay of kinetic energy transmission will take place. This is because the wires contact the rollers by points or lines or there is a gap between the wires and the rollers so that the wires are likely to slip or up and down deflect from the rollers. Under such circumstance, the wires will untruly operate to cause error. Also, the wires are made of elastic material and the fixing structure for assembling the wires with the rollers is not ideal. As a result, in force transmission, the load on the wires or the pulling force applied to the wires will increase. In this case, the transmission effect of the wires will be deteriorated and the wires may detach from the rollers. Especially, after a period of use, the force of the wires, which is preset in the assembling process will decrease due to elastic failure. Under such circumstance, the synchronous movement effect of the transmission mechanism will be deteriorated.

There is another problem existing in the application and manufacturing of the wires. That is, during the assembling process of the wires, the wires need to be tensioned. This will make it more difficult to control the quality of wiring and assembling. Therefore, the ratio of good products can be hardly promoted and the assembling time can be hardly shortened. As a result, the manufacturing cost is increased.

In order to improve the above problems, a conventional dual-shaft synchronous movement device has been developed. Such dual-shaft synchronous movement device employs multiple gears for transmitting force. However, as known by those who are skilled in this field, with the transmission gears, the gap between the shafts of the dual-shaft synchronous movement device can be hardly minified. Therefore, the entire transmission unit or structure will occupy a considerably large space. Especially, when the transmission unit is applied to a notebook or a miniaturized electronic device, the electronic device can hardly meet the requirement for lightweight and slimmed design. This is not what we expect.

The conventional rotary shaft structures and the relevant connection components thereof have some shortcomings in use and structural design that need to be overcome. It is therefore tried by the applicant to provide a dual-shaft synchronous movement device to eliminate the shortcomings existing in the conventional rotary shaft structure so as to widen the application range and facilitate the assembling process of the rotary shaft structures.

The dual-shaft synchronous movement device of the present invention has the following advantages:1. The synchronous movement device of the present invention is mounted between the display module and the apparatus body module. When an operator 0°˜180° rotates the display module, the apparatus body module is synchronously relatively 0°˜180° rotated. Therefore, the total rotational angle of the display module and the apparatus body module is 360°. Accordingly, the operator can more quickly and conveniently operate the electronic apparatus in more operation modes (or application ranges). Also, the synchronous movement effect and operational stability of the synchronous movement device and the cooperative rotary shafts are enhanced.2. The synchronous movement device of the present invention overcomes the problem of delay of kinetic energy transmission of the conventional wires. The synchronous movement device of the present invention also solves the problem of the conventional transmission mechanism that the wires contact the rollers by points or lines so that the wires are likely to slip or up and down deflect from the rollers and the wires will untruly operate to cause error. The synchronous movement device of the present invention also solves the problem of the conventional transmission mechanism that the fixing structure for assembling the wires with the rollers is not ideal so that in force transmission, the load on the wires or the pulling force applied to the wires will increase to deteriorate the transmission effect and the wires may detach from the rollers.3. The synchronous movement device or transmission mechanism of the present invention is free from any gear for transmitting force as in the conventional technique. Therefore, the gap between the shafts can be as minified as possible. Therefore, the space occupied by the entire transmission unit or structure is reduced. Accordingly, when the transmission unit is applied to an electronic device, the electronic device can meet the requirement for lightweight and slimmed design.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide a dual-shaft synchronous movement device includes a first shaft and a second shaft, which are synchronously rotatable. The synchronous movement device further includes a first rotor and/or a third rotor disposed on the first shaft and a second rotor and/or a fourth rotor disposed on the second shaft, and an inextensible/non-contractible flexible plate connected between the first (or the third rotor) and the second rotor (or the fourth rotor). When the first shaft drives the first rotor (or the third rotor) to rotate, the inextensible/non-contractible flexible plate pulls the second rotor (or the fourth rotor) to rotate in a direction reverse to a moving direction of the first rotor so as to make the first and second shafts synchronously rotate. The synchronous movement device solves the problem of delay of kinetic energy transmission and the problem of slippage, deflection and untrue operation of the conventional device.

In the above dual-shaft synchronous movement, each of the first rotor (and/or the third rotor) and the second rotor (and/or the fourth rotor) has a support and a main body enclosing the support. The inextensible/non-contractible flexible plate has a first end and a second end. The first end of the inextensible/non-contractible flexible plate is fixed with the support of the first rotor (or the third rotor) and wound on the main body of the first rotor (or the third rotor). The second end of the inextensible/non-contractible flexible plate is fixed with the support of the second rotor (or the fourth rotor) and wound on the main body of the second rotor (or the fourth rotor). The first and second rotors (or the third and fourth rotors) contact the cooperative inextensible/non-contractible flexible plates by faces to transmit force. Accordingly, the torque change and deflection of the inextensible/non-contractible flexible plates are minimized and the first and second shafts can be smoothly rotated. Moreover, once the rotational force disappears, the shafts stop rotating to be located in a desired position.

In the above dual-shaft synchronous movement, the support has a shaft hole. The first shaft is fitted in the shaft holes of the first and third rotors and the second shaft is fitted in the shaft holes of the second and fourth rotors. An extension section extends from a middle section of the support for fixing the first and second ends of the inextensible/non-contractible flexible plate. The inextensible/non-contractible flexible plate has such a length that after the first rotor is 180° rotated along with the first shaft (or the second rotor is 180° rotated along with the second shaft), the first end (or the second end) of the inextensible/non-contractible flexible plate is still wound on the first rotor (or the second rotor) by a length larger than ½ circumferential length of the main body of the first rotor (or the main body of the second rotor).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer toFIGS. 1,2and3. The dual-shaft synchronous movement device of the present invention includes a first shaft10and a second shaft20. The first and second shafts10,20are assembled with each other and disposed in a casing30. Each of the first and second shafts10,20has a fixed end10a,20aand a pivoted end10b,20b. Through fixing seats (not shown), the fixed ends10a,20aof the first and second shafts10,20are respectively fixed on a display module91and an apparatus body module92of an electronic apparatus90(such as a mobile phone or a computer).

Referring toFIGS. 1 and 2, the pivoted end10bof the first shaft10is provided with a first rotor11(and/or a third rotor33) and the pivoted end20bof the second shaft20is provided with a second rotor22(and/or a fourth rotor44). Inextensible/non-contractible flexible plates50(and/or60) are disposed between the first and second rotors11,22(and/or the third and fourth rotors33,44). The first and second rotors11,22(and/or the third and fourth rotors33,44) and the inextensible/non-contractible flexible plates50(and/or60) are assembled on the first and second shafts10,20via a fixing assembly80.

In this embodiment, each of the first, second, third and fourth rotors11,22,33,44has a support a and a main body b enclosing the support a. The support a has a shaft hole c. The shaft hole c has a configuration identical to the cross-sectional shape of the pivoted ends10b,20bof the first and second shafts. For example, as shown in the drawings, the pivoted ends10b,20bof the first and second shafts (or the shaft holes c) have a rectangular cross section and the pivoted ends10b,20bof the first and second shafts10,20are connected in the shaft holes c, whereby the first and third rotors11,33are rotatable along with the first shaft10and the second and fourth rotors22,44are rotatable along with the second shaft20.

Please refer toFIGS. 2 and 3. The inextensible/non-contractible flexible plate50is disposed between the first and second rotors11,22. The inextensible/non-contractible flexible plate60is disposed between the third and fourth rotors33,44. To speak more specifically, the inextensible/non-contractible flexible plates50,60are (flexible) metal plates or steel plates. Each of the inextensible/non-contractible flexible plates50,60has a first end51,61and a second end52,62. The first end51of the inextensible/non-contractible flexible plate50is fixedly wound on the main body b of the first rotor11. The second end52of the inextensible/non-contractible flexible plate50is fixedly wound on the main body b of the second rotor22. The first end61of the inextensible/non-contractible flexible plate60is fixedly wound on the main body b of the third rotor33. The second end62of the inextensible/non-contractible flexible plate60is fixedly wound on the main body b of the fourth rotor44.

Please refer toFIGS. 2 and 2A. An extension section d extends from a middle section of each support a for fixing the first ends51,61and second ends52,62of the inextensible/non-contractible flexible plates50,60. To speak more specifically, the first ends51,61of the inextensible/non-contractible flexible plates50,60are fixedly welded on the extension sections d of the supports of the first and third rotors11,33. The inextensible/non-contractible flexible plates50,60extend out of the main bodies b through slits e formed on the main bodies b to be wound around the main bodies b of the first and third rotors11,33. The second ends52,62of the inextensible/non-contractible flexible plates50,60are fixedly welded on the extension sections d of the supports of the second and fourth rotors22,44. The inextensible/non-contractible flexible plates50,60extend out of the main bodies b through slits e formed on the main bodies b to be wound around the main bodies b of the second and fourth rotors22,44.

It should be noted that as shown inFIG. 2A, after the first and second ends51,61,52,62of the inextensible/non-contractible flexible plates50,60are fixedly welded on the extension sections d of the supports a and extended out of the main bodies b through the slits e, the direction in which the inextensible/non-contractible flexible plates50,60are wound on the main bodies b is not limited. This facilitates the assembling process.

According to the above arrangement, the first and second rotors11, (or the third and fourth rotors33,44) contact the inextensible/non-contractible flexible plates50,60by faces to transmit torque. In this case, the torque change and up and down deflection of the inextensible/non-contractible flexible plates50,60are minimized and the first and second rotors10,20can be smoothly rotated. Moreover, once the rotational force disappears, the shafts stop rotating to be located in a desired position.

Please refer toFIGS. 2 and 3. The inextensible/non-contractible flexible plate50is wound on the first and second rotors11,22in a direction reverse to the direction in which the inextensible/non-contractible flexible plate60is wound on the third and fourth rotors33,44. For example,FIG. 3shows that the inextensible/non-contractible flexible plate50is wound from the left side of the first rotor11(according to the drawing) to the right side of the second rotor22in a direction reverse to the direction in which the inextensible/non-contractible flexible plate60is wound from the right side of the third rotor33to the left side of the fourth rotor44. According to the above arrangement, the first and second shafts10,20will rotate in different directions.

Please refer toFIGS. 3 and 4, which show that the display module is closed onto the apparatus body module92with the angle contained therebetween 0°. When an operator opens the display module91to make the first shaft10drive the first rotor11(or the third rotor33) to clockwise rotate according to the drawing, the inextensible/non-contractible flexible plate50drives the second rotor22to forcedly make the second shaft20rotate in a direction reverse to the moving direction of the first rotor11, (that is, counterclockwise rotate). When the second shaft20is driven by the first shaft10to counterclockwise rotate, the fourth rotor44is simultaneously forcedly counterclockwise rotated, whereby the inextensible/non-contractible flexible plate60drives the third rotor33to (clockwise) rotate. Accordingly, the first and second shafts10,20are synchronously rotated. Also, when the first shaft10is counterclockwise rotated, via the inextensible/non-contractible flexible plate60, the third rotor33drives the fourth rotor44to make the second shaft20clockwise rotate. Accordingly, the first and second shafts10,20are synchronously rotated.

Therefore, as shown inFIG. 5, when the operator opens the display module91to make the first shaft10clockwise rotate to a 135° position, the first, second, third and fourth rotors11,22,33, cooperate with the inextensible/non-contractible flexible plates50,60to transmit the force and make the second shaft20as well as the apparatus body module92synchronously counterclockwise rotate to a 135° position. That is, the display module91and the apparatus body module92are totally relatively rotated by 270°.FIG. 6shows that when the operator opens and clockwise rotates the display module91to a 180° position, the apparatus body module92is synchronously counterclockwise rotated to a 180° position. That is, the display module91and the apparatus body module92are totally relatively rotated by 360°.

That is, by means of the synchronous movement device, a user can operate and rotate the display module91by a certain angle or range to achieve a travel double the rotational angle or range. Accordingly, the user can more quickly and conveniently operate the electronic apparatus.

In a preferred embodiment, the inextensible/non-contractible flexible plate50has such a length that after the first rotor11is 180° rotated along with the first shaft10(or the second rotor22is 180° rotated along with the second shaft20), the first end51(or the second end52) of the inextensible/non-contractible flexible plate50is still wound on the first rotor11(or the second rotor22) by a length larger than ½ circumferential length of the main body b of the first rotor11(or the main body b of the second rotor22).

It should be noted that the inextensible/non-contractible flexible plate60has such a length that after the third rotor33is 180° rotated along with the first shaft10(or the fourth rotor44is 180° rotated along with the second shaft20), the first end61(or the second end62) of the inextensible/non-contractible flexible plate60is still wound on the third rotor33(or the fourth rotor44) by a length larger than ½ circumferential length of the main body b of the third rotor33(or the main body b of the fourth rotor44).

It should be noted that the inextensible/non-contractible flexible plate50(or60) is tightly wound on the first and second rotors11,22(or the third and fourth rotors33,44) to transmit the force. During the force transmission process, the possibility of torque change is minimized so that the first and second shafts10,20can be smoothly rotated. Moreover, once the rotational force disappears, the shafts stop rotating to be located in a desired position.

In comparison with the conventional device, the dual-shaft synchronous movement device of the present invention has the following advantages:1. The rotary shafts (the first and second shafts10,20) and the relevant components (such as the first and second rotors11,22and the inextensible/non-contractible flexible plate50wound thereon and the third and fourth rotors33,44and the inextensible/non-contractible flexible plate60wound thereon) together form a synchronous movement mechanism. This structure is apparently different from the conventional device, which employs multiple gears for transmitting force.2. The first and second rotors11,22(or the third and fourth rotors33,44) and the cooperative inextensible/non-contractible flexible plate50(or60) wound thereon together form a transmission structure of the synchronous movement mechanism. The synchronous movement mechanism is mounted between the display module91and the apparatus body module92. When an operator 0°˜180° rotates the display module91, the apparatus body module92will synchronously relatively rotate by 0°˜180°. Accordingly, the total rotational angle of the display module91and the apparatus body module92is 360°. That is, by means of the synchronous movement device, a user can operate and rotate the display module91by a certain angle or range to achieve a travel double the rotational angle or range. Accordingly, the user can more quickly and conveniently operate the electronic apparatus in more operation modes (or application ranges).3. The first and second rotors11,22(or the third and fourth rotors33,44) and the cooperative inextensible/non-contractible flexible plate50(or60) wound thereon together form a transmission structure of the synchronous movement mechanism. Accordingly, the gap between the rotary shafts (the first and second shafts10,20) is as minified as possible. Therefore, the space occupied by the entire transmission unit or structure is reduced. Accordingly, when the transmission unit is applied to an electronic device, the electronic device can meet the requirement for lightweight and slimmed design.4. The middle sections of the supports a of the first, second, third and fourth rotors11,22,33,44have the extension sections d. After the first and second ends51,61,52,62of the inextensible/non-contractible flexible plates50,60are fixedly welded on the extension sections d of the supports a and extended out of the main bodies b through the slits e, the direction in which the inextensible/non-contractible flexible plates50,60are wound on the main bodies b is not limited. This facilitates the assembling process.5. Especially, the first and second rotors11,22(or the third and fourth rotors33,44) contact the cooperative inextensible/non-contractible flexible plates50,60by faces to transmit force. Accordingly, the torque is more uniformly distributed over the inextensible/non-contractible flexible plates50,60to reduce the load per unit. In this case, the torque change and up and down deflection of the inextensible/non-contractible flexible plates50,60are minimized and the first and second shafts10,20can be smoothly rotated. Therefore, the synchronous movement device of the present invention overcomes the problem of delay of kinetic energy transmission of the conventional wires and the problem of the conventional transmission mechanism that the wires contact the rollers by points or lines so that the wires are likely to slip or deflect from the rollers and the wires will untruly operate to cause error. The synchronous movement device of the present invention also solves the problem of the conventional transmission mechanism that the fixing structure for assembling the wires with the rollers is not ideal so that in force transmission, the load on the wires or the pulling force applied to the wires will increase to deteriorate the transmission effect and the wires may detach from the rollers.

In conclusion, the dual-shaft synchronous movement device of the present invention is different from and advantageous over the conventional device.