Patent Application
20150267450
The present invention relates to a double-axis hinge and particularly to a synchronous moving double-axis hinge that provides steady opening and closing.
A conventional flip electronic device such as a notebook computer, mobile phone or the like generally has a hinge to bridge a display and a body to allow the display to be opened or closed against the body, and also provide a torsional force to support and anchor the display at a desired angle after being opened. In the past, the hinge usually was a single-axis hinge with only one shaft as an axis. Although it allows the display to be flipped against the body, the display and body interfere with each other when the display has been opened at a certain angle, hence it limits use angle of the electronic device. Nowadays touch control electronic devices equipped with a keyboard and a touch screen are very popular. Aside from using the keyboard to do input as usual, flipping the screen and keyboard-attached body inversely to perform touch input also is a commonly required function. As a result, the conventional single-axis hinge no longer meets the present market requirement, so that double-axis hinges have been developed.
For instance, Taiwan patent No. 1255388 discloses a hinge structure which includes a first shaft fastened to a first frame, a first gear coupled on the perimeter of the first shaft, a second shaft fastened to a second frame and a second gear coupled on the perimeter of the second shaft. The first gear and second gear engage with each other. The first shaft and second shaft are turned in opposite directions at the same time. The gears of the hinge structure can be spur gears or bevel gears.
The aforesaid hinge structure is a double-axis hinge using the spur gears or bevel gears. However, in the event that the axes of the spur gears or bevel gears and the collaborated gears are not parallel to result in eccentricity or the gear teeth are not parallel, the teeth of the gears can only form point contact between them that tends to generate impact and friction between the gear teeth and shorten the lifespan of the spur gears or bevel gears. Hence how to improve the double-axis hinge to provide steady transmission is an issue yet to be resolved in the industry.
The primary object of the present invention is to solve the problem of the conventional double-axis hinge that gears easily generate impact and friction between them because of tolerances.
To achieve the foregoing object, the present invention provides a synchronous moving double-axis hinge that comprises a support member, a first transmitting assembly, a second transmitting assembly and a transmission element. The support member includes a main body, a first hinge hole and a second hinge hole formed on the main body, and at least one holding portion located on the main body between the first and second hinge holes. The holding portion has an installation section. The first and second transmitting assemblies are mounted on the support member. The first transmitting assembly has a first transmission shaft hinged in the first hinge hole and a first helical gear annularly coupled on the surface of the first transmission shaft. The second transmitting assembly has a second transmission shaft hinged in the second hinge hole and a second helical gear annularly coupled on the surface of the second transmission shaft. The transmission element is installed on the holding portion of the support member, and includes a hinge pin hinged on the installation section and a driven helical gear fixedly mounted onto the hinge pin. The driven helical gear has a first engaging zone to engage with the first helical gear and a second engaging zone opposing to the first engaging zone to engage with the second helical gear. The first transmission shaft has a first extension axis, and the second transmission shaft has a second extension axis parallel with the first extension axis. The hinge pin of the transmission element has a third extension axis crossing with the first and second extension axes.
In one embodiment the first transmission shaft has a first latch portion and the first helical gear has a first coupling portion to latch on the first latch portion.
In another embodiment the first transmission shaft has a first retaining portion leaning on the first helical gear and collaborating with the support member to confine movement of the first helical gear on the first transmission shaft.
In yet another embodiment the first transmission shaft has a first fastening base.
In yet another embodiment the second transmission shaft has a second latch portion and the second helical gear has a second coupling portion to latch on the second latch portion.
In yet another embodiment the second transmission shaft has a second retaining portion leaning on the second helical gear and collaborating with the support member to confine movement of the second helical gear on the second transmission shaft.
In yet another embodiment the second transmission shaft has a second fastening base.
In yet another embodiment the first transmitting assembly includes a first torsional force generation portion run through by the first transmission shaft to provide a torsional force required by the first transmission shaft. The second transmitting assembly includes a second torsional force generation portion run through by the second transmission shaft to provide another torsional force required by the second transmission shaft.
In yet another embodiment the first helical gear, second helical gear and driven helical gear have respectively a plurality of helical teeth. The helical teeth of the first helical gear, second helical gear and driven helical gear are formed in a same helical direction.
The double-axis hinge of the invention thus formed, compared with the conventional structures, provides features as follows:
1. The invention employs crossed helical gears to overcome the problem of the spur gears or bevel gears caused by tolerance in the conventional technique. In the conventional technique, in the event that the axes of the spur gears or bevel gears and the collaborated gears are not parallel to result in eccentricity or the gear teeth are not parallel, the teeth of the gears can only form point contact between them that tends to generate impact and friction between the gear teeth and shorten the lifespan of the spur gears or bevel gears. The crossed helical gears of the invention can overcome the aforesaid flaws by providing curved teeth profile to form close contact between the gear teeth to improve the shortcoming of impact and friction that might otherwise occur.
2. The invention provides synchronous movements of two shafts through the crossed helical gears. The crossed helical gears have smaller gaps between the helical teeth to provide a shorter idle displacement. Hence before the engaged teeth separate from each other, the next set of teeth are engaged already. Thus the helical teeth of the crossed helical gears can effectively amplify the contact among the gear teeth to provide steadier transmission.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
Please refer to
To facilitate discussion of operation of the synchronous moving double-axis hinge of the invention, it is to be noted that the first transmitting assembly 2 can be driven to drive the second transmitting assembly 3, or the second transmitting assembly 3 can be driven to drive the first transmitting assembly 2, or the first and second transmitting assemblies 2 and 3 can be driven at the same time to transmit each other. The discussion below illustrates merely an instance in which the first transmitting assembly 2 is turned to drive the transmission element 4 which in turn drives the second transmitting assembly 3, but this is not the limitation of the invention. When the first transmission shaft 21 of the first transmitting assembly 2 is turned, the first helical gear 22 latched thereon is driven to drive the driven helical gear 42 of the transmission element 4; then the driven helical gear 42 further drives the second helical gear 32 of the second transmitting assembly 3 that in turn drives the second transmission shaft 31 latched thereon. Hence when the first transmitting assembly 2 is turned, the second transmitting assembly 3 also is turned accordingly.
Please refer to
As a conclusion, the synchronous moving double-axis hinge of the invention can provide synchronous rotation of the first transmitting assembly 2 and second transmitting assembly 3 through the transmission element 4. In addition, the first helical gear 22, second helical gear 32 and driven helical gear 42 are crossed helical gears each has a helical teeth profile formed in a curved surface. As the gap between the teeth is smaller, the crossed helical gears can contact with each other more closely. As a result, the contact among the gear teeth can be effectively amplified to provide steadier transmission.
