1. Field of the Invention
The present invention generally relates to hinge assemblies and, more particularly, to a hinge assembly for hinging together housings of foldable electronic devices such as mobile telephones, electronic notebooks, and so on.
2. Discussion of the Prior Art
With the development of wireless communication technology and information processing technology, portable electronic devices such as mobile telephones and electronic notebooks are now in widespread use. These electronic devices enable consumers to enjoy the convenience of high technology services anytime and anywhere. Foldable electronic devices are particularly favored by consumers for their convenience.
Generally, foldable electronic devices have most of the electronics in one housing, called the body. The other housing, called the cover, normally contains fewer electronic components than the body. Other foldable electronic devices have all the electronics in the body, thus the cover contains no electronics and serves only to cover a keypad and a display of the body. Various types of hinge assemblies are used to join the body and the cover of a foldable electronic device, so that the cover can unfold up from and fold down upon the body.
A typical hinge assembly used in small foldable electronic devices includes a shaft, a fixing member, a fixed cam, a rotary sliding cam, and a compression spring. An end portion of the shaft is extended through the fixed cam, the rotary sliding cam, the compression spring, and the fixing member in that order, thereby integrating the hinge assembly into a modular unit. While opening or closing the foldable electronic device, a large friction force is produced between the shaft, the fixed cam, and the rotary sliding cam. The friction force can potentially damage the shaft and the fixed cam, thus reducing the working lifetime of the hinge assembly.
What is needed, therefore, is a hinge assembly which overcomes the above-described shortcomings.
In a preferred embodiment described herein, a hinge assembly for a foldable electronic device is provided. The hinge assembly includes a shaft, a barrel portion, and a plurality of roll elements. The shaft has an outer screw thread formed at one end thereof. The barrel portion has an inner screw thread and a groove formed in the inner surface thereof. The inner screw thread is threadingly engaged with the outer screw thread of the shaft. The roll elements are received in the groove of the barrel portion, and are rotatable relative to the shaft and the barrel portion.
Other advantages and novel features of various embodiments will become more apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings.
Other aspects of the present hinge assembly can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the hinge assembly and its potential applications. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The positioning element 100 is substantially ring-like in form, and the positioning element 100 has a circular hole 102 defined through a center portion thereof. A pair of opposed arc positioning protrusions 104 protrudes from one side surface of the positioning element 100 that faces the barrel portion 200. Each positioning protrusion 104 has a wedging surface 106 with a higher end and a lower end with respect to the side surface of the positioning element 100. The higher end of the wedging surface 106 of one positioning protrusion 104 is opposed to the higher end of the other positioning protrusion 104, and is adjacent to the lower end of the other positioning protrusion 104. A pair of opposed positioning slots 108 is defined through an edge the positioning element 100.
Also referring to
The shaft 400 is essentially in the form of a round rod and the shaft 400 has a shaft body 402. An outer screw thread 404 is formed at one end of the shaft body 402. The outer screw thread 404 is perferrably double-threaded. The outer screw thread 404 is configured for threadedly engaging with the inner screw thread 207 of the barrel portion 200. A keyed head 406 is formed at the other opposite end of the shaft body 402, and the keyed head 406 has a pair of opposite planar surfaces and a pair of opposite arc surfaces connecting the planar surfaces. The keyed head 406 is configured for engaging with the body 701 of the foldable electronic device 70 so that the shaft 400 is rotatable with the body 701. The keyed head 406 defines a pair of opposite arc slots 408 in each of the arc surfaces thereof.
The compression spring 500 is perferrably made of metal and is spiral-shaped (i.e. a coil spring). The disk 600 has a disk hole 602 defined through a center portion thereof. The disk 600 is configured for mounting on the shaft 400 in the arc slots 408. Alternatively, the disk 600 may be integrally formed as part of the shaft 400.
Referring to
To close the foldable electronic device 70, the cover 702 is manually rotated towards the body 701. As such, the barrel portion 200 rotates relative to the shaft 400. By the engagement between the inner screw thread 207 of the barrel portion 200 and the outer screw thread 404 of the shaft 400, the barrel portion 200 is pushed axially towards the disk 600. During this process, the compression spring 500 is compressed further. When the foldable electronic device 70 is in a closed position, the cover 702 is held by a locking mechanism (not shown), and a force of the spring 500 is stored.
To open the foldable electronic device 70, the locking mechanism is manually unlocked. The compression spring 500 then decompresses, driving the barrel portion 200 to move relative to the shaft 400. The cover 702 is correspondingly rotated upward from the body 701 and is rotated in an opening direction under the decompression force of the compression spring 500. The cover 802 is thus opened automatically to the fully open position as shown in
As described above, the preferred embodiment provides a hinge assembly for devices such as foldable mobile phones. When the cover is opened or closed, a part of the outer screw thread of the shaft slides on the ball bearings, which are received in the grooves of the inner screw thread of the barrel portion. In this way, the fiction between the shaft and the barrel portion is minimized, thus prolonging the working lifetime of the hinge assembly.
It is to be understood that the compression spring 500 may alternatively be made of another material (e.g. plastic or rubber). The compression spring 500 may alternatively have a different configuration, for example, a leaf spring or a resilient cylinder. The ball bearings 300 may alternatively have a different configuration (e.g. small column).
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages. The examples hereinbefore described are merely preferred or exemplary embodiments of the invention.
Number | Date | Country | Kind |
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200510034495.0 | Apr 2005 | CN | national |