The present invention relates to a keyswitch, and more specifically, to a keyswitch utilizing blocks formed on a cap or plates of a lifting mechanism to block deformation of the plates.
A keyboard, which is the most common input device, could be found in variety of electronic apparatuses for users to input characters, symbols, numerals and so on. Furthermore, from consumer electronic products to industrial machine tools, they are all equipped with a keyboard for performing input operations.
A conventional keyswitch usually adopts the design that an elastic member is disposed between a cap and a board. In such a manner, after the cap is pressed, the elastic member could provide elastic force to drive the cap back to its original position via linkage of a lifting mechanism (e.g. a scissor support mechanism). Because the elastic member is usually made of rubber material, elastic fatigue of the elastic member may occur after the elastic member is used over a long period of time so as to shorten the life of the keyswitch.
In general, a magnetic attraction design can be utilized to solve the aforesaid problem. For example, the keyswitch could adopt the design that the lifting mechanism is composed of two plates pivoted to the board and opposite to each other. In this design, one plate has a magnetic member disposed thereon and the other plate has an abutting part to abut under the magnetic member for generating the plate linkage effect, and the other magnetic member is disposed on the board. Accordingly, when the cap is pressed by an external force, the two plates are pivoted relative to the board to raise the abutting part to drive the magnetic member on the plate away from the magnetic member on the board. When the external force is released, a magnetic attraction force between the two magnetic members drives the two magnetic members to approach each other, so as to move the cap back to its original position for generating the automatic returning effect.
However, since deformation of the two plates usually occurs when a user exerts excessive pressing force on the cap, it may dislocate the abutting part to be located above the magnetic member on the plate, which causes failure of linkage between the two plates or structural jamming of the two plates. Thus, operational stability of the keyswitch is influenced greatly.
The present invention provides a keyswitch including a board, a cap, a lifting mechanism, a returning device, a first plate, and a second plate. The cap has a long axis. The lifting mechanism is disposed between the board and the cap. The cap is movable between a pressed position and a non-pressed position relative to the board via the lifting mechanism. The lifting mechanism includes a first plate and a second plate. The first and second plates are opposite to each other. The first plate is pivotably connected to the board and abuts against the cap. The first plate has a first middle section and a first tail section. The second plate has a second middle section and a second tail section. The first middle section and the second middle section are adjacent to a center point of the long axis. The first tail section and the second tail section are adjacent to a terminal point of the long axis. The returning device is located between the first plate and the second plate. The returning device includes a first magnetic member and a second magnetic member. The first magnetic member extends from the first middle section toward the second plate. The second magnetic member is disposed on the board corresponding to the first magnetic member. An abutting part extends from the second middle section toward the first plate to abut under the first magnetic member. The first block is formed on one of the cap and the first tail section to be spaced from the other one of the cap and the first tail section. The second block is formed on one of the cap and the second tail section to be spaced from the other one of the cap and the second tail section. When the cap is pressed to deform the first plate and the second plate, the first tail section and the second tail section slide relative to the cap to a position where the other one of the cap and the first tail section abuts against the first block and the other one of the cap and the second tail section abuts against the second block, for limiting the abutting part to be located under the first magnetic member when the cap is released. When the cap is not pressed, a magnetic attraction force between the first magnetic member and the second magnetic member keeps the cap at the non-pressed position. When the cap is pressed to move the first magnetic member away from the second magnetic member with pivoting of the first plate relative to the board and tilt the abutting part, the cap moves from the non-pressed position to the pressed position together with the lifting mechanism. When the cap is released, the magnetic attraction force drives the first magnetic member to approach the second magnetic member to move the cap from the pressed position back to the non-pressed position together with the lifting mechanism.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Please refer to
Please refer to
In this embodiment, the first block 20 and the second block 22 are preferably formed on the cap 14 and are spaced from the first tail section 38 and the second tail section 44 respectively, and the third block 24 and the fourth block 26 are preferably formed on the cap 14 and are spaced from the third tail section 40 and the fourth tail section 46 respectively. The first block 20 could be preferably in a wedge shape (but not limited thereto) and could be a stripe-shaped block structure continuously formed on the cap 14 (as shown in
Via the aforesaid designs, when the cap 14 is not pressed, the first magnetic member 48 magnetically attracts the second magnetic member 50 to keep the cap 14 at the non-pressed position as shown in
On the other hand, if deformation of the first plate 28 and the second plate 30 occurs when the user exerts excessive pressing force on the cap 14, the first tail section 38, the second tail section 44, the third tail section 40 and the fourth tail section 46 slide correspondingly relative to the cap 14 to abut against the first block 20, the second block 22, the third block 24 and the fourth block 26 respectively. At this time, via the first block 20 and the third block 24 blocking deformation of the first plate 28 and the second block 22 and the fourth block 26 blocking deformation of the second plate 30, the abutting part 52 can be surely limited to abut under the first magnetic member 50 when the cap 14 is released. In such a manner, the present invention can efficiently solve the prior art problem that deformation of the plate caused by excessive pressing force dislocates the abutting part to be located above the magnetic member, so as to prevent failure of linkage between the two plates or structural jamming of the two plates for greatly improving operational stability of the keyswitch.
It should be mentioned that the block forming position is not limited to the aforesaid embodiment, which means the present invention could adopt the design that the block is directly formed on the plate in another embodiment. In brief, in another embodiment, the blocks could be formed on the tail sections of the two plates respectively and could be spaced from the cap. In such a manner, if the cap is pressed to cause deformation of the two plates, the tail sections of the two plates slide relative to the cap to make the blocks abut against the cap, so as to generate the same limiting effect as mentioned by the aforesaid embodiment. As for the detailed description for this embodiment and other derived embodiments (e.g. the embodiment that the first and third blocks are formed on the cap and the second and fourth blocks are formed on the second and fourth tail sections of the second plate respectively), it could be reasoned by analogy according to the aforesaid description and omitted herein. In addition, the third block and the fourth block are omissible components, meaning that the present invention could adopt the design in which there are only the first block and the second block formed on the cap to block deformation of the first and second plates for simplifying the structural design of the keyswitch.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Number | Date | Country | Kind |
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106137485 | Oct 2017 | TW | national |