Patent Application
20060037851
1. Field of the Invention
The present invention relates to a miniature side push switch (e.g. 1-3 mm high side push switch), and particularly to a miniature switch used in consumer electronic applications.
2. Description of the Prior Art
The personal electronic consumer productions such as cell phones are designed to comply with a miniature trend as the customers require. Correspondingly, electronic elements such as switches employed in those productions are required to be miniature.
A conventional switch is disclosed in U.S. patent application publication number 2004/0238341. The switch comprises a housing, a plurality of electrical contacts mounted in the housing, a contact plate mounted on the housing for establishing electrical connections between the electrical contacts, a dome disposing on the contact plate for pushing the contact plate against the electrical contacts, a rigid lever positioning on the dome for snap down the dome to actuate the contact blade, and an actuator for driving the rigid lever actuate the dome. The rigid lever has a T-shaped configuration and is formed with a laterally extended rear branch. A central branch rearwardly extends from the rear branch and forms a cam follower upper surface at an upper surface of a free end thereof. A pair of trunnions is respectively formed at opposite ends of the rear branch. The trunnions engage with the housing, so that the rigid is pivotal on an axis of the rear branch. The actuator comprises a rear actuating face at rear end and a ramp at front end. The ramp of the actuator engages with cam follower upper surface. When an external force exerts on the actuator, the actuator is pushed forwardly, the ramp abuts against the cam follower upper surface, and thus the ramp transfers the force downwardly thereby depressing the cam follower downwardly. The rigid lever is pressed to pivot and depress the dome that causes the contact plate contacting the electrical contacts in turn.
Though the conventional switch works well, there's some problem it can not solve. To ensure reliable connections, the force transfer member such as the actuator, the lever and the dome are regarded as essentials of the switch. The rigid lever is molded of plastic material, which can avoid deflection and ensure well performance when it depresses the dome. However, as the switch is so mini in size, every part in the switch is very small, a rigid lever made of plastic may easily be scratched, which effects the lifetime of the switch.
Hence, an improved switch is required to overcome the disadvantages of the prior art.
An object of the present invention is to provide a side push switch with an improved resilient lever.
A side push switch in according with the present invention comprises an insulative housing, a periphery contact and a central contact, a dome, a lever and an actuator mounted on the lever. The contacts are received in the housing by insert molding and respectively form with a first terminal and a second terminal extending out the housing, of which the central contact keeps electrically isolated from the periphery contact in normal status. The dome is disposed over the central contact and electrically connects with the periphery contact. The lever is made of metal material and is formed with a transversal branch and a longitudinal branch laterally extending from the transversal branch. A pair of trunnions are respectively formed at opposite ends of the transversal branch. A depressing portion is formed on the longitudinal branch. An actuating follower is formed at a free end of the longitudinal branch. The actuator has a ramp engaging with the actuating follower of the lever thereby causing the lever depressing the dome to connect the periphery contact and the central contact.
The lever of the switch is made of metal material, and it's endurable avoiding the lever being scratched.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings.
Referring to
The insulative housing 1 is substantially a rectangular case and is formed with a base 11. A pair of U-shaped side walls 13 and 14 upwardly raise from opposite longitudinal side ends of the base 11 and forms an operating cutout 15 and a rear cutout 17. A pair of slits 141 are respectively defined at the longitudinal ends near the bottom surface of the base 11. A cavity 110 is defined on an upper surface of the base 11. A pair of raised stages 111 are formed at the side of the cavity 110 and respectively adjacent to the corresponding U-shaped side walls 13 and 14, which also adjacent to the operating cutout 15. Each stage 111 forms a recess 112 at a bottom portion thereof. A plurality of projections 16 are formed on outer surfaces of the U-shaped side walls 13, 14. A pair of posts 113 project downwardly from a lower surface of the base 11.
The contacts 2 are mounted in the housing 1 by insert molding and include a periphery contact 22 and a central contact 25. The central contact 25 is mounted at the central of the base 11. The periphery contact 22 includes a pair of contacting portion (not labeled) arranged at sides of the central contact 25. A pair of first and second terminals 23 and 26 are respectively and laterally extended from the periphery contact 22 and the central contact 26.
The dome 3 is a dome-liked resilient metal plate. The dome 3 comprises an apex 31 and a contacting blade 32. When an external force exerts on the apex 31, the dome 3 is capable of converting to be reversed.
The lever 5 is made of metal material and is formed with a transverse branch 51. A pair of trunnions 510 are respectively formed at opposite ends of the transverse branch 51. A longitudinal branch 52 extends perpendicularly from a middle portion of the transverse branch 51. The longitudinal branch 52 includes a semi-spheral shaped depressing portion 520 formed at a central portion thereof and an actuating follower 521 formed by bending up a free end thereof.
As a matter of fact, the lever 5 can also be made of other resilient material. The trunnions 510 can be instead by other structures such as clasps and so on, of which the clasps fixed with the housing 1, and the lever 5 can be pressed down for its resilience.
The actuator 4 has an operating branch 42, a pair of mounting branches 43 forwardly and laterally extending from the operating branch 42 and a central branch 44 forwardly extending from the operating branch 42 between the mounting branches 43. A ramp 45 is formed at a free end of the central branch 44, which has a same gradient corresponding to the actuating follower 521.
The cover 6 has a plan plate 61 and a plurality of tabs 62 and 63 downwardly extending from the plan plate 61. A plurality of engaging holes 620 is defined at the tabs 62 for engaging with the projections 16. The tab 63 are used for engaging with the rear cutout 17 opposite to the operating cutout 15 which are both defined by the U-shaped side walls 13 and 14.
Referring to
In operation, an external force is exerted on the operating branch 42. The actuator 4 is pressed forward and the ramp 45 engages with the actuating follower 521 of the lever 5 thereby transferring the force from a forward direction to downward direction. Thus, the lever 5 presses the dome 3 and causes the apex 31 of dome 3 deflected to contact with the uncommon contact 25. So, an electrical connection between the periphery contact 22 and the central contact 25 is established. When the external force is removed, the dome 3 restores itself to a normal status and the connection between the dome 3 and the central contact 25 is broken. The lever 5 is upwardly pushed by the dome 3. The lever 5 pivots around the trunnions 510 thereby the actuating follower 521 pressing the ramp 45 of the actuator 4 and the switch restore itself to the normal status.
It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not be limited to the details given herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200420078890X | Aug 2004 | CN | national |
