Bridge structure for keyboards

An improved bridge structure for a keyboard comprising a first linkage element and a second linkage element pivotally engaging with the first linkage element and being located between a base of the keyboard and a key cap and having an elastic element located in the first linkage element for supporting up and down movements of the key cap, wherein:

• the first linkage element has two first arms each having a first pivotal connecting section which includes a first pivotal trough and a first axle, the first pivotal trough having a first trough slant surface section on a bottom thereof, the first axle having a first axle slant surface section on a bottom thereof, the first trough slant surface section and the first axle slant surface section being intersected on a juncture to form a first fulcrum;
• the second linkage element has two second arms each having a second pivotal connecting section which includes a second pivotal trough and a second axle, the second pivotal trough having a second trough slant surface section on a bottom thereof, the second axle having a second axle slant surface section on a bottom thereof, the second trough slant surface section and the second axle slant surface section being intersected on a juncture to form a second fulcrum;
• wherein when the elastic element lifts the key cap the first and the second fulcrum remain stationary at a center point to serve as a circle center of movements such that moving tolerances remain unchanged without increasing when the key cap is depressed downwards, the movements being performed based on the stationary center point which supports and transfers forces in sideward directions to reduce sideward inclination and shaking.