Keyboard plate tilt control structure

Abstract

A keyboard plate tilt control structure provided between a keyboard plate and a sliding rail assembly for controlling the tilt angle of the keyboard plate is disclosed to include a crank pivoted to the sliding rail assembly for rotation by the user to adjust the tilt angle of the keyboard plate, a coupling frame fixedly mounted on the bottom side of the keyboard plate and coupled to the crank through a slip joint, a crank lock for locking the crank, and a keyboard plate lock for locking the keyboard plate in horizontal.

1 . A keyboard plate tilt control structure provided between the bottom side of a keyboard plate and the top side of a sliding rail assembly for controlling the tilt angle of said keyboard plate relative to said sliding rail assembly, the keyboard plate tilt control structure comprising: 
 a crank transversely coupled to said sliding rail assembly and movable in transverse direction relative to said sliding rail assembly within a distance and rotatable relative to said sliding rail assembly, said crank having a first crank element disposed in contact with the bottom side of said keyboard plate and adapted to tilt said keyboard plate upon rotation of said crank by the user;    a coupling frame fixedly mounted in the bottom side of said keyboard plate, said coupling frame comprising a sliding slot coupled to said first crank element of said crank; and    a crank lock adapted to stop said crank from rotary motion, said crank lock comprising an index plate fixedly fastened to said sliding rail assembly, said index plate having a plurality of locating holes spaced around said crank, and a finger fixedly provided at said first crank element for selectively engaging one of the locating holes of said index plate to stop said crank from rotary motion relative to said sliding rail assembly.    
     
     
         2 . The keyboard plate tilt control structure as claimed in  claim 1 , further comprising spring means connected between said keyboard plate and said sliding rail assembly to support said keyboard plate on said sliding rail assembly in a tilt angle.  
     
     
         3 . The keyboard plate tilt control structure as claimed in  claim 2 , wherein said spring means comprises a plurality of metal spring members.  
     
     
         4 . The keyboard plate tilt control structure as claimed in  claim 3 , wherein said metal spring members are torsional springs.  
     
     
         5 . The keyboard plate tilt control structure as claimed in  claim 4 , wherein said torsional springs are mounted on a transverse axle at a front side of said sliding rail assembly, each having a first end stopped against said sliding rail assembly and a second end stopped against the bottom side of said keyboard plate.  
     
     
         6 . The keyboard plate tilt control structure as claimed in  claim 2 , further comprising a keyboard plate lock adapted to lock said keyboard plate in a horizontal position in parallel to said sliding rail assembly.  
     
     
         7 . The keyboard plate tilt control structure as claimed in  claim 6 , wherein said keyboard plate lock comprises a retaining hole formed in said sliding rail assembly, and a retaining bolt fixedly provided at the bottom side of said keyboard plate for engaging said retaining hole when said keyboard plate is turned to horizontal.  
     
     
         8 . The keyboard plate tilt control structure as claimed in  claim 1 , wherein said crank has a grip at one end thereof.  
     
     
         9 . The keyboard plate tilt control structure as claimed in  claim 8 , wherein said crank further comprises a second crank element connected between said first crank element and said grip.  
     
     
         10 . The keyboard plate tilt control structure as claimed in  claim 9 , wherein said first crank element and said second crank element curve in same direction.