Keyboard plate tilt control structure

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the keyboard plate structure of a computer desk and more particularly, to a keyboard plate tilt control structure that allows the user to adjust the tilt angle of the keyboard for data entry operation comfortably.

2. Description of the Related Art

A computer desk has a keyboard rack for carrying a keyboard. The keyboard rack comprises a sliding rail assembly, and a keyboard plate mounted on the sliding rail assembly. The keyboard plate can be moved with the sliding rail assembly in and out of the computer desk. The keyboard plate is affixed to the sliding rail assembly in horizontal. Therefore, the user cannot tilt the keyboard plate to support the keyboard in a tilt angle. The user can pull the pivoted foot members of the keyboard to the extended position to support the keyboard on the keyboard plate in a tilt angle. However, this tilt angle does not fit every user. It is uncomfortable to operate a keyboard that is held in horizontal or in a small tilt angle.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a keyboard plate tilt control structure, which enables the user to adjust the keyboard plate to one of a series of tilt angles to support a keyboard in the desired angular position for data entry operation comfortably.

To achieve this and other object of the present invention, the keyboard plate tilt control structure is provided between the bottom side of a keyboard plate and the top side of a sliding rail assembly for controlling the tilt angle of the keyboard plate relative to the sliding rail assembly, comprising: a crank transversely coupled to the sliding rail assembly and movable in transverse direction relative to the sliding rail assembly within a distance and rotatable relative to the sliding rail assembly, the crank having a first crank element disposed in contact with the bottom side of the keyboard plate and adapted to tilt the keyboard plate upon rotation of the crank by the user; a coupling frame fixedly mounted in the bottom side of the keyboard plate, the coupling frame comprising a sliding slot coupled to the first crank element of the crank; and a crank lock adapted to stop the crank from rotary motion, the crank lock comprising an index plate fixedly fastened to the sliding rail assembly, the index plate having a plurality of locating holes spaced around the crank, and a finger fixedly provided at the first crank element for selectively engaging one of the locating holes of the index plate to stop the crank from rotary motion relative to the sliding rail assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the preferred embodiment of the present invention.

FIG. 2 is an assembly view in an enlarged scale of the preferred embodiment of the present invention.

FIG. 3A is a plain view of a part of the present invention, showing the crank locked.

FIG. 3B is similar to FIG. 3A but showing the crank unlocked.

FIG. 4A is a schematic side view of the preferred embodiment of the present invention, showing the keyboard plate supported in a tilt position.

FIG. 4B is similar to FIG. 4A but showing the tilt angle of the keyboard plate adjusted.

FIG. 4C is similar to FIG. 4B but showing the tilt angle of the keyboard plate adjusted.

FIG. 4D is similar to FIG. 4C but showing the tilt angle of the keyboard plate zeroed and the keyboard plate lock locked.

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, a keyboard plate tilt control structure is provided between a sliding rail assembly 10 and a keyboard plate 100 for controlling the tilt angle of the keyboard plate 100, comprising a crank 20, a coupling frame 30, a crank lock 40, a keyboard plate tilter 50, and a keyboard plate lock 60.

The crank 20 is pivoted to the sliding rail assembly 10, having a first crank element 21 suspending above the sliding rail assembly 10, a second crank element 22 connected to one end of the first crank element 21 and extended out of one lateral side of the sliding rail assembly 10, and a grip 23 connected to one end of the second crank element 21 remote from the first crank element 21. The design of the second crank element 22 enables the moving direction and angle of the first crank element 21 to be in conformity with the grip 23 when the user operates the grip 23 to rotate the crank 20.

The coupling frame 30 is fixedly fastened to the bottom side of the keyboard plate 100, having two parallel sliding slots 31 that extend in direction toward the front side 101 of the keyboard plate 100 and are coupled to the first crank element 21 of the crank 20.

The crank lock 40 comprises an index plate 41 fixedly fastened to the sliding rail assembly 10 at one lateral side in a vertical position and having a plurality of locating holes 43 formed in the index plate 41 and spaced around the pivot point between the crank 20 and the sliding rail assembly 10, and a finger 42 fixedly connected to the first crank element 21 of the crank 20 and aimed at the index plate 41. Actually, the crank 20 is pivoted to the index plate 41.

The keyboard plate tilter 50 comprises an axle 51 transversely provided at the front side of the sliding rail assembly 10, two lugs 53 fixedly fastened to the bottom side of the keyboard plate 100 and respectively pivoted to the two distal ends of the transverse axle 51, and torsional springs 52 adapted to support the keyboard plate 100 on the sliding rail assembly 10 in a tilt position. The torsional springs 52 are mounted on the transverse axle 51, each having one end 521 stopped at the top side of the sliding rail assembly 10 and the other end 522 stopped against the bottom side of the keyboard plate 100.

The keyboard plate lock 60 comprises a female locking member, for example, a retaining hole 61 formed in the top side of the sliding rail assembly and spaced from the axle 51 at a distance, and a male locking member, for example, a retaining bolt 62 fixedly provided at the bottom side of the keyboard plate 100 and spaced from the coupling frame 30 at one side opposite to the lugs 53.

Referring to FIG. 1 again, the index plate 41 has a pivot hole 411 in axial alignment with a barrel 412 at the sliding rail assembly 10. The index plate 41 and the barrel 412 are bilaterally disposed at the top side of the sliding rail assembly 10 and aligned in a line. The first crank element 21 has a first end pivotally coupled to the barrel 412 and a second end pivotally coupled to the pivot hole 411. The second crank element 22 has one end fixedly axially connected to the second end of the first crank element 21 and the other end fixedly mounted with the grip 23.

Referring to FIGS. 3A and 3B, the crank 20 can be moved in transverse direction across the sliding rail assembly 10 relative to the barrel 412 and the index plate 41 within a distance L between a first position, namely, the locking position where the finger 42 is engaged into one locating hole 43 of the index plate 41 to stop the crank 20 from rotation relative to the index plate 41 (see FIG. 3A), and a second position, namely, the unlocking position where the finger 42 is disengaged from the locating holes 43 of the index plate 41 and the crank 20 can be rotated relative to the index plate 41.

Referring to FIG. 4A and FIG. 2 again, the first crank element 21 is coupled to the sliding slots 31 of the coupling frame 30, and the torsional springs 52 impart an upward pressure to the keyboard plate 100 relative to the sliding rail assembly 10, and therefore, the keyboard plate tilter 50 steadily supports the keyboard plate 100 on the sliding rail assembly 10 in a tilt angle.

Referring to FIGS. 4A-4C and FIGS. 3A and 3B again, the user can move the crank 20 in transverse direction across the sliding rail assembly 10 from the locking position to the unlocking position to disengage the finger 42 from the locating holes 43 of the index plate 41 and then turn the crank 20 to shift the finger 42 from one locating hole 43 to another to adjust the tilt angle of the keyboard plate 100 relative to the sliding rail assembly 10. When adjusted, the crank 20 is pulled backwards to engage the finger 42 into the corresponding locating hole 43. According to the present preferred embodiment, the index plate 41 has three locating holes 43 spaced around the pivot hole 411 at different angles.

Referring to FIG. 5 and FIG. 4D, the user can move the crank 20 in transverse direction across the sliding rail assembly 10 from the locking position to the unlocking position to disengage the finger 42 from the locating holes 43 of the index plate 41 and then turn the crank 20 to the position where the first crank element 21 is maintained in parallel to the sliding rail assembly 10. At this time, the user can press the keyboard plate 100 to force the retaining bolt 62 into engagement with the retaining hole 61, and therefore the keyboard plate 100 is locked to the sliding rail assembly 10 in a horizontal position so that the user can push the keyboard plate 100 and the sliding rail assembly 10 back to the inside of the computer desk (not shown).

A prototype of keyboard plate tilt control structure has been constructed with the features of FIGS. 1-5. The keyboard plate tilt control structure functions smoothly to provide all of the features discussed earlier.

Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.