Chair seat sliding and locking mechanism

Abstract

A chair seat sliding and locking mechanism includes a positioning tube and a sliding seat. The positioning tube is mounted to a rod of a chair base. The positioning tube is rotatable relative to the rod but is not longitudinally slidable. The sliding seat includes a coupling portion securely coupled with a chair seat. The coupling portion includes a receiving portion having a receiving hole with a catching portion. The positioning tube is received in the receiving hole. When the positioning tube is rotated relative to the rod to a first position in which a positioning portion of the positioning tube disengages from the catching portion, the sliding seat is movable along the positioning tube. When the positioning tube is rotated relative to the rod to a second position in which the positioning portion engages with the catching portion, the sliding seat is fixed relative to the positioning tube.

Claims

1. A chair seat sliding and locking mechanism comprising: a positioning tube configured to be mounted to a rod of a base of a chair having a chair seat, wherein the positioning tube is rotatable relative to the rod but is not slidable relative to the rod along a longitudinal axis of the rod, and wherein the positioning tube includes a positioning portion; a sliding seat including a coupling portion coupled with the chair seat, permitting joint movement of the sliding seat and the chair seat, wherein the coupling portion includes a receiving portion having a receiving hole with a catching portion, wherein the positioning tube is received in the receiving hole, wherein when the positioning tube is rotated relative to the rod to a first position in which the positioning portion disengages from the catching portion, the sliding seat is movable along the positioning tube, and wherein when the positioning tube is rotated relative to the rod to a second position in which the positioning portion engages with the catching portion, the sliding seat is fixed relative to the positioning tube.

2. The chair seat sliding and locking mechanism as claimed in claim 1, wherein the positioning portion protrudes outwards from an outer periphery of the positioning tube and extends in an axial direction, and wherein the receiving hole of the sliding seat includes a recessed portion corresponding to the positioning portion of the positioning tube.

3. The chair seat sliding and locking mechanism as claimed in claim 2, wherein the catching portion is disposed at a side of the receiving hole corresponding to the recessed portion.

4. The chair seat sliding and locking mechanism as claimed in claim 3, wherein the positioning portion of the positioning tube includes a first toothed portion extending in the axial direction, wherein the catching portion of the sliding seat includes a second toothed portion engageable with the first toothed portion.

5. The chair seat sliding and locking mechanism as claimed in claim 4, wherein the first toothed portion includes a plurality of first teeth, wherein each of the plurality of first teeth has a tip tangent to the positioning tube, and wherein the second toothed portion includes a plurality of second teeth engageable with the plurality of first teeth.

6. The chair seat sliding and locking mechanism as claimed in claim 1, wherein the positioning tube includes a handle extending radially from an outer side of the positioning tube.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a chair including a chair seat sliding and locking mechanism of an embodiment according to the present invention.

(2) FIG. 2 is an exploded, perspective view of the chair seat sliding and locking mechanism of FIG. 1.

(3) FIG. 2A is an enlarged view of a circled portion of FIG. 2.

(4) FIG. 2B is an enlarged view of another circled portion of FIG. 2.

(5) FIG. 3 is a cross sectional view of a portion of the chair of FIG. 1 with the chair seat sliding and locking mechanism in an unlocked state.

(6) FIG. 4 is a side view illustrating adjustment of the chair seat of FIG. 1.

(7) FIG. 5 is a cross sectional view similar to FIG. 3 with the chair seat sliding and locking mechanism in a locked state.

(8) FIG. 6 is a partially cross-sectioned top view of a portion of the chair of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(9) FIGS. 1-3 show a chair including a chair seat sliding and locking mechanism 4 of an embodiment according to the present invention. The chair includes a base 1, a chair seat 2, a backrest frame 3, and the chair seat sliding and locking mechanism 4. The base 1 includes two upright supporting boards 11 opposite to each other. Two armrest frames 12 are disposed on tops of the two upright supporting boards 11, respectively. A rod 13 is mounted between each of the two upright supporting boards 11 and an associated armrest frame 12. The backrest frame 3 is pivotably connected to the two armrest frames 12 and the chair seat 2. The backrest frame 3 can move relative to the seat 2 to change a reclining angle.

(10) The chair seat sliding and locking mechanism 4 is mounted on at least one of the rods 13 and includes a positioning tube 41 and a sliding seat 42. The positioning tube 41 is mounted around and rotatable relative to the rod 13 but is not slidable relative to the rod 13 along a longitudinal axis of the rod 13. The positioning tube 41 includes a positioning portion 411 protruding outwards from an outer periphery of the positioning tube 41 and extending in an axial direction. The positioning portion 411 of the positioning tube 41 includes a first toothed portion 412 extending in the axial direction. The first toothed portion 412 includes a plurality of first teeth 413 arranged consecutively in the axial direction. Each of the plurality of first teeth 413 has a tip tangent to the positioning tube 41. A handle 414 extends radially from an outer side of the positioning tube 41.

(11) The sliding seat 42 includes a side having a coupling portion 421 coupled with the chair seat 2, permitting joint movement of the sliding seat 42 and the chair seat 2. The coupling portion 421 includes a side including a receiving portion 411 having a receiving hole 423. The positioning tube 41 is received in the receiving hole 423. The receiving hole 423 of the sliding seat 42 includes a recessed portion 424 corresponding to the positioning portion 411 of the positioning tube 41. The recessed portion 424 includes a side having a catching portion 425 preferably made of an anti-sliding material and located corresponding to the recessed portion 424. The catching portion 425 includes a second toothed portion 425 having a plurality of second teeth 427 engageable with the plurality of first teeth 413 of the first toothed portion 426. 427.

(12) When the positioning tube 41 is rotated relative to the rod 13 to a first position shown in FIGS. 3 and 4 through operation of the handle 414, the positioning portion 411 of the positioning tube 41 is aligned with the recessed portion 424 of the sliding seat 42, and the positioning portion 421 disengages from the catching portion 425. Thus, the sliding seat 42 can move along the positioning tube 41 to adjust the position of the sliding seat 42 and the reclining angle of the backrest frame 3.

(13) After adjustment, the handle 414 can be operated to rotate the positioning tube 41 relative to the rod 13 to a second position (see FIGS. 5 and 6), such that the recessed portion 411 engages with the catching portion 425. Specifically, the first teeth 413 of the first toothed portion 412 engage with the second teeth 427 of the second toothed portion 426, which provides a better positioning effect than conventional mechanisms by friction. Thus, the positions of the sliding seat 42 and the chair seat 2 and the reclining angle of the reclining angle 3 can be reliably retained.

(14) During adjustments where the sliding seat 42 moves between different positions, the handle 414 remains in the same position, a user can easily hold the handle 414 according to his or her operational habit. In this embodiment, the handle 414 is adjacent to the backrest frame 3. Thus, when the backrest 3 is in a larger reclining angle, the user can still reach the handle 414 for operation, providing convenient operation. Accordingly, the chair seat sliding and locking mechanism according to the present invention provides improved locking stability and improved operational convenience.

(15) In a case that the positioning tube 41 does not include the first toothed portion 412 and the sliding seat 42 does not include the second toothed portion 426, the positioning portion 411 and the catching portion 425 can still be locked by friction while permitting easy operation of the handle 414.

(16) Although specific embodiments have been illustrated and described, numerous modifications and variations are still possible without departing from the scope of the invention. The scope of the invention is limited by the accompanying claims.