Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CHAIR SEAT SLIDING AND LOCKING MECHANISM
BACKGROUND OF THE INVENTION
100011 The present invention relates to a chair seat sliding and
locking mechanism
and, more particularly, to a mechanism for reliably locking a chair seat in a
desired
position.
[00021 Conventional leisure chairs permitting position adjustment for
sitting and
lying generally include a rod fixed on a base. A locking mechanism is slidably
mounted on the rod and is coupled with a chair seat. The chair seat can be
moved
through adjustment, and the locking mechanism can move along the rod. When the
chair seat reaches a desired position, the locking mechanism and the rod are
fixed to
position the chair seat. The backrest is also moved together with the chair
seat, such
that the sitting angle or lying angle can be adjusted.
100031 Conventional locking mechanisms are generally fixed by turning
a knob to
press against the rod, which is inconvenient and not always reliable in
positioning if the
knob is not rotated to a tightened state. Furthermore, when the knob is turned
loose, the
backrest in a reclined state is liable to recline to its maximum reclining
angle under the
gravitational force, leading to inconvenient adjustment in the angular
position.
100041 In an arrangement to overcome the above disadvantages, a
positioning device
includes a clamping seat, a positioning block, an adjusting rod, and a
coupling
mechanism. The clamping seat can move together with a chair seat and includes
a hole
receiving a fixed rod on the chair seat. The clamping seat further includes
first and
second clamping members movable relative to each other between an open state
and a
clamping state. The positioning block is mounted on the clamping seat. The
adjusting
rod is coupled to a side of the positioning block by the coupling mechanism.
Thus, the
adjusting rod can pivot to move the first and second clamping members to the
open state,
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permitting the chair seat and the clamping seat to slide along the fixed rod.
When the seat
reaches the desired position, the adjusting rod is pivoted to move the first
and second
clamping members to the clamping state, thereby locking the clamping seat and
the chair
seat in place. An example of this arrangement is disclosed in U.S. Patent No.
7,735,925.
[0005] However, the adjusting rod displaces when the chair seat and the
clamping seat
move, such that the hand of a user cannot control the adjusting rod according
to the habitual
position. Furthermore, when the clamping seat is moved to a front position
permitting the
user to lie down, the user may have to get up to grip the adjusting rod that
has moved to the
front position, causing inconvenience in use.
BRIEF SUMMARY OF THE INVENTION
[0006] An aspect of the present invention is to provide a chair seat sliding
and locking
mechanism providing improved operational convenience and improved locking
stability.
According to another aspect of the invention, there is provided 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.
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Date Recue/Date Received 2021-01-26
[0007] A chair seat sliding and locking mechanism according to the present
invention
includes a positioning tube and a sliding seat. The positioning tube is
configured to be
mounted to a rod of a base of a chair having a chair seat. The positioning
tube is rotatable
relative to the rod but is not slidable relative to the rod along a
longitudinal axis of the rod.
The positioning tube includes a positioning portion. The sliding seat includes
a coupling
portion coupled with the chair seat, permitting joint movement of the sliding
seat and the 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 the positioning
portion 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
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engages with the catching portion, the sliding seat is fixed relative to the
positioning
tube.
100081 In an example, the positioning portion protrudes outwards from
an outer
periphery of the positioning tube and extends in an axial direction. The
receiving hole
of the sliding seat includes a recessed portion corresponding to the
positioning portion of
the positioning tube. The catching portion is disposed at a side of the
receiving hole
corresponding to the recessed portion.
100091 Thus, the positioning portion of the positioning tube can be
moved to a
position aligned with the recessed portion of the sliding seat and disengages
from the
catching portion, permitting adjustment of the position of the sliding seat.
On the other
hand, when the positioning portion of the positioning tube engages with the
catching
portion by turning the positioning tube to another position, the position of
the chair seat
is fixed. Accordingly, the operation is simple. The chair seat can be
pivotably
coupled with a backrest, such that the reclining angle of the backrest can be
adjusted
while adjusting the position of the chair seat.
100101 In an example, the positioning portion of the positioning tube
includes a first
toothed portion extending in the axial direction. The first toothed portion
includes a
plurality of first teeth. Each of the plurality of first teeth has a tip
tangent to the
positioning tube. The catching portion of the sliding seat includes a second
toothed
portion engageable with the first toothed portion. The second toothed portion
includes
a plurality of second teeth engageable with the plurality of first teeth.
100111 In an example, the positioning tube includes a handle
extending radially from
an outer side of the positioning tube. The handle can be operated to rotate
the
positioning tube. When the positioning portion engages with the catching
portion, the
first teeth of the first toothed portion engage with the second teeth of the
second toothed
portion, which provides a better positioning effect than conventional
mechanisms by
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friction. Thus, the positions of the sliding seat and the chair seat and the
reclining angle
of the reclining angle can be reliably retained.
[00121 During adjustments where the sliding seat moves between
different positions,
the handle remains in the same position, a user can easily hold the handle
according to
his or her operational habit. Accordingly, the chair seat sliding and locking
mechanism
according to the present invention provides improved locking stability and
improved
operational convenience.
100131 The present invention will become clearer in light of the
following detailed
description of illustrative embodiments of this invention described in
connection with
the drawings.
DESCRIPTION OF THE DRAWINGS
[0014] 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.
[0015] FIG. 2 is an exploded, perspective view of the chair seat
sliding and locking
mechanism of FIG. 1.
100161 FIG. 2A is an enlarged view of a circled portion of FIG. 2.
[0017] FIG. 28 is an enlarged view of another circled portion of FIG.
2.
[0018] 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.
[00191 FIG. 4 is a side view illustrating adjustment of the chair seat of
FIG. 1.
[0020] FIG. 5 is a cross sectional view similar to FIG. 3 with the
chair seat sliding
and locking mechanism in a locked state.
[0021] FIG. 6 is a partially cross-sectioned top view of a portion of
the chair of FIG.
1.
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DETAILED DESCRIPTION OF THE INVENTION
[0022] 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.
[0023] 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.
[0024] 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 422
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
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Date Recue/Date Received 2021-01-26
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 426 having a plurality
of second
teeth 427 engageable with the plurality of first teeth 413 of the first
toothed portion412.
[0025] 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 411 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.
[0026] 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
positioning 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.
[0027] 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
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Date Recue/Date Received 2021-01-26
present invention provides improved locking stability and improved operational
convenience.
[0028] 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.
[0029] 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.
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Date Recue/Date Received 2021-01-26
Number list
1 base
11 supporting board
12 armrest frame
13 rod
2 chair seat
3 backrest frame
4 locking mechanism
41 positioning tube
411 positioning portion
412 first toothed portion
413 first teeth
414 handle
42 sliding seat
421 coupling portion
422 receiving portion
423 receiving hole
424 recessed portion
425 catching portion
426 second toothed portion
427 second teeth
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