Chairs and seats – Collapsible chair; i.e. – relatively folding bottom – back,... – Back and legs collapse independently
Reexamination Certificate
2000-11-02
2001-07-03
Brown, Peter R. (Department: 3636)
Chairs and seats
Collapsible chair; i.e., relatively folding bottom, back,...
Back and legs collapse independently
C248S440000, C297S016100, C108S125000
Reexamination Certificate
active
06254177
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a foldable chair frame, more particularly to a foldable chair frame provided with a locking unit for locking the chair frame at an unfolded state so as to prevent untimely folding of the chair frame.
2. Description of the Related Art
FIG. 1
shows a conventional chair frame
1
which includes a generally horizontal seat member
11
, a front leg member
13
with an upper end pivoted to a front portion of the seat member
11
by means of a front pivot axle
12
, and a rear leg member
14
with an upper end pivoted to a rear portion of the seat member
11
by means of a rear pivot axle
12
′. A front linking unit
15
and a rear linking unit
15
′ are disposed between the front and rear leg members
13
,
14
for connecting foldably the front and rear leg members
13
,
14
to the seat member
11
such that the front leg member
13
is foldable rearwardly toward the seat member
11
and such that the rear leg member
14
is foldable forwardly toward the seat member
11
. As shown in
FIG. 2
, each of the front and rear linking units
15
,
15
′ includes a first linking plate
151
having an upper end pivoted to the seat member
11
by means of a horizontal first pivot pin
154
, and a second linking plate
152
having an upper end pivoted to a lower end of the first linking plate
151
by means of a horizontal second pivot pin
153
and a lower end pivoted to an intermediate section of a respective one of the front and rear leg members
13
,
14
by means of a horizontal third pivot pin
154
′. The lower end of the first linking plate
151
is formed with a stop projection
155
for engaging an engaging groove
156
formed in the upper end of the lower linking plate
152
so as to limit further pivoting movement between the first and second linking plates
151
,
152
when the first and second linking plates
151
,
152
are unfolded from each other (see FIG.
1
). By unfolding the first and second linking plates
151
,
152
from each other, the respective one of the front and rear leg members
13
,
14
can be unfolded from the seat member
11
. To fold the chair frame
1
, the juncture portions of the first and second linking plates
151
,
152
are pushed upwardly to disengage the stop projection
155
from the engaging groove
156
and to result inpivoting movement of the first and second linking plates
151
,
152
relative to each other, thereby folding the front or rear leg member
13
,
14
toward the seat member
11
.
However, since the first and second linking plates
151
,
152
are not locked to each other at the unfolded state, it is likely that the front and rear leg members
13
,
14
might be untimely folded toward the seat member
11
. This could happen when the chair frame
1
is disposed on an uneven ground surface, such as on the beach. As such, user safety cannot be ensured.
SUMMARY OF THE INVENTION
Therefore, the main object of the present invention is to provide a foldable chair frame having a locking unit for locking the chair frame at an unfolded state to prevent untimely folding of the same.
Accordingly, the foldable chair frame of the present invention includes a generally horizontal seat member, front and rear leg members, and front and rear linking units. The front leg member has an upper end pivoted to the seat member at a horizontal front pivot axis, a lower end adapted to be supported on a ground surface, and an intermediate portion between the upper and lower ends. The front leg member is foldable rearwardly toward the seat member about the front pivot axis. The rear leg member is disposed rearwardly of the front leg member, and has an upper end pivoted to the seat member at a horizontal rear pivot axis parallel to the first pivot axis, a lower end adapted to be supported on a ground surface, and an intermediate portion between the upper and lower ends of the rear leg member. The rear leg member is foldable forwardly toward the seat member about the rear pivot axis. The front and rear linking units are disposed between the front and rear leg members. Each of the front and rear linking units includes first and second linking plates, a resilient locking plate, and a locking pin. The first linking plate has an upper end pivoted to the seat frame, and a lower end formed with a first pivot hole. The second linking plate has an upper end formed with a second pivot hole aligned with the first pivot hole, and a lower end pivoted to the intermediate portion of a respective one of the front and rear leg members. The locking plate has a pivoting end portion pivoted to the seat member and the upper end of a respective one of the front and rear leg members at a respective one of the front and rear pivot axes, an operating end portion opposite to the pivoting end portion, and an inclined section between the pivoting end portion and the operating end portion and formed with an elongated hole that has an enlarged hole end proximate to the operating end portion. The inclined section is inclined relative to the pivoting end portion and the operating end portion so as to dispose the pivoting end portion and the operating end portion in different vertical planes. The locking pin extends through the elongated hole in the locking plate and through the first and second pivot holes in the first and second linking plates for interconnecting foldably the first and second linking plates. The locking pin has a thinner pin section slidable along the elongated slot and a wider pin section for engaging the enlarged hole end of the elongated hole. The locking pin is movable in the elongated hole so as to engage the wider pin section of the locking pin with the enlarged hole end of the elongated hole when the respective one of the front and rear leg members is unfolded from the seat member, thereby positioning the first and second linking plates at an unfolded state relative to each other, and thereby positioning the respective one of the front and rear leg members at an unfolded state relative to the seat member. The operating end portion of the locking plate is operable to align the enlarged hole end of the elongated hole with the narrower pin section of the locking pin so as to disengage the wider pin section from the enlarged hole end and to permit movement of the locking pin along the elongated hole for folding the first and second linking plates toward each other, thereby folding the respective one of the front and rear leg members toward the seat member.
REFERENCES:
patent: 897737 (1908-09-01), Goodrich
patent: 2011251 (1935-08-01), Michelson
patent: 3464373 (1969-09-01), Larson
patent: 762820 (1934-04-01), None
Brown Peter R.
Ladas & Parry
Shin Yeh Enterprise Co., Ltd.
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