The invention relates to a collapsible chair, and more particularly, to a simply operable collapsible chair a backrest portion of which is simply adjustable with a user sitting on a seat portion thereof.
2. DESCRIPTION OF RELATED ART
Collapsible chairs having a foldable frame and a soft panel attached to the frame have long been developed. They are able to be folded for saving storage space. Early collapsible chairs need a relative complex process of folding and expanding. They often require two hands and several steps. Some recent collapsible chairs have been improved and need only one hand and one step of action of user to either fold or expand the chairs. However, backrest adjustment of such simply operable collapsible chairs is still an untackled problem. It is desirable for users a one step operation collapsible chair having an adjustable backrest simply operable when a user is sitting on the chair.
BRIEF SUMMARY OF THE INVENTION
The main object of the invention is to provide a simply operable collapsible chair having an adjustable backrest portion which is simply operable when a user is sitting on a seat portion thereof.
In order to accomplish the above objects, the present invention provides a collapsible chair having a frame and a soft panel attached to the frame. The soft panel has a backrest portion and a seat portion. The frame has a pair of front legs each having an upper end, a pair of joints to each of which the upper end of one of the pair of front legs pivotally linked, a pair of rear legs each having an upper end pivotally linked to one of the joints, a pair of seat bars each pivotally linked to respective front leg with a pin, a pair of sleeves each pivotally linked to one of the two seat bars and each slidably containing one rear leg, a pair of backrest bars each pivotally linked to respective seat bar with a link, a pair of armrest bars each having a rear end pivotally linked to each backrest bar, a pair of front scissoring bars lower ends thereof being respectively pivotally linked to the lower end of each front leg and upper ends thereof being respectively pivotally linked to a front end of each seat bar, a pair of slide blocks each being able to slide along respective backrest bar, a pair of rear scissoring bars lower ends thereof being respectively pivotally linked to a rear end of each seat bar and upper ends thereof being respectively pivotally linked to each slide block, a pair of backrest adjustment devices each having at least one positioning pin securely formed on one joint and one corresponding guiding groove being securely fixed to each armrest bar and having a plurality of notches for accommodating each positioning pin, and a latch having two pivotally linking poles each pivotally linked to one of the two rear scissoring bars.
These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred embodiment of the collapsible chair of the invention.
FIG. 2 is another perspective view of the collapsible chair shown in FIG. 1 with a soft panel thereof being removed for illustration.
FIGS. 3
a through 3c are partially enlarged views thereof.
FIG. 4 is a perspective view of the collapsible chair shown in FIG. 1 showing an operation of an adjustable backrest portion thereof. And,
FIG. 5 is a perspective view of the collapsible chair shown in FIG. 1 showing a folded frame thereof.
DETAILED DESCRIPTION OF THE INVENTION
Shown in FIG. 1 is the preferred embodiment of the collapsible chair of the invention. The collapsible chair has a frame 1 and a soft panel 2 securely attached to the frame 1. The soft panel 2 has a backrest portion 21 and a seat portion 22. Together with reference to FIGS. 2, 3a, 3b and 3c, in which the soft panel 2 is removed for better illustration of the frame 1, the frame 1 has a pair of front legs 10a and 10b each having an upper end, a pair of joints 12a and 12b to each of which the upper end of one of the pair of front legs 10a or 10b pivotally linked, a pair of rear legs 11a and 11b each having an upper end pivotally linked to one of the two joints 12a or 12b, a pair of seat bars 13a and 13b each pivotally linked to respective front leg 10a and 10b with a pin 130a or 130b, a pair of sleeves 131a and 131b each pivotally linked to one of the two seat bars 13a and 13b and each slidably containing one rear leg 11a or 11b, a pair of backrest bars 14a and 14b each pivotally linked to respective seat bar 13a and 13b with a link 140a and 140b, a pair of armrest bars 15a and 15b each having a rear end pivotally linked to each backrest bar 14a or 14b, a pair of front scissoring bars 16a and 16b lower ends thereof being respectively pivotally linked to the lower end of each front leg 10a or 10b and upper ends thereof being respectively pivotally linked to a front end of each seat bar 13a or 13b, a pair of slide blocks 17a and 17b each being able to slide along respective backrest bar 14a or 14b, a pair of rear scissoring bars 18a and 18b lower ends thereof being respectively pivotally linked to a rear end of each seat bar 13a or 13b and upper ends thereof being respectively pivotally linked to each slide block 17a or 17b, a pair of backrest adjustment devices 150a and 150b each having at least one positioning pin 151a or 151b securely formed on one joint 12a or 12b and one corresponding guiding groove 152a or 152b being securely fixed to each armrest bar 15a or 15b and having a plurality of notches 153a or 153b for accommodating each positioning pin 151a or 151b, and a latch 19 having two pivotally linking poles 191 and 192 each pivotally linked to one of the two rear scissoring bars 18a or 18b.
In use, a user is able to expand the collapsible chair by holding one of the two backrest bars 14a or 14b with one hand and shaking up and down one time. The pair of seat bars 13a and 13b will rotate downward round each link 140a and 140b. The pair of front legs 10a and 10b will rotate forward round each pin 130a and 130b. The pair of front scissoring bars 16a and 16b expands and the two seat bars 13a and 13b departure with respect to each other. Then the rear scissoring bars 18a and 18b expand until the linking poles 191 and 192 of the latch 19 are pulled to straight, as shown in FIG. 3. In folding, the user is able to stand behind the collapsible chair and grasp one backrest bar 14a or 14b with one hand. By keeping one rear leg 11a or 11b of the same side with the held backrest bar 14a or 14b in touching ground, the user is able to incline the whole chair backward and the chair will collapse under its own gravity. The folded collapsible chair is as shown in FIG. 6. The user is surely able to fold the chair more efficiently with two hands. As particularly shown in FIG. 3c, the latch 19 may further has at least one protrusion 193 or 194 formed on one of the two linking poles 191 or 192. The protrusion is used to prevent the linking poles 191 or 192 from rotating downward after they have been pulled to straight. In the shown embodiment, the latch 19 has two protrusions 193 or 194 each formed on one linking pole 191 or 192.
Particularly with reference to FIG. 5, the user, while sitting on the seat portion 22, is able to first uplift the pair of armrest bars 15a and 15b making the notch 153a and 153b leave the respective positioning pin 151a and 151b and move the pair of armrest bars 15a and 15b forward or backward. The pair of backrest bars 14a and 14b will rotate round the link 140a and 140b and the slide blocks 17a and 17b will slide along the backrest bars 14a and 14b, respectively. Until the user select a desired position of the backrest portion 21, he is able to press the armrest bars 15a and 15b down making the positioning pin 151a and 151b enter one notch 153a and 153b respectively and the pair of armrest bars 15a and 15b will no longer moveable. The user does not have to stand up during the whole process of the above adjustment.
From above description, it is seen that the objects of the present invention have been fully and effectively accomplished. Embodiment of the invention has been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from the invention's principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.
Patent Application
20120175917
