Structure of Built-Up Chair

The present invention relates to built-up chairs and relates more particularly to a built-up chair which is easy to assembly and strong in structure.

According to conventional manufacturing process, a chair is generally comprised of a plurality of parts which are connected together by tongue-and-groove or mortise-and-tenon joint and then firmly secured in shape by fastening screws. This processing process is generally completed at factory and not detachable. Disadvantages of the conventional structure of chairs are numerous and outlined hereinafter.

1. Because it is factory made, it occupies much space in delivery and storage;

2. It is not strong in structure after assembly and the connecting parts may be disconnected from place easily to affect its service life;

3. It is not detachable;

4. Because the connecting parts may disconnect from place easily, product design is limited; and

5. The back support or the seat can not be adjusted to best fit individual body size or, if the seat is adjustable the cost will be very expensive.

According to the present invention, there is provided a built-up chair which comprises two stands connected together by a connecting bar, two pairs of supports respectively mounted on said two stands at the top, two side bars respectively mounted on said two pairs of supports and connected together by two cross bars for holding a seat through sliding joint, and a back support connected between said two pairs of supports at the top. The two pairs of supports have each a plurality of parallel grooves convenient for alignment of the two side bars during level position adjusting process. The back support has two rows of holes alternatively aligned with the bolt holes and the through-holes on either pair of the supports for fastening by screws and for convenient position change.

FIG. 1 is a perspective view of the preferred embodiment of the built-up chair of the present invention;

FIG. 2 is an exploded perspective view of thereof;

FIG. 3 is a partly perspective and enlarged view of the front piece which is disposed at the front in each pair of supports;

FIG. 4 is a partly perspective and enlarged view of the connecting bar and the connectors therein;

FIG. 5 is a sectional view taken along line 5--5 on FIG. 1, illustrating the connection of the guide rods of the seat in the channels of the side bars;

FIG. 6 is a partly perspective and enlarged view of the cross bar and the connector therein;

FIG. 7 is a partly sectional view of the stand with the connecting bar;

FIGS. 8 and 9 sectional views showing the procedure in fastening the connecting bolt in the connector; and

FIG. 10 is a sectional view taken along line 10--10 on FIG. 1, illustrating the connection of the back support with the two pairs of supports.

Referring to FIG. 1, a built-up chair in accordance with the present invention is generally comprised of two stands 1 connected together by a connecting bar 2, two pairs of supports 3 and 3' respectively mounted on said two stands 1 at the top, two side bars 5 respectively mounted on said two pairs of supports 3 and 3' and connected together by two cross bars 4 for holding a seat 6, and a back support 7 connected between said two pairs of supports 3 and 3' at the top.

As shown in FIG. 2, each stand 1 has two small holes 11 and 12 on one side with a bush 13 each respectively fastened therein for holding a connecting bolt 14 each, which connecting bolt 14 has a flange 141 at one end exposed to the outside, and two fastening holes 15 obliquely made on the top. As indicated, the connecting bar 2 has two opposite ends respectively connected to the two stands 1. On each connecting end of the connecting bar 2, as shown in FIG. 4, there are two blind holes 21 vertically made at the bottom with a connector 23 each respectively fastened therein, and two through-holes 22 transversely made at the outer edge thereof in communicating with said blind holes 21 respectively. The connector 23 which has a groove 232 on the periphery thereof in communication with the wedge-shaped hole 231 defined therein is provided to match with the connecting bolt 14 for connecting the connecting bar 2 to the stands 1. The two pairs of supports 3 and 3' are respectively fastened in two fastening holes 15 on the stands 1, having each a plurality of parallel grooves 31 or 31' transversely made at the middle. In each pair of supports 3 and 3', as shown in FIG. 3, the front piece 3 which is disposed at the front has two spaced bolt holes 32 and 33 at near the top end thereof and, the back piece 3' which is disposed at the back has two through-holes 32' and 33'. Referring to FIG. 6, similar to the connecting bar 2, the two opposite ends of each cross bar 4 has a blind hole 41 vertically made at the bottom with a connector 23 fastened therein, and a through-hole 42 transversely made on the outer edge thereof in communicating with the blind hole 41. Referring to FIG. 2 again, each side bar 5 has two opposite small holes 51 and 52 at one side with a bush 13 each respectively fastened therein for holding a connecting bolt 14 each, an elongated channel 53 disposed above said small holes 51 and 52 which has one closed and one end opened for fastening the seat 6 through sliding joint, two through-holes 54 a the top for inserting either pair of supports 3 and 3'. The seat 6 has a curved bearing surface 61 orthopedically engineered at the top to comfort sitting, two guide rods 62 at two opposite sides. Referring to FIG. 5, by inserting the two guide rods 62 into the channel 53 of the two side bars 5, the seat 6 is fastened in the two side bars 5 and supported by the two cross bars 4. Referring to FIGS. 1 and 2 again, the back support 2 is orthopedically engineered to fit human's back, having two rows of holes 71 at two opposite ends for fastening in between the two pairs of supports 3 and 3' at the top by screws 36 and 37.

To assemble the aforesaid parts into a chair is easy and outlined hereinafter. Insert the flange 141 of every connecting bolt 14 of the stands 1 through the through-hole 22 and the blind hole 21 on either end of the connecting bar 2 into the connector 23 therein, as shown in FIGS. 7, 8 and 9, and then rotate the connector 23 through a suitable angle relative to the connecting bolt 14 permitting the flange 141 of the connecting bolt 14 to be firmly retained in the wedge- shaped hole 232. Thus, the stands 1 are bilaterally connected to the connecting bar 2 at two opposite ends. Through the same process, the two side bars 5 are bilaterally connected to the two cross bars 4 at two opposite ends. Then, the two pairs of supports 3 and 3' are respectively fastened in the fastening holes 15 of the two stands 1. After the two pairs of supports 3 and 3' are respectively fastened in the two stands 1, the two side bars 5 with the connected two cross bars 4 are mounted on the two pairs of supports 3 and 3' by inserting the two pairs of supports 3 and 3' through the through-holes 54 of the two side bars 5 respectively, permitting the two side bars 5 to be allocated at the parallel grooves 31 or 31' with the channels 53 thereof disposed in alignment with either one of the parallel grooves 31 or 31'. By alternatively aligning the channels 53 with the parallel grooves 31 and 31', the two side bars 5 can be conveniently adjusted to a desired level position. As soon as the two side bars 5 with the two cross bars 4 are mounted on the two pairs of supports 3 and 3', the seat 6 is fastened in the two side bars 5 and supported by the two cross bars 4 by inserting the two guide rods 62 of the seat 6 into the channels 53 of the side bars 5. After the seat 6 having been fastened in place, the back support 7 is inserted in between the two pairs of supports 3 and 3' permitting the bolt holes 32 and 33 and the through-holes 32' and 33' of the two pairs of supports 3 and 3' to be respectively aligned with either pair of the two rows of holes 71 for fastening two screws 36 and 37 to firmly secure the back support 7 in position. By alternatively aligning the two rows of holes 71 with the bolt holes 32 and 33 and the through- holes 32' and 33', the position of the back support 7 on the two pairs of supports 3 and 3' can be conveniently adjusted.

According to foregoing statement, the present invention is to provide such a built-up chair which provides various advantages including the followings:

1. It is easy to assemble by using only one screw driver;

2. It is strong in structure and durable in use;

3. By inserting the connecting bolts in the connectors respectively and then rotating the connectors relative to the connecting bolts, the stands and the side bars are conveniently firmly secured to the connecting bar or cross bars;

4. By alternatively aligning the channels of the side bars with the parallel grooves on the two pairs of supports, the seat can be conveniently adjusted to a suitable height;

5. By alternatively aligning the two rows of holes of the back support with the bolt holes and through-holes of the two pairs of supports, the back support can be conveniently adjusted to a suitable position to comfortably support the back of the person who sits on the seat;

6. It can be conveniently disassembled to reduce space occupation for convenient delivery or storage; and

7. It is easy and inexpensive to manufacture.