FOLDING CHAIR AND MOUNTING STRUCTURE OF VACUUM-FORMED BACKREST BOARD THEREOF

Description

RELATED APPLICATIONS

This application claims priority to Chinese patent application number 202420980723.1, filed on May 8, 2024. Chinese patent application number 202420980723.1 is incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to a folding chair and a mounting structure of a backrest board thereof, and in particular to a mounting structure of a vacuum-formed backrest board.

BACKGROUND OF THE DISCLOSURE

Folding chairs are classified by material, mainly including wooden folding chairs, metal folding chairs, and plastic-steel folding chairs. Among them, plastic-steel folding chairs are lighter in weight and more price-competitive, thus being widely used in daily life. For plastic-steel folding chairs, the seat plate and backrest plate are made of plastic parts, while the leg tubes are made of metal parts. The strength of plastic parts is poor, so the strength of the backrest plate often needs to be improved by increasing its thickness or adding reinforcing ribs on the back. In the early stages, the backrest plate was produced using injection molding. Increasing thickness or adding reinforcing ribs could be easily achieved by modifying the mold, but this inevitably led to a significant increase in the weight and cost of the backrest plate.

Currently, the profit margin for plastic-steel folding chairs is extremely limited, and market competition is intense. Only products that are lighter or lower in cost can remain competitive. To address this, researchers adopted thermoforming (vacuum forming) to produce the backrest plate. Vacuum-formed backrest plates are much thinner, significantly reducing both cost and weight. However, this method revealed a new issue: insufficient strength of the backrest plate. To ensure strength under vacuum forming, researchers naturally considered adding a metal support mesh or metal support plate behind the backrest plate. However, this approach was less aesthetically pleasing and noticeably increased weight, making it poorly received by consumers. Later, a solution was proposed: forming a curled-edge structure at a lower edge of the vacuum-formed backrest plate, which greatly improved strength of the vacuum-formed backrest plate. However, since the lower edge of the vacuum-formed backrest plate is not connected to metal tubes (the leg tubes) like other parts, deformation resistance of the vacuum-formed backrest plate remains weaker than other areas. When users lean forcefully against the vacuum-formed backrest plate, the perceived sturdiness still falls short. Therefore, further research and improvement on the strength and deformation resistance of the vacuum-formed backrest plate are still necessary.

BRIEF SUMMARY OF THE DISCLOSURE

The present disclosure provides a folding chair and a mounting structure of a vacuum-formed backrest board thereof, which improves strength and an anti-deformation capability of the vacuum-formed backrest board. The technical solution adopted by the utility model to solve the technical problem is described as follow.

A mounting structure of a vacuum-formed backrest board of a folding chair is provided. Edges of a left side and a right side of the vacuum-formed backrest board are folded rearward to form a fixed flange, and a surface of the fixed flange comprises one or more inverted buckling protruding teeth. The vacuum-formed backrest board is disposed between two leg tubes of the folding chair symmetrically disposed in a left and right direction, and the two leg tubes comprises a mounting buckling groove corresponding to the fixed flange. The fixed flange is disposed in the mounting buckling groove, and the one or more inverted buckling protruding teeth are buckled to an edge of the mounting buckling groove to inhibit the fixed flange from being separated from the mounting buckling groove. A lower edge of the vacuum-formed backrest board comprises a vacuum-formed bent edge extending rearward, and two ends of an edge banding strip are respectively connected to the two leg tubes of the folding chair. The edge banding strip comprises an insertion groove corresponding to the vacuum-formed bent edge at the lower edge of the vacuum-formed backrest board, and the vacuum-formed bent edge is wrapped by the edge banding strip.

A folding chair comprises four leg tubes, a vacuum-formed seat board, and a supporting mold frame. The four leg tubes comprise the two leg tubes and two additional leg tubes, and the four leg tubes support the supporting mold frame. The two leg tubes are symmetrically disposed in the left and right direction on a left side and a right side of the supporting mold frame to be configured as two front legs of the folding chair, and the additional two leg tubes are symmetrically disposed in the left and right direction on the left side and the right side of the supporting mold frame to be configured as two rear legs of the folding chair. The vacuum-formed backrest board is disposed between the two front legs. Edges of the left side and the right side of the vacuum-formed backrest board are folded rearward to form a fixed flange, and a surface of the fixed flange comprises one or more inverted buckling protruding teeth. The vacuum-formed backrest board is disposed between the two front legs of the folding chair symmetrically disposed in a left and right direction, and the two front legs comprises a mounting buckling groove corresponding to the fixed flange. The fixed flange is disposed in the mounting buckling groove, and the one or more inverted buckling protruding teeth are buckled to an edge of the mounting buckling groove to inhibit the fixed flange from being separated from the mounting buckling groove. A lower edge of the vacuum-formed backrest board comprises a vacuum-formed bent edge extending rearward, and two ends of an edge banding strip are respectively connected to the two leg tubes of the folding chair. The edge banding strip comprises an insertion groove corresponding to the vacuum-formed bent edge at the lower edge of the vacuum-formed backrest board, and the vacuum-formed bent edge is wrapped by the edge banding strip.

Compared with the existing techniques, the technical solution has the following advantages.

The vacuum-formed backrest board not only has a vacuum-formed bent edge at the lower edge, but the vacuum-formed bent edge is also wrapped by the edge banding strip. The vacuum-formed bent edge is no longer suspended between the two leg tubes, thereby enhancing the strength and deformation resistance of the lower edge of the vacuum-formed backrest board. After the edge banding strip wraps the vacuum-formed bent edge, the edge banding strip can also prevent the vacuum-formed bent edge from scratching hands, while also enhancing a substantial feel of the vacuum-formed backrest board.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

FIG. 1 is a perspective of a folding chair.

FIG. 2 is a perspective of the folding chair shown in FIG. 1 with an edge banding strip decomposed.

FIG. 3 is a cross-sectional view of the folding chair shown in FIG. 1 along a B-B line.

FIG. 4 is an enlarged view of a circle portion D in FIG. 3.

FIG. 5 is a cross-sectional view of the folding chair shown in FIG. 1 along a C-C line.

FIG. 6 is an enlarged view of a circle portion E in FIG. 5.

FIG. 7 is an enlarged view of a circle portion F in FIG. 5.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring to FIGS. 1 to 7, a folding chair comprises leg tubes 10, a vacuum-formed backrest board 20, a vacuum-formed seat board 30, and a supporting mold frame 40. The vacuum-formed seat board 30 is connected to the supporting mold frame 40. A number of the leg tubes 10 is four to cooperate with each other to support the supporting mold frame 40. Two of the leg tubes 10 are symmetrically disposed on a left side and a right side of the supporting mold frame 40 to be used as two front legs of the folding chair (the two front legs are longer, and the two front legs extends upward beyond the vacuum-formed seat board 30), and the other two of the leg tubes 10 are symmetrically disposed on the left side and the right side of the supporting mold frame 40 to be used as two rear legs of the folding chair. The vacuum-formed backrest board 20 is disposed between the two front legs. Reference can be made to existing structures with respect to a position and connection relationship of the leg tubes 10, the vacuum-formed backrest board 20, the vacuum-formed seat board 30, and the supporting mold frame 40. Edges of a left side and a right side of the vacuum-formed backrest board 20 are folded rearward to form a fixed flange 21, and a surface of the fixed flange 21 comprises one or more inverted buckling protruding teeth 22. The vacuum-formed backrest board 20 is disposed between the two front legs, and the two front legs comprise a mounting buckling groove 11 corresponding to the fixed flange 21. The fixed flange 21 is inserted into the mounting buckling groove 11, and the one or more inverted buckling protruding teeth 22 are buckled to an edge of the mounting buckling groove 11 to inhibit the fixed flange 21 from being separated from the mounting buckling groove 11. A lower edge of the vacuum-formed backrest board 20 comprises a vacuum-formed bent edge 23 extending rearward, and an edge banding strip 60 is provided. Two ends of the edge banding strip 60 are respectively connected to the two front legs of the folding chair, and the edge banding strip 60 comprises an insertion groove 61 corresponding to the vacuum-formed bent edge 23 at the lower edge of the vacuum-formed backrest board 20. That is, the vacuum-formed bent edge 23 can be inserted into the insertion groove 61, and the edge banding strip 60 wraps the vacuum-formed bent edge 23. The vacuum-formed bent edge 23 at the lower edge of the vacuum-formed backrest board 20 is covered by the edge banding strip 60, so stability is improved and strength is better.

Preferably, the two ends of the edge banding strip 60 are locked with the leg tubes 10 by screws 70. Further preferably, the screws 70 pass through the leg tubes 10 to be locked to the fixed flange 21. The screws 70 also are locked to the fixed flange 21 to inhibit movement of the fixed flange 21, so that the vacuum-formed backrest board 20 has better stability.

Preferably, the screws 70 are locked from an inner side of the leg tubes 10.

Preferably, the edge banding strip 60 is a plastic part.

Preferably, an upper edge and the edges of the left side and the right side of the vacuum-formed backrest board 20 are folded rearward to form the fixed flange 21. The fixed flange 21 on the vacuum-formed backrest board 20 extends continuously, and the one or more inverted buckling protruding teeth 22 are evenly spaced from each other on the fixed flange 21. Upper ends of the two front legs are connected by a connecting tube 80, and the connecting tube 80 comprises the mounting buckling groove 11. The fixed flange 21 on the upper edge of the vacuum-formed backrest board 20 is inserted into the mounting buckling groove 11 of the connecting tube 80. Further preferably, the fixed flange 21 on the vacuum-formed backrest board 20 extends continuously, and the one or more inverted buckling protruding teeth 22 are evenly spaced from each other on the fixed flange 21. The two front legs of the folding chair and the connecting tube 80 are formed by bending a same metal tube to be U-shaped.

The above description is only a preferred embodiment of the present disclosure, and should not be used to limit the scope of implementation of the present disclosure. That is, equivalent changes and modifications made according to the patent scope of the present disclosure and the contents of the specification should still fall within the scope covered by the present disclosure.