Folding Chair and Mounting Structure of Vacuum-Formed Backrest Board Thereof

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.

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.

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.

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.

Referring to, a folding chair comprises leg tubes, a vacuum-formed backrest board, a vacuum-formed seat board, and a supporting mold frame. The vacuum-formed seat boardis connected to the supporting mold frame. A number of the leg tubesis four to cooperate with each other to support the supporting mold frame. Two of the leg tubesare symmetrically disposed on a left side and a right side of the supporting mold frameto 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), and the other two of the leg tubesare symmetrically disposed on the left side and the right side of the supporting mold frameto be used as two rear legs of the folding chair. The vacuum-formed backrest boardis 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, the vacuum-formed backrest board, the vacuum-formed seat board, and the supporting mold frame. Edges of a left side and a right side of the vacuum-formed backrest boardare folded rearward to form a fixed flange, and a surface of the fixed flangecomprises one or more inverted buckling protruding teeth. The vacuum-formed backrest boardis disposed between the two front legs, and the two front legs comprise a mounting buckling groovecorresponding to the fixed flange. The fixed flangeis inserted into the mounting buckling groove, and the one or more inverted buckling protruding teethare buckled to an edge of the mounting buckling grooveto inhibit the fixed flangefrom being separated from the mounting buckling groove. A lower edge of the vacuum-formed backrest boardcomprises a vacuum-formed bent edgeextending rearward, and an edge banding stripis provided. Two ends of the edge banding stripare respectively connected to the two front legs of the folding chair, and the edge banding stripcomprises an insertion groovecorresponding to the vacuum-formed bent edgeat the lower edge of the vacuum-formed backrest board. That is, the vacuum-formed bent edgecan be inserted into the insertion groove, and the edge banding stripwraps the vacuum-formed bent edge. The vacuum-formed bent edgeat the lower edge of the vacuum-formed backrest boardis covered by the edge banding strip, so stability is improved and strength is better.

Preferably, the two ends of the edge banding stripare locked with the leg tubesby screws. Further preferably, the screwspass through the leg tubesto be locked to the fixed flange. The screwsalso are locked to the fixed flangeto inhibit movement of the fixed flange, so that the vacuum-formed backrest boardhas better stability.

Preferably, the screwsare locked from an inner side of the leg tubes.

Preferably, the edge banding stripis a plastic part.

Preferably, an upper edge and the edges of the left side and the right side of the vacuum-formed backrest boardare folded rearward to form the fixed flange. The fixed flangeon the vacuum-formed backrest boardextends continuously, and the one or more inverted buckling protruding teethare evenly spaced from each other on the fixed flange. Upper ends of the two front legs are connected by a connecting tube, and the connecting tubecomprises the mounting buckling groove. The fixed flangeon the upper edge of the vacuum-formed backrest boardis inserted into the mounting buckling grooveof the connecting tube. Further preferably, the fixed flangeon the vacuum-formed backrest boardextends continuously, and the one or more inverted buckling protruding teethare evenly spaced from each other on the fixed flange. The two front legs of the folding chair and the connecting tubeare 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.