Folding Chair and Supporting Mold Frame Thereof for Vacuum-Formed Seat Board

This application claims priority to Chinese patent application number 202420978064.8, filed on May 8, 2024. Chinese patent application number 202420978064.8 is incorporated herein by reference.

The present disclosure relates to a folding chair and a supporting mold frame thereof for a seat board, and in particular to the supporting mold frame for a vacuum-formed seat board.

Folding chairs can be categorized by material, primarily including wooden folding chairs, metal folding chairs, and plastic-steel folding chairs. Among these, plastic-steel folding chairs are lighter in weight and more cost-effective, making them widely used in daily life. A plastic-steel folding chair includes a seat plate and a backrest which are made of plastic members, and a skeletal support structure of the plastic-steel folding chair is made of metal members. Since strength of the plastic members is significantly lower than that of metal, a load-bearing capacity of the plastic-steel folding chair largely depends on strength of the seat plate.

To ensure the plastic seat plate meets strength requirements, manufacturers typically increase a thickness of the plastic seat plate or add reinforcing ribs underneath to enhance bending resistance. In the past, the plastic seat plates were produced using injection molding, where increasing thickness or adding reinforcing ribs could be easily achieved by modifying the mold. However, this inevitably led to a substantial increase in both the weight and cost of the seat plate.

Currently, the profit margin for the plastic-steel folding chairs is extremely limited, and market competition is intense. Only products that are lighter or more cost-effective can remain competitive. To address this, researchers have adopted vacuum forming to produce the seat plates. Vacuum-formed seat plates are much thinner, significantly reducing both cost and weight. However, this method introduces a new challenge: insufficient seat plate strength. Researchers have devoted considerable effort to improving the strength of the vacuum-formed seat plates. Eventually, they developed two effective solutions. First, adhesive is used to bond the vacuum-formed seat plates to supporting frames, enhancing its bending resistance. Second, the support frame is extended to form a pressing edge to secure an edge of the vacuum-formed seat plate, further improving bending resistance. Both methods have proven highly effective, resulting in products that meet strength requirements while being lighter and more cost-effective than injection-molded alternatives.

Nevertheless, the drive to optimize and improve plastic-steel folding chairs continues. Consumers have higher expectations, particularly hoping that—despite being much lighter and cheaper than injection-molded products—the strength and deformation resistance of the vacuum-formed seat plates can rival those of injection-molded ones.

The present disclosure provides a folding chair and a supporting mold frame of the folding chair for the vacuum-formed seat board, which improves strength and an anti-deformation ability of the vacuum-formed seat board. The technical solution adopted by the present disclosure to solve the technical problem is described as follow.

A supporting mold frame of a folding chair for a vacuum-formed seat board comprises a supporting frame and one or more supporting abutting members. The vacuum-formed seat board comprises a seat panel and a side extending downward from all sides of the seat panel, and the supporting frame abuts an inner side of the side.

The one or more supporting abutting members connected to an inner side of the supporting frame, and the vacuum-formed seat board covers the one or more supporting abutting members. The one or more supporting abutting members support a bottom surface of the seat panel adjacent to a peripheral edge of the seat panel, the one or more supporting abutting members support a left side and a right side of the bottom surface of the seat panel, or the one or more supporting abutting members support the left side and the right side of the bottom surface of the seat panel adjacent to corners of the seat panel.

A folding chair comprises four leg tubes, a backrest board, a vacuum-formed seat board, and a supporting mold frame. The vacuum-formed seat board comprises the seat panel and the side extending downward from all sides of the seat panel. The supporting mold frame comprises the supporting frame and the supporting frame abuts the inner side of the side. The folding chair comprises one or more supporting abutting members, and the vacuum-formed seat board covers the one or more supporting abutting members. The one or more supporting abutting members support the bottom surface of the seat panel adjacent to the peripheral edge of the seat panel, the one or more supporting abutting members support the left side and the right side of the bottom surface of the seat panel, or the one or more supporting abutting members support the left side and the right side of the bottom surface of the seat panel adjacent to corners of the seat panel.

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

A distance between the left side and the right side of the vacuum-formed seat board is large, and a user can easily twist his/her body in a left and right direction when sitting on the vacuum-formed seat board. Therefore, the vacuum-formed seat board has weak points on the left and right sides of the seat panel. The present application connects the one or more supporting abutting members on the inner side of the supporting frame. The one or more supporting abutting members are used to support all sides of the seat panel of the vacuum-formed seat board, at least supporting the left side and the right side of the seat panel and/or adjacent to the seat panel. This can effectively improve the strength and anti-deformation ability of the seat panel of the vacuum-formed seat board at a position of the side, thereby improving a load-bearing capacity of the folding chair. In other words, when a thickness of the vacuum-formed seat board remains unchanged, a better load-bearing effect can be achieved.

Referring to, a folding chair comprises four leg tubes, a backrest board, a vacuum-formed seat board, and a supporting mold frame. The vacuum-formed seat boardis mounted on the supporting mold frame, and the four leg tubesare divided into two sets of two leg tubessymmetrically disposed on a left side and a right side of the supporting mold frameto support the supporting mold frame. The backrest boardis mounted between two leg tubes of the four leg tubesextending upward beyond the left and right side of the supporting mold frame. Reference can be made to existing structures with respect to a position and connection relationship of the four leg tubes, the backrest board, the vacuum-formed seat board, and the supporting mold frame. The vacuum-formed seat boardcomprises a seat paneland a sideextending downward from all sides of the seat panel. The supporting mold framecomprises a supporting frame, and the supporting frameabuts an inner side of the side. That is, the supporting framesurrounds and abuts the inner side of the side, and reference can be made to existing structures with respect to a position relationship between the sideand the supporting frame. The supporting mold framefurther comprises a plurality of supporting abutting membersconnected to an inner side of the supporting frame, and the plurality of supporting abutting memberssupport a left side and a right side of a bottom surface of the seat paneladjacent to corners of the seat panel. In this embodiment, the plurality of supporting abutting membersare four supporting abutting membersrespectively supporting a front end and a rear end of the left side of the bottom surface of the seat paneladjacent to the corners of the seat paneland a front end and a rear end of the right side of the bottom surface of the seat paneladjacent to the corners of the seat panel. It can be understood that the plurality of supporting abutting memberscan also be two supporting abutting membersrespectively supporting the left side and the right side of the bottom surface of the seat panel(as shown in, the two supporting abutting membersare longer and are used to support a left side and a right side of the seat panel). Alternatively, the supporting mold framefurther comprises a single supporting abutting membersupporting the bottom surface of the seat paneladjacent to a peripheral edge of the seat panel. That is, the supporting abutting membercan be an annular structure.

Preferably, the supporting frameand the plurality of supporting abutting membersare connected together by rivetsfor mounting the four leg tubes. The rivetsare used to connect the four leg tubesto the supporting frameand are conventional structures. The rivetsalso pass through the sideof the vacuum-formed seat board. In this way, the plurality of supporting abutting membersare directly mounted in place using the rivetson the four leg tubes, and the structure is simpler. It can be understood that when the plurality of supporting abutting membersare mounted in place not using the rivets, the plurality of supporting abutting memberscan instead be locked on the supporting frameby screws.

Preferably, the plurality of supporting abutting membersare plastic members, and the plurality of supporting abutting memberssupport the left side and the right side of the bottom surface of the seat panelof the vacuum-formed seat board, which can effectively reduce an inner cantilever of the seat panel, thereby effectively improving strength of the seat panel. Use of the plastic members can meet requirements and is light in weight. Further preferably, a portion of the plurality of supporting abutting membersused to support the seat panelis a hollow structure.

Preferably, outer sides of a left side and a right side of the vacuum-formed seat boardare disposed with sliding rods, and the rivetsconnect the four leg tubes, the sliding rods, the side, the supporting frame, and the plurality of supporting abutting members. The sliding rodsare mounted so that the supporting frameand the four leg tubeshave an ability to flip when the folding chair is folded, and the sliding rodsare also conventional structures.

Preferably, the sideof the vacuum-formed seat boardcomprises a reinforcing stepexpanding outwardly, and an upper end of the supporting frameforms a pressure-bearing step. The pressure-bearing stepsupports the reinforcing step. Therefore, the supporting framenot only surrounds and abuts the inner side of the side, but also supports the side, further improving the strength of the vacuum-formed seat board.

The above description is only a preferred embodiment of the present disclosure, and therefore 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.