JP7717376B2 - Folding chair - Google Patents

Description

The present invention relates to a folding chair, and in particular to a folding chair that can stand on its own when folded.

Folding chairs with foldable front and rear legs and a seat are widely known (see, for example, Patent Document 1). The folding chair described in Patent Document 1 has front legs with a pair of front leg rods whose lower ends contact the floor, rear legs foldably pivotally attached to the middle of the front legs and with a pair of rear leg rods whose lower ends contact the floor, and a rotatable seat that moves between a seated position and a flip-up position when folded. A backrest is provided above the front legs. When this chair is folded, the front faces of the rear legs contact the rear faces of the front legs, and the lower ends of the front and rear legs are close together. However, because only the lower ends of the rear legs protrude downward, the chair cannot stand independently on the floor using only the rear legs. For this reason, folding chairs are typically stored by stacking them in a folded state, or by leaning them side by side on a storage support. Furthermore, because such folding chairs have a small gap between the contact points where the lower ends of the front and rear legs touch the floor, they can be unstable in the front-to-back direction when seated. In particular, if the seat height is set lower than normal, the gap between the contact points becomes even shorter, making the chair unstable; if the seat height is set higher than normal, the chair will similarly become unstable.

In addition, various configurations of backrests are known for being installed above the front legs. However, as shown in Figure 8, if the lower end of the backrest 50 is installed using mounting fixtures to protrude further rearward than the rear legs 51, when the front legs 52 and rear legs 51 are folded and placed on the floor 53, or when they are stacked on top of each other, the surface of the backrest 50 may rub against the floor, causing tears or damage.

Folding chairs have also been proposed that increase the gap between the ground-contact portions of the lower ends of the front and rear legs when folded (see, for example, Patent Document 2). The folding chair described in Patent Document 2 has front leg members formed in a generally S-shape with bent portions at the top and bottom of a vertically elongated body, and rear leg members formed in a generally inverted S-shape with bent portions facing in the opposite direction. The upper bent portions are rotatably connected by hinges in a facing relationship to form armrests. This configuration, in assembled form, improves stability compared to a chair without bent portions because the lower bent portions extend away from each other. However, in the folded state, the lower bent portions move closer together and become adjacent, so the gap between the ground-contact portions of the front tip of the bent portion of the front leg member and the rear tip of the bent portion of the rear leg member is significantly smaller than when in use. Furthermore, because the upper portions of the front and rear leg members protrude beyond this distance when folded, the weight from the leg members and seat acts outside the ground contact area. Furthermore, because the seat and backrest hang forward from the front leg members, the chair is unstable when standing on its own, prone to tipping over, and difficult to store compactly.

JP 2019-80773 A (FIGS. 1 to 5) JP 2018-153280 A (FIGS. 1 to 3, 9 to 12)

The problem solved by this invention is to provide a folding chair that can stand on its own when folded, can be stored efficiently, is stable when in use, and can be placed on the floor or other surface without damaging the seat cushion, even if part of the backrest protrudes backward.

The present invention provides a folding chair comprising front legs having a pair of front leg rods, rear legs having a pair of rear leg rods foldably connected parallel to the front legs, a seat supported by the front and rear legs so as to be rotatable between a folded position standing parallel to the front legs and a seated position, a back frame formed on the upper part of the front leg rods, and a backrest supported by the back frame, wherein the lower end of the front leg rod has a forward bent portion that bends forward and touches the floor, and the lower end of the rear leg rod has a rear bent portion that bends backward and touches the floor, and when the front and rear legs are folded, the forward bent portion and rear bent portion are formed to a length that allows the front legs, rear legs, seat, and backrest in their folded state to be accommodated in the upper part of the minimum distance between the front ground contacting portion where the forward bent portion touches the floor and the rear ground contacting portion where the rear bent portion touches the floor, and the folding chair is characterized in that the folding chair solves the above-mentioned problem.

The folding chair preferably has the lower part of the backrest rotatably supported on the rear leg rod by an attachment, and the upper part stored in the front of the back frame. A support rod is pivotally attached to the middle of the front legs, and this support rod is slidably inserted into the tip of the rear leg, connecting the rear and front legs foldably using a cylinder system. More preferably, the lower part of the backrest is located closer to the rear leg rod than an imaginary line connecting the back frame and the tip of the rear bent part of the rear leg, and ground caps are attached to the forward bent part and the rear bent part, with ground protrusions protruding downward from the ground caps.

The present invention is configured as described above, with front legs having a pair of front leg rods and rear legs having a pair of rear leg rods foldably connected in a substantially parallel state. The seat is supported between the front and rear legs so that it can be rotated between a seated position and a folded position substantially parallel to the front legs when folded, and a back frame is formed on the upper part of the front leg rods to support the backrest. The lower end of the front leg rod is provided with a forward bent portion that bends forward to contact the floor, and the lower end of the rear leg rod is provided with a rear bent portion that bends backward to contact the floor. Therefore, when the front and rear legs are unfolded, the front ground contacting portion where the forward bent portion contacts the floor and the rear ground contacting portion where the rear bent portion contacts the floor are spaced apart in the front-to-rear direction. The forward and rear bent portions allow for a greater maximum separation distance than conventional folding chairs, allowing for a more stable sitting position than conventional chairs.

When folded, the front ground contact portion of the forward bent portion and the rear ground contact portion of the rear bent portion move toward each other, but the minimum separation between the ground contact portions can be made larger compared to conventional folding chairs without bent portions. Furthermore, the forward bent portion and rear bent portion are configured to a length that allows the front legs, rear legs, seat, and backrest in the folded state to fit within the upper portion of this minimum separation between the ground contact portions. Therefore, when folded, the load from the front legs, rear legs, seat, backrest, etc. is stably supported between the spaced-apart forward bent portion and rear bent portion, allowing the chair to stand on its own. Being able to stand on its own in this folded state allows for efficient, compact storage.

Furthermore, if the lower portion of the backrest is positioned closer to the rear leg rod than the imaginary line connecting the back frame and the tip of the rear bent portion of the rear leg, a space can be created between the floor and the lower portion of the backrest when the chair is placed on the floor in the folded state, eliminating the risk of damaging the backrest's surface. Furthermore, if ground caps are attached to the forward bent portion and rear bent portion and ground protrusions that protrude downward are provided on the underside of the ground caps, damage to the floor will not occur and the ground caps themselves can be used for a long period of time.

1 is a perspective view showing an embodiment of the present invention; Side view of the state of use Side view of the folded state. Plan view of multiple storage locations. Side view of multiple storage locations. An explanatory diagram of how it looks when folded and placed on the floor. FIG. 1 is an explanatory diagram of a conventional folding chair.

Figure 1 shows one embodiment of a folding chair of the present invention. In this specification, the side facing forward when seated will be referred to as the "front" and the rear side as the "rear." As shown in Figure 1, the chair comprises front legs 1 each having a pair of front leg rods 2 formed from a pipe material with a circular cross section, and rear legs 3 each having a pair of rear leg rods 4 pivotally attached to the middle of the front legs 1 in a foldable manner. The left and right front leg rods 2 and rear leg rods 4 are connected by front leg connecting rods 5 and rear leg connecting rods 6, respectively. A back frame 7 is formed above the front legs 1, curving backward and extending continuously with the left and right front leg rods 2.

The rear legs 3 are connected to the front legs 1 in a manner that allows them to fold in a generally parallel position. While various connection configurations are possible, a preferred method is to connect the rear legs 3 and front legs 1 using a cylinder, as shown in the embodiment shown in Figure 1. Specifically, a support rod 8 is pivotally attached to the middle of the front legs 1 with a pin 9, and the lower end of this support rod 8 is slidably inserted into the rear leg lever 4. With this configuration, when folding, the rear leg lever 4 acts as a cylinder, allowing the rear legs 3 to slide and rotate vertically, allowing them to unfold and fold. When unfolded, the inner tip of the support rod 8 (not shown) hits a stopper 10 to prevent fingers from getting caught (not shown).

The seat 11 is rotatably mounted with its middle section pivoted to the front legs 1 by pins 12 and its rear section pivoted to brackets 13 attached to the tops of the rear legs 3. With this configuration, as shown in Figure 1, when the folding chair is unfolded, the seat 11 is held in a nearly horizontal seating position. When folded, the rear legs 3 rotate and move downward, causing the front section of the seat 11 to flip up and move to a folded position where it stands nearly parallel to the front legs 1 (see Figure 3).

A backrest 14 is supported on the back frame 7. The backrest 14 can be configured in various ways, but preferably, as shown in the embodiment, the upper portion of the backrest is stored on the front side of the back frame 7 so that it can move up and down, and the lower portion extends in the direction of the rear leg rods. As shown in side views such as Figure 2, a roughly L-shaped attachment 15 is provided on the lower portion of the backrest 14, and this attachment 15 is rotatably pivoted to the inside surface of the rear leg. With this configuration, when folding, the rear leg 3 rotates and moves downward, causing the backrest 14 to move downward along the back frame 7, and when unfolding, it moves upward.

The lower end of the front leg rod 2 is provided with a forward bent portion 17 that bends forward and extends in a direction that contacts the floor surface 16, and the lower end of the rear leg rod 4 is provided with a rear bent portion 18 that bends backward and extends in a direction that contacts the floor surface 16. Preferably, a ground cap 19 is attached to the tip of each bent portion 17, 18. When the folding chair is unfolded, the forward bent portion 17 and the rear bent portion 18 move significantly apart in the front-to-rear direction, and the distance between the front ground surface 20 where the forward bent portion 17 contacts the floor surface 16 and the rear ground surface 21 where the rear bent portion 18 contacts the floor surface 16 is the maximum separation distance L1. When the front legs 1 and rear legs 3 are folded, the front ground surface 20 and the rear ground surface 21 move closer together, and the distance between the front and rear ground surfaces is the minimum separation distance L2. This minimum separation distance L2 is much greater than the distance between the ground surfaces of conventional folding chairs when folded. The lengths of the forward bent portion 17 and the rear bent portion 18 are formed so that the front legs 1, rear legs 3, seat 11, and backrest 14 in the folded state can be accommodated in the upper portion of the minimum separation distance L2 between the front ground contact portion 20 and the rear ground contact portion 21.

The grounding cap 19 attached to the forward bend 17 and rear bend 18 is made of plastic, and the underside of the grounding cap is provided with a grounding protrusion 22 of a required thickness that protrudes downward toward the floor surface 16. This grounding cap 19 prevents damage to the floor surface 16, and the grounding protrusion 22 allows the grounding cap 19 itself to be used for a long period of time.

When the lower portion of the backrest 14 is attached to the rear leg rod 4 of the rear leg 3 with the mounting bracket 15 as shown in the embodiment, the rear surface of the upper portion of the backrest 14 is supported by the back frame 7, but the rear surface of the lower portion is located further rearward than the rear leg rod 4. Therefore, when the chair is placed on the floor 16 in the folded state, the cover of the backrest 14 may be rubbed and damaged. Therefore, as shown in Figure 3, in this invention, the lower portion of the backrest 14 is positioned closer to the rear leg rod 4 than an imaginary line 23 connecting the back frame 7 and the rear end of the rear bent portion 18 of the rear leg 3. With this configuration, as shown in Figure 6, the imaginary line 23 is substantially aligned with the floor 16, preventing the lower portion of the backrest 14 from coming into contact with the floor 16 and preventing damage.

With the above-described configuration, the folding chair of the present invention has forward bent portions 17 and rearward bent portions 18 spaced apart in the front-to-rear direction when in use, resulting in a larger maximum separation distance L1 between the front and rear ground contact portions 20, 21 than conventional folding chairs, allowing for stable seating. Furthermore, while the rear legs 3 and seat 11 are folded approximately parallel to the front legs 1, the minimum separation distance L2 between the front bent portions 17 and rearward bent portions 18 is larger than that of conventional folding chairs. Furthermore, the lengths of the forward bent portions 17 and rearward bent portions 18 are designed to allow the front legs 1, 3, etc., in the folded state, to be stored above the minimum separation distance L2, allowing the folding chair to stand on its own without tipping over. Furthermore, when storing multiple chairs in the front-to-rear direction, stacking the second chair with its center offset by the thickness of the rear leg pipe of the first chair and aligning the third chair with the center of the first chair allows for efficient storage, as shown in Figures 4 and 5.

Figure 7 shows another embodiment of a folding chair with casters 24 attached to the forward bending portion 17 and the backward bending portion 18. When attaching such casters 24, the bending portions 17, 18 extend in the front-to-rear direction, making installation easy and ensuring running stability.

1 Front leg 2 Front leg rod 3 Rear leg 4 Rear leg rod 7 Back frame 11 Seat 14 Backrest 17 Front bending part 18 Back bending part 19 Grounding cap 20 Front grounding part 21 Rear grounding part

Claims (1)

a front leg having a pair of front leg rods;
rear legs each having a pair of rear leg rods foldably connected in parallel to the front legs;
a seat supported by the front and rear legs so as to be rotatable between a folding position in which the seat stands parallel to the front legs and a seating position; and a back frame formed on an upper portion of the front leg rods;
A backrest supported by the back frame is provided,
a folding chair in which the lower end of each front leg rod is provided with a forward bent portion that bends forward and touches the floor surface, and the lower end of each rear leg rod is provided with a rear bent portion that bends backward and touches the floor surface, and when the front and rear legs are folded, the forward and rear bent portions are formed to a length that allows the front and rear legs, seat and backrest in their folded state to be stored in the upper part of the minimum distance between the front ground contacting portion where the forward bent portion touches the floor surface and the rear ground contacting portion where the rear bent portion touches the floor, and further, the lower part of the backrest is rotatably supported on the rear leg rod by an attachment device, the upper part is stored in front of the back frame, and the lower part of the backrest is located on the rear leg rod side of an imaginary line connecting the back frame and the rear ends of the rear bent portions of the rear legs .