In general, the present invention relates to the structure of armrests that are used on folding chairs, collapsible chairs, camp chairs, beach chairs and other portable lightweight chairs. More particularly, the present invention relates to the folding mechanism on the chair that enables the backrest of the chair to fold flat against the seat of the chair as the chair is folded closed.
Many chairs are designed to be foldable or collapsible so that they can be easily transported. In addition to be being foldable or collapsible, such chairs are made to be as lightweight as possible while still being functionally sound. In this manner, the chair is not burdensome to carry. Such chairs are often brought to the beach, to tailgate parties, to concerts and to other such locations that require a chair to be carried a significant distance.
In order to make a chair lightweight, a folding chair is typically manufactured with minimal components. Often the chair is little more than fabric stretched over some lightweight bent tubing to form a backrest and a seat. When the chair is folded, the seat is folded against the backrest so that the backrest and seat are close to parallel. The simplest way to make the seat of a folding chair fold against the backrest of a folding chair is to join the seat to the backrest at a simple hinged joint. One disadvantage of a hinge joint is that the joint causes the seat to engage the backrest at a slight angle. Accordingly, the seat and the backrest are not quite parallel when the folding chair is folded closed. The folding chair is, therefore, not as compact as it could be. Furthermore, if the chair is compressed flat while being packed or stored, the hinge can break or bend, therein damaging the chair.
To prevent the disadvantages presented by a simple hinged joint, many folding chairs use linkage hinges, where both the backrest and the seat are connected to intermediary linkages rather than to each other. Such linkage hinges are exemplified in U.S. Pat. No. 9,737,147 to Shadley and U.S. Pat. No. 6,698,828 to Chan. In order for a linkage hinge to work properly, certain compromises must be made in the design. The linkage used in prior art linkage hinges have fixed lengths. This fixed length is calculated to enable the seat to open and close. However, as is often is the case, the fixed length of the linkage prevents the chair from opening to a wide angle. As such, the linkage hinge is typically designed to be compromise that enables a folding chair to open and close, but to degrees less than would otherwise be desirable.
A need therefore exists for a folding chair with an improved linkage hinge that enables the chair to be both fully opened at a desired angle and fully closed without compromise. This need is met by the present invention as described and claimed below.
The present invention is a folding chair assembly with an improved folding mechanism. The folding chair assembly has a backrest structure, a seat structure, and an armrest structure that are all made from shaped tube forms. The tube form of the armrest structure is attached to the tube form of the backrest structure with a first pivot connection. The tube form of the armrest structure is also attached to the tube form of the seat structure at a second pivot connection.
A slotted linkage is provided that extends between the tube form of the backrest and the tube form of the seat. The slotted linkage is pivotably connected to either the backrest structure or to the seat structure. The slotted linkage defines a slot. The slot engages a fixed pin on either the seat structure or the backrest structure. The fixed pin reciprocally moves within the slot as said folding chair assembly is manipulated between a folded configuration and an open configuration. The complex movements enabled by the slotted linkage allow the backrest structure to fold flush against the seat structure, therein minimizing the bulk of the folding chair when in its folded configuration.
For a better understanding of the present invention, reference is made to the following description of an exemplary embodiment thereof, considered in conjunction with the accompanying drawings, in which:
Many different models of folding chairs have backrests and seats that fold against each other using a linkage hinge. The present invention can be adapted to most such folding chair designs. However, for the purposes of description and explanation, only one exemplary embodiment of a folding chair is being illustrated. The exemplary embodiment is selected in order to set forth one of the best modes contemplated for the invention. The illustrated embodiment, however, is merely exemplary and should not be considered a limitation when interpreting the scope of the appended claims.
Referring to
The second tube form is the seat tube form 24. The seat tube form 24 creates the rear leg support 26 and the seat structure 28 of the folding chair 10. The seat tube form 24 is also made of a single tube and has two free ends 29. The seat tube form 24 is also generally U-shaped having two parallel side sections 30 that are joined by a common crossbar section 32. A second fabric panel 34 is stretched between the two parallel side sections 30 to complete the seat structure 28 of the folding chair 10. The two parallel side sections 30 are contoured to form the rear leg support 26, whereby the seat structure 28 is elevated to a position a few inches above the crossbar section 32.
The third tube form is the armrest tube form 40. The armrest tube form 40 creates the front leg support 42 and the armrests of the folding chair 10. The armrest tube form 40 is a single tube with two free ends 44. The armrest tube form is also generally U-shaped having two parallel side sections 46 that are joined by a common crossbar section 48. The two parallel side sections 46 are contoured to create armrests that are elevated above, and adjacent the seat structure 28.
Referring to
The parallel side sections 16 of the backrest tube form 12 connect to the parallel side sections 46 of the armrest tube form 40 at pivot pin connections 54. The pivot pin connections 54 are positioned on the backrest tube form 12 just above the bend 50 of the dogleg 52. The pivot pin connections 54 are positioned on the armrest tube form 40 proximate its two free ends 44.
The armrest tube form 40 is directly connected to the seat tube form 24 with a second set of pivot pin connections 56. Accordingly, the armrest tube form 40 is directly connected to both the backrest tube form 12 and the seat tube form 24, therein interconnecting the backrest tube form 12 to the seat tube form 24.
The backrest tube form 12 is also connected to the seat tube form 24 via a set of slotted linkages 60. Each slotted linkage 60 is a bar of metal or plastic that has a first end 62 and a second end 64. The first end 62 is connected, via a pivot pin connection 66, to the backrest tube form 12 proximate the free ends 14 of the backrest tube form 12. A long slot 68 is formed in each slotted linkage 60. Each slot 68 extends between sixty percent and eighty percent of the length of the slotted linkage 60. Each slotted linkage 60 engages a fixed pin 70 that extends from the seat tube form 24.
In
Referring to
In
This reversed configuration is shown in
It will be understood that the embodiment of the present invention that is illustrated and described is merely exemplary and that a person skilled in the art can make many variations to that embodiment. All such embodiments are intended to be included within the scope of the present invention as defined by the claims.
Number | Date | Country | |
---|---|---|---|
Parent | 15968737 | May 2018 | US |
Child | 16840684 | US |