Patent Application
20110006564
Not Applicable
Not Applicable
Not Applicable
1. Field of the Invention
The present invention relates generally to collapsible or folding chairs. More particularly, the invention concerns a novel folding chair having a uniquely configured curved back support that provides superior back support for a person seated upon the chair.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Collapsible chairs are well known around the world as convenient options for seating at locations where seating is otherwise unavailable. They are easily stored, transported and set up for a variety of indoor and outdoor uses including camping, fishing, painting, sporting events, or concerts and parties. The time spent in these chairs is often over several hours. However, most of the collapsible chairs in use today do not have enough back support necessary for a healthy spine when used for sitting for these lengthy periods of time.
According to the American Chiropractic Association, one-half of all working Americans admit to having back pain symptoms each year and experts estimate that as many as 80% of the population will experience a back problem at some time in their lives. The importance of back-support in office chairs, where people sit for hours at a time, is well known to users and manufacturers. Entire fields of study within ergonomics and medicine have resulted from the magnitude of the need for proper posture when seated. However, a negligible amount of attention has been given to the importance of back support in folding chairs despite their widespread use.
A popular type of collapsible chair is the “sling” or “quad” chair where the chair membrane is supported at four points, two on the top of the chair back-rest and two on the end of the chair seat, creating a “sling” or hammock-like look and feel where the membrane sags in-between the four points of support. The problem with this configuration is there is no support for the back. And, unlike lying horizontally in a hammock, a seated person's back is closer to vertical which transfers their weight directly onto their spine. When seated in these types of chairs, a person's lower back bends to conform to the sagging curve of the membrane material, a direction that is the reverse of the natural curve of the lower back, thus placing tremendous stress on the intervertebral disks of the spine. This stress results in an often uncomfortable, sometimes painful, and always unhealthy, round curve of the lower back that can have long lasting effects on a person's quality of life.
Other collapsible chairs differ from the “sling” type chairs by having the chair membrane attached at more than four points. For example, some chairs have the membrane attached continuously along straight back support members. However, these chairs are only marginally better than the “sling” type configuration for back support. When a person sits in these chairs, their weight stretches the membrane, causing the same problem as found in the sling chairs; the lower back bends in the reverse direction from its natural curve to conform to the curve of the membrane material, thus placing unnatural stress on their spine. Even if the membrane could remain perfectly straight under a person's weight, these chairs would be inadequate because they would not match the natural curve of the human spine. That is, even straight chair-backs allow the spine to bend out of the natural, healthy, reverse-curved position.
Because people are different sizes and have different amounts of curve to their spine it stands to reason that any back support system needs to fit the needs of the individual. Some attempts have been made to make adjustable back support mechanisms in collapsible chairs, such as in U.S. Pat. No. 5,882,068 (E. R. Levine, 1999) but adjustable supports like these have disadvantages because they add manufacturing expenses, materials, weight, and tend to break more easily than chairs without moving parts. For chairs that are often used in harsh field conditions, these features are key considerations of distributors and buyers. Other collapsible chairs with adjustable back support, such as the Ergopod, have additional disadvantages in that they are visually unappealing due to strange “contraption-like” appearances.
It is therefore necessary to develop a collapsible chair that provides adequate back support that includes all of the advantages of existing collapsible chairs with no disadvantages due to the inclusion of a back support mechanism. As such, this chair should be easily set-up, collapsible, storable and transportable. It should also be visually appealing, durable, and fit the needs of a wide range of people.
By way of brief summary, the folding chair of the present invention comprises a frame including a seat portion, a front leg portion pivotally connected to the seat portion, a rear leg portion pivotally connected to the seat portion and a back portion connected to the seat portion. The back support portion of the folding chair uniquely comprises a pair of transversely spaced apart, forwardly extending convex members that are so constructed and arranged to match the curve of the lumbar region of the spine of a person seated on the folding chair. A flexible membrane covers the seat portion and the pair of transversely spaced apart, forwardly extending convex members to define a back support region that closely matches the curve of the lumbar region of the spine of a person seated on the folding chair.
With the forgoing in mind, it is an object of the present invention to provide a foldable chair having a uniquely configured curved back support that provides superior back support for a person seated upon the chair.
Another object of the invention is to provide a foldable chair of the character described in which the back portion of the chair is uniquely designed to provide a curved back support region that closely matches the curve of the lumbar region of the spine of a person seated on the folding chair.
Another object of the invention is to provide a foldable chair of the aforementioned character that is visually appealing, durable, and provides healthy back support that fits the needs of a wide range of people. More particularly, the foldable chair of the invention is uniquely designed to fit people of different heights and different back-arch preferences.
Another object of the invention is to provide a foldable chair as described in the preceding paragraphs that is easy to set-up, collapse, store, and transport.
The forgoing as well as other objects of the invention will be achieved by the novel foldable chair illustrated in the attached drawings and described in the specification that follows.
Referring to the drawings and particularly to
As best seen in
Forming an important aspect of the folding chair of the present invention is a back portion 38 that is connected to and extends upwardly from the seat portion 14. In the present form of the invention, the important back support portion comprises the previously mentioned upward extension 22a of front leg portion 16 and a pair of transversely spaced apart, forwardly extending, strategically shaped, convex members 40 that are connected proximate their upper end to upward extension 22a of the front leg portion 16 (see
As best seen in
As indicated in
Another unique feature of the foldable chair of the present invention resides in the fact that the chair adapts to fit people of different heights due to the fact that the membrane 42 has some give (is not completely rigid as found in a solid material like wood or metal) and further that the arc of the A-2 and A-3 is gently rounded or gradual (not sharp or abrupt). The membrane 42, although taught, exhibits enough give to conform to the seated person's back when leaned against, but not so much give as to lose the reverse curve shape as previously discussed. The arc A-2 through A-3, instead of being a sharp band providing merely a few vertical inches of support along a person's spine, matches the gentle curve in an average person's spine and provides support along the majority of a person's lower back. These novel features combine such that when people of different heights sit on the chair, the membrane 42 only needs to give (move) a small amount to conform to a large diversity of people, both shorter and taller than average, to provide a continuous area of back support.
The arc formed by the seat back portion also advantageously fits people with different preferences for the amount of arch in their back (e.g. some people like to sit in a chair that supports a large arch to their back). More particularly, in order to adjust the amount of arc, the individual simply has to adjust the seating position in relation to the arc in order to alter the amount of arch in the back. Stated another way, the arc of the back portion of the chair is uniquely designed so that a person seated on the chair can move their position in the seat and rest their back upon a greater arc, causing a greater arching of their back, or a shorter arc, thereby minimizing arching of their back. As indicated in the drawings, the arc defined by the members 40 is located high enough off of the seat portion of a chair and is strategically curved so as to allow a seated person to slide their buttocks from a position that is not under the lower arc A-3, to a position that is well under the lower arc A-3, while keeping the remainder of their back firmly against the back portion. For example, if a seated person keeps their mid-back firmly against the back portion and slides their buttocks to the rear of the chair, further under the lower arc A-3, their back will rest against a larger portion of the arc A-2 and A-3 causing a correspondingly larger amount of arch to their back.
In use, the folding chair of the present invention can be readily folded into the configuration shown in
Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.
