As we spend more and more time using computers, smartphones, tablets, and other devices, we inevitably end up spending more time sitting. Because prolonged sitting is uncomfortable, furniture manufacturers have developed ergonomically contoured, supportive chairs intended to help us through the day. Though these chairs are well intentioned, the more time we sit passively with back support, the weaker our postural muscles become. Spending large amounts of time sitting passively tends to lead to postural degeneration and back pain. Furthermore, prolonged sitting has been correlated with increased risk of obesity, heart disease, cancer, and all-cause mortality.
Many furniture designers have become aware of the issues associated with passive sitting and have tried to solve the problem by creating devices that encourage people to sit actively. Though progress has been made, the sitting devices currently available have a variety of limitations.
One basic improvement over the traditional passive sitting device is to provide ways for the seat of the chair or stool to angle forward, opening up the hips to greater than 90 degrees in relation to the torso. Sitting with more open hips takes strain off the lower back, lengthens the hip flexors, and opens up the front of the body reducing compression of the user's internal organs. U.S. Pat. No. 7,387,339 to Bykov et al. (2008) and U.S. Pat. No. 4,807,841 to Edstrom (1989) allow for forward tilt while sitting. Though these sitting devices allow for a more open sitting angle, as conventional seats with backrests they discourage the user from actively supporting him or herself, and the user tends to slouch backward with extended sitting time.
A number of sitting devices have been made that open the angle of the user's pelvis and encourage active, dynamic sitting by allowing movement at the base of the central column. U.S. Pat. No. 5,746,481 to Obermeir (1998), U.S. Pat. No. 4,099,697 to Von Shuckmann (1978), and U.S. Pat. No. 5,921,628 to Glockl (1999) pivot angularly at or near the base of the central column allowing the user whole-body movement and encouraging the user to engage his or her legs while sitting. Though these types of sitting devices allow the user a wider range of whole-body movement than those described in the previous paragraph, they have two disadvantages. First, they rely on springs or elastic elements to bring the central shaft back to upright. Consequently, to whatever extent the user moves the seat and central column out of vertical alignment, his or her movement is met with greater mechanical resistance, reducing the need for the user to engage his or her core to remain upright. Secondly, the seats are rigidly set at ninety degrees to the central column allowing for limited freedom of movement of the user's pelvis and lumbar, thoracic, and cervical spine independent of the tilting of the central column.
U.S. Pat. No. 9,060,612 to Lee (2015) and U.S. Pat. No. 4,807,841 to Edstrom (1989) pivot just under the seat. These sitting devices afford the user an increased range of motion in the pelvis and lumbar, thoracic, and cervical spine front-to-back and side-to-side. However, because they include a base rigidly fixed at a right angle to the ground, they don't allow for the larger whole-body movements of the sitting devices mentioned in the previous paragraph.
European Patent Office patent 1997403 to Lenz et al. (2008) and U.S. Pat. No. 9,010,867 to Martin et al. (2015) afford the user a large range of motion by providing a base with a convex shape. These sitting devices don't rely on springs or other elastic mechanisms to return the central column and seat to upright. Instead, by virtue of their curved bases they come back to vertical alignment by means of gravity. Though this type of sitting device offers little resistance to off-axis tilt, because the base rolls in whatever direction the user leans, the result is that the user effectively has a solid support structure directly under where he or she sits requiring limited engagement of the legs and core muscles to remain upright.
European Patent Office patent 2988628 to Hugou et al. (2017) pivots freely at the base and allows for some pelvic, lumbar, and thoracic mobility by virtue of its small seat. However, the disadvantage of this sitting device is that it is unable to remain standing on its own, and it does not come back to vertical without the user picking up the device and placing it under him or her before sitting. Furthermore, the small sitting surface of the seat will tend to become uncomfortable with extended sitting.
Lastly, U.S. Pat. No. 3,863,587 to Bosnich (1975) pivots angularly between the seat and floor by means of a ball and socket joint, and a counterweight below the central pivot helps bring the seat to upright. Though this sitting device accommodates a wide range of motion and is self righting, it is intended for use by captains on ships to keep them upright while the boat pitches and rolls with the movement of the sea. To insure the user remains upright with as little effort as possible, the shaft below the ball and socket joint accommodates multiple weights.
To this end, U.S. Pat. No. 3,863,587 to Bosnich (1975) from the previous paragraph states, “Sufficient weights are added to more than counterbalance the weight of the occupant of the chair. More accurately, the weight of the occupant times the distance of the occupants [sic] center of gravity to the center of motion to the ball and socket joint must be less than the counterbalancing weights times the distance of their center of gravity to said center of motion. The occupant of the chair remains vertical with the horizon regardless of the roll and pitch of the ship.” Hence, the intended purpose of this sitting device is to reduce the activity needed by the user to remain upright. Furthermore, this sitting device has a backrest, demonstrating it is not intended to encourage active sitting.
In conclusion, insofar as I am aware, no sitting device formerly developed provides a sitting experience which:
An improved sitting device provides a means for the user to remain active with large movements of the whole body involving the user's legs and core muscles. It lets the user sit with a greater than ninety degree angle of the hips. Such a device allows for at least 10 degrees of angular movement of the seat and central column off the vertical axis, while affording the user a wide range of movement of the hips and lumbar, thoracic, and cervical spine. Furthermore, an improved sitting device stands on its own and returns to vertical exerting minimal resistance to the angular movement of the seat and central column off of the vertical axis. Such a sitting device has the advantage of requiring the continuous, active engagement of the user to remain balanced and upright using his or her legs and core muscles.
One embodiment of the sitting device is illustrated in
The padding of the seat 14 in the embodiment shown in
The seat 14 in the embodiment shown in
A side perspective view of the sitting device with a detailed labeling of parts is shown in
As show in the embodiment in
A top perspective view of the base 10 without the seat 14 is shown in
In this embodiment, the base 10 is made of a single piece of laminated wood that has been formed into a three-legged structure. However, the base 10 may comprise a horizontal platform with a plurality of legs, and may be made of injection-molded polymer, metal, solid wood, or any other material sufficiently strong to bear the weight of the user. The shape of the base 10 may vary as long as the counterweight 18 and central column 12 have sufficient space to move unimpeded.
A cross-sectional side view of the pivot joint 16 is shown in
The spherical plain bearing 32A and spherical plain race 32B in this embodiment are made of stainless steel with a PTFE liner (not shown) on the inside surface of the spherical plain race 32B that enhances the smooth movement of the unit without additional lubrication. Alternatively, the spherical plain bearing 32A and spherical plain race 32B may be made of nylon, composite materials, or other alloys, and similar movement may be achieved by a spherical ball bearing, gimbal bearing, spherical thrust bearing, or other means of angular movement. Lubrication of the unit may alternatively be provided with grease, liquid oils, or other lubricants.
A side perspective view of a person sitting on the device is shown in
In operation, one uses the device to sit actively while working at a desk, using a computer, playing video games, playing an instrument, meditating, or otherwise practicing mindful posture. The user may adjust the height of the seat 14 using the lever 20 to actuate the gas lift cylinder 24. The user sits with the top of the seat 14 at a height approximately equivalent to the distance from the floor to the top of the user's patella when standing barefoot, between 50 and 56 cm for an average adult. Sitting at this height opens up the angle of the user's torso in relation to his or her upper legs. Furthermore, the contoured shape of the seat 14 allows for an additional opening of this angle. Taking into account the angle of the pivot joint 16 combined with the contoured shape of the seat 14, the angle of the user's torso in relation to his or her upper legs opens up to between 100 and 120 degrees.
Because of the pivot joint 16, medially located between the seat 14 and the floor, the sitting device is inherently unstable when in use. Unlike traditional and modern ergonomic chairs, while using this sitting device the user must actively monitor his or her balance to remain upright. The user creates a stable, upright sitting position by sitting centrally atop the seat 14 and carrying approximately 25 percent of his or her body weight in his or her legs.
Furthermore, the angular movement of the pivot joint 16 encourages the user to rock side to side, fore and aft, and in circular motions. Moving in this way is both enjoyable and stimulates the muscles and joints of the legs, spine, and torso. Unlike traditional sitting devices, using this device tends to enhance the user's sense of balance, increase his or her level of physical and mental activity, and provide the pleasure of moving his or her body during otherwise physically passive activities.
An embodiment of the sitting device with a collar lock is shown in
An embodiment of the sitting device with a set screw is shown in
From the description above, a number of advantages of some embodiments of my sitting device become evident:
Accordingly, the reader will see that embodiments of the sitting device encourage active, dynamic sitting in the user and an increased attention to maintaining upright posture. Additionally, when the user is not sitting, the sitting device stands on its own, and the seat and central column return to vertical without him or her needing to reposition them. Furthermore, the embodiment with a column lock has additional advantages in that:
Additionally, the embodiments with a set screw inserted through the side of the race, extending toward the center of the spherical plain bearing have additional advantages in that:
Although the description above contains many specificities, they should not be construed as limiting the scope of the embodiments but as merely providing illustrations of some of several embodiments. For example, the seat can be configured in many shapes and sizes such as saddle-shaped or a rounded triangle, and the contours of the seat can be that of a donut, flat, or bumpy. The central pivot may be a spherical ball bearing, spherical thrust bearing, or other device that allows the central column and seat to move, and it may be lubricated by liquid oils, dry lubricants, or other means of lubrication. The base may be constructed as a single three-dimensional unit or with connected pieces such as legs and a horizontal surface in which to mount the central pivot, and it may be constructed of plastic, wood, rubber, or other materials of various properties, colors, and textures.
Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given.
Number | Date | Country | |
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62527541 | Jun 2017 | US |