Ergonomic chair
First Claim
1. A chair comprising:
- a frame member having a first support portion and a second support portion and a pair of space elongated rigid support members connected to opposite sides of a central control member;
a seat member pivotably connected to said first support portion and having a rear support;
a backrest member having an upper support portion and a front support portion, said upper support portion of the backrest being pivotably connected to an upper end of the second support portion of the frame member, said upper support portion of said backrest member includes a transverse frame member having opposite ends and each of said support members is connected to an end of said transverse frame member; and
a link member pivotably connected to the rear support of the seat member and pivotably connected to the front support of the backrest member;
wherein tilting movement of the backrest rearwardly relative to the frame member causes elevation of a rear portion of the seat member upon weight shifting of the chair user and wherein the seat member and backrest member have a relative center of rotation approximately coincident with the center of rotation of the hip joint of the user.
3 Assignments
0 Petitions
Accused Products
Abstract
An ergonomic chair includes a four-bar linkage arrangement wherein a lower frame member is provided with a rigid front support and a rigid rear support with a seat member pivotably connected to the front support. A back rest has an upper support pivotably connected at an upper end of the rear support of the lower frame member. A link member pivotably connects at a first end to a rear support of the seat member and at second end to a lower support of the back rest. This novel arrangement permits tilting movement of the backrest rearwardly relative to the lower frame member causing elevation of a rear portion of the seat member, permitting the feet to remain on the floor and alleviating pressure on the user'"'"'s thighs.
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Citations
18 Claims
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1. A chair comprising:
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a frame member having a first support portion and a second support portion and a pair of space elongated rigid support members connected to opposite sides of a central control member;
a seat member pivotably connected to said first support portion and having a rear support;
a backrest member having an upper support portion and a front support portion, said upper support portion of the backrest being pivotably connected to an upper end of the second support portion of the frame member, said upper support portion of said backrest member includes a transverse frame member having opposite ends and each of said support members is connected to an end of said transverse frame member; and
a link member pivotably connected to the rear support of the seat member and pivotably connected to the front support of the backrest member;
wherein tilting movement of the backrest rearwardly relative to the frame member causes elevation of a rear portion of the seat member upon weight shifting of the chair user and wherein the seat member and backrest member have a relative center of rotation approximately coincident with the center of rotation of the hip joint of the user. - View Dependent Claims (2)
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3. A chair comprising:
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a frame member having first support portion and second support portion wherein said second support portion is disposed rearwardly of said frame member;
a seat member pivotably connected to said first support portion and having a rear support;
a backrest member having an upper support portion and a front support portion, the upper support portion of the backrest member being pivotably connected to an upper end of the second support portion of the frame member; and
a link member pivotably connected to the rear support of the seat member and pivotably connected to the front support portion of the backrest member;
wherein tilting movement of the backrest rearwardly relative to the frame member causes elevation of a rear portion of the seat member upon weight shifting of the chair user and wherein the seat member and backrest member have a relative center of rotation approximately coincident with the center of rotation of the hip joint of the user.
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4. A chair having a tiltable back and a pivoting seat comprising:
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a base;
a support module attached to said base;
a generally horizontally extending frame having a lower front pivot and a higher rear pivot, said frame being rigidly attached to said base;
a seat mounted to said horizontally extending frame so as to be pivotable only about said lower front pivot, said seat having a rear portion including a third pivot;
a back frame disposed generally vertically and moveable between upright and tilted positions, said back frame having a top part, a bottom part and a middle part, said top and said middle parts for supporting a back, said bottom part being attached to a fourth pivot and said middle part being rotatably connected to said higher rear pivot; and
a link member pivotably mounted to said third and said fourth pivots wherein the elevational distance between said third and fourth pivots is greater when said back frame is in said upright position than when said back frame is in said tilted position. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A chair comprising:
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a frame member having a first support portion and a second support portion;
a seat member pivotably connected to said first support portion and having a rear support;
a backrest member having an upper support portion and a few support portion, the upper support portion of the backrest member being pivotably connected to an upper end of the second support portion of the frame member;
a link member pivotably connected to the rear support of the seat member and pivotably connected to the front support portion of the backrest member; and
at least one extension spring connected between the seat member and a pivot shaft which defines the pivotal connection between the link member and the front support portion of the backrest member;
wherein tilting movement of the backrest rearwardly relative to the frame member causes elevation of a rear portion of the seat member upon weight shifting of the chair user and wherein the seat member and a backrest member have a relative center of rotation approximately coincident with the center of rotation of the hip joint of the user.
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Specification