An oscillation mechanism for a seat or a backrest of a chair or of an armchair is provided. The oscillation mechanism has a seat coupling, a backrest coupling, and a functional body made in a single piece of plastic material and consisting of a flexible unit portion, the functional body being elastically deformable by bending for the oscillation of the seat and of the backrest.

A chair includes a base structure, a seat support structure, a back frame comprising a front surface, a rear surface and a forwardly extending bottom portion pivotably connected to the base, a biasing member biasing the back frame from a reclined position toward an upright position, wherein the biasing member is located entirely forward a rearward most edge of the seat support structure, and a back shell comprising a forwardly extending bottom portion connected to the seat support structure, a front surface, a rear surface positioned in front of the front surface of the back frame, a pair of laterally spaced side portions defining an opening therebetween, and a top portion extending laterally between and connected to the side portions, wherein each of the side portions are exclusively connected to the back frame at a first location.

An ergonomic chair includes a support body having a seat support portion and a back support portion. A forward sloping seat track is positioned on the seat support portion. A first seat portion engages the seat track on the seat support portion for forward and rearward movement along the seat track between a forward position and a rearward position. A second seat portion is provided having an upwardly extending back rest. The second seat portion is pivotally connected to the first seat portion. Movement of the first seat portion forward along the seat track toward the forward position draws the second seat portion forward with forward movement of the second seat portion causing movement of the back rest downwardly. This allows for subtle movement forward and backward movement that energizes major leg muscles.

A seat tilting mechanism comprising a main body, a seat support, a backrest support and an articulation mechanism comprising a lever, a first portion of which defines along with a first arm, the seat support and the main body a first quadrilateral hinge, and a second portion of which defines alone with a second arm, the backrest support and the main body a second quadrilateral hinge. Interior corner angles and lengths of each side of the first and second quadrilateral hinges are such that a predetermined angular displacement ratio of the backrest support in relation to the seat support is provided. An extension resistance device is mounted between the main body and the first portion to provide resistance to rotation of the lever. A first end of the extension resistance device is rotationally mounted to the lever at a first mounting point, which is located between the midpoint and upper point, and is angularly displaced from a line extending between the midpoint and the upper point.

A folding chair device of the present invention includes a seat support assembly, a backrest assembly, a leg rest assembly, a backrest driving device, a connecting rod assembly and a leg rest driving device. A bottom of the backrest assembly is pivotally connected with the seat support assembly, the backrest driving device is pivotally connected with the backrest assembly; the leg rest assembly is pivotally connected with the seat support assembly, the leg rest driving device is mounted on the seat support assembly, and the connecting rod assembly is connected with a driving end of the leg rest driving device and pivotally connected with the leg rest assembly. The inclination angle of multiple assemblies of the device can be adjusted, and the device has a simple structure and low production cost, which is suitable for popularization in industry and daily life.

A seating furniture includes a seat device and a backrest device connected via at least one first rotatable coupling in respective coupling portions (P) of the backrest device and at rear portion (B) of the seat device. A base supports the seat device and the backrest device. The backrest device comprises a portion extending in a direction towards the base and past the first rotatable coupling, and the portion is rotatably coupled to and supported on the base via at least one respective link arm. The seat device is rotatably coupled to and supported on the base via a second rotatable coupling attached closer to front end (F) of the seat device than the first rotatable coupling. A lockable control device controls the movements between the backrest device and the seat device. The construction is well-balanced, and low forces are required to adjust the chair in all positions.

A swingable chair chassis comprises a rocker seat including a chamber defined between a bottom wall and a peripheral wall. The bottom wall includes a slot extending in a front/rear direction. A lid is securely mounted to a bottom of the seat and the rocker seat. A supporting seat is disposed in the chamber of the rocker seat. The supporting seat includes a central portion having an insertion hole coupled with chair post. The supporting seat includes an arcuate supporting face formed on an upper side thereof and abutting against a lower face of the lid. A plurality of elastic elements is disposed between the bottom wall of the rocker seat and the supporting seat and provides movement elasticity when the rocker seat swings forward or rearward relative to the supporting seat. The supporting face abuts against the lower face of the lid during swinging movement of the rocker seat.

A seating arrangement includes a back frame that includes a top portion, a bottom portion, and a pair of side portions that cooperate to define an opening, wherein at least one of the top portion, the bottom portion and the side portions include a longitudinally extending channel, a back shell having a forwardly facing support surface located within the opening and configured to support a seated user, and an attachment portion that extends about at least a portion of a periphery the support surface, and a cover member extending over the support surface, wherein the cover member is directly attached to the attachment portion of the back shell at an attachment location, and wherein the attachment location and the attachment portion of the back shell are located within the channel and concealed from view.

A reclining and declining chair, preferably one that rotates with respect to its base, having a chair seat frame or plate and having a vertical or generally vertical member that extends beneath to support is reclined and declined by tilting at least an upper portion of the vertical or generally vertical support. Optionally the chair can also have a reclining backrest and a leg/foot rest that can be raised and lowered. The tilting, reclining, declining and raising and lowering motions are accomplished by drive mechanisms that can be manually powered, electrically powered, fluid driven, etc. with operator controls allowing increased range and ease of reclining, declining plus other desirable advantages with these types of chairs.

A support mechanism for mounting a seat part to a foot part of a functional chair having a slide bearing which cooperates with a front section of the seat part, and a pivotable support part which is supported by a cantilever part and which is connected to a region of the seat part that is adjacent to the rear region of a seat surface section of the seat part.