Office chair

Abstract

A chair with a reclining system that allows the back and seat to recline at different angles. The chair is provided with a first member, a second member, and a third member. The first member is pivotally attached to the second member and the third member, while the second member and the third member are pivotally and slidably attached together. The second member comprises an axle, which extends across the width of the third member, that is installed into open slots in the third member, thereby providing the pivotal and slidable connection. Assist springs and a height adjustment system is also provided.

We claim:  
     
         1 . A chair comprising: a first member; a second member pivotally attached to said first member; and a third member pivotally attached to said first member and pivotally and slidably attached to said second member, wherein said second member comprises an axle and said third member comprises a slot with an open end, said axle being received in said slot through said open end.  
     
     
         2 . The chair according to  claim 1  further comprising a stop attached to said first member, wherein said stop abuts said third member and thereby restricting forward and rearward movement of said first member.  
     
     
         3 . The chair according to  claim 1  further comprising a main spring biasing said first member away from a reclined position towards an upright position and an assist spring biasing said first member away from said reclined position towards an intermediate position between the reclined position and said upright position.  
     
     
         4 . The chair according to  claim 1  wherein said pivotal and slidable attachment between said third member and said second member comprises a fourth member slidably received in said slot, wherein said axle is pivotally attached to said fourth member and said axle extends across the width of said third member.  
     
     
         5 . The chair according to  claim 1  further comprising a main spring disposed between said third member and said axle of said second member.  
     
     
         6 . The chair according to  claim 4  further comprising a main spring disposed between a rear spring guide and a front spring guide, wherein said main spring is compressed when said first member moves towards a rearward position.  
     
     
         7 . The chair according to  claim 6  wherein said front spring guide is attached to said fourth member.  
     
     
         8 . The chair according to  claim 4  further comprising a stop restricting forward movement of said first member.  
     
     
         9 . The chair according to  claim 8  wherein said stop is fixedly attached to said first member.  
     
     
         10 . The chair according to  claim 9  wherein said stop abuts against a first surface of said third member and thereby restricting forward movement of said first member.  
     
     
         11 . The chair according to  claim 10  wherein said stop restricts rearward movement of said first member by abutting a second surface of said third member.  
     
     
         12 . The chair according to  claim 11  wherein said first surface and said second surface of said third member defines a top side and a bottom side of a stop slot in said third member.  
     
     
         13 . The chair according to  claim 12  wherein said first member comprises a yoke, said second member comprises a seat support, said third member comprises a base, and said fourth member comprises a bearing guide.  
     
     
         14 . The chair according to  claim 13  further comprising a back attached to said yoke, a seat attached to said seat support, and a chair stem assembly fixedly attached to said base in a plane transverse to said pivotal attachment between said base and said yoke.  
     
     
         15 . The chair according to  claim 4  further comprising an assist spring biasing said first member after the first member moves away from an upright position.  
     
     
         16 . The chair according to  claim 15  wherein said assist spring is compressed as said first member moves between an intermediate position and a reclined position.  
     
     
         17 . The chair according to  claim 16  wherein said assist spring is compressed between said third member and said fourth member.  
     
     
         18 . The chair according to  claim 4  further comprising a main spring biasing said first member from a rearward position to a forward position, a stop restricting forward movement of said first member, and an assist spring biasing said first member from said rearward position to an intermediate position.  
     
     
         19 . The chair according to  claim 18  wherein said first member comprises a yoke, said second member comprises a seat support, said third member comprises a base, said fourth member comprises a bearing guide, said main spring is compressed between a rear spring guide and a front spring guide when said yoke moves rearward, said front spring guide is attached to said bearing guide, said stop is fixedly attached to said yoke, said stop abuts against a top side of a stop slot formed into said base thereby restricting forward movement of said yoke and said stop abuts against a bottom side of said stop slot thereby restricting rearward movement of the yoke, and said assist spring is compressed between said base and said bearing guide when said yoke moves between an intermediate position and a reclined position.  
     
     
         20 . A chair comprising: a main spring biasing a back from a reclined position to an upright position and an assist spring biasing said back from said reclined position to an intermediate position.  
     
     
         21 . The chair according to  claim 20  wherein said assist spring is compressed between a non-moving face and a moving face that correspondingly moves as said main spring moves.  
     
     
         22 . The chair according to  claim 21  wherein said non-moving face defines a back face of a pocket formed into a base and said moving face defines a surface on a bearing guide slidably received in said pocket.  
     
     
         23 . The chair according to  claim 22  further comprising a spring guide compressing one end of said main spring, wherein said spring guide is fixedly attached to said bearing guide so that said corresponding movement between said moving face and said main spring is coextensive.  
     
     
         24 . The chair according to  claim 23  further comprising a mount attached to said moving face, wherein said assist spring is attached to said mount.  
     
     
         25 . The chair according to  claim 24  wherein said mount comprises an outer diameter that fits snugly within an inner diameter of said assist spring, a ramped tab within said outer diameter, and an undercut area below said ramped tab; said assist spring comprises a bent inward end that is received by said undercut area thereby locking the assist spring onto the mount.  
     
     
         26 . The chair according to  claim 20  wherein said assist spring is attached to a mount; said mount comprises an outer diameter that fits snugly within an inner diameter of said assist spring, a ramped tab within said outer diameter, an undercut area below said ramped tab; said assist spring comprises a bent inward end that is received by said undercut area thereby locking the assist spring onto the mount.  
     
     
         27 . A chair comprising: a seat a chair stem assembly attached to a bottom of said seat, a cylinder installed within said chair stem assembly comprising a valve pin moveable from side-to-side, and an actuating member having an interior cavity wherein said valve pin is received into said interior cavity.  
     
     
         28 . The chair according to  claim 27  further comprising an actuating stem engaging said actuating member.  
     
     
         29 . The chair according to  claim 28  wherein said interior cavity comprises a funnel-like interior cavity, said actuating member comprises a slot along an end of the actuating member opposite of said funnel-like interior cavity, said actuating stem comprises a smaller diameter nose and a larger diameter shoulder along one end of the actuating stem wherein the smaller diameter nose is received within said slot and said larger diameter shoulder abuts a side surface of the actuating member.  
     
     
         30 . The chair according to  claim 29  wherein said actuating member comprises a funnel-like exterior surface along the same end as said funnel-like interior cavity.  
     
     
         31 . The chair according to  claim 30  wherein said funnel-like exterior surface comprises an outer diameter that is approximately the size of an inner diameter of said chair stem assembly, wherein said outer diameter of said actuating member abuts against said. inner diameter of said chair stem assembly when said actuating stem engages the actuating member thereby forcing said valve pin to the side.  
     
     
         32 . The chair according to  claim 31  wherein said slot is positioned along a top of side of said actuating member and said funnel-like interior cavity and said exterior funnel-like surface are positioned along a bottom side of said actuating member.  
     
     
         33 . The chair according to  claim 32  wherein said actuating stem is disposed through a pressure adjustment knob, said actuating stem comprises a button that can be depressed by a user thereby engaging said actuating member, and said slot comprises a snap that retains said actuating stem.  
     
     
         34 . The chair according to  claim 27  wherein said actuating member comprises a funnel-like exterior surface along the same end as said interior cavity, said funnel-like exterior surface comprises an outer diameter that is approximately the size of an inner surface of said chair stem assembly, and said outer diameter of said actuating member abuts against said inner surface of said chair stem assembly when said actuating member is engaged thereby forcing said valve pin to the side.  
     
     
         35 . A chair comprising: a main spring biasing a back from a reclined position to an upright position and an assist spring biasing said back from said reclined position to an intermediate position, wherein said assist spring is a compression spring uncompressed from said upright position to said intermediate position and compressed from said intermediate position to said reclined position.  
     
     
         36 . The chair according to  claim 35  wherein said assist spring is compressed between a non-moving face and a moving face that correspondingly moves as said main spring moves.  
     
     
         37 . The chair according to  claim 36  wherein said non-moving face defines a back face of a pocket formed into a base and said moving face defines a surface on a bearing guide slidably received in said pocket.  
     
     
         38 . The chair according to  claim 37  further comprising a spring guide compressing one end of said main spring, wherein said spring guide is fixedly attached to said bearing guide so that said corresponding movement between said moving face and said main spring is coextensive.  
     
     
         39 . The chair according to  claim 38  further comprising a mount attached to said moving face, wherein said assist spring is attached to said mount.  
     
     
         40 . The chair according to  claim 39  wherein said mount comprises an outer diameter that fits snugly within an inner diameter of said assist spring, a ramped tab within said outer diameter, and an undercut area below said ramped tab; said assist spring comprises a bent inward end that is received by said undercut area thereby locking the assist spring onto the mount.  
     
     
         41 . The chair according to  claim 35  wherein said assist spring is attached to a mount; said mount comprises an outer diameter that fits snugly within an inner diameter of said assist spring, a ramped tab within said outer diameter, an undercut area below said ramped tab; said assist spring comprises a bent inward end that is received by said undercut area thereby locking the assist spring onto the mount.  
     
     
         42 . The chair according to  claim 35  further comprising a first member attached to said back; a second member comprising an axle pivotally attached to said first member; and a third member comprising a slot pivotally attached to said first member and pivotally and slidably attached to said second member, said axle of said second member being received in said slot of said third member, wherein said assist spring is disposed within said slot thereby being compressed by said axle.