Dual torsion bar chair control

Claim 2

In a chair control having a tiltable member tiltably mounted to a stationary member, a first torsion bar operably connected at a first end to said tiltable member, said first end being fixed against rotation with respect thereto, a second torsion bar operably connected at a first end to said stationary member, said first end being fixed against rotation with respect thereto, and means interconnecting said first and second bars at a point spaced from said first ends thereof for transmitting the rotation of one of said bars to the other, the improvement comprising: said torsion bars having their second ends mounted in said interconnecting means, said interconnecting means being free of connection with said tiltable member and said stationary member.

Claim 3

The chair control of claim 1 in which each of said bars is generally U-shaped in configuration, including first and second legs and a base; a pocket in each of said tiltable and stationary members respectively for receiving said first legs of said first and second torsion bars respectively; said interconnecting means operably connecting said second legs of said torsion bars.

Claim 4

The chair control of claim 2 in which said torsion bars are generally circular in cross section.

Claim 5

The chair control of claim 3 in which said intErconnecting means comprises a generally channel-shaped bracket having sidewalls and a bottom; said sidewalls embracing said second legs of said torsion bars, each of said second legs extending inwardly towards the other, from an end of said channel-shaped bracket; each of said second legs contacting said bottom at a respective fulcrum point; said bottom sloping downwardly from said fulcrum point, towards the center of said bracket; an adjustment means extending upwardly from the center of said bottom, passing between the ends of said second legs, and overlying the tops of said second legs for holding said second legs against said fulcrum points and for facilitating the adjustment of pretension on said torsion bars.

Claim 6

The chair control of claim 4 in which said adjustment means comprises a generally T-shaped nut, having a stem and a crossbar, threaded on a bolt; said bolt extending upwardly through an aperture in said bottom of said bracket; said crossbar of said nut overlying said second legs.

Claim 7

The chair control of claim 5 in which said crossbar includes a downwardly projecting hook at each end thereof; each of said second legs including a recess in the top surface thereof for matingly receiving said hooks.

Claim 8

In a chair control having a tiltable member tiltably mounted to a stationary member, the improvement comprising: a torsion rod operably connected to said stationary member and to said tiltable member for generating torque therebetween, about the longitudinal axis of said torsion rod, when said tiltable member is tilted; a resilient bending means operably connected in series with said torsion rod, between said tiltable member and said stationary member, said bending means being sufficiently bendable relative to the torque generated in said torsion rod that a flatter spring curve can be obtained with a more compact torsion rod.

Claim 9

In a chair control having a tiltable member tiltably mounted to a stationary member, the improvement comprising: a torsion rod operably connected to said stationary member and to said tiltable member for generating torque therebetween, about the longitudinal axis of said torsion rod, when said tiltable member is tilted; a resilient bending means operably connected in series with said torsion rod, between said tiltable member and said stationary member, said bending means being sufficiently bendable relative to the torque generated in said torsion rod that a flatter spring curve can be obtained with a more compact torsion rod.

Claim 10

In a chair control having a tiltable member tiltably mounted to a stationary member, the improvement comprising: a torsion means operably connected to said stationary member and to said tiltable member for generating torque therebetween when said tiltable member is tilted; a resilient bending means operably connected in series with said torsion means, between said tiltable member and said stationary member, whereby a flatter spring curve can be obtained with a more compact torsion means; said torsion means and said resilient bending means both comprising a torsion rod having at least one bend therein; one end of said torsion bar being fixed against rotation with respect to said stationary member; said torsion bar extending from said one end generally parallel to the axis about which said tiltable member tilts; said torsion bar including a leg extending from said bend in a direction generally perpendicular to said axis of tilting; means operably connecting said leg to said tiltable member whereby said tilting bends said leg and simultaneously twists that portion of said torsion bar which is parallel to said tilting axis; said leg having a substantial length relative to the length of said bar from said one end to said bend whereby said bending of said leg is sufficient relative to said twisting of said bar to give said chair control a flatter spring curve with a more compact torsion bar.

Claim 11

In a chair control having a tiltable member tiltably mounted to a stationary member, the improvement comprising: a torsion means operably connected to said stationary member and to said tiltable member for generating torque therebetween when said tiltable member is tilted; a resilient bending means operably connected in series with said torsion means, between said tiltable member and said stationary member, whereby a flatter spring curve can be obtained with a more compact torsion means; said torsion means and said resilient bending means both comprising a torsion rod having at least one bend therein; one end of said torsion bar being fixed against rotation with respect to said stationary member; said torsion bar extending from said one end generally parallel to the axis about which said tiltable member tilts; said torsion bar including a leg extending from said bend in a direction generally perpendicular to said axis of tilting; means operably connecting said leg to said tiltable member whereby said tilting bends said leg and simultaneously twists that portion of said torsion bar which is parallel to said tilting axis; said leg having a substantial length relative to the length of said bar from said one end to said bend whereby said bending of said leg is sufficient relative to said twisting of said bar to give said chair control a flatter spring curve with a more compact torsion bar.

Claim 12

The chair control of claim 8 in which said operable connecting means comprises a first means engaging the upper surface of the end of said leg and a second means engaging the under surface of said leg at a point closely adjacent said bend whereby said leg tends to bend between said first engaging means and said second engaging means.

Claim 13

The chair control of claim 9 in which two such torsion bars are provided, the first of said torsion bars having one end fixed against rotation with respect to said stationary member and the second having one end fixed against rotation with respect to said tiltable member; each of said torsion bars including said bend and said leg; said operable connecting means comprising a means interconnecting bOth said legs whereby the rotation of one of said rods is transmitted to the other.

Claim 14

In a chair control having a tiltable member tiltably mounted on a stationary member, a first torsion means operably connected at a first end to said tiltable member, said first end being fixed against rotational movement with respect to said tiltable member, a second torsion means operably connected at a first end to said stationary member, said first end being fixed against rotation with respect, to said stationary member, and means interconnecting said first and second torsion means at a point spaced from said fixed ends thereof for transmitting the rotation of one to the other, the improvement comprising: at least one of said first and second torsion means being capable of resilient bending movement as well as torsional movement; at least one of said first and second torsion means being free to bend with respect to said stationary and tiltable members, and said interconnecting means being sufficiently rigid that tilting of said tiltable member results in bending of said one torsion means as well as simultaneously twisting of both said torsion means.

Claim 15

In a chair control having a tiltable member tiltably mounted on a stationary member, a first torsion means operably connected at a first end to said tiltable member, said first end being fixed against rotational movement with respect to said tiltable member, a second torsion means operably connected at a first end to said stationary member, said first end being fixed against rotation with respect, to said stationary member, and means interconnecting said first and second torsion means at a point spaced from said fixed ends thereof for transmitting the rotation of one to the other, the improvement comprising: at least one of said first and second torsion means being capable of resilient bending movement as well as torsional movement; at least one of said first and second torsion means being free to bend with respect to said stationary and tiltable members, and said interconnecting means being sufficiently rigid that tilting of said tiltable member results in bending of said one torsion means as well as simultaneously twisting of both said torsion means.

Claim 16

The chair control of claim 11 in which both of said torsion bars are free to bend with respect to said stationary and tiltable members.

Claim 17

The chair control of claim 12 in which each of said bars is generally U-shaped in configuration, including first and second legs and a base; a pocket in each of said tiltable and stationary members respectively for receiving said first legs of said first and second torsion bars respectively; said interconnecting means operably connecting said second legs of said torsion bars.

Claim 18

The chair control of claim 13 in which said torsion bars are generally circular in cross section.

Claim 19

The chair control of claim 14 in which said interconnecting means comprises a generally channel-shaped bracket having sidewalls and a bottom; said sidewalls embracing said second legs of said torsion bars, each of said second legs extending inwardly towards the other, from an end of said channel-shaped bracket; each of said second legs contacting said bottom at a respective fulcrum point; said bottom sloping downwardly from said fulcrum point, towards the center of said bracket; an adjustment means extending upwardly from the center of said bottom, passing between the ends of said second legs, and overlying the tops of said second legs for holding said second legs against said fulcrum points and for facilitating the adjustment of pretension on said torsion bars; said adjustment means comprising a generally T-shaped nut, having a stem and a crossbar, threaded on a bolt; said bolt extending upwardly through an aperture in said bottom of said bracket; said crossbar of said nut overlying said second legs; said crossbar including a downwardly projecting hook at each end thereof; each of said second legs including a recess in the top surface thereof for matingly receiving said hooks.

Claim 20

In a chair control having a tiltable member tiltably mounted to a stationary member, and first and second torsion bars, the improvement comprising: each of said first and second torsion bars being generally U-shaped, having a first leg, a second leg and a base; means in said stationary member for fixedly receiving said first leg of said first torsion bar and means in said tiltable member for fixedly receiving said first leg of said second torsion bar; said bases of said torsion bars extending from said receiving means generally parallel to the axis about which said tiltable member tilts; said second legs of said first and second torsion bars extending inwardly towards one another; interconnecting means embracing said second legs for transmitting the rotation of one of said bars to the other.

Claim 21

In a chair control having a tiltable member tiltably mounted to a stationary member, and first and second torsion bars, the improvement comprising: each of said first and second torsion bars being generally U-shaped, having a first leg, a second leg and a base; means in said stationary member for fixedly receiving said first leg of said first torsion bar and means in said tiltable member for fixedly receiving said first leg of said second torsion bar; said bases of said torsion bars extending from said receiving means generally parallel to the axis about which said tiltable member tilts; said second legs of said first and second torsion bars extending inwardly towards one another; interconnecting means embracing said second legs for transmitting the rotation of one of said bars to the other.

Claim 22

The chair control of claim 16 in which said interconnecting means is free of any fixed connection with said stationary and tiltable members.

Claim 23

The chair of claim 16 in which each said receiving means comprises a pocket embrAcing said first leg.

Claim 24

The chair control of claim 18 in which said torsion bars are generally circular in cross section.

Claim 25

The chair control of claim 16 in which said torsion bars are generally circular in cross section.

Claim 26

The chair control of claim 20 in which said interconnecting means comprises a generally channel-shaped bracket having sidewalls and a bottom; said sidewalls embracing said second legs of said torsion bars, each of said second legs extending inwardly towards the other, from an end of said channel-shaped bracket; each of said second legs contacting said bottom at a respective fulcrum point; said bottom sloping downwardly from said fulcrum point, towards the center of said bracket; an adjustment means extending upwardly from the center of said bottom, passing between the ends of said second legs, and overlying the tops of said second legs for holding said second legs against said fulcrum points and for facilitating the adjustment of pretension on said torsion bars; said adjustment means comprising a generally T-shaped nut, having a stem and a crossbar, threaded on a bolt; said bolt extending upwardly through an aperture in said bottom of said bracket; said crossbar of said nut overlying said second legs.

Claim 27

The chair control of claim 21 in which said stationary and tiltable members include apertures in the bottom thereof; the head of said bolt being accessible through said apertures.

Claim 28

The chair control of claim 22 in which said crossbar includes a downwardly projecting hook at each end thereof; each of said second legs including a recess in the top surfaces thereof for matingly receiving said hooks.

Claim 29

The control of claim 16 in which said interconnecting means comprises: first means engaging the end of each said second leg on one surface thereof; second means engaging the opposite surface at each of said second legs at a point near its juncture with said base.