Swingable chair back with top pivot

A chair comprising:

• an upright back including upper and lower ends;
• a frame including laterally spaced first and second rigid uprights positioned adjacent opposite sides of said back;
• a seat attached to said frame adjacent said lower end of said back;
• a pivot assembly coupling said first and second uprights to said back for permitting pivoting of said back about a substantially horizontal pivot axis which projects laterally of said back and is positioned in the vicinity of said upper end of said back;
• a spring arrangement that exerts a force on said back a substantial distance below said pivot axis for biasing said back toward a forward position;
• said spring arrangement including at least one coil spring which has one spring leg that is engaged with said back near a midpoint between said upper and lower ends thereof;
• and
• said spring arrangement including a second leg acting against an elongate lever arm at a location spaced downwardly from said pivot axis to bias said back toward said forward position.

A chair comprising:

• an upright back member including upper and lower ends;
• a frame including laterally spaced first and second rigid uprights positioned adjacent opposite sides of said back member;
• a seat attached to said frame adjacent said lower end of said back member;
• a pivot assembly coupling said first and second uprights to said back for permitting pivoting of said back member about a substantially horizontal pivot axis which projects laterally of said back and is positioned in the vicinity of said upper end of said back member;
• said pivot assembly including a transverse shaft which is fixed to said frame and includes pivot shaft parts which are positioned adjacent opposite sides of the back member and extend generally along the pivot axis for fixed securement to said uprights adjacent upper ends thereof, and a pair of bearing journal parts fixed to said back member adjacent opposite sides thereof in the vicinity of said upper end and disposed in rotative supportive engagement with the respective pivot shaft parts;
• said transverse shaft having a center shaft part which is positioned adjacent said back member and projects downwardly a substantial distance away from said pivot axis to a location at least approximately midway between the upper and lower ends of the back member;
• said center shaft part having a generally upwardly-oriented U-shaped configuration defined by a lower shaft segment which is generally parallel with but displaced vertically downwardly a substantial distance below said pivot axis and a pair of upright shaft segments which at lower ends join to opposite ends of said center shaft segment and which at upper ends join to inner ends of the respective pivot shaft parts with the latter having outer ends thereof fixedly joined to the respective uprights;
• and
• a stop arrangement cooperating between said back member and said center shaft part for restricting rearward swinging of said back member about said pivot axis to a rear position.

A chair comprising:

• an upright back member including upper and lower ends;
• a frame including laterally spaced first and second rigid uprights positioned adjacent opposite sides of said back member;
• a seat attached to said frame adjacent said lower end of said back member;
• a pivot assembly coupling said first and second uprights to said back for permitting pivoting of said back member about a substantially horizontal pivot axis which projects laterally of said back and is positioned in the vicinity of said upper end of said back member;
• said pivot assembly including a transverse shaft which is fixed to said frame and includes pivot shaft parts which are positioned adjacent opposite sides of the back member and extend generally along the pivot axis for fixed securement to said uprights adjacent upper ends thereof, and a pair of bearing journal parts fixed to said back member adjacent opposite sides thereof in the vicinity of said upper end and disposed in rotative supportive engagement with the respective pivot shaft parts;
• said transverse shaft having a center shaft part which is positioned adjacent said back member and projects downwardly a substantial distance away from said pivot axis to a location at least approximately midway between the upper and lower ends of the back member;
• said transverse shaft including said pivot shaft parts and said center shaft part being formed from a one-piece monolithic cylindrical rod member;
• and
• a stop arrangement cooperating between said back member and said center shaft part for restricting rearward swinging of said back member about said pivot axis to a rear position.

A chair comprising:

• an upright back arrangement having upper and lower edges, said back arrangement including an upright structural back member and an outer rear cover which overlies a rear side of said back member and is secured thereto and defines a small interior space therebetween;
• a frame including laterally spaced first and second rigid uprights positioned adjacent opposite sides of said back arrangement, said first and second uprights being positioned exteriorly of said back arrangement and having upper ends positioned adjacent opposite upper corners of said back arrangement;
• a seat attached to said frame adjacent said lower edge of said back;
• a pivot assembly positioned within said interior space and coupling said first and second uprights to said back arrangement for permitting pivoting of said back arrangement about a substantially horizontal pivot axis which projects laterally of said back arrangement adjacent said upper edge thereof;
• said pivot assembly including a transverse pivot shaft arrangement having parts positioned adjacent opposite upper corners of the back member so as to extend generally along the pivot axis and fixed to said uprights adjacent the upper ends thereof, and a pair of bearing journal parts fixed to said back member adjacent opposite upper corners thereof and disposed in rotative supportive engagement with the respective pivot shaft parts;
• an elongate arm fixed to said transverse shaft arrangement and positioned within said interior space adjacent from said pivot axis to a location wherein a back member, said arm projecting downwardly a substantial part of said arm is positioned approximately midway between the upper and lower edges of the back arrangement;
• and
• a spring biasing structure disposed within said interior space and cooperating between said lower end part of said arm and said back member for normally urging said back arrangement to swing about said pivot axis forwardly toward a forward position, said spring biasing structure exerting a biasing force against said back member at a location positioned downwardly a substantial distance below said pivot axis.