Theatre Solution Lyric Auditorium Seating - Manual (Page 21)

20 Specifications Lyric Auditorium Seating
A. General: Fabricate theater seating with padding, fabric covering and injection-molded seat cover. Equip
each seat with a gravity self-rising mechanism so that unoccupied seats return to an upright position
perpendicular to the base line of floor of auditorium. Spring compensating mechanism will not be
acceptable. Chair profile with the seat in the upright position and without a tablet arm, cannot exceed 18”.
B. Seat Construction: Seat construction is comprised of an injection-molded polypropylene cover fastened
securely to an inner upholstered structural steel frame assembly. The outer seat cover shall have a
textured exterior surface and internal molded reinforcing ribs for a solid warp-free construction. The inner
seat frame assembly shall consist of a 7/8” dia. X 16 gauge steel tube formed with a waterfall front edge
and welded into a rigid assembly with (2) 11 gauge X 1” steel brackets and (1) 1/4” diameter steel rod. The
seat frame shall be fitted with a cast iron counterweight to insure automatic self-rising without the aid of
springs. A series of (7) 2” wide elastic suspension straps shall be stretched and woven in place and
fastened to the steel seat frame with 1/8” dia. steel hooks. Arch-spring and/or S-spring construction will not
be acceptable. A layer of 1 3/4” thick molded polyurethane foam shall be applied over the elastic webbing.
Foam shall be fire retardant and conform to the California Bureau of Home Furnishings Technical Bulletin
117. The upholstery cover shall be sewn and fitted to the seat assembly with collapsible assembly rings
and nylon tension cord.
The outer injection-molded seat cover and upholstered inner seat assembly shall be joined together with
cast aluminum mounting brackets. Seat widths of 19” and 21” shall be fitted with narrow style mounting
brackets. Seat widths of 20” and 22” shall be fitted with width-extending mounting brackets. The complete
seat assembly shall be assembled to the seat hinges using (2) special purpose M10 Hinge Bolts and (2)
special purpose M10 Hinge Pins which are specifically designed to accommodate installation tolerances.
C. Back Construction: Back construction is comprised of a curved plywood veneer outer panel fastened solidly
and without voids to an inner structural plywood panel. The outer panel shall be 9/16” thick, faced one side
with Grade A veneer centered across the width of the panel, and exposed plywood laminations along all
edges. The inner panel shall be 3/8” thick. Both shall be electronically glued hardwood plywood and shall
be fastened together with bayonet hanging brackets at the top and two #8 x 3/4” trim head screws at the
bottom, resulting in a rigid connection with no visible fasteners on the outer wood panel. The veneer face
and edges of the outer panel shall be stained to match the architect’s sample. The padding material shall
be 1-3/4” thick polyurethane foam (2-3/4” thick in the lumbar region), shall be glued to the inner panel and
shall conform to the California Bureau of Home Furnishings Technical Bulletin 117. The complete back
assembly shall be supported by two 13 gauge formed steel brackets and two 3/8-16 hex-head bolts and
shall be attached to the frame with (2) 1/4-20 machine screws.
D. Armrests: Shall be blow-molded of high density polyethylene and curved to match the leg mounting plate.
The armrest shall be fastened to the steel frame arm support with three #8 sheet metal screws.
E. Hinge: Shall be injection-molded of DuPont™ Zytel
®
801 nylon. The hinge shall be molded with
provisions to provide positive stop locations for the seat in both occupied and unoccupied positions. The
hinge shall be fitted with a plastic cover to eliminate all pinch points and shall include (2) 7/16” thick
urethane rubber pads to dampen noise upon the seat stop in both the vertical and horizontal positions.
Note: Dupont™ and Zytel ® are registered trademarks of E.I.du Pont de Nemours and Co. or its affiliates