sofa simple mechanism:

Specification:

1. The ottoman adopts the design of wide heavy gauge links and built-in
     articulating  elevated  mid-ottoman. Profile shape designed for safety
     and appearance  without pinch points.Articulating designs allows use
     of wider&higher mid-ottoman for elimination of entrapment areas and
     for leg support.
 2. The system adopts the geometrically engineering theory. The occupant
     can  change   from  the sitting  position  to reclining   position  at any
     position as  he  wants  to.  Occupant  is  weight is  used  to  balance
     operation  and to make the  mechanism  extending or  retracting  to
     ensure the occupant is safety and comfort.
 3. The system  uses locking  devices on  both side brackets. It enables
     maximum   synchronization  of  side  positive locking  of  both sides.
     Ottoman is locked closed on both sides
 4. The system uses the extended life rivet joints design. All rivet joints
     have  either  acetal or  bronze  rivet bushing and  acetal spacers to
     eliminate any steel to steel contact. No  metal to metal noises when
     links contact nylon stop pins.