Retractable sliding door

A retractable sliding door comprising:

• a door housing;
• a sliding door slidably mounted in said door housing;
• a retractable spring mechanism attached to said door housing along one side of said sliding door and having a spring drum having two laminated constant force retractable springs attached together and to said spring drum, said laminated constant force retractable springs being removably attached to a bracket attached to one side of said sliding door and adapted to retract an opened sliding door when said retractable spring is expanded by opening said sliding door, each said constant force spring being made of a spiral strip of steel which has been heat treated while coiled to a predetermined curvature so that when said strip of steel is extended, the stress in the steel resists the loading force at an approximate constant rate, so that said sliding door is opened against a generally constant force of the laminated spring and returns from an open to a closed position at a generally constant rate under the force of the constant force spring;
• and
• a cover housing attached to said door housing and covering said retractable spring mechanism.