Novel staircase design for space critical applications. This Spiral Staircase can be retracted when not in use. So we can save the space in the buildings for any other purpose. Large space which is normally required to construct a conventional staircase cannot be utilized for any other purpose. According to available data, a spiral staircase occupies 65-82% of the space normally required for an ‘L’ shaped staircase.

The objective of this invention is to construct a staircase, utilizing the minimum space, leaving the remaining space to be used for any other purpose. In this design, each stair that constitutes the assembly of the foldable staircase is in the shape of a sector whose narrow end is attached to a cylindrical ring which is placed onto a main solid rod one on top of the other to make it movable around this rod (axis). Each cylindrical ring has a groove at its top and a pin at its bottom, which draws the above step when the staircase is folded or unfolded. A programmed micro-controller governs the movement of the staircase through an electronic circuit. The power supply of the motor is controlled by a security password and an alarm indicates the folding and unfolding of staircase. Power from the electric motor installed under the floor level moves the lowermost step of the staircase by means of a belt. The movement of the motor clockwise and anticlockwise turns the lowermost step which draws the others in progress to fold or unfold the staircase. The contribution of the project by this novel design of staircase is to save about 90% of the space normally required by a conventional spiral staircase. This novel design could be used in space critical applications particularly in urban areas.

In a spiral staircase all the steps are arranged one top of another, around a vertical pole. By rotating all steps around the vertical main axis of a spiral staircase, it can be easily collapsed when it is not in use. So we devised a methodology which enables the rotation of each step individually around a main axis. This design enables to retract all steps into one side. Shape of a step should be triangular or a sector of a circle. Each step should be fixed to a hollow cylinder which goes around the main pole. When two adjacent steps are considered, one should be fixed as it could be rotated on top of the other on a horizontal plane around a vertical axis. The pin affixed to the lower edge of the next step goes through the upper groove of the hollow cylinder and when one cylinder moves, the other one follows it by the internal connecting system. When motor was turned clockwise, rotation was transmitted to sprocket wheel via chain. Then torque gets transmitted to the first step through the hard rubber plate which is located between the first step and the sprocket wheel.