Telescoping stairway for accessing attic storage space

Abstract

A stairway for use in an opening formed between an attic and a floor below comprises a frame adapted to fixedly engage the opening and a plurality of stairway sections operatively coupled to the frame. The stairway sections each have a pair of rails and a plurality of steps coupled between the respective rails. The rails further comprise respective upper and lower edge surfaces having corresponding shapes to permit nesting engagement of the stairway sections on top of each other and relative parallel movement of the stairway sections with respect to each other. Successive ones of the stairway sections are operatively coupled to each other such that they remain nested while being moved relative to each other. Upon reaching an extent of travel relative to each other, orientation of the successive ones of the stairway sections changes to a substantially contiguous and axially aligned structure in which the successive stairway sections are linked end-to-end to provide a continuous stairway. One or more locking pins may be adapted to lock the successive stairway sections in an end-to-end configuration.

1 . A stairway for use in an opening formed between an attic and a floor below, comprising: 
 a frame adapted to fixedly engage the opening;    a plurality of stairway sections operatively coupled to the frame and each having a pair of rails and a plurality of steps coupled between the respective rails, the rails further comprising respective upper and lower edge surfaces having corresponding shapes to permit nesting engagement of the stairway sections on top of each other and relative parallel movement of the stairway sections with respect to each other;    wherein, successive ones of the stairway sections are operatively coupled to each other such that they remain nested while being moved relative to each other, and upon reaching an extent of travel relative to each other, orientation of the successive ones of the stairway sections changes to a substantially contiguous and axially aligned structure in which the successive stairway sections are linked end-to-end to provide a continuous stairway.    
   
   
       2 . The stairway of  claim 1 , wherein the rails of at least one of the stairway sections further include a slot extending substantially an entire length of each associated one of the rails.  
   
   
       3 . The stairway of  claim 2 , further comprising a slide block adapted to travel within the slot of a corresponding one of the rails, and a pair of parallel linkages coupled between the slide block and a corresponding one of the rails of a successive one of the stairway sections, the parallel linkages being oriented in a first direction when the successive stairway sections are nested relative to each other and in a second, substantially perpendicular, direction when the successive stairway sections are joined.  
   
   
       4 . The stairway of  claim 3 , wherein the pair of parallel linkages are vertically offset with respect to each other.  
   
   
       5 . The stairway of  claim 3 , further comprising at least one locking pin adapted to lock at least one of the parallel linkages in the second direction.  
   
   
       6 . The stairway of  claim 3 , wherein the slide block further comprises at least one roller adapted to engage the slot to facilitate low friction movement of the slide block within the slot.  
   
   
       7 . The stairway of  claim 1 , further comprising a door hingedly attached to the frame, at least a first one of the stairway sections being fixedly coupled to the door.  
   
   
       8 . The stairway of  claim 7 , further comprising a locking finger operatively coupled to the frame and oriented to engage a corresponding opening of the door to thereby lock the door in a closed position when the stairway sections are stowed.  
   
   
       9 . The stairway of  claim 8 , further comprising a manual release lever adapted to disengage the locking finger from the opening.  
   
   
       10 . The stairway of  claim 8 , further comprising a release cable adapted to disengage the locking finger from the opening upon deployment of the stairway sections.  
   
   
       11 . The stairway of  claim 7 , further comprising a pivot joint coupling the rails of the first one of the stairway sections to the door, the pivot joint permitting the rails of the stairway sections to be folded parallel to the door to provide a compact profile.  
   
   
       12 . The stairway of  claim 1 , wherein the steps are selectively detachable from the rails.  
   
   
       13 . The stairway of  claim 1 , further comprising at least one slider rail coupled to the first one of the stairway sections, the frame further comprising a pivot point that slidably engages the at least one slider rail, wherein the slider rail defines a range of motion of the plurality of stairway sections in pivoting from a substantially horizontal stowed orientation to a deployed orientation disposed at a predetermined angle from horizontal.  
   
   
       14 . The stairway of  claim 13 , wherein the at least one slider rail further comprises an end stop defining a limit of travel of the slider rail with respect to the pivot point.  
   
   
       15 . The stairway of  claim 14 , wherein the at least one slider rail further comprises a temporary stop prior to the end stop defining an initial angle for deployment of the stairway sections prior to coming into contact with the floor.  
   
   
       16 . The stairway of  claim 1 , further comprising at least one deployment cable associated with each rail of the plurality of stairway sections, the at least one deployment cable controlling relative movement of the plurality of stairway sections such that relative movement in a stairway deployment direction is provided by paying out the at least one deployment cable and relative movement in a stairway stowing direction is provided by retracting the at least one deployment cable.  
   
   
       17 . The stairway of  claim 16 , further comprising a rotatable drive screw carrying at least one pulley engaged with the at least one deployment cable, wherein rotation of the drive screw in a first direction provides paying out of the at least one deployment cable and rotation of the drive screw in a second direction provides retraction of the at least one deployment cable.  
   
   
       18 . The stairway of  claim 17 , further comprising an electric motor operatively coupled to the drive screw to enable powered rotation of the drive screw in selected ones of the first and second directions.  
   
   
       19 . The stairway of  claim 18 , wherein the electric motor and the drive screw are coupled to the frame.  
   
   
       20 . The stairway of  claim 18 , wherein the electric motor and the drive screw are disposed within at least one of the plurality of stairway sections.  
   
   
       21 . The stairway of  claim 17 , further comprising a removable crank adapted to be operatively coupled to the drive screw to enable manual rotation of the drive screw in selected ones of the first and second directions.  
   
   
       22 . The stairway of  claim 17 , further comprising a pull rope operatively coupled to the drive screw to enable manual rotation of the drive screw in selected ones of the first and second directions.  
   
   
       23 . The stairway of  claim 22 , wherein the pull rope is adapted to retract when not in use.  
   
   
       24 . The stairway of  claim 23 , further comprising a removable hook adapted to retrieve the pull rope when retracted.  
   
   
       25 . The stairway of  claim 17 , further comprising a control circuit adapted to control operation of the electric motor.  
   
   
       26 . The stairway of  claim 25 , wherein the control circuit includes at least one micro-switch adapted to sense a deployment condition of at least one of the stairway sections.  
   
   
       27 . The stairway of  claim 1 , wherein the plurality of stairway sections further comprises at least three stairway sections.  
   
   
       28 . The stairway of  claim 1 , wherein the plurality of stairway sections further comprises at least two stairway sections.  
   
   
       29 . The stairway of  claim 1 , further comprising at least one locking pin adapted to lock the successive stairway sections in an end-to-end configuration.  
   
   
       30 . The stairway of  claim 1 , wherein the upper edge surfaces of the plurality of stairway sections further comprises a generally convex rounded shape, and the lower edge surfaces of the plurality of stairway sections further comprises a generally concave rounded shaped adapted to nest with the generally convex rounded shape of the upper edge surfaces.  
   
   
       31 . The stairway of  claim 1 , wherein the lower edge surfaces of at least one of the plurality of stairway sections further comprises at least one roller adapted to enable low friction sliding engagement between successive ones of the stairway sections.  
   
   
       32 . The stairway of  claim 1 , further comprising at least one handrail coupled to at least one of the plurality of stairway sections.  
   
   
       33 . The stairway of  claim 1 , wherein one of the plurality of stairway sections adapted to come into contact with the floor further comprises an adjustable foot.