Folding loft stair assembly

Abstract

A folding loft stair assembly has an outer mounting frame for mounting in a ceiling ope giving access to an attic space in a building. An inner stairway support frame is pivotally mounted on the outer frame for movement between a nested position within the outer frame and a downwardly extending in-use position. A two-art collapsible stairway is movable on the inner frame by a remotely controlled actuator between a raised collapsed stored position and lowered in-use position. The stairway includes an upper part and a lower part hingedly connected to the upper part. An upper end of the upper part is hingedly mounted on the inner frame. The lower part is slidably connected to the inner frame by a pair of slide arms. An inner end of each slide arm is pivotally connected to the inner frame and an outer end of the slide arm slidably engages a slide rail on the lower part.

1 . A folding loft stair assembly, including:
 an outer mounting frame for fixing in an associated ceiling ope,   an inner stairway support frame pivotally mounted on the outer frame for movement between a nested position within the outer frame and a downwardly extending in-use position,   a collapsible stairway mounted on the inner frame and movable between a collapsed stored position on the inner frame and an extended in-use position to provide access to said ceiling ope,   actuating means for controlled movement of the stairway between the collapsed stored position and the extended in-use position,   the stairway being a two-part stairway comprising an upper part attached to the inner frame and a lower part attached to the upper part, the two parts of the stairway being hingedly interconnected,   the upper part having an upper end hingedly attached to the inner frame,   the lower part being slidably connected to the inner frame by slide arms which slidably engage complementary slide rails on each side of the lower part of the stairway, said slide arms being pivotally mounted on the inner frame.   
     
     
         2 . The folding loft stair assembly as claimed in  claim 1 , wherein when in the collapsed stored position the stairway locates directly above the inner frame, within a boundary of the inner frame. 
     
     
         3 . The folding loft stair assembly as claimed in  claim 1 , wherein the inner frame is pivotally connected at one end by a hinge to the outer frame and a pair of folding support arms interconnect the inner and outer frames at each side spaced-apart from the hinge, each support arm being pivotally attached to each frame and being foldable intermediate each end to allow movement of the inner frame between the nested position on the outer frame and the extended in-use position. 
     
     
         4 . The folding loft stair assembly as claimed in  claim 1  wherein stairway bias means is provided for biasing the stairway into the folded stored position on the inner frame and stairway extension means is provided for moving the stairway into the extended position against said bias means. 
     
     
         5 . The folding loft stair assembly as claimed in  claim 4 , wherein the bias means comprises one or more gas struts mounted between the stairway and the inner frame. 
     
     
         6 . The folding loft stair assembly as claimed in  claim 4 , wherein the stairway extension means comprises a cable extended between the stairway and a cable winding drum and drum motor assembly on the inner frame. 
     
     
         7 . The folding loft stair assembly as claimed in  claim 1  wherein the actuating means is operable to control operation of said support arms. 
     
     
         8 . The folding loft stair assembly as claimed in  claim 1 , wherein the actuating means includes an actuator mounted between the outer frame and a support arm, said actuator having means for pivoting the support arm on the outer frame. 
     
     
         9 . The folding loft stair assembly as claimed in  claim 1 , wherein means is provided to counterbalance the weight of the inner frame and stairway. 
     
     
         10 . The folding loft stair assembly as claimed in  claim 9 , wherein said counterbalance means comprises a number of gas struts mounted between the outer frame and the support arms. 
     
     
         11 . The folding loft stair assembly as claimed in  claim 1  wherein the upper part and the lower part of the stairway each comprise a pair of parallel spaced-apart stringers interconnected by spaced-apart steps, the depth of each step being greater than the width of the stringers, each step projecting outwardly of the stringers. 
     
     
         12 . The folding loft stair assembly as claimed in  claim 1  wherein the actuating means includes first control means for controlling pivoting of the inner frame on the outer frame and second control means for controlling movement of the stairway between the collapsed position and the extended position. 
     
     
         13 . The folding loft stair assembly as claimed in  claim 12  wherein the first control means comprises a telescopic actuator mounted between the outer frame and a folding support arm, the telescopic actuator being pivotally mounted on the outer frame and on the support arm, the actuator having a rod which is operable to extend and retract to pivot the arm, the rod being connected to a leadscrew operable by an electric motor to move the rod. 
     
     
         14 . The folding loft stair assembly as claimed in  claim 12  wherein the second control means comprises an electric motor drivably connected to a cable winding drum to which a cable is attached, the cable having a first end attached to the drum and a second end attached to a lower end of the upper stairway part, said second control means further including telescopic struts each having a first end pivotally connected to the inner frame and a second end pivotally connected to the upper stairway part, said struts biasing the upper stairway part towards the folded stored position on the inner frame. 
     
     
         15 . The folding loft stair assembly as claimed in  claim 1  wherein a remote control means is provided for controlling operation of the actuating means.