Lift ladder

Abstract

A lift ladder has a support frame with two support bars each having a U-shaped portion and a vertical support portion. A transverse bar is disposed between the two supporting bars at the vertical support portion. The transverse bar has a catch member. A guide member is provided at an end of the vertical support portion of each of the support bars. The guide member is formed with a cutout. A ladder body to be supported by the support frame includes two vertical support members each to be slidably guided by a respective guide member. Rungs operatively engage with the catch member to fix the ladder in a position. A locking member is formed on each of the two vertical support members. The locking member is shaped to fit into the cutout of the guide member for minimizing movement of the ladder body with respect to the support frame.

1 . A lift ladder, comprising: 
 a support frame having two support bars, each of said support bars having: 
 a U-shaped portion; and  
 a vertical support portion having an end;  
   a transverse bar disposed between said two support bars at said vertical support portion, said transverse bar having a catch;    guide members provided at said end of said vertical support portion of each of said support bars, at least one of said guide members defining a cutout; and    a ladder body movably supported by said support frame, said ladder body having: 
 two vertical support members each slidably guided by a respective one of said guide members;  
 rungs each releasably engaged with said catch for setting a vertical position of said ladder body with respect to said support frame; and  
 a locking member formed on at least one of said two vertical support members, said locking member shaped to fit into said cutout for reducing movement of said ladder body with respect to said support frame.  
   
   
   
       2 . The lift ladder according to  claim 1 , wherein: 
 each of said guide members define a cutout; and    a locking member is formed on each of said two vertical support members, said locking members each shaped to fit into said cutout.    
   
   
       3 . The lift ladder according to  claim 1 , wherein said locking member reduces lateral movement of said ladder body with respect to said support frame when disposed in said cutout.  
   
   
       4 . The lift ladder according to  claim 1 , wherein: 
 said support frame has a longitudinal extent; and    said locking member reduces movement of said ladder body in a direction orthogonal to said longitudinal extent when disposed in said cutout.    
   
   
       5 . The lift ladder according to  claim 1 , wherein: 
 said ladder body has an end; and    said locking member is disposed on said vertical support member from a second uppermost one of said rungs to said end of said ladder body.    
   
   
       6 . The lift ladder according to  claim 5 , wherein said locking member is disposed on said vertical support member substantially at said second uppermost rung.  
   
   
       7 . The lift ladder according to  claim 2 , wherein: 
 said ladder body has an end; and    said locking members are disposed on a respective one of said vertical support members from a second uppermost one of said rungs to said end of said ladder body.    
   
   
       8 . The lift ladder according to  claim 7 , wherein said locking members are disposed on a respective one of said vertical support members substantially at a location of said second uppermost rung.  
   
   
       9 . The lift ladder according to  claim 1 , wherein: 
 said catch has a L-shape;    said rungs have a ceiling and two sides in an upside-down U-shape; and    one of said sides operatively connects with said catch to releasably fix said ladder body in a position.    
   
   
       10 . The lift ladder according to  claim 1 , further comprising a cable for connecting a respective one of said vertical support members of said ladder body to a respective one of said support bars.  
   
   
       11 . A lift ladder, comprising: 
 a ladder body having rungs and a locking member;    a support frame slidably supporting said ladder body and having: 
 a guide member for guiding said ladder body between a stowed position and at least one extended position; and  
 a catch releasably engaging one of said rungs in at least one of said stowed position and said at least one extended position; and  
   said locking member operatively connecting said guide member and locking said ladder body said at least one extended position.    
   
   
       12 . The lift ladder according to  claim 11 , wherein said support frame has a transverse bar and said catch is formed on said transverse bar.  
   
   
       13 . The lift ladder according to  claim 12 , wherein: 
 said guide member defines a cutout; and    said locking member fits into said cutout for minimizing movement of said ladder body with respect to said support frame.    
   
   
       14 . The lift ladder according to  claim 11 , wherein: 
 said guide member is two guide members each defining a cutout; and    said locking member is two locking members each shaped to fit into said cutout.    
   
   
       15 . The lift ladder according to  claim 11 , wherein said locking member reduces lateral movement of said ladder body with respect to said support frame when disposed in said cutout.  
   
   
       16 . The lift ladder according to  claim 11 , wherein: 
 said support frame has a longitudinal extent; and    said locking member reduces movement of said ladder body in a direction orthogonal to said longitudinal extent when disposed in said cutout.    
   
   
       17 . The lift ladder according to  claim 11 , wherein: 
 said ladder body has an end; and    said locking member is disposed on said ladder body from a second uppermost one of said rungs to said end of said ladder body.    
   
   
       18 . The lift ladder according to  claim 11 , wherein: 
 said catch is L-shaped;    said rungs have a ceiling and two sides in an upside-down U-shape; and    one of said sides operatively connects with said catch to releasably fix said ladder body in at least one of said stowed position and said at least one extended position.    
   
   
       19 . A lift ladder, comprising: 
 a support frame having: 
 two substantially vertically oriented hand rails having a lower portion; and  
 a transverse bar fixedly connecting said two hand rails to one another, said transverse bar having a catch;  
   at least one guide member provided at said lower portion of at least one of said hand rails, said at least one guide member defining a cutout; and    a ladder body movably supported by said support frame, said ladder body having: 
 rungs each releasably engaged with said catch for setting a position of said ladder body with respect to said support frame; and  
 a locking member formed on at least one said two vertical support members, said locking member shaped to fit into said cutout for reducing movement of said ladder body.  
   
   
   
       20 . The lift ladder according to  claim 19 , wherein: 
 said at least one guide member is two guide member each defining a cutout;    a locking member is two locking members formed on each of said two hand rails; and    said locking members are each shaped to fit into said cutout.    
   
   
       21 . The lift ladder according to  claim 19 , wherein said locking member reduces lateral movement of said ladder body with respect to said support frame when disposed in said cutout.  
   
   
       22 . The lift ladder according to  claim 19 , wherein: 
 said support frame has a longitudinal extent; and    said locking member reduces movement of said ladder body in a direction orthogonal to said longitudinal extent when disposed in said cutout.    
   
   
       23 . The lift ladder according to  claim 19 , wherein: 
 said ladder body has an end; and    said locking member is disposed on said ladder body from a second uppermost one of said rungs to said end of said ladder body.    
   
   
       24 . The lift ladder according to  claim 23 , wherein said locking member is disposed on said ladder body substantially at said second uppermost rung.  
   
   
       25 . The lift ladder according to  claim 19 , wherein: 
 said catch has a L-shape;    said rungs have a ceiling and two sides in an upside-down U-shape; and    one of said sides operatively connects with said catch to releasably fix said ladder body in a position.    
   
   
       26 . The lift ladder according to  claim 19 , further comprising a cable for connecting a respective one of said vertical support members of said ladder body to a respective one of said support bars.