Retractable sofa bed with hidden mattress platform and guide stop with improved security

Abstract

A sofa bed with a seat back assembly, seat, side frame assembly and lock and release member. The side frame assembly includes a side frame and a link assembly connected to the side frame. The link assembly moves between a first position and a second position to allow for conversion of the sofa bed between a sofa position and a bed position. The lock and release mechanism locks the link assembly in place.

What is claimed is: 
     
         1 . A side frame assembly for a sofa bed comprising:
 a side frame; and   a link assembly connected to the side frame in a manner so as to allow the link assembly to move between a first position and a second position; and   a lock and release mechanism locking the link assembly in place when the link assembly is in the first position.   
     
     
         2 . The side frame assembly of  claim 1 , wherein:
 the side frame comprises a guide;   the link assembly comprises a bearing connection connecting the link assembly to the guide,   the bearing connection slides along the guide to which the link assembly is connected when the link assembly moves between the first position and the second position, and   the lock and release mechanism is attached to the side frame adjacent to the guide, such that the lock and release mechanism receives the bearing connection and locks the bearing connection in place when the link assembly is in the first position.   
     
     
         3 . The side frame assembly of  claim 2 , wherein the lock and release mechanism comprises:
 a lock arm which is sized and shaped to receive the bearing connection, the lock arm receiving the bearing connection and locking the bearing connection in place when the link assembly is moved to the first position;   a spring biasing the lock and release mechanism in a locked position; and   a release arm to which a release cable is attached, wherein pulling the release cable pulls the release arm extending the spring and moving the lock and release mechanism from the closed position to an open position.   
     
     
         4 . The side frame assembly of  claim 3 , wherein the release arm comprises a contact surface and a lock groove, wherein the contact surface is angled towards the lock groove such that the lock and release mechanism is forced open upon application of sufficient force to the contact surface. 
     
     
         5 . The side frame assembly of  claim 1 , wherein:
 the link assembly comprises:
 a seat link member connected to the side frame; 
 a crank member connected to the side frame and pivotally connected to the seat link member; and 
   the lock and release mechanism comprises:
 a lever attached to the crank member, the lever comprising a mating projection, wherein the mating projection mates with a notch formed in the seat link member so as to lock the link assembly in the first position. 
   
     
     
         6 . The side frame assembly of  claim 1 , wherein the link assembly comprises:
 a seat link member comprising a first bearing connection connecting the seat link member to the side frame; and   a crank member comprising a main pivot, an arm and a leg, wherein the leg is pivotally attached to the seat link member, and the arm includes a second bearing connection connecting the crank member to the side frame;   wherein the side frame comprises:   a pivot slot to which the main pivot is pivotally connected;   a diagonal guide formed in the side frame, wherein the first bearing connection is slidably connected to the diagonal guide;   an arcuate guide formed in the side frame to the rear of the diagonal guide, wherein the second bearing connection is slidably connected to the arcuate guide.   
     
     
         7 . The side frame assembly of  claim 6 , wherein the arcuate guide includes a lower end and an upper end, and the second bearing connection slides between the lower end and the upper end, and
 the lock and release mechanism is attached to the side frame at a position adjacent to the lower end.   
     
     
         8 . The side frame assembly of  claim 7 , wherein the lock and release mechanism comprises:
 a lock arm which is sized and shaped to receive the second bearing connection, the lock arm receiving the second bearing connection and locking the second bearing connection in place when the link assembly is moved to the first position;   a spring biasing the lock and release mechanism in a locked position; and   a release arm to which a release cable is attached, wherein pulling the release cable pulls the release arm extending the spring and moving the lock and release mechanism from the closed position to an open position.   
     
     
         9 . The side frame assembly of  claim 6 , further comprising a limiter which provides resistance when converting from the first position to the second position and/or from the second position to the first position, the limiter comprising a first end connected to the crank member and a second end connected to the side frame,
 wherein the side frame includes a limiter hole, and the limiter extends from the first end connected to the crank member through the limiter hole and to the second end connected to the side frame.   
     
     
         10 . The side frame assembly of  claim 9 , wherein the limiter is a gas spring. 
     
     
         11 . The side frame assembly of  claim 9 , wherein the side frame includes a raised member which projects away from the side frame, and the second end of the limiter is connected to the raised member. 
     
     
         12 . The side frame assembly of  claim 6 , wherein the lock and release mechanism comprises:
 a lever attached to the crank member, the lever comprising a mating projection, wherein the mating projection mates with a notch formed in the seat link member so as to lock the link assembly in the first position.   
     
     
         13 . The side frame assembly of  claim 12 , wherein:
 a first end of the seat link member is connected to the side frame by way of the first bearing connection, and a second end of the seat link member opposite to the first end includes the groove;   the lever is attached to a first surface of the crank member, and the mating projection projects through a hole formed in the crank member and away from a second surface of the crank member that is opposite to the first surface; and   the lock and release mechanism further comprises a spring biasing the lock and release mechanism in the closed position; and   moving the lever in a predetermined direction moves the mating projection away from the notch so as to allow the link assembly to move from the first position to the second position.   
     
     
         14 . The side frame assembly of  claim 13 , wherein the seat link member includes an angled contact surface angled inward from the notch to a top edge of the seat link member such that the lock and release mechanism is forced open upon application of sufficient force to the contact surface.