Holding mechanism for foldable side rails

Abstract

The conventional holding mechanism for foldable side rails have such problems that the release lever can be accidentally pressed for release action and that if a double lock is employed for preventing it, automatic holding action cannot be performed. This invention proposes a holding mechanism for foldable side rails, characterized in that the holding mechanism 4 is provided at an end of an upper horizontal rail member 1 u and comprises a mechanism support member 5 connected with the stanchion member provided at said end; the mechanism support member 5 has a stopper pin set 12 capable of advancing and receding; the stopper pin set 12 is biased in the advancing direction by a spring 13 ; the stanchion member has a fitting hole 10 allowing the stopper pin set 12 to be fitted in it when the stanchion member is kept erect; the mechanism support member further has a release lever 6 engaged with a mechanically driven trigger site 15 provided in connection with the stopper pin set for making the stopper pin set recede against the force of the spring; a play mechanism is provided between the release lever and the mechanically driven trigger site; and the mechanism support member further has a release prevention mechanism for preventing the movement of the release lever in the release allowing direction.

1 . A holding mechanism for foldable side rails that have plural stanchion members pivotally rotatably connected between an upper horizontal rail member and a lower horizontal rail member, to form a parallel link mechanism, said holding mechanism being provided for keeping the stanchion members erect, characterized in that the holding mechanism is provided at an end of the upper horizontal rail member and comprises a mechanism support member connected with the stanchion member provided at said end; the mechanism support member has a stopper pin set capable of advancing and receding; the stopper pin set is biased in the advancing direction by a spring; the stanchion member provided at the end has a fitting hole for allowing the stopper pin set to be fitted in it when the stanchion member is kept erect; the mechanism support member further has a release lever engaged with a mechanically driven trigger site provided in connection with the stopper pin set, for making the stopper pin set recede against the force of the spring; a play mechanism is provided between the release lever and the mechanically driven trigger site; and the mechanism support member further has a release prevention mechanism for preventing the movement of the release lever in the release allowing direction. 
   
   
       2 . A holding mechanism for foldable side rails, according to  claim 1 , wherein the play mechanism consists of a slot formed in the mechanically driven trigger site and a pin installed in the release lever and engaged with the slot. 
   
   
       3 . A holding mechanism for foldable side rails, according to  claim 1 , wherein the play mechanism consists of a recess formed in the mechanically driven trigger site and opening in the horizontal direction and a pin installed in the release lever and engaged with the recess. 
   
   
       4 . A holding mechanism for foldable side rails, according to  claim 1 , wherein as the release prevention mechanism, a lock member with a contact portion to be kept in contact with the upper face of the release lever is movably provided in the upper portion of the mechanism support member, while a recess designed to avoid contact with the contact portion is formed in the upper face of the release lever, in the case where the release lever is moved upward for release action. 
   
   
       5 . A holding mechanism for foldable side rails, according to  claim 4 , wherein the recess is formed as the lower horizontal one of two horizontal levels. 
   
   
       6 . A holding mechanism for foldable side rails, according to  claim 4 , wherein the lock member is biased by a spring in the direction in which the release prevention mechanism acts. 
   
   
       7 . A holding mechanism for foldable side rails, according to  claim 5 , wherein the lock member is biased by a spring in the direction in which the release prevention mechanism acts. 
   
   
       8 . A holding mechanism for foldable side rails, according to  claim 1 , wherein the mechanism support member can function as a cover for covering mechanism components and has a pocket formed partially in the place where the release lever is pressed for release action.