Patent ID: 8042207

Claim:
A holding mechanism for foldable side rails, comprising: an upper horizontal rail member; a lower horizontal rail member; at least two stanchion members pivotally rotatably connected between the upper horizontal rail member and the lower horizontal rail member, forming a parallel link mechanism, the holding mechanism keeping the stanchion members erect, and is disposed at an end of the upper horizontal rail member; and a mechanism support member connected to at least one of the stanchion members provided at said end, and comprising: a spring; a stopper pin set capable of advancing and receding; a stopper pin set disposed to receive the stopper pin on one end and contact the spring on the other; wherein the at least one of the stanchion members has a fitting hole for allowing the stopper pin set to be fitted in it when the stanchion members are kept erect; a mechanically driven trigger site; a release lever engaged with the 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 provided between the release lever and the mechanically driven trigger site; a release prevention mechanism preventing the movement of the release lever in the release allowing direction, the play mechanism configured so that the stopper pin can be automatically fitted into the fitting hole when the upper and lower horizontal rail members are raised; and a cover enclosing at least one of the spring, stopper pin set, cylinder, and release prevention mechanism, having a pocket formed partially in the place where the release lever is pressed for release action, wherein the spring is disposed between the cover and the cylinder, and wherein the stopper pin set is biased in the advancing direction by the spring.