193,549. Copeland Chatterson Co., Ltd., and Mann, A. Dec. 6, 1921. Locking-followers.- In a post file wherein the clamping bar sliding on the posts contains camoperated, sliding, locking plates adapted to grip or release the posts, the cam member f is provided with a projection g adapted to engage an abutment i on the clamping member so as to limit its turning movement. The posts c are attached to a solid clamping bar a and pass through the slidable bar b containing spring members j, j, the free ends of which normally grip the posts. Slidable plates e, e bent downwards and bifurcated at their outer ends, are adapted, when forced outwards by the engagement of the cam member f with their flanged inner ends, to lift the members j, j and release the posts.; The projection g on the cam member is semi-circular and moves in a slot g, of circular form having a right-angled abutment i formed therein which limits the movement of the cam member.