operation of the latch from inside the building is achieved of course by depressing the touch bar which moves the finger 72 rightwardly fig1 as described this movement causes rightward movement also of the plate 134 which moves the rounded element 116c rightward to retract the latch when the touch bar 12 is subsequently released from the manual pressure it pops out to the position shown in fig1 due to the force of the spring 58 fig4 and the leftward urging on the drive plate 134 fig4 resulting from the action of spring 122 and spring 128 both of which urge element 116c leftward the latter causes the plate 134 to return to its home position against the cam 140 as already described the dogging cam 60 fig7 may be rotated by an allen wrench through opening 66 engaging the allen wrench shape hole 68 on the axis of rotation of cam 60 alternatively a lock cylinder may be mounted on the cover plate 16 in an opening enlarged from opening 66 the 34 cam 34 or drive element of such a cylinder will as the key is rotated one way or the other alternately engage the opposite side surfaces of the wing of dogging cam 60 which carries the surface 64 such a cylinder will have its drive lever mated into recess 69 in the cam 60 activating the cam 60 causes the projection 50 to be held up holding the touch bar in its inner position with finger 72 retracting the latch in such a state the door may be freely opened from either side being biased toward the closed.