Abstract: A locking apparatus includes an actuating hub rotatably mounted on a base, a handle connected with the actuating hub, a control plate provided adjacent to the actuating hub and formed with a plurality of teeth, two locking tumblers, and a series of button engagement disc clutch plates and coding disc clutch plates mounted on the locking tumblers, whereby pressing a selected group of buttons rotates their respective button engagement disc clutch plates and coding disc clutch plates such that cut-out apertures formed on the coding disc clutch plates align with the teeth of the control plate, thereby allowing movement of the control plate and rotation of the actuating hub when the grip handle is rotated. The apparatus also includes a code change button and a reset button.