In order to create draw, the teeth of the escape wheel are undercut and the locking faces of the pallets are inclined; so that the pressure of the teeth on the locking faces produces a drawing-in motion of the pallets toward the escape wheel. The ultimate action of this motion will be to bring the pallet fork against the banking pins and hold it there. The safety roller is then perfectly free and the pallet in position for the next vibration.
A diamond charged lap facilitates the operation when it is necessary to grind the pallet slots. A copper lap mounted on a taper is used. After the diamond powder is rolled into the lap, the outer edge of the back of the lap is turned thin enough to allow the lap to enter the pallet slot without binding. The back edge of the lap is turned very thin, after the diamond powder is applied; in order to prevent the thin edge from bending while being charged.
In order to increase the draw the pallets are tilted or inclined toward the impulse and locking surfaces of the escape wheel. If it is necessary to decrease the draw the pallets should be inclined away from the locking and impulse surfaces of the escape wheel. It is not necessary to incline the pallets a great amount in order to secure the desired effect. It should be noted in the drawing that the pallet slot is ground at an angle. Sometimes just the one pallet can be moved or inclined; and the desired effect will be secured without appreciably altering the drop.