A device for striking a bell comprises a hammer head having a head portion composed of hard material and another head portion composed of soft material to obtain both hard and soft sounding bell rings. The hammer head is connected to a rockable striking hammer lever which is driven with a rocking motion by a rotating eccentric cam to cause the hammer head to strike the bell. The center of rocking motion of the striking hammer lever can be shifted both manually and automatically to selectively vary the hardness and softness of the bell ring.