A coupling assembly for securing an end of a tube to a connecting shaft of a device is provided. The coupling assembly comprises an inner sleeve having a first end, an opposite second end, a first end section at the first end and a second end section at the second end, and an outer sleeve having a first end, an opposite second end and a second end section at the second end. The second end section of the outer sleeve is sized and shaped to receive at least the first end section of the inner sleeve therein. An interior surface of the second end section of the outer sleeve is provided with a protrusion or a recess to engage a corresponding recess or protrusion on an exterior surface of the inner sleeve. The second end section of the inner sleeve is flexible.
