Patent ID: 7474522

Claim:
A height adjustment mechanism, said mechanism comprising: a first sliding component that comprises a first set of mechanical structures for engaging a second set of mechanical structures; a first mechanical sub-component coupled to said first sliding component and integrated with a second mechanical sub-component that forms a peripheral portion of said first mechanical sub-component and comprises said second set of mechanical structures; and a second sliding component coupled to said first sliding component for sliding in a direction opposite to the sliding direction of said first sliding component, wherein said first mechanical sub-component and said second mechanical sub-component are located between said first sliding mechanism and said second sliding mechanism and said first set of mechanical structures and said second set of mechanical structures are configured to mesh wherein a movement of said first sliding component causes either an expansion or a retraction of said first mechanical sub-component through rotation of the second mechanical subcomponent; wherein the first mechanical sub-component comprises a spring and the second mechanical sub-component comprises a gear.