Adjusting structure for an armrest of a chair

An adjusting structure for an armrest of a chair comprising:

• a support member, an armrest, a side cover, a press member, a guiding member, a housing, and an engaging unit;
• wherein
• the support member includes a first bore and two arcuate grooves, all of which are disposed on a vertical section thereof, the arcuate groove proximate to a lower side of the vertical section of the support member includes a limiting recess mounted on a lower side thereof, and the support member also includes a plurality of slots fixed on a horizontal section thereof, such that the support member allows to be engaged to a seat by using a number of screw elements;
• the armrest includes a second bore, a third bore, a fourth bore, all of which are arranged on a lower side thereof, and a notch formed on a bottom end thereof;
• the side cover includes an upper orifice and a lower orifice in response to the third bore and the second bore respectively, and includes a receiving chamber formed on a bottom end of an inner side thereof to insert the press member, a fitting zone disposed on the inner side thereof to receive a lower section of the armrest, and a cutout disposed on a bottom end thereof;
• the press member includes a through orifice mounted on a vertical section thereof to insert a second projection of the guiding member therein, and an arcuate defining tab formed on a bottom end thereof;
• the guiding member includes a first projection extending from an upper side thereof and the second projection extending from a middle portion thereof;
• the housing is covered to an outer side of the side cover;
• the engaging unit includes a second resilient element and a steel ball to be received in an opening of the side cover and the fourth bore of the armrest so that the steel ball is pushed by the second resilient element to abut against the support member.