Patent ID: 7717375

Claim:
A rotation control device for a support arm of a lamp, comprising; a support arm having a first end; a second end and a tube joint ( 24 ) between the first end and the second end; the tube joint ( 24 ) having a protrusion ( 241 ) which is formed with a threaded hole ( 242 ); a rotating arm having a first end and a second end; a lamp head assembled to the second end of the rotating arm; a cambered track fixed to a predetermined position of the support arm; and a cambered slot being formed in the cambered track; a stop sheet; and wherein the stop sheet is a threaded rotating button which is screwed to the threaded hole ( 242 ) of the protrusion ( 241 ) of the rotating arm ( 20 ); and the protrusion of the rotation arm passes through the cambered slot of the cambered track so that the stop sheet ( 60 ) is movable along the cambered slot; and wherein the stop sheet ( 60 ) has a handle ( 61 ), a press plate ( 62 ) connected to the handle ( 61 ), and a stud portion ( 63 ) connected to the press plate ( 62 ), the press plate is formed with a pressing surface; when the stud portion ( 63 ) passes through the cambered slot ( 51 ) of the cambered track ( 50 ) and is screwed to the threaded hole ( 242 ) of the protrusion ( 241 ) of the tube joint ( 24 ), they form a cambered guide structure; when the pressing surface of the press plate ( 62 ) presses upon the cambered track ( 5 ), the rotating arm ( 20 ) is guided along the cambered track ( 50 ) to be at a predetermined angle.