Adjustable rotation chair

A rotatable and adjustable chair, comprising:

• a base for stabilizing said chair on a floor;
• a frame rotatable on a shaft engaged in a bearing on said base;
• said frame comprising:
• a lower bar having an axis parallel to the plane of said floor and a connecting plate at a center of said lower bar rotatably engaged to said shaft;
• a first end of each of two v-shaped arms integrally engaged to each end of said lower bar;
• said v-shaped arms rising above said lower bar at an acute angle to said plane of said floor;
• a first reinforcing bar parallel to said lower bar fixedly engaged at its ends respectively to each of said two v-shaped arms;
• a first tubular member fixedly engaged to said connecting plate and a center of said first reinforcing bar;
• and
• a second tubular member, disposed in said first tubular member having a pair of bearings disposed therein at both ends;
• a first end of a slidable bar slidably engaged within said pair of bearings;
• said slidable bar having a pair of transverse pins limiting slidable movement of said first end of said slidable bar within said second tubular member;
• control means threadingly engaged through said first tubular member and said second tubular member for fixing said slidable bar relative to said second tubular member;
• a first edge of each of a back and a seat of said chair being rotatably engaged to each other;
• a second end of said slidable bar being rotatably engaged to a bottom of said seat;
• a second end of each of said two v-shaped arms rotatably engaged to side edges of said back;
• wherein, when said control means is disengaged from said slidable bar, a user can adjust the inclination of said back and said seat to a desirable angle and then fix said back and said seat at said angle by fixing said control means to said slidable bar.