Supporter retained by bottom of furniture

A supporter retained by a bottom of a furniture, comprising:

• a polygonal base plate having a plurality of through holes;
• four feet being formed to four bottom corners of the base plate for standing on a floor;
• two pushers threaded into the base plate;
• at least one supporting bolt for elevating the supporter so that the pushers can clutch or release a bottom of an object;
• a long slider sliding arranged to the bottom surface of the base plate;
• an end of the slider having a through hole;
• a sleeve having a round base on a lower portion and a hollow cylinder on an upper portion;
• the base having a flat cut on a side for preventing interference;
• the base being fixed to the slider above the through hole;
• a bolt set being arranged to the through hole through the sleeve for securing the slider;
• wherein the supporter serves to be fixed below a couch or a bed for connecting an extension supporting rack;
• the base plate of the supporter is placed into a gap below a couch, and the pusher is raised to approach a bottom of the couch with claws pointing to a proper position of the bottom of the couch;
• by turning the at least one supporting bolt towards the floor, the supporter is raised with the claws tightly clutching the couch;
• the slider is pulled out to a predetermined position;
• and the bolt set is lowered to the floor so that the supporter is fixed to the location;
• the extension supporting rack is slid into the sleeve for operation.