Device for changing frame angle of foldable article

A device for changing a frame angle of a foldable article, the device combining leg frames using a connecting and assembling member and an elastic string and thus makes up a leg or a support frame of the foldable article, the device comprising:

• the connecting and assembling member with which a first end of the elastic string is combined in a manner to be fixed or to pass through and which has a plurality of combination grooves each of which has a shape that corresponds to a cross-sectional shape of a leg frame wherein the leg frame combined with a second end of the elastic string is selectively combined with the connecting and assembling member in an angle-changing manner at a varying installation angle;
• the elastic string having the first end that is fixed to or that passes through the connecting and assembling member and the second end that is combined with the leg frame wherein the leg frame is elastically operable;
• and
• the leg frame that is combined with the second end of the elastic string and that is elastically insertable into or separable from the connecting and assembling member,
• wherein an opening portion that is a lengthwise-extending hole is formed in the connecting and assembling member, and the connecting and assembling member includes a combination block portion that forms a plurality of combination grooves by partitioning the opening portion,
• the combination block portion is configured with first and second block pieces that are inserted into the opening portion and then are symmetrically combined with the connecting and assembling member,
• wherein an arc-shaped concave portion is formed in both sides of each of the first and second block pieces, a semi-circle concave groove is formed in the middle thereof, and an insertion protrusion is formed on an external surface thereof, and
• insertion grooves into which the insertion protrusions, respectively, are inserted are formed in an internal circumferential surface of the connecting and assembly member and thus, the first and second block pieces are removably combined into the insertion groves, respectively.