Portable and frameless folding cart capable of being folded without increasing height

A portable and frameless folding cart capable of being folded without increasing the height, comprising:

• four vertical bars (11) used for supporting and divided into two front vertical bars and two rear vertical bars;
• bottom sleeves (123) mounted at bottom ends of the vertical bars (11);
• a first cross bar (15) and a second cross bar (126) which are mounted between the bottom sleeves (123);
• first retaining rings mounted at the bottom ends of the front vertical bars and second retaining rings mounted at the bottom ends of the rear vertical bars;
• first upright bars (12) rotatably arranged on the first retaining rings and second upright bars (13) rotatably arranged on the second retaining rings;
• hinge sleeves (14) mounted on the second upright bars (13) and hinged to the first upright bars (12);
• first rotating rings mounted on the front vertical bars and second rotating rings mounted on the rear vertical bars;
• a first diagonal bar (110) mounted on one of the first rotating rings and a second diagonal bar (111) mounted on one of the second rotating rings;
• a wheel mechanism (3) used for driving the cart to move;
• a pulling mechanism (4) to be held by a worker;
• and
• a folding assembly used for supporting a bottom of the cart when the cart is in an unfolded state, wherein the folding assembly comprises:
• lower ring sleeves (118) fixedly mounted on the first diagonal bar (110) and the second diagonal bar (111), wherein upper rotating shafts (119) are rotatably arranged on the lower ring sleeves (118), a link (120) is mounted between the two upper rotating shafts (119), two transition sleeves (121) are arranged on the link (120), and second openings are formed in upper ends of the transition sleeves (121).

A portable and frameless folding cart capable of being folded without increasing the height, comprising:

• four vertical bars (11) used for supporting and divided into two front vertical bars and two rear vertical bars;
• bottom sleeves (123) mounted at bottom ends of the vertical bars (11);
• a first cross bar (15) and a second cross bar (126) which are mounted between the bottom sleeves (123);
• first retaining rings mounted at the bottom ends of the front vertical bars and second retaining rings mounted at the bottom ends of the rear vertical bars;
• first upright bars (12) rotatably arranged on the first retaining rings and second upright bars (13) rotatably arranged on the second retaining rings;
• hinge sleeves (14) mounted on the second upright bars (13) and hinged to the first upright bars (12);
• first rotating rings mounted on the front vertical bars and second rotating rings mounted on the rear vertical bars;
• a first diagonal bar (110) mounted on one of the first rotating rings and a second diagonal bar (111) mounted on one of the second rotating rings;
• a wheel mechanism (3) used for driving the cart to move;
• a pulling mechanism (4) to be held by a worker;
• and
• a folding assembly used for supporting a bottom of the cart when the cart is in an unfolded state;
• wherein, an extension mechanism (2) is arranged at an upper end of each said vertical bar (11) and comprises an extension block (22) disposed around the upper end of the vertical bar (11), an oval groove is formed in the vertical bar (11) and penetrates through the vertical bar (11), a transition bar (25) is slidably arranged in the oval groove, and an extension bar (21) is mounted in the transition bar (25);
• a spring (26) is mounted between the transition bar (25) and a bottom of the oval groove, and a limit step is arranged at a bottom end of an inside of the extension block (22) and divides the inside of the extension block (22) into a first section located below and a second section located above, wherein a size of the first section matches a size of the transition bar (25), and a size of the second section is less than the size of the transition bar (25);
• a bump (252) is arranged at a bottom of the transition bar (25), and a slideway matched with the bump (252) is arranged on the first section of the extension block (22).