Braking device for portable cart

A braking device of a portable cart, comprising:

• a loading plate 2, which is formed to load goods thereon;
• a pair of front wheels 3 and a pair of rear wheels 10, which are mounted at a lower side of the loading plate 2 to be rotatable;
• a handle 7, which is supported at an upper side of the loading plate 2, is foldable in a forward direction, and is provided with clamping units 200 so as to maintain a state of being raised upwardly;
• buffer units 8, which are installed at both front corners of the loading plate 2 and perform buffering and steering functions when the loading board 2 collides with an obstacle;
• and
• a braking unit 100, which brakes and controls the rear wheels 10,
• wherein
• the braking unit 100 includes:
• a plurality of engaging grooves 12, which are formed along a rim of a circular recesses 11 formed on an inner side of each of the rear wheels 10 that face each other;
• a brake bar 20, which is disposed between the rear wheels 10 and controls the rotation of the rear wheels 10 by being selectively received in the engaging grooves 12 with both ends thereof disposed in the recesses 11 facing each other;
• an actuating link 30, which is penetratingly supported by the brake bar 20 and is connected to a hinge portion 32, installed below the loading plate 2, so as to rotate the brake bar 20;
• a connecting link 40, which is connected to the actuating link 30 by an interlocking bar 42, fixed at the rear of the actuating link 30, so as to be rotated;
• a connecting spring 50, which is connected to the brake bar 20 and the interlocking bar 42 so as to elastically maintain a distance between the brake bar 20 and the interlocking bar 42, a push switch 60, which is fixed at an upper side of the connecting link 40 and is supported through the top of the loading plate 2 so as to be vertically lifted up or down on the loading plate 2, and a foot brake pedal 70, which is fixed at an upper side of the push switch 60 and has a top surface exposed at the top of the loading plate 2,
• during the driving of the rear wheels 10, the top surface of the foot brake pedal 70 is disposed either in line with the top surface of the loading plate 2 or within a protective guide 98, which is formed not to protrude from the loading plate 2, and
• during the braking of the rear wheels 10, the foot brake pedal 70 is projected beyond the upper side of the loading plate 2 or the protective guide 98 and thus visually informs a user that the rear wheels 10 are being braked.