Patent ID: 7537093

Claim:
A brake device for a pushcart, the pushcart having a cart frame and a first wheel disposed rotatably on the cart frame, said brake device comprising a main braking mechanism that includes: a pin-engaging member adapted to be connected fixedly to the first wheel and having a plurality of angularly equidistant grooves; a base adapted to be disposed fixedly on the cart frame; a rotary lever disposed pivotally on said base and rotatable on said base between first and second positions, said rotary lever being biased to said first position and being operable to rotate from said first position to said second position, said rotary lever including a hollow shaft body that is journalled on said base and that has an annular inner surface; a cam member disposed rotatably within said shaft body of said rotary lever, said cam member being formed with a cam surface that has a convex portion and a concave portion, said convex portion being disposed nearer to said pin-engaging member than said concave portion; and a braking pin disposed movably on said base and biased to contact said cam surface of said cam member, said braking pin being movable on said base between a braking position, where said braking pin contacts said convex portion of said cam surface of said cam member and where said braking pin engages one of said grooves in said pin-engaging member, and a release position, where said braking pin contacts said concave portion of said cam surface of said cam member and where said braking pin is removed from said grooves in said pin-engaging member, rotation of said rotary lever from said first position to said second position resulting in movement of said braking pin from one of said convex portion and said concave portion of said cam surface of said cam member onto the other one of said convex portion and said concave portion of said cam surface of said cam member.