US 3,968,974 A · Brakeable hand truck

Abstract

A hand truck having a flat, rigid, annular disc coaxially fixed to each of a pair of outboard wheels between the hand truck frame and the wheel. A respective caliper having two parallel fingers which hold respective brake pads is mounted on the hand truck frame adjacent the periphery of each disc so that the two fingers are disposed on either side of the disc for forcibly pinching the disc between the brake pads. The calipers and associated mounting hardware are specially structured so as to minimize the space between the inside of the wheel and the outside of the frame. To ensure even wear of the brake pads the wheels are mounted on bearings which permit axial sliding of the wheels on their axle so that the discs float between the two caliper brake pads. The calipers are actuated in response to hydraulic pressure produced by a master cylinder which in turn is operated through a bell crank linkage by a lever placed directly below a hand truck handle so that the lever may be pulled upwardly by a squeezing motion. The wheel and disc structure is designed so as to permit the use of a single common axle for both wheels, thereby minimizing the weight and cost of the hand truck brake system.

Claims7

Dependent claims

A brakeable hand truck comprising, in combination:

a. a generally upright, load-supporting frame having a lifting blade projecting forwardly adjacent the bottom of said frame;
b. a pair of laterally spaced wheels rotatable independently from one another mounted to the rear of said frame adjacent the bottom thereof on a single common axle attached to said frame, for movably supporting said hand truck;
c. a disc coaxially fixed directly to each of said wheels so as to rotate in unison therewith;
d. a pair of calipers fixedly attached to said frame respectively on each side thereof, each caliper having two spaced finger members disposed respectively on each side of a respective disc for forcibly pinching said disc therebetween;
e. bearings mounting said wheels on said axle, said bearings permitting said wheels to move laterally on said axle with respect to said frame;
and
f. actuator means connected to said calipers for causing said finger members to pinch said respective disc.

4 more elements

A brakeable fulcrumed hand truck for manually moving freight comprising, in combination:

a generally upright elongate frame;
a rearwardly projecting grip handle attached to said frame near the top thereof for manually manipulating said hand truck;
a forwardly projecting lifting blade attached to said frame adjacent the bottom thereof for supporting said material to be moved by said hand truck;
a pair of laterally-spaced, rearwardly projecting side support members attached to said frame adjacent the bottom thereof;
a single axle mounted on said side support members such that said axle is disposed across said frame transversely at the bottom and to the rear thereof and projects laterally outwardly from each said support member for supporting a pair of wheels;
a pair of laterally spaced wheels rotatable independently from one another each mounted on said axle outwardly from a respective one of said side support members for movably supporting said hand truck, said frame being fulcrumed on said wheels about the axis of said axle;
a pair of discs, each connected to one of said pair of wheels so as to rotate in unison therewith, said discs being oriented in a vertical plane perpendicular to said axle and located between their respective wheels and the closest of said side support members so as to provide a pair of braking surfaces located outwardly of each said side support member and oriented vertically so as to prevent the accumulation of moisture and dust on said braking surfaces;
a pair of hydraulically-actuated calipers mounted respectively on each side of said frame, each said caliper having two spaced finger members disposed respectively on each side of a respective disc for forcibly pinching said disc therebetween by engaging said braking surfaces;
a hydraulic master cylinder mounted on said frame for pressurizing said calipers;
parallel hydraulic conduit means connecting said master cylinder to each of said calipers such that equal hydraulic pressure is transmitted from said master cylinder to each of said calipers for actuation thereof;
and a hand-operated brake handle disposed adjacent said grip handle and connected by a mechanical linkage to said master cylinder for operating said master cylinder to produce hydraulic pressure therein and thereby actuate said calipers to forcibly engage said vertical braking surfaces, the combination of said calipers, master cylinder and mechanical linkage providing a mechanical advantage causing the force applied by said calipers to be greater than the force applied to said hand-operated brake handle.

8 more elements

Dependencies are inferred from the claim text.

Brakeable hand truck

Life of this patent

Brakeable hand truck

Life of this patent

Abstract

Claims7