Dump trailer and system for a semi-trailer truck

A method of controlling unloading of a dump trailer comprising:

• providing a tub, defining an exterior portion, comprising:
• a web;
• a left wall adjoining the web;
• a right wall adjoining the web and symmetrical to the left wall;
• a closed end adjoining the web, left wall, and right wall;
• an open end:
• oppositely disposed from the closed end;
• and, adjoining the web, the left wall, and the right wall;
• a hinge axis formed through the left wall and the right wall;
• a left hinge formed on the exterior portion of the left wall and coaxial with the hinge axis;
• a right hinge formed on the exterior portion of the right wall and coaxial with the hinge axis;
• a distal draft arm axis adjacent to the web and on the exterior portion of the web;
• a center hinge formed on the web and coaxial with the distal draft arm axis;
• and
• a center plane symmetrically disposed between the left wall and the right wall;
• providing a coupling plate, configured to engage the dump trailer to a semi-trailer truck, comprising:
• a hydraulic cylinder axis formed on the coupling plate;
• a left hydraulic cylinder hinge:
• formed on the coupling plate;
• and coaxial with the hydraulic cylinder axis;
• a right hydraulic cylinder hinge:
• formed on the coupling plate;
• and coaxial with the hydraulic cylinder axis;
• a proximal draft arm axis formed on the coupling plate;
• and
• a draft arm hinge formed on the coupling plate;
• and coaxial with the proximal draft arm axis and the distal draft arm axis;
• providing a left hydraulic cylinder, defining a left cylinder length, comprising:
• a proximal end attached to the left hydraulic cylinder hinge;
• and
• a distal end oppositely disposed from the proximal end and attached to the left hinge on the tub;
• wherein addition of a first amount of fluid changes the left cylinder length;
• providing a right hydraulic cylinder, defining a right cylinder length, comprising:
• a proximal end attached to the right hydraulic cylinder hinge;
• and
• a distal end oppositely disposed from the proximal end and attached to the right hinge on the tub;
• wherein addition of a second amount of fluid changes the right cylinder length;
• providing a rear assembly attached to the tub adjoining the web and adjacent to the open end, the rear assembly comprising:
• a first pair of wheels;
• a rear pivot about which the tub rotates;
• and
• a second pair of wheels parallel to the first pair of wheels;
• a spring assembly comprising:
• at least one leaf spring comprising first end and a second end;
• a first axle attachment on the first end;
• and
• a second axle attachment on the second end;
• a hinge symmetrically attached between the first end and the second end of the at least one leaf spring;
• wherein the first pair of wheels are attached to the first axle attachment with a first axle;
• and
• wherein the second pair of wheel are attached to the second axle attachment with a second axle;
• wherein the rear pivot about which the tub rotates is coaxial with the hinge of the rear assembly;
• operating the dump trailer between a transporting condition and a dumping condition,
• wherein the transporting condition, the tub is in a stationary position;
• and
• in the dumping condition, increasing the left cylinder length and the right cylinder length for extending the left hydraulic cylinder and the right hydraulic cylinder respectively;
• and
• increasing in both the left cylinder length and the right cylinder length:
• rotating the tub about the rear pivot;
• compressing the at least one leaf spring in the spring assembly thereby controlling the unloading of the dump trailer.

A dump trailer for a semi-trailer truck comprising:

• a chassis plane formed on the semi-trailer truck, wherein the chassis plane is defined by at least two axles of the semi-trailer truck that are coplanar to the chassis plane;
• a tub, comprising:
• a web;
• a left side adjoining the web;
• a right side adjoining the web;
• and
• a center plane formed on the tub, wherein the center plane is symmetrically located between the left side and the right side;
• a draft arm symmetrically disposed between the left side and the right side of the tub, the draft arm comprising:
• a proximal end;
• and
• a distal end oppositely disposed from the proximal end;
• a coupling plate to engage the dump trailer to the semi-trailer truck, wherein:
• the proximal end of the draft arm is attached to the coupling plate;
• a left hydraulic cylinder defining a left cylinder length, the left hydraulic cylinder comprising:
• a proximal end rotationally attached to the coupling plate;
• and
• a distal end oppositely disposed from the proximal end and rotationally attached to the tub;
• a right hydraulic cylinder defining a right cylinder length, the right hydraulic cylinder comprising:
• a proximal end rotationally attached to the coupling plate;
• and
• a distal end oppositely disposed from the proximal end and rotationally attached to the tub;
• a rear assembly pivotally attached to the tub at the web, the rear assembly comprising:
• a first pair of wheels;
• and
• a rear pivot around which the tub rotates;
• a perpendicular condition wherein:
• the center plane of the tub is perpendicular to the chassis plane;
• and
• the left cylinder length and the right cylinder length are equal;
• and
• a canted condition wherein:
• the center plane is non-perpendicular to the chassis plane;
• and
• the right cylinder length and the right cylinder length are different.