Side roll up tarpaulin system for a flatbed trailer

1. A side lifting/closing tarpaulin system for a flatbed trailer, the trailer having an elongated platform having front and rear ends, sides, a front bulkhead and a rear bulkhead, the front bulkhead and rear bulkhead extending upwardly from the platform at respective front and rear ends, and a plurality of tarpaulin supporting beams extending laterally across the platform, and longitudinally along the platform, the system comprising:

a pivoting front arm and a corresponding pivoting rear arm, each of the front and rear arms supported by the corresponding front and rear bulkhead, the front and rear arms pivotable, in corresponding fashion, with respect to a side of the platform, between an upper, open orientation and a lower, closed orientation, each front and rear arm pivotable in a plane parallel to that of the corresponding front and rear bulkhead about a pivot mounted to said front or rear bulkhead, a intermediate portion of the rear arm being bent from the plane parallel to the rear bulkhead;

a roller bar extending between and supported by an outer end of each of said front and rear arms;

the tarpaulin supported in rolled fashion on the roller bar when the arms are in upper, open orientation, opening the corresponding side of a trailer and being supported by the support beams, and being rolled off the bar and enclosing the corresponding side when the arms are in lower, closed position;

each front and rear arm provided with an elongated slot along a longitudinal axis of the arm, said front and rear arms mounted relative to said respective front and rear bulkheads such that said pivot sits within said slot in a manner that permits longitudinal movement of the arm relative to said pivot;

mechanical drive means to rotate said roller to roll or unroll said tarpaulin thus causing movement of the arms between said open and closed positions; and

a locking mechanism to selectively lock or unlock the drive means during rotation of the roller.

2. The system of claim 1 wherein said drive means comprises a manual control associated with said front arm.

3. The system of claim 2 wherein said manual control comprises a crank shaft operationally connected to a chain in order to impart rotation to said roller.

4. The system of claim 1 further comprising a biasing means to urge the unrolled tarpaulin into a locked position relative to a bottom of said platform while said front and rear arms are in said lower closed position.

5. The system of claim 4 wherein said biasing means comprises a spring.

6. The system of claim 1 wherein said drive means is a chain drive associated with said front arm.

7. The system of claim 1 further comprising a second tarpaulin, a second pair of front and rear arms and second drive means to cover the opposite facing side of the trailer.

8. The system of claim 1 wherein said front and rear arms are rigid and of fixed length.

9. The system of claim 1 wherein at least one of the plurality of tarpaulin supporting beams comprises a telescoping top rail.