Vacuum relief system for tarpaulin covered hopper trailers

Claim 2

Vacuum relief system for hopper trailer having opposing end walls and opposing side walls defining a horizontal upper rim, a bottom including a cargo discharge door, and a tarpaulin covering the trailer hopper and extending around the upper rim in substantially air tight relation thereto, said system comprising: a. an elongated hollow tube; b. means for mounting said tube on the opposing end walls of the hopper at an elevation above the level of the upper rim, said tube extending the entire distance between the end walls and being located below and in supporting relation to the tarpaulin to elevate the same above the level of the upper rim; c. orifice means mounted on the hopper and connected to said tube for establishing communication between the atmosphere and said tube; and, d. nozzle means on said tube for venting atmospheric air from said tube to a location below the tarpaulin, said tube being effective to conduct atmospheric air from said orifice means to a space between the tarpaulin and the subjacent contents of the hopper to equalize the air pressures on both sides of the tarpaulin as the contents of the hopper are withdrawn through the cargo discharge door.

Claim 3

A vacuum relief system as in claim 1 in which said nozzle means and the cargo discharge door are in substantially vertical alignment.

Claim 4

A vacuum relief system as in claim 2 in which said nozzle means is located substantially mid way between the ends of said tube, and in which a pair of said orifice means is connected to the ends of said tube.

Claim 5

Vacuum relief system for tarpaulin covered hopper trailer having cargo-confining side, forward and after end walls providing a horizontal upper rim and floor walls defining a bottom opening selectively covered and uncovered by a hopper discharge door, said system comprising: a. an elongated hollow tube; b. means for mounting said tube on said trailer with at least a portion of said tube overlying the trailer hopper in a position to underlie and support a tarpaulin extending around the upper rim of said hopper in substantially air tight relation and covering the hopper cargo, said tube mounting means including support members mounted on the forward and after end walls and lying in a median vertical longitudinal plane extending through said hopper, said support members including top portions projecting above the level of the upper rim, said tube being mounted on said top portions and extending therebetween to provide a central ridge pole capable of supporting the longitudinally central portion of the tarpaulin at an elevation above the level of the upper rim; c. orifice means mounted on said hopper and connected to said tube for establishing communication between the atmosphere and said tube; and, d. means located on said tube for venting air from said tube to a location below the tarpualin, said tube being capable of conducting atmospheric air from said orifice means to a space between the tarpaulin and the subjacent contents of said hopper to equalize the air pressure on both sides of the tarpaulin as the contents are withdrawn from said hopper.

Claim 6

Vacuum relief system for tarpaulin covered hopper trailer having cargo-confining side, forward and after end walls providing a horizontal upper rim and floor walls defining a bottom opening selectively covered and uncovered by a hopper discharge door, said system comprising: a. an elongated hollow tube; b. means for mounting said tube on said trailer with at least a portion of said tube overlying the trailer hopper in a position to underlie and support a tarpaulin extending around the upper rim of said hopper in substantially air tight relation and covering the hopper cargo, said tube mounting means including support members mounted on the forward and after end walls and lying in a median vertical longitudinal plane extending through said hopper, said support members including top portions projecting above the level of the upper rim, said tube being mounted on said top portions and extending therebetween to provide a central ridge pole capable of supporting the longitudinally central portion of the tarpaulin at an elevation above the level of the upper rim; c. orifice means mounted on said hopper and connected to said tube for establishing communication between the atmosphere and said tube; and, d. means located on said tube for venting air from said tube to a location below the tarpualin, said tube being capable of conducting atmospheric air from said orifice means to a space between the tarpaulin and the subjacent contents of said hopper to equalize the air pressure on both sides of the tarpaulin as the contents are withdrawn from said hopper.

Claim 7

Vacuum relief system as in claim 4 in which said orifice means includes conduits mounted on said support members, said conduits extending upwardly from an air intake port located at an elevation below said upper rim level to an air discharge port located adjacent said top portions of said support members.

Claim 8

Vacuum relief system as in claim 5 in which said venting means includes an opening in said tube intermediate the ends of said tube, and an air nozzle covering said opening and projecting downwardly toward said contents of said hopper.

Claim 9

Vacuum relief system as in claim 6 in which said nozzle is vertically above the hopper door.

Claim 10

Vacuum relief system as in claim 4 including tarpaulin spacing means mounted on the after wall of said trailer below said upper rim of said hopper and interposed between said tarpaulin and said after wall for separating said tarpaulin from said after wall to equalize the air pressure inside said hopper in the vicinity of said upper rim and outside said tarpaulin.

Claim 11

Vacuum relief system as in claim 8 wherein said spacing means includes a bar, and means for mounting said bar on said after wall in spaced relation thereto.

Claim 12

Vacuum relief system as in claim 9 in which there are two of said bars one of said bars being located on said after wall on each lateral side of the after one of said support members.