Pipeline padding system

DETAILED DESCRIPTION The present invention provides apparatus for laying a trench bed layer consisting of fine grained material derived from unclassified fill material.
The system includes a main frame that is pivotally supported by a hitch means carried by the tool arms of a front end loader.
The hitch means include a support bar that extends as a cantilevered beam in the direction of travel of the front end loader whereby the main frame is securable to the support bar so as to extend transverse to the travel direction of the front end loader.
Hydraulic cylinders normally used for manipulating the tool arms of the front end loader vary the attitude or angle of attack of the main frame in accordance with ground slope.
The hitch means also carries means for pivoting the main frame about a pin connection joining the main frame and the support bar.
The apparatus further includes a storage hopper carried by the main frame into which unclassified backfill material is loaded.
The storage hopper mouth is preferably provided with a grizzly to preclude large rock and oversize masses of clay fill from entering the hopper.
An upwardly inclined, longitudinally extending (in relation to the main frame) conveyor transports the fill material from the bottom of the hopper to a higher elevation whereupon the fill is discharged from the conveyor and preferably passes through a comminuting station before falling onto a downwardly inclined, laterally extending (in relation to the main frame) vibrating screen.
The speed of the conveyor may be varied to adjust the flow of backfill onto the vibrating screen to allow for varying backfill consistencies, moisture content, padding and bedding material size specifications and the like.
Additionally, the attitude of the apparatus may be adjusted so as to compensate for changes in right-of-way elevation, i.
e.
, uphill, downhill and side hill conditions.
Still further, the screen is preferably double-decked with the upper screen element being of a coarser mesh than the lower screen element