Abstract: In a reciprocating harpoon-type conveyor operated by a hydraulic circuit, a control system for the conveyor which includes pressure sensitive switches in the hydraulic circuit operated in response to increases in hydraulic pressure indicative of stoppage of the conveyor. The control system is responsive to operation of pressure switches to reverse the conveyor and to sense whether the conveyor is jammed, whether the jam is cleared, and if not, terminates operation of the conveyor.

Abstract: A closed loop conveyor for viscid material is provided with a plurality of spaced, planar conveying flights within a material conveying conduit. The flights are mounted on an endless transporting chain and are moved from one or more charge stations where material is loaded into the conduit to one or more gravity discharge stations where the material falls out of the conveyor. At the discharge station the planar conveying flights are scraped clean by a rotatable assembly. The assembly preferably comprises a circular plate mounted for rotation in a generally vertical plane adjacent to the conveying path and about a substantially horizontal axis. A number of scraper blades are mounted on the circular plate substantially uniformly, peripherally spaced from one another and extend away from one side of the plate in a generally horizontal direction toward a conveying path defined by movement of the flights.

Abstract: A reciprocating harpoon-type conveyor for transporting swarf-like material along a conveyor trough is provided with non-jamming barbs each of which comprises a multi-faced member secured to the inside surface of the upwardly extending walls of the conveyor trough. Each barb has an inwardly-slanted feed surface which increasingly projects into the conveyor trough in the downstream direction and a rearwardly slanted retaining surface which extends upwardly in the upstream direction and away from the bottom of the trough. An upstream edge portion and a downstream edge portion of each barb substantially merge with an upstanding wall of the conveyor trough. The feed surface is adapted for slidable passing of swarf-like material thereover as the material is moved forwardly in the conveyor. The slanted retaining surface is adapted for engaging and retaining a portion of the swarf-like material in place as the harpoon is retracted from a forward position to a rearward position during return stroke.

Abstract: Apparatus for crushing swarf and like materials having a circuit for controlling the operation thereof which provides for operating the crusher for selected time durations in order to insure processing of a load of material, and including means for temporarily interrupting the operating cycle in response to any of a plurality of abnormal conditions and for shutting down the crusher if the abnormal conditions are not corrected within a predetermined time interval.