Experiments with the Purpose of Expanding the Loading Capacity of Standard Construction Grapples

Abstract

A grapple is a device that includes at least one gripping arrangement. The gripping arrangement is configured to grip and traverse objects so as to reach a desired location on site and to anchor it, therefore allowing the work to be carried out. [1] A method for controlling the fill volume of a grapple, such as a bulk-material crane grapple which includes at least one hoist-and-closure unit, may include adjusting the fill volume of the grapple is during the grapple closure process by adjusting/controlling the grapple hoist height. The grapple hoist speed and/or grapple hoist height may be the controlling parameter for the adjustment of the fill volume of the grapple. [2]Grapples geometric configuration is established by calculating the useful load mass. In the experiments performed in the present paper the load mass was 3000 kg. In exploitation, in cases where relatively low density materials, if compared to standard materials, are being moved/processed, changes to the volume capacity must be done; [3] changes that need to be correlated with the new materials and the exploitation conditions.The tractor attachment is a grapple assembly, and the grapple assembly kit includes a mounting assembly, a plurality of clamping units, and a plurality of support units. [4] A connection system for coupling an claw to a work vehicle includes a receiver assembly that needs to be implement and configured to a connector assembly of an arm of the work vehicle. [5]The solution developed by the authors consists in prolonging and consolidating the active elements of the grapple, by equipping it with additional elements that take and process load tensions, in the present case hard wood logs; and a consolidation and protection system that protects it from wear, that mostly appears when the hook crane repeatedly hits the ground in order to collect the deposited logs.The additional elements for handling and processing logs are made out of low alloyed steel, thus by configuring the tips we assure the good gliding of processed materials on the active/used surfaces. The self-protection system to wear is made out of boron micro-alloyed steel sheets that have hardness values up to 500 HB. Joining the grapple ensemble with specialized elements was performed through welding.