US Patent 8465071 Multiple-unit indexing clamp with mating vertically-grooved stacking units

Disclosed is multiple-unit indexing, mechanical scissor clamp for handling one or more modular segmental retaining wall units, also called “SRW blocks” having opposite ends each provided with a vertical groove. This clamp allows the user to move SRW blocks from a shipping pallet to a wall. The clamp and blocks are lifted using traditional construction machinery such as a backhoe, crane, bobcat, etc. The significant innovation of this clamp/block system is the ability to lift and place more than one large segmental retaining wall block with each installation cycle, substantially increasing installation efficiency.