Huh?
"A lawn sweeper, also known as a leaf sweeper, is a garden tool for the mechanical removal of debris, such as fallen leaves, pine needles, twigs, grass clippings or litter, from a lawn or paved area. Lawn sweepers operate via a rotating brush mechanism that sweeps up the debris and deposits it in a collection hopper for disposal."
You can push them by muscle power or pull behind a lawn tractor.
Google or whatever for pictures.