English to Spanish Law/Patents Law: Contract(s)

It is within the Terms and Conditions of Purchase of a Purchase Order. The paragraph goes like this: "SECURITY: If Buyer makes any advance or progress payment to Seller under the Purchase Order, upon Buyer's request, Seller agrees to execute a Security Agreement and Financing Statement (both in form satisfactory to Buyer) granting a Security interest to Buyer effective in all states of fabrication or manufacture in the proceeds, raw materials and goods which are purchased, manufactured, or otherwise obtained pursuant to the Purchase Order."

My translation goes: «...presentará un contrato de garantía y un estado financiero (satisfactorios para el comprador) que le garanticen al comprador un gravamen sobre la recaudación, las materias primas y los materiales que se compran...». What do you say? ¿Se puede poner un gravamen sobre la recaudación o ganacia de algo?