<http://webisa.webdatacommons.org/171959387>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<freepatentsonline.com> .
<http://webisa.webdatacommons.org/prov/474081659>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/171959387> .
<http://webisa.webdatacommons.org/171959387>	<http://www.w3.org/ns/prov#value>	"While various materials can be employed in the system of the present invention, most advantageously metal is used because of its strength, durability and relative light weight." .
<http://webisa.webdatacommons.org/171959387>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .