About: http://webisa.webdatacommons.org/131961360

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	The rounded protrusion may be formed by various methods as are know in the art including melting the distal ends of the helical coil and forming wires by the use of a welder as disclosed in U.S. Pat. No. 4,811,743 to Stevens.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es