About: http://webisa.webdatacommons.org/185301351

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	It is to be noted that in the embodiments of FIGS. 3A and 3B and 5A, 5B and 5C, the springs 508 may be omitted and the guards 302, 502 may be advanced and retracted manually through mechanical, hydraulic, pneumatic or other means.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com