an attachment point for rod end pin 234 that move within linear slot 214 linear actuator 240 which may preferably be a hydraulic cylinder includes a rod end 241 and barrel end 242 rod end 241 accepts rod end pin 234 which slides in linear slot 214 barrel end 242 accepts pin 243 which slides in locking slot 216 and arm slot 223 it is understood that actuator 240 may also be reversed where the rod end and barrel end are opposite as shown and described bias member 250 includes spring barrel 151 containing spring 152 that tends to bias arm 220 toward a closed position spring 252 exerts a force on the protruding end 224 of arm 220 this force acts against body 210 and tends to pivot arm 220 about pivot 226 toward the closed position the force exerted by spring 252 can be overpowered by the force applied by actuator 240 a flexible flat belt 260 runs over motor sprocket 233 idler rollers 213 and 225 and around pipe 270 belt 260 is preferably constructed from a flexible strong material such as kevlar u00ae or some other durable high strength woven composite material in the preferred embodiments belt.