260 the outer angled edges 213 215 cause pistons 262 264 to compress their respective springs 269 and 265 respectively until the pistons 262 264 expand and snap into the grooved indentations 217 219 of the blade 210 to remove the blade 210 latching handles 263 267 are manually moved in the direction of arrows d4 and d5 respectively allowing blade 210 to be separated from slot 260 of mounting arm 240 fig4 a is an exploded view of a fourth preferred embodiment 300 of the detachable blade 310 and mounting arm 340 fig4 b is a side view of the mounting arm 340 of fig4 a along arrow e1 fig4 c is a front view of the mounting arm 340 of fig4 b along arrow e2 fig4 d is a top view of the mounting arm 340 of fig4 b 4c without a top plate cover 350 fig4 e is a side view of the latching piston 364 and latching handle 367 for use with the embodiment 300 of fig4 a 4d referring to fig4 a 4e mounting arm 340 includes curved narrow connecting arm portion 346 and curved ceiling fan motor mount 348 similar to those described in the previous embodiments arm mount 340 further includes two parallel plates 350 and 370 which are connected to one another through a central housing 382 and 384 by screw fasteners 351 the width of central housing 382 384 is smaller that the width of the plates 350 370 so that.