| 49 / | HD | MOVABLE OR REMOVABLE CLOSURES |
| 263 | DF | TREADLE OR IMPACT INITIATED OPERATOR {8} |
| 269 | ![]() | .~ Spaced open and close initiators on opposite sides of closure {2} |
| 270 | DF | .~.~> Plural interconnected paired initiators |
| 271 | DF | .~.~> Releases latch from either side |