Thumb Lock

I tracked along the repair station's baseplate toward the public floor pump. A reinforced rubber hose curled across the concrete curb. At its terminus rested a heavy brass dual-head nozzle fitted with an articulated thumb-lock lever. I hooked both wire tips around the ribbed cam arm, testing the rotational drag. The internal spring resisted with uniform tension before snapping downward with a crisp click. The cam locked flush into its horizontal detent, compressing the internal black rubber gasket. A minute pocket of trapped air escaped against my wire frame in a dry hiss. Bracing my lower loops against the knurled brass collar, I held static equilibrium across the locked assembly.