Assertion: marker | /r/HasProperty | developed at bell labs
Facets:
value: in the 1930s
type: TEMPORAL
value: successfully
type: MANNER
Source sentences:
text: After unfruitful German efforts in the 1920s, they were successfully developed at Bell Labs in the 1930s to support the then new generation of crossbar switches which were replacing the Step-by-Step switches and Panel switches of the first generation of automatic switching.