自動 じどう膨張 ぼうちょう しきではありませんでした
jidōbōchō shikidewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 自動膨張式

1. Was not self-inflating.; Was not automatic inflating.

Past/Perfective
Negative
Polite
Formal Register