Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
impinge, infringe (vv.)
To impinge is “to strike, to make an impression, to encroach,” with the preposition on or upon usual in each sense: Her practice times impinged on [upon] mine. Only in the sense “to encroach” is impinge synonymous with the verb infringe (usually also with on or upon; see INFRINGE), which also means “to overlap, intrude upon, or interfere with”: Your proposal infringes on [upon] my patent. Both are Standard in all these senses.
