Complex sentence: Subsequent improvements were made and another UK patent applied for, this time for deodorising model with integral fan, on 20 May 1970, which was granted on 17 May 1972 (UK patent no.1260402).
Split into simpler sentences: Subsequent improvements were made and another UK patent applied for, this time for a deodorizing model with integral fan on 20 May 1970. It was granted on 17 May 1972 (UK patent no.1260402).