Some sentences that I have seen contain the pattern "verb + 了 + verb". An example of this is:
"他們碰了碰杯子。" [1]
Since in all examples that I have seen the verb before and after 了 is the same, I believe that this pattern is a combination of verb reduplication and 了1 (comes after verbs and expresses completion).
A very literal translation of the above sentence would therefore be:
"They have briefly hit the glasses."
So far, I have been unable to verify or falsify the above hypothesis. Am I on the right track or does the "verb + 了 + verb" pattern express something else?
[1] https://www.chineseboost.com/grammar/peng-pengjian-pengshang/