Actually, 47 of them over his 24-year career, about two per season. But it was 27 years ago today, May 16, 1984, that Carlton Fisk not only hit a triple... but a single, double and home run, becoming (at the time) only the ninth catcher in baseball history to hit for the cycle.
Since then, four others have joined him. Of the 13 backstops who have cycled, three of them had the triple in that game as the only three-bagger of their career: the Pirates' Bill Salkeld in 1945, Chad Moeller of the Brewers in 2004 and Bengie Molina, then with the Rangers, in 2010.
Fisk had a very strange year in 1984. He hit 21 home runs, but drove in only 43 runs, which at the time was the fewest RBI in a season for anyone with 20 or more dingers. (Since "underpassed" by Kevin Maas, 41 in 1990 with 21 HR and Chris Hoiles, 40 in 1992 with 20 HR.)