3 men in a corner

[crabber]

Late in a match with Team A leading by a goal, 3 players from team A surround the ball in and around it's own corner kick arc. Each player is within playing distance of the ball preventing B, by space, from getting to the ball. Is this legal? I have seen 1 player " take it to the corner", but never 3. Note even if B fouls one of the three players, a free kick is taken (with B 10 yds from the ball) and it starts all over again.