"Meta-matching" patterns

Question

The title refers to the general problem of writing patterns to match pattern-containing expressions (hence "meta-match").

Here's an example.

In the following rules

0 -> "A"
foo[1] -> bar[2]
{1, 10} -> 11

the left-hand-sides contain no patterns, at least explicitly. I'll refer to such rules as being "pattern-free".

Now, given a list of rules (rules), how can one obtain the sublist consisting only of the pattern-free ones?

This naive solution won't work:

Cases[rules,x_ /; FreeQ[x, (Blank[___] | BlankSequence[___] | BlankNullSequence[___])]]

I can solve this problem at least with the following hack

Cases[(rules /. (Blank | BlankSequence | BlankNullSequence) -> $patt),
      y_ /; FreeQ[y, $patt[___]]]

or

Cases[(rules /. x:(Blank | BlankSequence | BlankNullSequence) -> $patt[x]),
      y_ /; FreeQ[y, $patt[_][___]]
] /. $patt[z_] -> z

...but I figure that Mathematica may provide standard constructs to deal with such situations. If so, I'd like to learn what they are.