Pennsylvania Knife Laws?

They are illegal, per Pennsylvania C.S.A. 18.908:

As used in this section "offensive

weapon" means... any... dagger, knife, razor or cutting

instrument, the blade of which is exposed in an automatic

way by switch, push-button, spring mechanism, or

otherwise...

That is a switchblade, and it is illegal to make, repair, sell (or otherwise deal in), use, or possess such a knife. There is one exception:

Exception.--

It is a defense under this section for the defendant to

prove by a preponderance of evidence that he possessed of

dealt with the weapon solely as a curio or in a dramatic

performance, or that he possessed it briefly in

consequence of having found it or taken it from an

aggressor, or under circumstances similarly negativing any

intent or likelihood that the would be used unlawfully.

What that means is, AFTER your arrested and on trial, you can raise the above as a defense.

Illegal.