You can pretty much carry any blade in Oregon if you're not a felon.
The only real blade law for non felons is the following: ORS 166.240 Carrying of concealed weapons. (1) Except as provided in subsection (2) of this section, any person who carries concealed upon the person any knife having a blade that projects or swings into position by force of a spring or by centrifugal force, any dirk, dagger, ice pick, slungshot, metal knuckles, or any similar instrument by the use of which injury could be inflicted upon the person or property of any other person, commits a Class B misdemeanor.
So the real effect of that is that if you carry a switchblade, you should have an exposed clip to avoid violating the law. (and if you have a sword, try not to conceal it on your person). But the Oregon legislature made it very clear that Oregonians have a right to defend themselves - so if you were to get busted for having a concealed sword or switchblade and actually fought the charge in court, there's a good chance the concealed weapon law would be found unconstitutional. Yay for Oregon!
Note Section 27 of the Oregon constitution: Right to bear arms; military subordinate to civil power. The people shall have the right to bear arms for the defence (sic) of themselves, and the State, but the Military shall be kept in strict subordination to the civil power[.]
This is why it's so easy to get a concealed carry permit in Oregon.
Here's a good link for the Oregon Constitution and statutes:
http://www.law.cornell.edu/states/oregon.html