Filter patent?

[bakechad]

I recently started using a K&N filter on my 2006 CRV. They are little expensive for what they are. My main motivation is the nut on the bottom. The CRV filter placement makes changing the oil a very painful experience. The K&N reduces that pain by about 50%.

My questions is does K&N have a patent on the nut? I have never seen anyone else with this.

 

[river_rat]

TRD oil filters have the nut, but then again, they are made by the same people as K&N.

 

[Filter guy]

There is no patent on the nut.

It's been around since at least the 1960's. First used on a farm tractor filter, if memory serves.

The reason most filters don't have the nut is the added cost to the filter.

Those cans with the various indentations in the bottom by the dome end..called flutes btw...replaced the nut as a more cost effective way of changing the filter. Hence the need for a cap wrench to remove oil filters.