What is this dagger?

[Bladefinder]

Please help,

I have found a dagger that was in our attic and i don't know where its from.

The balde is 3 sided coming to a sharp point, wooden handle grip. The guard is possibly brass with 6 pyramidal outcroppings. On the hilt is stamped into it :
U.S. L. F. & C. 1917. The scabbbard is Brass and leather and stamped into the leather is Jewell 1918. Any help is greatly appreciated.

Thanks

 

[Merek]

"I have found a dagger that was in our attic and i don't know where its from." It was from you attic... you said so.

Sounds like a WW1 trench knife.
Do a Google 'Image' search. You'll probably recognize it.

 

[Bladefinder]

Thanks. Your right i did say that didn't I

 

[Bladefinder]

Thanks Merek you are right. big help!

 

[DaveH]

Sounds like a bayonet to me, rather than a dagger.

 

[Merek]

No bayonets with a knuckle-duster guard sporting pyramidal points. It was basically a brass knuckle with a spike dagger.

 

[Bladefinder]

Merek is right i found the picture on google its a 1917 WWI trench knife

 

[Bastid]

Here is the 1915 version the guard is bent to form the duster. The blade is triangular.