All About Pocket Knives

I recently saw a European ad for a knife that described the opening mechanism as "pump open system." A picture of the knife shows no nail nick or no buttons on the side for blade release or safety switch. It does show a back spring extension protruding on the butt. I'm thinking that this is the release mechanism. Any help would be appreciated.

Welcome to AAPK. Sorry but without more information I have no idea about the knife you describe. Perhaps it has an internal spring triggered by pressing the backspring protrusion you describe. Some pictures, or a link to the ad might help someone determine what it is. Who is the manufacturer?

Ken

Chris Pizzini wrote:I recently saw a European ad for a knife that described the opening mechanism as "pump open system." A picture of the knife shows no nail nick or no buttons on the side for blade release or safety switch. It does show a back spring extension protruding on the butt. I'm thinking that this is the release mechanism. Any help would be appreciated.

In what country did the advert originate? It’s most likely an issue with the English translation. I suspect from your description that the knife is simply a “normal” lockback. I have a rather extensive collection of French knives and French knife books and literature, and have seen the same misleading description in French knife literature that has been (poorly) translated to English. For example, one of my books refers to a Buck 110 and a Gerber Gator as “pump open knives”. Go figure…

Chris Pizzini wrote:I recently saw a European ad for a knife that described the opening mechanism as "pump open system." A picture of the knife shows no nail nick or no buttons on the side for blade release or safety switch. It does show a back spring extension protruding on the butt. I'm thinking that this is the release mechanism. Any help would be appreciated.

From the description I think they call that a “flipper”. Here is a picture of my SOG Bluto. It does have a thumb stud, but it also has that extension of the blade, which you can see in the picture, it’s on the bottom. When the knife is closed that sticks out of the top of the knife and you can just push it with your finger while rotating your hand and the blade flips open.
Don’t know if that’s the same as a pump open system but it sounds like the same thing.
SSk

Sharpnshinyknives wrote:

Chris Pizzini wrote:I recently saw a European ad for a knife that described the opening mechanism as "pump open system." A picture of the knife shows no nail nick or no buttons on the side for blade release or safety switch. It does show a back spring extension protruding on the butt. I'm thinking that this is the release mechanism. Any help would be appreciated.

From the description I think they call that a “flipper”. Here is a picture of my SOG Bluto. It does have a thumb stud, but it also has that extension of the blade, which you can see in the picture, it’s on the bottom. When the knife is closed that sticks out of the top of the knife and you can just push it with your finger while rotating your hand and the blade flips open.
Don’t know if that’s the same as a pump open system but it sounds like the same thing.
SSk

The OP stated that the backspring extension protruded from the butt of the knife. Flipper tabs are attached to the blade of the knife near the blade’s pivot. As I previously stated in this thread, traditional backspring-release lockbacks are often referred to as “pump opening” or “pump-activated” in English translations of French knife books and catalogs. To illustrate my point, I’ve attached a few (poor quality) photographs of pages from the coffee table book Collectible Pocket Knives, written by Dominique Pascal. The book was published and printed in France in 2001.

Chris Pizzini wrote:I recently saw a European ad for a knife that described the opening mechanism as "pump open system." A picture of the knife shows no nail nick or no buttons on the side for blade release or safety switch. It does show a back spring extension protruding on the butt. I'm thinking that this is the release mechanism. Any help would be appreciated.

Chris, I just noticed your PM—sorry, I didn’t realise that you were asking about an automatic knife. I believe (I’m not certain) that the knife in your photographs is spring-loaded and both opens and closes by depressing the backspring/lockbar release at the rear of the knife. If this is the case, the knife is relatively rare. I managed to find some photos of similar knives online—they’re towards the bottom of the page in the included link.

http://www.autoknife.info/French_5.html

Greenman wrote:

Chris Pizzini wrote:I recently saw a European ad for a knife that described the opening mechanism as "pump open system." A picture of the knife shows no nail nick or no buttons on the side for blade release or safety switch. It does show a back spring extension protruding on the butt. I'm thinking that this is the release mechanism. Any help would be appreciated.

I just noticed your PM—sorry, I didn’t realise that you were asking about an automatic knife. I believe (I’m not certain) that the knife in your photographs is spring-loaded and both opens and closes by depressing the backspring/lockbar release at the rear of the knife. If this is the case, the knife is relatively rare. I managed to find some photos of similar knives online—they’re towards the bottom of the page in the included link.

http://www.autoknife.info/French_5.html

Greenman, I hadn’t heard of a pump knife before or even seen one. My mistake.
I had never seen a bolster lock either until about 8 years ago, when I found one in a colllection I purchased. I had to study the knife and finally concluded that the bolster had to move for me to unlock it to let it fold closed. About broke my thumb trying to figure that one out. Nearly sliced it on the blade too. What a dumb idea. I wonder whether those pump locks are also difficult to operate?
SSk

Sharpnshinyknives wrote:

Greenman wrote:

Chris Pizzini wrote:I recently saw a European ad for a knife that described the opening mechanism as "pump open system." A picture of the knife shows no nail nick or no buttons on the side for blade release or safety switch. It does show a back spring extension protruding on the butt. I'm thinking that this is the release mechanism. Any help would be appreciated.

I just noticed your PM—sorry, I didn’t realise that you were asking about an automatic knife. I believe (I’m not certain) that the knife in your photographs is spring-loaded and both opens and closes by depressing the backspring/lockbar release at the rear of the knife. If this is the case, the knife is relatively rare. I managed to find some photos of similar knives online—they’re towards the bottom of the page in the included link.

http://www.autoknife.info/French_5.html

Greenman, I hadn’t heard of a pump knife before or even seen one. My mistake.
I had never seen a bolster lock either until about 8 years ago, when I found one in a colllection I purchased. I had to study the knife and finally concluded that the bolster had to move for me to unlock it to let it fold closed. About broke my thumb trying to figure that one out. Nearly sliced it on the blade too. What a dumb idea. I wonder whether those pump locks are also difficult to operate?
SSk

SSk, I was never a big fan of bolster releases, either.
I’ve only ever handled one of these backspring-activated automatics. Perhaps it was my own lack of coordination, but as I recall, it took both of my hands to open the blade. A two-handed auto-opening knife would seem rather absurd…