Frank Clarke – airgun genius. The conundrum of one of his last inventions.

[ggggr]

John--what is the length of the pin compared to standard--in both positions?

[ccdjg]

John--what is the length of the pin compared to standard--in both positions?

Guy, The picture shows the two types of pin more or less to scale. When the retractable pin is pushed right in it pushes the pellet the same distance into the barrel as the standard pin. I can use both types of pin in my pistol and they give exactly the same performance, provided you remember to push the plunger of the retractable pin in fully and release.

There's a clue in there somewhere.

[pjbingham]

A standard probe would obscure the rear bowled section of the pellet where the concentration of air needs to be,a retractable one leaves that area clear?

[rancidtom]

The retractable pin has a larger diameter thus allowing less pellet skirt distortion, but that may be a secondary effect. When pushed to full length it seats the pellet past the transfer port and retracts allowing better air flow than the standard pin which partially restricts air flow from the transfer port.

[cinedux]

dart pusher?

[le frelon]

When the standard pin is screwed in this can cause the pellet to turn and potentially 'ring' the pellet to the bore causing some damage to the soft lead and ruining the seal. Perhaps the spring loaded version is to ensure that the pellet is not rotated in any way. Maybe not such an issue with a smooth bore but could be problematic in a rifled bore?

Or maybe not.

Carl

[Buck25]

If it was an after-market accessory I would think you would find it on other push barrel pistols, not just the Briton. Also note that a similar retractable pin can be found on the 1876 patent for the American made Cross air pistol.

[ggggr]

Guy, The picture shows the two types of pin more or less to scale. When the retractable pin is pushed right in it pushes the pellet the same distance into the barrel as the standard pin. I can use both types of pin in my pistol and they give exactly the same performance, provided you remember to push the plunger of the retractable pin in fully and release.

There's a clue in there somewhere.

So John--if you do not push the retractable pin in and try to fire the pistol, will it actually fire a pellet out or does the pellet obscure the transfer port and there is not enought kinetic energy to shift it? Is the engineering good enough so the seals seal and the barrel moves very slowly (A bit like checking the seal of a tap on a tap loader)???

[ptdunk]

Does it act as a safety catch, in that it won’t fire the pellet unless it’s been pushed past the transfer port?
Load, then when your ready to fire press the insertor in before pulling the trigger?

Matt.

[ccdjg]

Does it act as a safety catch, in that it won’t fire the pellet unless it’s been pushed past the transfer port?
Load, then when your ready to fire press the insertor in before pulling the trigger?

Matt.

Brilliant, Matt, you have nailed it!

Yes, it is probably the most reliable safety device you could have on an air pistol.

Other safety systems on airguns mechanically intercept the trigger or the sear in some way, and if the sear were to slip or shear the gun would still fire the pellet whether the safety was on or not. In this case however the gun is incapable of discharging the pellet (or dart) under any circumstances until the plunger is pushed in.


When I realised that this was what Frank Clarke intended, I couldn’t wait to check it out on my Briton. I cocked the gun, inserted the pellet with the pin and screwed it home. Sure enough, the gun would not fire the pellet. You could cock and fire it until you were blue in the face and the pellet would not budge. Not surprising really when you think about it! However, one push on the retractable knob and the gun fired the pellet with no problem.

As a safety it is great, as you can activate the gun at the last possible moment while it is on target, just with the thumb of your shooting hand. It also means that you could carry the pistol around ready cocked and with a pellet in the breech with perfect safety - very useful when hunting large game I should imagine.

Frank Clarke obviously had a thing about unusual safety devices as he invented a very simple safety system for his later Titan pistols. On these the safety is released just before firing by squeezing the grip.

I wonder why he never patented his retractable pin idea? It would have been universally applicable to any push barrel pistol, or any pistol loaded by a breech pin, such as the Anson Star. All it would have needed was minor modification of the plunger length and the thread. To put a traditional safety catch on an existing push barrel pistol would have required major reconstruction work and new tooling (as Harrington took on with his later Gats).

Does anyone have any thoughts as to why Frank Clarke never capitalised on his invention, given the great number of push barrel pistols around at the time that could have benefited from it?

[P.S. I liked Rich's suggestion that the pin could have been used to allow two pellets to be fired in succession. Unfortunately it didn't work when I tried it out. It seems that as the two pellets are pushed up tightly aganst each other in the breech, the air can't get between them to push the first pellet out.]

[cringe]

Brilliant, Matt, you have nailed it!

Yes, it is probably the most reliable safety device you could have on an air pistol.

Other safety systems on airguns mechanically intercept the trigger or the sear in some way, and if the sear were to slip or shear the gun would still fire the pellet whether the safety was on or not. In this case however the gun is incapable of discharging the pellet (or dart) under any circumstances until the plunger is pushed in.


When I realised that this was what Frank Clarke intended, I couldn’t wait to check it out on my Briton. I cocked the gun, inserted the pellet with the pin and screwed it home. Sure enough, the gun would not fire the pellet. You could cock and fire it until you were blue in the face and the pellet would not budge. Not surprising really when you think about it! However, one push on the retractable knob and the gun fired the pellet with no problem.

As a safety it is great, as you can activate the gun at the last possible moment while it is on target, just with the thumb of your shooting hand. It also means that you could carry the pistol around ready cocked and with a pellet in the breech with perfect safety - very useful when hunting large game I should imagine.

Frank Clarke obviously had a thing about unusual safety devices as he invented a very simple safety system for his later Titan pistols. On these the safety is released just before firing by squeezing the grip.

I wonder why he never patented his retractable pin idea? It would have been universally applicable to any push barrel pistol, or any pistol loaded by a breech pin, such as the Anson Star. All it would have needed was minor modification of the plunger length and the thread. To put a traditional safety catch on an existing push barrel pistol would have required major reconstruction work and new tooling (as Harrington took on with his later Gats).

Does anyone have any thoughts as to why Frank Clarke never capitalised on his invention, given the great number of push barrel pistols around at the time that could have benefited from it?

[P.S. I liked Rich's suggestion that the pin could have been used to allow two pellets to be fired in succession. Unfortunately it didn't work when I tried it out. It seems that as the two pellets are pushed up tightly aganst each other in the breech, the air can't get between them to push the first pellet out.]

Pre load?

I was thinking safety catch, but there is no indication weather it is on or off! and one would know if the gun was ready to fire or loaded as the barrel would be extended [safe] or inserted [live]. I think it was used as a method of "pre loading" your pistol as they can be fiddly, unscrewing, small pellets , oop's have just dropped the screw in the grass & it's going dark ! etc.
I would not want to carry a loaded Gat in my pocket, just in case some thing faild & I ended up with that extended barrel in my nut's

regards al

try this, what I meant with pre loading was you might have the facility to have two pellets in the breech? [1] load 1st pellet & push forward, so it would be ready to fire [2]. load 2nd pellet but do not push forward [like it would be reserved] [3] after first shot re-cock & push forward, you would have the ability to do two consecutive shots without all the fiddly reloading?
does that make sense?
regards al

[ccdjg]

Pre load?

I would not want to carry a loaded Gat in my pocket, just in case some thing faild & I ended up with that extended barrel in my nut's

regards al

Thanks for putting that image in my mind. Made my eyes water.

[DT Fletcher]

Does anyone have any thoughts as to why Frank Clarke never capitalised on his invention, given the great number of push barrel pistols around at the time that could have benefited from it?

You're making the assumption that this was the creation of Clarke. Just as likely would be that this was the invention of somebody else who manufactured them and sold them completely independent of Clarke. As I have already mentioned, this "safety" breech plug is of a completely different manufacturing than the original. Which strongly suggests that it was not produced in the same factory as the original. I think you have what we would today call an "aftermarket accessory."

[ccdjg]

You're making the assumption that this was the creation of Clarke. Just as likely would be that this was the invention of somebody else who manufactured them and sold them completely independent of Clarke. As I have already mentioned, this "safety" breech plug is of a completely different manufacturing than the original. Which strongly suggests that it was not produced in the same factory as the original. I think you have what we would today call an "aftermarket accessory."

With the advantage of being able to make a close comparison of the two types of pin I am pretty confident that both came from Frank Clarke’s workshop (same thread, same knurling and same dimensions of the knob). At the the time of FC’s Briton (1925-30) , the only other push-barrel pistols on the market were the Lincoln Jeffries Scout and the German Dolla pistols, all of which had different breech screw threads, so the likelihood that the retractable pin was an aftermarket accessory manufactured and sold independently of Clarke is extremely low. Also we have to remember that (at best) only five examples are known, all specific to the Briton.

If it was an after-market accessory I would think you would find it on other push barrel pistols, not just the Briton. Also note that a similar retractable pin can be found on the 1876 patent for the American made Cross air pistol.

It is an interesting point about the Cross patent, and I have long wondered if Clarke might have been inspired by this. However, on balance I think that it is extremely unlikely. The Cross patent was confined to the USA only, was granted some 50 years before the Briton appeared, and was never actually commercialised so in those pre-internet days it is improbable that Clarke would have ever been aware of the Cross patent. In any event, in the Cross patent the plunger is just described as a loading aid and makes no suggestion that it might also serve as a safety device.

[VALE BOY]

[QUOTE=ccdjg;7675096]Brilliant, Matt, you have nailed it!

“Yes, it is probably the most reliable safety device you could have on an air pistol.

Other safety systems on airguns mechanically intercept the trigger or the sear in some way, and if the sear were to slip or shear the gun would still fire the pellet whether the safety was on or not. In this case however the gun is incapable of discharging the pellet (or dart) under any circumstances until the plunger is pushed in.”

I suppose it could be said that the most effective safety device on an air rifle would be on underlever air rifles such as the Webley Mk3, BSA Airsporter and Diana Modell 50 and other similar guns with a swivelling loading tap lever.

When left in the loading position irrespective if there’s a pellet in the breech, it effectively prevents the passage of air to continue through to the muzzle. I quite often use this as a ‘safety catch’ whilst using my Mk3s and Airsporters.... and it is of course ‘resettable’ whenever you twist the lever back to the ‘open’ position.