Explosive rivets in US aviation


#1

In 1934 Karl Butter and the aircraft manufacturer Heinkel patented the explosive rivet for aviation use.
Mainly meant for repair of combat damaged aircraft.

There is a 1943 article in a US aviation journal which speaks of this very same development but is featuring it as a US Du Pont development (well, guess wartime allows for such things).
What most people do not know is that all German patents claimed before 1945 were declared something like invalid and got distributed to the business of the Allies. So far so funny.

Question, were these explosive rivets ever used in US aviation and there by the military for repair purposes?

Here a 1945 entry on Du Pont (source internet):


#2

I think my friend has some exploding rivets but not sure who made them.
I will try to get some for a photo if successful.


#3

Alex,
How far back from 1945 were German patents made not valid? Starting with which year? 1920? 1930?
And how did they decide to whom they belonged?


#4

Vlad, all patents before 1945!
No matter who they belonged to before.
The patents and there in particular the classified ones were exploited in any way desired.
This then also reflected in many patents having been claimed again as a new patent in the 1950s or later.

The whole operation (1945-1947) was carried out by the “Field Intelligence Agency, Technical” (FIAT).
Later followed by the much better known “Operation Paperclip”.


#5

Alex, explosive rivets were used by the US in airplane construction, but Du Pont didn’t claim this invention as his own and was well aware of the German patent. In fact, they purchased the manufacturing rights from Heinkel in 1939 and that’s why the German patent is mentioned in US box labels.


#6

Fede, thanks!
In that 1943 article it was only referred to Du Pont, no single word about a German patent - likely the spirit of the time.

The question remains, were these ever fielded with the US Air Force for repair purposes? No matter if before or after 1945.


#7

EOD
The whole discussion about the use of German Patents is a little on the academic side since most
people are not aware of the fact,that after the fall of Berlin in 1945 our friendly red Liberators in the
name of International communist brotherhood and solidarity cleaned out the REICHS PATENT AMT
(office) to the last scrap of paper of course they were all heart figuring the place needed a good
dusting anyways.from the accumulation of patents going back perhaps 200years.
Sherryl


#8

Sherryl, right! The people knowing about this in Germany I can count on one hand!


#9

Very interesting. Thanks for sharing…


#10

My friends father was air plane enthusiast had some that were a flat head aluminum rivet (may have had a light green color). in a fairly short length. This was in the 50’s -60’s. I do not recall who made them but there quite a lot of them. Don’t know what happened to them. When thrown in a fire they made a good bang and became a projectile that you didn’t want to get hit with.


#11

Yes, they were also used for repair purposes by US Army, Air Force and Navy before and after 1945.

It was a great solution to handle inaccessible areas and also to save time. For example, using explosive rivets, the Heinkel He 112 as constructed 1150 hours faster than the He 100.

Regarding the patent discussion, the German patent was purchased by Du Pont because it was considered the best design of its class, but it was not the first explosive rivet patent. It seems that the first one was applied by Frank Allan in 1920, a British citizen.


#12

Fede, thanks!
I have found The Allan patent now. It appears not to be for aviatiuon use and is a more complicated system.
Very valuable info as for the background of the whole!

Is there more info on the US military aviation use of these rivets in relation to repair?
Any manuals available?


#13

Alex, here is an excerpt from a US Navy manual published in 1945.

Aircraft Metal Work - Navy Training Courses - 1945 (p. 116-123).pdf (1.5 MB)


#14

Fede, thanks!
Is the manual designation as given in the pdf file name?
Does it have also a number?


#15

Yes, that’s the manual title, but there is no number. Below you can see the cover.


#16

Fede, thanks! That is important as for the bibliography then.


#17

I spent a lot of time in aircraft maintenance in the USAF starting in the early 1960s, and never encountered, or even heard of explosive rivets as best I can remember. Perhaps this is a deficiency in my education.

Lew


#18

Lew, I understand these rivets were out of the circuit by your time.
Same happened in Germany.

After all these required more safety considerations and then I think the new rivets which came up did not require a “back support” (or how ever that is called in english) anymore and were usable in the same role, just safer.


#19

I spent my career in aviation maintenance too, and started school for that in 1978. Exploding rivets were mentioned briefly, and the lesson was this: They were taken off the list of acceptable fasteners, due to the corrosive effect the propellant had on aluminum. Long before I came along, Cherry rivets and Cherry Max rivets had been invented, which are a type of “pop rivet”, but much more high-tech than the hardware store variety.


#20

Invert, thanks!
So far I read that the last explosive rivets were used in the 1960s (guess the statement was valid for Germany).

Currently I am trying to find out if the USSR ever used these. There I know only that at least by the 1970s non were in use (anymore?).

As I understand the blind rivets used today are the logic consequence of the requirement for such types and avoiding the explosive type.

Also valid for Germany: same rivets just made of steel were used in ship building.
Today obsolete due to all being welded.