I know Federsitz for a motorcycle, for example, as "sprung seat," so I'd probably try "sprung thrust/pressure piece."

with three spring plungers .....

spring plunger is a correct translation
I have also seen "spring loaded .....", which I personally do not like.

Clearly a modern codpiece, maybe motorised.

spring loaded thrust piece oder spring loaded pressure piece

CM :-)) I had a similar association :-)

I'll ask for a picture tomorrow morning, and will then compare all your suggestions - thanks a million!

Another example, in this case of an American supplier.

In den Maschinen, die der amerikanische Maschinenbauer, für den ich arbeite, herstellt sind es federnde Stempel und Matrizen, die im amerikanischen Original als spring-loaded punches/dies bezeichnet werden.

Alternativ wird auch sliding punches/dies verwendet.

Morning, All!

Just heard from my customer - s/he searched the Web and found "spring plungers," as John had mentioned in #2.