The KwK 36 main gun had a feature found in most or all German guns of the time; a device to automatically open the breech block after the gun was fired.
The breech ring had a large lever on its right-hand side for manually opening the breech, but normally the automatic system was used instead. It would cause the breech block to drop while the gun was moving forward from its recoil position.
The system comprised a lever on the left-hand side of the breech ring, and this semi-automatic bracket attached to the gun shield (this is the British name for it). The example in this photo belongs to the Tank Museum's Tiger "131" and the photo was taken before restoration of that vehicle. It bears 50 years' worth of dust. [1]
These are the basic dimensions of the device's mounting plate.
Returning to Tiger "131", on the other side of the gun shield we can see the device's fixing bolts, its torsion spring housing, and the ring-pull on the latch for removing the cam bracket.
Each of these devices had two locating pins to ensure precise positioning. But, the pins are found in different locations in all surviving Tigers. I have not drawn them on my sketch.
[1] Survey of Tiger 250122, at Bovington museum, by David Byrden