PATENT BREAKDOWN: US 2,056,975.
INVENTOR: Charles J. Michal Jr.
WHEN: 1934.
STATUS: Expired.
Charles describes a repeat reset mechanism for the Browning 1911. The patent was filed before a machine gun was defined in the National Firearms Act, which is why he calls it a "machine gun and convertor therefor," as there was no legal definition for a machine gun at the time.
The system is similar to the Super Safety, and about as simple: See Fig. 2. The cam (red) is contacted and rotated counterclockwise by the slide as it moves rearward, this moves the pin (green) forward against the trigger bar (blue, see Fig. 1) moving the trigger forward against the trigger finger. The pin continues to hold the trigger forward until the slide completes its cycle, at which point the cam is free to rotate back allowing the trigger to be pulled again.
The patents own words are: "The trigger 23 fires the piece as before. But, the instant that recoil takes place, the lower edge of the slide 12 engages the cam 28 of the converter 27, thus rotating it counter-clockwise, and forcing the pin 29 forward. This motion of the pin forces the trigger forward against the pressure of the trigger-finger of the man..." And "The pin 29 holds the trigger inoperative against the pressure of the trigger-finger. But, the instant that counter-recoil is completed, the cam 28 is free to move upward again, and consequently the pressure of the trigger-finger immediately again discharges the piece."