The first production helicopter was the S47/R4 which was delivered to the US Army in May 1942.
From the Sikorsky archives:
The XR-4 helicopters featured a 36 foot 3 bladed fully articulated main rotor and a 3 bladed tail rotor powered by a Warner Scarab 175 hp R-500-1 seven cylinder air cooled radial engine. The XR-4 had a 2 place side-by-side cockpit with dual flight controls. As a weight saving measure, only one main rotor pitch control lever (collective) was installed in the center of the cockpit One Experimental XR-4 helicopters was built The first flight was on January 14, 1942.
The Sycamore HR14 also had a central collective which took some getting used to. I used to demonstrate left cyclic/right collective with the AP out approaches on the 332L to show young co-pilots what it was like. However, civil Sycamores had dual collectives though not as big as the HR14s.