Philip Adelbert Friedell.

Speed-Reducing Transmission.

United States Patent 1,730,270.

October 1, 1929.

Engineering idea of a assembling ring gears by pressing a cylindrical gear into ring gear housing cover. US Patent 1,730,270.

Because this is a very old patent some technical terminology in the patent may be different from what is commonly used today. The gear arrangement of this invention can be practical only on high ratio so today it would be more appropriate to call this design a compound planetary rotary gear actuator.

Design concept of a ring gears for a rotary actuator. US Patent 1,730,270.Assembly idea of a ring gears for a rotary compound planetary gear actuator. US Patent 1,730,270.

We have rendered the ring gear 5 and the ring gear housing 12. As we can see, in 1929 the inventor has considered two different design concepts for mechanical rotary gear actuators: "said ring gear being integral with or fixed to said support or housing".

Actuator ring gear can be made as one part or it can be an assembly of two different parts. US Patent 1,730,270.

The inventor realized value of assembling the ring gear out of two different parts.

Adding a gear to the ring gear housing cover. US Patent 1,730,270.

The inventor proposed a solution to fix the cylindrical ring gear inside the ring gear: "The planetary gears 3 mesh with the internal gear 5, which is pressed into the housing cover 12"

Ring gear and the gear housing can be manufactured individually and then assembled. US Patent 1,730,270. Simple cylindrical ring gear fits into a gear housing cover. US Patent 1,730,270.

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