Butter churns all rely on the motion of the cream container to churn the butter. There are no paddles or dashers inside the cream container to agitate the cream. Rather the cream box is swung, rotated or rocked to get the cream moving inside the churn. The motion of the cream hitting the ends of the container is what causes the butter to churn.
This is a Davis Swing Churn, although some very early literature referred to it as a Davis Oscillating Churn. It was patented on May 1, 1877 and September 9, 1879. The 1877 patent was granted to Oliver Davis of Waterbury, Vermont and described a churn of similar shape but it pivoted from below and was rocked back and forth by spiral springs. The 1879 patent was granted to Francis Butler of Bellows Falls, Vermont and assigned to the Vermont Farm Machine Company. Butler was the secretary of the Vermont Farm Machine Company. His patent described a churn almost identical to the one pictured, which was suspended from above in a wood frame.
These churns were made by the Vermont Farm Machine Company of Bellows Falls, Vermont. This is a size 2 or 10 gallon capacity designed to churn 5 gallons of cream. This size butter churn was listed at $8.00 in an 1889 catalog from the company. They were still sold in 1913 and the price had increased by one dollar. This churn has the plain frame. There was a folding frame available for a dollar more. The folding frame made it easier to tilt the churn box to drain out the buttermilk or wash water. There were no paddles inside the churn. As the churn box rocked on the cradle the cream rolled over on itself to make butter. The company said this gentle action did not injure the butter.
https://www.webpal.org/SAFE/aaarecovery/2_food_storage/Eggs/Wood_Butter_Churns_1.html
