1878. Cooke and Hibbert (4068).—The bedplate constructed in the form of a circular segment with a much larger face than usual, and capable of adjustment, the beater roll itself being fixed in the bearings.
1880. Forbes (692).—A long oval shaped beating engine divided into three channels instead of two. In the two outer channels are placed beater rolls and drum washers. The stuff discharged over the backfalls from the two beating engines flows down the central channel and is circulated by a special paddle constructed in such a manner as to deliver the pulp in two equal streams into the outer channels to each of the beater rolls.
1880. Umpherston (1150).—An engine constructed with a passage below the backfall so that the stuff circulates in a trough underneath the beater roll, the object being to ensure more effective treatment and to save floor space.
1883. Aitchison (5381).—A beating engine of usual form, but with the beater roll made conical in shape with the larger circumference outwards, and the bedplate placed on an incline parallel with the knives on the beater roll.
1884. Mayfield (2028).—The backfall of the beating engine is of entirely different construction to the ordinary machine, for the purpose of improving the circulation.
1884. Hoyt (11177).—An engine resembling the Umpherston, but with a larger roll, the diameter of which is equal to the full depth of the engine, the backfall being in a line with the axis of the beater roll.
1885. Jordan (7156).—Additions to the Jordan engine for admitting water and steam to the engine as required.
1885. Korschilgen (9433).—The beater roll made of stone or of metal with a stone casing furnished with ribs or knives placed close together.
1886. Hibbert (4237).—A beating engine fitted with an ordinary beater roll, and having in addition a heavy disc rotating vertically, the disc being fitted with knives on one surface which rotate in contact with knives fixed on a stationary disc.