The History of Kent/FRD Hydraulic Breakers

The hydraulic hammer known today as FRD, is made by a company in Japan known as Furukawa Rock Drill.  In their most likely attempt to “Americanize” the name, they were first sold in this country as the Kent Hydraulic Breaker. Those first series of hoe rams were green in color, and known as the “HB” series; standing for “hydraulic breaker”. Shortly thereafter, they introduced the “KHB” series; standing for “Kent Hydraulic Breakers”.

Most of these early hydraulic hammers had a side plated design. This design sandwiches the power cell, or main body, between two large plates that run the length of the breaker and are held together with large double ended cross bolts. The hammer top cap, or mounting bracket bolts to the top of each side plate, enables your skid steer, mini excavator, backhoe or full-sized excavator to pin on to the entire hydraulic hammer assembly. Most all of, the HB and KHB series of hydraulic breaker were of the today common nitrogen fired, or nitrogen assist design, which uses nitrogen in the back head of the hammer that acted as a bowstring. The bowstring was pulled back by hydraulic power. 

The early Kent hydraulic hammers also featured on board accumulators, which would help to absorb spikes coming from the carrier’s auxiliary hydraulic system and redirect some of that energy. We are not sure who invented this design for hoe rams or rockbreakers, but it is used in our Gorilla Hydraulic Breakers, Atlas Copco, Okada, NPK, BTI, Chicago Pneumatic (CP) and more.