ELECTRIC HAMMER Russian patent published in 2010 - IPC E02D7/02 

FIELD: building.

SUBSTANCE: electric hammer contains a body with a three-phase primary winding on its internal surface. The body comprises a floating a head anchor with a short-circuited conductive winding on its external surface. It also accommodates head anchor position sensors and a frequency-controlled supply and control system, a hatchway with shock-absorbers. The electric hammer is made of N primary bodies and startors respectively with bearings on their ends. There bodies in upper and lower parts have guides of the head anchor travel. Said bodies and guides are placed in the second body formed along the full length of the first bodies and guides with air gaps, The guides in upper and lower parts have the apertures connected with said gaps. The upper cover of the upper guide is provided with a spring shock-absorber, and in the upper and lower parts of the second body of the electric hammer there are sucking and discharge fans respectively. The frequency-controlled supply and control system can be connected to a storage battery.

EFFECT: ensured high reliability and improving efficiency.