ROOFING OF POWERED SUPPORT UNIT Russian patent published in 1994 - IPC

FIELD: roof support in stopes. SUBSTANCE: roofing has canopy with upper sheet and rear wall. Canopy guides accommodate extensible wedge-like spalling device and ram moving spalling device and connected with it and with rear wall through ear. Spalling device ram is installed for additional displacement of its ear. Spring is arranged between rear wall and ear. Upper planes of ear are inclined at acute angle to ram axis and contacts transverse beam provided with toothed catches. Rigidly connected to beam are one ends of levers, whose other ends are articulated with upper sheet for turning levers in vertical plane and contacting toothed catches with roof through ports made in upper sheet. EFFECT: higher efficiency. 2 dwg