Mine roof supporting system

In a self-advancing mine roof support system having a plurality of roof support units each including a generally horizontal beam supported at opposite ends by a pair of extensible, vertically oriented props so that any one of said units may be adjusted between a roof supporting condition in which the beam thereof is advanced upwardly by the props of that unit into engagement with a mine roof and a retracted condition in which the beam thereof is lowered away from the mine roof, the roof support units being arranged in tandem so that the several horizontal beams of the system are oriented in generally parallel relationship to each other and in transverse relationship to the direction of system advance under a mine roof, a pair of extensible struts extending between and connected to the respective props of each successive two of said units so that any one of said units may be adjusted to said retracted condition and advanced by said struts acting against another of said units adjusted to said roof supporting condition, and pivotal means connecting the upper end of each prop to said beams, the improvement comprising:

• a pair of stabilizing brackets to yieldably retain the props and beam of each roof support unit in perpendicular relationship when each unit is adjusted to said retracted condition and to allow the props and beams of each unit to deflect from a perpendicular relationship when adjusted to said roof supporting condition;
• each of said stabilizing brackets including a rigid angular member having a pair of mutually perpendicular abutment surfaces, one such surface to engage the beam of each unit and the other of such surfaces to engage one of the props of each unit, and tension spring means to bias said abutment surfaces into engagement.