Displaceable mine roof support assemblies

A mine roof support frame comprising a roof-engaging structure, a floor-engaging structure, hydraulic props disposed between the roof and floor-engaged structures, a shifting mechanism with a guide beam and an hydraulic ram for displacing the frame;

• wherein the guide beam is connectible to a shiftable abutment, the floor-engaging structure is composed of a pair of side-by-side elongate sills spaced apart to produce a space therebetween with the shifting mechanism being located in the space between the floor sills, a housing is provided for the ram of the shifting mechanism and at least partly surrounds said ram, the guide beam is disposed beneath the ram housing and is positioned to rest on the floor of a mine working during use;
• independent guide means acting between the guide beam and the ram housing serves to guide the ram housing and the guide beam for relative movement predominantly longitudinally of the floor sills while permitting vertical and tilting adjustments between the guide beam and the ram housing, and respective connection means connects the ram to the ram housing for vertical displacement therewith and connects the ram to the guide beam whereby to maintain the guide beam in contact with the floor of the mine working;
• wherein the guide means comprises a guide rail partly received in a guide element with clearance therebetween, the guide rail and the guide element being positioned at the central region of the space between the floor sills;
• and wherein the guide rail has a T-shaped cross section and the guide element engages around a crosspiece of the guide rail in the manner of a claw.

A mine roof support frame comprising a roof-engaging structure, a floor-engaging structure, hydraulic props disposed between the roof and floor-engaged structures, a shifting mechanism with a guide beam and an hydraulic ram for displacing the frame;

• wherein the guide beam is connectible to a shiftable abutment, the floor-engaging structure is composed of a pair of side-by-side elongate sills spaced apart to produce a space therebetween with the shifting mechanism being located in the space between the floor sills, a housing is provided for the ram of the shifting mechanism and at least partly surrounds said ram, the guide beam is disposed beneath the ram housing and is positioned to rest on the floor of a mine working during use;
• independent guide means acting between the guide beam and the ram housing serves to guide the ram housing and the guide beam for relative movement predominantly longitudinally of the floor sills while permitting vertical and tilting adjustments between the guide beam and the ram housing and respective connection means connects the ram to the ram housing, for vertical displacement therewith and connects the ram to the guide beam whereby to maintain the guide beam in contact with the floor of the mine working;
• wherein the guide means comprises a guide rail partly received in a guide element with clearance therebetween, the guide rail and the guide element being positioned at the central region of the space between the floor sills;
• the guide rail is mounted on the lower side of the ram housing and the guide element is mounted on the upper side of the guide beam, wherein the guide rail extends approximately half way along the bottom of the ram housing and the guide element approximately half way along the guide beam, and wherein the guide rail is disposed over the part of the ram housing at the front relative to the direction of advancement.