Advanceable mine roof supports

In an advanceable roof support comprising a floor engaging structure, a roof engaging structure, telescopic props disposed between the roof and floor engaging structures, the floor engaging structure being composed of a pair of laterally-spaced apart floor sills;

• shifting means at least partly between the sills, the shifting means being composed of an hydraulic ram and thrust means operably connected in an articulated manner to the floor sills and being adapted for connection in an articulated manner to an advance abutment, such as a conveyor, adjacent the support, means interconnecting the floor sills to permit relative vertical displacement therebetween, elongate guides on adjacent sides of the floor sills and a guide connected to the shifting means slidably engaged with the elongate guides whereby the ram can be operated to extend or retract to displace the support forwardly relative to the advance abutment or to displace the advance abutment away from the support in an advancing direction with the aid of the thrust means and the shifting means is guided by relative displacement between the guide and the guide rails;
• the improvement comprising the guide is connected to the shifting means by a pivot joint with an axis extending in the direction of advancement, said pivot joint including a pivot pin fixed to the guide and engaging in an opening in a component of the shifting means, said opening having a circular portion adjoining one or more radial recesses, and the pivot pin having one or more locking lugs which pass through the recess or recesses when the pin is in a certain orientation to permit assembly of the pivot joint.

In an advanceable roof support comprising a floor engaging structure, a roof engaging structure, telescopic props disposed between the roof and floor engaging structures, the floor engaging structure being composed of a pair of laterally-spaced apart floor sills;

• shifting means at least partly between the sills, the shifting means being composed of an hydraulic ram and thrust means operably connected in an articulated manner to the floor sills and being adapted for connection in an articulated manner to an advance abutment, such as a conveyor, adjacent the support, means interconnecting the floor sills to permit relative vertical displacement therebetween, elongate guides on adjacent sides of the floor sills and a guide connected to the shifting means slidably engaged with the elongate guides whereby the ram can be operated to extend or retract to displace the support forwardly relative to the advance abutment or to displace the advance abutment away from the support in an advancing direction with the aid of the thrust means and the shifting means is guided by relative displacement between the guide and the guide rails;
• the improvement comprising the guide is connected to the shifting means by a pivot joint with an axis extending in the direction of advancement, said pivot joint including a pivot pin fixed to a component of the shifting means and engaging in an opening in the guide, said opening having a circular portion adjoining one or more radial recesses, and the pivot pin have one or more locking lugs which pass through the recess or recesses when the pin is in a certain orientation to permit assembly of the pivot joint.

In an advancement roof support comprising a floor engaging structure, a roof engaging structure, telescopic props disposed between the roof and floor engaging structures, the floor engaging structure being composed of a pair of laterally-spaced apart floor sills;

• shifting means at least partly between the sills, the shifting means being composed of an hydraulic ram and thrust means operably connected in an articulated manner to the floor sills and being adapted for connection in an articulated manner to an advance abutment, such as a conveyor, adjacent the support, means interconnecting the floor sills to permit relative vertical displacement therebetween, elongate guides on adjacent sides of the floor sills and a guide connected to the shifting means slidably engaged with the elongate guides whereby the ram can be operated to extend or retract to displace the support forwardly relative to the advance abutment or to displace the advance abutment away from the support in an advancing direction with the aid of the thrust means and the shifting means is guided by relative displacement between the guide and the guide rails;
• the improvement comprising the guide is connected to the shifting means by a pivot joint with an axis extending in the direction of advancement, and the thrust means incorporates a pair of resilient thrust rods extending partly between upper and lower plates remote from the guide, and hydraulic piston and cylinder units are provided to partly lift the floor sills when the support is to be advanced wherein the units rest on the upper plates and are coupled to the floor sills.

In an advanceable roof support comprising a floor engaging structure, a roof engaging structure, telescopic props disposed between the roof and floor engaging structures, the floor engaging structure being composed of a pair of laterally-spaced apart floor sills;

• shifting means at least partly between the sills, the shifting means being composed of an hydraulic ram and thrust means operably connected in an articulated manner to the floor sills and being adapted for connection in an articulated manner to an advance abutment, such as a conveyor, adjacent the support, means interconnecting the floor sills to permit relative vertical displacement therebetween, elongate guides on adjacent sides of the floor sills and a guide connected to the shifting means slidably engaged with the elongate guides whereby the ram can be operated to extend or retract to displace the support forwardly relative to the advance abutment or to displace the advance abutment away from the support in an advancing direction with the aid of the thrust means and the shifting means is guided by relative displacement between the guide and the guide rails;
• the improvement comprising the guide is connected to the shifting means by a pivot joint with an axis extending in the direction of advancement, the thrust means takes the form of a floor beam, and hydraulic piston and cylinder units rest on said beam and are coupled to the floor sills, said units serving to partially lift the floor sills when the support is to be advanced.