Prop device for mining and tunnel construction

Prop device according to one of the previous claims,

• characterized by the fact
• that the outer and inner pipes (2, 3) are designed to allow a continuously variable extension of 300-500 mm.

Prop device according to one of the previous claims,

• characterized by the fact
• that the plate (10) corresponds with the inner pipe (2) and features a weak point (18) which bursts when the allowed filling pressure in the outer pipe (3) is exceeded.

Prop device according to one of the previous claims,

• characterized by the fact
• that the plate (10) is made out of rubber or compatible work material and features a weak point (18) in the middle.

Prop device according to one of the previous claims,

• characterized by the fact
• that the outer pipe (3) and the footer plate (7) are linked with each other via a welded seam (19).

Prop device according to one of the previous claims,

• characterized by the fact
• that the head plate (5) is attached to the inner pipe (2) on several, preferably three fixating points (20).

Prop device according to one of the previous claims,

• characterized by the fact
• that the head (14) of the outer pipe (3) features a slope (22) on the side facing the inner pipe (2) which corresponds with the wedges (8) whereas the sides (23, 24) of the wedge (8) and the inner pipe (2) that connect with each other run vertical and parallel towards each other.

Prop device according to one of the previous claims,

• characterized by the fact
• that between the upper edge (26) of the wedges (8) and the bottom (27) of the header plate (5) a cylinder spring (28) is positioned which acts as a place holder (15).

Prop device according to one of the previous claims,

• characterized by the fact
• that the upper end (29) of the sides (23, 24) of the wedges (8) and/or the outer wall (30) of the inner pipe (2) is equipped with a saw tooth thread (31).

Prop device according to one of the previous claims,

• characterized by the fact
• that the head (14) of the outer pipe (3) is shaped as a pot and is connected via a weld (32) with the upper end piece (33) of the outer pipe (3).

Prop device according to one of the previous claims,

• characterized by the fact
• that the header plate (5) as well as the footer plate (7) feature cams (38, 39) which extend over the outer surface (37).

Prop device according to one of the previous claims,

• characterized by the fact
• that the wedge (8) consists of three partial wedges (40, 41, 42) which are held in place and positioned in a distance to each other by a holding wire (43).

Prop device according to one of the previous claims,

• characterized by the fact
• that the partial wedges (40, 42, 42) are held in a distance to each other by a holding wire (43) which features indentations (44) that pre-determine the distance.