Mine stopping panel and method of manufacture

A mine stopping panel comprising

• a first elongate panel member and a second elongate panel member, each panel member having a web, and first and second flanges at opposite sides of the web,
• said first and second panel members having a telescoping sliding fit one of said first and second panel members inside the other of said first and second panel members along an axis extending lengthwise of the panel members,
• a first end cap extending between the first and second flanges of the first panel member on an inside surface of the web of the first panel member,
• at least one louver connection between the first panel member and the first end cap holding the first end cap against movement relative to the first panel member when an extending force is applied to the first end cap tending to telescopically extend the first panel member relative to the second panel member in a first direction along said axis, and
• at least one first device on the first end cap configured for engagement with the first panel member to resist telescopic movement of the first end cap relative to the first panel member when a contracting force is applied to the first end cap tending to telescopically contract the first panel member relative to the second panel member in a second direction along said axis opposite said first direction;
• wherein said at least one louver connection comprises a louver projecting through a louver opening;
• wherein the louver of said at least one louver connection has a louver body having a surface positioned for engagement by an opposing edge of said louver opening when said extending force is applied to the first end cap, said surface of the louver body comprising a free edge opposite a base edge of the louver body joined to the first end cap, said free edge including an elevated segment and end segments on opposite sides of the elevated segment depressed toward the base edge relative to the elevated segment to define a slot for receiving said opposing edge of said louver opening, said slot extending between the end segments of the free edge and having slot end portions sized for receiving said opposing edge of said louver opening, the slot end portions at the end segments of the free edge being recessed into the louver body toward the base edge relative to the elevated segment of the free edge, the louver body having a height measured parallel to the axis, the height extending from the base edge to the elevated segment of the free edge such that the louver body overlaps the opposing edge of the louver opening in a heightwise direction of the louver body parallel to said axis when the opposing edge of the louver opening is received in said slot.