GB879784A - Releasable coupling for ventilation pipes, particularly for air ducts in mines - Google Patents

Abstract

879,784. Pipe couplings. THELEMANN, F., and HAUSMANN, B. Oct. 14, 1958, No. 32722/58. Class 99(1). A releasable coupling for ventilation pipes, such as air ducts in mines, comprises in each of the adjacent ends of wooden pipes 1, 2 a metal or synthetic plastic annular member 3 having a cylindrical main portion 3<SP>2</SP> secured by screws or rivets to the inner side of the pipe and a circumferential flange 3<SP>1</SP> projecting outwardly from the portion 3<SP>2</SP> and having its free edge bent round to form an annular bead in engagement with the outer side of the pipe, a rubber or synthetic plastic sleeve 5 encircling the pipe ends and the members 3 and surrounded by a retaining strap 6, e.g. of metal, of dome-shaped or convex cross-section having beaded edges 6<SP>2</SP> which are urged by a toggle-type closing mechanism 7 into tight engagement with the sleeve 5 to form a leakproof connection between the pipes 1, 2. As shown, the sleeve 5 is of semi-circular crosssection and has its peripheral edges provided with annular dovetail-shaped beads 51 projecting inwardly and outwardly of the sleeve 5 and having grooved sealing surfaces 5<SP>2</SP>, the inward projections of the beads being acted upon by fluid pressure and the outward projections by the beaded edges 6<SP>2</SP>. The sleeve 5 fits snugly in the strap 6 being held therein by the beaded edges 6<SP>2</SP>. Alternatively, the sleeve 5 is permanently connected to the strap 6 by vulcanizing or by an adhesive. In a modification the sleeve 5 is replaced by a plain rubber tubular sleeve embracing the flanges 3<SP>1</SP> of the member 3 and held in position on the pipe ends by elastic action. The ends of the strap 6 are filleted so that the beaded edges 6<SP>2</SP> slide one within the other, and center themselves as the strap is tightened around the pipes.