Abstract: A pipe coupling for connecting together two plain-ended pipes in a fluid-tight manner comprises an outer tubular casing, an inner tubular casing and a tubular sealing sleeve. The sealing sleeve has two sets of inwardly projecting ribs which, in use, are pressed into sealing engagement with the respective ends of the pipes. The inner and outer casings are longitudinally split and tensioning screws on the outer casing can be tightened to tighten the outer casing around the inner casing and the sealing sleeve. Frustoconical slots in the outer surfaces of the sealing sleeves receive frustoconical gripping rings which have gripping teeth on the inner sides which bite into the pipe surfaces to secure the pipes against axial displacement.

Abstract: A resiliently flexible pipe coupling for interconnecting two pipe ends in a pressure-tight manner includes a tubular sealing sleeve of resilient flexible material, and an adjustable tubular metal casing for clamping the sealing sleeve around the pipe ends. The sealing sleeve includes a tubular web portion and sealing lips integral with the web portion. The sealing lips are formed in adjoining relationship relative to the web portion and define free ends of the sealing sleeve. The sealing lips extend radially inwardly from the web portion and are spaced apart longitudinally. Each sealing lip includes a radially inner pipe-engaging surface for engaging one of the pipe ends, and the pipe-engaging surface of one of the lips has a substantially different internal diameter from the pipe-engaging surface of the other lip, whereby the coupling is adapted to connect two pipe ends of different external diameter.

Abstract: A resilient flexible pipe coupling for interconnecting two pipes of different diameters in a pressure tight manner comprises a tubular metal casing formed with a longitudinal gap and a tensioning screw device for reducing the width of the gap to tighten the coupling around the adjacent ends of the two pipes. A sealing sleeve of resilient flexible material is arranged within the casing. The sleeve has radially inwardly projecting sealing lips formed on both of its free end. The sealing lips have different radial thicknesses so as to compensate for the difference in diameters of the pipes.