GB1130037A - Improvements in or relating to rolling diaphragms - Google Patents

Abstract

1,130,037. Seals. PHILIPS' GLOEILAMPENFABRIEKEN N.V. 9 Dec., 1965 [12 Dec., 1964], No. 52272/65. Headings F2B and F2T. A rolling sleeve-type seal for use between a piston and a cylinder or between a reciprocable rod and a housing'comprises a plurality of layers of elastic material which are connected to one another at their edges or over their entire area. The layers when connected to one another only at their edges may have different lengths so that when the seal is mounted in position, the inner edges lie in one plane and the outer edges also lie in one plane. When secured to one another over their entire area, they may be prestressed beforehand, the innermost layer to a greater extent than the outermost layer. The innermost layer may be subjected to' a tensile stress and the outermost layer to a compressive stress. One or more of the layers may be made of a material different from that of the other layers. The concave or the convex side of the sleeve may face the working space. Fig. 5 shows a rolling sleeve-type seal 3 between a piston 1 and a cylinder 2. The layers are secured to one another only at their edges. A lubricant may be provided between the layers to increase the flexibility of the seal and reduce internal friction and wear. The seal is supported on its convex side, remote from the working space 4, by a liquid contained in an annular space 5 which, due to the construction of the piston and cylinder, is kept constant during the operation of the piston so that the pressure differential across the diaphragm once adjusted will not vary.