Patent GB-981607-A (GB)
Title: Sealing and guiding arrangement for pistons in cylinders operating with hydraulic or pneumatic pressure media
Inventor: EICKMANN KARL
IPC: F16J10/02
Filed: 1961-02-28
Abstract: 981,607. Pistons; stuffing-boxes; seals; circlips. R. BREINLICH. Feb. 28, 1961, No. 7209/61. Headings F2B, F2H and F2T. The piston-rod 6 of a piston 7, Fig. 1, of an hydraulic or pneumatic machine is guided in a cylinder by a bush 2 secured against axial movement firstly by means of a locking ring 3, e.g. a spring ring, located in an annular groove or recess in the inner surface of the cylinder and engaging an annular shoulder of the bush remote from the inner end thereof, or, as shown in Fig. 7, engaging a spacing ring 13 which bears on the outer end of the bush 2, and secondly by retaining means, e.g. a spring ring 22, Fig. 1, or 62, Fig. 7, the whole or part of which projects radially into the bush remote from its inner end. In Fig. 1, the bush 2 extends out of the cylinder to provide an inlet conduit 30 for the pressure fluid which is transmitted to the piston through axial ducts 14. The end of the extended portion of the bush is sealed to the cylinder by packing 24 and to the piston rod by a lipped packing 25. Located in a recess 18 in the bush 2 between the spring rings 3 and 22 are segmented rings 19, 20, the latter ring being held by a cover sleeve 21 bearing against the ring 22. The piston 7 may consist of one or, as shown, two parts and is secured to the rod 6 by a divided ring 9 and by spring rings 12 through the interposition of gaskets 8 and thrust washers 11. Alternatively, the rings 12 bear directly against the piston parts, or the washers are provided with beads engaging in grooves in the piston rod and may bear against piston annular projecting parts defining a pair of annular recesses on both sides of the piston for the reception of annular gaskets. In a modification of Fig. 1, the guiding bush is made of two concentric parts held together by spring rings and the inlet conduit for the pressure medium is provided in the outer part. In Fig. 4, two guide bushes 2, 36 are provided spaced from each other and the bush 2 is secured by a sleeve 37 and a ring 35, the latter being divided into sectors separated by balls or rollers; a dust preventive gasket 38 is provided around the piston-rod 6. In Fig. 7, the bush 2 is locked in the axial direction towards the pressure side by a spring ring 62 bevelled at one side and engaging in recesses in the bushing and cylinder; alternatively, the ring 62 is bevelled at both sides and has a pointed (Fig. 10) or rounded (Fig. 8) central portion, or the ring is of circular cross-section. In Fig. 10, the ring 13 is secured by a divided ring 35 inserted in an annular recess in a ring 77 which is in turn secured by a spring ring 3. In Fig. 14, the bush 2 is secured by a divided ring 35 and a sleeve 37 which is retained by the flanged end 96 of the bush; alternatively, the sleeve is integral with the ring 35 and/or is held by a spring ring in the bush. In further embodiments, (a) a reduced diameter portion of the cylinder is deformed in a recess in the bush; (b) the bush and cylinder are secured by a rivet and plug assembly; (c) interfitting parts of the bush and an end closure ring for the cylinder are secured by a bolt engaging in corresponding bores in the parts, or the bushing is deformed in a recess in the ring. Specification 871,900 is referred to.