Shock absorber

Claim 2

A hydraulic shock absorber comprising: a hollow cylinder (30) defining therein a fluid chamber (42) filled with a working fluid; a piston (32) slidably disposed within said fluid chamber to divide the fluid chamber into upper (44) and lower chambers (46) and having upper and lower members (48, 50) assembled together for defining therein a vortex chamber (68, 70), said upper and lower members being formed with vertically extending recesses (56, 58) on the periphery thereof, the recesses formed in the upper and lower members being aligned with respect to one another and defining vertical vortex passages, said piston further defining vortex passages (64, 66) having inner ends tangentially opening into said vortex chamber and outer ends opening into said vertical vortex passages; and means (84; 86, 88) for establishing communication between at least one of said upper and lower chambers, and said vortex chamber.

Claim 3

A hydraulic shock absorber comprising: a hollow cylinder (30) defining therein a fluid chamber (42) filled with a working fluid; an upper piston (48) member secured onto the lower end of a pistion rod (34) for motion therewith and having a circular cavity (68) opening downwardly and having vertical recesses (56) extending along the outer periphery thereof; a lower piston member (50) secured to the lower end of said upper piston member and constituting therewith a piston which divides the fluid chamber (42) within said cylinder into upper and lower chambers (44, 46), said lower piston member sealingly closing the lover end of said cavity of said upper piston member for defining therein a vortex chamber and having recesses (58) in alignment with said recesses of said upper piston member, said aligned recesses defining vertical vortex passages along the internal periphery of the fluid chamber; a pair of vortex passages (64, 66) provided in said upper piston member, said vortex passages tangentially opening into said vortex chamber at the inner ends thereof and opening into said vertical vortex passages at the outer ends; and means (84, 86, 88) for establishing communication between each of said upper and lower chambers and said vortex chamber.

Claim 4

A hydraulic shock absorber comprising: a hollow cylinder (30) defining therein a fluid chamber (42) filled with a working fluid; an upper piston (48) member secured onto the lower end of a pistion rod (34) for motion therewith and having a circular cavity (68) opening downwardly and having vertical recesses (56) extending along the outer periphery thereof; a lower piston member (50) secured to the lower end of said upper piston member and constituting therewith a piston which divides the fluid chamber (42) within said cylinder into upper and lower chambers (44, 46), said lower piston member sealingly closing the lover end of said cavity of said upper piston member for defining therein a vortex chamber and having recesses (58) in alignment with said recesses of said upper piston member, said aligned recesses defining vertical vortex passages along the internal periphery of the fluid chamber; a pair of vortex passages (64, 66) provided in said upper piston member, said vortex passages tangentially opening into said vortex chamber at the inner ends thereof and opening into said vertical vortex passages at the outer ends; and means (84, 86, 88) for establishing communication between each of said upper and lower chambers and said vortex chamber.

Claim 5

A shock absorber as set forth in claim 1 or 2, wherein said vortex chamber is divided into upper and lower sections (68, 70) with a partition (67) sealingly disposed within said vortex chamber, said upper and lower sections communicating with each other via said vertical vortex passages (56, 58) and vortex passages (64, 66).

Claim 6

A shock absorber as set forth in claim 3, wherein said upper chamber (44) of said fluid chamber (42) communicates with said upper section (68) of said vortex chamber via said communication means and said lower chamber (46) communicates with said lower section (70) of said vortex chamber via said communication means.

Claim 7

A shock absorber as set forth in claim 4, wherein said communication means includes a narrowed cross-sectional area for limiting the flow of the fluid therethrough.

Claim 8

A'.shock absorber as set forth in claim 3, wherein said partition (67) is made of a flexible material and deformable in response to the fluid pressure applied thereto.

Claim 9

A shock absorber as set forth in claim 6, wherein said partition incorporates a relief valve (230) for relieving the fluid pressure in said vortex chamber, whereby the absorbing force produced by said vortex chamber is limited in the ranges of extreme fluid pressure.

Claim 10

A shock absorber as set forth in claim 7, wherein said relief valve comprises a pair of apertures (238, 240) formed in said partition and a pair of resilient members (232, 234) fitted on opposite surfaces of the partition, one of said resilient members closing some of said apertures and the other closing the other apertures on the opposite side, said resilient members providing resilient force serving as a set pressure for the relief valve.

Claim 11

A shock absorber as set forth in claim 4, wherein a tubular member (98) is inserted into said vertical vortex passage (56, 58) and vortex passages (64, 66) for establishing communication between said upper and lower sections of said vortex chamber.

Claim 12

A shock absorber as set forth in claim 1 or 2, wherein said means for establishing communication between each of said upper and lower fluid chambers (44, 46) and said vortex chamber (68, 70) incorporates a fluid-pressure- responsive valve means (194, 204) for blocking communication between each of said upper and lower fluid chambers and said vortex chamber in response to the fluid pressure exceeding a predetermined value.

Claim 13

A shock absorber as set forth in claim 1 or 2, wherein said means for establishing communication between at least one of said upper and lower fluid chambers (44, 46) and said vortex chamber (68, 70) incorporates means for reducing the cross-sectional area permitting fluid flow said means for reducing the area being a tubular member (189) inserted therein.