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US4418802A Expired / Lapsed US ⏱️ 0.0 years remaining

Shock absorber

Assignee: Nissan Motor Co Ltd
•
Filing: 1981-07-20
•
Granted: 1983-12-06
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Expires: 2001-07-20
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Abstract

Abstract A hydraulic shock absorber including a piston disposed within a hollow cylinder in movable position responsive to a shock applied thereto, the piston defining a hollow vortex chamber therein, the vortex chamber being communicated with fluid chambers defined in the hollow cylinder to introduce a working fluid and to generate a vortex therein for producing an absorbing force, wherein the vortex chamber being so sized as 1≦(h·Sv/So)≦6 where: h is a depth of the vortex chamber; Sv is sectional area of the vortex chamber; So is effective sectional area of the piston effecting for the fluid to increase or decrease the pressure thereof.

Inventors

  • 👤 Naoto Fukushima
  • 👤 Kazuroh Iwata
  • 👤 Kunihiko Hidaka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 01:49
CPC Classifications
F; F16; F16F; F16F9/00; F16F9/32; F16F9/34; F16F9/344; B; B60; B60G; B60G13/00; B60G13/02; B60G13/06; B60G13/08

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 111 words
A hydraulic shock absorber including a piston disposed within a hollow cylinder in movable position responsive to a shock applied thereto, said piston defining a hollow vortex chamber therein, said vortex chamber being communicated with fluid chambers defined in the hollow cylinder to introduce a working fluid and to generate a vortex-type fluid flow therein for producing an absorbing force, wherein the vortex chamber is sized to satisfy the specific relationship 1≦h·Sv/So≦6 where: h is the depth of the vortex chamber; Sv is the cross-sectional area of the vortex chamber; and So is the effective cross-sectional area of the piston acting on the fluid to increase or decrease the pressure thereof.
Claim 2
Dependent Claim 111 words
A hydraulic shock absorber including a piston disposed within a hollow cylinder in movable position responsive to a shock applied thereto, said piston defining a hollow vortex chamber therein, said vortex chamber being communicated with fluid chambers defined in the hollow cylinder to introduce a working fluid and to generate a vortex-type fluid flow therein for producing an absorbing force, wherein the vortex chamber is sized to satisfy the specific relationship 1≦h·Sv/So≦6 where: h is the depth of the vortex chamber; Sv is the cross-sectional area of the vortex chamber; and So is the effective cross-sectional area of the piston acting on the fluid to increase or decrease the pressure thereof.
Claim 3
Dependent Claim 42 words
A shock absorber as set forth in claim 1, wherein said piston defines two vortex chambers therein, said vortex chambers communicating with one another and having depths and cross-sectional areas related to the effective area of the piston in said specific relationship.
Claim 4
Dependent Claim 50 words
A shock absorber as set forth in claims 1 or 2, wherein said cylinder further includes a pneumatic chamber filled with a gas, the volume of said pneumatic chamber being variable so that it can absorb variation in fluid pressure caused by varying of the displacement of the piston rod.
Claim 5
Dependent Claim 147 words
A hydraulic shock absorber for an automotive vehicle suspension for damping relative displacement of the vehicle body and vehicle wheel, comprising: a hollow cylinder defining therein a fluid chamber filled with a working fluid; a piston disposed within said fluid chamber and dividing said fluid chamber into upper and lower sections, said piston being movable along the longitudinal axis of said cylinder in response to the shock applied to the shock absorber; a piston rod connecting said piston to said vehicle body; and a vortex chamber defined within said piston and communicated with said upper and lower sections of the fluid chamber, said vortex chamber having a sectional area and a depth satisfying the following equation: ##EQU1## in which r 1 is the external radius of the piston; r 2 is the radius of the vortex chamber; and r 3 is the radius of a piston rod.
Claim 6
Dependent Claim 147 words
A hydraulic shock absorber for an automotive vehicle suspension for damping relative displacement of the vehicle body and vehicle wheel, comprising: a hollow cylinder defining therein a fluid chamber filled with a working fluid; a piston disposed within said fluid chamber and dividing said fluid chamber into upper and lower sections, said piston being movable along the longitudinal axis of said cylinder in response to the shock applied to the shock absorber; a piston rod connecting said piston to said vehicle body; and a vortex chamber defined within said piston and communicated with said upper and lower sections of the fluid chamber, said vortex chamber having a sectional area and a depth satisfying the following equation: ##EQU1## in which r 1 is the external radius of the piston; r 2 is the radius of the vortex chamber; and r 3 is the radius of a piston rod.
Claim 7
Dependent Claim 176 words
A hydraulic shock absorber for an automotive vehicle suspension for damping relative displacement between the vehicle body and the vehicle wheel, comprising: a hollow cylinder defining a fluid chamber filled with a working fluid; a piston disposed within said fluid chamber and dividing said fluid chamber into upper and lower sections, said piston being movable along the longitudinal axis of said cylinder in response to the load applied to said vehicle body and/or vehicle wheel; an upper vortex chamber defined in said piston and adapted to create vortex-fashion fluid flow in the piston compression stroke; a lower vortex chamber defined in said piston and adapted to create vortex-fashion fluid flow in the piston expansion stroke; a piston rod connecting said piston to said vehicle body; and each of said vortex chambers having a sectional area and a depth so as to satisfy the following equation: ##EQU2## in which r 1 is the external radius of the piston; r 2 is the radius of the vortex chamber; and r 3 is the radius of a piston rod.
Claim 8
Dependent Claim 176 words
A hydraulic shock absorber for an automotive vehicle suspension for damping relative displacement between the vehicle body and the vehicle wheel, comprising: a hollow cylinder defining a fluid chamber filled with a working fluid; a piston disposed within said fluid chamber and dividing said fluid chamber into upper and lower sections, said piston being movable along the longitudinal axis of said cylinder in response to the load applied to said vehicle body and/or vehicle wheel; an upper vortex chamber defined in said piston and adapted to create vortex-fashion fluid flow in the piston compression stroke; a lower vortex chamber defined in said piston and adapted to create vortex-fashion fluid flow in the piston expansion stroke; a piston rod connecting said piston to said vehicle body; and each of said vortex chambers having a sectional area and a depth so as to satisfy the following equation: ##EQU2## in which r 1 is the external radius of the piston; r 2 is the radius of the vortex chamber; and r 3 is the radius of a piston rod.
Claim 9
Dependent Claim 95 words
A shock absorber as set forth in claim 5, wherein said upper and lower vortex chambers respectively communicated with said upper and lower sections of the fluid chamber, said piston further defines a fluid passage extending along the circumferencial periphery thereof and a vortex passage having an inner end opening toward one of said vortex chambers in the direction substantially along the normal of the circle of the vortex chamber and the outer end opening toward the fluid passage, said fluid passage and the vortex passage establishing communication between said upper and lower vortex chambers.
Claim 10
Dependent Claim 38 words
A shock absorber as set forth in claim 6, wherein said cylinder further defines therein a pneumatic chamber filled with a gas, the volume of said pneumatic chamber being variable corresponding to the displacement of the piston rod.

References Cited (Backward Citations)

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FR845638A Cited
FR892773A Cited
GB600386A Cited
FR993852A Cited
US3133615A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-12-05 1987-06-06 1987-12-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-12-05 1991-06-06 1991-12-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-12-05 1995-06-06 1995-12-06 $7700.00 Window Closed / Lapsed

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