US3865356A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic shock absorber
Assignee: ZF Friedrichshafen AG
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Filing: 1973-06-14
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Granted: 1975-02-11
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Expires: 1993-06-14
Abstract
Abstract A hydraulic shock absorber for use between a bumper and frame of an automotive vehicle has a cylinder, a piston formed with throttling passages closed by a spring-loaded valve until an applied axial force reaches a predetermined value, and the opened valve permits liquid flow through the piston, and a chamber filled with gas under pressure and separated from the liquid by an axially movable partition. The gas pressure tends to drive the piston rod outward of the cylinder cavity, but cannot normally exert a force equal to the valve-opening force. The characteristics of the shock absorber are partly determined by various arrangements for transmitting to the cylinder a small axial force applied to the piston rod without opening the throttling passages.
Inventors
- 👤 Felix Wossner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:31
CPC Classifications
F; F16; F16F; F16F9/00; F16F9/06; F16F9/066; F16F9/067; B; B60; B60R; B60R19/00; B60R19/02; B60R19/24; B60R19/26; B60R19/32
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
219 words
A shock absorber for use between a bumper and the frame of an automotive vehicle comprising: a. a cylinder having an axis and bounding a cavity therein; b. a piston axially movable in said cylinder and axially separating a first and a second compartment of said cavity; c. a piston rod fastened to said piston in said cavity and axially extending outward of said cylinder; d. fastening means for respectively fastening said cylinder and said piston rod to said bumper and to said frame respectively; e. a liquid substantially completely filling said compartments; f. normally closed throttling valve means responsive to movement of said piston rod in a direction inward of said cylinder under a predetermined axial force applied by said fastening means for opening a throttliNg passage between said compartments; g. partition means axially movable in said cylinder and separating one of said compartments from a chamber in said cavity; h. a body of gas substantially filling said chamber under a pressure sufficient for biasing said piston rod outward of said cavity in at least one axial position of said piston rod with a force smaller than said predetermined force; and i. force transmitting means for transmitting to said cylinder an axial force applied to said piston rod in said inward direction and smaller than said predetermined force.
Claim 2
Dependent Claim
219 words
A shock absorber for use between a bumper and the frame of an automotive vehicle comprising: a. a cylinder having an axis and bounding a cavity therein; b. a piston axially movable in said cylinder and axially separating a first and a second compartment of said cavity; c. a piston rod fastened to said piston in said cavity and axially extending outward of said cylinder; d. fastening means for respectively fastening said cylinder and said piston rod to said bumper and to said frame respectively; e. a liquid substantially completely filling said compartments; f. normally closed throttling valve means responsive to movement of said piston rod in a direction inward of said cylinder under a predetermined axial force applied by said fastening means for opening a throttliNg passage between said compartments; g. partition means axially movable in said cylinder and separating one of said compartments from a chamber in said cavity; h. a body of gas substantially filling said chamber under a pressure sufficient for biasing said piston rod outward of said cavity in at least one axial position of said piston rod with a force smaller than said predetermined force; and i. force transmitting means for transmitting to said cylinder an axial force applied to said piston rod in said inward direction and smaller than said predetermined force.
Claim 3
Dependent Claim
68 words
A shock absorber as set forth in claim 1, wherein said cylinder has an imperforate radial end wall axially bounding said cavity and said first compartment, the liquid in said first compartment constituting said force transmitting means, said partition means separating said second compartment from said chamber, and said piston rod extending axially from said piston through said second compartment and said chamber and outward of said cavity.
Claim 4
Dependent Claim
62 words
A shock absorber as set forth in claim 1, wherein said cylinder has an imperforate radial end wall axially bounding said cavity and said chamber, said body of gas constituting said force transmitting means, said partition means separating said first compartment from said chamber, and said piston rod extending axially from said piston through said second compartment and outward of said cavity.
Claim 5
Dependent Claim
63 words
A shock absorber as set forth in claim 1, wherein said cylinder has an imperforate radial end axially bounding said cavity and said chamber, said partition means separating said first compartment from said chamber, and said force transmitting means include abutment means in said cavity for limiting comprises of said body by relative axial movement of said partition means and of said cylinder.
Claim 6
Dependent Claim
25 words
A shock absorber as set forth in claim 4, wherein said abutment means include respective rigid abutments on said partition means and on said cylinder.
Claim 7
Dependent Claim
27 words
A shock absorber as set forth in claim 5, wherein said cylinder is formed with a shoulder in said cavity, said shoulder constituting one of said abutments.
Claim 8
Dependent Claim
32 words
A shock absorber as set forth in claim 5, wherein one of said abutments is constituted by an axial projection of said partition means axially opposite an abutment face of said cylinder.
Claim 9
Dependent Claim
18 words
A shock absorber as set forth in clalim 4, wherein said abutment means include a yieldably resilient abutment.
Claim 10
Dependent Claim
18 words
A shock absorber as set forth in clalim 4, wherein said abutment means include a yieldably resilient abutment.
Claim 11
Dependent Claim
23 words
A shock absorber as set forth in claim 8, wherein said abutment is a body of elastomeric material mounted on said end wall.
Claim 12
Dependent Claim
28 words
A shock absorber as set forth in claim 8, wherein said abutment includes a stack of cup springs interposed axially between said partition means and said end wall.
Claim 13
Dependent Claim
231 words
A shock absorber for use between a bumper and the frame of an automotive vehicle comprising: a. a cylinder having an axis and bounding a cavity therein; b. a piston axially movable in said cylinder and axially separating a first and a second compartment of said cavity; c. a piston rod fastened to said piston in said cavity and axially extending outward of said cylinder; d. fastening means for respectively fastening said cylinder and said piston rod to said bumper and to said frame respectively; e. a liquid contained in said compartments adjacent said piston; f. a throttling passage between said compartments for passage of liquid responsive to movement of said piston rod in a direction inward of said cylinder under a predetermined axial force applied by said fastening means; g. a chamber in said cavity; h. a body of gas substantially filling said chamber under a pressure sufficient for biasing said piston rod outward of said cavity in at least one axial position of said piston rod with a force smaller than said predetermined force; and i. force transmitting means for transmitting to said cylinder an axial force applied to said piston rod in said inward direction, said force transmitting means being at least partIally independent of said body of gas over at least part of the stroke of said piston rod between its outermost position and its innermost position.
Claim 14
Dependent Claim
231 words
A shock absorber for use between a bumper and the frame of an automotive vehicle comprising: a. a cylinder having an axis and bounding a cavity therein; b. a piston axially movable in said cylinder and axially separating a first and a second compartment of said cavity; c. a piston rod fastened to said piston in said cavity and axially extending outward of said cylinder; d. fastening means for respectively fastening said cylinder and said piston rod to said bumper and to said frame respectively; e. a liquid contained in said compartments adjacent said piston; f. a throttling passage between said compartments for passage of liquid responsive to movement of said piston rod in a direction inward of said cylinder under a predetermined axial force applied by said fastening means; g. a chamber in said cavity; h. a body of gas substantially filling said chamber under a pressure sufficient for biasing said piston rod outward of said cavity in at least one axial position of said piston rod with a force smaller than said predetermined force; and i. force transmitting means for transmitting to said cylinder an axial force applied to said piston rod in said inward direction, said force transmitting means being at least partIally independent of said body of gas over at least part of the stroke of said piston rod between its outermost position and its innermost position.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |