Patent US3195829A successfully refreshed from Google Patents.
Patent US3871678A successfully refreshed from Google Patents.
US3871678A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suspension units for vehicles
Assignee: Girling Ltd
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Filing: 1973-11-15
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Granted: 1975-03-18
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Expires: 1993-11-15
Abstract
Abstract In a self-levelling hydro-pneumatic suspension unit for a vehicle operation of an inlet valve controlling liquid flow into the unit through an inlet is controlled by resilient means in association with an assembly comprising a piston working in a cylinder and a piston-rod carrying the piston.
Inventors
- 👤 Philip Augustus Taft
- 👤 Stuart Bruce Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:21
CPC Classifications
B; B60; B60G; B60G15/00; B60G15/08; B60G15/12; B60G17/00; B60G17/02; B60G17/04; B60G17/048
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
187 words
An hydro-pneumatic suspension unit of the self-levelling type for a vehicle comprising a cylinder, a closure for one end of said cylinder, a piston-rod assembly defined by a piston adapted to work in said cylinder, and a piston-rod carrying said piston and adapted to work through said closure, a pressure chamber containing gas for supporting a load on the unit, an inlet for connection to a source of high pressure liquid, an inlet valve incorporated in said closure for controlling liquid flow through said inlet into the unit, means for maintaining the effective length of the unit at a predetermined value irrespective of the load, resilient means acting in association with said piston-rod assembly to control operation of said inlet valve, and a collapsible sub-assembly incorporating said resilient means to limit the maximum effective length which said resilient means can attain, said sub-assembly being engageable with said inlet valve to close said inlet valve when the effective length of said unit attains a predetermined extended value, further extension of said unit beyond the said extended value being opposed by said resilient means after collapse of said sub-assembly.
Claim 2
Dependent Claim
187 words
An hydro-pneumatic suspension unit of the self-levelling type for a vehicle comprising a cylinder, a closure for one end of said cylinder, a piston-rod assembly defined by a piston adapted to work in said cylinder, and a piston-rod carrying said piston and adapted to work through said closure, a pressure chamber containing gas for supporting a load on the unit, an inlet for connection to a source of high pressure liquid, an inlet valve incorporated in said closure for controlling liquid flow through said inlet into the unit, means for maintaining the effective length of the unit at a predetermined value irrespective of the load, resilient means acting in association with said piston-rod assembly to control operation of said inlet valve, and a collapsible sub-assembly incorporating said resilient means to limit the maximum effective length which said resilient means can attain, said sub-assembly being engageable with said inlet valve to close said inlet valve when the effective length of said unit attains a predetermined extended value, further extension of said unit beyond the said extended value being opposed by said resilient means after collapse of said sub-assembly.
Claim 3
Dependent Claim
34 words
An hydro-pneumatic suspension unit as claimed in claim 1, wherein said inlet valve is normally open and is closed by said resilient means when the effective length of the unit attains a predetermined value.
Claim 4
Dependent Claim
140 words
An hydro-pneumatic suspension unit as claimed in claim 1, wherein said resilient means comprises a compression spring acting to urge said piston in a direction opposite to that in which said piston is adapted to be urged by liquid under pressure, at least through a limited range, and said sub-assembly with which said spring is combined is of telescopic construction and surrounds said piston-rod, one end of said sub-assembly acting on the face of said piston adjacent to said closure for the said one end of said cylinder, and the other end of said sub-assembly being adapted to act on said closure when the effective length of the unit attains said predetermined value, further movement of said piston towards said closure in the same direction being operative to contract said sub-assembly and compress said spring to close the inlet valve.
Claim 5
Dependent Claim
37 words
An hydro-pneumatic suspension unit as claimed in claim 1, wherein said sub-assembly comprises first and second telescopic sleeves and radial flanges at adjacent ends of said sleeves are adapted to abut when said sub-assembly is fully extended.
Claim 6
Dependent Claim
37 words
An hydro-pneumatic suspensioN unit as claimed in claim 1, wherein said sub-assembly comprises at least three telescopic sleeves and radial flanges at adjacent ends of said sleeves are adapted to abut when said sub-assembly is fully extended.
Claim 7
Dependent Claim
95 words
An hydro-pneumatic suspension unit as claimed in claim 1, wherein said inlet valve is of the needle type comprising a valve member working in a blind bore in said closure and engageable at its outer end with a seating adjacent to the inner end of said bore which defines said inlet for connection to said source of high pressure liquid the inner end of said valve member projecting into said cylinder and acted on by the end of said sub-assembly remote from said piston when the effective length of the unit attains said predetermined value.
Claim 8
Dependent Claim
23 words
An hydro-pneumatic suspension unit as claimed in claim 6, including an annular stop plate through which said sub-assembly acts on said valve member.
Claim 9
Dependent Claim
51 words
An hydro-pneumatic suspension unit as claimed in claim 1, wherein said piston rod works through a single seal in said closure for the said one end of the cylinder, and said seal comprises the only seal in the unit adapted to be exposed to the pressure of liquid from the source.
Claim 10
Dependent Claim
16 words
An hydro-pneumatic suspension unit as claimed in claim 8, wherein said seal is constructed from P.T.F.E.
Claim 11
Dependent Claim
106 words
An hydro-pneumatic suspension unit as claimed in claim 8, wherein said piston rod is provided with a radial port in communication with one end of an axial bore in said rod of which the opposite end communicates with a complementary axial bore passing through said piston, said port being normally positioned to the high pressure side of said seal but, when the unit is extended below the predetermined value and said inlet valve is closed, said port is disposed on the opposite low pressure side of said seal to exhaust the high pressure liquid from the unit thereby restoring the effective length to the predetermined value.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |