US4372545A — Shock absorber for a vehicle with a flexible susp…

Claim 1

Independent Claim 364 words

A hydraulic shock absorber for a vehicle with a flexible suspension, comprising: a damping piston member slidably mounted in a first cylinder member containing a liquid immersing the damping piston member; at least one return spring bearing simultaneously on said damping piston member and on said first cylinder member to maintain at rest the damping piston member in a predetermined position relative to the first cylinder member to allow the latter to effect a useful travel inside said first cylinder member in each direction; a compensation piston member slidably mounted in a second cylinder member communicating with said first cylinder member and containing said liquid, said compensation piston member being immersed in said liquid, said predetermined position of the damping piston member being independent of the position of the compensation piston member; at least one of said piston members being integral with a sliding rod traversing one end of said cylinder member in which said one piston member is slidably mounted; means for compensating variations of an internal volume defined in said cylinder member resulting from sliding of said sliding rod into and out of said cylinder member; one of said damping piston and first cylinder members being integral with one of said compensation piston member and second cylinder member, whereas, the other of said members are fixed respectively to a suspended part and an unsuspended part of the vehicle; at least one passage extending through said compensation piston member, said passage being controlled by at least one sealing valve sensitive to a relative displacement speed between said parts of the vehicle to open said passage when said relative displacement speed is below a given limiting speed, in order to allow a displacement of said compensation piston member inside said second cylinder member when the load of the vehicle varies, and to seal said passage when said relative displacement speed exceeds said given limiting speed, in order to prevent said compensation piston member from moving inside said second cylinder member when the relative displacement between said parts of the vehicle should be damped, the location of said damping piston member relative to said first cylinder member being independent of the load of the vehicle.

Claim 2

Dependent Claim 364 words

A hydraulic shock absorber for a vehicle with a flexible suspension, comprising: a damping piston member slidably mounted in a first cylinder member containing a liquid immersing the damping piston member; at least one return spring bearing simultaneously on said damping piston member and on said first cylinder member to maintain at rest the damping piston member in a predetermined position relative to the first cylinder member to allow the latter to effect a useful travel inside said first cylinder member in each direction; a compensation piston member slidably mounted in a second cylinder member communicating with said first cylinder member and containing said liquid, said compensation piston member being immersed in said liquid, said predetermined position of the damping piston member being independent of the position of the compensation piston member; at least one of said piston members being integral with a sliding rod traversing one end of said cylinder member in which said one piston member is slidably mounted; means for compensating variations of an internal volume defined in said cylinder member resulting from sliding of said sliding rod into and out of said cylinder member; one of said damping piston and first cylinder members being integral with one of said compensation piston member and second cylinder member, whereas, the other of said members are fixed respectively to a suspended part and an unsuspended part of the vehicle; at least one passage extending through said compensation piston member, said passage being controlled by at least one sealing valve sensitive to a relative displacement speed between said parts of the vehicle to open said passage when said relative displacement speed is below a given limiting speed, in order to allow a displacement of said compensation piston member inside said second cylinder member when the load of the vehicle varies, and to seal said passage when said relative displacement speed exceeds said given limiting speed, in order to prevent said compensation piston member from moving inside said second cylinder member when the relative displacement between said parts of the vehicle should be damped, the location of said damping piston member relative to said first cylinder member being independent of the load of the vehicle.

Claim 3

Dependent Claim 65 words

A hydraulic shock absorber according to claim 1, wherein said first and second cylinder members define coaxial portions of a single cylinder, said damping piston member being integral with a first sliding rod fixed to a first of said parts of the vehicle and said compensation piston member being integral with a second sliding rod fixed to a second of said parts of the vehicle.

Claim 4

Dependent Claim 86 words

A hydraulic shock absorber according to claim 2, wherein said return spring is a helical spring surrounding said single cylinder, one end of said spring bearing on a flange surrounding and fixed to the single cylinder and the other end bearing on a cap fixed to said first sliding rod, said flange and said cap each having a profiled edge forming a threaded groove maintaining the corresponding end of said spring, whereby the latter acts in tension and in compression between said cap and said flange.

Claim 5

Dependent Claim 74 words

A hydraulic shock absorber according to claim 3, wherein a substantially cylindrical protective sleeve is located within the helical return spring coaxially to the first sliding rod and defines a closed end fixed to the latter and applied against said cap and an opening covering the adjacent end of the single cylinder, said protective sleeve being adapted to slide externally on the latter when said first sliding rod moves relative to said single cylinder.

Claim 6

Dependent Claim 101 words

A hydraulic shock absorber according to claim 1, 2, 3, or 4, wherein the compensation piston member comprises two disks through which extend said at least one passage, the latter being radially displaced relative to the second sliding rod, two inner facing faces of said disks being substantially parallel and separated by a gap in which is disposed a flexible blank washer centered on the second sliding rod and having a peripheral edge mounted with a radial clearance relative to said single cylinder, said washer forming said sealing valve sensitive to the relative displacement speed between said parts of the vehicle.

Claim 7

Dependent Claim 41 words

A hydraulic shock absorber according to claim 5, wherein each of said inner facing faces has, in section, a curved profile substantially matching the profile of said washer when the latter is elastically deformed and bears against said inner facing face.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-02-07	1986-08-09	1987-02-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-02-07	1990-08-09	1991-02-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-02-07	1994-08-09	1995-02-08	$7700.00	Window Closed / Lapsed

Shock absorber for a vehicle with a flexible suspension

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