Fichtel & Sachs Ag

Felix Wossner

Ludwig Axthammer

Gunther Handke

Hermann Itzinger

Wolfgang Geiling

Gunther Heyer

Manfred Koller

Wilhelm Koch

Robert Eusemann

Wilhelm Wecker

German Schmitt

Paul Spichala

Karl Kany

Leopold Schopplein

In an electromagnetically operated valve, the armature of a solenoid is arranged in substantial alignment with a valve seat surrounding a channel. The valve seat has a substantially planar surface. A valve member also having a substantially planar surface is provided to sealingly engage the planar surface of the valve seat. The armature of the solenoid has a spherical end face engaging the annular valve member.

Fluid passage unit

According to an illustrative example of the invention, an impact damper comprises two telescopically arranged tubes. Working chambers are defined within the tubes, and a fluid is contained within the tubes. The fluid biases the tubes towards a relative rest position. This rest position is defined by abutments of both tubes. In case of impact, the tubes are moved with respect to each other, and damping fluid is urged through a damping orifice between adjacent working chambers. In case of excessive temperature, the pressure of the fluid within the telescopic tubes is raised so that the pressure of the damping fluid is also raised. This raising pressure may result in a metallic sealing through abutment of the tubes. This metallic sealing may prevent the escape of damping fluid such that the pressure can rise up to a dangerous level. For limiting the pressure rise, an emergency escape passage is provided across the location of abutment.

Impact damping unit

The invention provides a single-tube vibration damper of variable damping force which consists of simple and easily produced components and permits problem-free assembly. This is achieved in that the cylinder comprises an open cylinder end provided with the cylinder diameter and is arranged therewith on the side remote from the piston rod exit in the container. The inflow passages for a damping device externally fitted on the container are formed by an annular space present between cylinder and container and divided by means of seal.

Single-tube vibration damper of variable damping force

For a double-tube vibration damper which comprises an axially proceeding groove in the cylinder for by-passing the piston valves, a piston is provided which possesses a satisfactory sealing and guidance function in the cylinder. This is achieved in that the piston comprises a rigid piston ring arranged in a piston groove and acting as sealing ring against the cylindrical surface, while the piston comprises a second piston ring groove for the reception of a guide ring consisting of a piston ferrule. In this case at least one relief passage is provided which connects the second piston ring groove and/or the space situated between the piston ring grooves with the working chamber remote from the piston rod.

Double-tube vibration damper

In a double-tube vibration damper the piston acts on an abutment spring when arriving at a predetermined position during its inward stroke. The abutment spring acts on a control member. The control member cooperates with a bottom passage to reduce the cross-sectional area of the bottom passage in response to the piston starting to act onto the abutment spring such as to reduce the cross-sectional area of the bottom passage. In this way a hydraulic abutment function is obtained on inward movement of the piston rod. The control member is biased by a return spring towards the abutment spring. The abutment spring acts with its end remote from the control member onto a friction ring, which friction ring is frictionally guided by the inner face of the cylinder. The biasing action of the return spring is larger than the force necessary for moving the friction ring along the inner face of the cylinder.

A vibration damper for vehicles is disclosed with a variable damping force. The vibration damper includes two series-connected damping valve systems which effect a damping force variation by means of a blockable bypass passage. An externally influenceable damping force in at least three stages is obtained in that the bypass passage bridges the two series-connected damping valve systems. This bypass passage has outer passages which open into the chambers separated by the damping valve arrangement and a further intermediate passage which opens to a space between the damping valve systems. At least two passages are closable to change the damping of damping fluid displaced between said chambers.

Vibration damper with variable damping force

A vibration damper for vehicles is disclosed with a variable damping force. The vibration damper includes two series-connected damping valve systems which effect a damping force variation by means of a blockable bypass passage. An externally influenceable damping force in at least three stages is obtained in that the bypass passage bridges the two series-connected damping valve systems. This bypass passage has outer passages which open into the chambers separated by the damping valve arrangement and a further intermediate passage which opens to a space between the damping valve systems. At least two passages are closable to change the damping of damping fluid displaced between the chambers.

In gas springs, shock absorbers and the like, the cylinder member may be provided with an interconnection groove on its internal face. This groove is to interconnect two working chambers on both sides of a piston member movably received within the cylinder member. This interconnection groove is produced by a roller member introduced into the cavity of the cylinder member and having an axis substantially perpendicular to the axis of the cylinder member. The roller member has an annular elevation on its circumferential surface which is to engage the internal face of the cylinder member. A support face profiled according to the profile of the external face of the cylinder member is brought into contact with the external face of the cylinder member. The elevation of the roller member is angularly aligned with a metal receiving groove of the support face. The roller member is hereupon radially pressed against the internal face of the cylinder member and axially moved corresponding to the axial length of the interconnection groove to be obtained. So, the interconnection groove is generated by an embossing action and the metal corresponding to the interconnection groove being obtained is urged to flow into the metal receiving groove.

Method of manufacturing a cylinder member of a cylinder piston unit

In a double-tube vibration damper the working chamber adjacent the piston rod guide member is connected to the compensation chamber surrounding the cylinder through a by-pass valve. The by-pass valve is mounted in the cylinder or in a structural member stationary with respect to the cylinder. The by-pass valve has a cross-sectional area variable in dependency on a pressure signal or an electric signal. The damping characteristics of the vibration damper can be varied e.g. in dependency on the load charged onto the vehicle of which the vibration damper is a part.

A piston rod particularly for shock absorbers and spring devices has been shown in the illustrative embodiments. The piston rod comprises a tubular member which tubular member is provided with at least one extension of reduced diameter. The extension is intended for being fastened to associated structural members. In view of fluid-tightly closing the interior of the piston rods on at least one of their ends, a closure member is provided within the cavity defined by the extension of reduced diameter. The closure member is fastened to the piston rod by the reduction of the diameter of the piston rod.

Method of making piston rod for shock absorbers

The characteristics of a double-tube shock absrober are variable in response to temperature variations as a result of viscosity variations of the damping liquid. In view of compensating for such variations of the damping characteristics the central cavity is connected with the annular compensation chamber by a throttled flow cross-sectional area. This throttled flow cross-sectional area is variable in response to ambient temperature. In view of varying the flow cross-sectional area a control bar is provided on the outer surface of the cylinder of the shock absorber. This control bar extends substantially in axial direction of the shock absorber and is fixed to the cylinder at a location remote from the location of the throttled flow cross-sectional area. The other end of the control bar cooperates with the flow cross-sectional area and effects the variation thereof.

Shock absorber unit with temperature compensation

In a cylinder piston device having an axis and two end walls, a cavity is defined between the two end walls. A piston rod is axially movable with respect to the cylinder member and passes through one of the end walls. The piston rod is at least partially defined by a piston rod tube. A piston unit is defined by a radially widened portion of the piston rod tube. The piston unit separates the cavity into two working chambers adjacent respective end walls, one of the working chambers being an annular working chamber radially extending between a radially outer surface of the piston rod and a radially inner surface of the cylinder member. Fluid passages extend between the working chambers across the piston unit. The fluid passages includes at least one opening extending through the piston rod tube.

Piston rod with an integral piston for a shock absorber

In a pressurized fluid device a cavity is defined within a container. A piston rod passes through a piston rod guide and seal unit of the container. The piston rod guide and seal unit has an axially inner and an axially outer sealing element sealingly engaging the piston rod. The axially inner sealing element acts as a check valve permitting flow of fluid towards the cavity and preventing flow of fluid out of the cavity. An intermediate chamber is defined between the axially inner and the axially outer sealing element around the piston rod. A filling passage is provided across the piston rod guide and sealing unit. This filling passage includes an axially outer filling passage section across the axially outer sealing element between the intermediate chamber and the exterior of the pressurized fluid device.

Pressurized fluid device

A vibration damper including a vibration damper mechanism composed of a piston-and-cylinder construction located within a pipe jacket wherein fitting elements such as a spring retainer and a steering knuckle support are attached on the pipe jacket by a mounting construction in accordance with the invention. The fitting elements are located on the pipe jacket at their corresponding positions and they are deformed in such a way that radially inwardly directed projections of the fitting elements are shaped in conformity with corresponding indentations of the pipe jacket in order to provide a reliable locking connection between the fitting elements and the pipe jacket in a simple and economical manner.

Vibration damper arrangement particularly for a shock absorber strut

A hydropneumatic damping device particularly for spring legs of automotive vehicles comprises an inner cylinder, an outer container, a central cavity within the inner cylinder, an annular cavity between the inner cylinder and the outer container, a piston rod with a piston unit, venting passage means between the central cavity and the annular cavity extending across a cavity-closing unit and check valve means associated to said venting passage means. The check valve means comprises an annular check valve member in frictional sliding engagement with the piston rod for axial movement with the piston rod towards a sealing position during inward movement of the piston rod and towards an opening position during the outward movement of the piston rod. First and second abutment means are provided for defining the sealing and the opening position of the annular check valve member, respectively. The second abutment means are axially fixed with respect to the cavity-closing unit by supporting means separated from the cavity-closing unit and fixed with respect to the respective end of the container.

Growing community of inventors

Schweinfurt, Germany

Felix Wossner