Abstract: A two-wheeled foldable golf trolley is foldable and unfoldable so as to define a transportation and storage condition in the folded status and a use condition in the unfolded status. A gas spring is provided between relatively pivotable parts of the trolley for biasing the trolley towards one of said folded and unfolded position.

Abstract: According to an illustrative example of the invention a cylinder is subdivided by a stationary partition wall into two pressure chambers. A first piston rod is sealingly introduced from atmosphere through one end wall of the cylinder into a first pressure chamber provided on one side of the partition wall. A second piston rod sealingly extends through said partition wall from the first pressure chamber on one side of the partition wall to a second pressure chamber on the other side of the partition wall. A lower gas pressure is provided in the first pressure chamber and a higher gas pressure is provided in the second pressure chamber. Abutment faces are allocated to the first and to the second piston rod. On inward movement of the first piston rod with respect to the cylinder the abutment faces enter into engagement after a predetermined path of inward movement of the first piston rod.

Abstract: In a gas spring the piston rod passes through a guide ring at one end of a container. On the inner side of the guide ring there are provided two sealing rings, a first axially outer sealing ring adjacent to the guide ring and a second axially inner sealing ring spaced from the first sealing ring. A working chamber is defined axially between the second sealing ring and the second end of the container. Pressurized gas is contained within the working chamber. An annular sealing chamber is defined axially between the first and the second sealing ring. Both sealing rings are provided with a respective radially inner sealing lip sealingly engaging the piston rod and a radially outer sealing lip sealingly engaging the container. Respective sealing lips are axially directed towards the sealing chamber. A volume of pressurized gas is contained within the sealing chamber. The pressure within the sealing chamber exceeds the pressure within the working chamber.

Abstract: A positioning device is e.g. used for positioning the door of a motor vehicle in an opened position. The positioning device comprises e.g. a cylinder and a piston rod which extends inward and outwards of the cylinder through one end thereof. A flank face is provided at the inner wall surface of the cylinder. The piston rod carries a piston. The piston is provided with a counter-arresting ring which engages the flank face in a predetermined position. When the piston passes across the arresting flank of the cylinder, the counter-arresting ring is moved radially inwards with respect to the axis of the piston rod against elastic resistence. So, an increased resistance occurs against the axial movement of the piston rod with respect to the cylinder. This increased resistance against axial movement positions the door with respect to the body frame of a motor vehicle in a predetermined opened position and avoids that the door is closed unintentionally.

Abstract: In a telescopic apparatus, an inner telescopic part is axially displaceable in wobble-free manner in an outer telescopic part. For the guidance of the inner telescopic part a carrier sleeve is inserted into the outer telescopic part. The carrier sleeve accommodates at least one guide ring body in universal joint manner. This guide ring body possesses a guide surface section which rests on the outer telescopic part.

Abstract: A positioning device is used for the positioning of a chair seat as to its inclination, or for positioning a back-rest member of a chair. The positioning device is constructed such as usual hydropneumatic springs which can be locked by closing a passage connected to working chambers on both sides of a piston. The working chambers are filled with an operating liquid. In order to adapt the biasing force of such a positioning device, one of the working chambers is conneced with a force-measuring device, which force measuring device is provided within the force transmission path of the respective chair column. The force measuring device comprises a measuring space filled with operating liquid, and this operating liquid is in liquid connection with one of the working chambers.

Abstract: In a friction damper a core part is telescopically movable in an outer part. A friction piston is secured to the core part. The friction piston is pot-shaped and includes a basic body and skirt segments. The skirt segments are integral with the basic body and are held by a spring system in frictional contact with the inner surface of the outer part.

Abstract: In a hydraulic positioning device a piston divides the cavity within a cylinder into two working chambers. The piston is connected with a piston rod passing through one end of the device and with a volume compensating rod through the other end of the device. The piston rod is provided with a passage which can be opened and closed by a valve so as to allow optional adjustment and blocking of the piston rod. The hydraulic liquid within the working chambers is subjected to volume variation in response to varying temperatures. With the aim of compensating such volume variations a partition at one end of the cylinder is supported by an abutment of the cylinder through an axially deformable compensating body having preferably a deformation force--deformation path characteristic which is responsive to temperature.

Abstract: A hydropneumatic spring usable as steplessly blockable setting device comprises a by-pass connection in its piston. In this by-pass connection there is arranged a shut-off valve actuatable from the exterior. Furthermore the by-pass connection can be opened by excess pressure in each of the two working chambers. In this way the setting of length of the hydropneumatic spring can be altered by predetermined inward and/or outward thrust forces even when the shut-off valve is closed.

Abstract: In the illustrative embodiment of the invention as described an engine bonnet is articulated to the framework of a motor car. A gas spring is articulated to both the framework and the bonnet. The gas spring balances part of the weight of the bonnet when the bonnet is to be opened by hand. In case of an accident the framework and/or the bonnet may be crushed in longitudinal direction of the car. In such case the piston rod of the gas spring is pushed inward of the cylinder beyond the normal innermost operational position and a retaining device becomes effective so as to prevent the piston rod from returning towards its outermost operational position.

Abstract: A continuously adjustable levelling column for chairs comprises a guide tube having a lower end and an upper end. A telescopic tube is guided within the guide tube and has a tapered upper end portion extending beyond the upper end of the guide tube. A gas spring is accommodated within the telescopic tube. This gas spring is axially fixed within the telescopic tube. The upper end of a container of the gas spring abuts through a distance piece a support face at the upper end of the tapered portion of the telescopic tube. A piston rod passing through the lower end of the gas spring is axially fixed with respect to the lower end of the guide tube. A locking control pin extends through the upper end of the gas spring and is engageable through a transmission pin by a control handle.

Abstract: In a fluid-operated device such as a gas spring a piston rod is axially movably guided through a passage in an end wall of the gas spring. A sealing disc of elastomeric material is axially compressed between two supporting faces and engages the piston rod with a convex radially inner edge. The apex of the edge is substantially midway of the axial thickness of the sealing disc. Preferably the sealing disc has also a radially outwardly convex sealing edge which is in sealing engagement with a stationary face surrounding the sealing disc.

Abstract: In a steplessly adjustable hydropneumatic device the spring chamber of which is arranged at the piston rod exit end and which works with a liquid locking, a very simple hydraulic locking is obtained even for high traction stressing upon the piston rod in that both an annular separator piston and the partition are arranged in the inner chamber of the container, which is penetrated by the piston rod. For the hydraulic traction locking in the case of traction forces exerted suddenly upon the piston rod a valve device is provided which cooperates with the piston rod.

Abstract: In an arrangement of gas springs as weight counter-balance and retaining device for a part pivotable substantially about a horizontal axis such as a flap, lid or door, a simple construction is required which guarantees two stable open positions for the pivotable part. This is guaranteed in that two gas springs are arranged where the first of the two gas springs possesses an outward thrust force acting over the entire range of displacement of the pivotable part, while the second gas spring possesses an outward thrust force acting over a part of the displacement range and an additional force-free displacement range.

Abstract: A taper connection between a chair column and a seat plate is proposed. The external taper of the chair column adjoins a cylindrical section of the chair column. The internal taper of the seat plate, fitted together with the external taper of the chair column, protrudes beyond the transition between cylindrical section and external taper.

Abstract: For a temperature-compensated gas spring, which consists of a container in which a concentrically arranged cylinder is arranged, where a main pressure chamber is separated in sealing manner from an auxiliary pressure chamber by a piston which is connected with a piston rod, a damping arrangement is provided for controlling the outward thrust speed. This is effected in that a damping chamber is arranged in which a damping piston provided with damping valves slides, the damping piston being arranged on an auxiliary piston rod which is in axially fixed connection with the piston rod.

Abstract: Gas springs are frequently used for assisting the movement of a movable construction unit, e.g. a boot lid with respect to a stationary construction unit, e.g. a motor car frame. In view of facilitating the closing operation of the boot lid, the pressure in the gas spring is sometimes selected such that the gas spring cannot fully overcome the gravitational forces acting onto the boot lid. In such cases the gas spring cannot fulfill the function of maintaining the boot lid in the upper terminal, i.e. the fully opened position without additional provision. In order to enable the gas spring to maintain the boot lid in the upper terminal position, the gas spring is constructed such that in the outer terminal position of the piston rod with respect to the cylinder an increased resistance is exerted by the gas spring against pushing the piston rod inwards of the cylinder. A simple and economic hydraulic circuit is proposed in view of achieving such increased resistance.

Abstract: In a pneumatic or hydropneumatic tension spring which consists of a container in which a cylinder is concentrically arranged and a liquid and/or gas filling under pressure has an inward force upon a piston rod, between a working chamber on the piston rod side and an annular chamber a damper device is arranged which generates a greater damping effect in the inward movement of the piston rod than in the outward movement of the piston rod. Due to this measure a damped inward movement of the piston rod is achieved while the extraction of the piston rod can be effected without appreciable damping.

Abstract: A gas spring particularly for jumping stilts comprises a working cylinder and a plunger. In the working cylinder there is a working chamber containing a mass of gas. A gas exchange chamber is fixed with respect to the working cylinder. An exchange passage connects the working chamber and the gas exchange chamber. A gas exchange valve is provided in the exchange passage. An exchange operating handle is provided separate from the plunger.

Abstract: In a cylinder piston device two working chambers on both sides of a piston are interconnected by a fluid passage. This fluid passage includes in series a first passage section and a second passage section. The first passage section comprises a first bore and a second bore in parallel. The first bore is always open. The second bore is opened and closed by a throttling valve body in response to the direction of axial movement of the piston. The second passage section is opened or closed selectively by a closure body controlled from outside the cylinder.