DE2757232A1 - GAS SPRING - Google Patents

Description

IAO Industrie Riunite S.p.A., Beinasco? 0.11.1977 67O4O-A / 77

Gas spring

The invention relates to a gas spring consisting of a tubular metal housing in which a piston is slidably mounted and connected to a rod is, which is sealingly guided and protrudes on one side of the housing therefrom, and the housing on its other end is limited by a bottom, which with pressure-tight closure elements to enclose of the pressurized gas in the housing and a method of manufacturing this gas spring.

Gas springs comprise a tubular metal housing, in which a piston is slidably mounted on a rod which is passed through a piston located at one end of the housing Seal protrudes and in which the housing is limited at its other end by a bottom, which is provided with pressure-tight closure elements to the gas below To keep pressure in the housing.

In the case of conventional gas springs of this type, sealing takes place of the bottom usually by welding. The welding must either be carried out under pressure or an additional valve must be provided to attack the gas spring. In addition to this effort prepares there are also considerable difficulties in producing such a weld seam in an absolutely gas-tight manner.

The object of the present invention is to create a gas spring which can be produced more economically than the known gas springs and which welding operations should not be necessary.

809828/0607

IAO Industrie Riunite S.p.A., Beinasco 11/30/1977 67O4O-A / 77

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According to the invention, this object is achieved in that the pressure-tight closure elements are secured by a plug made of elastomerera material, which is incorporated into the Cylinder housing inserted and eats from a first section in the form of a cup-shaped seal with a the piston facing sealing lip and is in elastic engagement with the inner surface of the cylinder housing is located and has such a shape that it over a certain length with the inner surface of the Cylinder housing is engaged such that the plug is positioned coaxially, and that the bottom from an end portion of the tubular cylinder housing is formed, which is tapered by plastic deformation so that there is a concave annular shoulder for receiving the plug in the cylinder housing and the second section of the plug forms an end section which engages the annular shoulder and which engages the concave shape of the shoulder Has a corresponding convex shape.

In the gas spring according to the invention, the tightness of the seal when it is under pressure with the Gas is filled, achieved by the cup blower Seal or the first portion of the plug engages the inner surface of the tubular housing and above all in that the annular shoulder engages the corresponding end of the plug while additional measures such as welding are not required to seal the floor gas-tight.

According to a preferred embodiment of the invention the gas spring is characterized by the fact that the ring-shaped shoulder delimits the passage to

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IAO Industrie Riunite S.p.A., Beinasco 11/30/1977 670-IO -Λ / 77

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directing the pressurized gas charge into the cylinder housing and forming the second section of the plug has one or more passages which extend from the periphery of the end section towards which the sealing lip extending load bearing first section.

This embodiment of the gas spring is advantageous because it has an inlet for infesting the gas spring has, which by the aforementioned plastic deformation of the end portion of the tubular housing is created. It is no longer necessary to connect the inlet with a ball valve or the like to provide.

The structure and manufacturing method of the gas spring according to the invention are described below with reference to FIG attached drawing based on an exemplary embodiment described. Show in the drawing

Figures 1-7 shortened longitudinal sections showing the successive Phases for manufacturing a gas spring according to an embodiment of the invention illustrate;

FIGS. 8 and 9 are schematic views in elevation - shortened and partially divided into sections - showing the gas spring in the last two manufacturing phases represent;

Figures 10 and 11 are two abbreviated diagrams, around 90 Staggered views of the same gas spring in the finished state;

809828/0607

IAO Industrie Hiunite SpA, Beinasco JO.11.1977 67O4O-A / 77

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FIG. 12 shows a partially schematic section, a variant of the gas spring and its manufacturing process;

Figures 1J and 14 are respectively elevational and elevational views Longitudinal section in an enlarged hatchet of a preferred embodiment of the sealing plug forming part of the gas spring shown in the preceding figures.

You start manufacturing the gas spring according to the invention so that a section of a predetermined length corresponding to the cylinder housing 10 of a metal cylinder is cut off (see Figure 1). At one end of this cylinder section there is an outer annular step formed, with a flattened lower band 12, the purpose of which will be explained below.

In a subsequent phase (Figure 2), the end of the cylinder housing 10, which is opposite the edge 12, subjected to a radial plastic deformation, which is preferably carried out by drawing, so as to be tubular Element to be obtained, which consists of a main section 14, which is the original diameter of the above Has cylindrical portion, an end portion 16 with a reduced diameter and a conical portion -18 for connecting the main section 14 to the end section 16 has. The edge 20 of the end portion 16 is given plastic deformation as a result of the aforementioned plastic deformation a funnel-shaped expanded shape.

The method preferably continues with a phase in which a tubular component 22 (FIG. 3) is inserted into the

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IAO Industrie Hiunite S.p.A., Beinasco 30. ^. 1977 67OAO-A / 77

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End portion 16 is introduced. The outer diameter of the tubular component is dimensioned so that a slight clamping connection is created with the end portion 16, which from the transition from the end section 16 to the conical section 18 up to a certain distance to the Band 20 located location extends.

The method continues - "as shown in FIG. 4 - with a process of bilateral plastic deformation of the conical section 18 and the end section 16 and of the tubular component 22.

This plastic deformation takes place * preferably by means of two jaws acting in the direction of the arrows F. on In this way, a concave bottom 24 is formed at the end of the main portion 14 opposite the band 12, which as

Follow the deformation of the conical portion 18 a

has a shape similar to a spherical section. In addition, the end section 16 is the one shown in FIG Awarded a bell shape. About bottom 24 and the bell-shaped End portion 16 are thus of a diametrical neck, in a passage 28 is retained, connected to one another.

In the main section of the cylinder housing 10 (FIG. 5) designed as described above, then - on its not deformed, correspondie with the bath 12 end - first a plug made of elastomeric material and then a piston 32 of conventional design with one with it connected piston rod inserted. Thereafter, at the end of the corresponding to the flattened band 12 Cylinder housing 10 an annular, the shape of a Bearing bush 36 having bottom, which is an annular having lip-like seal 38 inserted.

809828/0607

ΙΛΟ Industrie Riunite S.ρ.Α., Beinasco JO.11.1977

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The structure of the plug 30 made of elastomeric material will be described later with particular reference to Figs.

After the operation shown in FIG. 5, the flattened edge 12 is flanged inwardly, as shown in FIG. 6, in order to hold the bearing bushing 6 and the seal 38 in place. Furthermore, the wall of the main section 14 "adjacent to the seal 38" is radially plastically deformed and a stop 40 is formed which prevents the piston 32 from reinsing the seal 38.

In the following, FIGS. 13 and 14 as well as reference is made to FIGS. 5 to 7. The plug 30 comprises a first portion 42 in the form of a cup-shaped Seal with a sealing lip 44 · Furthermore, the plug 30 comprises a second section 46 a substantially cylindrical outer shell with a diameter equal to the diameter of the main section 14 of the cylinder housing 10 corresponds.

The section 46 is followed by the section 42 opposite End an end portion 48 of convex shape, which corresponds to that of a spherical cap.

In the outer surface of the second section 46 of the plug 30, recesses designated by 50 are arranged, preferably four in number. These recesses extend over the entire length of the second section 46 and end in the transition zone between the second section 46 and the first section 42 », so to speak, directly below the deformed wall which forms the sealing lip 44.

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Finally, the plug JO has one on its end of the The bottom of the cup-shaped design is limited in the middle Hub 52, which protrudes axially beyond the sealing lip 44 and serves as a bumper for the piston 32.

The plug is thus inserted into the main section 14 of the

Cylinder housing 10 inserted so that the lip 44 and the hub 52 are rotated in the direction of the piston 32. The diameter of the cylindrical portion 46 is like this dimensioned that a sufficiently precise fit with the

Inner surface of the main portion 14 is given. Of the

convex end portion 48 of the plug 30 sits on the concave bottom 24. As can be seen, the convex design of the end section 48 is such that that they essentially correspond to the internal design of the Soil 24 corresponds to a good system of the To ensure plugs at the bottom 24.

When the plug 30 is inserted into the main section I4 of the cylinder housing 10, the second section secures of the plug 30 in that it has a certain length engages the inner surface of the cylinder housing 10, the coaxial positioning of the plug 30 in the The cylinder housing and thereby the first section with its sealing lip 44 becomes coaxial in the cylinder housing 10 held. The diameter of the first section 42 is - in accordance with the sealing lip 44 - greater than the inner diameter of the main portion I4 of the cylinder housing 10, wherein when the plug 30 is in the latter is inserted, the wall of the section 42 is elastically narrowed and the sealing lip 44 in elastic engagement with the inner wall of the cylinder housing 10 stands.

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IAO Industrie Itiuniie S.p.A., Beinasco 11/30/1977 67ΟΛΟ-Α / 77

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When the plug 30 is attached, the recesses delimit 50 with 54 designated passages, which establish a connection between the one filling opening forming constriction 26 past the bell-shaped end portion 16 with the area that is directly behind or below the sealing lip arranged on section 42 44 is located.

Reference is now made to FIG. The bottom or area of the transition 24 of the cylinder housing 10 is arranged on a fixed axial bearing A and at the free end of the rod 34 is a movable pressure element P arranged, which exerts an axial pressure S and so causes the displacement of the rod 34 and the Piston 32 at the end of its stroke against the hub 52 of the Stopper 32 moved.

Under the conditions described above, a gas nozzle U is inserted into the connector formed by the bell-shaped end portion 16 which is connected through a valve to a gas source, normally pressurized nitrogen. When the valve opens, pressurized gas enters passage 28. The plug J> 0 lifts off slightly and the gas flows through the gap created between the convex end section 48 and the base 24 and reaches the passages 54.From there, the gas flows over the sealing lip 44 into the interior of the main section 14. This is possible due to the deformability of the sealing lip 44 formed on section 42.

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IAO Industrie fiiunite S.p.A., Beinasco} 0.11.1977 67O / JO-A / 77

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Said gas initially flows onto the opposite surface of the piston 32 from the rod 34, this causes one strong pressure on the piston, which acts in a direction opposite to the arrows. In this Phase prevents the pressure element P an outward movement of the rod 34 * Besides it holds the Plug in its correct position against the floor or annular shoulder 24. The gas then passes over the piston 32 both the usual between piston and the Inside wall of the cylinder housing 10 existing clearance as well as the usual calibrated openings 56 in the piston self.

After a few seconds, the pressure in the main section 14 of the cylinder housing 10 is between the two seals 38 and 44 the required amount of gas (usually in the range of 90-100 atmospheres) achieved; the gas supplying gas nozzle U closes and is pulled out of the end section 16. Due to the design of the cup-shaped seal 42, the gas does not escape and does nothing more than the sealing lip 44 in engagement with the surrounding wall and the convex end portion 48 with the bottom 24 into engagement bring.

After the filling carried out in the manner described above, the device is removed from the attachment, .which the bearing A and the pressure member P is removed, and the end portion 16 and the neck 26 are subjected to plastic deformation by crushing preferably between two flat plates of a punch press · This deformation is in the same, by

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IAO Industrie Riunite S.p.A., Beinasco 11/30/1977 67O4O-A / 77

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The direction shown by arrow G in FIG. 8 causes the above-mentioned deformation (arrow P, FIG. 4).

By said squeezing, a flattened end portion is formed in the cylinder housing 10, which with 58 and is reinforced by the tubular member 22, which is itself flattened.

The flattened end portion 58 is ultimately in the FIGS. 9, 10 and 11 are cut off so that an ear 60 with a hole 62 is produced. That with a perforated ear 60 forms an attachment to one end of the gas spring.

As shown in FIGS. 10 and 11, a tail part is made in the usual manner at the free end of the rod attached, which forms a fastening part of the gas spring and also has an ear 66 provided with a hole.

The tubular reinforcing element 22, which in flattened State remains in the fastening part 60, only has the function, the latter a required one To give strength which is greater than twice the strength of the cylinder housing 10. In certain use cases this reinforcement may not be necessary.

FIG. 12 shows part of another embodiment of the gas spring according to the invention. This variant is achieved by starting from a pipe section made of metal, as it is denoted by 10 in FIG. An end this pipe section is punched, swaged or

809828/0607

IAO Industrie Riunite S.p.A., Beinasco 11/30/1977 67O4O-A / 77

the like subjected to radial plastic deformation to form a tubular element 110 having a shape as shown in FIG the main section I4 shown in Figures 6 and 7 completely Similar main section II4 and with a base delimiting an annular shoulder 124. That shoulder 124 has the shape of a spherical cup with a circular central opening or central passage 128.

Before a plug 30 is inserted into the tubular element 110, which with the already described and is identical or shown in Figures I3 and I4 but similar to it, a screw 160 with a profiled head 162 is inserted into this element 110. The one with Threaded shank 164 of screw I60 is inserted into the Passage 128 is inserted so that it extends axially out of the corresponding end of the housing or tubular member 110 protrudes in order to thus close a fastening element provided instead of the ear 60 according to FIGS. 8 and 10 form. Between the head 162 and the shaft I64 of the Screw I60 is an annular groove I66, which play or a connecting passage between the Inside and outside of the annular bottom or shoulder 124 is intended to provide.

The plug 30 is inserted into the housing 110 · followed by the piston 32 and its rod 34t as * - ^{n is} the phase of the procedure with reference to Figure 5. The method then continues in the manner described with reference to FIGS. 6 and 7, but with the difference that the bearing A according to FIG. 7 is replaced by a bearing mounting AS. This has a seat SD,

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IAO Industrie Riunite S.p.A., Beinasco 30.11.1977 67O4O-A / 77

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which is capable of accurately receiving the bottom 124 and the part adjacent to the main section 114 and a vulstförnige seal OR, which the shaft I64 of the Accepts screw I60 with tolerance, provides gas pressure tightness between the seat SS and the main section 114.

The seat SS stands over a channel CS with a connector B in connection, which, like the gas nozzle U according to FIG. 7f, can be connected to a gas source under bridge is.

While, as in the Pail of FIG. 71 & FIG. 7, axial pressure is exerted on the rod 134, which at the end of its stroke holds the piston 32 against the plug J> 0 and the latter against the base or shoulder 124, the insertion of the head 162 of the screw I6O is established between the channel CS and the source of pressurized gas, and the gas flows into the interior of the main section 114 and takes the path dictated by the tolerances around the shaft I64, the rod 128 and the passages 54 is formed, and flows further over the eye lip 44

Bas charging the gas spring then continues in the previously described way. When it is terminated, the connection between the channel CS and the gas source is interrupted and the gas spring is removed from the bearing mounting AS.

You manufacture the gas spring is completed in this way because of the internal pressure of the spring pushes the screw holds in the correct position in plug 30; the shaft the screw forms one of the fastening elements of the gas spring.

809828/0607

IAO Industrie Hiunite S.p.A., Beinasoo 11/30/1977 67O4O-A / 77

According to a further embodiment of the invention, the gas spring according to the invention can with a bottom and a fastener as shown in Figures 9-11 or Figure 12, but with a plug, which has the general shape of the 3 ° plug, but not with grooves or other types of passages are provided.

In this case, the spring can be charged with pressurized gas in a conventional manner, e.g. by placing the housing and the other components of the gas spring - before the locking elements on the side the outward movement of the rod to be sealed - be placed in a chamber, then pressurized gas is passed into the chamber and the above-mentioned sealing of the closure elements takes place against escape of gas under pressure.

This makes possible a solution, albeit a less advantageous one however, it achieves a saving over the prior art because it is through the use a plug is no longer required, one Hermetically sealing the passage at the bottom through Make welding.

As can be seen, a gas spring according to the invention are produced in the process according to the invention, wherein all fastening work is considerably simplified compared to conventional methods, whereby a high degree of automation is made possible. The most outstanding property of the gas spring and its manufacturing process is the fact that the sealing is

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IAO Industrie Riunite S.p.A., Beinasco 11/30/1977 67O4O-A / 77

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the presence of pressurized gas is very economical is effected by means of a simple plug made of elastomeric material without hermetically sealing the Passage through which the gas was initially admitted, e.g. by welding, is necessary.

809828/0607

Claims (15)

ΙΛΟ Industrie Hiur.ite Ξ.p.Α., Beiniaco November 50, 1977 67O4O-A / 77 . 2757-32 Claims 1 _V gas spring, consisting of a tubular metal housing in which a piston is slidably mounted, which is connected to a rod which is sealingly guided and protrudes from the housing on one side, and the housing at its other end from a base is limited, which is equipped with pressure-tight closure elements for enclosing the pressurized gas in the housing, characterized in that the pressure-tight closure elements are formed by a plug (jO) made of elastomeric material which is inserted into the cylinder housing (10,110) is inserted and which consists of a first section (42) in the form of a cup-shaped sighting with a sealing lip (44) facing the piston (32) and is in elastic engagement with the inner surface of the cylinder housing (10,110) and has a shape such that it engages over a certain length with the inner surface of the cylinder housing in such a way that the plug (30) is positioned coaxially, and that the bottom is formed by an end portion of the tubular cylinder housing, which is tapered by plastic deformation such that it forms a concave annular shoulder (24,124) for receiving the plug (30) in the cylinder housing (10,110) and the The second portion (46) of the plug (30) has an end portion (48) which engages with the annular shoulder (24,124) and which has a convex shape corresponding to the concave shape of the shoulder (124). 2. Gas spring according to claim 1, characterized in that the annular shoulder (24,124) the limitation of the passage (28,128) for introduction ORIQiNAL INSPECTED 809828/0607 ΙΛΟ Indiuitrie.Riur.itc S.ρ.Α., Bein.-.no 11/30/19 ⁷ Y 67Ο4Ο-Λ / 77 the pressurized gas charge in the cylinder housing (1O, 11O) and the second section (46) of the plug (30) has one or more passages (54) extending from the periphery of the end portion (40) to the first bearing the sealing lip (-14) Section (42) extend so that the gas in the space Piston (J2) can reach. 3. Gas spring according to claim 1 or 2, characterized in that the ear (60) of the cylinder housing (1O) is flattened by squeezing and over
a tapered transition (24) with the not
deformed main section (I4) of the cylinder housing
(1O) is connected, the transition (24) forming the annular bottom or the annular shoulder, which (r) the plug (30) in the cylinder housing supported, un d that the flattened part (ear 60) forms an attachment. 4. Gas spring according to claim 4 »characterized in that in the flattened part (ear 60) de3 cylinder housing a tubular reinforcing
Component (22) is inserted, which is also through
Squeezing is flattened. 5. Gas spring according to claims 3 or 4i, characterized in that the flattened part the cylinder housing has the shape of an ear provided with a hole. 6. Gas spring according to claim 1 or 2, characterized in that a connection is formed by a screw (160) with a head (I62), 809828/0607 IAO Industrie Riunite S.p.A., Boinasco 11/30/1977 67Ο4Ο-Λ / 77 which between the plug ($ 0) and the ring-shaped Shoulder (124) arranged and threaded with a provided shaft (164) is provided axially extends outwardly with clearance through a central passage (128) which extends from the annular shoulder (124) is limited. 7 · Gas spring according to claim 2, characterized in that that the passage or each passage is formed by an elongated recess (50) which on the peripheral surface of the second portion (46) of the plug (30) is provided and which extends from the the second section (46) and the first section (42). 8. Gas spring according to claims 1,2 or 7t, characterized in that on the end side of the plug (30), defined by the bottom of the plate-like shape of the first section (42), a central one Have (52) is provided, which extends axially over the sealing lip (44) »the one stop for the piston (32) forms, extends beyond. 9. A method for producing a gas spring according to any one of claims 2-5 and 7 and 8, characterized in that that the process comprises the following phases - A section of a metal tube (10, Figure 1) is provided which is intended to form the tubular housing (10, Figure 1) of the spring. 809828 / 06D? IAO Industrie Uiunite Cp.A., Beinano 11/30/1977 67O4O-A / 77 - An end section of the tube is subjected to a radial plastic preforming, so that a Pipe section with a main section (I4) »which has the original cross-section of the pipe section, and having an end portion formed by the end portion (16, Figure 2) with a reduced diameter and with a conical section (18) which connects the main section (Ή) and the end section (16) with one another join, made wix'd. - The section (18) and the end section (16, Figure 2) undergo bilateral plastic deformation (f) subjected in such a way that a diametrical constriction (26) is formed and that with the connecting portion the aforementioned transition section or floor (24) at the corresponding end of the main section (14) is formed and the end portion is given a cup-like shape (16, Figure 4), with a passage (28) remains between these two sections. - In the main section (14) it is not deformed by its End the above-mentioned plug first (30) inserted from elastomeric material, in such a way that its section (42) faces this end. Then, the plunger (3 ²⁾ is inserted with its rod (34) and is fastened a bearing bush (36) for guiding the rod (34) i ⁿ or at the non-deformed end, and around the rod (34) · - An axial pressure (s) is exerted by the free end of the rod (34) in such a way that the plug (30) is moved and held essentially against the transition or floor (24). 809828/0607 IAO Industrie Hiunite S.p.A., Beinasco 11/30/1977 67O4O-A / 77 - A gas nozzle (U) connected to a source under pressure Standing gas can be connected, is introduced gas-tight into the cup-shaped end portion (16, Figure 7). - The gas nozzle (U) is connected to the gas source, while the plug (30) against the corresponding Bottom (24) is held so that pressurized gas into the interior of the main section (14) is admitted, the influx of gas in this space thanks to the absence of any Sighting between the latter and the second section (46) of the plug and thanks to the elastic constriction of the first section (42) takes place. - The connection between the gas nozzle (u) and the source is interrupted and the gas nozzle (u) is removed from the end section (16, Figure 7) and - The end section (16, Figure 7) and the constriction (26) are subjected to plastic deformation by crushing such that an above-mentioned flattened end part (58) is produced, the deformation of which is effected in the same direction (G) as that bilateral deformation mentioned above. 10.Verfahren according to claim 9 »characterized in that the radial plastic deformation takes place by pulling. 11. The method according to claim 9 for producing a gas spring according to claim 4 »characterized in that before the lateral plastic deformation a tubular component (22, Figure 3) in the end 809828/0607 IAO Industrie Riunite S.p.A., Beinnsco 11/30/1977 67Ο4Ο-Λ / 77 - 6 - cut (16, Figure 3) with reduced diameter is inserted, which together with this end portion (16) of a gradual plastic deformation is subjected so that a reinforcing element (22, Figures 8 and 9) of the flattened end (ear 60) is formed. 12. The method according to claims 9 or 11, characterized characterized in that the bilateral plastic deformation is effected by punching. 13 · Method according to claims 9 or 11, thereby characterized in that the plastic deformation is effected by crushing by means of "a punch press will. 14 · Method according to one of claims 9 »11 and 12 for Manufacture of a gas spring according to claim 71, characterized in that the flattened End portion (58) is subjected to a cutting process in which the shape of a hole provided Ear (6θ) is achieved. 15. A method for producing a gas spring according to a of claims 2, 7 and 8, characterized in that it comprises the following phases: - A piece of metal pipe (10, Figure 1) is provided from which the tubular housing (110, Figure 12) the spring is to be formed. 809828/0607 IAO Industrie Riunite S.p.A., Beinasco November 30, 1977 67O4O-A / 77 - The end piece of the pipe is subjected to radial plastic deformation to form a tubular Element (110), which is a main section (114) with the original cross-section of the Tube and a bottom having an annular shoulder (124) with a central passage (128) forms. - A screw is inserted into the tubular element (HO) (160) inserted with a head in such a way that the turned shaft (I64) of the screw extends axially through the central passage (128) extends and the head (162) of the screw on the annular shoulder (124) is attached in the tubular element (HO), so that the screw as a fastening of the Oasfeder serves. - From the undeformed end of the main section (II4) First, the plug (30) is made of elastomer in this em material inserted in such a way that the first section (42) faces the undeformed end is. Then the piston (32) is inserted with its rod (34) and an annular element (36) for Passing the rod (34) in or on the undeformed end and around the rod (34) attached, which has appropriate seals. - The deformed end of the tubular element (HO) is inserted into a seat (SD) which is in a Bearing attachment is provided, the seat in the region of the tubular element (114) with seals (OR) and capable of communicating with the source of pressurized gas. 809828/0607 IAO Industrie Hiunite SpA, Beinasco 11/30/1977 67 (V ₁ O-Λ / ?? - An axial pressure (S) is applied from the free end of the rod (34) exerted on the piston (j2) so that the The stopper is moved against the annular shoulder (I24) and held with the head inserted (162) of the screw (160). - The seat (SD) is connected to the gas source, while the plug (30) against the corresponding one Bottom (24) and against the head (I64) of the screw (16O) is held so that a quantity of pressurized gas through a gap (166) between the central passage (128) and the shaft (164) of the Screw (16Ο) is inserted into the interior of the main section (114), with the inflow of the gas takes place in this space because there is no seal between the latter and the second section (46) of the plug is present and due to the elastic contraction of the first section (42). - A connection is inserted between the seat (SD) and the source and the deformed end of the tubular Element (HO) is removed from the seat (SD). 8 09 828/0607