Abstract:
The present invention relates to a spring damper system for bicycles having a first load-applying segment, a second load-applying segment, at least one spring mechanism, a damping means, and a regulating mechanism that automatically effects a damping behavior of the damping means based on a tension or load present in the at least one spring mechanism. A method of spring suspension and damping of bicycles is also provided.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a spring damper system for bicycles as well as a method of spring suspension and damping of bicycles. 
   Apart from spring damper systems mounted on bicycle handlebars or bicycle seats, there are in particular known spring damper systems for bicycles which serve the wheel bearing. 
   Spring damper systems utilized for the suspension of bicycle wheels are known from configurations which are effective between a bicycle&#39;s front wheel and its frame as well as from configurations which are effective between a bicycle&#39;s rear wheel and its frame. 
   Spring damper systems which are effective between a bicycle&#39;s front wheel and its frame are known from configurations in which the spring damper system is arranged in a region of the fork tube as well as from configurations in which the spring damper system is arranged in the region of the bicycle fork. 
   As a rule, spring damper systems arranged in the region of the bicycle fork are integrated into one or both stem tubes, fork tubes respectively. 
   Spring damper systems for a bicycle&#39;s rear wheel suspension as such have become known in which, based on an oil-damping principle, a damping cartridge is externally surrounded radially by a steel spring. There are other isolated spring damper systems already known which employ gas springs. Also known are systems utilizing a gas spring acting as a positive spring as well as a gas spring acting as a negative spring. 
   SUMMARY OF THE INVENTION 
   It is the task of the present invention to provide a further spring damper system. 
   In accordance with a special aspect, the invention is based on the task of providing a spring damper system which can readily be adapted to different operational conditions. 
   In accordance with a special aspect, the invention is based on the task of providing a spring damper system for vehicles such as bicycles which is operationally reliable given different road surfaces and different cyclists and which exhibits comfortable spring damping properties and, in addition, does away with the need for excessive assembly or adjusting efforts to the greatest degree possible. 
   This task is solved by a spring damper system in accordance with claim  1 . 
   Preferred configurations of the invention comprise the subject matter of the subclaims. 
   It must first be pointed out that the inventive spring damper system as well as the inventive procedure can in principle be utilized in a wide variety of applications, for instance in various vehicles and the like. For purposes of simplification, however, an example of the invention will be described within the context of this disclosure as a spring damper system and/or method used or for use in damping/suspension of a bicycle wheel and particularly with respect to a bicycle&#39;s rear wheel damping/suspension. The given indication of “for bicycles,” however, is not to be construed as a limitation of the protective scope but rather merely refers to a preferred feasible application. 
   In accordance with the present invention, a spring damper system is provided to particularly comprise a spring mechanism and a damping means whereby the damping behavior of said damping means is adjusted automatically with a regulating mechanism. In accordance with the invention, this automatic adjusting is effected in relation to the tension which is given, particularly at that current moment, in a spring of the spring mechanism. 
   Said spring is preferably a gas spring or preferably comprises a gas spring. 
   The spring mechanism as well as the damping means are respectively arranged to be operatively effective between a first and a second load-applying segment of the spring damper system. 
   It is preferable to provide for the spring mechanism as well as the damping means to also be respectively arranged spatially between the first and the second load-applying segment of the spring damper system. 
   The term “damping behavior” with respect to the damping means of the present invention is to be understood in a broad sense. “Damping behavior” is especially to be understood as the damping rate of said damping means. 
   The “damping behavior” of the damping means may, however, also be, for example, the force which is actually exerted on the damping means, effectively damped respectively. Thus, as an example, it is also preferred that contingent upon the force/tension given in the spring mechanism, the regulating mechanism determines a force or force component to be introduced to the damping means. 
   It particularly preferential for the damping rate of said damping means to be set for a pre-defined section of the damping means&#39; load versus displacement characteristic. It is also preferred that the damping rate be set for the entire load versus displacement characteristic of the damping means. 
   The adjusting or modifying of the damping rate preferably transpires in finite steps or in infinitely variable fashion or according to a pre-defined function or in some other way. 
   The damping behavior is preferably set such that modification of the damping means is effected at one or several respective displacement positions and/or load values of the load versus displacement characteristic and this notably being especially automatically, contingent upon the force being exerted on the damper. 
   In preferred configuration, the automatic adjusting is effected such that the damping rate is always constant with respect to pre-defined displacement and/or load intervals and changes upon transition into one or several adjacent intervals. 
   The transitional zones between such intervals may be of different configurations such that, for example, the damping rate increases substantially sharply between said intervals or such that the damping rate leads from one to the next in fluent or steady manner. 
   It is moreover preferred that the damping rate changes continuously with respect to the displacement/load across the load versus displacement characteristic. 
   It must be noted that in the sense of the present invention, the load-applying segments are, in particular, areas of the spring damper system which can be coupled with conversion elements such that the spring damper system is effectively operative between two or more of the conversion elements. 
   Such load-applying segments may be, for example, housing segments, which are arranged to be movable relative one another such as, for instance, the respective terminating ends of different cylindrical housing segments arranged to be displaceable relative to one another in the axial direction. The load-applying segments may be, for example, configured in eyelet or grommet fashion; in particular, the load-applying segments are configured so as to accommodate mounting means such as, for example, a screw or a pin or the like. It is, however, noted that a load-applying segment may also be of different configurations and a plurality of other further configuration are likewise preferred. 
   The load-applying segments of an inventive spring damper system may all be configured the same or differ from one another. 
   The spring mechanism preferably comprises at least one spring configured as a gas spring, whereby the adjusting of the damping behavior/damping rate of the damping means is automatically effected in relation to the tension/load present in same. 
   In preferred configuration, the damping means comprises a system of chambers filled with a damper fluid such as, for instance, oil. This system of chambers may comprise a first and a second chamber between which a damper fluid is moved through damping openings for the purpose of damping. The damping openings connect the two chambers in at least one direction of load. 
   Means are preferably provided that can change the cross-sectional area rendered opened with respect to the damping openings. 
   It is particularly preferred to provide for valve means to clear the different directional load-development cross-sectional opened area of the damping openings. As an example, a type of valve means is provided on at least one of the damping openings which induces a damping effect in one direction of load on the damping opening and which seals same in the direction of back load so that no damping effect is then yielded at the damping opening. 
   The valve means can be configured, for instance, as a type of small spring plate mounted, particularly single-sidedly, and extending in front of the opening. 
   It is moreover preferred that the valve means to be configured as a type of annular small spring plate in which a fastening element sealably engages at a radially inward situated area, via which the small spring plate is secured relative to the damping opening. In this particular configuration, it is preferred to provide for the radially outer situated area of the small spring plate to be arranged so as to be movable relative to the damping opening and which bars the opening in a first position and releases a cross-sectional flow in a second position; it is particularly preferred in the second position that the flowing damper fluid releases the cited cross-sectional flow subject to a spring load of the small spring plate, respectively induces a second position of the small spring plate. 
   A check valve may in particular be provided at one or several damping openings. 
   A configuration of this type may also allow the inducing of, for example, a directional load-dependent adjustment in the damping behavior. 
   It is noted that the present invention especially provides for adjusting the damping behavior of the damping means based on a hydraulic principle and this being effected, in particular, automatically. In this given context, “hydraulic principle” is to be understood in particular as there being fluid moved between the different chambers for the purpose of damping, whereby the damping openings, channels respectively, through which the fluid moves between these chambers are configured so as to give rise to a damping effect. 
   In the sense of the present invention, damper fluid refers particularly to a liquid. For example, the damper fluid may be a runny, viscous, high viscosity or other type of liquid. Preferably, oil is employed as the damper fluid. 
   It is however noted that other damper fluids are also preferential such as, for example, gas. 
   In preferred configuration, the regulating mechanism comprises at least one control element which is arranged to be moveable relative at least one damping opening. 
   In the context of the present invention, a damping opening constitutes in particular an opening through which a damper fluid, particularly liquid, and especially oil, is moved for the purpose of damping. The relatively displaceable control element is particularly arranged so as to clear different opening cross-sectional areas of the damping openings when at different positions. 
   The control element can in particular be utilized to set the opened state or the opened cross-sectional area of one or more damping openings. 
   It is preferential, for example, that the control element can be set with respect to a pre-defined damping opening in such a manner so as to change the cross-sectional area of the damping opening. 
   It is further preferential for the control element to be set with respect to different non-contiguous damping openings and thereby seal or partly seal or, in reversed direction of load, open or partly or widely open differing damping openings successively. 
   It is particularly provided that the entire cross-sectional area of the damping opening be effective with respect to damping continuously or in finite steps or sectionally continuously or in finite steps, and in particular with respect to the damping openings related to a damping means based on the principle of hydraulic damping. 
   It is to be noted that the inventive configuration of the damping means as well as the inventive design of the damping behavior of the damping means refer in particular to such damping means in which fluids such as oil are moved between different chambers via connecting channel ports, damping openings respectively for the purpose of damping and, as necessary, solely for the purpose of damping. 
   In accordance with the invention, however, damping means may also be of a different configuration such as, for example, damping means based on a pneumatic principle or other configuration. 
   In the sense of the present invention, a damping means based on a pneumatic principle is particularly to be understood as one in which instead of a fluid like oil, gas is moved through connecting ports/channels or openings between chambers of a system of chambers in the manner as described. 
   In preferred configuration, there is unhindered fluid passage in a region or at least in one valve or the like disposed at one damping opening when the damping means, such as the spring damper system is subjected to pressure, while upon a tensile loading, the opening is kept substantially closed. 
   The damping means preferably comprises fluid-filled, especially liquid-filled chambers which are separated from one another by means of a damper piston. It is particularly preferred for the damper piston to be coupled with a piston rod which is connected to one of the load-applying segments of the spring damper system and indeed especially in a fixed manner so that there is no relative mobility. 
   It is preferential for the control element, which is preferably configured as a control rod, to be accommodated in the interior of the piston rod. It is particularly preferred for the control rod to be arranged with relative mobility with respect to the piston rod and so that it can induce different damping effects on the damping means from different axial positions. 
   In a particularly preferred configuration, the control element, such as the control rod, is arranged to be of relative mobility with respect to a housing of the spring damper system and, in fact, particularly of relative mobility with respect to all housing segments. It is particularly preferred to have two or more cylinders arranged to be axially displaceable relative one another included among the housing segments. 
   The interior of the piston road may be configured to be, for example, an axial passage channel which is, when seen from the axial direction, configured to be open at both sides. 
   An axial channel of this type may also be configured to be open at only one side and closed at the opposite side, or closed at both sides. 
   In preferred configuration, the piston rod is disposed with a casing wall encircling the piston rod interior. The interior can be, for example, arranged concentric to the casing wall. 
   In preferred configuration, the casing wall is provided with openings or damping openings configured as passage ports. In context hereto, it is especially provided that the damping openings connect the piston rod interior with the second chamber of the damping means. 
   It is moreover preferably provided for the piston rod interior to be connected with the first chamber of the damping means. Hereto, passage/damping openings may likewise be provided in the piston rod casing wall, or the connection between the first chamber of the damping means and the piston rod interior can be rendered via an opening provided in an end face of the piston rod. 
   It is particularly provided for the control rod to cover a different number of damping openings in differing axial positions. It is furthermore preferred for the control rod to cover different cross-sectional areas of the damping openings from differing axial positions. 
   As an example, without hereto constituting a restriction of the present invention, it is provided that a plurality of damping openings arranged to be axially offset with one another are configured as passage ports connecting the piston rod interior with the second chamber, whereby a connection between the piston rod interior and the first chamber of the damping means is rendered on the end face of the piston rod. In context hereto, it is preferred to provide that the control rod, contingent upon axial position, covers none or only some or all of the damping openings connection the second chamber with the piston rod interior. 
   It is furthermore preferred for the piston rod to have a tapered configuration at one end. In particularly preferred configuration, it is likewise the end section of the piston rod interior facing the first chamber, when seen in axial direction, which is of tapered configuration and open on the face side. This configuration may especially be such that the tapered end of the control rod can position in the tapering of the end region so as to substantially seal the same. Upon a displacing of the control rod in the axial direction, a cross-sectional area preferably enlarges in this configuration which defines the damping behavior of the damping means. 
   It is to be noted that the cited axially tapering sections of the damping openings, the control rod respectively, may have the same or differing sloping inclinations and exhibit a conical or non-conical surface. 
   The preferred configuration moreover provides for a positive spring as well as a negative spring. 
   The negative spring is especially a spring which has a counter effect to the positive spring and, in particular, such that the negative spring loads components arranged to be displaceable relative to one another in an effective direction that is opposite to the effective direction of the positive spring&#39;s loading of the components when the respective springs are subjected to stress and acting on the components. 
   In the case of two cylinders arranged axially displaceable relative to one another, it is especially preferred that the positive spring biases the cylinder toward a greater spatial distance, an extended position respectively, while the negative spring biases the cylinder toward less of a spatial distance, retracted position respectively. 
   As an example, the positive and negative spring may each be configured as gas springs. 
   In unloaded state of the spring damper system, the gas pressure of a gas spring configured in this manner is preferably set so as to be respectively greater than the ambient pressure. 
   It is to be noted that the spring mechanism may also comprise other spring elements such as, for instance, steel or elastomer springs, etc. 
   These other types of spring elements can be rendered in combination with gas springs or in the absence of gas springs. 
   In preferred configuration, the positive spring or the negative spring is configured as a gas spring and arranged such that one of the gas springs loads the plane of the control rod piston. This is especially provided such that the gas pressure of the positive or negative gas spring acts on a piston area of the control rod. The piston area of the control rod can in particular be provided on a piston disposed on the control rod or on an end face of the control rod. 
   It is to be noted that spring elements which are not gas springs may also act on the control rod piston plane. 
   There is furthermore another spring preferably acting on the control rod, the piston of the control rod respectively. It is especially preferential for the further spring to be a readjusting spring. In preferred configuration, the readjusting spring acts on the control rod such that same is biased toward a position in which the damping openings, their state of opening being subject to the effect of the control rod, are open. In a particularly preferred configuration, the force of the readjusting spring counters the force of the positive/negative spring loading the control rod in order to (automatically) adjust the damping behavior of the damping means. The readjusting spring may be a gas spring or a metal or elastomer spring, or may also be a differently configured spring mechanism. 
   It is preferably provided that the spring damper system comprises a first cylinder as well as a second cylinder, wherein the first cylinder is arranged axially displaceable within the second cylinder. The inner diameter of the second cylinder is preferably larger than the outer diameter of the first cylinder and in fact such that a chamber is formed radially between the cylinders. The given differences in diameter are arranged such that a gas spring is or can be disposed between the outer surface of the first cylinder and the inner surface of the second cylinder. 
   It is especially preferred to arrange a negative chamber within the gap. 
   It is furthermore preferred that such a negative chamber is separated by means of a displaceably arranged piston from a positive chamber, same particularly preferred to have an effect on the control rod. 
   It is noted that, in the sense of the present invention, the term “negative chamber” refers especially to a negative spring which is preferably configured as a gas spring while the term “positive chamber” refers especially to a positive spring which is preferably configured as a gas spring. The positive spring/chamber and especially the negative spring/chamber may, however, also be spring mechanisms of different configuration. 
   It is preferable for the gas pressure in a negative chamber configured as a gas spring and/or in a positive chamber configured as a gas spring to be adjustable to different base values for the spring damper system in unloaded state. 
   For this purpose, the corresponding valve and/or filling means are provided as necessary. 
   It is additionally pointed out that other gas springs may also be provided which can likewise be filled by means of a valve system. 
   The positive spring and/or the negative spring may also be spring mechanisms which are not gas springs. As an example, the positive and/or negative spring may be configured as an elastomer spring. 
   It is particularly preferred to mount or employ the present inventive spring damper system for the respective defined purpose between a bicycle frame and a rear assembly coupled with same. 
   In accordance with the present invention, it is preferable for the damping behavior, the damping effect of the damping means respectively, to adjust automatically with respect to rebound damping. 
   It is furthermore preferred that the damping behavior, the damping effect of the damping means respectively, adjusts automatically with respect to compression damping, or in both rebound damping as well as also compression damping. 
   An additional damping means is provided in preferred configuration to act on the regulating mechanism. The additional damping means is in particular configured such that it induces a damping of the displacing movement upon shifting of the control element. 
   The present invention particularly provides for a procedure of suspension and damping for bicycle wheels whereby a gas spring unit comprises a gas-filled chamber and whereby the damping behavior of the damping unit is automatically set contingent upon the gas pressure given within the chamber. In particular, the chamber continuing gas may act as a positive spring or as a negative spring. 
   It is to be noted that the present invention is not to be limited by its preferred and exemplary embodiments and a great variety of other special configurations to the invention can be further realized. 
   The following will describe a number of preferred aspects of the present invention in greater detail based on reference to the drawings, which show: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  a schematic representation of a first exemplary embodiment of the invention in a first loaded state of a control rod, positive spring respectively; 
       FIG. 2  the exemplary embodiment according to  FIG. 1  in a second loaded state of a control rod, positive spring respectively; 
       FIG. 3  a schematic representation of a second exemplary embodiment of the invention in a first loaded state of a control rod, positive spring respectively; 
       FIG. 4  the configuration according to  FIG. 3  in a second loaded state of a control rod, positive spring respectively; 
       FIG. 5  a schematic representation of a third exemplary embodiment of the invention in a first loaded state of a control rod, positive spring respectively; 
       FIG. 6  the configuration according to  FIG. 5  in a second loaded state of a control rod, positive spring respectively; and 
       FIG. 7  a fourth exemplary embodiment of the invention in schematic representation. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows an exemplary configuration of a spring damper system  1  in accordance with the present invention having a damping means  10  as well as a spring mechanism  12 . 
   Spring damper system  1  further comprises a first cylinder  16  as well as a second cylinder  18 . The first cylinder  16  is partly accommodated within the interior of the second cylinder  18 . A partition  26  is arranged on the end of the first cylinder facing the second cylinder  18  which separates a negative chamber  28  disposed in the second cylinder  18  from a positive chamber  30  likewise disposed in the second cylinder  18 . In  FIGS. 1-7 , a symbol “p” is used to indicate that a fluid pressure, such as a as pressure, is given within a particular chamber. 
   Said partition is especially a piston or separator piston. 
   Negative spring  28  is configured here as a gas spring. The gas spring comprises chamber  28  as well as the gas contained within. 
   In corresponding manner, positive spring  30  is configured as a gas spring and comprises a gas contained within chamber  30 . 
   The negative spring extends between the outer surface  32  of hollow cylindrical wall  34  of first cylinder  16 , the inner surface  36  of hollow cylindrical wall  38  of second cylinder  18 , the partition  26 , and the front substantially radially extending annular wall section  40  side of second cylinder  18 . 
   Second cylinder  18  is sealed relative to first cylinder  16  by means of a suitable sealant  42  in the region of the radially inward situated end of the frontal wall section  40  side of second cylinder  18 . 
   Partition  26  is sealed relative to the inner surface  36  of hollow cylindrical wall  38  by means of a suitable sealant  44 . Partition  26  is solidly coupled to the first cylinder  16 . 
   First load-applying segment  20  is configured in eyelet or grommet fashion and of substantially solid arrangement on the front end side of first cylinder  16  opposite second cylinder  18 . 
   In corresponding manner, second load-applying segment  22  is of eyelet or grommet configuration and solidly arranged on the front end side of second cylinder  18  opposite first cylinder  16 . 
   The second load-applying segment  22  arranged on second cylinder  18 , second cylinder  18  respectively, is further coupled by means of suitable receiving means  46  with piston rod  48  which, in turn, is connected to damper piston  50 . 
   Damper piston  50  is arranged between a first chamber  52  and a second chamber  54  of damping means  10 . 
   Chambers  52 ,  54  are each filled with a damper fluid in the form of an oil. 
   Piston  50  is sealed relative to first cylinder  16  by means of a suitable sealant  56  and may be moved into the cylinder  16 . 
   Damping or passage openings  58 ,  60  are provided in piston  50  which connect first chamber  52  with second chamber  54 . Small spring plates  62 ,  64  are provided in the region of passage openings  58 ,  60  which allow the oil to flow through the damping openings  58 ,  60  from the first chamber  52  into the second chamber  54 , yet which substantially prevent movement of fluid through the damping openings  58 ,  60  in the reverse direction. 
   Piston rod  48  comprises an axially and substantially concentrically extending passage opening  66 . 
   One end of the passage opening  66  leads to first chamber  52  and the other end of the passage opening  66  leads to a further chamber  68  separate from the first and second chamber  54  in additional damping means  71 . 
   The passage opening  66 , respectively interior  70  of piston rod  48 , comprises sections  72 ,  74  having different cross-sectional areas. 
   Section  72 , having a larger cross-sectional area than section  74 , faces chamber  68 . 
   A control element configured as control rod  76  extends into passage opening  66 , interior  70  of piston rod  48  respectively. A piston  78  is provided on the end of control rod  76  opposite first chamber  52 . Control rod  76  is supported via the piston  78  relative second cylinder  18 , whereby a suitable sealant  80  is provided between the second cylinder  18  and the piston  78 . Control rod  76  is furthermore supported so as to be axially displaceable relative piston rod  48  at section  74 , which has a smaller cross-sectional area compared to section  72 . 
   Section  72  of passage opening  66 , which has a larger cross-sectional area compared to section  74 , extends substantially concentrically about the control rod  76  and forms a type of annular channel  81 , through which the fluid contained in chamber  68  can flow toward first chamber  52  as well as second chamber  54 . In this regard, what is not discernible from  FIG. 1 , but is shown by example in  FIG. 7 , is that there is an opening  160  provided in the control rod  76  which extends outwardly into the interior of the control rod at its end opposite the piston  78  and which is open to the first chamber  52 . 
   A spring  82  is furthermore disposed in chamber  68  configured as, for example, a steel spring, and which biases piston  78 , control rod  76  respectively, toward the end opposite first chamber  52 . 
   Piston  78  is furthermore loaded, in the opposite direction, by the gas pressure of the gas disposed in positive chamber  30 . 
   Upon increasing gas pressure in positive chamber  30 , the control rod is increasingly biased in the direction of first chamber  52  against the force of spring  82  such that the control rod is increasingly moved toward first chamber  52 . 
   Upon decreasing gas pressure in chamber  30 , the control rod, subjected to the spring force of spring  82 , moves in the opposite direction. 
   The respective axial position of control rod  76  is thus affected by the gas pressure of the gas disposed in chamber  30  as well as by the spring force of spring mechanism  82 . 
   Spring  82  may have a constant or a variable spring constant through the displacement. 
   First piston area  84 , facing first chamber  52 , is in contact with the fluid found within chamber  68 . 
   Second piston area  86  arranged on the side of piston  78  facing the first chamber  52  is in contact with the gas found within chamber  30 . 
   Casing wall  88  of piston rod  48  exhibits substantially radially extending damping/passage openings  90 ,  92  which are arranged offset one another when seen from the axial direction of the control rod. 
   The respective opening cross-section of the damping openings  90 ,  92  is less than the opening cross-section of passage opening  66  on piston rod  48  disposed between openings  90 ,  92  and first chamber  52 . 
   When the spring damper system  1  is subject to a pressure load, as indicated by arrows  94 ,  96 , the gas pressure in chamber  30  increases. This increasing gas pressure has the effect of increasingly moving control rod  76  toward first chamber  52  until the point at which an axial equilibrium of forces on control rod  76  results. The equilibrium of forces may be in particular—at least in one or several axial positions of control rod  76 —such that the force exerted on control rod  76  by the gas pressure is compensated by the force spring  82  exerts on the control rod in the opposite axial direction. Upon the corresponding (pre-) stressing of spring  102  to be described in the following, the equilibrium of forces can furthermore include the force of—in static state—the oil disposed in first chamber  52  acting on control rod  76  in the axial direction. This force is contingent upon the oil pressure which is—especially in the static state—in turn contingent upon the tension of spring  102 . This force in particular acts counter to the force exerted on control rod  76  due to the gas pressure present in chamber  30 . It is to be noted that frictional forces as well can enter into the equilibrium of forces acting upon control rod  76  in the axial direction. 
   In the position depicted in  FIG. 1 , control rod  76  is arranged such that both damping opening  90  as well as also damping opening  92  are open and thus not covered by control rod  76 . 
   In this position, upon pressure-loading or further pressure-loading of the spring damper system, first cylinder  16  and second cylinder  18  are telescopically moved farther into one another. In so doing, damper piston  50  is moved by piston rod  48  such that first chamber  52  becomes substantially reduced in size and second chamber  54  becomes substantially enlarged in size. Upon this movement, fluid breaches second chamber  54  from first chamber  52 . 
   This movement of fluid is induced such that oil is moved through passage openings  58 ,  60  whereby, subject to the pressure of the fluid, the small spring plates  62 ,  64  open damping openings  58 ,  60  and enable the overflow of oil from first chamber  52  into second chamber  54 . The oil moreover flows from first chamber  52  through the interior  70  of piston rod  48  as well as damping openings  90  and  92  into second chamber  54 . 
   Upon rising gas pressure in chamber  30 , control rod  76  moves increasingly toward first chamber  52  so that damping opening  90  is initially closed and, in this position, oil from first chamber  52  can only overflow into second chamber  54  through damping openings  58 ,  60  as well as damping opening  92 . 
   Upon relieving of spring damper system  1 , upon the rebound damping of spring damper system  1  respectively, the spring damper system slackens, as schematically indicated by arrows  98 ,  100 . 
   In so doing, the volume in chamber  30 , which had been decreased due to the pressure load, now increases so that the gas pressure in chamber  30  drops. 
   Upon this decreasing gas pressure, control rod  76  is relieved such that, especially due to the effect of spring  82 , it moves in the direction opposite first chamber  52  and thus damping openings  90 ,  92  are cleared again at the corresponding positions, at least partly. 
   Upon this movement directed toward the relieving of the spring damper system  1  (rebound damping), oil flows from second chamber  54  into first chamber  52 . A flow through damping openings  58 ,  60  is hereby prevented by small spring plates  62 ,  64 . The oil hence flows through damping opening  92  and, as soon as damping opening  90  becomes clear, also through same as well. 
   Spring damper system  1 , further comprises a spring  102  separated from the first oil-filled chamber  52  by full floating piston  104  which, as need be, is sealed relative to first cylinder  16 . Spring  102  in the configuration according to  FIG. 1  is configured as a gas spring and thus comprises a chamber that is filled with gas. The volume, respectively pressure of the gas of spring  102  configured as a gas spring may be adjusted by means of the appropriate valve or filling means  106 . 
   A valve or filling mechanism of this type is, as necessary, also provided for filling or generating a base pressure in positive chamber  30 . Although not depicted in  FIG. 1 , such a valve means may also be provided for filling negative chamber  28 . 
   It is however to be noted that especially negative chamber  28  can also be provided as a differently configured spring mechanism such as, for example, an elastomer spring mechanism. With this type of configuration, sealant  42 , for example, can be omitted. 
   Although not shown in  FIG. 1 , an overflow can also be provided on inner surface  36  of hollow cylindrical wall  38  of second cylinder  18 , which is configured, for instance, as a groove-like channel. 
   An overflow of this type enables, especially in certain relative positions of the first  16  and the second cylinder  18 , gas to overflow between positive chamber  30  and negative chamber  28  such that a corresponding equalization of pressure is generated in at least one predefined position when positive chamber  30  and negative chamber  28  are configured as gas-filled chambers. 
     FIG. 2  depicts a second position of the spring damper system  1  according to FIG.  1 . 
   In this position, as can be seen from  FIG. 2 , control rod  76  is moved farther toward the first chamber  52  compared to the representation given in FIG.  1 . This movement induces spring  82 , subject to the effect of a higher gas pressure in chamber  30 , to be increasingly compressed. In addition, the control rod is shifted such a distance toward first chamber  52  that damping opening  90  is substantially covered. In the representation according to  FIG. 2 , an exchange of oil between first chamber  52  and second chamber  54  is rendered possible through damping opening  92 . 
     FIG. 3  depicts a schematic representation of a further exemplary embodiment of the present invention. 
   The configuration according to  FIG. 3  differs from the configuration according to  FIG. 1  especially with respect to the spring arranged in chamber  68 . While a steel or helical spring is selected in the representation according to  FIG. 1 , an elastomer spring element  120  is provided in chamber  68  in the representation in accordance with FIG.  3 . 
     FIG. 4  shows the spring damper system  1  according to  FIG. 3  in a position which corresponds substantially to the position according to FIG.  2 . 
   As can be seen from  FIG. 4 , elastomer spring element  120  in this position of control rod  76  is compressed when compared to the representation according to FIG.  3 . 
     FIG. 5  depicts another configuration of the inventive spring damper system  1  which differs from the configuration according to  FIG. 1  especially by the configuration of passage opening  66  in the area adjoining first chamber  52  as well as by the configuration of the end section facing control rod  76  in first chamber  52 . 
   In the configuration of the spring damper system  1  according to  FIG. 5 , the end section of passage opening  66  facing first chamber  52  tapers toward the first chamber  52 . 
   A corresponding tapering is also provided on end section  130  of control rod  76  facing the first chamber  52 . This tapered section  132  of control rod  76  is surrounded by a port section  134  in the position of the control rod  76  according to  FIG. 5  which is arranged between piston rod  48  and tapered section  132  of control rod  76 . The port section  134  as well as the passage opening  136  allow for a fluid connection between the first chamber  52  and the second chamber  54 . The port section  134  hereby acts as a damping opening. 
   With increasing axial displacement of control rod  76  toward load-applying segment  22 , the cross-sectional area of port section  134  enlarges so that the damping effect is reduced. 
     FIG. 6  shows the configuration of spring damper system  1  according to  FIG. 5 , in which control rod  76  is shifted further toward first chamber  52  and tapered section  132  of the control rod  76  abuts against tapered section  138  of the piston rod  48 , piston  50  respectively. In this position, port section  134  is substantially closed, thus preventing an exchange of oil between first chamber  52  and second chamber  54  through the port section. 
     FIG. 7  shows an exemplary embodiment of the present invention which comprises a plurality of features from the configuration represented in FIG.  1 . 
   A number of other or distinct features are depicted in  FIG. 7  which will be addressed to some extent in the following. 
   In the configuration according to  FIG. 7 , in addition to filling means  150  for filling chamber  102  with gas, a filling means  152  is also provided for filling second chamber  30  with gas. 
   Additionally in the configuration according to FIG.  7 —unlike in the  FIG. 1  configuration—there is no provision for a section  72  having larger cross-sectional area nor a section  74  having smaller cross-sectional area of passage opening  66 , but rather a passage opening  66  is provided which has the sections  72 ,  74  as represented in  FIG. 1  being substantially constant in their cross-sectional area. 
   Although differing from the configuration according to  FIG. 1 , the configuration according to  FIG. 7  has in fact provided control rod  76  with different cross-sectional areas. Control rod  76  has an area  154  comprising a smaller cross-sectional area, a smaller circumference respectively, as well as an area  156  arranged toward first chamber  52 —as seen from the area  154 —which has a—comparatively—larger cross-sectional area, a larger circumference respectively. Control rod  76  is directed axially in the area  156  relative piston rod  48 . 
   It is to be noted in conjunction hereto that what is particularly meant as the cross-sectional area with respect to control rod  76  is the area spanned by the outer circumferential contour. 
   It is further noted that annular channel  158  can also be formed by, for example, a combination of comparable configurations corresponding to  FIGS. 1 and 7  such that—particularly in the forming of the annular channel  158 —both a section of opening  66  having larger cross-sectional area as well as a section of control rod  76  having smaller cross-sectional area is provided. 
   With respect to the configurations having different cross-sectional areas, it must be noted that the different cross-sectional areas are in particular disposed at positions outside of chamber  68 , respectively outlying piston  78  of control rod  76  arranged as need be within chamber  68 . 
   The configuration according to  FIG. 7  also provides for chamber  68  being connected to first chamber  52 , and as required to second chamber  54 , by means of annular channel  158  in which opening  160  extends substantially radially in the interior of the control rod as well as port  162  extending from the opening  160  to the end of control rod  76  facing the first chamber  52 . This connection enables a damping effect to be generated upon the corresponding exchange of damper fluid, oil respectively, and in particular hereto, an additional damping effect which dampens the movement of the control rod upon axial displacement. 
   It is to be noted that instead of or in addition to annular channel  158 , a connecting channel may also be provided in control rod  76  to connect chamber  68  with port  162 ; there may feasibly not be an opening  160  provided in such a configuration—especially when there is no additional annular channel  158  provided. 
   Opening  160  as described on the basis of  FIG. 7  is also provided in the configurations according to  FIGS. 1-4 , as is port  162  also described on the basis of FIG.  7 . 
   This type of opening  160  as well as type of channel port  162  may also be provided for in the configuration described on the basis of  FIGS. 5 and 6 . In the configuration according to  FIGS. 5 and 6 , channel port  162  may be open in the region of the conical or tapered outer surface, instead of on the front end side of control rod  76 . This can be rendered technically, for example, by the employment of a multi-sectional control rod  76  or by sealing the facing end side of the frontal open area in connection with a further substantially radial opening. 
   An overflow  164  is furthermore provided in the configuration according to  FIG. 7  which enables a pressure equalizing, respectively an overflow of gas relative the positive and the negative chamber in a pre-defined position or position range. Such an overflow  164  may also be provided in the configurations according to  FIGS. 1-6 . 
   It is to be particularly noted with respect to FIGS.  1 -- 7  that additional damping means  71  dampen the movement of control rod  76 . This damping is induced particularly in that the damper fluid, meaning especially oil in the configurations according to  FIG. 1-7 , is moved between chamber  68  and a further chamber through the corresponding taperings, channel ports or openings respectively, the further chamber being particularly the first and/or second chamber. Ports or openings are especially annular channel  158 , respectively a correspondingly disposed port in the interior of the control rod and/or the opening and/or the port  162 . Instead of a liquid or the oil, a gas may also be employed as the damper fluid.