Patent Publication Number: US-10765214-B2

Title: Guide spring for a seating device and sprung seating device

Description:
TECHNICAL FIELD 
     The present disclosure relates to a guide spring for a seating device and to a sprung seating device comprising one or more guide springs. 
     BACKGROUND 
     Sprung seating devices, such as rocking stools, ideally provide axial movement of a seat. In some cases, additional lateral displacement of the seat is desired. 
     Mechanisms that provide axial and possibly lateral movement of a seat have traditionally been complex, requiring many different parts. Such mechanisms have been prone to friction, which can cause noise as the seat moves. Due to their complexity, known mechanisms have been relatively expensive. 
     Providing noise-free, sprung, vertical movement of a seat has been a particularly difficult problem to solve. Height-adjustable chairs may cause noise during vertical adjustment, which is acceptable since the adjustment is a temporary occurrence. In sprung seating devices, vertical movement of the seat coincides with even slight changes in a user&#39;s posture, and is thus a frequent occurrence. Noise-free operation is therefore very important. 
     It is an object of the present disclosure to provide an improved sprung seating device, for example a stool, which is relatively inexpensive to manufacture, eliminates or at least greatly reduces friction, is quiet, and is not subject to wear. 
     SUMMARY 
     A mechanism for an improved seating device is based on a rod which can axially move relative to a body. Two guide springs are provided to movably secure the rod within the body. A lower guide spring has an inner portion firmly connected to the rod and an outer portion firmly connected to the body. The inner portion is connected to the outer portion by a spiral coiled portion. An upper guide spring also has an inner portion firmly connected to the rod and an outer portion firmly connected to the body. Again, the inner portion is connected to the outer portion by a spiral coiled portion. 
     The mechanism may further have a plurality of stabilizing bars which are circumferentially spaced around the rod and connect the spiral coiled portion of the lower guide spring with the spiral coiled portion of the upper guide spring. The stabilizing bars may be arranged parallel to the rod. The stabilizing bars may be connected through apertures in the spiral coiled portions of the lower guide spring and the upper guide spring. 
     The mechanism may further have a lower intermediate guide spring with an inner portion firmly connected to the rod and an outer portion firmly connected to the body. The inner portion is preferably connected to the outer portion by a spiral coiled portion which turns in opposite direction of the spiral coiled portion of the lower guide spring. Similarly, an upper intermediate guide spring may be provided with an inner portion firmly connected to the rod and an outer portion firmly connected to the body, the inner portion being connected to the outer portion by a spiral coiled portion which turns in opposite direction of the spiral coiled portion of the upper guide spring. 
     When in use, the rod moves axially relative to the body when a load is placed onto the seating device, so that the guide springs deform from a flat spiral shape to a conical spiral shape with axial movement of the rod relative to the body. The guide springs may be arranged to be normally flat or normally conical. A normally flat guide spring may be arranged within the seating device biased in a conical shape. 
     The guide springs may be made of steel, fiber-reinforced plastic, or any other similarly resilient material. The guide springs may have a cross section at their spiral coiled portions with a width to height ratio greater than 2:1. Width to height ratios of up to 5:1 or even 10:1 may be used. The guide springs may be cut or punched out of a sheet of steel, in particular out of a sheet of spring steel. 
     Inevitably, gaps are formed convolutions of the spiral coiled portion of the lower guide spring and/or the upper guide spring. Those gaps may be filled with an elastomer. 
     While the guide springs may be able to absorb an axial force, it is more beneficial if the mechanism further includes a load spring which counteracts axial movement of the rod relative to the body. The load spring may be a compression spring or a tension spring. 
     An improved seating device includes a base with a base body, a seat, a rod firmly connected to the seat, a lower guide spring, and an upper guide spring. The lower guide spring has an inner portion firmly connected to the rod and an outer portion firmly connected to the base body. The inner portion of the lower guide spring is connected to its outer portion by a spiral coiled portion. Similarly, the upper guide spring has an inner portion firmly connected to the rod and an outer portion firmly connected to the base body. Here, also, the inner portion of the upper guide spring is connected to its outer portion by a spiral coiled portion. The spiral coiled portions may have two or more convolutions. An elastomer may be arranged between the two or more convolutions, filling a gap between the between the spiral convolutions. 
     The seating device may use a load spring to counteract axial movement of the rod relative to the base. The load spring may be a compression spring, an extension spring, or a combined compression and extension spring. Use of compression springs is preferred, since they provide an inherent hard stop when fully compressed and cannot be overloaded. The load spring may be a compression spring arranged between a lower end of the rod and the base. The load spring may also be a compression spring arranged around the rod between the seat and the base. 
     The seating device may have a plurality of stabilizing bars which are circumferentially spaced around the rod and connect the spiral coiled portion of the lower guide spring with the spiral coiled portion of the upper guide spring. 
     The base body of the seating device may be formed by a plurality of arms, each extending from a lower end to an upper end. The upper guide spring may be seated on the upper ends of the arms forming the base body. 
     The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a guide spring made of round wire having a conical compression spring section and a cylindrical inner spring thread section. 
         FIG. 2  is a side view of a normally conical guide spring made of wire with generally rectangular cross section. 
         FIG. 3  shows a normally flat spiral spring having a width to height ratio of 3:1 to provide enhanced lateral guidance. 
         FIG. 4  shows an alternative guide spring. 
         FIG. 5  shows yet another normally flat guide spring. 
         FIG. 6  is a perspective view of normally flat guide spring which has been laser cut from spring steel or may be molded from fiberglass-reinforced plastic. The guide spring includes radially protruding attachment extensions. 
         FIG. 7  shows a guide spring mechanism for a seating device. 
         FIG. 8  is a perspective cross sectional view of a seating device. 
         FIG. 9  shows a seating device in a normal state. 
         FIG. 10  shows a seating device in a loaded state. 
         FIG. 11  shows a seating device with height adjustable seat rod. 
         FIG. 12  shows a seating device with threaded seat rod. 
         FIG. 13  shows a seating device with conical base body. 
         FIG. 14  shows a seating device with cylindrical base body. 
         FIG. 15  is a top view of a base of a seating device. 
         FIG. 16  is a side view of the seating device using the base as in  FIG. 15 . 
         FIG. 17  is a perspective view of the seating device as in  FIG. 16 . 
         FIG. 18  shows the seating device as in  FIG. 17  with an additional compression spring. 
         FIG. 19  is a side view of a seating device with casters. 
         FIG. 20  is a cross sectional view of a seating device with a conical seat body. 
         FIG. 21  is a cross sectional view of a highly dynamic seating device. 
         FIG. 22  is a cross sectional view of an alternative seating device. 
         FIG. 23  is a partially cut view of yet another seating device. 
         FIG. 24  is a perspective view of a seating device with a lower guide spring integrally formed in a base. 
         FIG. 25  is a perspective view of a seating device with an upper guide spring attached to a bottom of a seat. 
         FIG. 26  is a perspective view of a seating device with a lower guide spring integrally formed in a base without visible gaps. 
         FIG. 27  is a cross sectional view of the guide spring as in  FIG. 26  with elastomer-filled spiral portion. 
         FIG. 28  is a partially cut open view of a seating device with two hidden guide springs and a visible load spring. 
         FIG. 29  is a partially cut open side view of another seating device. 
         FIG. 30  is a partially cut perspective view of the seating device as in  FIG. 29 . 
     
    
    
     DETAILED DESCRIPTION 
     An improved sprung seating device and its spring mechanism are based on one or more guide springs  100 , examples of which are shown in  FIG. 1  through  FIG. 6 . The guide springs may be normally flat as shown in  FIG. 3 ,  FIG. 5  and  FIG. 6 . Alternatively, guide springs may have a normally tapered shape as shown in  FIG. 1  and  FIG. 2 . 
     The guide springs  100  extend from an inner portion  110  to an outer portion  130 . A spiral coiled portion  120  connects the inner portion  110  with the outer portion  130  The inner portion  110  can move axially relative to the outer portion  130  and provides an axial force counteracting an axial deflection. The inner portion  110  can also move laterally (radially) relative to the outer portion  130 . Normally, the inner portion  110  may be arranged concentric with the outer portion  130 . The guide spring  100  creates a lateral (radial) force counteracting a lateral (radial) deflection of the inner portion  110  relative to the outer portion  130 . 
     For use in seating applications, the guide spring  100  may be configured to allow an axial movement of the inner portion  110  relative to the outer portion  130 . The maximum axial displacement of the inner portion from its normal position may be up to 10 cm, up to 13 cm, or even up to 15 cm. The lateral movement (maximum lateral displacement) may be limited to 1 cm or less. In a preferred embodiment the guide spring  100  has an outer diameter at its outer portion  130  of about 200 mm. The outer diameter is (preferably between 100 mm and 300 mm, even more preferably between 150 mm and 250 mm). The inner diameter at the inner portion  110  is about 40 mm. The inner diameter is preferably between 20 mm and 60 mm and even more preferably between 30 mm and 50 mm). 
     The response of the guide spring  100  to lateral and axial deflection can be adjusted by varying design parameters. For example, the guide spring may be made of different materials. The guide spring may be normally flat and may be cut out of a flat sheet of steel. One significant characteristic of the guide spring is the cross sectional shape of the spring at its spiral coiled portion  120 . 
     Beneficially, the cross sectional shape of the spring at its spiral coiled portion  120  may have a maximum height and a maximum width with a width to height ratio greater than two. The cross sectional shape of the spring may be generally rectangular with a width to height ratio between 2:1 and 5:1. A width to height ratio of up to 10:1 or more is possible. A spring having a width to height ratio of 10:1 or more is practically laterally immovable. Through selection of these design parameters the overall usability and “feel” of a seating device  300  in which the guide spring  100  is used can be selected. 
     Referring to  FIG. 1 , a first exemplary guide spring  100  is formed by a conical compression spring section  140 , the inner end of which extends into a cylindrical extension spring section  150 . The guide spring  100  extends between an outer portion  130  at an upper end of the conical spring section  140  and an inner portion  110  at a lower end of the cylindrical extension spring section  150 . The inner spring portion  110  and the outer spring portion  130  are connected by a spiral coiled portion  120 . The guide spring  100  as shown in  FIG. 1  may be made of wound spring steel wire with a round cross section. The cylindrical extension spring section  150  may be used to engage threads of a rod. The guide spring  100  may be used to simultaneously provide lateral guidance and an axial load force. 
     Exemplary seating devices  300  which use the guide spring  100  as shown in  FIG. 1  are illustrated in  FIG. 12 ,  FIG. 13  and  FIG. 14 . The seating device  300  as shown in  FIG. 12  comprises a base  310  with a generally cylindrical base body  320 . The base  310  comprises a plurality of radiating arms  312  which project outwardly from a lower end of the cylindrical base body  320 . Casters or wheeled supports  314  are secured to distal ends of the arms  312  for supporting the base  310  and enabling rolling movement of the base  310  on a support surface (e.g., floor). 
     A seat  350  is secured to a seat rod  200 . The seat rod  200  is held coaxially within the cylindrical base body  320  by a lower guide spring  101  and an upper guide spring  102 . The lower guide spring  101  and the upper guide spring  102  are of the type shown in  FIG. 1 . The lower guide spring  101  is oriented such that the conical compression spring section  140  is supported on lower end of the cylindrical base body  320 . The upper guide spring  102  is arranged in opposite orientation. The conical compression spring section  140  of the upper guide spring  102  is secured at an upper end of the cylindrical base body  320 . 
     The inner portion  110  of the lower guide spring  101  is axially immovably secured to the seat rod  200  in form of a threaded connection. As shown, an outer surface of the seat rod  200  contains threads  201  into which the cylindrical compression spring section  150  reaches. The inner portion of the upper guide spring  102  is axially immovably secured to the seat rod  200  in the same manner. 
     The lower guide spring  101  and the upper guide spring  102  serve two different functions: Firstly, the guide springs act as compression springs to counteract a weight placed onto the seat  350 , thereby providing a sprung seat arrangement. When a weight is placed onto the seat  350 , the lower guide spring  101  is compressed, resulting in a push force which counteracts the weight. The upper guide spring  102  is extended, resulting in a pull force which counteracts the weight. Secondly, the guide springs  101 ,  102  provide lateral guidance of the seat rod  200  within the base body  320 . 
     The lower guide spring  101  and the upper guide spring  102  are resiliently deformable in both axial direction and in lateral direction. A configuration with a wound round wire spring element as shown in  FIG. 1  is preferably used in seating devices where some lateral movement of the seat  350  is desirable. Such an active seating configuration can replicate the benefits of sitting on an exercise ball. A lateral movement of the seat  350  causes the inner portion of the upper guide spring  102  to be deflected in the same direction as the seat  350 . The inner portion of the lower guide spring  101  is deflected in opposite direction. The lateral deflection of the inner portions of the guide springs  101 ,  102  causes a stabilizing force which is directed to return the tilted seat rod  200  into an upright orientation and thereby push the seat  350  into its normal position. 
     A generally conical shaped base body  324  as shown in  FIG. 13  allows for increased lateral movement of the seat  350 , respectively increased tilt angles of the seat rod  200 . The base body  324  can be placed directly onto a floor without wheeled supports, thereby preventing movement of the base even when the seat  350  is laterally deflected. The lower guide spring  101  and the upper guide spring  102  can be of the same type or different types. For example, the lower guide spring  101  can be selected to have a larger outer diameter than the upper guide spring  102 . The seat  350  is height-adjustable by rotating the threaded seat rod  200  within the inner compression spring sections of the guide springs. To build a non-adjustable seat a regular, non-threaded seat rod may be used. 
       FIG. 14  shows a design similar to that shown in  FIG. 12  with a different base  310 . As shown, the cylindrical base body  320  is placed on top of radiating arms  312 . The seat  350  is height adjustable by rotating the threaded seat rod  200  relative to the guide springs  101 ,  102 . 
       FIG. 11  shows a configuration of a seating device  300  with a height-adjustable rod  205  which is supported by a lower guide spring  101  and an upper guide spring  102  as shown in  FIG. 2 . The height-adjustable seat rod  205  comprises a hollow cylindrical rod  203  which accommodates a coaxial inner rod  202 . The inner rod  202  can move axially within the hollow cylindrical rod  203  when a release lever  220  is pulled. The hollow cylindrical rod  203  is held within the cylindrical base body  320  of the seating device  300 . The inner portion of the lower conical guide spring  101  is firmly secured to a lower end of the hollow cylindrical rod  203 . The outer portion of the lower conical guide spring  101  rest on or is secured to a lower end of the cylindrical base body  320 . The lower inner end of the upper guide spring  102  is secured in an upper region of the hollow cylindrical rod  203  with a bracket  230 . The upper outer portion of the upper guide spring  102  is secured to an upper end of the cylindrical base body  320 . 
     The inner rod  202  extends upwardly through an opening  321  of the cylindrical base body  320 . The size of the opening  321  relative to the outer diameter of the inner rod  202  and the outer diameter of the hollow cylindrical rod  203  relative to the inner diameter of the cylindrical base body  320  determine a maximum lateral deflection of the seat  350 . The maximum lateral deflection of the seat  350  may be further controlled by providing an adjustment mechanism (not shown) to control the diameter of the openings  321 . 
     The conical guide spring  102  as shown in  FIG. 2  and as used in the seating device shown in  FIG. 11  has a generally rectangular cross section having a width and a height. The width to height ration of the spiral coiled portion of the lower guide spring  101  and the upper guide spring  102  determines the response of the guide spring  101 ,  102  to lateral and axial forces. A guide spring  101 ,  102  with a larger width to height ratio is more easily deflected axially and more resistive to lateral deflection than a guide spring with the same cross sectional surface area but a lower width to height ratio. 
     In the seating devices shown in  FIG. 11-14  the seat rod  205  is firmly attached to the seat  350  and moves axially and laterally within a base body. The base body in those embodiments is firmly attached to a base. The base may or may not be equipped with wheels to allow movement relative to a floor. An alternative configuration is shown in  FIG. 20  and  FIG. 21 . Here, a base post  206  is firmly attached to a base  310 . The seat  350  in this configuration comprises a hollow conical seat body  351  within which a lower guide spring  101  and an upper guide spring  102  are arranged. Shown in  FIG. 20  is an embodiment using the guide spring as shown in  FIG. 1 . A threaded outer surface of the base post  206  engages the inner portion of the lower guide spring  101  and the upper guide spring  102 . The outer portion of the upper guide spring  102  is attached to an upper end of the seat body  351 . The outer portion of the lower guide spring  101  is secured around an opening at the lower end of the seat body  351 . The seat  350  is height-adjustable by rotating the seat  350  and with it the lower and upper guide springs  101 ,  102  relative to the base post  206 . The conical shape of the seat body  351  provides a wide range of tilting motion of the seat  350 . The lower guide spring  101  and the upper guide spring  102  absorb axial forces placed onto the seat  350  through compression of the lower guide spring  101  and extension of the upper guide spring  102 . The guide springs also provide lateral guidance of the seat body  351 , creating a resetting force that urges the seat  350  into a normal position coaxial with the base post  206  when laterally deflected. 
     The exemplary seating device shown in  FIG. 21  utilizes the same conical seat body  351  shown in  FIG. 20  and guide springs with a generally rectangular cross section as shown in  FIG. 2 . The lower portion of the base which rests of the floor is formed as a spherical cap  311 . The base  310  and with it the base rod  206  can thus pivot about the lower base portion. Also, the seat  350  can move axially and pivot relative to the base rod  206 . The use of normally conical guide springs allows for large vertical displacement. The high degree of movability of the seat  350  as shown in  FIG. 21  typically requires some practice and/or training for a user to use comfortably. 
     Referring to  FIGS. 16 and 17 , a seating device  300  is shown in a side view and a perspective view. A top view of the base  310  of the seating device is shown in  FIG. 15 . The base  310  comprises a plurality of five arms  312  which are connected to each other at their upper ends. More specifically, the upper ends of the arms  312  are securely attached to an outer portion  130  of an upper guide spring  102 . The guide spring  102  is of the normally flat type shown in  FIG. 6 . The outer portion  130  of the guide spring  102  has radial extensions  131  with a central hole  132  therein. The upper end of the arms  312  can be secured to the guide spring  102  with screws that reach through the holes  132  to engage a corresponding thread in the upper portion of the arms  312 . 
     The guide spring  100  as shown in  FIG. 15  and  FIG. 6  comprises an outer portion  130  which is shaped as a closed ring and from which the radial extensions  131  outwardly project. An inner portion  110  is also shaped as a closed ring concentrically with the outer portion  130 . A spiral coiled portion  120  extends between the inner portion  110  and the outer portion  130  in approximately 1¼ convolutions. 
     The guide spring  100  is made of a resilient material. The guide spring  100  may e.g. be cut out of a planar sheet of spring steel. The guide spring may be cut by a laser or a water-jet out of a sheet of steel or punched out of a sheet of steel. Alternatively, the guide spring  100  can be molded, e.g. made of plastic with large fiber content. 
     A lower guide spring  101  is arranged axially spaced below the upper guide spring  102 . The lower guide spring is firmly attached to the arms  312 . More specifically, radial extensions  131  of the lower guide spring may be screwed into a lateral attachment extension  315  formed onto the arms  312 . 
     A seat rod  200  is firmly attached to a seat  350 . The seat rod  200  is securely attached to the inner portions  110  of the lower guide spring  101  and the upper guide spring  102 . 
     When no weight is placed onto the seat  350  the lower guide spring  101  and the upper guide spring  102  retain their generally flat normal orientation. In that orientation the inner portion  110 , the outer portion  130  and the connecting spiral coiled portion  120  are generally arranged within a common plane. The inner portion  110  of the guide spring is concentric with the outer portion. 
     When a weight is placed onto the seat  350  as indicated by a bold arrow in  FIG. 10 , the lower guide spring  101  and the upper guide spring  102  deform. The inner portion  110  of the springs moves downwardly below the outer portion  130 . The flat spiral shape of the spiral coiled portion  120  becomes a conical spiral shape. 
     The spiral coiled portion of  120  of the guide springs is wider than it is tall. The height of the spiral coiled portion  120  is determined by the thickness of the metal sheet from which it is cut. The width of the spiral shaped portion is determined by design of the shape which is cut out of the steel. Given its width to height ratio the guide spring resists lateral deflection of its inner portion  110  more than it resists axial deflection of its inner portion  110 . A preferably width to height ration of the coiled portion of the guide spring in this configuration is 3:1. 
     The lower and upper guide springs  101 ,  102  in the seating device as shown in  FIG. 17  have to be sufficiently strong to accommodate the weight of a maximum weight user, for example 200 kg. Consequently, the height of the guide spring has to be selected appropriately. 
     Referring now to  FIG. 18  and  FIG. 19 , an alternative design is shown which allows for significantly thinner guide springs  101 ,  102 . Here, the guide springs  101 ,  102  are provided primarily to provide lateral guidance of the seat rod  200 . The weight of a user is absorbed by a separate compression spring  370 , which may be of conventional wound wire design. A lower end of the compression spring  370  rest on top of a base plate  316  which is arranged above the lower guide spring  101 . The base plate  316  is attached jointly with the lower guide spring  101  to the base  310 . An upper end of the compression spring is arranged below the upper guide spring  102 . When a weight is placed on to the seat, the inner portion  110  of the upper guide spring  102  is now supported by the upper end of the compression spring, which transfers the compressive force through the base plate  316  into the base  310 . 
     A further improved embodiment of a seating device is shown in  FIG. 9  and  FIG. 10 . The seating device  300  comprises a base plate  313  with three vertical arms  318 . The base plate  313  and the vertical arms  318  form a base body  320 . Supported on top of an upper end of the vertical arms  318  is the outer portion  130  of an upper guide spring  102 . The outer portion  130  of the guide spring  102  may comprise attachment holes through which the guide spring  102  is screwed to the arms  312 . 
     Axially spaced below the upper guide spring  102  is a parallel lower guide spring  101 . An outer portion  130  of the lower guide spring  101  is firmly attached to the vertical arms  318 . The lower guide spring  101  and the upper guide spring  102  are arranged coaxially. A seat pole  200  is fixedly attached to inner portions  110  of the lower guide spring  101  and the upper guide spring  102 . A seat  350  is firmly attached at an upper end of the seat pole  200 . 
     Arranged between a lower end of the seat pole  200  and the base plate  313  is a conical compression spring  370 . When in use, the conical compression spring  370  creates a counter-force to any weight placed onto the seat  350 . The weight is indicated by a bold arrow in  FIG. 10 . 
     The upper and lower guide springs are primarily configured to provide lateral guidance of the seat post  200  within the base body  320  and contribute little axial force. To strengthen the guide spring&#39;s rigidity against lateral deflection even when the guide spring is axially deflected as shown in  FIG. 10 , circumferentially spaced stabilizing bars  400  are provided. The stabilizing bars  400  are symmetrically spaced along the spiral coiled portion of the lower and upper guide springs, thereby ensuring that the lower and upper guide springs must deflect symmetrically. As shown in  FIG. 9 , three stabilizing bars  400  may be used. However, more than three stabilizing bars may be provided. The use of stabilizing bars  400  has proven effective in tests, reducing lateral deflection of the guide springs when subjected to the same lateral force to less than 25% of the deflection without stabilizing bars. The additional stabilizing bars  400  can increase lateral rigidity of the guide spring arrangement fourfold. 
     The stabilizing bars  400  extend parallel to the seat rod  200 . The stabilizing bars  400  may be formed as threaded bars which extend through apertures in the spiral coiled portions of the lower and upper guide spring. In such a configuration the spiral coiled portions may be secured to the stabilizing bars between two nuts. One skilled in the art will recognize that alternative attachment configurations exist. The stabilizing bars  400  prevent, in sections, a twisting of the spiral coiled portion when deflected from a flat shape into a conical shape, thereby increasing rigidity. 
     Due to the inevitably asymmetrical nature of a spiral the use of a single upper guide spring  102  and a single lower guide spring  101  may lead to asymmetrical forces and bias the seat  350  in one direction when a weight is placed thereon. 
     To counter such asymmetry a mechanism for a seating device as shown in  FIG. 7  may be used. Here, the single upper guide spring  101  is replaced by a pair of oppositely arranged upper guide springs  102 ,  104 . The single lower guide spring  101  is replaced by a pair of oppositely arranged lower guide springs  101 ,  103 . Within each pair of oppositely arranged guide springs one guide spring is arranged with its spiral coiled portion  120  in a clockwise orientation which the adjacent guide spring has a spiral coiled portion in a counter-clockwise orientation. For simplicity of illustration only apertures  122  for attaching stabilizing bars are shown in  FIG. 7 , but not the stabilizing bars themselves. Nevertheless, the quad-spring-configuration as shown in  FIG. 7  may use stabilizing bars between each of the guide springs  101 , 103 , 102 , 104 . 
     As shown in  FIG. 7 , the central rod may consist of a solid inner rod  200  and outer hollow cylindrical spacer elements  210 . The inner portions of the guide springs may be clamped in-between two outer hollow cylindrical spacer elements  210 , thereby securing the axial orientation of the inner portion of the guide spring. 
     Referring now to  FIG. 8 , a seating device  300  is shown in a perspective cross sectional view. The seating device utilizes a base  310  as disclosed in U.S. Pat. No. 9,894,998 which is hereby incorporated by reference. The base  310  allows a tilting motive of the seating device  300 . A generally cylindrical base body  320  secures the outer portions of a lower guide spring  101  and an upper guide spring  102 . The upper and lower guide spring provide axial movement of a seat rod  200 . The width to height ratio of the spiral coiled portion of the guide springs is approximately 20 mm to 3 mm. Given this ratio, the guide springs are very inelastic in respect to lateral movement and function as frictionless axial bearings. When in use, the force of a user&#39;s weight is transferred from the seat  350  through the seat rod  200  and a compression spring  370  into a base plate  316  of the base  310 . The base body  320  is hidden from external view within a bellows-shaped outer body  327 . 
     Referring now to  FIG. 22 , a base body  320  in shape of a spherical segment  322  is provided. An outer portion  130  of an upper guide spring  102  rest on an upper opening of the spherical segment  322 . A lower guide spring  101  is arranged within the base body and securely held within the base body by interior attachment arms  323 . 
     An embodiment based on two oppositely biased guide springs  101 ,  102  is shown in  FIG. 23 . Here, the outer portion  130  of a both the lower guide spring  101  and the upper guide spring  102  are firmly attached to an annular retaining ring  380  which is arranged at an upper end of a generally cylindrical base body  320 . The upper guide spring  102  is a normally flat spring which is biased into a conical shape. The inner portion of the upper guide spring  110  is arranged above its outer portion  130 . The lower guide spring  101  is biased in the opposite direction, with its outer portion  130  being arranged above its inner portion  110 . The lower guide spring  101  and the upper guide spring  102  thus form two coaxial cones with proximal bases and distant vertices. This arrangement is notably different from the arrangement shown in  FIG. 13  and  FIG. 14  where two conical guide springs are arranged coaxially with their vertices pointing towards each other. 
     The dynamic behavior of a seat, in particular its resistance to lateral movement, can be affected by several factors:
         1) The vertical distance between the upper guide spring and the lower guide spring. The further apart the guide springs are arranged, the better they resists lateral forces.   2) The vertical distance of the outer portion of the guide spring relative to the inner portion of the guide spring. The closer the inner and outer portion of a guide spring are to being in a common plane, the better it resists lateral forces.   3) The design of the guide spring, in particular the width to height ratio of its spiral coiled portion. The larger the width to height ratio, the better the guide spring resists lateral forces.       

     Referring to  FIG. 4 , a spiral guide spring having a rectangular profile in a normally conical arrangement is shown. The spring rises on its periphery. The upper end leads to the center and serves to hold the seat rod. This results in the advantage that a free intermediate space is created and the active part of the spring (the spring swings with its main weight on its outer diameter) can be covered, in order to avoid injury. 
     Referring to  FIG. 5 , a spiral spring in normally flat arrangement made of round steel wire is shown. It serves as a tension spring/compression spring, and at the same time as a lateral guide spring. The use of spring wire is inexpensive, but requires a greater vertical distance between the springs, so that the lateral resetting is present with sufficient strength. 
     Referring to  FIG. 24  and  FIG. 25 , a stool is shown in which the lower guide spring  101  is integrally formed within a base body. The base body  320  may be injection molded and made of fiberglass reinforced plastic. The upper guide spring here is a normally tapered spiral spring, the upper outer portion of which is directly screwed onto a lower side of the seat  350 . 
     A further beneficial improvement of the stool as in  FIG. 24  and  FIG. 25  is shown in  FIG. 26  and  FIG. 27 . Here, the base body  320  also includes an integrated lower guide spring which includes a spiral coiled portion  120  extending more than one convolution between an inner portion and an outer portion. The spiral coiled portion is made of a resilient material, e.g. made of (spring) steel or fiberglass reinforced plastic. The spiral coiled portion can, when exposed to an external force, resiliently deform. In previously discussed embodiments a gap is formed between the convolutions of the spiral coiled portion  120 . In the embodiment shown in  FIG. 26  and  FIG. 27  that gap is filled with an elastic material  124 . The elastic material may be an elastomer, in particular rubber. In a particularly preferred embodiment the guide spring is made of steel or fiber-reinforced plastic (a first material) and gaps between convolutions of the spiral coiled portion of the guide spring are filled with rubber (a second material) which is bonded by vulcanization to the steel or plastic. The elastomer-filled guide spring offers an aesthetically pleasing design when no visible openings are desired. Also, a potential for accumulation of dirt entering the base through the lower guide spring is prevented, as is a potential interference with the seating device by external objects becoming jammed within the lower guide spring. A guide spring without gaps can prevent pinching accidents, and may be required to meet safety guidelines when the guide spring is externally accessible. 
     The elastomer-filled guide spring may be formed by over molding or vulcanizing an elastomer around a previously formed guide spring. Alternatively, an elastomer layer may be sandwiched between two guide springs, e.g. between an upper guide spring and an upper intermediate guide spring as shown in  FIG. 7 . 
     The elastomer is selected to be highly elastic, such that deformation of the guide spring between a flat shape and a conical shape is not impacted. In use, the elastomer which fills the gaps of the spiral shaped portion of the guide spring deforms jointly with the steel portion of the guide spring. 
     Yet another alternative seating device is shown in  FIG. 28 . Here, the compression spring  370  is arranged above the upper guide spring  102  between the seat  350  and the base body  320 . The guide springs  101 ,  102 , are hidden from view inside the base body  320  whereas the compression spring  370  is visible from the outside. In other embodiments both guide springs and the load spring are hidden inside a base (see e.g.  FIG. 8 ) or all springs are visible (see e.g.  FIG. 18 ). 
       FIG. 29  and  FIG. 30  show an arrangement of a seating device with lower guide spring  101  and upper guide spring  102  within a generally cylindrical base body without the use of a separate load spring. 
     Although the present disclosure relates to seating devices it is noted that the disclosed guide springs can be beneficially used in many different applications beyond seating devices in which a frictionless axial movement of an object within a range of axial displacement is desirable. Therefore, while the present invention has been described with reference to exemplary embodiments, it will be readily apparent to those skilled in the art that the invention is not limited to the disclosed or illustrated embodiments but, on the contrary, is intended to cover numerous other modifications, substitutions, variations and broad equivalent arrangements that are included within the spirit and scope of the following claims.