Pendulum stool
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- VESUV IP HOLDING UG
- Filing Date
- 2024-08-07
- Publication Date
- 2026-06-17
Smart Images
Figure EP2024072359_13022025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Swing stool
[0003] The invention relates to a so-called pendulum stool, as is known in principle, for example, from EP 2 427 081 B1. It is a piece of seating furniture with a seat, a column, a base, a spring mechanism for raising and lowering the seat, and a pendulum mechanism for exerting pendulum movements of the column by means of the seat. The pendulum mechanism promotes a "dynamic" sitting position with an upright posture, which is beneficial, among other things, for back health.
[0004] The disadvantage of the design there is the relatively complex pendulum mechanism with a large number of individual components that have to be coordinated with one another, whereby rubber elements that are particularly difficult to design and manufacture are required.
[0005] The object of the invention is to provide a pendulum stool that is as simple and cost-effective to manufacture as possible, which has a long service life and a high level of seating comfort.
[0006] The object is achieved according to the invention by a pendulum stool having the features of claim 1.
[0007] Accordingly, the invention discloses a one-legged rocking stool with a seat, a foot plate and a central column arranged between the seat and the foot plate, wherein the central column comprises a coil spring and a gas pressure spring with a pressure cylinder and a piston rod, wherein the pressure cylinder is provided at least in a central region with a casing made of an elastic foam, wherein the coil spring is fastened to the foot plate at one end, projecting substantially perpendicularly from the same, and the pressure cylinder with the casing at the other end is pushed into the coil spring and fixed therein in a clamping fit, wherein the casing is arranged between the pressure cylinder and the windings of the coil spring, and wherein the piston rod carries the seat.
[0008] In this way, a pendulum mechanism is realized using particularly simple means, which combines a long service life with high ergonomic comfort.
[0009] In an advantageous embodiment, the elastic foam of the casing is made of foam rubber. Foam rubber has, among other properties, the ability to become soft and simultaneously lubricious when moistened with soap solution, making it easy to insert the gas spring into the coil spring. As the soap solution dries, the frictional resistance and stiffness of the material increase again, so that a secure clamping fit is formed when dry. The foam rubber intermediate layer prevents direct metal-to-metal contact between the pressure cylinder and the coil spring, which would cause wear and operating noise.
[0010] It is advisable that the outer diameter of the casing in the unloaded, unsoaped normal state is slightly larger than the inner diameter of the coil spring, so that after insertion assisted by the soap solution, the gas pressure spring fits tightly in the coil spring.
[0011] The tipping point of the center column of the pendulum stool according to the invention, with the pendulum bearing implemented here, is located directly above the footplate, i.e., at most a few centimeters above the footplate. Preferably, the tipping point of the center column is less than 10 cm, more preferably less than 7 cm, even more preferably less than 5 cm, and most preferably less than 3 cm above the footplate.
[0012] This is preferably achieved by pushing the pressure cylinder as far as possible (up to the stop) from above into the helical spring so that it rests directly or indirectly on the base plate at the bottom, forming temporary support and / or tipping points on the base plate or on an abutment arranged on the base plate, in particular when loaded by a seated person.
[0013] The coil spring of the pendulum stool is, particularly in a load-free state, i.e. without a seated user, attached to the base plate at one end substantially perpendicular to the latter. The present inventor has found that the coil spring is ideally manufactured such that it can be attached to the base plate at one end substantially perpendicular to the latter without further inclination compensation. However, the coil spring may have variations, possibly due to production, which initially prevent a substantially perpendicular alignment of the coil spring to the base plate. In this context, it is contemplated within the scope of the present invention that the pendulum stool preferably comprises an inclination adjustment in order to compensate for such inclination variations and enable a substantially perpendicular alignment of the coil spring to the base plate.Such an inclination adjustment can be implemented in various ways, allowing for an angle between the coil spring and the base plate that deviates from a right angle. For this purpose, the inclination adjustment preferably has a first side height of a first side that is greater than a second side height of a second side, wherein the first side is preferably arranged substantially opposite the second side, so that an inclination is created between the first side and the second side with respect to the base area of the inclination adjustment.By providing various inclination adjustments with different dimensions and ratios between the first side height and the second side height, the inclination adjustment can advantageously be selected from a plurality of inclination adjustments which, depending on the deviation of the coil spring, compensates for the inclination in such a way that the coil spring can be fastened to the base plate, projecting essentially perpendicularly from the latter. Within the scope of the present invention, it is advantageous to arrange the inclination adjustment preferably between the base plate and the coil spring. An inclination adjustment can be implemented, for example, using an inclination compensation wedge or an inclination compensation disc. An inclination adjustment in the form of an inclination compensation ring is particularly preferred. An inclination compensation ring preferably has a projection that runs around at least some sections.Such a projection is preferably designed to engage with the coil spring and thus prevent it from slipping or sliding. Alternatively or additionally, an inclination adjustment can advantageously be connected to the coil spring, for example, by bonding it to the coil spring with an adhesive, especially silicone, before it is placed vertically on the base plate during the manufacturing process.
[0014] Advantageously, a silicone disc is arranged on or above the base plate as a support for the pressure cylinder. Silicone is inexpensive and produces minimal wear and low noise, even under high pressure and friction loads.
[0015] To increase abrasion resistance in the most stressed areas, the printing cylinder advantageously has a protective cap made of hard plastic at the lower end, in a section free from the casing. For the same reason, the printing cylinder advantageously has a protective ring made of hard plastic at the upper end, in a section free from the casing.
[0016] A preferred material for the hard plastic of the protective cap and the protective ring is polyamide, especially nylon.
[0017] In an advantageous embodiment, the coil spring is fastened to the base plate by means of a disc-like clamping plate screwed to the base plate, wherein the clamping plate has a collar that at least partially surrounds or engages over the lowermost coil turn of the coil spring. In a preferred variant, in the final assembly state, the clamping plate can be located between the base plate and a fastening plate enclosed by the coil spring. The fastening plate is firmly connected to the base plate by means of metric threaded screws and fixes the clamping plate located between the fastening plate and base plate, which in this way presses the coil spring firmly against the base plate. The fastening plate can have a receptacle on its upper side into which the above-mentioned silicone disc, which acts as an abutment, is inserted.
[0018] Conveniently, the coil spring is made of steel.
[0019] Finally, for user comfort and customization, it is preferable for the seat height of the rocking stool to be adjustable using an adjustment mechanism integrated into the gas spring. The seat is preferably padded.
[0020] To dampen the pendulum motion, a damper can be provided. This consists of a sleeve that surrounds the coil spring of the pendulum stool and has an internal thread that matches the coil spring. Depending on whether the damper is "screwed" further up (toward the seat) or down (toward the footplate), the damping becomes weaker or stronger. The damping effect of the damper is thus advantageously adjustable.
[0021] In a process step considered to be independently inventive in a method for manufacturing a rocking stool, the pressure cylinder provided with the casing is moistened on the outside of the casing with a lubricant, in particular a soap solution, and in this state is inserted into the coil spring. After the soap solution dries, the gas spring sits immovably in the coil spring. Instead of soap solution, water, an aqueous solution, or an oil or an oily liquid can also be used.
[0022] The inventive rocking stool has a number of advantageous properties. The innovative central column enables a simple modular design consisting of a few, simple individual parts. The user can use the rocking stool for an extended period and only replace individual parts as needed. The low tipping point ensures secure, dynamic seating. Because the tipping point is located very low, balancing can be achieved in the middle range of movement without great resistance. At the edges, the coil spring catches the user, creating a feeling of security and the user is not afraid of tipping over. When rocking while seated, the user thus has complete freedom and can safely utilize the entire range of movement. The even, flat footplate also provides the greatest possible foot clearance. The user's feet can move freely up to the central column both when turning and when standing up.Only a slight edge at the edge of the footplate is noticeable. This serves as a guide to the end of the footplate. This allows for unobstructed standing. The seat of the pendulum stool preferably resembles a bucket seat or a piano seat (or a bicycle seat, depending on the orientation of the stool). It is preferably oval in shape, which optimally guides the user's pelvis.
[0023] An embodiment of the invention is explained in more detail below with reference to schematic drawings. It shows:
[0024] FIG. 1 shows an isometric view of a pendulum stool according to the invention,
[0025] FIG. 2 shows the pendulum stool from FIG. 1 in side view,
[0026] FIG. 3 shows the pendulum stool in side view, during a pendulum deflection,
[0027] FIGS. 4A and 4B show a base plate and a central column
[0028] Section of the pendulum stool in longitudinal section,
[0029] FIG. 5 a clamping plate, a mounting plate and a silicone washer,
[0030] FIG. 6 shows an assembled assembly of clamping plate, fastening plate, and silicone washer for use with the pendulum stool. FIG. 7 shows a protective cap and a protective ring for use with the pendulum stool.
[0031] FIG. 8 shows an optional damper for the pendulum movement of the pendulum stool in different views (from above, from the side, from below),
[0032] FIG. 9 shows a section through the damper along section line AA in FIG. 8, and
[0033] FIG. 10 is an isometric view of the damper from above.
[0034] FIG. 11 is an exploded view of the damper,
[0035] FIG. 12 shows another exploded view of the damper from a different perspective,
[0036] FIG. 13A shows the pendulum stool with a tilt adjustment, in side view, during a pendulum deflection;
[0037] FIGS. 13B and 13C show a section of the rocking stool comprising a base plate and a central column with a tilt adjustment, in longitudinal section;
[0038] FIG. 13D shows a tilt adjustment ring in side view;
[0039] FIG. 13E shows a perspective view of a tilt adjustment ring.
[0040] Identical or similar elements are provided with the same reference numerals in the drawings.
[0041] The ready-to-use, assembled, one-legged rocking stool 2, shown in FIG. 1 in an isometric view and in FIG. 2 in a side view in the unloaded basic state, comprises as main components a preferably upholstered seat 4, a largely rigid base plate, and a center column 8 arranged therebetween. The center column 8 comprises a coil spring 10, which is firmly connected to the base plate 6 at its lower end, into which a pressure cylinder 12 of a gas pressure spring 14 is inserted from above and locked by a clamping connection (see also FIGS. 4A and 4B, or correspondingly FIGS. 13B and 13C with inclination adjustment 65). The gas pressure spring 14 further comprises a piston which, in an actuated position, is axially displaceable in the pressure cylinder 12, with the piston rod 16 protruding upwards from the pressure cylinder 12 and from the coil spring 10. As shown in FIG.4B, the pressure cylinder 12 contains gas, preferably nitrogen, which is shown as pressure gas volume 641.The piston rod 16 is arranged displaceably in the pressure cylinder 12. The gas pressure of the compressed gas volume 641 pushes the piston rod 16 outwards. The pressure of the gas in the compressed gas volume 641 is preferably higher than the ambient pressure. FIG. 4A shows the pressure cylinder 12 without the compressed gas volume 641, i.e. in a state in which the piston rod 16 is fully retracted. The seat 4 is fastened to the upper end of the piston rod 16. By means of an actuating lever 18, the gas pressure spring 14 can be moved in a conventional manner from a locking position to a confirming position, and the seat height can thus be adjusted, depending on how far the piston rod 16 protrudes upwards from the pressure cylinder 12 (seat height adjustment).
[0042] According to FIGS. 4A and 4B, the coil spring 10 is firmly connected to the base plate 6 at its lower end by means of a clamp closure 20. The clamp closure 20, shown exploded in FIG. 5 with its individual components and assembled in FIG. 6, comprises a disk-like clamp plate 22 with a central region resting on the base plate 6 and with a collar 24 formed on the edge and forming approximately half a coil turn. The contour of the collar 24 corresponds to the contour of the coil spring 10, so that in the final assembly state, the collar 24 at least partially engages around or over the lowermost turn of the coil spring 10, which projects vertically upward from the base plate 6, and presses it against the base plate 6. For counter-locking, a fastening plate 26, inserted into the coil spring 10 and screwed to the clamp plate 22 and the base plate 6, presses the assembly downward against the base plate 6.The upwardly projecting collar 24 of the clamping plate 22 forms an edge surround for the fastening plate 26 resting on the central region of the clamping plate 22. The fastening plate 26, in turn, has a circumferential edge surround 28 on its upper side, into which a silicone disc 30 is precisely inserted, as shown in FIG. 6. The function of the silicone disc 30 is explained in more detail below.
[0043] For screwing using fastening screws 44 (not shown), the base plate 6, the clamping plate 22, and the fastening plate 26 have corresponding screw holes, wherein the screw holes of the fastening plate 26 are provided with threaded holes 42, 44, while the other screw holes are purely through-holes. A fastening screw screwed into the central through-hole 42 connects the fastening plate 26 to the clamping plate 22. This assembled component is fastened to the base plate 6 during assembly from the underside of the base plate 6 using suitable screws, in particular head and / or hexagon socket screws (Allen key) that engage in the three through-threaded holes 44. This screw connection thus connects the coil spring 10 to the base plate 6 in a force-fitting manner.
[0044] The helical spring 10 is preferably made of steel and has a constant diameter in the axial direction. As already mentioned, the pressure cylinder 12 of the gas pressure spring 14 is pushed into the helical spring 10 from above and is mounted therein so that it cannot be axially displaced by means of a clamping connection. As indicated in FIG. 4, the pressure cylinder 12 is pushed completely into the helical spring 10 and fills it essentially over its entire length. The pressure cylinder 12 sits at the lower end, preferably with a protective cap 36 attached, on top of the silicone disk 30 connected to the base plate 6. This means that the helical spring 10 can be subjected to bending stress when seated at the lower end, just above the base plate 6, when subjected to a corresponding load, as shown in FIG.3, whereby typically the lower end of the pressure cylinder 12 (or its casing) is in point contact with the silicone disc 30 and thus rests indirectly on the mounting plate 26 and ultimately indirectly on the base plate 6. The part of the center column 8 located above the bending or tilting point 32 is largely rigid. This realizes the desired function as a pendulum stool with a tilting point 32 just above the base plate 6. In a sense, the otherwise rigid center column 8 is connected to the base plate 6 in an articulated manner at the lower end by the described construction, with the lower region of the coil spring 10 providing the necessary flexibility. This means that the coil spring itself acts as a pendulum joint. The seat height suspension in the axial direction, on the other hand, is preferably provided predominantly by the gas pressure spring 14.
[0045] In order to be able to easily insert the pressure cylinder 12 of the gas spring 14 from above into the cylindrical interior of the coil spring 10 during assembly, and to achieve the desired clamping closure after insertion into the end position, the pressure cylinder 12 has a cylindrical metallic base body whose constant outer diameter is slightly smaller than the inner diameter of the coil spring 10. A casing 34 made of an elastic foam, in particular of sponge rubber, is attached, in particular glued, to the base body. The casing 34 forms a hollow cylinder enclosing the base body of the pressure cylinder 12, preferably over a large part of the entire longitudinal extent of the pressure cylinder 12.The thickness of the casing 34 (typically 2-4 millimeters) is preferably dimensioned such that the outer diameter of the casing 34 is normally slightly larger than the inner diameter of the coil spring 10. During assembly, the casing 34 is moistened from the outside with a soap solution. The soap foam makes the foam material slippery. This allows the covered pressure cylinder 12 to be easily pushed into the coil spring 10, slightly deforming the casing 34. Once the soap has dried and the foam material has expanded somewhat, the pressure cylinder 12 can no longer be pulled out of the coil spring 10 or displaced relative to it under normal operating load. The assembly is, so to speak, "rock solid."In addition, the casing 34 prevents direct contact between the metallic base body of the pressure cylinder 12 and the metallic coils of the coil spring 10, thereby avoiding rattling, grinding, and similar noises. However, pendulum movements at the upper and lower ends of the pressure cylinder 12 can lead to relatively large compressive forces between the pressure cylinder 12 and the coils of the coil spring 10, resulting in correspondingly high levels of abrasion, which the elastic foam casing 34 may not be able to withstand in the long term, or only withstand with difficulty. The same applies to the tipping point that develops under weight load at the lower end between the pressure cylinder 12 and the silicone disk 30. In these highly stressed areas, the pressure cylinder 12 is advantageously provided with a casing or sheath made of abrasion-resistant hard plastic, such as polyamide, especially nylon.Specifically, a downwardly closed, precisely fitting protective cap 36 (see FIG. 7) made of hard plastic is pushed onto or into the lower end of the pressure cylinder 12 and clamped into place, so that in particular potential contact points between the underside of the protective cap 36 and the silicone disc 30 are protected. Especially in interaction with the silicone disc 30, abrasion is therefore low despite high stress, and noise is effectively suppressed. A protective ring 38 made of hard plastic is advantageously pushed onto the upper end of the pressure cylinder 12 and clamped into place. The protective ring 38 can have a radially projecting collar 40 at its upper end, covering the uppermost coil of the helical spring 10. The outer diameter of the protective cap 36 and the protective ring 34 is each selected so that they fit in the space between the helical spring 10 and the pressure cylinder 12.A further ring 39, which overlaps the coil spring 10, can be pushed onto the protective ring 38 as a screen.
[0046] To manufacture the pendulum stool 2 from the individual components, it is advisable to first fix the clamping plate 22 and the fastening plate 26 to the coil spring 10 and screw them together, and if necessary, insert the silicone plate 30. The assembly is then screwed to the base plate 6. The pressure cylinder 12 of the gas spring 14 is provided with the casing 34 and, if necessary, with a protective cap 36 at the lower end (alternatively, the protective cap 36 is inserted into the coil spring 10 and the pressure cylinder 12 is inserted later). The casing 34 is sprinkled or rubbed with soap solution on all sides, and the gas spring 14 prepared in this way is pushed into the free end of the coil spring 10 to the desired end position. Then, the protective ring 38 and then the screen 39 are pushed on from above. Finally, the seat 4 and, if necessary,the operating lever 18 for the height adjustment is mounted on the piston rod 16 of the gas spring 14.
[0047] The term "base plate" used here should be interpreted broadly. Instead of the preferred design shown in the figures as a solid, flat disc, a design as a spoked wheel with the center column 8 mounted in the area of the wheel hub could also be provided. The base plate can be made of metal, preferably steel, or plastic, for example, or alternatively of steel with wood or linoleum veneer applied to it.
[0048] Figures 1 to 4 show an optional damper 50, which can be used to dampen and / or limit the pendulum movements of the pendulum stool 2. The damper 50 is shown in detail in Figures 8 to 11. In principle, it is a ring or a hollow cylindrical sleeve which, in the final assembly position, engages or encloses the center column 8 and in particular its pressure cylinder 12 (see also FIG. 4). An internal thread 54 is formed in the inner wall of the sleeve, which is matched to the contour of the coil spring 10, so that the damper 50 can be turned up or down on the coil spring 10 with little play after assembly and, depending on the rotational position, can be moved down or up into a desired position in which the damper 50 assumes a clamp fit on the coil spring 10.
[0049] An axially extending slot 52 in the outer surface of the outer ring 58 of the sleeve corresponds to a rib 52 or a linear projection on the half-shell 60 (see also the next paragraph). The slot and rib 52 interlock and fix the outer ring 58 to the half-shell 60. A collar 62 and a screw 56 fix the outer ring 58 to the half-shells 60 after assembly. The outer ring 58 and the two half-shells 60 thus form a unit that can be rotated up and down on the coil spring as required. The damper 50 preferably consists of two inner half-shells 60, in particular made of plastic, specifically nylon (a polyamide), and an outer ring 58, in particular made of aluminum. The contour of the internal thread 54 is formed in the half-shells 60.During assembly, the two half-shells 60 are placed on the coil spring 10 so that they complement each other to form a solid ring, and the outer ring 58 is slid over it with as little gap as possible, with the slot and rib 52 fitting together and being able to be secured, for example, with a screw 56. The half-shells 60 are advantageously pressed apart at their end faces, where they abut, with small compression springs 64 to prevent rattling during operation.
[0050] If the damper 50 is located relatively high up on the coil spring 10, it has practically no effect on the oscillation or pendulum behavior of the pendulum stool 2. The further the damper 50 is moved downwards towards the base plate 6 and thus towards the tipping point 32, the more it restricts the tilting mobility of the coil spring 50 and thus dampens or limits the pendulum behavior.
[0051] As can be seen in FIGS. 13A, 13B and 13C, in a case in which the coil spring 10 may have production-related variations that initially do not allow a substantially perpendicular alignment of the coil spring 10 to the base plate 6, this inclination variation can be compensated for by means of an inclination adjustment 65. The inclination adjustment 65, here an inclination compensation ring 65, is particularly clearly visible in FIGS. 13D and 13E. The inclination compensation ring 65 makes it possible to compensate for an angle between the coil spring 10 and the base plate 6 that deviates from a right angle, so that the coil spring 10 can be fastened substantially perpendicularly to the base plate 6. The inclination compensation ring 65 has a first side height, here 5 mm, of a first side a, which is greater than a second side height, here 6 mm, of a second side b, wherein the first side is arranged substantially opposite the second side.In other words, an inclination in relation to the base area c is provided between the first side a and the second side b, here - with a diameter d of the inclination compensation ring 65 of 77.0 mm, this results in an inclination angle a of 89.21°.
[0052] As can be seen in FIGS. 13A, 13B, and 13C, the inclination adjustment 65 is preferably arranged between the base plate 6 and the coil spring 10. The inclination compensation ring 65 has a projection 652 extending around the inner ring circumference 651. The projection 652 is designed to engage the coil spring 10 and thus prevent it from slipping or sliding, which is immediately apparent from FIG. 13B.
[0053] List of reference symbols
[0054] 2 pendulum stools
[0055] 4 seats
[0056] 6 Footplate
[0057] 8 Central column
[0058] 10 coil springs
[0059] 12 printing cylinders
[0060] 14 Gas spring
[0061] 16 Piston rod
[0062] 18 operating levers
[0063] 20 clamp closure
[0064] 22 clamping plates
[0065] 24 collars
[0066] 26 Mounting plate
[0067] 28 Border edging
[0068] 30 silicone discs
[0069] 32 Tipping Point
[0070] 34 Sheathing
[0071] 36 protective cap
[0072] 38 protective ring
[0073] 39 Ring or screen
[0074] 40 Collar of protective ring 38
[0075] 42 through-hole thread
[0076] 44 through-hole thread
[0077] 50 dampers
[0078] 52 Slot and rib
[0079] 54 internal threads
[0080] 56 screw
[0081] 58 outer ring
[0082] 60 half shell
[0083] 62 collar of half shell 60
[0084] 64 Compression spring Compressed gas volume Inclination adjustment, inclination compensation ring inner ring circumference projection
Claims
Claims 1.A one-legged rocking stool (2) with a seat (4), a footplate (6), and a central column (8) arranged between the seat (4) and the footplate (6), wherein the central column (8) comprises a helical spring (10) and a gas pressure spring (14) with a pressure cylinder (12) and a piston rod (16), wherein the pressure cylinder (12) is provided at least in a central region with a casing (34) made of an elastic material, preferably elastic foam, wherein the helical spring (10) is secured at one end to the footplate (6) so as to project substantially perpendicularly therefrom, and the pressure cylinder (12) with the casing (34) at the other end is pushed into the helical spring (10) and is clamped therein, wherein the casing (34) is arranged between the pressure cylinder (12) and the windings of the helical spring (10), and wherein the piston rod (16) carries the seat (4), wherein the tipping point (32) of the central column (8) is located directly above the base plate (6).
2. Swing stool (2) according to claim 1, wherein the elastic foam is foam rubber.
3. Pendulum stool (2) according to claim 1 or 2, wherein the outer diameter of the casing (34) in the unloaded normal state is slightly larger than the inner diameter of the coil spring (10).
4. Pendulum stool (2) according to one of the preceding claims, wherein the pendulum stool (2) comprises an inclination adjustment (65), preferably arranged between the base plate (6) and the coil spring (10).
5. Pendulum stool (2) according to one of the preceding claims, wherein the pressure cylinder (12) is pushed so far into the helical spring (10) that it rests directly or indirectly on the foot plate (6), forming support and / or tipping points when loaded by a seated person.
6. Pendulum stool (2) according to one of the preceding claims, wherein a silicone disc (30) is arranged on or above the base plate (6) as an abutment for the pressure cylinder (12).
7. A pendulum stool (2) according to any one of the preceding claims, wherein the pressure cylinder (12) has a protective cap (36) made of hard plastic at the lower end, in a section free from the casing (34).
8. Swing stool (2) according to one of the preceding claims, wherein the pressure cylinder (12) has a protective ring (38) made of hard plastic pushed onto the upper end in a section free from the casing (34).
9. Swing stool (2) according to claim 7 or 8, wherein the hard plastic is nylon.
10. A rocking stool (2) according to any one of the preceding claims, wherein the helical spring (10) is fastened to the base plate (6) by means of a disc-like clamping plate (22) screwed to the base plate (6), wherein the clamping plate (22) has a collar (24) which at least partially surrounds or engages over the lowermost coil turn of the helical spring (10). 11 . Pendulum stool (2) according to claim 10, wherein the clamping plate (22) lies between the base plate (6) and a fastening plate (26) enclosed by the coil spring (10).
12. Pendulum stool (2) according to claim 10 in conjunction with claim 6, wherein the fastening plate (26) has a receptacle on the upper side into which the silicone disc (30) is inserted.
13. Pendulum stool (2) according to one of the preceding claims, wherein the coil spring (10) is made of steel.
14. A swing stool (2) according to any one of the preceding claims, which is height adjustable by means of an adjustment mechanism integrated into the gas pressure spring (14).
15. A rocking stool (2) according to one of the preceding claims, comprising a damper (50) which has a sleeve surrounding the coil spring (10) and having an internal thread (54) adapted to the coil spring (10).
16. A method for producing a pendulum stool (2) according to one of the preceding claims, wherein the pressure cylinder (12) provided with the casing (34) is moistened on the outside of the casing (34) with a lubricant, preferably a soap solution, and in this state is inserted into the helical spring (10).