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EP-3594526-B1 - SPRING RATE ADJUSTER

EP3594526B1EP 3594526 B1EP3594526 B1EP 3594526B1EP-3594526-B1

Inventors

  • SINTORN, TORKEL

Dates

Publication Date
20260506
Application Date
20180713

Claims (15)

  1. Shock absorber (100) comprising a cylinder (7), a piston rod (2) and a piston (6) attached to said piston rod (2), wherein said piston (6) is arranged in said cylinder (7); a damping chamber comprising a compression damping chamber (8) defined by the cylinder and by the piston rod, a rebound damping chamber (11), and a damping medium; wherein the shock absorber (100) further comprises a gas spring in functional connection with the damping chamber, wherein at least one characteristic of said gas spring is adjustable by a user-adjustable feature arranged within the piston rod, wherein said user adjustable feature affects the enclosing area of the damping chamber, thereby indirectly affecting the gas spring through said functional connection; characterized in that a flexible membrane (9) divides a space between an outer shell (1) and the cylinder (7) into different compartments, one compartment being a compression spring chamber (10) of the gas spring and another the rebound damping chamber (11).
  2. Shock absorber (100) in accordance with claim 1, wherein said at least one characteristic of said gas spring is indirectly adjustable by adjusting the space available to the gas spring.
  3. Shock absorber (100) in accordance with claim 1, wherein the air spring and the damping chamber are separated by means of a flexible membrane (9).
  4. Shock absorber (100) in accordance with claim 1, wherein the user adjustable feature comprises a moveable piston (12) arranged within the piston rod (2).
  5. Shock absorber (100) in accordance with claim 4, wherein the moveable piston (12) is moveable within the piston rod (2) through a threaded connection (13).
  6. Shock absorber (100) in accordance with claim 4, wherein the moveable piston (12) is adjustable from the outside through a worm drive (14).
  7. Shock absorber (100) in accordance with claim 1, wherein the gas spring comprises a compression spring chamber (10) and a rebound spring chamber (18).
  8. Shock absorber (100) in accordance with claim 7, wherein a pressure balancing port (19) is arranged on the piston rod (2), said pressure balancing port (19) interconnecting the compression spring chamber (10) and the rebound spring chamber (18) of the gas spring.
  9. Shock absorber (100) in accordance with claim 8, wherein said pressure balancing port (19) will interconnect said compression spring chamber (10) and said rebound spring chamber (18) at a predetermined point during a stroke of the piston rod (2).
  10. Method for adjusting a characteristic of a gas spring in a shock absorber, said shock absorber (100) comprising - a cylinder (7), - a piston rod (2) and - a piston (6) attached to said piston rod (2), said piston (6) being arranged in said cylinder (7) and wherein a damping chamber comprising a compression damping chamber (8) defined by the cylinder and by the piston rod, and a rebound damping chamber (11) , a damping medium, a flexible membrane (9), and wherein the flexible membrane (9) divides a space between an outer shell (1) and the cylinder (7) into different compartments, one compartment being a compression spring chamber (10) and another the rebound chamber (11); - a gas spring in functional connection with the damping chamber; and - a user-adjustable feature arranged within the piston rod (2); wherein the method comprises the step of adjusting at least one air spring characteristic by applying said user adjustable feature, wherein said user adjustable feature affects the enclosing area of the damping chamber, thereby indirectly affecting the gas spring through said functional connection.
  11. Method in accordance with claim 10, wherein a characteristic is a ride height of the shock absorber.
  12. Method in accordance with claim 10, wherein a characteristic is a spring rate of the shock absorber.
  13. Method in accordance with claim 10, wherein a characteristic is a balance between a compression spring chamber and a rebound spring chamber of the shock absorber.
  14. Bicycle comprising a shock absorber in accordance with any of claims 1-9.
  15. Bicycle in accordance with claim 14, wherein the shock absorber is a rear suspension shock absorber and/or a front suspension shock absorber.

Description

Technical field The present specification generally relates to the field of suspensions and in particularly discloses a shock absorber with adjustable air spring characteristics. Technical background Shock absorbers and damping systems are used for damping of the relative movement between the wheel and the chassis of a vehicle, such as a car, a motorcycle or a bicycle. Conventionally, bicycles are provided with a shock absorbing fork and sometimes also a shock absorbing rear wheel suspension. Such shock absorbers generally comprise a damping unit and a coil spring or an air spring. If it is deemed necessary to change spring characteristics of a coil spring shock absorber, pre-tensioning can generally be adjusted by an adjustable counter surface and if the spring rate needs to be adjusted, another coil spring having the desired properties can be used. When it comes to adjustments of prior art gas spring shock absorbers, the pressure in one or more air chambers can normally be adjusted by adding or removing gas therefrom and if the spring rate needs to be changed, volume spacers can be rearranged, removed and/or replaced in order to obtain the wanted setup. Various shock absorber systems for vehicles, including bicycles, are known in the prior art. For instance, US 2002/175035 A1 discloses a spring damper system for bicycles having a first load-applying segment, a second load-applying segment, at least one spring mechanism and one damping means. The spring damper system comprises a gas spring that may be adjusted by means of filling means to adjust a base value in the spring damper system in the unloaded state. Summary of the invention However, such rearranging/removing/replacing of volume spacers has proven to be tedious, time consuming and rather complicated such that a normal user of for example a mountain bike normally lacks both the skills and the equipment required to do so. Accordingly, it would be desirable to provide an improved shock absorber where at least one characteristic of the air spring can be readily adjusted without having to disassemble the shock absorber and which does not require any, or at least very few, tools and a minimum of technical skills. The invention is based on the realization that a characteristic of the air spring in a hydropneumatic shock absorber can be changed from the outside by affecting indirectly the gas spring through the chamber containing the damping media. Since the damping media is incompressible and by arranging the gas spring and the damping chamber in functional connection with each other, it is possible to change the volume available to the gas spring by changing the enclosing area of the damping chamber. E.g. by reducing the available volume within the shock absorber, the volume available to the gas spring will be reduced and e.g. the spring rate will be affected. The above mentioned advantages are achieved by a shock absorber, a method and a bicycle according to the independent claims. Some embodiments are defined in the dependent claims. According to a first aspect of the invention a shock absorber is provided which comprises a cylinder, a piston rod and a piston attached to said piston rod. The piston is arranged in the cylinder and a damping chamber comprising a damping media is defined in the cylinder. Further, the shock absorber comprises a gas spring which is in functional connection with the damping chamber and at least one characteristic of the gas spring is adjustable by a user-adjustable feature which is arranged within the piston rod. This user adjustable feature affects the enclosing area of the damping chamber, thereby indirectly affecting the gas spring through the functional connection between the two. Hereby, a shock absorber is achieved which is easy and quick to adjust and which do not require any special tools or skills. In comparison with the very time consuming and elaborate work of replacing volume spacers as it is required in prior art shock absorbers, the shock absorber of the present invention invites a user to frequently experiment with different setups, thereby contributing to the achieving of an optimized suspension setup. With the prior art solution, the user would typically abstain from adjusting the volume spacers and accept the original setup, simply because it involved too much and too complicated work. The shock absorber of the present invention also allows for adaptation to different oil volumes. If, for example during maintenance, the oil level of the shock absorber is not refilled to the exact same level as that prior to maintenance, the shock absorbers of the prior art would not have the same setup as prior to maintenance. With the present invention, a differing oil level can be compensated for my means of the user adjustable feature. During manufacture, all shock absorbers can be given the same properties even though the oil level may vary to a certain extent between the separate shock absorbers. With the present inven