Shock absorber with variable bypass damping

• US 6,244,398 B1
• Filed: 09/09/1998
• Issued: 06/12/2001
• Est. Priority Date: 05/15/1997
• Status: Expired due to Term

• Current Assignee: K2 Corporation (Newell Brands Inc.)
• Original Assignee: K2 Bike, Inc. (Newell Brands Inc.)
• Inventors: Jones, Edward C. Jr., Girvin, Robert H.
• Primary Examiner(s): Oberleitner, Robert J.
• Assistant Examiner(s): KRAMER, DEVON C
• Application Number:
  US09/152,137
• Time in Patent Office: 1,007 Days
• Field of Search: 188/266.7, 188/282.5, 188/316, 188/317, 188/319.1, 188/322.15, 188/322.5, 280/275, 280/276
• US Class Current: 188/316
• CPC Class Codes: B60G 17/01941 characterised by the use of piezoelectric elements, e.g. sensors or actuators
• CPC Class Codes: B62K 25/286 the shock absorber being connected to the chain-stay via a linkage mechanism
• CPC Class Codes: F16F 9/46 allowing control from a distance , i.e. location of means for control input being remote from site of valves, e.g. on damper external wall attachment of valve units to cylinders F16F9/325
• CPC Class Codes: F16F 9/466 Throttling control, i.e. regulation of flow passage geometry F16F9/464, F16F9/465 take precedence

Abstract

A dampener for a shock absorber of a vehicle, such as a bicycle, is mounted within a telescoping front fork including a stanchion tube and a coaxial slide tube. The dampener includes an internally received hydraulic fluid sleeve that defines a hydraulic chamber in which a piston assembly is disposed. Movement of the piston assembly through hydraulic fluid within the hydraulic chamber is selectively adjusted by metering the flow of bypass hydraulic fluid to the back side of the piston assembly by adjusting a fluid bypass assembly disposed longitudinally within the stanchion tube. The responsive valve assembly includes outlet and inlet ports, and biased bypass valves that move between open and closed positions. In response to sensed velocity and/or displacement of the piston assembly, thereby adjusting the damping of the shock absorber.

Claims

1. A dampener for a shock absorber, comprising:

a fluid chamber containing a fluid;

a piston disposed within the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass assembly coupled to the fluid chamber, the fluid bypass assembly having a bypass channel with an outlet portion, a first port and a second port in fluid communication with the fluid chamber, the bypass channel permitting fluid to flow through the outlet portion and operably bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side, the fluid b pass assembly being fully contained in the fluid chamber; and

a valve in the bypass channel and operable to control the flow of the fluid through the bypass channel, the valve being in fluid communication with the second port and being movable to a closed position for blocking flow of the fluid through the bypass channel.

2. The dampener of claim 1 wherein the valve is movable from an open position to the closed position in response to one of the extent of displacement of the piston and the velocity of displacement of the piston.

3. A dampener for a shock absorber, comprising:

a fluid chamber containing a fluid;

a piston disposed within the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass assembly coupled to the fluid chamber, the fluid bypass assembly having a bypass channel with an outlet portion, a first port and a second port in fluid communication with the fluid chamber, the bypass channel permitting fluid to flow through the outlet portion and operably bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side; and

a valve in the bypass channel and operable to control the flow of the fluid through the bypass channel, the valve being in fluid communication with the second port and being movable to a closed position for blocking flow of the fluid through the bypass channel, wherein the fluid is a first fluid, the fluid chamber has a first chamber portion containing the first fluid and a second chamber portion containing a second fluid, a chamber seal is disposed in the fluid chamber and separates the first and second fluids, the chamber seal being movable within the fluid chamber between first and second positions, the chamber seal in the first position at least partially blocking the second port, the chamber seal in the second position being spaced apart from the second port allowing the first fluid to move into the second port.

4. The dampener of claim 3 wherein the chamber seal is movable from the first position to the second position in response to one of the extent of displacement of the piston and the velocity of displacement of the piston.

5. The dampener of claim 3 wherein the second fluid is a compressible gas and the chamber seal is movable to the second position upon compressing the gas.

6. A dampener for a shock absorber, comprising:

a fluid chamber having a chamber wall and containing a fluid;

a piston disposed within the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass assembly coupled to the fluid chamber, the fluid bypass assembly having a bypass channel with an outlet port, a first inlet port and a second inlet port each extending through the chamber wall and in direct fluid communication with the fluid chamber, the bypass channel permitting fluid to flow through the outlet port and operably bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side, the piston being movable between a first piston position and a second piston position, in the first inlet piston position both the outlet port and the first inlet port are on the piston'"'"'s first side, and in the second piston position the outlet port is on the piston'"'"'s second side and the first inlet port and second inlet ports are on the piston'"'"'s first side allowing the fluid to bypass the piston; and

a valve in the bypass channel and operable to control the flow of the fluid through the bypass channel, the valve being movable to a closed position for blocking flow of the fluid through the bypass channel.

7. The dampener of claim 6 wherein the piston is movable to a third piston position blocking the first inlet port and restricting the fluid from flowing into the bypass channel.

8. A dampener for a shock absorber, comprising:

a fluid chamber containing a fluid;

a piston disposed within the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass assembly coupled to the fluid chamber, the fluid bypass assembly having a bypass channel with an outlet portion, a first port and a second port in fluid communication with the fluid chamber, the bypass channel permitting fluid to flow through the outlet portion and operably bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side; and

a valve in the bypass channel and operable to control the flow of the fluid through the bypass channel, the valve being in fluid communication with the second port and being movable to a closed position for blocking flow of the fluid through the bypass channel, wherein the fluid bypass assembly includes;

a bypass housing with an inlet channel and an outlet channel in fluid communication with each other through the first and second ports, the outlet channel includes the outlet portion, the inlet channel having an inlet aperture in fluid communication with the fluid chamber, the first port being intermediate the inlet aperture and the second port; and

a bypass member connected to the piston and in fluid communication with the outlet channel, the bypass member positioned to allow the fluid to move out of the outlet channel and from the piston'"'"'s first side to the second side bypassing the piston; and

a valve in the bypass channel and operable to control the flow of the fluid through the bypass channel, the valve being in fluid communication with the second port and being movable to a closed position for blocking flow of the fluid through the bypass channel.

9. The dampener of claim 8 wherein the bypass member has a first end connected to the piston and a second end at least partially disposed in the outlet channel for movement therein.

10. The dampener of claim 9 wherein the piston has a fluid passageway therethrough, and the bypass member extends through the piston'"'"'s fluid passageway.

11. The dampener of claim 8 wherein the bypass member is positionable in the outlet channel to cover the first port and block the fluid from flowing into the outlet channel through the first port.

12. A dampener for a shock absorber, comprising:

a fluid chamber containing a fluid;

a piston disposed within the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass channel with an outlet portion, a first port and a second port in fluid communication with the fluid chamber, the bypass channel permitting fluid to flow through the outlet portion and operably bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side; and

a valve in the bypass channel adjacent to the second port and being movable toward a closed position for blocking flow of the fluid through the bypass channel toward the outlet in response to one of the extent of displacement of the piston and the velocity of displacement of the piston the valve being movable to the closed position in response to the fluid moving from the fluid chamber into the second port.

13. The dampener of claim 12, further composing a second valve in the bypass channel and being movable to a closed position in response to the fluid moving through the bypass channel toward the second port.

14. A dampener for a shock absorber, comprising:

a fluid chamber having a first chamber portion containing a first fluid and a second chamber portion containing a second fluid;

a piston disposed within the fluid chamber for movement within the first chamber portion under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass assembly coupled to the fluid chamber, the fluid bypass assembly having a bypass channel with an outlet port, a first inlet port, and a second inlet port each extending through the fluid chamber and being in fluid communication with the first chamber portion, the bypass channel permitting fluid to operably bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side when the piston is positioned intermediate the outlet port and the first inlet port;

a chamber seal disposed in the fluid chamber and separating the first and second fluids, the chamber seal being movable to a first position to block the second inlet port and to a second position away from the second inlet port; and

a valve in the bypass channel and operable to control the flow of the first fluid through the bypass channel, the valve being in fluid communication with the second inlet port and being movable to a closed position for blocking flow of the first fluid to the outlet port.

15. The dampener of claim 14 wherein the valve is movable from the first position to the second position in response to one of the extent of displacement of the piston and the velocity of displacement of the piston.

16. A dampener for a shock absorber, comprising:

a fluid chamber having a first chamber portion containing a first fluid and a second chamber portion containing a second fluid;

piston disposed within the fluid chamber for movement within the first chamber portion under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass assembly coupled to the fluid chamber, the fluid bypass assembly having a bypass channel with an outlet port, a first inlet port and a second inlet port each in fluid communication with the first chamber portion, the bypass channel permitting fluid to operable bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side when the piston is positioned intermediate the outlet port and the first inlet port;

a chamber seal disposed in the fluid chamber and separating the first and second fluids, the chamber seal being movable within the fluid chamber between first and second positions, in the first position the chamber seal at least partially blocks the second inlet port, and in the second position the chamber seal is spaced apart from the second inlet port allowing the first fluid to move into the second inlet port; and

a valve in the bypass channel and operable to control the flow of the first fluid through the bypass channel, the valve being in fluid communication with the second inlet port and being movable to a closed position for blocking flow of the first fluid to the outlet port.

17. The dampener of claim 16 wherein the chamber seal is movable from the first position to the second position in response to one of the extent of displacement of the piston and the velocity of displacement of the piston.

18. The dampener of claim 16 wherein the second fluid is a compressible gas and the chamber seal is movable to the second position upon compressing the compressible gas.

19. A dampener for a shock absorber, comprising:

a fluid chamber having a first chamber portion containing a first fluid and a second chamber portion containing a second fluid;

a piston disposed within the fluid chamber for movement within the first chamber portion under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass assembly coupled to the fluid chamber, the fluid bypass assembly having a bypass channel with an outlet port, a first inlet port, and a second inlet port each extending through the fluid chamber and being in fluid communication with the first chamber portion, the bypass channel permitting fluid to operably bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side when the piston is positioned intermediate the outlet port and the first inlet port;

a chamber seal disposed in the fluid chamber and separating the first and second fluids; and

a valve in the bypass channel and operable to control the flow of the first fluid through the bypass channel, the valve being in fluid communication with the second inlet port and being movable to a closed position for blocking flow of the first fluid to the outlet port, wherein the piston is movable between a first piston position and a second piston position, in the first piston position the outlet port, the first inlet port, and the second inlet port are on the piston'"'"'s first side, and in the second piston position the outlet port is on the piston'"'"'s second side and the first inlet port and the second inlet port are on the piston'"'"'s first side allowing the fluid to bypass the piston.

20. The dampener of claim 19 wherein the piston is movable to a third piston position blocking the first inlet port and restricting the first fluid from flowing into the bypass channel.

21. The dampener of claim 19 further comprising a second valve in the bypass chamber and being movable to a closed position blocking back flow of the first fluid from the outlet port to the first inlet port.

22. The dampener of claim 19 wherein the bypass channel has a fluid path between the first inlet port and the outlet port, and the valve is at least partially in the fluid path movable to control the flow of the first fluid from moving to the outlet port.

23. The dampener of claim 19 wherein the second inlet port is positioned to allow the first fluid to move the valve toward the closed position in response to one of the extent of displacement of the piston and the velocity of displacement of the piston.

24. The dampener of claim 19, further comprising a biasing member biasing the valve away from the closed position.

25. The dampener of claim 19 wherein the piston, the chamber seal, and the fluid chamber are aligned along a common axis and the bypass channel is axially off set from the axis.

26. A dampener for a shock absorber, comprising:

a fluid chamber containing fluid;

a piston disposed in the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides; and

a bypass assembly coupled to the fluid chamber permitting the fluid to operably bypass the piston, the bypass assembly including;

a bypass housing with an inlet channel and an outlet channel in fluid communication with each other through first and second ports, the inlet channel having an inlet aperture in fluid communication with the fluid chamber and the first port being intermediate the inlet aperture and the second port the piston being axially movable in the fluid chamber relative to the bypass housing;

a bypass member connected to the piston and in fluid communication with the outlet channel, the bypass member being movable with the piston as a unit relative to the bypass housing, the bypass member positioned to allow the fluid to move out of the outlet channel and from the piston'"'"'s first side to the second side bypassing the piston; and

a valve disposed in the inlet channel and being operable to control the flow of the fluid through the second port into the outlet channel, the valve being movable to a closed position for blocking flow of the fluid through the second port.

27. The dampener of claim 26 wherein the valve is movable toward a closed position blocking fluid from passing through the second port in response to one of the extent of displacement of the piston and the velocity of displacement of the piston.

28. The dampener of claim 26 wherein a portion of the bypass member is positionable in the outlet channel adjacent to the first port blocking the fluid from flowing into the outlet channel through the first port.

29. The dampener of claim 28 wherein the piston has a fluid passageway therethrough, and a second portion of the bypass member extends through the piston'"'"'s fluid passageway.

30. The dampener of claim 26 wherein the valve is biased toward an open position.

31. The dampener of claim 26, further comprising an adjustable valve spaced apart from the bypass assembly and in fluid communication with the outlet chamber and allowing a selected flow of the fluid to move from the fluid chamber into the outlet channel.

32. The dampener of claim 26, the dampener being for a telescoping suspension strut of a vehicle having a ground engaging member and a frame, further comprising a stanchion tube having an end securable to one of the ground engaging member and the frame, the stanchion tube defining the fluid chamber.

33. The dampener of claim 32, further comprising a slide tube coaxially mounted with the stanchion tube for telescoping during compression and rebound of the shock absorber.

34. A dampener for a shock absorber, comprising:

a fluid chamber containing fluid;

a piston disposed in the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides; and

a bypass assembly coupled to the fluid chamber permitting the fluid to operably bypass the piston, the bypass assembly including;

a bypass housing with an inlet channel and an outlet channel in fluid communication with each other through first and second ports, the inlet channel having an inlet aperture in fluid communication with the fluid chamber and the first port being intermediate the inlet aperture and the second port;

a bypass member connected to the piston and in fluid communication with the outlet channel, the bypass member positioned to allow the fluid to move out of the outlet channel and from the piston'"'"'s first side to the second side bypassing the piston, the bypass assembly being filly contained in the fluid chamber; and

a valve disposed in the inlet channel and being operable to control the flow of the fluid through the second port into the outlet channel, the valve being movable to a closed position for blocking flow of the fluid through the second port.

35. A dampener for a shock absorber, comprising:

a fluid chamber containing fluid;

a piston disposed in the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides; and

a bypass assembly coupled to the fluid chamber permitting the fluid to operably bypass the piston the bypass assembly including;

a bypass housing with an inlet channel and an outlet channel in fluid communication with each other through first and second ports, the inlet channel having an inlet aperture in fluid communication with the fluid chamber and the first port being intermediate the inlet aperture and the second port;

a bypass member connected to the piston and in fluid communication with the outlet channel, the bypass member positioned to allow the fluid to move out of the outlet channel and from the piston'"'"'s first side to the second side bypassing the piston, the piston and bypass member being movable as a unit within the fluid chamber, the piston being movable between a first position with the bypass member blocking the first port and a second position with bypass member blocking the second port; and

a valve disposed in the inlet channel and being operable to control the flow of the fluid through the second port into the outlet channel, the valve being movable to a closed position for blocking flow of the fluid through the second port.

36. A dampener for a shock absorber, comprising:

a fluid chamber containing fluid;

a piston disposed in the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides; and

a bypass assembly coupled to the fluid chamber permitting the fluid to operably bypass the piston, the bypass assembly including;

a bypass housing with an inlet channel and an outlet channel in fluid communication with each other through first and second ports, the inlet channel having an inlet aperture in fluid communication with the fluid chamber and the first port being intermediate the inlet aperture and the second port;

a bypass member connected to the piston and in fluid communication with the outlet channel, the bypass member positioned to allow the fluid to move out of the outlet channel and from the piston'"'"'s first side to the second side bypassing the piston, the bypass member being movable between first and second positions, the bypass member being spaced apart from the first and second ports when in the first position allowing the fluid to flow through at least one of the first and second ports, the bypass member blocking at least one of the first and second ports when in the second position; and

a valve disposed in the inlet channel and being operable to control the flow of the fluid through the second port into the outlet channel, the valve being movable to a closed position for blocking flow of the fluid through the second port.

37. The dampener of claim 36 wherein the bypass member blocks both the first and second ports when in the second position.

38. A dampener for a telescoping suspension strut of a vehicle having a ground engaging member and a frame, comprising:

a stanchion tube having an end securable to one of the ground engaging member and the frame, and defining an internal fluid chamber containing fluid;

a piston disposed within the fluid chamber for movement under the force of a shock acting on the shock absorber, the piston having first and second sides;

a fluid bypass assembly coupled to the fluid chamber, the fluid bypass assembly having a bypass channel with an outlet portion, a first port and a second port in fluid communication with the fluid chamber, the bypass channel permitting fluid to flow through the outlet portion and operably bypass the piston and flow from the piston'"'"'s first side to the piston'"'"'s second side;

a valve in the bypass channel and operable to control the flow of the fluid through the bypass channel, the valve being in fluid communication with the second port and being movable to a closed position for blocking flow of the fluid through the bypass channel; and

a slide tube coaxially assembled with a stanchion tube for telescopic compression, wherein the piston assembly, the bypass channel and the valve are mounted internally within the stanchion tube and the slide tube.

39. The dampener of claim 38 wherein the valve is movable to the closed position in response to one of the extent of piston displacement in the fluid chamber and the velocity of piston displacement.

40. The dampener of claim 38 wherein the piston assembly, bypass channel and valve are all defined at least partially within the stanchion tube.

41. The method of claim 40, further comprising, moving the valve to the closed position preventing a portion of the fluid from bypassing the piston through the bypass assembly when the piston is in the second position.

42. A method of adjusting stiffness of a dampener for a shock absorber, comprising:

moving a piston through a fluid in a fluid chamber of the dampener, the piston moving from a first position to a second position, the piston having first and second sides;

moving a portion of the fluid into a fluid bypass assembly and along a fluid bypass channel therein, the fluid bypass assembly being coupled to the fluid chamber and having an outlet port, a first port and a second port in fluid communication with the fluid chamber, and a valve being coupled to the bypass channel and in fluid communication with the second port, the outlet port, first port and second port being on the first side of the piston when the piston is in the first position to provide a first stiffness and the outlet port being on the second side of the piston and the first and second ports being on the first side of the piston when the piston is in the second position to provide a second stiffness different than the first stiffness;

moving the valve from an open position toward a closed position as the piston moves to the second position and the fluid moves along the along the bypass channel;

restricting with the valve the flow of fluid through the second port to the outlet port in response to an extent of piston displacement or velocity of piston displacement; and

moving the restricted flow of fluid from the first side of the piston through the outlet port and into the fluid chamber on the second side of the piston with the restricted flow of fluid bypassing the piston to adjust the stiffness of the dampener as the piston moves to the second position.

43. The method of claim 42, further comprising blocking the first and second ports preventing the flow of fluid from moving therethrough.

44. The method of claim 42, further comprising blocking the first port with the piston preventing the flow of fluid from moving therethrough.