Adjustable Monotube Shock Absorber

• US 20100109277A1
• Filed: 11/06/2009
• Published: 05/06/2010
• Est. Priority Date: 11/06/2008
• Status: Abandoned Application

• Current Assignee: Fredrick J. Furrer
• Original Assignee: Fredrick J. Furrer
• Inventors: Furrer, Fredrick J.
• Application Number:
  US12/613,733
• Publication Number:
  US 20100109277A1
• Time in Patent Office: Days
• US Class Current: 280/124.161
• CPC Class Codes: B60G 17/08 Characteristics of fluid dampers adjusting fluid dampers in general F16F9/44 - F16F9/53
• CPC Class Codes: B60G 2202/24 Fluid damper
• CPC Class Codes: B60G 2206/41 Dampers
• CPC Class Codes: B60G 2500/104 continuous
• CPC Class Codes: F16F 9/061 Mono-tubular units
• CPC Class Codes: F16F 9/466 Throttling control, i.e. regulation of flow passage geometry F16F9/464, F16F9/465 take precedence

Abstract

A monotube shock absorber that can be adjusted remotely or otherwise, and a corresponding system are provided. The monotube shock absorber includes a body tube that houses a working piston therein and a bypass tube that is attached to but external with respect to the body tube. A control valve influences flow volume and rate of oil that passes through the bypass tube in a manner that correspondingly influences damping and/or other characteristics of the monotube shock absorber. The monotube shock absorber can include a floating piston separating a volume of gas from a volume of oil. The volumes of gas and oil may be entirely housed in the body tube or may be at least partially housed in an external reservoir that can include an anti-cavitation valve.

Claims

1. A monotube shock absorber comprising:

(a) a body tube having a cylindrical sidewall and defining,

(i) a gas cavity that houses a volume of gas therein; and

(ii) an oil cavity axially adjacent the gas cavity and housing a volume of oil therein;

(b) a rod having a first end housed in the body tube and a second end extending outwardly from an end of the body tube;

(c) a floating piston concentrically housed between the rod and an inwardly facing surface of the body tube cylindrical sidewall and defining,

(i) an interface between the gas and oil cavities and maintaining physical separation between the volumes of gas and oil; and

(ii) a floating zone corresponding to a portion of the body tube in which the floating piston axially traverses during use;

(d) a working piston connected to and traveling in unison with the first end of the rod and being positioned within and movable through the volume of oil, the working piston separating the oil cavity into,

(i) an upper oil cavity portion that is above the working piston, and

(ii) a lower oil cavity portion that is below the working piston; and

(e) an external bypass tube located outside of the body tube cylindrical sidewall and having,

(i) a lower bypass tube end fluidly connected to the lower oil cavity; and

(ii) an upper bypass tube end fluidly connected to the upper oil cavity portion,

wherein the upper bypass tube end intersects the body tube cylindrical sidewall at a location that is below a lowermost segment of the floating zone in which the floating piston operates.

2. The monotube shock absorber of claim 1, wherein the external bypass tube defines a bidirectional flow of oil therethrough when the working piston travels in a first axial direction and a second, opposing axial direction through the oil cavity.

3. The monotube shock absorber of claim 2, wherein a control valve is provided between the lower bypass tube end and the lower oil cavity portion and wherein adjusting the control valve influences oil flow characteristics within the monotube shock absorber.

4. The monotube shock absorber of claim 3, wherein the control valve is provided within a base that attaches to a bottom end of the body tube.

5. A monotube shock absorber comprising:

(a) a body tube having a cylindrical sidewall and defining an oil cavity that houses a volume of oil therein,

(b) a rod having a first end housed in the body tube and a second end extending outwardly from an end of the body tube;

(c) a working piston connected to and traveling in unison with the first end of the rod and being positioned within and movable through the volume of oil, the working piston separating the oil cavity into,

(i) an upper oil cavity portion that is above the working piston, and

(ii) a lower oil cavity portion that is below the working piston; and

(d) an external bypass tube located outside of the body tube cylindrical sidewall and fluidly connecting the upper and lower oil cavity portions with each other;

(e) an external reservoir housing a volume of gas and a volume of oil that is fluidly connected to the lower oil cavity; and

(f) a control valve operably positioned between the lower oil cavity and an end of the external bypass tube, such that a fluid flow path is defined between the control valve and the external bypass tube,

wherein adjusting the control valve influences oil flow characteristics within the monotube shock absorber.

6. The monotube shock absorber of claim 5, wherein an anti-cavitation valve is operably coupled to the external reservoir.

7. A monotube shock absorber comprising:

(a) a body tube having a cylindrical sidewall and defining an oil cavity that houses a volume of oil therein,

(b) a rod housed concentrically in the tube and having an end that extends outwardly from an end of the body tube;

(c) a working piston assembly having

(i) a piston head connected to the rod and slidingly communicating with an inner surface of the body tube cylindrical sidewall, and

(ii) a piston valving assembly permitting a volume of oil to flow axially through or past the piston head when a predetermined pressure differential is established across the piston head;

(d) a base connected to a lower portion of the body tube;

(e) an external bypass tube located outside of the body tube cylindrical sidewall, the external bypass tube having

(i) a first end attached to a location of the body tube cylindrical sidewall that is located above the piston head when the piston head is located at an uppermost position within the body tube during a rebound stroke, and

(ii) a second end attached to the base; and

(f) a control valve housed in the base and influencing a rate of flow of oil through the external bypass tube,

wherein during the rebound stroke, the piston head forces a volume of oil through a single flow path that is defined through the external bypass tube and the control valve such that manipulating the control valve adjusts rebound damping characteristics of the monotube shock absorber.

8. A remotely controlled monotube shock absorber system, comprising:

a user interface and a controller operably communicating with the user interface, the controller managing performance characteristics of multiple adjustable monotube shock absorbers, each of the multiple adjustable monotube shock absorbers including,

(a) a body tube having a cylindrical sidewall and defining an oil cavity that houses a volume of oil therein;

(b) a working piston displacing the volume of oil within the body tube;

(e) an external bypass tube located outside of the body tube cylindrical sidewall and fluidly connecting a first portion of the body tube and a second portion of the body tube; and

(f) a control valve controlling a rate of flow of oil through the external bypass tube,

wherein the controller manipulates the control valve of each of multiple monotube shock absorbers for simultaneously adjusting performance characteristics of the multiple monotube shock absorbers.