Abstract:
A vehicle suspension damper includes: a cylinder and a piston assembly, wherein the piston assembly includes a piston; a working fluid within the cylinder; a bypass cylinder surrounding the cylinder and defining a cylindrical bypass channel; an adjustable bypass port fluidly coupling an interior of the cylinder and the cylindrical bypass channel; and a remotely operable bypass valve slidably disposed within the cylindrical bypass channel, the remotely operable bypass valve configured for, upon actuation of an actuator coupled with the remotely operable bypass valve, adjusting a flow of the working fluid through the adjustable bypass port.

Description:
FIELD OF THE INVENTION 
     Embodiments of the present technology generally relate to a damper assembly for a vehicle. More specifically, certain embodiments relate to a remotely operated bypass valve used in conjunction with a vehicle damper. 
     BACKGROUND 
     Vehicle suspension systems typically include a spring component or components and a damping component or components. Typically, mechanical springs, like helical springs are used with some type of viscous fluid-based damping mechanism and the two are mounted functionally in parallel. In some instances, features of the damper or spring are user-adjustable. What is needed is an improved method and apparatus for adjusting damping characteristics, including remote adjustment. 
     SUMMARY OF EMBODIMENTS 
     Embodiments include a vehicle suspension damper that comprises: a cylinder and a piston assembly, wherein the piston assembly includes a piston; a working fluid within the cylinder; a bypass cylinder surrounding the cylinder and defining a cylindrical bypass channel; an adjustable bypass port fluidly coupling an interior of the cylinder and the cylindrical bypass channel; and a remotely operable bypass valve slidably disposed within the cylindrical bypass channel, the remotely operable bypass valve configured for, upon actuation of an actuator coupled with the remotely operable bypass valve, adjusting a flow of the working fluid through the adjustable bypass port. 
     Embodiments also include: remotely operable bypass valve for operation within a vehicle suspension damper, the remotely operable bypass valve comprising: a threaded plug coupled with an actuator, wherein the threaded plug is configured for being angularly displaced within a cylindrical bypass channel about a longitudinal axis of the threaded plug relative to a piston in response to an operation of the actuator, wherein the cylindrical bypass channel is defined by a bypass cylinder surrounding a cylinder of the vehicle suspension damper; a rod disposed adjacent to the threaded plug, wherein the rod is configured for moving along the longitudinal axis within the cylindrical bypass channel in response to an angular displacement experienced by the threaded plug; and a sleeve disposed adjacent to the rod, wherein the sleeve is configured for moving along the longitudinal axis within the cylindrical bypass channel in response to the moving by the rod, wherein the sleeve provides an adjustment to a flow of a working fluid through an adjustable bypass port fluidly coupling an interior of the cylinder and the cylindrical bypass channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features can be understood in detail, a more particular description may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore into to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIG. 1  is a section view showing a vehicle suspension damper with a bypass, in accordance with an embodiment. 
         FIG. 2  is an enlarged section view showing a valve of the bypass in an open position, in accordance with an embodiment. 
     
    
    
     The drawings referred to in this description should be understood as not being drawn to scale except if specifically noted. 
     DESCRIPTION OF EMBODIMENTS 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the present invention, and should not necessarily be construed as preferred or advantageous over other embodiments. In some instances, well known methods, procedures, objects, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present disclosure. 
     Overview of Discussion 
     Embodiments disclosed herein provide a damping mechanism for a vehicle suspension damper in which a bypass cylinder surrounds a cylinder of the vehicle suspension damper, thereby defining a cylindrical bypass channel. An adjustable bypass port fluidly couples the interior of the cylinder with the cylindrical bypass channel. A remotely operable bypass valve functions within the cylindrical bypass channel to meter the flow of damping fluid from the interior of the cylinder, through the adjustable bypass port leading to the cylindrical bypass channel, and ultimately to a rebound portion of the cylinder. The remotely operable bypass valve may be operated remotely and manually by a user via an actuator extending outside of the vehicle suspension damper and operable. In some embodiments, the remotely operable bypass valve operates in conjunction with other damping mechanisms integrated within the vehicle suspension damper. 
     The following discussion will begin with a general description of a vehicle suspension damper, including the remotely operable bypass valve, in accordance with an embodiment. (See  FIG. 1 ) The discussion continues with a detailed description of the remotely operable bypass valve, in accordance with an embodiment. (See  FIG. 2 ) 
     As used herein, the terms “down”, “up”, “down-ward”, “upward”, “lower”, “upper” and other direction references are relative and are used for reference only. 
     Example Vehicle Suspension Damper with Remotely Operable Bypass Valve 
       FIG. 1  illustrates a vehicle suspension damper  100  with a remotely operable bypass valve  102 , in accordance with an embodiment. The vehicle suspension damper  100  includes a cylinder  120  having an interior  124 , a first end  132 , a second end  106  and defining an axis  136 . The vehicle suspension damper  100  further includes a piston rod  142  and a piston  130 . The piston  130  is movably mounted within the cylinder  120  for moving between the first end  132  and the second end  106 . A bypass cylinder  154  surrounds the cylinder  120  and defines a cylindrical bypass channel  156 . The adjustable bypass port  152 , when open, fluidly couples the interior  124  of the cylinder  120  and the cylindrical bypass channel  156 , permitting some damping fluid to bypass the vented piston  130  when the piston  130  is positioned on the rebound portion  134  side of the adjustable bypass port  152 . 
     In one embodiment, the fluid meters from one side of the piston  130  to the other side by passing through flow paths  126 A and  126 B formed in the piston  130 . In the embodiment shown, shims  128 A and  128 B are used to partially obstruct the flow paths  126 A and  126 B in each direction. By selecting shims  128 A and  128 B having certain desired stiffness characteristics, the damping effects caused by the piston  130  can be increased or decreased and damping rates can be different between the compression and rebound strokes of the piston  130 . For example, shims  128 A are configured to meter rebound flow from the rebound portion  134  of the cylinder  120  to the compression portion  104  of the cylinder  120 . Shims  128 B, on the other hand, are configured to meter compression flow from the compression portion  104  of the cylinder  120  to the rebound portion  134 . In one embodiment, shims  128 B are not included on the rebound portion side, nor is there a compression flow path such as path  126 B, leaving the piston  130  essentially “locked out” in the compression stroke without some means of flow bypass. Note that piston apertures (not shown) may be included in planes other than those shown (e.g. other than apertures used by paths  126 A and  126 B) and further that such apertures may, or may not, be subject to the shims  128 A and  128 B as shown (because for example, the shims  128 A and  128 B may be clover-shaped or have some other non-circular shape). In one embodiment, the piston  130  is solid and all damping flow must traverse a flow bypass and/or communicate with a reservoir. 
     A reservoir  110  is in fluid communication with the cylinder  120  for receiving and supplying damping fluid as the piston rod  142  moves in and out of the cylinder  120 . The reservoir  110  includes a reservoir cylinder  116  in fluid communication with the rebound portion  134  of the damper cylinder  120  via the fluid conduit  108 . The reservoir  110  also includes a floating piston  114  with a volume of gas on a backside  118  (“blind end” side) of it, the gas being compressible as the reservoir cylinder  116 , on the “frontside”  112  fills with damping fluid due to movement of the piston rod  142  and the piston  130  into the damper cylinder  120 . Certain features of reservoir type dampers are shown and described in U.S. Pat. No. 7,374,028, which is incorporated herein, in its entirety, by reference. The upper portion of the piston rod  142  is supplied with a bushing set  138  for connecting to a portion of a vehicle wheel suspension linkage. In another embodiment, not shown, the upper portion of the piston rod  142  (opposite the piston  130 ) may be supplied with an eyelet  140  to be mounted to one part of the vehicle, while the lower part of the vehicle suspension damper  100  is attached to another portion of the vehicle, such as the frame, and moves independently of the first part. A spring member (not shown) is usually mounted to act between the same portions of the vehicle as the vehicle suspension damper. As the piston rod  142  and the piston  130  move into the cylinder  102  (during compression), the damping fluid slows the movement of the two portions of the vehicle relative to each other due, at least in part, to the incompressible fluid moving through the shimmed paths  126 B (past shims  128 B) provided in the piston  130  and/or through an adjustable bypass port  152 , as will be described herein. As the piston rod  142  and the piston  130  move out of the cylinder  120  (during extension or “rebound”), fluid meters again through shimmed paths  126 A and the flow rate and corresponding rebound rate is controlled, at least in part, by the shims  128 A. In  FIG. 1 , the piston  130  is shown at full extension and moving downward in a compression stroke, the movement shown by arrow  122 . 
     Example Remotely Operable Bypass Valve 
       FIG. 2  is an enlarged view showing the remotely operable bypass valve  102 , in accordance with an embodiment. As noted, the adjustable bypass port  152 , when open, fluidly couples the interior  124  of the cylinder  120  with the cylindrical bypass channel  156 , according to an embodiment. The adjustable bypass port  152  permits the damping fluid to travel from a first side of the piston  130  to the other side without traversing shimmed flow paths  126 A and  125 B that may otherwise be traversed in a compression stroke of the vehicle suspension damper  100 . In  FIGS. 1 and 2 , the adjustable bypass port  152  is shown in an “open” position with the flow of fluid through the bypass shown by arrows  144  from a compression side to a rebound side of the piston  130 . 
     In one embodiment, the entry pathway to the adjustable bypass port  152  in the embodiment shown in  FIGS. 1 and 2  is located between the middle and the second end  106  of the cylinder  120 . In one embodiment, as selected by design (e.g., axial location of the entry pathway to the adjustable bypass port  152 ), the adjustable bypass port  152  will not operate after the piston  130  passes the entry to the adjustable bypass port  152  near the end of a compression stroke (or elsewhere in the stroke as desired). In one embodiment, this “position sensitive” feature ensures increased damping will be in effect near the end of the compression stroke to help prevent the piston  130  from approaching a “bottomed out” position (e.g. impact) in the cylinder  120 . The adjustable bypass port  152  and the remotely operable bypass valve  102  of the present embodiments can be used in any combination with the bypass valves shown and described in co-pending U.S. patent application Ser. Nos. 13/010,697. 
     The remotely operable bypass valve  102 , in accordance with embodiments, includes a threaded plug  150 , a rod  148  and a sleeve  146  disposed within the cylindrical bypass channel  156 . In brief, an actuator  158  causes the threaded plug  150  to push the rod  148 . The rod  148  then pushes the sleeve  146 . The sleeve  146  then moves to at least partially cover the adjustable bypass port  152 . More particularly, the actuator  158  is operatively connected to the threaded plug  150  such that the threaded plug  150  can be angularly displaced in the direction of arrow  160  about its longitudinal axis  162  relative to the piston  130  in response to operation of the actuator  158 . The actuator  158  is in the form of a dial, or thumb wheel, secured on the threaded plug  150  at  164 . The actuator  158  extends radially outwardly from the threaded plug  150  such that the threaded plug  150  can be angularly displaced about its longitudinal axis  162  relative to the piston  130  in response to angular displacement of the actuator  158  relative to the piston  130 . Of note, depending on the movement of the actuator  158 , the sleeve  146  may occupy a position within the cylindrical bypass channel  156  such that the sleeve  146  completely blocks the opening of the adjustable bypass port  152 , partially blocks the opening of the adjustable bypass port  152 , or does not block the opening of the adjustable bypass port  152  at all. 
     As can be seen in  FIGS. 1 and 2 , the actuator  158  extends to a position outside of the rest of the vehicle suspension damper  100  so as to enable a user to turn the actuator  158  from outside the rest of the vehicle suspension damper  100 . A turning of the actuator  158  by the user may be referred to as an operation of the actuator  158  by the user. In one embodiment, a detent (not shown) is provided on the actuator  158 . The detent is provided for releasably locking the actuator  158  at a selected angular position relative to the piston  130 . The detent typically includes a ball which cooperates with a helical spring to urge the ball into complementary recesses on the actuator  158 . Certain detent features are described and shown in U.S. Pat. No. 6,360,857, which is incorporated herein, in its entirety, by reference. 
     It should be appreciated that when the actuator  158  is rotated in a reverse direction than that described above and herein, the threaded plug  150  moves in the direction of the arrow  166 . As the threaded plug  150  moves in the direction of the arrow  166 , the rod  148 , and hence also the sleeve  146 , moves in the direction of the arrow  166 , and the adjustable bypass port  152  is at least partially opened. In one embodiment, upon the movement of the threaded plug  150  in the direction of the arrow  166 , the rod  148  and the sleeve  146  moves in the direction of the arrow  166  due to gravity and/or the force applied by the damping fluid against the sleeve  146  from the interior  124  of the cylinder  120  and toward the cylindrical bypass channel  156 . 
     Thus, in addition to the damping features provided by the shims  128 A and  128 B through the flow paths  126 A and  126 B, embodiments enable the metering of damping fluid from the interior  124  of the cylinder  120  to the rebound portion  134  of the vehicle suspension damper  100 , via the remotely operable bypass valve  102  applied to the adjustable bypass port  152 . 
     It should be noted that any of the features disclosed herein may be useful alone or in any suitable combination. While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be implemented without departing from the scope of the invention, and the scope thereof is determined by the claims that follow.