Adjustable internal bypass

[0001] This application is a continuation application of and claims priority to and benefit of co-pending U.S. patent application Ser. No. 14/487,529, filed on Sep. 16, 2014 entitled, “ADJUSTABLE INTERNAL BYPASS” by John Marking, assigned to the assignee of the present application, and incorporated herein, in its entirety, by reference.

[0002] 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.

[0003] 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.

[0004] 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.

[0005] 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.

[0009] The drawings referred to in this description should be understood as not being drawn to scale except if specifically noted.

[0010] 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.

[0011] 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.

[0012] 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)

[0013] As used herein, the terms “down”, “up”, “down-ward”, “upward”, “lower”, “upper” and other direction references are relative and are used for reference only.

[0014] 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.

[0015] In one embodiment, the fluid meters from one side of the piston 130 to the other side by passing through flow paths 126A and 126B formed in the piston 130. In the embodiment shown, shims 128A and 128B are used to partially obstruct the flow paths 126A and 126B in each direction. By selecting shims 128A and 128B 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 128A 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 128B, 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 128B are not included on the rebound portion side, nor is there a compression flow path such as path 126B, 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 126A and 126B) and further that such apertures may, or may not, be subject to the shims 128A and 128B as shown (because for example, the shims 128A and 128B 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.

[0016] 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 126B (past shims 128B) 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 126A and the flow rate and corresponding rebound rate is controlled, at least in part, by the shims 128A. In FIG. 1, the piston 130 is shown at full extension and moving downward in a compression stroke, the movement shown by arrow 122.

[0017] 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 126A and 125B 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] Thus, in addition to the damping features provided by the shims 128A and 128B through the flow paths 126A and 126B, 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.

[0023] 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.