Patent ID: 12227048

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.

Terms

In the following discussion, the term ride height refers to a distance between a portion of a vehicle and the surface across which the vehicle is traversing. For example, one or more suspension components will be coupled with a portion of a wheel(s) (or ski, track, hull, etc.) retaining assembly. In normal operation, the lowest point of the wheel will be in contact with the surface, while a shock assembly and/or other suspension components will be coupled between the wheel retaining assembly and the vehicle (often coupled with a portion of the vehicle frame). The ride height is established by the geometries of the shock assembly and/or other suspension components, the wheel retaining assembly, the wheel and tire profile, and the like.

Often, ride height can be based on one or more of a number of different measurements such as, but not limited to, a distance between a part the vehicle and the ground, a measurement between the top of a tire on the wheel and the wheel well there above, etc.

In the following discussion, the term initial SAG settings or “SAG” refers to a ride height based on the compression of one or more suspension dampers of the suspension system for a vehicle under its normal load configuration (e.g., with a rider/driver and any initial load weight). Once the SAG is established for a vehicle, it will be the designated ride height of the vehicle, until and unless the SAG is changed. Often, SAG is initially established by a manufacturer. For example, an unloaded motorcycle may have an initially assembled suspension ride height ranging from 30-38 inches from ground to saddle. The manufacturer will then set the manufacturer SAG for the vehicle based on a use category, a user weight/height range, the performance envelope, and the like.

In one embodiment, for example, the manufacturer could set the SAG for a 34-inch ride height (a middle of the performance envelope) based on a rider with a weight of 150 lbs. This would mean that unencumbered, the motorcycle would have a seat height that was higher than 34 inches of ride height (such as for example, a seat height of 38 inches). However, when a 150 lb. rider sits on the motorcycle, the suspension would compress and the motorcycle would be at the SAG ride height of 34 inches.

In one embodiment, an owner can modify the SAG to designate a new normal ride height. The SAG could be modified based on a vehicle use purpose, load requirements that are different than the factory load configuration, a change in tire size, a performance adjustment, aesthetics, a height of the user, and the like. For example, if the user wanted to have a lower ride height, they could reduce the SAG to 32 inches. In contrast, if the user wanted a higher ride height, they could increase the SAG to 36 inches.

In one embodiment, the owner could modify one or more suspension components to achieve the SAG. For example, if the rider weighed 180 lbs., when the rider sat on the motorcycle, the ride height would be lower than the 34 inches. As such, the rider would adjust one or more of the suspension components to return the motorcycle to the 34-inch SAG.

In one embodiment, the vehicle will have SAG settings resulting in a pre-established ride height. For example, a truck (side-by-side, car, or the like) may have a pre-established SAG based on an expected load (e.g., a number of passengers, cargo requirements, etc.

Regardless of the vehicle type, in a static properly loaded situation, the ride height of the vehicle should be at or about the SAG. In contrast, while in motion, the ride height will change as the vehicle travels over the surface, and while the suspension system is used to reduce the transference of any input forces received from the surface to the rest of the vehicle, another goal of the suspension system is to continually attempt to return the vehicle to its proper SAG.

However, when additional weight is added to the vehicle, the suspension and/or shock assembly will be compressed, and the vehicle ride height will be less than the SAG.

For example, if a vehicle is loaded with an additional 500 lbs. of cargo in the rear, the extra 500-pound load will cause shock assembly compression (and the like) thereby causing the vehicle to ride lower in the rear. In general, this lower rear ride height, or compressing of the rear suspension, will move the vehicle out of SAG and change the vehicle geometry, e.g., cause a slant upward from rear to front. While the vehicle sensors described herein can identify the out of SAG situation, often, these changes can also be visually identified by a reduction in space between the wheel and the wheel well of the rear wheel as compared to space between the front wheels and wheel wells on the vehicle, or by the angle of the vehicle.

In one embodiment, the additional load will reduce the available operating length of one or more suspension components which can be detrimental to steering and performance characteristics, could cause an unwanted impact between wheel (or wheel suspension) and frame, increase the roughness of the ride, increase suspension stiffness, result in suspension bottom out, loss of control, tire blow out, and the like.

In one embodiment, when the weight is added to the vehicle, if it is not centered, it will not only cause a change in the front or rear SAG (depending upon the load location fore or aft), but will also cause SAG changes that will differ between the left and right side of the vehicle (again depending upon the load location and this time whether the load is heavier on the right or left side of the vehicle centerline).

For example, if the load is in the rear and off-center to the left, the load-modified ride-height of the vehicle will be lopsided. That is, not only will the rear of the vehicle be lower than the front, but the left-side suspension will also be compressed more than the right-side suspension causing the rear left of the vehicle to have a lower ride-height than the other three corners.

Thus, while the entire rear of the vehicle will be out of SAG and therefore riding lower than the front of the vehicle, it will also be lopsided between the left and right sides. Such lopsided suspension characteristics can be extremely deleterious while driving and will often result in a number of issues including, but not limited to: steering problems, suspension bottom out, loss of control, tire blowout, and vehicle rollover.

Overview

The present embodiments utilize a fluid chamber of a spring preload piston assembly of the suspension to allow the ride height to be changed back toward the SAG while on the fly, e.g., while the vehicle is in operation. In one embodiment, the ride height adjustment is automatically made by utilizing a tube in the shaft acting as part of a pump assembly to adjust the amount of fluid within the fluid chamber of the spring preload piston assembly while the suspension is in operation. In general, when fluid is added to the fluid chamber the length of the spring preload piston assembly (and thus the length of the shock assembly) is increased causing an increase in ride height. In contrast, when fluid is removed from the fluid chamber, the length of the spring preload piston assembly (and thus the length of the shock assembly) is reduced causing a decrease in ride height.

In one embodiment, the system can be passive and/or semi-active. For example, in the passive case, the preload system bleeds to a fluid reservoir through tunable orifice. In the semi-active case, a pressure relief valve sets ride height and allows for rapid fluid dump (e.g., providing a large fluid path for the release of fluid from the fluid chamber to reduce the length of the spring preload piston assembly and lowering the vehicle) or system lockout to prevent system bleed down (e.g., maintaining the fluid in the fluid chamber to maintain the length of the spring preload piston assembly, and thus the ride height while the vehicle is parked, stopped, or the like). In one embodiment, the spring preload piston assembly reduces and/or eliminates a possibility of rebound adjustment. In one embodiment, the spring preload piston assembly provides no, or a very small change, to the damping values for different preloads.

Discussion

FIG.1Ais a perspective view of a shock assembly100having an automatic ride height adjustment assembly in accordance with an embodiment. The shock assembly100ofFIG.1Aincludes a helical or coil spring115, a damper housing120with a main chamber and a damping piston coupled with a shaft130(shown in further detail herein), and an external fluid reservoir125having a floating piston and pressurized gas to compensate for a reduction in volume in the main chamber of the shock assembly as the shaft130moves into the damper body.

FIG.1Bis a perspective view of a shock assembly100having an automatic ride height adjustment assembly, external fluid reservoir125, and the associated flow ports therebetween (e.g., flow port161r, flow port161m, flow port162r, and flow port162m), in accordance with an embodiment. In other words,FIG.1Bis an example of one embodiment for fluid communication between the main chamber of the damper and the external fluid reservoir125.

In one embodiment, fluid communication between the main chamber220(as shown at least inFIG.2A) within damper housing120and the external fluid reservoir125may be via a flow channel including an adjustable needle valve. In one embodiment, flow port162mis a rod displacement flow to the base valve. In one embodiment, flow port161mconnects to external fluid reservoir125on an IFP pressure side of a base valve. In one embodiment, flow port161mis configured with an in that uses a low-pressure inlet check and an out that is configured as a high-pressure blowoff.

In one embodiment, two separate hoses are used to connect each of the flow ports, e.g., a first hose to connect flow port161mfrom shock with flow port161rof reservoir and a second hose to connect flow port162mfrom shock with flow port162rof reservoir. In one embodiment, when the external fluid reservoir125is in a piggyback configuration, the porting is internal.

Referring again toFIG.1A, in its basic form, the damper works in conjunction with the coil spring115and controls the speed of movement of the shaft130by metering incompressible fluid from one side of the damper piston (e.g., damping piston210ofFIG.2B) to the other as the damper travels through the main chamber, and additionally metering fluid flow from the main chamber to the external fluid reservoir125, during a compression stroke (and in reverse during the rebound or extension stroke).

In one embodiment, shock assembly100includes spring retaining end267. In one embodiment, spring retaining end267is part of the automatically adjustable ride height assembly. Coil spring115is disposed surrounding the external surface of damper housing120. In the single spring embodiment ofFIG.1A, coil spring115has one end abutting spring retaining end267and another end coupled to a lower flange111.

In one embodiment, shock assembly100also includes upper eyelet105and lower eyelet110for coupling shock assembly100with a suspension system. The upper eyelet105and lower eyelet110are used for mounting one end of the shock assembly to a static portion of the vehicle and the other end of the shock assembly to a dynamic portion of the wheel(s) (or ski, track, hull, etc.) retaining assembly. Although eyelets are shown, it should be appreciated that the mounting systems may be bolts, welds, or the like, the use of eyelets is provided as one embodiment and for purposes of clarity.

Although the eyelets are labeled as upper eyelet105and lower eyelet110, this is providing as one embodiment, and for purposes of defining relative motion of one or more of the components of shock assembly100. Thus, it should be appreciated that in one embodiment, (such as an inverted scenario) the mounting of shock assembly100could be with the upper eyelet105being at a lower point (such as closer to the wheel retaining assembly) while the lower eyelet110would actually be at a higher point on the vehicle than upper eyelet105(e.g., such as at the frame of the vehicle).

In operation, shock assembly100is initially configured with a given preload and overall length (e.g., the established SAG). The overall length is the distance between upper eyelet105and lower eyelet110. The preload is defined by the distance between spring retaining end267and lower flange111, and more specifically the compression of coil spring115. In general, there is more preload when spring retaining end267is moved closer toward lower eyelet110(e.g., compressing coil spring115) and less preload when spring retaining end267is moved closer to upper eyelet105(e.g., increasing the distance between spring retaining end267and lower flange111).

In one embodiment, the automatically adjustable ride height assembly has a minimum length and the resting length of coil spring115applies a pressure to spring retaining end267and lower flange111to maintain a length of shaft130extending from damper housing120and thus the overall length of shock assembly100. When the suspension encounters a bump, shock assembly100enters a compression stage where distance between upper eyelet105and lower eyelet110is reduced as the coil spring115is compressed and the damper piston and shaft130move through the main chamber toward upper eyelet105. After the compression stage, shock assembly100enters a rebound stage where coil spring115provides a pressure on spring retaining end267and lower flange111causing the damper piston and shaft130to move back through the main chamber toward lower eyelet110as shock assembly100returns to its resting size (e.g., its SAG).

It should be appreciated that the automatically adjustable ride height assembly discussed herein could be incorporated into a shock assembly100likeFIG.1A, or in another embodiment, into a shock assembly100with more, fewer, or different components than those shown inFIG.1Asuch as, but not limited to, single spring, multi spring, or air spring shocks, a shock assembly without a remote external fluid reservoir125, and the like.

Moreover, the automatically adjustable ride height capability disclosed herein could be used on one or more shock assemblies of different types, and in an assortment of vehicles such as, but not limited to bicycles, ebikes, motorcycles, all-terrain vehicles (ATV), Side-by-Sides, utility vehicles (UTV), snowmobiles, scooters, recreational off-highway vehicles (ROV), multipurpose off-highway utility vehicles (MOHUV), personal watercrafts (PWC), and the like.

FIG.2Ais a schematic diagram200of shock assembly100with an automatic ride height adjustment assembly shown in accordance with an embodiment. In one embodiment, schematic diagram200includes main chamber220within damper housing120(ofFIG.1A), a tube-in-shaft pump assembly251, and a spring preload piston assembly266.

In one embodiment, main chamber220includes a damping piston210and a compression side221having a base valve pressure P2.

In one embodiment, tube-in-shaft pump assembly251includes a pump tube250with an intake/exhaust port(s)255opening therein. In one embodiment, the pump tube250in conjunction with the damping piston210and shaft130forms the tube-in-shaft pump assembly251when damping piston210and shaft130move during compression and/or rebound.

In one embodiment, spring preload piston assembly266includes tunable orifice(s)265. In one embodiment, the tunable orifice(s)265could be combined for initial tuning. In one embodiment, the tunable orifice(s)265could be separated for initial tuning. In one embodiment, spring preload piston assembly266also includes one or more check valve(s)260.

FIG.2Bis a section view of a shock assembly100based on the schematic diagram200ofFIG.2Ashown in accordance with an embodiment. In one embodiment, shock assembly100includes the components described inFIG.1Aand discloses one or more additional components that are visible in the section view.

In the section view, shock assembly100includes a main chamber220within damper housing120, a damping piston210fixed to shaft130, a pump tube250with an intake/exhaust port(s)255opening therein, a spring preload piston assembly266, and an optional external fluid reservoir125.

In one embodiment, the damping piston210and shaft130are axially movable toward or away from upper eyelet105within main chamber220axially along pump tube250. For example, during compression, the damping piston210and shaft130move axially through main chamber220toward upper eyelet105. In contrast, during rebound, the damping piston210and shaft130move axially through main chamber220away from upper eyelet105.

In one embodiment, the damping piston210is equipped with fluid paths therethrough to permit incompressible fluid within the main chamber220to be metered therethrough during the compression and/or rebound movement. For example, in the compression stroke, at least a portion of fluid within main chamber220utilizes the fluid paths through damping piston210to move from a compression side221of main chamber220to the rebound side222of the main chamber220. In contrast, during a rebound (or extension) stroke, at least a portion of fluid within main chamber220utilizes the fluid paths through damping piston210to move from the rebound side222to the compression side221.

In one embodiment, shock assembly100can also include one or more bypasses that allow fluid to flow around the piston between the compression side221and the rebound side222of the main chamber220during at least a portion of the compression and/or rebound stroke. Additional information regarding the configuration and operation of a bypass is described in U.S. Pat. No. 8,857,580 which is entirely incorporated herein by reference.

In one embodiment where there is an external fluid reservoir125, as shown inFIGS.1B and2B, during at least a portion of the compression and/or rebound stroke fluid can also move through a flow path from the main chamber220into the external fluid reservoir125, thereby causing a reservoir floating piston193to compress a gas chamber194in the external fluid reservoir125. A configuration of a side reservoir, including a floating piston, is described in U.S. Pat. No. 7,374,028 which patent is entirely incorporated herein by reference.

In one embodiment, the ride height adjustment assembly includes components such as, a pump tube250, a spring preload piston assembly266, an intake/exhaust port(s)255, a check valve260, a tunable orifice265, and a relief valve290.

Spring Preload Piston Assembly

With reference still toFIG.2B, in one embodiment, spring preload piston assembly266includes a housing237, a fluid chamber275within the housing237, and a spring retaining end267that is telescopically coupled with housing237. In one embodiment, damper housing120, housing237, and spring retaining end267will fluidly seal a top portion of the spring preload piston assembly266to form a fluid chamber275. In one embodiment, the spring preload piston assembly266may include more or fewer components (such as internal cylinders, seals, O-rings, or the like) to perform the operations described herein.

In one embodiment, the housing237and fluid chamber275within the housing237of spring preload piston assembly266are in a fixed location with respect to damper housing120. In one embodiment, the spring retaining end267is able to move axially along damper housing120as it extends from or retracts into housing237. Thus, as fluid is introduced into the fluid chamber275, the spring retaining end267will be driven toward the lower eyelet110.

For example, as fluid is applied through pump tube250, the fluid will flow into fluid chamber275and ultimately force spring retaining end267to move with respect to housing237in a direction along the axis of damper housing120toward the lower eyelet110. In one embodiment, fluid can enter or leave fluid chamber275via the fluid paths controlled by check valve(s)260and/or tunable orifice(s)265.

In one embodiment, check valve260is a ball spring check valve with flow directions as shown. However, it should be appreciated that check valve260could be another type of valve such as an intelligent quick switch (IQs), a stepper motor adjustable valve, an electronic valve, a gate valve, or the like.

In one embodiment, the check valve260either allows fluid flow in both directions (e.g., open) or only allows fluid to flow in one direction (e.g., closed). In so doing, even if the check valve260is closed, when the shock assembly100is under significant load changes, the fluid flow is only closed in the direction of stopping fluid flow out of fluid chamber275. Thus, in one embodiment, even when the check valve260is closed, the fluid can flow from main chamber220into fluid chamber275.

In one embodiment, when the amount of fluid in fluid chamber275changes, the exposed length15of spring retaining end267also changes thereby increasing or decreasing the length of the spring preload piston assembly266. This increase or decrease in the length of spring preload piston assembly266will result in an increase or decrease in the overall length of shock assembly100resulting in a change to the ride height.

For example, when fluid is pumped into fluid chamber275, spring retaining end267is hydraulically pushed axially along the damper housing120toward lower eyelet110increasing the exposed length15of spring retaining end267. This increase in the exposed length15of spring retaining end267will translate to an increase in the length of the spring preload piston assembly266.

In one embodiment, increasing the length of the spring preload piston assembly266will increase the overall length of shock assembly100resulting in a ride height increase. In one embodiment, since the ride height increase is based on the overall lengthening of shock assembly100, any damping settings and/or the preload of shock assembly100will either not be affected or only be slightly affected. As such, the performance of the shock assembly100will also remain relatively unmodified.

In contrast, when fluid is released from fluid chamber275, spring retaining end267would be pushed by the force of spring115axially along the damper housing120toward upper eyelet105and into the fluid chamber275reducing the exposed length15of spring retaining end267. This decrease in the exposed length15of spring retaining end267will translate to a decrease in the overall length of the spring preload piston assembly266.

In one embodiment, decreasing the length of the spring preload piston assembly266will decrease the overall length of shock assembly100resulting in a ride height reduction. In one embodiment, since the ride height reduction is based on the reduction to the overall length of shock assembly100, any damping settings and/or the preload of shock assembly100will either not be affected or only be slightly affected. As such, the performance of the shock assembly100will also remain relatively unmodified.

Tube-In-Shaft Pump Assembly with Intake/Exhaust Port(s)255

In one embodiment, tube-in-shaft pump assembly251includes a pump tube250and a pumping action provided by the compression and rebound motion of damping piston210and shaft130. In one embodiment, pump tube250is used to pump fluid into fluid chamber275or draws fluid from the main chamber and/or out of fluid chamber275. In one embodiment, the fluid is pumped from the pump tube250into the fluid chamber275via the fluid paths controlled by check valve(s)260and/or tunable orifice(s)265.

In one embodiment, the pump tube250is located along the length of main chamber220. In one embodiment, damping piston210and shaft130will move along the length of pump tube250during rebound and compression strokes. In one embodiment, pump tube250includes at least one intake/exhaust port(s)255. In one embodiment, the intake/exhaust port(s)255is an opening in the pump tube250that is uncovered when the damping piston210and shaft130are below the opening (e.g., closer to lower eyelet110as shown inFIG.2B), and is closed when damping piston210and shaft130are covering thereover (e.g., as shown inFIG.2D).

In one embodiment, the location of the intake/exhaust port(s)255on the pump tube250is set such that when the vehicle is static at the established SAG, the damping piston210will be approximately located thereover.

In one embodiment, based on the SAG defined location of the intake/exhaust port(s)255in the pump tube250with respect to the damping piston210, when the vehicle is in operation, the intake/exhaust port(s)255is approximately half the time covered and half the time uncovered by the damping piston210at SAG ride height. In other words, intake/exhaust port(s)255is covered as the damping piston210and shaft130move toward the upper eyelet105in the compression stroke. In contrast, at some point in the rebound stroke when the damping piston210and shaft130move away from the upper eyelet105the intake/exhaust port(s)255would be uncovered.

In one embodiment, the pump tube250is filled with fluid and will pump the fluid into the fluid chamber275when the intake/exhaust port(s)255is covered during a compression stroke. In contrast, when the intake/exhaust port(s)255is uncovered, such as during a rebound stroke, the fluid will be drawn from the fluid chamber275and back into pump tube250(unless the check valve is closed which is discussed in further detail herein).

Thus, during operation of the vehicle in a normally configured state, e.g., at SAG, the intake/exhaust port(s)255tunes the ride height. If the damping piston210and shaft130are not covering the intake/exhaust port(s)255, fluid is released through the intake/exhaust port(s)255and into the main chamber, if the damping piston210and shaft130are covering the intake/exhaust port(s)255, the fluid is pumped up the pump tube250and into the fluid chamber275. Thus, at SAG, the fluid would be pumped into fluid chamber275during a compression stroke once the damping piston210and shaft130cover the intake/exhaust port(s)255, and would be released from the fluid chamber275during the rebound stroke after the damping piston210and shaft130uncover the intake/exhaust port(s)255.

Riding Low

In one embodiment, when weight is added to the vehicle, the overall shock assembly100length is shortened at least at the location where the weight is added. This reduction in shock assembly100length will result in a lower ride height and the vehicle will no longer be in its SAG configuration.

In one embodiment, the shortening of the shock assembly100length, causes the damping piston210and shaft130to move up the pump tube250closer to the upper eyelet105. As such, in a static situation, the intake/exhaust port(s)255will be covered by the damping piston210and shaft130.

Referring now toFIG.2Ca schematic diagram of the shock assembly riding low in a compression stroke is shown in accordance with an embodiment. InFIG.2C, the fluid volumes are shown for the tube-in-shaft pump assembly251(e.g., P1), the main chamber220compression side (e.g., P2), and the spring preload piston assembly266(e.g., P3).

In one embodiment of the low riding compression stroke (having either high or low shaft speed), the main chamber220compression portion221P2can be low or high. The tube-in-shaft pump assembly251P1will be less than the main chamber220compression portion221P2. The tube-in-shaft pump assembly251P1will be less than or equal to the spring preload piston assembly266P3. In one embodiment, the Vshaft can also be low or high.

FIG.2Dis a section view of shock assembly100illustrating the operation ofFIG.2Cduring a compression stroke, in accordance with an embodiment. In one embodiment, the components ofFIG.2Dare similar to those ofFIG.2B. Therefore, for purposes of clarity the component description will not be repeated, and instead, only the operational differences will be discussed. However, the discussion of the components ofFIG.2Bis incorporated by reference in their entirety.

Referring now toFIG.2Ea schematic diagram of the shock assembly riding low in a rebound stroke is shown in accordance with an embodiment. InFIG.2E, the fluid volumes are shown for the tube-in-shaft pump assembly251(e.g., P1), the main chamber220compression side (e.g., P2), and the spring preload piston assembly266(e.g., P3).

In one embodiment of the low riding rebound stroke (having either high or low shaft speed), the main chamber220compression portion221P2is low. The tube-in-shaft pump assembly251P1will be less than or equal to the main chamber220compression portion221P2. The tube-in-shaft pump assembly251P1will be less than or equal to the spring preload piston assembly266P3. In one embodiment, the Vshaft can also be low or high.

FIG.2Fis a section view of shock assembly100illustrating the operation ofFIG.2Eduring a compression stroke, in accordance with an embodiment. In one embodiment, the components ofFIG.2Fare similar to those ofFIG.2B. Therefore, for purposes of clarity the component description will not be repeated, and instead, only the operational differences will be discussed. However, the discussion of the components ofFIG.2Bis incorporated by reference in their entirety.

In one embodiment, of an example of a low riding scenario, the damping piston210and shaft130are covering the intake/exhaust port(s)255. Therefore, during a compression stroke as shown inFIG.2D, when the damping piston210and shaft130are covering the intake/exhaust port(s)255the fluid is pumped up the pump tube250and into the fluid chamber275. This addition of fluid will cause the fluid chamber275to expand which will cause spring retaining end267to move axially along the damping chamber increasing the exposed length15of spring retaining end267, and therefore, the overall length of spring preload piston assembly266. This increase in the overall length of spring preload piston assembly266would increase the overall length of shock assembly100. In other words, it would basically cause a virtual increase in the length of damper housing120.

With reference now toFIG.2F, since the shock is riding low, during some or all of the rebound stroke, the damping piston210and shaft130would continue to cover the intake/exhaust port(s)255for a majority of even all of the rebound stroke. In the case where the intake/exhaust port(s)255remains covered, in one embodiment, some amount of fluid would be drawn from the fluid chamber275to fill the pump tube250and an additional amount of fluid would be drawn from the main chamber220into the shaft pump tube250as shown by arrow273.

At the next compression (again shown inFIG.2D), the additional fluid that was added to the pump tube250from the main chamber220, in addition to the amount of fluid withdrawn from the fluid chamber275, would be pumped into fluid chamber275, which would further expand the size of fluid chamber275and again cause the spring retaining end267to be hydraulically pushed axial outward once again increasing the overall length of shock assembly100. By lengthening the shock assembly100, the ride height would be increased again.

In one embodiment, the filling and pumping process would continue for each compression and rebound stroke. However, as the ride height increased, the rebound stroke (shown inFIG.2F) would begin to spend more time uncovering the intake/exhaust port(s)255. When the intake/exhaust port(s)255were uncovered by damping piston210and shaft130, an amount of fluid would be released from the pump tube250and therefore from the fluid chamber275.

In one embodiment, the pumping of more fluid into fluid chamber275than the drawing of fluid out of fluid chamber275would continue at an incrementally slower pace until the shock assembly100returned to SAG, at which point the pumping and releasing of fluid from fluid chamber275would again be back to an approximate equilibrium.

In one embodiment, once the SAG height is reached, if the vehicle is stopped or parked, the check valve260may be closed such that the fluid will not leak out of fluid chamber275, and therefore the ride height will not “sink” over time even if the vehicle is parked.

In one embodiment, if the load was too heavy, the maximum size of fluid chamber275could be reached without the shock assembly100reaching SAG height. This could be due to the load causing a significant compression to spring115and thus the shortening of the axial length16. In this example, once the maximum size (or capacity) of fluid chamber275was reached, more fluid would still be being pumped toward fluid chamber275through pump tube250than was being released by fluid chamber275. However, since the size of fluid chamber275is maximized, in one embodiment, any additional fluid that is pumped toward the fluid chamber275would be released through the fluid relief valve290.

In one embodiment, if the shock assembly100were to encounter a significant event causing a large compression, some amount of the fluid pumped through pump tube250would also be dumped through the fluid relief valve290.

Riding High

In one embodiment, when weight is removed from the vehicle, the overall shock assembly100length is increased at least at the location where the weight was removed. This increase in shock assembly100length will result in a higher ride height and the vehicle will no longer be in its SAG configuration.

In one embodiment, the increase of the shock assembly100length, causes the damping piston210and shaft130to move down the pump tube250away from the upper eyelet105. As such, in a static situation, the intake/exhaust port(s)255will be uncovered by the damping piston210and shaft130.

Referring now toFIG.3Aa schematic diagram of the operation of the shock assembly riding high in a compression stroke with a low shaft speed, is shown in accordance with an embodiment. InFIG.3A, the fluid volumes are shown for the tube-in-shaft pump assembly251(e.g., P1), the main chamber220compression portion (e.g., P2), and the spring preload piston assembly266(e.g., P3).

In one embodiment of the riding high compression stroke having a low shaft speed, the main chamber220compression portion P2is low. The tube-in-shaft pump assembly251P1will be equal to the main chamber220compression portion P2. The tube-in-shaft pump assembly251P1will be less than or equal to the spring preload piston assembly266P3. In one embodiment, the Vshaft will also be low.

FIG.3Bis a schematic diagram of the operation of the shock assembly riding high in a compression stroke with a high shaft speed shown in accordance with an embodiment. InFIG.3B, the fluid volumes are shown for the tube-in-shaft pump assembly251(e.g., P1), the main chamber220compression portion (e.g., P2), and the spring preload piston assembly266(e.g., P3).

In one embodiment of the riding high compression stroke having a high shaft speed, the main chamber220compression portion P2is high. The tube-in-shaft pump assembly251P1will be equal to the main chamber220compression portion P2. The tube-in-shaft pump assembly251P1will be less than or equal to the spring preload piston assembly266P3. In one embodiment, the Vshaft will also be high.

In one embodiment, if P2is greater than P3, then P2flows to P3across O1, C1, and C2, O2.

In one embodiment, if P3is greater than P2, then P3flows to P2across C3, O3, and O1.

In one embodiment, the flow state can depend upon the valving, velocity, spring settings, and the like.

FIG.3Cis a section view of shock assembly100illustrating the operation ofFIGS.3A and3Bduring a riding high compression stroke, in accordance with an embodiment. In one embodiment, the components ofFIG.3Care similar to those ofFIG.2B. Therefore, for purposes of clarity the component description will not be repeated, and instead, only the operational differences will be discussed. However, the discussion of the components ofFIG.2Bis incorporated by reference in their entirety.

Referring now toFIG.3Da schematic diagram of the shock assembly riding high in a rebound stroke with either low or high shaft speed is shown in accordance with an embodiment. InFIG.3D, the fluid volumes are shown for the tube-in-shaft pump assembly251(e.g., P1), the main chamber220compression portion (e.g., P2), and the spring preload piston assembly266(e.g., P3).

In one embodiment of the shock assembly riding high in a rebound stroke (having either high or low shaft speed), the main chamber220compression portion P2is low. The tube-in-shaft pump assembly251P1will be less than or equal to the main chamber220compression portion P2. The tube-in-shaft pump assembly251P1will be less than the spring preload piston assembly266P3. In one embodiment, the Vshaft can also be low or high.

FIG.3Eis a section view of shock assembly100illustrating the operation ofFIG.3D, e.g., shock assembly100riding high in a rebound stroke (having either high or low shaft speed) shown in accordance with an embodiment. In one embodiment, the components ofFIG.3Eare similar to those ofFIG.2B. Therefore, for purposes of clarity the component description will not be repeated, and instead, only the operational differences will be discussed. However, the discussion of the components ofFIG.2Bis incorporated by reference in their entirety.

In one embodiment, in an example of a riding high scenario, the intake/exhaust port(s)255are not covered by the damping piston210and shaft130. Therefore, during a compression stroke as shown inFIG.3C, as long as the intake/exhaust port(s)255remained uncovered, the fluid being pumped through pump tube250would flow out of the intake/exhaust port(s)255and into the main chamber. Similarly, the fluid in fluid chamber275would be subjected to the pressure applied by the movement of spring retaining end267moving axially along the damping chamber into the fluid chamber as it is being driven by the spring pressure of spring115. This pressure would cause fluid to drain from fluid chamber275into pump tube250and out of the intake/exhaust port(s)255.

In one embodiment, the movement of spring retaining end267into fluid chamber275will decrease the exposed length15of spring retaining end267, and therefore, the overall length of spring preload piston assembly266. This reduction in the overall length of spring preload piston assembly266would reduce the overall length of shock assembly100.

With reference now toFIG.3E, since the shock is riding high, during the rebound stroke, the intake/exhaust port(s)255would remain uncovered and the pump tube250would continue to draw fluid from fluid chamber275as well as from main chamber220. As such, the fluid chamber275would continue to contract in size as the fluid drained and the spring retaining end267would continue to be pushed into the fluid chamber275by the spring force of spring115reducing the length of spring preload piston assembly266as well as the length of shock assembly100.

At the next compression (again shown inFIG.3C), as long as the intake/exhaust port(s)255remain uncovered, fluid will continue to drain from the fluid chamber275, which would further reduce the size of fluid chamber275and again cause the exposed length15of spring retaining end267to be reduced, thereby continuing to reduce the overall length of shock assembly100. By reducing the length of shock assembly100, the ride height would continue to be reduced.

In one embodiment, process of draining fluid from fluid chamber275would continue for each compression and rebound stroke until the ride height was lowered to a point such that at least a portion of the compression stroke caused the damping piston210and shaft130to begin to cover the intake/exhaust port(s)255. Once the compression stroke began to cover the intake/exhaust port(s)255, the draining of the fluid from fluid chamber275would continue at an incrementally slower pace until the shock assembly100returned to SAG, at which point the pumping and releasing of fluid into and out of fluid chamber275would again be back to an approximate equilibrium.

In one embodiment, the location of fluid chamber intake/exhaust port(s)255on the pump tube250are preset at the factory. In one embodiment, the location of fluid chamber intake/exhaust port(s)255is adjustable along the length of the shaft130to adjust a ride height. In one embodiment, the location of intake/exhaust port(s)255with respect to the pump tube250is changed by replacing the existing pump tube250with a different tube having the intake/exhaust port(s)255in a different location, thereby establishing a new SAG.

In one embodiment, the location of fluid chamber intake/exhaust port(s)255is adjustable along the length of the shaft130to adjust the SAG. For example, the rotation of pump tube250(and/or shaft130, or another control surface) will adjust the location of fluid chamber intake/exhaust port(s)255within the main chamber220. As discussed herein, in one embodiment, intake/exhaust port(s)255is shown in a centralized position for a desired SAG ride height such that the intake/exhaust port(s)255is similarly covered and uncovered by the damping piston210during the compression/rebound suspension cycle.

Thus, if the location of the intake/exhaust port(s)255is moved to a different location, which could be any along pump tube250within main chamber220(preset, user adjustable, automatically adjustable, or the like), the operating range (or amount of time that intake/exhaust port(s)255are not covered or behind damping piston210) would be changed. In so doing, each different location of the intake/exhaust port(s)255would result in different ride height SAG settings.

In one embodiment, relief valve290is configured to provide a fluid dump or rapid release of fluid from fluid chamber275. In one embodiment, the fluid relief valve290provides the fluid to the fluid reservoir when blow-off occurs.

Referring now toFIG.3F, an alternate section view of the shock assembly100with shaft flow to base valve/reservoir is shown in accordance with an embodiment. In one embodiment, the shock assembly100ofFIG.3Fshows the flow from the main chamber220through the base valve393and shows that the operation of the base valve393is not affected by the automatic ride height adjuster.

Tube-In-Shaft Pump Assembly with Spring and Valve Configuration400

With reference now toFIGS.4A-4F, embodiments of a shock assembly with an automatic ride height adjustment are described. InFIGS.4A-4F, a number of the components and operation of the shock assembly were previously disclosed, or similar to those components previously disclosed, in the discussion ofFIGS.1-3Fwhich are incorporated by reference. However, inFIGS.4A-4F, a tube-in-shaft pump assembly251with a spring and valve configuration is used in place of the tube-in-shaft pump assembly251with at least one intake/exhaust port255opening in pump tube250. In one embodiment, pump tube250is located the length of main chamber220.

Thus, the following discussion ofFIGS.4A-4F, will focus on the operational differences when the shock assembly100uses the tube-in-shaft pump assembly251with a spring and valve configuration400. For purposes of clarity, unless otherwise discussed, the remainder of the operation of the shock assembly100and will be similar to that already described inFIGS.1-3F.

In other words, the modification ofFIGS.4A-4Fis directly related to the change from an intake/exhaust port(s)255in pump tube250to a spring and valve configuration400. Thus, the operation of spring preload piston assembly266remains the same.

With reference now toFIG.4A, a schematic diagram401of a shock assembly with automatically adjustable ride height using a tube-in-shaft pump assembly251with the spring and valve configuration400to automatically adjustable ride height assembly in accordance with an embodiment. Schematic diagram401includes a spring preload piston assembly266, pump tube250, preload spring spacer402, preload spring405, valve404, bleed orifice408, low-pressure inlet check valve2601, and fluid relief valve290(e.g., a high-pressure blow-off). Although a number of components are shown and described, in one embodiment, there may be more or fewer components. Thus, the use of the above components is an example of one embodiment.

In one embodiment, valve404is a poppet, a spool, or the like.

Referring now toFIG.4B, a section view of a portion of a shock assembly with an automatically adjustable ride height assembly using a tube-in-shaft pump assembly251with the spring and valve configuration400is shown in accordance with an embodiment. In one embodiment, tube-in-shaft pump assembly251with a spring and valve configuration400includes a number of the components described inFIGS.1-3F.

In one embodiment, the tube-in-shaft pump assembly251with a spring and valve configuration400includes components such as spring preload piston assembly266, pump tube250, a preload spring spacer402, a preload spring405, a valve404, a bleed orifice408, filter409, low-pressure inlet check valve2601, high-pressure return path253h. In one embodiment, the tube-in-shaft pump assembly251with a spring and valve configuration400is used to fill and/or empty the fluid chamber275of spring preload piston assembly266.

In one embodiment, spring preload piston assembly266extends or contracts spring retaining end267to adjust the length of the spring preload piston assembly266thereby increasing or decreasing the length of shock assembly100to automatically adjust/return the ride height to SAG. In one embodiment, pump tube250forces fluid into the fluid chamber275when the shock is compressed and guides the preload spring405and preload spring spacer402.

In one embodiment, preload spring spacer402is used to tune or adjust the point in the damping piston210stroke when the preload spring405engages the valve404. In general, the preload spring405engages valve404when it provides enough force to close valve404. Otherwise, if the preload spring405does not provide enough force to close valve404, valve404will be disengaged.

In one embodiment, valve404controls the flow of fluid from the high-pressure return path253h. When engaged by the preload spring405, fluid is pumped through the high-pressure checked supply path412into the fluid chamber275. However, when engaged, valve404will not allow fluid to leave the fluid chamber275via the high-pressure return path253h.

When valve404is disengaged, fluid can still be pumped through the high-pressure checked supply path412into the fluid chamber275. However, and in contrast to the engaged popped, when valve404is disengaged, the fluid in fluid chamber275is also allowed leave via the high-pressure return path253h.

In one embodiment, the bleed orifice408includes filter409and is used to control the rate at which the fluid bleeds out of the fluid chamber275, reducing preload, and lowering the vehicle. In one embodiment, the fluid of fluid chamber275can bleed through the bleed orifice408regardless of the position of valve404(e.g., engaged or disengaged).

In one embodiment, low-pressure inlet check valve2601allows fluid to flow into the pump tube250. In one embodiment, the fluid flow from low-pressure inlet check valve2601goes to the main shock body. In one embodiment, low-pressure inlet check valve2601is provided after a base valve so the supply will always be low-pressure.

In one embodiment, fluid flow is shown between pump tube250and fluid chamber275of spring preload piston assembly266. In one embodiment, low-pressure inlet check valve2601is a ball spring check valve. However, it should be appreciated that low-pressure inlet check valve2601could be another type of valve such as an intelligent quick switch (IQs) such as a stepper motor adjustable valve, an electronic valve, a gate valve, or the like.

In one embodiment, the low-pressure inlet2601either allows fluid flow in both directions (e.g., open) or only allows fluid to flow in one direction (e.g., closed). In so doing, even if the low-pressure inlet check valve2601is closed, when the shock assembly100is under significant load changes, the fluid flow is only closed in the direction of stopping fluid flow out of fluid chamber275of spring preload piston assembly266. Thus, in one embodiment, even when the check valve260is closed, the fluid can be pumped into fluid chamber275of spring preload piston assembly266.

In one embodiment, fluid relief valve290is a high-pressure blow-off. In one embodiment, as described herein, when the coil spring115is at full preload capacity (or a compression event that surpasses an event threshold occurs), there is a stop to prevent the spring preload cylinder from moving too far.

In one embodiment, fluid relief valve290is configured to provide a fluid dump or rapid release of fluid from fluid chamber275, such as, for example, to prevent extreme pressures in system. In one embodiment, the fluid relief valve290provides the fluid released from fluid chamber275to the external fluid reservoir125when blow-off occurs.

In one embodiment, filter409is shown upstream of the bleed orifice408to filter large debris such as burrs from machining, poorly cleaned parts, assembly debris, etc. In one embodiment, the filter409is large enough to filter particles without restricting fluid flow. For example, in a bleed orifice408with an inner diameter of 0.0020 of an inch, in one embodiment, the filter409would be less than 0.0010 inch. As such, the filter409will stop larger particles that would plug the bleed orifice408, but it will allow smaller contaminants to pass through. In so doing, the filter409will not become clogged with smaller particles.

Referring now toFIGS.4C-4F, are section views of the shock assembly100riding in different configurations during compression and rebound are shown in accordance with an embodiment. In one embodiment, shock assembly100ofFIGS.4C-4Finclude the tube-in-shaft pump assembly251with a spring and valve configuration400, the spring preload piston assembly266, main chamber220within damper housing120, damping piston210fixed to shaft130, coil spring115, and upper eyelet105.

In one embodiment, the damping piston210and shaft130are axially movable toward or away from upper eyelet105within main chamber220axially along pump tube250. In one embodiment, the movement of damping piston210and shaft130will also include the movement of preload spring spacer402. For example, during compression, damping piston210, shaft130, and preload spring spacer402move axially through main chamber220toward upper eyelet105. In contrast, during rebound, damping piston210, shaft130, and preload spring spacer402move axially through main chamber220away from upper eyelet105. In one embodiment there is an external fluid reservoir125.

In one embodiment, tube-in-shaft pump assembly251with a spring and valve configuration400uses the compression and rebound motion of damping piston210, shaft130, and preload spring spacer402to pump fluid from the main chamber220(or another fluid chamber such as a low-pressure reservoir fluid chamber) into fluid chamber275and/or bleed (or withdraw) fluid from fluid chamber275and back to the main chamber220(or another fluid chamber such as a low-pressure reservoir fluid chamber). In one embodiment, the fluid is pumped from the pump tube250into the fluid chamber275via the fluid flow path(s)253(such as high-pressure return path253h) controlled by check valve(s)260(such as the check valve on low-pressure inlet check valve2601), tunable orifice(s)265, and the like.

In one embodiment, the pump tube250is filled with fluid and will pump the fluid into the fluid chamber275when the valve404is engaged e.g., when it is opened by the spring force of preload spring405. In contrast, when the valve404is disengaged, such as during a rebound stroke, the fluid will be drawn from the fluid chamber275and back into pump tube250(unless the check valve is closed as described herein).

In one embodiment, the SAG for shock assembly100is set by adjusting the location of the preload spring spacer402to tune the point in the damping piston210stroke when the preload spring405engages the valve404. Thus, adjusting the preload spring spacer402will establish the SAG, in the same way that adjusting the location of intake/exhaust port(s)255opening set the SAG.

In one embodiment, the location of the preload spring spacer402along the pump tube250and in relation to the preload spring405and the spring force it exerts on valve404are preset at the factory. In one embodiment, the location of preload spring spacer402is adjustable along the length of the pump tube250within shaft130to adjust a ride height by a user or a tuner at a store, a bike shop, at home, etc. In one embodiment, the location of preload spring spacer402with regard to the preload spring405and the spring force it exerts on valve404is changed by replacing the existing preload spring spacer402with another preload spring spacer402of a different length, thereby establishing a new SAG.

In one embodiment, the location of preload spring spacer402is user adjustable along the length of the shaft130to adjust the SAG. For example, the rotation of pump tube250(and/or shaft130, or another control surface) will adjust the location of preload spring spacer402within pump tube250which will modify the relationship with the preload spring405and the spring force it exerts on valve404.

In one embodiment, once the desired SAG ride height is established. The preload spring spacer402will be located such that when in SAG, the preload spring405will exert an amount of spring force on valve404that will not be engaged. However, as the damping piston210and shaft130move during the compression and rebound suspension cycles that spring force will change.

In general, while the vehicle is in SAG ride height, on a compression stroke the preload spring spacer402will push against the preload spring405such that the additional amount of spring force applied to valve404will engage valve404. When valve404is engaged, fluid will be added to fluid chamber275.

In contrast, while the vehicle is in SAG ride height, on a rebound stroke the preload spring spacer402will release an amount of pressure applied to the preload spring405such that the reduced amount of spring force from preload spring405will disengage valve404. When valve404is disengaged, fluid will be bled from fluid chamber275.

Thus, when the vehicle is in SAG ride height, the tube-in-shaft pump assembly251with a spring and valve configuration400will maintain the SAG ride height by pumping fluid into and releasing fluid from fluid chamber275.

In one embodiment, if a change in the SAG ride height was desired, the location of preload spring spacer402would be adjusted (e.g., user adjusted, manually adjusted, automatically adjusted, or the like), which would change the SAG ride height location of damping piston210within main chamber220and similarly adjust the force applied to preload spring405and thus, the spring force it exerts on valve404. In so doing, an adjustment in the preload spring spacer402would result in a different ride height SAG setting.

In one embodiment, preload spring405could be replaced with a preload spring405having a different length to modify the desired SAG ride height. In one embodiment, preload spring405could be replaced with a preload spring405having a different spring constant to modify the desired SAG ride height. In one embodiment, preload spring405could be replaced with a preload spring405having a different length and a different spring constant to modify the desired SAG ride height.

In one embodiment, one, some, or all of the location of preload spring spacer402, the length of preload spring spacer402, the length of preload spring405, and/or the spring constant of preload spring405could be adjusted to change the SAG ride height.

In one embodiment, the pump tube250of the tube-in-shaft pump assembly251may include an interior tube that utilizes the spring and valve configuration400, and an exterior tube (e.g., a larger pump tube surrounding a smaller pump tube) that has the intake/exhaust port(s)255opening such that the tube-in-shaft pump assembly251would utilize both pumping schemes described herein to achieve and maintain the vehicles SAG ride height.

For example, if the suspension of the vehicle had a large range of motion or if the shock assembly100were for a heavy-duty vehicle (e.g., a semi-truck, heavy towing vehicle, mining truck, etc.) and therefore larger in girth and/or overall length than a shock assembly100for a normal vehicle (e.g., a side-by-side, motorcycle, pick-up truck, etc.), the amount of fluid that could be pushed into fluid chamber275would be large enough that the operation of both of the disclosed tube-in-shaft pump assembly251configurations would provide a more efficient capability to maintain the SAG ride height as the vehicle is loaded and/or unloaded.

Riding Low

As stated herein,FIG.4Cis a section view of the shock assembly100having the tube-in-shaft pump assembly251with a spring and valve configuration400riding low in a compression stroke in accordance with an embodiment. In contrast,FIG.4Dis a section view of the shock assembly100having the tube-in-shaft pump assembly251with a spring and valve configuration400riding low in a rebound stroke in accordance with an embodiment.

As described herein, riding low refers to a suspension ride height that is lower than the SAG. In one example, the vehicle may be riding low when weight is added to the vehicle, the shock assembly100length is shortened at least at the location where the weight is added. This reduction in shock assembly100length will result in a vehicle ride height that is lower than its SAG configuration.

In one embodiment of the low riding compression stroke, the fluid volumes and pressures are similar to those described inFIGS.2C and2E. In one embodiment, the shortening of the shock assembly100length, causes damping piston210, shaft130, and preload spring spacer402to move up the pump tube250closer to the upper eyelet105. As such, in a static situation, the valve404will be engaged by preload spring405.

In one embodiment, during a compression stroke as shown inFIG.4C, when the valve404is engaged the fluid is pumped up the pump tube250and into the fluid chamber275via the high-pressure checked supply path412. In other words, pump tube250can pump fluid through the high-pressure checked supply path412even when preload spring405is engaging valve404. In one embodiment, a majority of the fluid flows through the flow paths indicated by the light flow arrows ofFIG.4C. In one embodiment, a small amount of pump flow is lost across the open bleed orifice408as shown by the dotted arrow. However, as long as valve404is engaged, high-pressure return path253hwill be closed and fluid will not be able to leave fluid chamber275via the closed high-pressure return path253h.

In one embodiment, the additional fluid pumped into fluid chamber275will cause fluid chamber275to expand causing spring retaining end267to move axially along the damping chamber increasing the exposed length15of spring retaining end267. This will increase the overall length of spring preload piston assembly266which will increase the overall length of shock assembly100and cause the ride height to begin to rise.

With reference now toFIG.4D, since the shock is riding low, during some or all of the rebound stroke, the valve404will remain engaged for a majority of even all of the rebound stroke. In one embodiment, while the valve404is engaged, high-pressure return path253hwill be closed and fluid will not be able to leave fluid chamber275via the closed high-pressure return path253h. In one embodiment, the fluid that refills the pump tube will flow through the low-pressure inlet check valve2601(as shown by the light arrow).

At the next compression (again shown inFIG.4C), the fluid that was added to the pump tube250during rebound would be pumped into fluid chamber275via the high-pressure checked supply path412, which would again expand the size of fluid chamber275and again cause the spring retaining end267to be hydraulically pushed axial outward increasing the overall length of shock assembly100and the ride height.

In one embodiment, the fluid chamber275filling process will continue for each compression and rebound stroke until the ride height begins to approach SAG, at which time, a portion of the rebound stroke (shown inFIG.4D) causes the preload spring405pressure on valve404to drop below the pressure on valve404from the fluid in high-pressure return path253h. When that transition does occur, valve404will disengage. When valve404is disengaged, an amount of fluid would be released from fluid chamber275through the high-pressure return path253h. After that point, such as during the next compression stroke, the valve404would be engaged and then during part of the rebound stroke the valve404would be disengaged.

However, the valve404would likely spend a larger amount of time engaged than disengaged which would mean the pumping of more fluid into fluid chamber275than the removal of fluid from fluid chamber275would continue, although at a slower pace, until the shock assembly100returned to SAG, at which point the pumping and releasing of fluid from fluid chamber275would again be back to an approximate equilibrium.

In one embodiment, once the SAG height is reached, if the vehicle is stopped or parked, the preload spring405force on valve404would keep valve404engaged keeping the high-pressure return path253hclosed. As such, the ride height will not “sink” over time even if the vehicle is stopped at a red light, or parked for an amount of time.

In one embodiment, once the SAG height is reached, if the vehicle is stopped or parked, in a semi-active embodiment, the check valve260(and or fluid relief valve290) can also be closed such that the fluid will not leak out of fluid chamber275, and therefore the ride height will not “sink” over time even if the vehicle is stopped at a red light, or parked for an amount of time.

In one embodiment, if the load was too heavy, the maximum size of fluid chamber275could be reached without the shock assembly100reaching SAG height. This could be due to the load causing a significant compression to coil spring115and thus the shortening of the axial length16. In this example, once the maximum size (or capacity) of fluid chamber275was reached, more fluid would still be being pumped from pump tube250through the high-pressure checked supply path412toward fluid chamber275. However, since the size of fluid chamber275is maximized, in one embodiment, any additional fluid that is pumped from pump tube250through the high-pressure checked supply path412toward the fluid chamber275would be released through the fluid relief valve290.

In one embodiment, if the shock assembly100were to encounter a significant event causing a large compression, some amount of the fluid pumped from pump tube250through the high-pressure checked supply path412would also be dumped through the fluid relief valve290.

Riding High

As stated herein,FIG.4Eis a section view of the shock assembly100having the tube-in-shaft pump assembly251with a spring and valve configuration400riding high in a compression stroke in accordance with an embodiment. In contrast,FIG.4Fis a section view of the shock assembly100having the tube-in-shaft pump assembly251with a spring and valve configuration400riding high in a rebound stroke in accordance with an embodiment.

In one embodiment, when weight is removed from the vehicle, the shock assembly100length is increased at least at the location where the weight was removed. In one embodiment, the increase of the shock assembly100length, causes damping piston210, shaft130, and preload spring spacer402to move down the pump tube250away from the upper eyelet105. This increase in shock assembly100length will result in a vehicle ride height that is higher than its SAG configuration.

In one embodiment of the riding high compression stroke, the fluid volumes and pressures are similar to those described inFIGS.3A and3B. In one embodiment of the riding high rebound stroke, the fluid volumes and pressures are similar to those described inFIG.3D.

In one embodiment, in an example of a riding high scenario, the valve404is disengaged due to the lack of spring force on valve404from preload spring405. Since the valve404is disengaged, the fluid in fluid chamber275is able to flow out of the fluid chamber275through the open high-pressure return path253h. This will allow the spring retaining end267to begin to retract into fluid chamber275which will decrease the exposed length15of spring retaining end267, and therefore reduce the overall length of spring preload piston assembly266. Reducing the overall length of spring preload piston assembly266will reduce the overall length of shock assembly100and cause the vehicle ride height to lower.

During a compression stroke as shown inFIG.4E, the fluid being pumped through pump tube250would flow into the high-pressure checked supply path412. However, as long as valve404remains disengaged, the fluid in fluid chamber275will continue to flow out of fluid chamber275through the open high-pressure return path253h. In one embodiment, some small amount of pump flow would also be lost across the open bleed orifice408.

In one embodiment, fluid will leave fluid chamber275as it will be subjected to the pressure applied by the movement of spring retaining end267moving axially along the damping chamber into the fluid chamber as it is being driven by the spring pressure of coil spring115. This pressure would cause fluid to drain from fluid chamber275.

In one embodiment, the movement of spring retaining end267into fluid chamber275will decrease the exposed length15of spring retaining end267, and therefore, reduce the overall length of spring preload piston assembly266and the overall length of shock assembly100.

With reference now toFIG.4F, since the shock assembly100is riding high, during the rebound stroke, valve404would remain disengaged and the fluid that was pumped into high-pressure checked supply path412during the compression stroke will not be restricted by valve404and will return to refill the pump tube250. At the same time, fluid would continue to drain from fluid chamber275via high-pressure return path253h. Therefore, in one embodiment, during rebound the fluid chamber275would continue to contract in size as the fluid drained from fluid chamber275and the spring retaining end267would continue to be pushed into the fluid chamber275by the spring force of coil spring115reducing the length of spring preload piston assembly266as well as the length of shock assembly100.

At the next compression (again shown inFIG.4E), as long as valve404remains disengaged, fluid will continue to be pumped into high-pressure checked supply path412and drain from the fluid chamber275via high-pressure return path253h. At the next rebound, the fluid in high-pressure checked supply path412would return to refill the pump tube250, and additional fluid would continue to leave fluid chamber275via high-pressure return path253hwhich would further reduce the size of fluid chamber275and again cause the exposed length15of spring retaining end267to be reduced, thereby continuing to reduce the ride height.

In one embodiment, the draining of fluid from fluid chamber275would continue for each compression and rebound stroke until the ride height was lowered to a point approaching SAG such that at least a portion of the compression stroke caused the preload spring spacer402to begin to engage valve404. Once the compression stroke began to engage valve404, the draining of the fluid from fluid chamber275via high-pressure return path253hwould stop when the valve404was engaged, but begin again when valve404was disengaged (such as during a portion of the rebound stroke). As such, the reduction of fluid from fluid chamber275would continue at an incrementally slower pace until the shock assembly100returned to SAG, at which point the pumping and releasing of fluid into and out of fluid chamber275would again be back to an approximate equilibrium.

In one embodiment, fluid relief valve290is configured to provide a fluid dump or rapid release of fluid from fluid chamber275. In one embodiment, the fluid relief valve290provides the fluid to the fluid reservoir when blow-off occurs.

With reference now toFIG.4G, a graph of spring force versus travel485for a shock assembly with and without an automatic ride height adjustment due to an additional load, shown in accordance with an embodiment.

In one embodiment, the graph of spring force versus travel485shows an example of the increased spring preload force vs shock travel for both preload cases. In one embodiment, as shown in the graph of spring force versus travel485, the spring preload system can add an additional 500 lb of force per shock for added payload. In one embodiment, as shown in the graph of spring force versus travel485the automatic ride height adjustment system has 2″ of preload capability, and vehicle uses a 250 lb/in spring.

FIG.4His a graph of spring/valve opening forces490for the shock assembly with and without an automatic ride height adjustment due to an additional load, shown in accordance with an embodiment.

In one embodiment, the graph of spring/valve opening forces490is an example showing the forces required to close the valve tuned for an engagement shock stroke of 2″ as indicated by the vertical engaged line at the 2″ mark on the graph of spring/valve opening forces490. The line plotted in diamonds shows the spring force acting on the valve. In one embodiment, this must exceed the force acting on the valve by the hydraulic preload chamber pressure in order to pump the system up to add preload; e.g., (Force=Chamber Pressure*Valve Seat Area).

The line plotted in circles shows the force acting on the valve when there is no preload on the spring. The line plotted in triangles shows the force acting on the valve when the system is at full preload.

Mark499indicates when the preload spring405would begin to be engaged. At about 3.5 inches of shock stroke, if there is no spring preload on the system, it will start to pump-up the spring preload piston assembly266. In contrast, if there is full-preload on the system, it will attempt to start pumping up the spring preload piston assembly266at about 4 inches of shock stroke.

In one embodiment, the speed of the pump-up is a tuning parameter that can be set during the OE tuning cycle. In one embodiment, depending upon the speed of pump-up desired by the customer, parameters such as valve preload, valve seat diameter, the pump tube diameter, and the like, can be tuned, adjusted, modified, or replaced to obtain the desired pump-up speed.

For example, in one embodiment, any, some, or all of the orifice sizes in the flow path for the automatic ride height adjustment assembly (including the fluid relief valve290, intake/exhaust port(s)255, valve455, and the like) are manually adjustable. For example, the orifice size(s) could be adjusted by a party accessing an exterior adjustment feature to manually adjust the one or more orifice sizes.

In one embodiment, any, some, or all of the orifice sizes and/or the flow paths for the automatic ride height adjustment assembly (including the fluid relief valve290, intake/exhaust port(s)255, valve455, and the like) are automatically adjustable such as via the use of an active valve550.

For example, little orifices/flow channels are good for small velocity inputs into the shock assembly such as in a passenger car driving down a paved road. However, when the inputs are higher velocity inputs (like those suspension events that occur in an offroad environment and/or offroad vehicle), the size of the orifices need to be larger to reduce the increased damping that would otherwise occur in the little orifices. Thus, the ability to adjust the orifice size allows the adjustment to be made depending upon the environment.

Moreover, by using adjustable orifice sizes, check valves, and the like, the ride height will not “sink” over time even if the vehicle is parked. That is, the fluid in the fluid chamber will be held in the chamber without bleed.

In one embodiment, the automatic ride height adjustment assembly can include one of, a combination of, or all of the different available adjustment options. That is, check valve260open or closing, moving the location of the intake/exhaust port(s)255, the fluid chamber275including a check valve260, the blow-off setting of relief valve290, the size of tunable orifice265is adjustable, etc. In so doing, the adjustments to the operational characteristics of the automatic ride height adjustment assembly can be almost infinite. Further, the ability to automate the movement and/or opening of the different components and valves can provide significant adjustment capability that can be provided at different times within a single span of a ride. Moreover, if an extreme event is realized, the excess pressure in fluid chamber275could be automatically reduced using check valve260and/or relief valve290.

Thus, embodiments provide the ability to self-level a vehicle. That is, to automatically return to and maintain the ride height (e.g., the SAG for the vehicle). For example, if weight is added to the cargo bed the ride height of vehicle will drop. To counteract this the passive ride height system will begin pumping fluid to a hydraulic spring preload system when the shock is cycled until SAG ride height is achieved. Thus, embodiments provide the ability to automatically return to and maintain the SAG ride height of a vehicle.

In general, pump tube250provides a fluid flow path between a rebound portion of the damper and fluid chamber275. In one embodiment, the pump tube250is located within shaft130, that is, it is internal to the shaft130. In another embodiment, pump tube250is partially (or completely) external of the shaft130.

In one embodiment, valve404is a check valve. However, it should be appreciated that valve404could be another type of valve such as an intelligent quick switch (IQs), a stepper motor adjustable valve, an electronic valve, a gate valve, or the like.

In one embodiment, the preload spring spacer402in the pump tube250is located with respect to the preload spring405such that the pressure on preload spring405will keep valve404closed at the proper ride height or SAG.

In one embodiment, a vehicle will have SAG settings resulting in a pre-established ride height. In a static situation, the ride height of the vehicle is at or about the SAG. When in motion, the ride height will change as the vehicle travels over the surface, and while the suspension system is used to reduce the transference of any input forces received from the surface to the rest of the vehicle, another goal of the suspension system is to return the vehicle to its SAG.

In another example, a rider is utilizing a snowmobile and has the suspension ride height set up for a single rider (e.g., 140 lbs.). At some point, the rider invites a passenger along to also enjoy the sled ride. However, with two riders on the sled, the weight is now (200 lbs.) and the suspension ride height (e.g., the established SAG for the vehicle) is lowered due to the compression of shock assembly100.

In one embodiment, by utilizing the automatic ride height adjustment assembly, the system would adjust the fluid volume in fluid chamber275as described herein to increase the overall length of the shock assembly and return the snowmobile to the established SAG for the vehicle. Thus, this would return the suspension ride height to a relatively similar SAG as it was set for the solo rider with little or no changes to any damper settings, preload, or the like.

In one embodiment, when the passenger gets off of the sled, the ride height adjustment assembly would again adjust the fluid volume in fluid chamber275(as described herein), thereby returning the ride height to the established SAG. This time, for example, the amount of fluid in fluid chamber275would be reduced so that the overall length of shock assembly100would be reduced until it reached the appropriate length for the SAG. Thus, here again the suspension ride height would be returned to an initial SAG, and again with little or no changes to any damper settings, preload adjustments, or the like.

In another example, if the additional weight added to the vehicle resulted in a 10 mm reduction in height from the established SAG, during suspension operation as described above, the axial length of spring preload piston assembly266would be automatically increased until the ride height was returned to the established SAG. As such, the return to SAG would be automatic and would make little or no changes to any damper settings, preload, or the like of shock assembly100.

Moreover, when the additional weight was removed, the ride height would become higher than the established SAG, during suspension operation as described above, the axial length of spring preload piston assembly266would be reduced until the SAG was achieved. As such, the ride height would be automatically return to the proper SAG with little or no changes to any damper settings, preload, or the like of shock assembly100.

Therefore, if a vehicle is loaded with an additional 500 lbs. of cargo in the rear, the extra 500-pound load will cause shock assembly compression (and the like) thereby causing the vehicle to ride lower in the rear. In general, this lower rear ride height, or compressing of the rear suspension, will move the vehicle out of SAG and change the vehicle geometry, e.g., cause a slant upward from rear to front. While the vehicle sensors described herein can identify the out of SAG situation, often, these changes can also be visually identified by a reduction in space between the wheel and the wheel well of the rear wheel as compared to space between the front wheels and wheel wells on the vehicle, or by the angle of the vehicle.

In one embodiment, the additional load will reduce the available operating length of one or more suspension components which can be detrimental to steering and performance characteristics, could cause an unwanted impact between wheel (or wheel suspension) and frame, increase the roughness of the ride, increase suspension stiffness, result in suspension bottom out, loss of control, tire blow out, and the like.

In one embodiment, when the weight is added to the vehicle, if it is not centered, it will not only cause a change in the front or rear SAG (depending upon the load location fore or aft), but will also cause SAG changes that will differ between the left and right side of the vehicle (again depending upon the load location and this time whether the load is heavier on the right or left side of the vehicle centerline).

For example, if the load is in the rear and off-center to the left, the load-modified ride-height of the vehicle will be lopsided. That is, not only will the rear of the vehicle be lower than the front, but the left-side suspension will also be compressed more than the right-side suspension causing the rear left of the vehicle to have a lower ride-height than the other three corners.

Thus, while the entire rear of the vehicle will be out of SAG and therefore riding lower than the front of the vehicle, it will also be lopsided between the left and right sides. Such lopsided suspension characteristics can be extremely deleterious while driving and will often result in a number of issues including, but not limited to: steering problems, suspension bottom out, loss of control, tire blowout, and vehicle rollover.

However, by utilizing the automatic ride height adjustment shock assembly disclosed herein, the suspension system would adjust the fluid volume in the fluid chambers of each shock assembly in the suspension system to return the vehicle to the established SAG. As such, the lopsided suspension characteristics would be resolved, and the vehicle would be in a significantly safer suspension configuration that does not have (or has to a much lesser degree) any number of the above issues including, but not limited to: steering problems, suspension bottom out, loss of control, tire blowout, and vehicle rollover.

In one embodiment, one or more of the valves within shock assembly100are active valves as described in further detail inFIGS.5A-6. In one embodiment, one or more of the valves within shock assembly100are non-active valves, e.g., a manual valve that may be adjustable but is not electronically adjustable.

Example Active Valve

Referring now toFIG.5A, an enlarged view of an active valve550is shown in accordance with an embodiment.

In the following discussion, the term “active”, as used when referring to a valve or damping component, means adjustable, manipulatable, etc., during typical operation of the valve. For example, an active valve can have its operation changed to thereby alter a corresponding damping characteristic from a “soft” damping setting to a “firm” damping setting by, for example, adjusting a switch in a passenger compartment of a vehicle. Additionally, it will be understood that in some embodiments, an active valve may also be configured to automatically adjust its operation, and corresponding damping characteristics, based upon, for example, operational information pertaining to the vehicle and/or the suspension with which the valve is used. Similarly, it will be understood that in some embodiments, an active valve may be configured to automatically adjust its operation, and corresponding damping characteristics, to provide damping based upon received user input settings (e.g., a user-selected “comfort” setting, a user-selected “sport” setting, and the like). Additionally, in many instances, an “active” valve is adjusted or manipulated electronically (e.g., using a powered solenoid, or the like) to alter the operation or characteristics of a valve and/or other component. As a result, in the field of suspension components and valves, the terms “active”, “electronic”, “electronically controlled”, and the like, are often used interchangeably.

In the following discussion, the term “manual” as used when referring to a valve or damping component means manually adjustable, physically manipulatable, etc., without requiring disassembly of the valve, damping component, or suspension damper which includes the valve or damping component. In some instances, the manual adjustment or physical manipulation of the valve, damping component, or suspension damper, which includes the valve or damping component, occurs when the valve is in use. For example, a manual valve may be adjusted to change its operation to alter a corresponding damping characteristic from a “soft” damping setting to a “firm” damping setting by, for example, manually rotating a knob, pushing or pulling a lever, physically manipulating an air pressure control feature, manually operating a cable assembly, physically engaging a hydraulic unit, and the like. For purposes of the present discussion, such instances of manual adjustment/physical manipulation of the valve or component can occur before, during, and/or after “typical operation of the vehicle”.

It should further be understood that a vehicle suspension may also be referred to using one or more of the terms “passive”, “active”, “semi-active” or “adaptive”. As is typically used in the suspension art, the term “active suspension” refers to a vehicle suspension which controls the vertical movement of the wheels relative to vehicle. Moreover, “active suspensions” are conventionally defined as either a “pure active suspension” or a “semi-active suspension” (a “semi-active suspension” is also sometimes referred to as an “adaptive suspension”). In a conventional “pure active suspension”, a motive source such as, for example, an actuator, is used to move (e.g. raise or lower) a wheel with respect to the vehicle. In a “semi-active suspension”, no motive force/actuator is employed to adjust move (e.g. raise or lower) a wheel with respect to the vehicle. Rather, in a “semi-active suspension”, the characteristics of the suspension (e.g. the firmness of the suspension) are altered during typical use to accommodate conditions of the terrain and/or the vehicle. Additionally, the term “passive suspension”, refers to a vehicle suspension in which the characteristics of the suspension are not changeable during typical use, and no motive force/actuator is employed to adjust move (e.g. raise or lower) a wheel with respect to the vehicle. As such, it will be understood that an “active valve”, as defined above, is well suited for use in a “pure active suspension” or a “semi-active suspension”.

AlthoughFIG.5Ashows the active valve550in a closed position (e.g. during a rebound stroke of the damper), the following discussion also includes the opening of active valve550. Active valve550includes a valve body704housing a movable piston705which is sealed within the body. The piston705includes a sealed chamber707adjacent an annularly-shaped piston surface706at a first end thereof. The chamber707and annular piston surface706are in fluid communication with a port725accessed via opening726. Two additional fluid communication points are provided in the body including an inlet orifice702and an outlet orifice703for fluid passing through the active valve550.

Extending from a first end of the piston705is a shaft710having a cone-shaped nipple712(other shapes such as spherical or flat, with corresponding seats, will also work suitably well) disposed on an end thereof. The nipple712is telescopically mounted relative to, and movable on, the shaft710and is biased toward an extended position due to a spring715coaxially mounted on the shaft710between the nipple712and the piston705. Due to the spring biasing, the nipple712normally seats itself against a seat717formed in an interior of the valve body704.

As shown, the nipple712is seated against seat717due to the force of the spring715and absent an opposite force from fluid entering the active valve550along orifice702. As nipple712telescopes out, a gap720is formed between the end of the shaft710and an interior of nipple712. A vent721is provided to relieve any pressure formed in the gap. With a fluid path through the active valve550(from703to702) closed, fluid communication is substantially shut off from the rebound side of the cylinder into the valve body (and hence to the compression side) and its “dead-end” path is shown by arrow719.

In one embodiment, there is a manual pre-load adjustment on the spring715permitting a user to hand-load or un-load the spring using a threaded member708that transmits motion of the piston705towards and away from the conical member, thereby changing the compression on the spring715.

Also shown inFIG.5Ais a plurality of valve operating cylinders751,752,753. In one embodiment, the cylinders each include a predetermined volume of fluid755that is selectively movable in and out of each cylindrical body through the action of a separate corresponding piston765and rod766for each cylindrical body. A fluid path770runs between each cylinder and port725of the valve body where annular piston surface706is exposed to the fluid.

Because each cylinder has a specific volume of substantially incompressible fluid and because the volume of the sealed chamber707adjacent the annular piston surface706is known, the fluid contents of each cylinder can be used, individually, sequentially or simultaneously to move the piston a specific distance, thereby effecting the damping characteristics of the system in a relatively predetermined and precise way.

While the cylinders751-753can be operated in any fashion, in the embodiment shown each piston765and rod766is individually operated by a solenoid775and each solenoid, in turn, is operable from a remote location of the vehicle, like a cab of a motor vehicle or even the handlebar area of a motor or bicycle (not shown). Electrical power to the solenoids775is available from an existing power source of a vehicle or is supplied from its own source, such as on-board batteries. Because the cylinders may be operated by battery or other electric power or even manually (e.g. by syringe type plunger), there is no requirement that a so-equipped suspension rely on any pressurized vehicle hydraulic system (e.g. steering, brakes) for operation. Further, because of the fixed volume interaction with the bottom out valve there is no issue involved in stepping from hydraulic system pressure to desired suspension bottom out operating pressure.

In one embodiment, e.g., when active valve550is in the damping-open position, fluid flow through orifice702provides adequate force on the nipple712to urge it backwards, at least partially loading the spring715and creating a fluid flow path from the orifice702into and through orifice703.

The characteristics of the spring715are typically chosen to permit active valve550(e.g. nipple712) to open at a predetermined pressure, with a predetermined amount of control pressure applied to port725. For a given spring715, higher control pressure at port725will result in higher pressure required to open the active valve550and correspondingly higher damping resistance in orifice702. In one embodiment, the control pressure at port725is raised high enough to effectively “lock” the active valve closed resulting in a substantially rigid compression damper (particularly true when a solid damping piston is also used).

In one embodiment, the valve is open in both directions when the nipple712is “topped out” against valve body704. In another embodiment however, when the valve piston705is abutted or “topped out” against valve body704the spring715and relative dimensions of the active valve550still allow for the nipple712to engage the valve seat717thereby closing the valve. In such embodiment backflow from the rebound side to the compression side is always substantially closed and cracking pressure from flow along orifice702is determined by the pre-compression in the spring715. In such embodiment, additional fluid pressure may be added to the inlet through port725to increase the cracking pressure for flow along orifice702and thereby increase compression damping. It is generally noteworthy that while the descriptions herein often relate to compression damping and rebound shut off, some or all of the channels (or channel) on a given suspension unit may be configured to allow rebound damping and shut off or impede compression damping.

While the examples illustrated relate to manual operation and automated operation based upon specific parameters, in various embodiments, active valve550can be remotely-operated and can be used in a variety of ways with many different driving and road variables and/or utilized at any point during use of a vehicle. In one example, active valve550is controlled based upon vehicle speed in conjunction with the angular location of the vehicle's steering wheel. In this manner, by sensing the steering wheel turn severity (angle of rotation), additional damping (by adjusting the corresponding size of the opening of orifice702by causing nipple712to open, close, or partially close orifice702) can be applied to one shock assembly or one set of vehicle shock assemblies on one side of the vehicle (suitable for example to mitigate cornering roll) in the event of a sharp turn at a relatively high speed.

In another example, a transducer, such as an accelerometer, measures other aspects of the vehicle's suspension system, like axle force and/or moments applied to various parts of the vehicle, like steering tie rods, and directs change to position of active valve550(and corresponding change to the working size of the opening of orifice702by causing nipple712to open, close, or partially close orifice702) in response thereto. In another example, active valve550is controlled at least in part by a pressure transducer measuring pressure in a vehicle tire and adding damping characteristics to some or all of the wheels (by adjusting the working size of the opening of orifice702by causing nipple712to open, close, or partially close orifice702) in the event of, for example, an increased or decreased pressure reading. In one embodiment, active valve550is controlled in response to braking pressure (as measured, for example, by a brake pedal (or lever) sensor or brake fluid pressure sensor or accelerometer). In still another example, a parameter might include a gyroscopic mechanism that monitors vehicle trajectory and identifies a “spin-out” or other loss of control condition and adds and/or reduces damping to some or all of the vehicle's dampers (by adjusting the working size of the opening of orifice702by causing nipple712to open, close, or partially close orifice702chambers) in the event of a loss of control to help the operator of the vehicle to regain control.

For example, active valve550, when open, permits a first flow rate of the fluid through orifice702. In contrast, when active valve550is partially closed, a second flow rate of the fluid though orifice702occurs. The second flow rate is less than the first flow rate but greater than no flow rate. When active valve550is completely closed, the flow rate of the fluid though orifice702is statistically zero.

In one embodiment, instead of (or in addition to) restricting the flow through orifice702, active valve550can vary a flow rate through an inlet or outlet passage within the active valve550, itself. See, as an example, the electronic valve of FIGS. 2-4 of U.S. Pat. No. 9,353,818 which is incorporated by reference herein, in its entirety, as further example of different types of “electronic” or “active” valves). Thus, the active valve550, can be used to meter the fluid (e.g., working fluid) flow (e.g., control the rate of working fluid flow) with/or without adjusting the flow rate through orifice702.

Due to the active valve550arrangement, a relatively small solenoid (using relatively low amounts of power) can generate relatively large damping forces. Furthermore, due to incompressible fluid inside the shock assembly100, damping occurs as the distance between nipple712and orifice702is reduced. The result is a controllable damping rate. Certain active valve features are described and shown in U.S. Pat. Nos. 9,120,362; 8,627,932; 8,857,580; 9,033,122; and 9,239,090 which are incorporated herein, in their entirety, by reference.

It should be appreciated that when the body704rotates in a reverse direction than that described above and herein, the nipple712moves away from orifice702providing at least a partially opened fluid path.

FIG.5Bis a schematic diagram showing a control arrangement500for a remotely-operated active valve550. As illustrated, a signal line502runs from a switch504to a solenoid506. Thereafter, the solenoid506converts electrical energy into mechanical movement and rotates body704within active valve550, In one embodiment, the rotation of body704causes an indexing ring consisting of two opposing, outwardly spring-biased balls to rotate among indentions formed on an inside diameter of a lock ring.

As the body704rotates, nipple712at an opposite end of the valve is advanced or withdrawn from an opening in orifice702. For example, the body704is rotationally engaged with the nipple712. A male hex member extends from an end of the body704into a female hex profile bore formed in the nipple712. Such engagement transmits rotation from the body704to the nipple712while allowing axial displacement of the nipple712relative to the body704. Therefore, while the body does not axially move upon rotation, the threaded nipple712interacts with mating threads formed on an inside diameter of the bore to transmit axial motion, resulting from rotation and based on the pitch of the threads, of the nipple712towards or away from an orifice702, between a closed position, a partially open position, and a fully or completely open position.

Adjusting the opening of orifice702modifies the flowrate of the fluid through active valve550thereby varying the stiffness of a corresponding shock assembly100. WhileFIG.5Bis simplified and involves control of a single active valve550, it will be understood that any number of active valves corresponding to any number of fluid channels (e.g., bypass channels, external fluid reservoir channels, bottom out channels, etc.) for a corresponding number of vehicle suspension dampers could be used alone or in combination. That is, one or more active valves could be operated simultaneously or separately depending upon needs in a vehicular suspension system. For example, a suspension damper could have one, a combination of, or each of an active valve(s): for a bottom out control, an internal bypass, for an external bypass, for a fluid conduit to the external fluid reservoir125, etc. In other words, anywhere there is a fluid flow path within a shock assembly100, an active valve could be used. Moreover, the active valve could be alone or used in combination with other active valves at other fluid flow paths to automate one or more of the damping performance characteristics of the shock assembly. Moreover, additional switches could permit individual operation of separate active bottom out valves.

In addition to, or in lieu of, the simple, switch-operated remote arrangement ofFIG.5B, the remotely-operable active valve550can be operated automatically based upon one or more driving conditions, and/or automatically or manually utilized at any point during use of a vehicle.FIG.6shows a schematic diagram of a control system600based upon any or all of vehicle speed, damper rod speed, and damper rod position. One embodiment of the arrangement ofFIG.6is designed to automatically increase damping in a shock assembly in the event a damper rod reaches a certain velocity in its travel towards the bottom end of a damper at a predetermined speed of the vehicle. In one embodiment, the control system600adds damping (and control) in the event of rapid operation (e.g. high rod velocity) of the shock assembly100to avoid a bottoming out of the damper rod as well as a loss of control that can accompany rapid compression of a shock assembly with a relative long amount of travel. In one embodiment, the control system600adds damping (e.g., adjusts the size of the opening of orifice702by causing nipple712to open, close, or partially close orifice702) in the event that the rod velocity in compression is relatively low but the rod progresses past a certain point in the travel.

Such configuration aids in stabilizing the vehicle against excessive low-rate suspension movement events such as cornering roll, braking and acceleration yaw and pitch and “g-out.”

FIG.6illustrates, for example, a control system600including three variables: wheel speed, corresponding to the speed of a vehicle component (measured by wheel speed transducer604), piston rod position (measured by piston rod position transducer606), and piston rod velocity (measured by piston rod velocity transducer608). Any or all of the variables shown may be considered by logic unit602in controlling the solenoids or other motive sources coupled to active valve550for changing the working size of the opening of orifice702by causing nipple712to open, close, or partially close orifice702. Any other suitable vehicle operation variable may be used in addition to or in lieu of the variables discussed herein, such as, for example, piston rod compression strain, eyelet strain, vehicle mounted accelerometer (or tilt/inclinometer) data or any other suitable vehicle or component performance data.

In one embodiment, the piston's position within the damping chamber is determined using an accelerometer to sense modal resonance of the suspension damper. Such resonance will change depending on the position of the piston and an on-board processor (computer) is calibrated to correlate resonance with axial position. In one embodiment, a suitable proximity sensor or linear coil transducer or other electro-magnetic transducer is incorporated in the damping chamber to provide a sensor to monitor the position and/or speed of the piston (and suitable magnetic tag) with respect to a housing of the suspension damper.

In one embodiment, the magnetic transducer includes a waveguide and a magnet, such as a doughnut (toroidal) magnet that is joined to the cylinder and oriented such that the magnetic field generated by the magnet passes through the rod and the waveguide. Electric pulses are applied to the waveguide from a pulse generator that provides a stream of electric pulses, each of which is also provided to a signal processing circuit for timing purposes. When the electric pulse is applied to the waveguide, a magnetic field is formed surrounding the waveguide. Interaction of this field with the magnetic field from the magnet causes a torsional strain wave pulse to be launched in the waveguide in both directions away from the magnet. A coil assembly and sensing tape is joined to the waveguide. The strain wave causes a dynamic effect in the permeability of the sensing tape which is biased with a permanent magnetic field by the magnet. The dynamic effect in the magnetic field of the coil assembly due to the strain wave pulse, results in an output signal from the coil assembly that is provided to the signal processing circuit along signal lines.

By comparing the time of application of a particular electric pulse and a time of return of a sonic torsional strain wave pulse back along the waveguide, the signal processing circuit can calculate a distance of the magnet from the coil assembly or the relative velocity between the waveguide and the magnet. The signal processing circuit provides an output signal, which is digital or analog, proportional to the calculated distance and/or velocity. A transducer-operated arrangement for measuring piston rod speed and velocity is described in U.S. Pat. No. 5,952,823 and that patent is incorporated by reference herein in its entirety.

While transducers located at the suspension damper measure piston rod velocity (piston rod velocity transducer608), and piston rod position (piston rod position transducer606), a separate wheel speed transducer604for sensing the rotational speed of a wheel about an axle includes housing fixed to the axle and containing therein, for example, two permanent magnets. In one embodiment, the magnets are arranged such that an elongated pole piece commonly abuts first surfaces of each of the magnets, such surfaces being of like polarity. Two inductive coils having flux-conductive cores axially passing therethrough abut each of the magnets on second surfaces thereof, the second surfaces of the magnets again being of like polarity with respect to each other and of opposite polarity with respect to the first surfaces. Wheel speed transducers are described in U.S. Pat. No. 3,986,118 which is incorporated herein by reference in its entirety.

In one embodiment, as illustrated inFIG.6, the logic unit602with user-definable settings receives inputs from piston rod position transducer606, piston rod velocity transducer608, as well as wheel speed transducer604. Logic unit602is user-programmable and, depending on the needs of the operator, logic unit602records the variables and, then, if certain criteria are met, logic unit602sends its own signal to active valve550(e.g., the logic unit602is an activation signal provider) to cause active valve550to move into the desired state (e.g., adjust the flow rate by adjusting the distance between nipple712and orifice702). Thereafter, the condition, state or position of active valve550is relayed back to logic unit602via an active valve monitor or the like.

In one embodiment, logic unit602shown inFIG.6assumes a single active valve550corresponding to a single orifice702of a single shock assembly100, but logic unit602is usable with any number of active valves or groups of active valves corresponding to any number of orifices, or groups of orifices. For instance, the suspension dampers on one side of the vehicle can be acted upon while the vehicles other suspension dampers remain unaffected.

It should be appreciated that the automatically adjustable ride height capability discussed herein could be incorporated into a shock assembly likeFIG.1A, or in another embodiment, into a shock assembly with more, fewer, or different components than those shown inFIG.1A. Moreover, the automatically adjustable ride height capability disclosed herein could be used on one or more shock assemblies across an assortment of vehicles such as, but not limited to a bicycle, motorcycle, ATV, jet ski, car, snow mobile, side-by-side, and the like.

The foregoing Description of Embodiments is not intended to be exhaustive or to limit the embodiments to the precise form described. Instead, example embodiments in this Description of Embodiments have been presented in order to enable persons of skill in the art to make and use embodiments of the described subject matter. Moreover, various embodiments have been described in various combinations. However, any two or more embodiments could be combined. Although some embodiments have been described in a language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed by way of illustration and as example forms of implementing the claims and their equivalents.