Patent Description:
Embodiments of the invention generally relate to methods and apparatus for use in vehicle suspension. Particular embodiments of the invention relate to a shock assembly, to a vehicle comprising the shock assembly, and to a method for automatically adjusting a ride height of a shock assembly.

Vehicle suspension systems typically include a spring component or components and a damping component or components that form a suspension to provide for a comfortable ride, enhance performance of a vehicle, and the like. For example, a hard suspension is important for a performance scenario while a soft suspension is better at providing a comfortable ride. However, in operation, the hardness or softness will change with the amount of weight being suspended. For example, a <NUM> (<NUM>-pound) rider on a motorcycle may have a shock assembly set to a softer setting to provide a comfortable ride. However, when a <NUM> (<NUM>-pound) rider rides the same motorcycle with the same setting, the shock assembly would likely have a much shorter length of available travel. Similarly, if the shock assembly was set up for the heavier rider, it would be in an extremely hard setting if the vehicle was used by the lighter rider. Thus, the heavier rider would need to change components of (or the entirety of) the shock assembly to obtain performance characteristics similar to the lighter rider and vice-versa.

<CIT> discloses a vehicle height adjustment apparatus including: a front wheel-side change unit that can change a front wheel relative position, which is a relative position between a body of a vehicle and a front wheel of the vehicle; a rear wheel-side change unit that can change a rear wheel relative position, which is a relative position between the body and a rear wheel of the vehicle; and a control unit that controls the front wheel-side change unit and the rear wheel-side change unit so as to change the front wheel and the rear wheel relative positions to adjust a vehicle height, which is a height of the body of the vehicle, and the control unit increases the vehicle height while maintaining a ratio of a displacement of the front wheel relative position to a displacement of the rear wheel relative position within a predetermined range.

According to the present invention there is provided a shock assembly comprising:.

Further features are set out in claims <NUM> to <NUM>, and <NUM>, to which attention is hereby directed.

According to another aspect of the present invention there is provided a shock assembly comprising:.

Further features are set out in claims <NUM> to <NUM> to which attention is hereby directed.

According to the present invention there is provided a vehicle comprising a shock assembly as set out above.

In an embodiment the vehicle may be an ebike. In an embodiment the vehicle may be a motorcycle. In an embodiment the vehicle may be an all-terrain vehicle (ATV). In an embodiment the vehicle may be a Side-by-Side. In an embodiment the vehicle may be a utility vehicle (UTV). In an embodiment the vehicle may be a snowmobile. In an embodiment the vehicle may be a scooter. In an embodiment the vehicle may be a recreational off-highway vehicle (ROV). In an embodiment the vehicle may be a multipurpose off-highway utility vehicle (MOHUV). In an embodiment the vehicle may be a personal watercraft (PWC).

According to another aspect of the present invention there is provided a method for automatically adjusting a ride height of a shock assembly, said method comprising:.

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

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.

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 <NUM>-<NUM> (<NUM>-<NUM> 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 <NUM> (<NUM>-inch) ride height (a middle of the performance envelope) based on a rider with a weight of <NUM> (150lbs).

This would mean that unencumbered, the motorcycle would have a seat height that was higher than <NUM> (<NUM>-inches) of ride height (such as for example, a seat height of <NUM> (<NUM> inches)).

However, when a <NUM> (1501b. ) rider sits on the motorcycle, the suspension would compress and the motorcycle would be at the SAG ride height of <NUM> (<NUM> 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 <NUM> (<NUM> inches).

In contrast, if the user wanted a higher ride height, they could increase the SAG to <NUM> (<NUM> inches).

In one embodiment, the owner could modify one or more suspension components to achieve the SAG. For example, if the rider weighed <NUM> (1801bs. ), when the rider sat on the motorcycle, the ride height would be lower than the <NUM> (<NUM> inches).

As such, the rider would adjust one or more of the suspension components to return the motorcycle to the <NUM> (<NUM>-inch).

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 <NUM> (500lbs. ) of cargo in the rear, the extra 2224N (<NUM>-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.

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.

<FIG> is a perspective view of a shock assembly <NUM> having an automatic ride height adjustment assembly in accordance with an embodiment. The shock assembly <NUM> of <FIG> includes a helical or coil spring <NUM>, a damper housing <NUM> with a main chamber and a damping piston coupled with a shaft <NUM> (shown in further detail herein), and an external fluid reservoir <NUM> having a floating piston and pressurized gas to compensate for a reduction in volume in the main chamber of the shock assembly as the shaft <NUM> moves into the damper body.

<FIG> is a perspective view of a shock assembly <NUM> having an automatic ride height adjustment assembly, external fluid reservoir <NUM>, and the associated flow ports therebetween (e.g., flow port 161r, flow port <NUM>, flow port 162r, and flow port <NUM>), in accordance with an embodiment. In other words, <FIG> is an example of one embodiment for fluid communication between the main chamber of the damper and the external fluid reservoir <NUM>.

In one embodiment, fluid communication between the main chamber <NUM> (as shown at least in <FIG>) within damper housing <NUM> and the external fluid reservoir <NUM> may be via a flow channel including an adjustable needle valve. In one embodiment, flow port <NUM> is a rod displacement flow to the base valve. In one embodiment, flow port <NUM> connects to external fluid reservoir <NUM> on an IFP pressure side of a base valve. In one embodiment, flow port <NUM> is 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 port <NUM> from shock with flow port 161r of reservoir and a second hose to connect flow port <NUM> from shock with flow port 162r of reservoir. In one embodiment, when the external fluid reservoir <NUM> is in a piggyback configuration, the porting is internal.

Referring again to <FIG>, in its basic form, the damper works in conjunction with the coil spring <NUM> and controls the speed of movement of the shaft <NUM> by metering incompressible fluid from one side of the damper piston (e.g., damping piston <NUM> of <FIG>) to the other as the damper travels through the main chamber, and additionally metering fluid flow from the main chamber to the external fluid reservoir <NUM>, during a compression stroke (and in reverse during the rebound or extension stroke).

In one embodiment, shock assembly <NUM> includes spring retaining end <NUM>. In one embodiment, spring retaining end <NUM> is part of the automatically adjustable ride height assembly. Coil spring <NUM> is disposed surrounding the external surface of damper housing <NUM>. In the single spring embodiment of <FIG>, coil spring <NUM> has one end abutting spring retaining end <NUM> and another end coupled to a lower flange <NUM>.

In one embodiment, shock assembly <NUM> also includes upper eyelet <NUM> and lower eyelet <NUM> for coupling shock assembly <NUM> with a suspension system. The upper eyelet <NUM> and lower eyelet <NUM> are 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 eyelet <NUM> and lower eyelet <NUM>, this is providing as one embodiment, and for purposes of defining relative motion of one or more of the components of shock assembly <NUM>. Thus, it should be appreciated that in one embodiment, (such as an inverted scenario) the mounting of shock assembly <NUM> could be with the upper eyelet <NUM> being at a lower point (such as closer to the wheel retaining assembly) while the lower eyelet <NUM> would actually be at a higher point on the vehicle than upper eyelet <NUM> (e.g., such as at the frame of the vehicle).

In operation, shock assembly <NUM> is initially configured with a given preload and overall length (e.g., the established SAG). The overall length is the distance between upper eyelet <NUM> and lower eyelet <NUM>. The preload is defined by the distance between spring retaining end <NUM> and lower flange <NUM>, and more specifically the compression of coil spring <NUM>. In general, there is more preload when spring retaining end <NUM> is moved closer toward lower eyelet <NUM> (e.g., compressing coil spring <NUM>) and less preload when spring retaining end <NUM> is moved closer to upper eyelet <NUM> (e.g., increasing the distance between spring retaining end <NUM> and lower flange <NUM>).

In one embodiment, the automatically adjustable ride height assembly has a minimum length and the resting length of coil spring <NUM> applies a pressure to spring retaining end <NUM> and lower flange <NUM> to maintain a length of shaft <NUM> extending from damper housing <NUM> and thus the overall length of shock assembly <NUM>. When the suspension encounters a bump, shock assembly <NUM> enters a compression stage where distance between upper eyelet <NUM> and lower eyelet <NUM> is reduced as the coil spring <NUM> is compressed and the damper piston and shaft <NUM> move through the main chamber toward upper eyelet <NUM>. After the compression stage, shock assembly <NUM> enters a rebound stage where coil spring <NUM> provides a pressure on spring retaining end <NUM> and lower flange <NUM> causing the damper piston and shaft <NUM> to move back through the main chamber toward lower eyelet <NUM> as shock assembly <NUM> returns 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 assembly <NUM> like <FIG>, or in another embodiment, into a shock assembly <NUM> with more, fewer, or different components than those shown in <FIG> such as, but not limited to, single spring, multi spring, or air spring shocks, a shock assembly without a remote external fluid reservoir <NUM>, 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> is a schematic diagram <NUM> of shock assembly <NUM> with an automatic ride height adjustment assembly shown in accordance with an embodiment. In one embodiment, schematic diagram <NUM> includes main chamber <NUM> within damper housing <NUM> (of <FIG>), a tube-in-shaft pump assembly <NUM>, and a spring preload piston assembly <NUM>.

In one embodiment, main chamber <NUM> includes a damping piston <NUM> and a compression side <NUM> having a base valve pressure P2.

In one embodiment, tube-in-shaft pump assembly <NUM> includes a pump tube <NUM> with an intake/exhaust port(s) <NUM> opening therein. In one embodiment, the pump tube <NUM> in conjunction with the damping piston <NUM> and shaft <NUM> forms the tube-in-shaft pump assembly <NUM> when damping piston <NUM> and shaft <NUM> move during compression and/or rebound.

In one embodiment, spring preload piston assembly <NUM> includes tunable orifice(s) <NUM>. In one embodiment, the tunable orifice(s) <NUM> could be combined for initial tuning. In one embodiment, the tunable orifice(s) <NUM> could be separated for initial tuning. In one embodiment, spring preload piston assembly <NUM> also includes one or more check valve(s) <NUM>.

<FIG> is a section view of a shock assembly <NUM> based on the schematic diagram <NUM> of <FIG> shown in accordance with an embodiment. In one embodiment, shock assembly <NUM> includes the components described in <FIG> and discloses one or more additional components that are visible in the section view.

In the section view, shock assembly <NUM> includes a main chamber <NUM> within damper housing <NUM>, a damping piston <NUM> fixed to shaft <NUM>, a pump tube <NUM> with an intake/exhaust port(s) <NUM> opening therein, a spring preload piston assembly <NUM>, and an optional external fluid reservoir <NUM>.

In one embodiment, the damping piston <NUM> and shaft <NUM> are axially movable toward or away from upper eyelet <NUM> within main chamber <NUM> axially along pump tube <NUM>. For example, during compression, the damping piston <NUM> and shaft <NUM> move axially through main chamber <NUM> toward upper eyelet <NUM>. In contrast, during rebound, the damping piston <NUM> and shaft <NUM> move axially through main chamber <NUM> away from upper eyelet <NUM>.

In one embodiment, the damping piston <NUM> is equipped with fluid paths therethrough to permit incompressible fluid within the main chamber <NUM> to be metered therethrough during the compression and/or rebound movement. For example, in the compression stroke, at least a portion of fluid within main chamber <NUM> utilizes the fluid paths through damping piston <NUM> to move from a compression side <NUM> of main chamber <NUM> to the rebound side <NUM> of the main chamber <NUM>. In contrast, during a rebound (or extension) stroke, at least a portion of fluid within main chamber <NUM> utilizes the fluid paths through damping piston <NUM> to move from the rebound side <NUM> to the compression side <NUM>.

In one embodiment, shock assembly <NUM> can also include one or more bypasses that allow fluid to flow around the piston between the compression side <NUM> and the rebound side <NUM> of the main chamber <NUM> during at least a portion of the compression and/or rebound stroke. Additional information regarding the configuration and operation of a bypass is described in <CIT>.

In one embodiment where there is an external fluid reservoir <NUM>, as shown in <FIG> and <FIG>, during at least a portion of the compression and/or rebound stroke fluid can also move through a flow path from the main chamber <NUM> into the external fluid reservoir <NUM>, thereby causing a reservoir floating piston <NUM> to compress a gas chamber <NUM> in the external fluid reservoir <NUM>. A configuration of a side reservoir, including a floating piston, is described in <CIT>.

In one embodiment, the ride height adjustment assembly includes components such as, a pump tube <NUM>, a spring preload piston assembly <NUM>, an intake/exhaust port(s) <NUM>, a check valve <NUM>, a tunable orifice <NUM>, and a relief valve <NUM>.

With reference still to <FIG>, in one embodiment, spring preload piston assembly <NUM> includes a housing <NUM>, a fluid chamber <NUM> within the housing <NUM>, and a spring retaining end <NUM> that is telescopically coupled with housing <NUM>. In one embodiment, damper housing <NUM>, housing <NUM>, and spring retaining end <NUM> will fluidly seal a top portion of the spring preload piston assembly <NUM> to form a fluid chamber <NUM>. In one embodiment, the spring preload piston assembly <NUM> may 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 housing <NUM> and fluid chamber <NUM> within the housing <NUM> of spring preload piston assembly <NUM> are in a fixed location with respect to damper housing <NUM>. In one embodiment, the spring retaining end <NUM> is able to move axially along damper housing <NUM> as it extends from or retracts into housing <NUM>. Thus, as fluid is introduced into the fluid chamber <NUM>, the spring retaining end <NUM> will be driven toward the lower eyelet <NUM>.

For example, as fluid is applied through pump tube <NUM>, the fluid will flow into fluid chamber <NUM> and ultimately force spring retaining end <NUM> to move with respect to housing <NUM> in a direction along the axis of damper housing <NUM> toward the lower eyelet <NUM>. In one embodiment, fluid can enter or leave fluid chamber <NUM> via the fluid paths controlled by check valve(s) <NUM> and/or tunable orifice(s) <NUM>.

In one embodiment, check valve <NUM> is a ball spring check valve with flow directions as shown. However, it should be appreciated that check valve <NUM> could 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 valve <NUM> either 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 valve <NUM> is closed, when the shock assembly <NUM> is under significant load changes, the fluid flow is only closed in the direction of stopping fluid flow out of fluid chamber <NUM>. Thus, in one embodiment, even when the check valve <NUM> is closed, the fluid can flow from main chamber <NUM> into fluid chamber <NUM>.

In one embodiment, when the amount of fluid in fluid chamber <NUM> changes, the exposed length <NUM> of spring retaining end <NUM> also changes thereby increasing or decreasing the length of the spring preload piston assembly <NUM>. This increase or decrease in the length of spring preload piston assembly <NUM> will result in an increase or decrease in the overall length of shock assembly <NUM> resulting in a change to the ride height.

For example, when fluid is pumped into fluid chamber <NUM>, spring retaining end <NUM> is hydraulically pushed axially along the damper housing <NUM> toward lower eyelet <NUM> increasing the exposed length <NUM> of spring retaining end <NUM>. This increase in the exposed length <NUM> of spring retaining end <NUM> will translate to an increase in the length of the spring preload piston assembly <NUM>.

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

In contrast, when fluid is released from fluid chamber <NUM>, spring retaining end <NUM> would be pushed by the force of spring <NUM> axially along the damper housing <NUM> toward upper eyelet <NUM> and into the fluid chamber <NUM> reducing the exposed length <NUM> of spring retaining end <NUM>. This decrease in the exposed length <NUM> of spring retaining end <NUM> will translate to a decrease in the overall length of the spring preload piston assembly <NUM>.

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

In one embodiment, tube-in-shaft pump assembly <NUM> includes a pump tube <NUM> and a pumping action provided by the compression and rebound motion of damping piston <NUM> and shaft <NUM>. In one embodiment, pump tube <NUM> is used to pump fluid into fluid chamber <NUM> or draws fluid from the main chamber and/or out of fluid chamber <NUM>. In one embodiment, the fluid is pumped from the pump tube <NUM> into the fluid chamber <NUM> via the fluid paths controlled by check valve(s) <NUM> and/or tunable orifice(s) <NUM>.

In one embodiment, the pump tube <NUM> is located along the length of main chamber <NUM>. In one embodiment, damping piston <NUM> and shaft <NUM> will move along the length of pump tube <NUM> during rebound and compression strokes. In one embodiment, pump tube <NUM> includes at least one intake/exhaust port(s) <NUM>. In one embodiment, the intake/exhaust port(s) <NUM> is an opening in the pump tube <NUM> that is uncovered when the damping piston <NUM> and shaft <NUM> are below the opening (e.g., closer to lower eyelet <NUM> as shown in <FIG>), and is closed when damping piston <NUM> and shaft <NUM> are covering thereover (e.g., as shown in <FIG>).

In one embodiment, the location of the intake/exhaust port(s) <NUM> on the pump tube <NUM> is set such that when the vehicle is static at the established SAG, the damping piston <NUM> will be approximately located thereover.

In one embodiment, based on the SAG defined location of the intake/exhaust port(s) <NUM> in the pump tube <NUM> with respect to the damping piston <NUM>, when the vehicle is in operation, the intake/exhaust port(s) <NUM> is approximately half the time covered and half the time uncovered by the damping piston <NUM> at SAG ride height. In other words, intake/exhaust port(s) <NUM> is covered as the damping piston <NUM> and shaft <NUM> move toward the upper eyelet <NUM> in the compression stroke. In contrast, at some point in the rebound stroke when the damping piston <NUM> and shaft <NUM> move away from the upper eyelet <NUM> the intake/exhaust port(s) <NUM> would be uncovered.

In one embodiment, the pump tube <NUM> is filled with fluid and will pump the fluid into the fluid chamber <NUM> when the intake/exhaust port(s) <NUM> is covered during a compression stroke. In contrast, when the intake/exhaust port(s) <NUM> is uncovered, such as during a rebound stroke, the fluid will be drawn from the fluid chamber <NUM> and back into pump tube <NUM> (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) <NUM> tunes the ride height. If the damping piston <NUM> and shaft <NUM> are not covering the intake/exhaust port(s) <NUM>, fluid is released through the intake/exhaust port(s) <NUM> and into the main chamber, if the damping piston <NUM> and shaft <NUM> are covering the intake/exhaust port(s) <NUM>, the fluid is pumped up the pump tube <NUM> and into the fluid chamber <NUM>. Thus, at SAG, the fluid would be pumped into fluid chamber <NUM> during a compression stroke once the damping piston <NUM> and shaft <NUM> cover the intake/exhaust port(s) <NUM>, and would be released from the fluid chamber <NUM> during the rebound stroke after the damping piston <NUM> and shaft <NUM> uncover the intake/exhaust port(s) <NUM>.

In one embodiment, when weight is added to the vehicle, the overall shock assembly <NUM> length is shortened at least at the location where the weight is added. This reduction in shock assembly <NUM> length 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 assembly <NUM> length, causes the damping piston <NUM> and shaft <NUM> to move up the pump tube <NUM> closer to the upper eyelet <NUM>. As such, in a static situation, the intake/exhaust port(s) <NUM> will be covered by the damping piston <NUM> and shaft <NUM>.

Referring now to <FIG> a schematic diagram of the shock assembly riding low in a compression stroke is shown in accordance with an embodiment. In <FIG>, the fluid volumes are shown for the tube-in-shaft pump assembly <NUM> (e.g., P1), the main chamber <NUM> compression side (e.g., P2), and the spring preload piston assembly <NUM> (e.g., P3).

In one embodiment of the low riding compression stroke (having either high or low shaft speed), the main chamber <NUM> compression portion <NUM> P2 can be low or high. The tube-in-shaft pump assembly <NUM> P1 will be less than the main chamber <NUM> compression portion <NUM> P2. The tube-in-shaft pump assembly <NUM> P1 will be less than or equal to the spring preload piston assembly <NUM> P3. In one embodiment, the Vshaft can also be low or high.

<FIG> is a section view of shock assembly <NUM> illustrating the operation of <FIG> during a compression stroke, in accordance with an embodiment. In one embodiment, the components of <FIG> are similar to those of <FIG>. 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 of <FIG> is incorporated by reference in their entirety.

Referring now to <FIG> a schematic diagram of the shock assembly riding low in a rebound stroke is shown in accordance with an embodiment. In <FIG>, the fluid volumes are shown for the tube-in-shaft pump assembly <NUM> (e.g., P1), the main chamber <NUM> compression side (e.g., P2), and the spring preload piston assembly <NUM> (e.g., P3).

In one embodiment of the low riding rebound stroke (having either high or low shaft speed), the main chamber <NUM> compression portion <NUM> P2 is low. The tube-in-shaft pump assembly <NUM> P1 will be less than or equal to the main chamber <NUM> compression portion <NUM> P2. The tube-in-shaft pump assembly <NUM> P1 will be less than or equal to the spring preload piston assembly <NUM> P3. In one embodiment, the Vshaft can also be low or high.

In one embodiment, of an example of a low riding scenario, the damping piston <NUM> and shaft <NUM> are covering the intake/exhaust port(s) <NUM>. Therefore, during a compression stroke as shown in <FIG>, when the damping piston <NUM> and shaft <NUM> are covering the intake/exhaust port(s) <NUM> the fluid is pumped up the pump tube <NUM> and into the fluid chamber <NUM>. This addition of fluid will cause the fluid chamber <NUM> to expand which will cause spring retaining end <NUM> to move axially along the damping chamber increasing the exposed length <NUM> of spring retaining end <NUM>, and therefore, the overall length of spring preload piston assembly <NUM>. This increase in the overall length of spring preload piston assembly <NUM> would increase the overall length of shock assembly <NUM>. In other words, it would basically cause a virtual increase in the length of damper housing <NUM>.

With reference now to <FIG>, since the shock is riding low, during some or all of the rebound stroke, the damping piston <NUM> and shaft <NUM> would continue to cover the intake/exhaust port(s) <NUM> for a majority of even all of the rebound stroke. In the case where the intake/exhaust port(s) <NUM> remains covered, in one embodiment, some amount of fluid would be drawn from the fluid chamber <NUM> to fill the pump tube <NUM> and an additional amount of fluid would be drawn from the main chamber <NUM> into the shaft pump tube <NUM> as shown by arrow <NUM>.

At the next compression (again shown in <FIG>), the additional fluid that was added to the pump tube <NUM> from the main chamber <NUM>, in addition to the amount of fluid withdrawn from the fluid chamber <NUM>, would be pumped into fluid chamber <NUM>, which would further expand the size of fluid chamber <NUM> and again cause the spring retaining end <NUM> to be hydraulically pushed axial outward once again increasing the overall length of shock assembly <NUM>. By lengthening the shock assembly <NUM>, 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 in <FIG>) would begin to spend more time uncovering the intake/exhaust port(s) <NUM>. When the intake/exhaust port(s) <NUM> were uncovered by damping piston <NUM> and shaft <NUM>, an amount of fluid would be released from the pump tube <NUM> and therefore from the fluid chamber <NUM>.

In one embodiment, the pumping of more fluid into fluid chamber <NUM> than the drawing of fluid out of fluid chamber <NUM> would continue at an incrementally slower pace until the shock assembly <NUM> returned to SAG, at which point the pumping and releasing of fluid from fluid chamber <NUM> would 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 valve <NUM> may be closed such that the fluid will not leak out of fluid chamber <NUM>, 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 chamber <NUM> could be reached without the shock assembly <NUM> reaching SAG height. This could be due to the load causing a significant compression to spring <NUM> and thus the shortening of the axial length <NUM>. In this example, once the maximum size (or capacity) of fluid chamber <NUM> was reached, more fluid would still be being pumped toward fluid chamber <NUM> through pump tube <NUM> than was being released by fluid chamber <NUM>. However, since the size of fluid chamber <NUM> is maximized, in one embodiment, any additional fluid that is pumped toward the fluid chamber <NUM> would be released through the fluid relief valve <NUM>.

In one embodiment, if the shock assembly <NUM> were to encounter a significant event causing a large compression, some amount of the fluid pumped through pump tube <NUM> would also be dumped through the fluid relief valve <NUM>.

In one embodiment, when weight is removed from the vehicle, the overall shock assembly <NUM> length is increased at least at the location where the weight was removed. This increase in shock assembly <NUM> length 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 assembly <NUM> length, causes the damping piston <NUM> and shaft <NUM> to move down the pump tube <NUM> away from the upper eyelet <NUM>. As such, in a static situation, the intake/exhaust port(s) <NUM> will be uncovered by the damping piston <NUM> and shaft <NUM>.

Referring now to <FIG> a 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. In <FIG>, the fluid volumes are shown for the tube-in-shaft pump assembly <NUM> (e.g., P1), the main chamber <NUM> compression portion (e.g., P2), and the spring preload piston assembly <NUM> (e.g., P3).

In one embodiment of the riding high compression stroke having a low shaft speed, the main chamber <NUM> compression portion P2 is low. The tube-in-shaft pump assembly <NUM> P1 will be equal to the main chamber <NUM> compression portion P2. The tube-in-shaft pump assembly <NUM> P1 will be less than or equal to the spring preload piston assembly <NUM> P3. In one embodiment, the Vshaft will also be low.

<FIG> is 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. In <FIG>, the fluid volumes are shown for the tube-in-shaft pump assembly <NUM> (e.g., P1), the main chamber <NUM> compression portion (e.g., P2), and the spring preload piston assembly <NUM> (e.g., P3).

In one embodiment of the riding high compression stroke having a high shaft speed, the main chamber <NUM> compression portion P2 is high. The tube-in-shaft pump assembly <NUM> P1 will be equal to the main chamber <NUM> compression portion P2. The tube-in-shaft pump assembly <NUM> P1 will be less than or equal to the spring preload piston assembly <NUM> P3. In one embodiment, the Vshaft will also be high.

In one embodiment, if P2 is greater than P3, then P2 flows to P3 across O1, C1, and C2, <NUM>.

In one embodiment, if P3 is greater than P2, then P3 flows to P2 across C3, <NUM>, and O1.

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

<FIG> is a section view of shock assembly <NUM> illustrating the operation of <FIG> and <FIG> during a riding high compression stroke, in accordance with an embodiment. In one embodiment, the components of <FIG> are similar to those of <FIG>. 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 of <FIG> is incorporated by reference in their entirety.

Referring now to <FIG> a 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. In <FIG>, the fluid volumes are shown for the tube-in-shaft pump assembly <NUM> (e.g., P1), the main chamber <NUM> compression portion (e.g., P2), and the spring preload piston assembly <NUM> (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 chamber <NUM> compression portion P2 is low. The tube-in-shaft pump assembly <NUM> P1 will be less than or equal to the main chamber <NUM> compression portion P2. The tube-in-shaft pump assembly <NUM> P1 will be less than the spring preload piston assembly <NUM> P3. In one embodiment, the Vshaft can also be low or high.

<FIG> is a section view of shock assembly <NUM> illustrating the operation of <FIG>, e.g., shock assembly <NUM> riding high in a rebound stroke (having either high or low shaft speed) shown in accordance with an embodiment. In one embodiment, the components of <FIG> are similar to those of <FIG>. 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 of <FIG> is incorporated by reference in their entirety.

In one embodiment, in an example of a riding high scenario, the intake/exhaust port(s) <NUM> are not covered by the damping piston <NUM> and shaft <NUM>. Therefore, during a compression stroke as shown in <FIG>, as long as the intake/exhaust port(s) <NUM> remained uncovered, the fluid being pumped through pump tube <NUM> would flow out of the intake/exhaust port(s) <NUM> and into the main chamber. Similarly, the fluid in fluid chamber <NUM> would be subjected to the pressure applied by the movement of spring retaining end <NUM> moving axially along the damping chamber into the fluid chamber as it is being driven by the spring pressure of spring <NUM>. This pressure would cause fluid to drain from fluid chamber <NUM> into pump tube <NUM> and out of the intake/exhaust port(s) <NUM>.

In one embodiment, the movement of spring retaining end <NUM> into fluid chamber <NUM> will decrease the exposed length <NUM> of spring retaining end <NUM>, and therefore, the overall length of spring preload piston assembly <NUM>. This reduction in the overall length of spring preload piston assembly <NUM> would reduce the overall length of shock assembly <NUM>.

With reference now to <FIG>, since the shock is riding high, during the rebound stroke, the intake/exhaust port(s) <NUM> would remain uncovered and the pump tube <NUM> would continue to draw fluid from fluid chamber <NUM> as well as from main chamber <NUM>. As such, the fluid chamber <NUM> would continue to contract in size as the fluid drained and the spring retaining end <NUM> would continue to be pushed into the fluid chamber <NUM> by the spring force of spring <NUM> reducing the length of spring preload piston assembly <NUM> as well as the length of shock assembly <NUM>.

At the next compression (again shown in <FIG>), as long as the intake/exhaust port(s) <NUM> remain uncovered, fluid will continue to drain from the fluid chamber <NUM>, which would further reduce the size of fluid chamber <NUM> and again cause the exposed length <NUM> of spring retaining end <NUM> to be reduced, thereby continuing to reduce the overall length of shock assembly <NUM>. By reducing the length of shock assembly <NUM>, the ride height would continue to be reduced.

In one embodiment, process of draining fluid from fluid chamber <NUM> would 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 piston <NUM> and shaft <NUM> to begin to cover the intake/exhaust port(s) <NUM>. Once the compression stroke began to cover the intake/exhaust port(s) <NUM>, the draining of the fluid from fluid chamber <NUM> would continue at an incrementally slower pace until the shock assembly <NUM> returned to SAG, at which point the pumping and releasing of fluid into and out of fluid chamber <NUM> would again be back to an approximate equilibrium.

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

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

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

In one embodiment, relief valve <NUM> is configured to provide a fluid dump or rapid release of fluid from fluid chamber <NUM>. In one embodiment, the fluid relief valve <NUM> provides the fluid to the fluid reservoir when blow-off occurs.

Referring now to <FIG>, an alternate section view of the shock assembly <NUM> with shaft flow to base valve/reservoir is shown in accordance with an embodiment. In one embodiment, the shock assembly <NUM> of <FIG> shows the flow from the main chamber <NUM> through the base valve <NUM> and shows that the operation of the base valve <NUM> is not affected by the automatic ride height adjuster.

With reference now to <FIG>, embodiments of a shock assembly with an automatic ride height adjustment are described. In <FIG>, a number of the components and operation of the shock assembly were previously disclosed, or similar to those components previously disclosed, in the discussion of <FIG> which are incorporated by reference. However, in <FIG>, a tube-in-shaft pump assembly <NUM> with a spring and valve configuration is used in place of the tube-in-shaft pump assembly <NUM> with at least one intake/exhaust port <NUM> opening in pump tube <NUM>. In one embodiment, pump tube <NUM> is located the length of main chamber <NUM>.

Thus, the following discussion of <FIG>, will focus on the operational differences when the shock assembly <NUM> uses the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM>. For purposes of clarity, unless otherwise discussed, the remainder of the operation of the shock assembly <NUM> and will be similar to that already described in <FIG>.

In other words, the modification of <FIG> is directly related to the change from an intake/exhaust port(s) <NUM> in pump tube <NUM> to a spring and valve configuration <NUM>. Thus, the operation of spring preload piston assembly <NUM> remains the same.

With reference now to <FIG>, a schematic diagram <NUM> of a shock assembly with automatically adjustable ride height using a tube-in-shaft pump assembly <NUM> with the spring and valve configuration <NUM> to automatically adjustable ride height assembly in accordance with an embodiment. Schematic diagram <NUM> includes a spring preload piston assembly <NUM>, pump tube <NUM>, preload spring spacer <NUM>, preload spring <NUM>, valve <NUM>, bleed orifice <NUM>, low-pressure inlet check valve <NUM>, and fluid relief valve <NUM> (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, valve <NUM> is a poppet, a spool, or the like.

Referring now to <FIG>, a section view of a portion of a shock assembly with an automatically adjustable ride height assembly using a tube-in-shaft pump assembly <NUM> with the spring and valve configuration <NUM> is shown in accordance with an embodiment. In one embodiment, tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> includes a number of the components described in <FIG>.

In one embodiment, the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> includes components such as spring preload piston assembly <NUM>, pump tube <NUM>, a preload spring spacer <NUM>, a preload spring <NUM>, a valve <NUM>, a bleed orifice <NUM>, filter <NUM>, low-pressure inlet check valve <NUM>, high-pressure return path <NUM>. In one embodiment, the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> is used to fill and/or empty the fluid chamber <NUM> of spring preload piston assembly <NUM>.

In one embodiment, spring preload piston assembly <NUM> extends or contracts spring retaining end <NUM> to adjust the length of the spring preload piston assembly <NUM> thereby increasing or decreasing the length of shock assembly <NUM> to automatically adjust/return the ride height to SAG. In one embodiment, pump tube <NUM> forces fluid into the fluid chamber <NUM> when the shock is compressed and guides the preload spring <NUM> and preload spring spacer <NUM>.

In one embodiment, preload spring spacer <NUM> is used to tune or adjust the point in the damping piston <NUM> stroke when the preload spring <NUM> engages the valve <NUM>. In general, the preload spring <NUM> engages valve <NUM> when it provides enough force to close valve <NUM>. Otherwise, if the preload spring <NUM> does not provide enough force to close valve <NUM>, valve <NUM> will be disengaged.

In one embodiment, valve <NUM> controls the flow of fluid from the high-pressure return path <NUM>. When engaged by the preload spring <NUM>, fluid is pumped through the high-pressure checked supply path <NUM> into the fluid chamber <NUM>. However, when engaged, valve <NUM> will not allow fluid to leave the fluid chamber <NUM> via the high-pressure return path <NUM>.

When valve <NUM> is disengaged, fluid can still be pumped through the high-pressure checked supply path <NUM> into the fluid chamber <NUM>. However, and in contrast to the engaged popped, when valve <NUM> is disengaged, the fluid in fluid chamber <NUM> is also allowed leave via the high-pressure return path <NUM>.

In one embodiment, the bleed orifice <NUM> includes filter <NUM> and is used to control the rate at which the fluid bleeds out of the fluid chamber <NUM>, reducing preload, and lowering the vehicle. In one embodiment, the fluid of fluid chamber <NUM> can bleed through the bleed orifice <NUM> regardless of the position of valve <NUM> (e.g., engaged or disengaged).

In one embodiment, low-pressure inlet check valve <NUM> allows fluid to flow into the pump tube <NUM>. In one embodiment, the fluid flow from low-pressure inlet check valve <NUM> goes to the main shock body. In one embodiment, low-pressure inlet check valve <NUM> is provided after a base valve so the supply will always be low-pressure.

In one embodiment, fluid flow is shown between pump tube <NUM> and fluid chamber <NUM> of spring preload piston assembly <NUM>. In one embodiment, low-pressure inlet check valve <NUM> is a ball spring check valve. However, it should be appreciated that low-pressure inlet check valve <NUM> could 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 inlet <NUM> either 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 valve <NUM> is closed, when the shock assembly <NUM> is under significant load changes, the fluid flow is only closed in the direction of stopping fluid flow out of fluid chamber <NUM> of spring preload piston assembly <NUM>. Thus, in one embodiment, even when the check valve <NUM> is closed, the fluid can be pumped into fluid chamber <NUM> of spring preload piston assembly <NUM>.

In one embodiment, fluid relief valve <NUM> is a high-pressure blow-off. In one embodiment, as described herein, when the coil spring <NUM> is 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 valve <NUM> is configured to provide a fluid dump or rapid release of fluid from fluid chamber <NUM>, such as, for example, to prevent extreme pressures in system. In one embodiment, the fluid relief valve <NUM> provides the fluid released from fluid chamber <NUM> to the external fluid reservoir <NUM> when blow-off occurs.

In one embodiment, filter <NUM> is shown upstream of the bleed orifice <NUM> to filter large debris such as burrs from machining, poorly cleaned parts, assembly debris, etc. In one embodiment, the filter <NUM> is large enough to filter particles without restricting fluid flow.

For example, in a bleed orifice <NUM> with an inner diameter of <NUM> (. <NUM> of an inch), in one embodiment, the filter <NUM> would be less than <NUM> (. <NUM> inch).

As such, the filter <NUM> will stop larger particles that would plug the bleed orifice <NUM>, but it will allow smaller contaminants to pass through. In so doing, the filter <NUM> will not become clogged with smaller particles. Referring now to <FIG>, are section views of the shock assembly <NUM> riding in different configurations during compression and rebound are shown in accordance with an embodiment. In one embodiment, shock assembly <NUM> of <FIG> include the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM>, the spring preload piston assembly <NUM>, main chamber <NUM> within damper housing <NUM>, damping piston <NUM> fixed to shaft <NUM>, coil spring <NUM>, and upper eyelet <NUM>.

In one embodiment, the damping piston <NUM> and shaft <NUM> are axially movable toward or away from upper eyelet <NUM> within main chamber <NUM> axially along pump tube <NUM>. In one embodiment, the movement of damping piston <NUM> and shaft <NUM> will also include the movement of preload spring spacer <NUM>. For example, during compression, damping piston <NUM>, shaft <NUM>, and preload spring spacer <NUM> move axially through main chamber <NUM> toward upper eyelet <NUM>. In contrast, during rebound, damping piston <NUM>, shaft <NUM>, and preload spring spacer <NUM> move axially through main chamber <NUM> away from upper eyelet <NUM>. In one embodiment there is an external fluid reservoir <NUM>.

In one embodiment, tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> uses the compression and rebound motion of damping piston <NUM>, shaft <NUM>, and preload spring spacer <NUM> to pump fluid from the main chamber <NUM> (or another fluid chamber such as a low-pressure reservoir fluid chamber) into fluid chamber <NUM> and/or bleed (or withdraw) fluid from fluid chamber <NUM> and back to the main chamber <NUM> (or another fluid chamber such as a low-pressure reservoir fluid chamber). In one embodiment, the fluid is pumped from the pump tube <NUM> into the fluid chamber <NUM> via the fluid flow path(s) <NUM> (such as high-pressure return path <NUM>) controlled by check valve(s) <NUM> (such as the check valve on low-pressure inlet check valve <NUM>), tunable orifice(s) <NUM>, and the like.

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

In one embodiment, the SAG for shock assembly <NUM> is set by adjusting the location of the preload spring spacer <NUM> to tune the point in the damping piston <NUM> stroke when the preload spring <NUM> engages the valve <NUM>. Thus, adjusting the preload spring spacer <NUM> will establish the SAG, in the same way that adjusting the location of intake/exhaust port(s) <NUM> opening set the SAG.

In one embodiment, the location of the preload spring spacer <NUM> along the pump tube <NUM> and in relation to the preload spring <NUM> and the spring force it exerts on valve <NUM> are preset at the factory. In one embodiment, the location of preload spring spacer <NUM> is adjustable along the length of the pump tube <NUM> within shaft <NUM> to 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 spacer <NUM> with regard to the preload spring <NUM> and the spring force it exerts on valve <NUM> is changed by replacing the existing preload spring spacer <NUM> with another preload spring spacer <NUM> of a different length, thereby establishing a new SAG.

In one embodiment, the location of preload spring spacer <NUM> is user adjustable along the length of the shaft <NUM> to adjust the SAG. For example, the rotation of pump tube <NUM> (and/or shaft <NUM>, or another control surface) will adjust the location of preload spring spacer <NUM> within pump tube <NUM> which will modify the relationship with the preload spring <NUM> and the spring force it exerts on valve <NUM>.

In one embodiment, once the desired SAG ride height is established. The preload spring spacer <NUM> will be located such that when in SAG, the preload spring <NUM> will exert an amount of spring force on valve <NUM> that will not be engaged. However, as the damping piston <NUM> and shaft <NUM> move 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 spacer <NUM> will push against the preload spring <NUM> such that the additional amount of spring force applied to valve <NUM> will engage valve <NUM>. When valve <NUM> is engaged, fluid will be added to fluid chamber <NUM>.

In contrast, while the vehicle is in SAG ride height, on a rebound stroke the preload spring spacer <NUM> will release an amount of pressure applied to the preload spring <NUM> such that the reduced amount of spring force from preload spring <NUM> will disengage valve <NUM>. When valve <NUM> is disengaged, fluid will be bled from fluid chamber <NUM>.

Thus, when the vehicle is in SAG ride height, the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> will maintain the SAG ride height by pumping fluid into and releasing fluid from fluid chamber <NUM>.

In one embodiment, if a change in the SAG ride height was desired, the location of preload spring spacer <NUM> would be adjusted (e.g., user adjusted, manually adjusted, automatically adjusted, or the like), which would change the SAG ride height location of damping piston <NUM> within main chamber <NUM> and similarly adjust the force applied to preload spring <NUM> and thus, the spring force it exerts on valve <NUM>. In so doing, an adjustment in the preload spring spacer <NUM> would result in a different ride height SAG setting.

In one embodiment, preload spring <NUM> could be replaced with a preload spring <NUM> having a different length to modify the desired SAG ride height. In one embodiment, preload spring <NUM> could be replaced with a preload spring <NUM> having a different spring constant to modify the desired SAG ride height. In one embodiment, preload spring <NUM> could be replaced with a preload spring <NUM> having 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 spacer <NUM>, the length of preload spring spacer <NUM>, the length of preload spring <NUM>, and/or the spring constant of preload spring <NUM> could be adjusted to change the SAG ride height.

In one embodiment, the pump tube <NUM> of the tube-in-shaft pump assembly <NUM> may include an interior tube that utilizes the spring and valve configuration <NUM>, and an exterior tube (e.g., a larger pump tube surrounding a smaller pump tube) that has the intake/exhaust port(s) <NUM> opening such that the tube-in-shaft pump assembly <NUM> would 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 assembly <NUM> were 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 assembly <NUM> for a normal vehicle (e.g., a side-by-side, motorcycle, pick-up truck, etc.), the amount of fluid that could be pushed into fluid chamber <NUM> would be large enough that the operation of both of the disclosed tube-in-shaft pump assembly <NUM> configurations would provide a more efficient capability to maintain the SAG ride height as the vehicle is loaded and/or unloaded.

As stated herein, <FIG> is a section view of the shock assembly <NUM> having the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> riding low in a compression stroke in accordance with an embodiment. In contrast, <FIG> is a section view of the shock assembly <NUM> having the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> riding 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 assembly <NUM> length is shortened at least at the location where the weight is added. This reduction in shock assembly <NUM> length 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 in <FIG> and <FIG>. In one embodiment, the shortening of the shock assembly <NUM> length, causes damping piston <NUM>, shaft <NUM>, and preload spring spacer <NUM> to move up the pump tube <NUM> closer to the upper eyelet <NUM>. As such, in a static situation, the valve <NUM> will be engaged by preload spring <NUM>.

In one embodiment, during a compression stroke as shown in <FIG>, when the valve <NUM> is engaged the fluid is pumped up the pump tube <NUM> and into the fluid chamber <NUM> via the high-pressure checked supply path <NUM>. In other words, pump tube <NUM> can pump fluid through the high-pressure checked supply path <NUM> even when preload spring <NUM> is engaging valve <NUM>. In one embodiment, a majority of the fluid flows through the flow paths indicated by the light flow arrows of <FIG>. In one embodiment, a small amount of pump flow is lost across the open bleed orifice <NUM> as shown by the dotted arrow. However, as long as valve <NUM> is engaged, high-pressure return path <NUM> will be closed and fluid will not be able to leave fluid chamber <NUM> via the closed high-pressure return path <NUM>.

In one embodiment, the additional fluid pumped into fluid chamber <NUM> will cause fluid chamber <NUM> to expand causing spring retaining end <NUM> to move axially along the damping chamber increasing the exposed length <NUM> of spring retaining end <NUM>. This will increase the overall length of spring preload piston assembly <NUM> which will increase the overall length of shock assembly <NUM> and cause the ride height to begin to rise.

With reference now to <FIG>, since the shock is riding low, during some or all of the rebound stroke, the valve <NUM> will remain engaged for a majority of even all of the rebound stroke. In one embodiment, while the valve <NUM> is engaged, high-pressure return path <NUM> will be closed and fluid will not be able to leave fluid chamber <NUM> via the closed high-pressure return path <NUM>. In one embodiment, the fluid that refills the pump tube will flow through the low-pressure inlet check valve <NUM> (as shown by the light arrow).

At the next compression (again shown in <FIG>), the fluid that was added to the pump tube <NUM> during rebound would be pumped into fluid chamber <NUM> via the high-pressure checked supply path <NUM>, which would again expand the size of fluid chamber <NUM> and again cause the spring retaining end <NUM> to be hydraulically pushed axial outward increasing the overall length of shock assembly <NUM> and the ride height.

In one embodiment, the fluid chamber <NUM> filling 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 in <FIG>) causes the preload spring <NUM> pressure on valve <NUM> to drop below the pressure on valve <NUM> from the fluid in high-pressure return path <NUM>. When that transition does occur, valve <NUM> will disengage. When valve <NUM> is disengaged, an amount of fluid would be released from fluid chamber <NUM> through the high-pressure return path <NUM>. After that point, such as during the next compression stroke, the valve <NUM> would be engaged and then during part of the rebound stroke the valve <NUM> would be disengaged.

However, the valve <NUM> would likely spend a larger amount of time engaged than disengaged which would mean the pumping of more fluid into fluid chamber <NUM> than the removal of fluid from fluid chamber <NUM> would continue, although at a slower pace, until the shock assembly <NUM> returned to SAG, at which point the pumping and releasing of fluid from fluid chamber <NUM> would 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 spring <NUM> force on valve <NUM> would keep valve <NUM> engaged keeping the high-pressure return path <NUM> closed. 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 valve <NUM> (and or fluid relief valve <NUM>) can also be closed such that the fluid will not leak out of fluid chamber <NUM>, 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 chamber <NUM> could be reached without the shock assembly <NUM> reaching SAG height. This could be due to the load causing a significant compression to coil spring <NUM> and thus the shortening of the axial length <NUM>. In this example, once the maximum size (or capacity) of fluid chamber <NUM> was reached, more fluid would still be being pumped from pump tube <NUM> through the high-pressure checked supply path <NUM> toward fluid chamber <NUM>. However, since the size of fluid chamber <NUM> is maximized, in one embodiment, any additional fluid that is pumped from pump tube <NUM> through the high-pressure checked supply path <NUM> toward the fluid chamber <NUM> would be released through the fluid relief valve <NUM>.

In one embodiment, if the shock assembly <NUM> were to encounter a significant event causing a large compression, some amount of the fluid pumped from pump tube <NUM> through the high-pressure checked supply path <NUM> would also be dumped through the fluid relief valve <NUM>.

As stated herein, <FIG> is a section view of the shock assembly <NUM> having the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> riding high in a compression stroke in accordance with an embodiment. In contrast, <FIG> is a section view of the shock assembly <NUM> having the tube-in-shaft pump assembly <NUM> with a spring and valve configuration <NUM> riding high in a rebound stroke in accordance with an embodiment.

In one embodiment, when weight is removed from the vehicle, the shock assembly <NUM> length is increased at least at the location where the weight was removed. In one embodiment, the increase of the shock assembly <NUM> length, causes damping piston <NUM>, shaft <NUM>, and preload spring spacer <NUM> to move down the pump tube <NUM> away from the upper eyelet <NUM>. This increase in shock assembly <NUM> length 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 in <FIG> and <FIG>. In one embodiment of the riding high rebound stroke, the fluid volumes and pressures are similar to those described in <FIG>.

In one embodiment, in an example of a riding high scenario, the valve <NUM> is disengaged due to the lack of spring force on valve <NUM> from preload spring <NUM>. Since the valve <NUM> is disengaged, the fluid in fluid chamber <NUM> is able to flow out of the fluid chamber <NUM> through the open high-pressure return path <NUM>. This will allow the spring retaining end <NUM> to begin to retract into fluid chamber <NUM> which will decrease the exposed length <NUM> of spring retaining end <NUM>, and therefore reduce the overall length of spring preload piston assembly <NUM>. Reducing the overall length of spring preload piston assembly <NUM> will reduce the overall length of shock assembly <NUM> and cause the vehicle ride height to lower.

During a compression stroke as shown in <FIG>, the fluid being pumped through pump tube <NUM> would flow into the high-pressure checked supply path <NUM>. However, as long as valve <NUM> remains disengaged, the fluid in fluid chamber <NUM> will continue to flow out of fluid chamber <NUM> through the open high-pressure return path <NUM>. In one embodiment, some small amount of pump flow would also be lost across the open bleed orifice <NUM>.

In one embodiment, fluid will leave fluid chamber <NUM> as it will be subjected to the pressure applied by the movement of spring retaining end <NUM> moving axially along the damping chamber into the fluid chamber as it is being driven by the spring pressure of coil spring <NUM>. This pressure would cause fluid to drain from fluid chamber <NUM>.

In one embodiment, the movement of spring retaining end <NUM> into fluid chamber <NUM> will decrease the exposed length <NUM> of spring retaining end <NUM>, and therefore, reduce the overall length of spring preload piston assembly <NUM> and the overall length of shock assembly <NUM>.

With reference now to <FIG>, since the shock assembly <NUM> is riding high, during the rebound stroke, valve <NUM> would remain disengaged and the fluid that was pumped into high-pressure checked supply path <NUM> during the compression stroke will not be restricted by valve <NUM> and will return to refill the pump tube <NUM>. At the same time, fluid would continue to drain from fluid chamber <NUM> via high-pressure return path <NUM>. Therefore, in one embodiment, during rebound the fluid chamber <NUM> would continue to contract in size as the fluid drained from fluid chamber <NUM> and the spring retaining end <NUM> would continue to be pushed into the fluid chamber <NUM> by the spring force of coil spring <NUM> reducing the length of spring preload piston assembly <NUM> as well as the length of shock assembly <NUM>.

At the next compression (again shown in <FIG>), as long as valve <NUM> remains disengaged, fluid will continue to be pumped into high-pressure checked supply path <NUM> and drain from the fluid chamber <NUM> via high-pressure return path <NUM>. At the next rebound, the fluid in high-pressure checked supply path <NUM> would return to refill the pump tube <NUM>, and additional fluid would continue to leave fluid chamber <NUM> via high-pressure return path <NUM> which would further reduce the size of fluid chamber <NUM> and again cause the exposed length <NUM> of spring retaining end <NUM> to be reduced, thereby continuing to reduce the ride height.

In one embodiment, the draining of fluid from fluid chamber <NUM> would 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 spacer <NUM> to begin to engage valve <NUM>. Once the compression stroke began to engage valve <NUM>, the draining of the fluid from fluid chamber <NUM> via high-pressure return path <NUM> would stop when the valve <NUM> was engaged, but begin again when valve <NUM> was disengaged (such as during a portion of the rebound stroke). As such, the reduction of fluid from fluid chamber <NUM> would continue at an incrementally slower pace until the shock assembly <NUM> returned to SAG, at which point the pumping and releasing of fluid into and out of fluid chamber <NUM> would again be back to an approximate equilibrium.

In one embodiment, fluid relief valve <NUM> is configured to provide a fluid dump or rapid release of fluid from fluid chamber <NUM>. In one embodiment, the fluid relief valve <NUM> provides the fluid to the fluid reservoir when blow-off occurs.

With reference now to <FIG>, a graph of spring force versus travel <NUM> for 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 travel <NUM> shows 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 travel <NUM>, the spring preload system can add an additional 2224N (500lb) of force per shock for added payload. In one embodiment, as shown in the graph of spring force versus travel <NUM> the automatic ride height adjustment system has <NUM>" of preload capability, and vehicle uses a <NUM>. 8N/mm (<NUM> lb/in) spring.

<FIG> is a graph of spring/valve opening forces <NUM> for 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 forces <NUM> is an example showing the forces required to close the valve tuned for an engagement shock stroke of <NUM>" as indicated by the vertical engaged line at the <NUM>" mark on the graph of spring/valve opening forces <NUM>. 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.

Mark <NUM> indicates when the preload spring <NUM> would begin to be engaged. At about <NUM> (<NUM> inches) of shock stroke, if there is no spring preload on the system, it will start to pump-up the spring preload piston assembly <NUM>. In contrast, if there is full-preload on the system, it will attempt to start pumping up the spring preload piston assembly <NUM> at about <NUM> (<NUM> 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 valve <NUM>, intake/exhaust port(s) <NUM>, valve <NUM>, 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 valve <NUM>, intake/exhaust port(s) <NUM>, valve <NUM>, and the like) are automatically adjustable such as via the use of an active valve <NUM>.

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 valve <NUM> open or closing, moving the location of the intake/exhaust port(s) <NUM>, the fluid chamber <NUM> including a check valve <NUM>, the blow-off setting of relief valve <NUM>, the size of tunable orifice <NUM> is 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 chamber <NUM> could be automatically reduced using check valve <NUM> and/or relief valve <NUM>.

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 tube <NUM> provides a fluid flow path between a rebound portion of the damper and fluid chamber <NUM>. In one embodiment, the pump tube <NUM> is located within shaft <NUM>, that is, it is internal to the shaft <NUM>. In another embodiment, pump tube <NUM> is partially (or completely) external of the shaft <NUM>.

In one embodiment, valve <NUM> is a check valve. However, it should be appreciated that valve <NUM> could 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 spacer <NUM> in the pump tube <NUM> is located with respect to the preload spring <NUM> such that the pressure on preload spring <NUM> will keep valve <NUM> closed 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., <NUM> (140lbs.

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 (<NUM> (200lbs. )) and the suspension ride height (e.g., the established SAG for the vehicle) is lowered due to the compression of shock assembly <NUM>.

In one embodiment, by utilizing the automatic ride height adjustment assembly, the system would adjust the fluid volume in fluid chamber <NUM> as 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 chamber <NUM> (as described herein), thereby returning the ride height to the established SAG. This time, for example, the amount of fluid in fluid chamber <NUM> would be reduced so that the overall length of shock assembly <NUM> would 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 <NUM> reduction in height from the established SAG, during suspension operation as described above, the axial length of spring preload piston assembly <NUM> would 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 assembly <NUM>.

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 assembly <NUM> would 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 assembly <NUM>.

Therefore, if a vehicle is loaded with an additional <NUM> (500lbs. ) of cargo in the rear, the extra 2224N (<NUM>-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.

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 assembly <NUM> are active valves as described in further detail in <FIG>. In one embodiment, one or more of the valves within shock assembly <NUM> are non-active valves, e.g., a manual valve that may be adjustable but is not electronically adjustable.

Referring now to <FIG>, an enlarged view of an active valve <NUM> is 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".

Although <FIG> shows the active valve <NUM> in a closed position (e.g. during a rebound stroke of the damper), the following discussion also includes the opening of active valve <NUM>. Active valve <NUM> includes a valve body <NUM> housing a movable piston <NUM> which is sealed within the body. The piston <NUM> includes a sealed chamber <NUM> adjacent an annularly-shaped piston surface <NUM> at a first end thereof. The chamber <NUM> and annular piston surface <NUM> are in fluid communication with a port <NUM> accessed via opening <NUM>. Two additional fluid communication points are provided in the body including an inlet orifice <NUM> and an outlet orifice <NUM> for fluid passing through the active valve <NUM>.

Extending from a first end of the piston <NUM> is a shaft <NUM> having a cone-shaped nipple <NUM> (other shapes such as spherical or flat, with corresponding seats, will also work suitably well) disposed on an end thereof. The nipple <NUM> is telescopically mounted relative to, and movable on, the shaft <NUM> and is biased toward an extended position due to a spring <NUM> coaxially mounted on the shaft <NUM> between the nipple <NUM> and the piston <NUM>. Due to the spring biasing, the nipple <NUM> normally seats itself against a seat <NUM> formed in an interior of the valve body <NUM>.

As shown, the nipple <NUM> is seated against seat <NUM> due to the force of the spring <NUM> and absent an opposite force from fluid entering the active valve <NUM> along orifice <NUM>. As nipple <NUM> telescopes out, a gap <NUM> is formed between the end of the shaft <NUM> and an interior of nipple <NUM>. A vent <NUM> is provided to relieve any pressure formed in the gap. With a fluid path through the active valve <NUM> (from <NUM> to <NUM>) 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 arrow <NUM>.

In one embodiment, there is a manual pre-load adjustment on the spring <NUM> permitting a user to hand-load or un-load the spring using a threaded member <NUM> that transmits motion of the piston <NUM> towards and away from the conical member, thereby changing the compression on the spring <NUM>.

Also shown in <FIG> is a plurality of valve operating cylinders <NUM>, <NUM>, <NUM>. In one embodiment, the cylinders each include a predetermined volume of fluid <NUM> that is selectively movable in and out of each cylindrical body through the action of a separate corresponding piston <NUM> and rod <NUM> for each cylindrical body. A fluid path <NUM> runs between each cylinder and port <NUM> of the valve body where annular piston surface <NUM> is exposed to the fluid.

Because each cylinder has a specific volume of substantially incompressible fluid and because the volume of the sealed chamber <NUM> adjacent the annular piston surface <NUM> is 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 cylinders <NUM>-<NUM> can be operated in any fashion, in the embodiment shown each piston <NUM> and rod <NUM> is individually operated by a solenoid <NUM> and 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 solenoids <NUM> is 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 valve <NUM> is in the damping-open position, fluid flow through orifice <NUM> provides adequate force on the nipple <NUM> to urge it backwards, at least partially loading the spring <NUM> and creating a fluid flow path from the orifice <NUM> into and through orifice <NUM>.

The characteristics of the spring <NUM> are typically chosen to permit active valve <NUM> (e.g. nipple <NUM>) to open at a predetermined pressure, with a predetermined amount of control pressure applied to port <NUM>. For a given spring <NUM>, higher control pressure at port <NUM> will result in higher pressure required to open the active valve <NUM> and correspondingly higher damping resistance in orifice <NUM>. In one embodiment, the control pressure at port <NUM> is 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 nipple <NUM> is "topped out" against valve body <NUM>. In another embodiment however, when the valve piston <NUM> is abutted or "topped out" against valve body <NUM> the spring <NUM> and relative dimensions of the active valve <NUM> still allow for the nipple <NUM> to engage the valve seat <NUM> thereby 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 orifice <NUM> is determined by the pre-compression in the spring <NUM>. In such embodiment, additional fluid pressure may be added to the inlet through port <NUM> to increase the cracking pressure for flow along orifice <NUM> and 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 valve <NUM> can 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 valve <NUM> is 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 orifice <NUM> by causing nipple <NUM> to open, close, or partially close orifice <NUM>) 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 valve <NUM> (and corresponding change to the working size of the opening of orifice <NUM> by causing nipple <NUM> to open, close, or partially close orifice <NUM>) in response thereto. In another example, active valve <NUM> is 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 orifice <NUM> by causing nipple <NUM> to open, close, or partially close orifice <NUM>) in the event of, for example, an increased or decreased pressure reading. In one embodiment, active valve <NUM> is 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 orifice <NUM> by causing nipple <NUM> to open, close, or partially close orifice <NUM> chambers) in the event of a loss of control to help the operator of the vehicle to regain control.

For example, active valve <NUM>, when open, permits a first flow rate of the fluid through orifice <NUM>. In contrast, when active valve <NUM> is partially closed, a second flow rate of the fluid though orifice <NUM> occurs. The second flow rate is less than the first flow rate but greater than no flow rate. When active valve <NUM> is completely closed, the flow rate of the fluid though orifice <NUM> is statistically zero.

In one embodiment, instead of (or in addition to) restricting the flow through orifice <NUM>, active valve <NUM> can vary a flow rate through an inlet or outlet passage within the active valve <NUM>, itself. See, as an example, the electronic valve of <FIG> of U. Patent <NUM>,<NUM>,<NUM> as further example of different types of "electronic" or "active" valves). Thus, the active valve <NUM>, 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 orifice <NUM>.

Due to the active valve <NUM> arrangement, a relatively small solenoid (using relatively low amounts of power) can generate relatively large damping forces. Furthermore, due to incompressible fluid inside the shock assembly <NUM>, damping occurs as the distance between nipple <NUM> and orifice <NUM> is reduced. The result is a controllable damping rate. Certain active valve features are described and shown in <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>.

It should be appreciated that when the body <NUM> rotates in a reverse direction than that described above and herein, the nipple <NUM> moves away from orifice <NUM> providing at least a partially opened fluid path.

<FIG> is a schematic diagram showing a control arrangement <NUM> for a remotely-operated active valve <NUM>. As illustrated, a signal line <NUM> runs from a switch <NUM> to a solenoid <NUM>. Thereafter, the solenoid <NUM> converts electrical energy into mechanical movement and rotates body <NUM> within active valve <NUM>, In one embodiment, the rotation of body <NUM> causes 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 body <NUM> rotates, nipple <NUM> at an opposite end of the valve is advanced or withdrawn from an opening in orifice <NUM>. For example, the body <NUM> is rotationally engaged with the nipple <NUM>. A male hex member extends from an end of the body <NUM> into a female hex profile bore formed in the nipple <NUM>. Such engagement transmits rotation from the body <NUM> to the nipple <NUM> while allowing axial displacement of the nipple <NUM> relative to the body <NUM>. Therefore, while the body does not axially move upon rotation, the threaded nipple <NUM> interacts 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 nipple <NUM> towards or away from an orifice <NUM>, between a closed position, a partially open position, and a fully or completely open position.

Adjusting the opening of orifice <NUM> modifies the flowrate of the fluid through active valve <NUM> thereby varying the stiffness of a corresponding shock assembly <NUM>. While <FIG> is simplified and involves control of a single active valve <NUM>, 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 reservoir <NUM>, etc. In other words, anywhere there is a fluid flow path within a shock assembly <NUM>, 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 of <FIG>, the remotely-operable active valve <NUM> can 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> shows a schematic diagram of a control system <NUM> based upon any or all of vehicle speed, damper rod speed, and damper rod position. One embodiment of the arrangement of <FIG> is 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 system <NUM> adds damping (and control) in the event of rapid operation (e.g. high rod velocity) of the shock assembly <NUM> to 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 system <NUM> adds damping (e.g., adjusts the size of the opening of orifice <NUM> by causing nipple <NUM> to open, close, or partially close orifice <NUM>) 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 "gout.

<FIG> illustrates, for example, a control system <NUM> including three variables: wheel speed, corresponding to the speed of a vehicle component (measured by wheel speed transducer <NUM>), piston rod position (measured by piston rod position transducer <NUM>), and piston rod velocity (measured by piston rod velocity transducer <NUM>). Any or all of the variables shown may be considered by logic unit <NUM> in controlling the solenoids or other motive sources coupled to active valve <NUM> for changing the working size of the opening of orifice <NUM> by causing nipple <NUM> to open, close, or partially close orifice <NUM>. 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 <CIT>.

While transducers located at the suspension damper measure piston rod velocity (piston rod velocity transducer <NUM>), and piston rod position (piston rod position transducer <NUM>), a separate wheel speed transducer <NUM> for 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 <CIT>.

In one embodiment, as illustrated in <FIG>, the logic unit <NUM> with user-definable settings receives inputs from piston rod position transducer <NUM>, piston rod velocity transducer <NUM>, as well as wheel speed transducer <NUM>. Logic unit <NUM> is user-programmable and, depending on the needs of the operator, logic unit <NUM> records the variables and, then, if certain criteria are met, logic unit <NUM> sends its own signal to active valve <NUM> (e.g., the logic unit <NUM> is an activation signal provider) to cause active valve <NUM> to move into the desired state (e.g., adjust the flow rate by adjusting the distance between nipple <NUM> and orifice <NUM>). Thereafter, the condition, state or position of active valve <NUM> is relayed back to logic unit <NUM> via an active valve monitor or the like.

In one embodiment, logic unit <NUM> shown in <FIG> assumes a single active valve <NUM> corresponding to a single orifice <NUM> of a single shock assembly <NUM>, but logic unit <NUM> is 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 like <FIG>, or in another embodiment, into a shock assembly with more, fewer, or different components than those shown in <FIG>. 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.

Claim 1:
A shock assembly (<NUM>) comprising:
a main chamber (<NUM>) comprising a fluid therein;
a pump tube (<NUM>) within said main chamber, said pump tube having a fluid flow path internal thereto, said pump tube disposed axially along a center of said main chamber;
a damping piston (<NUM>) coupled to a shaft (<NUM>), said damping piston and a portion of said shaft disposed axially about said pump tube (<NUM>), said damping piston disposed in said main chamber to divide said main chamber into a compression side fluid chamber and a rebound side fluid chamber; and
an automatic ride height adjustment assembly comprising:
a tube-in-shaft pump assembly (<NUM>); and
a spring preload piston assembly (<NUM>);
wherein said tube-in-shaft pump assembly (<NUM>) comprises:
an intake/exhaust port (<NUM>) through a portion of said pump tube (<NUM>); and
a fluid (<NUM>, <NUM>) path from said pump tube to said spring preload piston assembly,
wherein an axial motion of said damping piston (<NUM>) and said shaft (<NUM>) along said pump tube (<NUM>) during a compression stroke pumps said fluid through said pump tube and into said spring preload piston assembly (<NUM>);
characterized in that a SAG ride height is established by an axial location of said intake/exhaust port (<NUM>) of said pump tube (<NUM>).