Patent Description:
Embodiments of the invention generally relate to methods and apparatus for use in vehicle suspension. In particular the present invention relates to a shock assembly, to a monotube shock assembly comprising the shock assembly, to a piggyback shock assembly comprising the shock assembly, and to a vehicle comprising the shock assembly, or the monotube shock assembly or the piggyback 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>-pound rider on a motorcycle may have a shock set to a softer setting to provide a comfortable ride. However, when a <NUM>-pound rider rides the same motorcycle with the same shock setting, the shock would likely have a much shorter length of available travel. Similarly, if the shock 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 to obtain performance characteristics similar to the lighter rider and vice-versa.

<CIT> discloses a damper including a piston rod, a damping piston, at least one cylinder containing a damping liquid, a fixed partition member for partitioning the interior of the damper into two liquid chambers, a pressure source, and a valve in communication with the pressure source which reacts as a function of the pressure. The valve can also be in communication with additional forces, such as mechanical spring forces, which can be adjustable. The valve can include a pressure intensifier. The valve generates fluid flow resistance during flow of liquid in a first direction through the partition member. The fluid flow resistance in the first direction varies according to the amount of force communicated to the valve by the pressure source and any additional forces. The partition member can include means for providing low resistance return flow of liquid in a second direction.

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

In an embodiment said shock assembly may be a monotube shock assembly. Said IFP pump assembly may be disposed in said compression side fluid chamber of said main chamber. In an embodiment said shock assembly may be a piggyback shock assembly. The piggyback shock assembly may comprise a remote reservoir. The IFP pump assembly may be disposed in said remote reservoir.

In an embodiment said pump may comprise a pump body. The pump may comprise a post fixedly coupled with and extended from said pump body toward said IFP. A distance from an end of said post to said IFP may establish a SAG ride height. The pump may comprise a pump chamber to receive said working fluid from said fluid reservoir. The pump chamber may be configured to pump said working fluid through said fluid pathway to said spring preload piston assembly when said post and said pump body are pressed into said pump chamber.

In an embodiment the post may be adjustably coupled with said pump body to adjustably change a length of the post that is extended from said pump body toward said IFP. A distance from an end of said post to said IFP may be adjusted by said change in said length of the post that is extended from said pump body to modify said SAG ride height.

In an embodiment a compression stroke of said damping piston may cause said IFP to contact said post and press said post and said pump body into said pump chamber.

In an embodiment, after said compression stroke, a rebound stroke of said damping piston may cause said IFP to move away from said post and allow said post and said pump body to withdraw from said pump chamber.

In an embodiment the shock assembly may further comprise a check tunable orifice. The fluid reservoir may provide said working fluid to said pump via said check tunable orifice.

In an embodiment the check tunable orifice may be adjustably configurable to limit a refill speed of said working fluid from said fluid reservoir to said pump.

In an embodiment said spring preload piston assembly may comprise a fluid chamber in fluid communication with a fluid pathway of said IFP pump assembly. The spring preload assembly may also comprise a spring retainer that extends from a portion of said fluid chamber. The spring retainer may be axially adjustable along said main chamber, such that a change in an amount of said working fluid in said fluid chamber automatically changes a length of the spring retainer that extends from said fluid chamber which changes a ride height of said shock assembly.

In an embodiment when said working fluid is added to said fluid chamber said fluid chamber may be configured to expand and push the spring retainer a further length out of said fluid chamber to cause an increase in said ride height of said shock assembly.

In an embodiment the shock assembly may further comprise a bleed control valve that may be configured to allow at least some of said working fluid to be released from said fluid chamber. When said at least some of said working fluid is released from said fluid chamber, said fluid chamber may be configured to contract and reduce the length of said spring retainer that extends out of said fluid chamber to cause a decrease in said ride height of said shock assembly.

In an embodiment said bleed control valve may be a passive valve.

In an embodiment said bleed control valve may be a semi-active valve.

In an embodiment the shock assembly may further comprise a fluid relief valve which may be configured to provide a rapid fluid dump when an amount of fluid greater than an available volume of said fluid chamber is pumped from said IFP pump assembly to said fluid chamber, and when a compression event causes said working fluid in said fluid chamber to surpass a pre-established blow-off value.

According to another aspect of the present invention there is provide a monotube shock assembly comprising a shock assembly as set out above.

According to another aspect of the present invention there is provide a piggyback shock assembly comprising a shock assembly as set out above.

According to another aspect of the present invention there is provided a vehicle comprising a shock assembly, a monotube shock assembly or a piggyback shock assembly as set out above.

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, working fluid of "fluid" refers to a non-compressible fluid that is used in one or more aspects of the shock assembly. Examples of a non-compressible fluid include liquids such as oils, water, and the like. Compressible fluid refers to a fluid that is used in one or more aspects of the internal floating piston (IFP) assembly. Examples of compressible fluid includes gases such as nitrogen, carbon dioxide, air, and the like. 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> 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>-inch ride height (a middle of the performance envelope) based on a rider with a weight of <NUM> lbs. This would mean that unencumbered, the motorcycle would have a seat height that was higher than <NUM> inches of ride height (such as for example, a seat height of <NUM> inches). However, when a <NUM> lb. rider sits on the motorcycle, the suspension would compress and the motorcycle would be at the SAG ride height of <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> inches. In contrast, if the user wanted a higher ride height, they could increase the SAG to <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> lbs. , when the rider sat on the motorcycle, the ride height would be lower than the <NUM> inches. As such, the rider would adjust one or more of the suspension components to return the motorcycle to the <NUM>-inch SAG.

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

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

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

For example, if a vehicle is loaded with an additional <NUM> lbs. of cargo in the rear, the extra <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 in 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 general, in a shock assembly with an internal floating piston (IFP), the IFP is used in the damper chamber to keep different fluids separate from one another. For example, in one embodiment, the IFP <NUM> keeps the oil separate from the nitrogen. In one embodiment, ride height adjustment is automatically made by utilizing a pump in an internal floating piston (IFP) shock configuration 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, ride height is set by changing the location of the pump head with respect to the IFP.

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 a 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> includes a helical spring <NUM>, a damper housing <NUM> with a piston and chamber (shown in further detail herein), an upper eyelet <NUM>, a lower eyelet <NUM>, and an external reservoir <NUM> having a floating piston and pressurized gas to compensate for a reduction in volume in the main damper chamber of the shock assembly as the shaft <NUM> moves into the damper body. Fluid communication between the main chamber of the damper and the external reservoir <NUM> may be via a flow channel including an adjustable needle valve. In its basic form, the damper works in conjunction with the helical spring and controls the speed of movement of the piston shaft by metering incompressible fluid from one side of the damper piston to the other as the damper travels through the main chamber, and additionally metering fluid flow from the main chamber to the reservoir, during a compression stroke and a rebound stroke.

In one embodiment, 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).

It should be appreciated that the automatically adjustable ride height capability discussed herein could be incorporated into a shock assembly <NUM> such as shown in <FIG>, or in another embodiment, into a shock assembly with more, fewer, or different components than those shown in <FIG>. For example, in one embodiment, the shock assembly <NUM> will not have a remote external reservoir <NUM>.

Further, 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 a bicycle, motorcycle, ATV, jet ski, car, snow mobile, side-by-side, and the like.

<FIG> is a section view of shock assembly <NUM> with an automatic ride height adjustment assembly as shown in accordance with an embodiment. In one embodiment, section view 2A includes some or all of the components described in <FIG> and discloses one or more additional components that are visible in the section view.

In one embodiment, shock assembly <NUM> includes main chamber <NUM> within damper housing <NUM> (of <FIG>), a damping piston <NUM> fixed to shaft <NUM>, a spring preload piston assembly <NUM>, and an optional external reservoir <NUM>.

In one embodiment, the damping piston <NUM> and shaft <NUM> are axially movable within main chamber <NUM> toward or away from upper eyelet <NUM>. For example, during a compression stroke the damping piston <NUM> and shaft <NUM> move axially through main chamber <NUM> toward upper eyelet <NUM>. In contrast, during a rebound stroke, 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> divides the main chamber <NUM> into a compression side <NUM> and a rebound side <NUM> (as shown in <FIG>). Thus, while the size of the main chamber <NUM> will remain static, the size of both the compression side <NUM> and the rebound side <NUM> will dynamically change depending upon the location of the damping piston <NUM> within the main chamber <NUM>.

In one embodiment, the damping piston <NUM> is equipped with fluid paths therethrough to permit damping 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 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 reservoir <NUM>, such as 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 reservoir <NUM>. A configuration including a description of an external reservoir, is described in <CIT>.

In one embodiment, the ride height adjustment assembly includes components such as, an IFP pump assembly <NUM> and a spring preload piston assembly <NUM> and is described in more detail herein.

In one embodiment, spring preload piston assembly <NUM> includes a fluid chamber <NUM> that is fixed with respect to damper housing <NUM> and a spring retainer <NUM> which is moveable axially along the length of damper housing <NUM>. In one embodiment, fluid can enter or leave fluid chamber <NUM> via fluid paths and fluid pumps discussed in the IFP pump assembly <NUM> discussion herein.

In one embodiment, when the amount of fluid in fluid chamber <NUM> changes, the exposed length <NUM> of spring retainer <NUM> also changes thereby changing the length of the spring preload piston assembly <NUM>. This change in the length of spring preload piston assembly <NUM> will result in a change 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 retainer <NUM> is hydraulically pushed axially along the damper housing <NUM> toward lower eyelet <NUM> increasing the exposed length <NUM> of spring retainer <NUM>. This increase in the exposed length <NUM> of spring retainer <NUM> will result in an increase in the overall 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 retainer <NUM> would move axially along the damper housing <NUM> toward upper eyelet <NUM> and into the fluid chamber <NUM> reducing the exposed length <NUM> of spring retainer <NUM>. In one embodiment, spring retainer <NUM> would move into fluid chamber <NUM> by the contraction of fluid chamber <NUM>. In one embodiment, the contraction of fluid chamber <NUM> is caused by the IFP pump assembly <NUM> removing fluid from fluid chamber <NUM>. In one embodiment, the movement of spring retainer <NUM> into fluid chamber <NUM> is caused by the force of spring <NUM> acting on spring retainer <NUM>.

In one embodiment, the decrease in the exposed length <NUM> of spring retainer <NUM> will cause a decrease in the overall length of the spring preload piston assembly <NUM>. The decrease in the length of the spring preload piston assembly <NUM> will result in a decrease of 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.

Referring now to <FIG>, a schematic diagram <NUM> of the automatic ride height adjustment assembly in a monotube shock is shown in accordance with an embodiment. In one embodiment, schematic diagram <NUM> includes main chamber <NUM> divided by the damping piston <NUM> to form a compression side <NUM> fluid chamber and a rebound side <NUM> fluid chamber. In one embodiment, schematic diagram <NUM> includes the ride height adjustment assembly including the IFP pump assembly <NUM> and the spring preload piston assembly <NUM>.

In one embodiment, the IFP pump assembly <NUM> includes components such as, bleed control valve <NUM>, a fluid reservoir <NUM>, a relief valve <NUM>, fluid flow path(s) <NUM>, check valve(s) <NUM>, an IFP fluid chamber <NUM> having a pump <NUM> therein, an IFP <NUM> separating the compression side <NUM> fluid chamber from the IFP fluid chamber <NUM> and a distance <NUM> that is the distance between the IFP <NUM> and the pump <NUM>. In one embodiment, the IFP pump assembly <NUM> is used to fill and/or empty the fluid chamber <NUM> of spring preload piston assembly <NUM>.

In one embodiment, fluid flow path <NUM> is shown between fluid reservoir <NUM> and fluid chamber <NUM> of spring preload piston assembly <NUM>. In one embodiment, check valve <NUM> is a ball spring check valve. However, it should be appreciated that 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 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 be pumped from fluid reservoir <NUM> into fluid chamber <NUM>.

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 working fluid released from fluid chamber <NUM> to the fluid reservoir <NUM> when blow-off occurs.

Referring now to <FIG>, a schematic diagram <NUM> of the automatic ride height adjustment assembly in a shock assembly <NUM> and a remote reservoir <NUM> is shown in accordance with an embodiment. In one embodiment, the ride height adjustment assembly includes the IFP pump assembly <NUM> and the spring preload piston assembly <NUM>.

In one embodiment, the components of the IFP pump assembly <NUM> are similar in <FIG> and <FIG> with the difference being in the location of the IFP pump assembly <NUM> (e.g., in the monotube shock of <FIG>, and in the remote reservoir <NUM> of <FIG>). In other words, in contrast to the location of the IFP pump assembly <NUM> of <FIG>, in schematic diagram <NUM>, the IFP pump assembly <NUM> is located in the external reservoir <NUM>.

In one embodiment, during at least a portion of the compression and/or rebound stroke fluid will move through a flow path from the main chamber <NUM> into the external reservoir <NUM>. In general, the external reservoir <NUM> will include a fluid chamber <NUM> for receiving the working fluid from the main chamber <NUM>, a compressible fluid chamber <NUM> (filled with a compressible fluid, such as for example, Nitrogen), and a reservoir IFP <NUM> to keep the working fluid separate from the compressible fluid in compressible fluid chamber <NUM>.

In one embodiment, the IFP pump assembly <NUM> is located below the compressible fluid chamber <NUM> of remote reservoir <NUM>. For example, IFP pump assembly will include a housing <NUM> with a pump <NUM> extending therethrough. One portion of pump <NUM> will be located within the compressible fluid chamber <NUM> a distance <NUM> from the reservoir IFP <NUM>. The other side of pump <NUM> will extend from housing <NUM> into compressible fluid chamber <NUM> which will include fluid flow path <NUM>, check valve(s) <NUM>, and a relief valve <NUM> (or a bleed control valve <NUM> discussed herein) configured to provide a fluid dump or rapid release of fluid from fluid chamber <NUM>.

In one embodiment, the bleed control valve and/or relief valve provides the working fluid released from fluid chamber <NUM> to the fluid reservoir <NUM> when blow-off (or a rapid release) occurs. In one embodiment, the bleed control valve and/or the relief valve can be the same type of valve or different types of valves. In one embodiment, either or both the bleed control valve and/or the relief valve can be a solenoid valve, a mechanical valve, or the like for use in a semi-active version.

In one embodiment, instead of a bleed orifice or relief valve, the IFP pump <NUM> may be engaged with the IFP <NUM> so it would act as a continuous pump that can regulate the flow with the valve (dump rapidly, etc) as described in greater detail in the "Bleed Control Valve Operation" section.

In one embodiment, the IFP pump assembly <NUM> will include another compressible fluid chamber 301b which will be separated from the non-compressible working fluid in fluid reservoir <NUM> by second IFP 318b.

In one embodiment, by locating the IFP pump assembly <NUM> in the remote reservoir <NUM>, the ride height adjustment feature can be retroactively applied to any shock that can use a remote reservoir <NUM>. In one embodiment, the ride height adjustment feature will work with all shock architectures.

Referring now to <FIG>, a schematic view of the IFP pump assembly <NUM> shown in accordance with an embodiment. In one embodiment, IFP pump assembly <NUM> includes a compressible fluid port <NUM>, compressible fluid chamber <NUM>, pump <NUM> shown with a number of parts, e.g., a post 320a to engage the IFP <NUM>, a fluid pump body 320b, and a fluid pump chamber 320c. In one embodiment, IFP pump assembly <NUM> also includes fluid reservoir <NUM>, the second IFP 318b, the second compressible fluid chamber 301b, check valve <NUM>, a bleed control valve <NUM>, fluid flow path <NUM> (to spring preload piston assembly <NUM>), a fluid pathway 125a (to external fluid reservoir <NUM>), and check tunable orifice <NUM>.

In one embodiment, post 320a sets the distance <NUM> between the pump and the IFP <NUM>. In one embodiment, post 320a is fixedly coupled with fluid pump body 320b. In one embodiment, post 320a is adjustably coupled with fluid pump body 320b and once the distance <NUM> is set the post 320a will become fixedly coupled with fluid pump body 320b.

As such, in one embodiment of a compression stroke (shown and described in more detail herein at <FIG>) when IFP <NUM> contacts post 320a both the post 320a and fluid pump body 320b will be pushed in direction C (e.g., compressed). This will cause fluid pump body 320b to move into fluid pump chamber 320c thereby causing the working fluid in fluid pump chamber 320c to be pumped through fluid flow path <NUM> and into spring preload piston assembly <NUM>.

In contrast, in one embodiment of a rebound stroke (shown and described in more detail herein at <FIG>) when IFP <NUM> moves away from post 320a (e.g., in a direction opposite to direction C) both the post 320a and fluid pump body 320b will also move in a rebounding direction (e.g., the direction opposite to direction C). This will cause fluid pump body 320b to withdraw from fluid pump chamber 320c allowing working fluid to refill the fluid pump chamber 320c.

In one embodiment, the fluid pump chamber 320c will be refilled from some amount of fluid drawn back from fluid flow path <NUM> and from the fluid in fluid reservoir <NUM> via check tunable orifice <NUM>. In one embodiment, the fluid pump chamber 320c will only be refilled from the fluid in fluid reservoir <NUM> via check tunable orifice <NUM>.

In one embodiment, the distance <NUM> between post 320a and the IFP <NUM> is set based on the proper SAG of the vehicle. For example, when the vehicle is in the proper SAG configuration and load, the post 320a will be in a location such that the normal operation of the shock assembly <NUM> will provide little to no interactions between IFP <NUM> and post 320a to keep the length of spring preload piston assembly <NUM> relatively constant.

In contrast, when the vehicle is loaded with extra weight, the vehicle will be riding low (e.g., below the established SAG) and the IFP <NUM> will contact post 320a during some or all of the compression stroke. As such, when the vehicle is riding low, the IFP pump assembly <NUM> will be pumping fluid into spring preload piston assembly <NUM> which will increase the overall length of spring preload piston assembly <NUM> and shock assembly <NUM> which will increase the vehicle ride height.

In one embodiment, when the vehicle is lightly loaded (or when the extra weight is removed, the vehicle will be riding high (e.g., above the established SAG) and the IFP <NUM> will not be contacting post 320a. As such, when the vehicle is riding high, the bleed control (either passive or semi-active as described herein) will allow fluid flow out of spring preload piston assembly <NUM>. The reduction of fluid in spring preload piston assembly <NUM> will reduce the length of spring preload piston assembly <NUM> which will reduce the overall length of spring preload piston assembly <NUM> and shock assembly <NUM> which will reduce the vehicle ride height.

In one embodiment, check tunable orifice <NUM> is used to control flow of the non-compressible working fluid from fluid reserve <NUM> into fluid pump chamber 320c. In one embodiment, check tunable orifice <NUM> is used to tune the limit of reflow on consecutive hits (or pump activations). For example, if the check tunable orifice <NUM> is tuned to fill slowly, then if a number of compression strokes are quickly made, the first compression stroke would pump a large amount of fluid from fluid pump chamber 320c into spring preload piston assembly <NUM>. However, the next few quick compression strokes would find a lesser amount of fluid in fluid pump chamber 320c due to the flow restrictions from fluid reservoir <NUM> into fluid pump chamber 320c. In one embodiment, by adjusting the check tunable orifice <NUM>, the encounter of a rumble strip (or the like) would not cause an over-pumping situation into spring preload piston assembly <NUM>.

In one embodiment, the compressible fluid is Nitrogen, air, or the like. In one embodiment, the working fluid is a non-compressible hydraulic fluid.

Referring now to <FIG>, a section view of the automatic ride height adjustment assembly with a focus on the IFP pump assembly <NUM> operating in a compression stroke is shown in accordance with an embodiment. In general, the components are the same in <FIG> with the difference being in the flow direction and/or paths taken by the fluid. As such, the discussion of <FIG> and <FIG> will focus on the movement and flow directions of the components shown and discussed with respect to <FIG>.

In one embodiment of a compression stroke, when IFP <NUM> contacts post 320a both the post 320a and fluid pump body 320b will be pushed in direction C. This will cause fluid pump body 320b to move into fluid pump chamber 320c thereby causing the working fluid in fluid pump chamber 320c to be pumped through fluid pathway <NUM> as shown by arrows <NUM> and into fluid chamber <NUM> of spring preload piston assembly <NUM>.

In one embodiment, check valve <NUM> will keep the flow from returning from spring preload piston assembly <NUM> until an adjustment (either a passive or semi-active adjustment) is made to bleed control valve <NUM>. In one embodiment, if there is a relief flow from the relief valve <NUM>, it will follow relief flow path <NUM> back to fluid reservoir <NUM>.

In <FIG>, a section view of the automatic ride height adjustment assembly with a focus on the IFP pump assembly <NUM> operating in rebound is shown in accordance with an embodiment.

In one embodiment of a rebound stroke when IFP <NUM> moves away from post 320a, e.g., in direction R, both the post 320a and fluid pump body 320b will also move in a rebounding direction (e.g., the direction opposite to direction C). This will cause fluid pump body 320b to withdraw from fluid pump chamber 320c allowing working fluid to refill the fluid pump chamber 320c.

In one embodiment, the fluid pump chamber 320c will be refilled from some amount of fluid drawn back from fluid flow path <NUM> and from the fluid path <NUM> that flows from fluid reservoir <NUM> via check tunable orifice <NUM>. In one embodiment, the fluid pump chamber 320c will only be refilled from the fluid path <NUM> that flows from fluid reservoir <NUM> via check tunable orifice <NUM>.

In one embodiment, check valve <NUM> will keep the flow from returning from spring preload piston assembly <NUM> until an adjustment (either a passive or semi-active adjustment) is made to bleed control valve <NUM>.

In one embodiment, the ride height adjustment feature does not change the damping values for different preloads (e.g., part of the initial SAG settings). For example, the pump <NUM> will cause the suspension to rise by pumping the fluid into the fluid chamber <NUM> causing the fluid chamber <NUM> to expand and move the spring retainer <NUM> to adjust the suspension back toward the correct geometric ride height (e.g., the established SAG for the vehicle). While this adjustment will not relieve the load on the now somewhat compressed helical spring <NUM>, it will also not increase the pressure in the damping chamber. As such, the operation of the damping chamber in both rebound and compression, to include the fluid pressures in the damping chamber, would not be affected by the automatic ride height adjustment.

In one embodiment, using the semi-active configuration of bleed control valve <NUM>, the fluid can be dumped from the fluid chamber <NUM> to allow a vehicle to drop to a lower height. For example, as a vehicle is loaded with extra weight, the ride height would be lowered due to the extra weight, but once the vehicle was put into motion the automatic ride height adjustment will return the vehicle ride height back to the established SAG for the vehicle, e.g., by adding fluid to the fluid chamber <NUM>. In one embodiment, when the vehicle is stopped (or parked for an amount of time), the semi-active system would maintain the correct ride height by locking out the flow from fluid chamber <NUM> to prevent ride height bleed down.

However, in one embodiment, when the vehicle is stopped and is ready to be unloaded, the semi-active pressure release could be used to release the fluid from fluid chamber <NUM> causing the suspension height to return to the lowered state.

Thus, during loading -the suspension would be lowered (e.g., moving a wheel well closer to the tire), during vehicle operation -the automatic ride height adjustment would automatically return the ride height to SAG (e.g., moving the wheel well back away from the tire), and then once the vehicle was stopped, the semi-active system would maintain the ride height by locking out the system. However, if it were time to unload, or otherwise desired, the semi-active bleed control valve <NUM> would release the fluid from fluid chamber <NUM> which would return the vehicle to the lowered suspension state.

In one embodiment, a passive version of bleed control valve <NUM> could be used on a motorcycle suspension to allow a rider to lower the ride height at any time (or a number of different times) on a given ride. For example, the rider could have a ride height setting (e.g., an established riding SAG) that is good for riding, but a bit high when the bike is stopped (such as at a light, stop sign, being parked, etc.). By using a passive bleed control valve <NUM>, the rider could release the fluid from fluid chamber <NUM> and lower the ride height manually when the bike is stopped. In one embodiment, the rider might even utilize two different SAG settings, e.g., a riding SAG, and a lower stopped SAG.

In one embodiment, the semi-active version of bleed control valve <NUM> would automatically adjust the ride height via a motion sensing system, where the ride height would be automatically lowered when a stop in forward motion was detected. For example, in the automated setup, the monitoring system could release the fluid from fluid chamber <NUM> when the bike is slowing, when the bike is stopped, after the bike is stopped for a given period of time, when the bike is stopped for a given period of time and the throttle is also not engaged, when the bike is stopped and is also taken out of gear, turned off, and the like.

In one embodiment, the system automation could include terrain: E. , on a road at a stop or when the vehicle drops below x-miles per hour; off-road when the vehicle is stopped and the clutch is engaged; off-road when the vehicle is stopped and the throttle is disengaged; off-road when the vehicle is stopped and the vehicle gearbox is in neutral; etc. Although a motorcycle is used in the example, the same operation could be performed in any number of different vehicles.

In one embodiment, the passive and/or semi-active configuration can be used to release the fluid from fluid chamber <NUM> and lower the vehicle to allow for easier exit, entrance or the like. For example, in one embodiment, bleed control valve <NUM> could be used to dump the fluid out of the fluid chamber <NUM> and lower the vehicle for an extended period of time, even while the vehicle is in operation, to reduce the ride height for purposes such as overhead clearance and the like. For example, if the vehicle is a loaded cargo van, the bleed control valve <NUM> could be used to change the ride height of the van could from the SAG to the lower ride height while moving through an underpass, an overhang, a parking garage, and the like. Moreover, once the height limiting obstacle has been cleared, the bleed control valve <NUM> could be passive and/or semi-actively reengaged thereby causing the automatic ride height system to return the vehicle to its SAG.

According to the invention, since the working fluid is pulled from fluid reservoir <NUM>, the automatic ride height adjustment system will not pull oil from the main chamber <NUM> of shock assembly <NUM>. As such, the operation of the damping portion of shock assembly <NUM> will not be affected by the fluid that is pumped into or released from the fluid chamber <NUM>.

In one embodiment, the distance <NUM> between the IFP <NUM> and the pump <NUM> is preset at the factory. In one embodiment, the distance <NUM> between the IFP <NUM> and the pump <NUM> is user adjustable to set a SAG ride height. For example, as shown in <FIG>, in one embodiment, pump <NUM> includes a threaded portion <NUM> such that the rotation of pump <NUM> will adjust the distance <NUM> between the IFP <NUM> and the pump <NUM>.

In one embodiment, the distance <NUM> between the pump <NUM> and the IFP <NUM> can be set to <NUM> from the factory, for example in contact or very close to being in contact, in order to displace the maximum amount of fluid into the fluid chamber <NUM>.

In one embodiment, this close distance <NUM> setting would be used in a semi-active configuration. For example, if riding low and using the semi-active configuration, the bleed control valve <NUM> could be closed in order to rapidly raise vehicle ride height. In contrast, when riding high and using the semi-active configuration, the bleed control valve <NUM> can be opened slightly to adjust to desired ride height e.g., return to SAG.

Thus, if the location of the distance <NUM> between the IFP <NUM> and the pump <NUM> is changed, the ride height would also be changed. In so doing, changing distance <NUM> would result in a different ride height SAG setting.

In one embodiment, the distance <NUM> between the pump <NUM> and the IFP <NUM> will be set based an amount of suspension travel. For example, the IFP <NUM> to pump <NUM> distance <NUM> could be <NUM>% of the suspension travel when the shock assembly <NUM> was at SAG. In this example, the IFP <NUM> would only engage the pump <NUM> when the suspension was using more than <NUM>% of travel.

As the shock assembly <NUM> is in operation, whenever the IFP <NUM> engages the pump <NUM>, the pump <NUM> will displace an amount of fluid into the fluid chamber <NUM>. The fluid pumped into the fluid chamber <NUM> will cause the expansion of the fluid chamber <NUM>. In one embodiment, this expansion will move the spring retainer <NUM> upward to adjust the suspension back toward the correct geometric ride height (e.g., the established SAG for the vehicle). While this adjustment will not relieve the load on the now somewhat compressed helical spring <NUM>, it will also not increase a fluid pressure in the damping chamber.

In one embodiment, the pumping of fluid into the fluid chamber <NUM> will continue while the IFP <NUM> is interacting with the pump <NUM>. Once the IFP <NUM> disengages from the pump <NUM>, the pump <NUM> will no longer add fluid to the fluid chamber <NUM> and the ride height will no longer be raised. For example, in one embodiment, the IFP <NUM> will disengage from the pump <NUM> after the suspension travel is reduced to only <NUM>%.

In one embodiment, the fluid in the fluid chamber <NUM> is subject to a number of different operational configurations. For example, in the passive system mode, the fluid will be released at a predefined rate from the fluid chamber <NUM> to the fluid reservoir. In the semi-active system mode, the fluid will be, locked into the fluid chamber <NUM>, slowly released from the fluid chamber <NUM> into the fluid reservoir, or allowed to rapidly return to the reservoir through the flow paths used to provide the fluid from the pump <NUM> to the fluid chamber <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.

For example, as shown in <FIG>, <FIG>, and <FIG> when weight is added to the vehicle the ride height will be reduced as the suspension spring <NUM> is compressed a small amount (axial spring length <NUM> is shortened) and the damping piston <NUM> moves to a new resting location within main chamber <NUM> closer to upper eyelet <NUM> which will move IFP <NUM> toward pump <NUM> reducing the distance <NUM>.

In one embodiment, during normal suspension operation (as opposed to a significant suspension event which may exceed the blow off pressure for relief valve <NUM>), for each compression movement of the damping piston (during suspension use), the IFP <NUM> will make contact with pump <NUM> causing fluid to be pumped through fluid flow path <NUM> and into the fluid chamber <NUM>. This addition of fluid into fluid chamber <NUM> will cause the fluid chamber <NUM> to expand which will cause spring retainer <NUM> to move axially along the damping chamber increasing the exposed length <NUM> of spring retainer <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>.

In one embodiment, as long as the shock assembly <NUM> is riding low, IFP <NUM> will continue to contact pump <NUM> during compression strokes. This will cause fluid to continue to be pumped into fluid chamber <NUM>, which would further expand the size of fluid chamber <NUM> and again cause the spring retainer <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 automatically increased again.

In one embodiment, the automatic pumping process would continue for each compression stroke. However, as the ride height increases, the total amount of fluid pumped by the IFP <NUM> will be reduced as the IFP <NUM> will both push less on pump <NUM> during compression strokes.

In one embodiment, the pumping of fluid into fluid chamber <NUM> would continue at an incrementally slower pace until the shock assembly <NUM> returned to SAG, at which point the IFP <NUM> would no longer be contacting pump <NUM> during normal compression strokes.

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 spring length <NUM>. In this example, once the maximum size (or capacity) of fluid chamber <NUM> was reached, more fluid would still be being pumped by pump <NUM> along fluid flow 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 along fluid flow path <NUM> would be released through the fluid relief valve <NUM> and returned to fluid reservoir <NUM>.

In one embodiment, even if fluid chamber <NUM> was not full, if the shock assembly <NUM> were to encounter a significant event causing a large compression, some amount of the fluid pumped through fluid flow path <NUM> would also be dumped through the fluid relief valve <NUM>.

In one embodiment, when the 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.

For example, using <FIG>, <FIG>, and <FIG>, the increase of the shock assembly <NUM> length due to the removed weight will cause the damping piston <NUM> and shaft <NUM> to move to a new resting location within main chamber <NUM> further away from upper eyelet <NUM> which will also move IFP <NUM> away from pump <NUM> increasing the distance <NUM>.

In one embodiment, during normal suspension operation (as opposed to a significant suspension event which may exceed the blow off pressure for relief valve <NUM>, or a parked vehicle where the fluid in the fluid chamber <NUM> may be held to maintain a parked ride height), fluid will be released out of the fluid chamber <NUM> by bleed control valve <NUM>. Once again, since fluid will only be pumped into the fluid chamber <NUM> when the IFP <NUM> contacts pump <NUM>. Since this will initially not occur, due to the high ride configuration, the fluid will continue to flow out of the fluid chamber <NUM> causing the movement of spring retainer <NUM> into fluid chamber <NUM>.

In one embodiment, the movement of spring retainer <NUM> into fluid chamber <NUM> will decrease the exposed length <NUM> of spring retainer <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>.

In one embodiment, the fluid chamber <NUM> would continue to contract in size as the fluid drained due to the spring retainer <NUM> being pushed back into the fluid chamber <NUM> by the spring force of spring <NUM>.

In one embodiment, the process of draining fluid from fluid chamber <NUM> would continue to occur until the originally established ride height is reached, or until the IFP <NUM> started to contact pump <NUM>, and then began pumping fluid back into fluid chamber <NUM>. In so doing, the vehicle will automatically return to the established SAG for the vehicle.

Thus, embodiments provide the ability to automatically maintain the ride height (e.g., the established SAG) of a vehicle. For example, a rider is utilizing a snowmobile and has the suspension ride height SAG tuned for a single rider (e.g., <NUM> lbs. At some point, the rider invites a passenger along to also enjoy the sled ride. However, with two riders on the sled, the passenger weight is now (<NUM> lbs. ) and the SAG for the vehicle is lowered due to the extra weight.

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. 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 would be higher than the SAG and the system would automatically or manually 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 established SAG. 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 vehicle 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 (e.g., ride height increased by <NUM>-which may or may not be equivalent to the change in shock assembly <NUM> length due to any angles in the vehicle suspension). 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 established SAG was reached. 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>.

In one embodiment, the automatic ride height assembly can also be used to provide a bottom out control. That is, the bottom out control can be provided by tuning the surface area of pump <NUM> and/or adjusting the size of an orifice leaving the pump <NUM> and going to the fluid chamber <NUM> thereby creating larger rod reaction forces when IFP <NUM> engages pump <NUM>. For example, once the IFP <NUM> engages the pump <NUM>, the pump <NUM> head cross-sectional area is a function of how much force it takes to move the pump <NUM>. By changing the pump <NUM> head cross-sectional area, the amount of force needed to move the pump <NUM> will be changed.

In one embodiment, one or more check tunable orifice(s) <NUM> in the automatic ride height adjustment system could be opened, widened, narrowed, or closed to provide different pressures necessary to move the fluid from the pump <NUM> through the fluid chamber <NUM> flow path to the fluid chamber <NUM>. By adjusting the flow pressure required by the pump <NUM> to move the fluid through the flow path to the fluid chamber <NUM>, bottom out control can be obtained. For example, bottom out force will increase as preload flow pressure increases. Moreover, by using active valves, automated orifice adjustment, and the like, the automatic ride height adjustment system can provide bottom out control that can be adjusted on the fly. In one embodiment, the bottom out control will change the pressures in the damping chamber.

In one embodiment, relief valve <NUM> and/or bleed control valve <NUM> is configured to provide a rapid pressure dump. In one embodiment, relief valve <NUM> and/or bleed control valve <NUM> is configured to provide a rapid pressure dump or a lockout for fluid chamber <NUM> to prevent a bleed down. In one embodiment, the relief valve <NUM> and/or bleed control valve <NUM> provides the working fluid to the fluid reservoir when blow-off occurs.

In one embodiment, any, some, or all of the orifice sizes in the flow path for the automatic ride height adjustment assembly (including check valve <NUM>, check tunable orifice <NUM>, relief valve <NUM> and/or bleed control 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, the size of one or more orifice in the flow path can be automatically adjusted based on the terrain. For example, on a roadway, the orifice could be at a wider state since the suspension will not likely be encountering a lot of significant travel. In contrast, if the vehicle was operating in a rough environment (e.g., lots of bumps, whoops, or other large and consistent suspension travel events), one or more of the orifices could be reduced (or closed) such that the pump would not provide the same amount of fluid into the fluid chamber to reduce any unnecessary ride height adjustments, e.g., which would also cause unneeded additional spring preload.

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 <NUM> 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, one or more fluid flow path(s) <NUM> open or closing, check valve <NUM>, the blow-off setting of relief valve <NUM>, the size of check tunable orifice <NUM>, 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 relief valve <NUM> and/or bleed control valve <NUM>. In one embodiment, the released fluid will be released back to the fluid reservoir <NUM>.

In one embodiment, any, some, or all of the orifice sizes and/or the flow paths for the automatic ride height adjustment assembly (including check valve <NUM>, check tunable orifice <NUM>, relief valve <NUM> and/or bleed control valve <NUM>, and the like) are non-active valves, e.g., a manual valve that may be adjustable but is not electronically adjustable.

In one embodiment, any, some, or all of the orifice sizes and/or the flow paths for the automatic ride height adjustment assembly (including check valve <NUM>, check tunable orifice <NUM>, relief valve <NUM> and/or bleed control valve <NUM>, and the like) are automatically adjustable such as via the use of an active valve <NUM>.

In one embodiment, any, some, or all of the orifice sizes and/or the flow paths for the automatic ride height adjustment assembly (including check valve <NUM>, check tunable orifice <NUM>, relief valve <NUM> and/or bleed control valve <NUM>, and the like) are a mix of active and non-active valves.

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 working fluid through orifice <NUM>. In contrast, when active valve <NUM> is partially closed, a second flow rate of the working 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 working 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 <CIT>, as further example of different types of "electronic" or "active" valves). Thus, the active valve <NUM>, can be used to meter the 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 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 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 damping 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> and that patent is incorporated by reference herein in its entirety.

While transducers located at the suspension damper measure piston rod velocity (piston rod velocity 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> and <FIG>, or in another embodiment, into a shock assembly with more, fewer, or different components than those shown in <FIG> and <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 working fluid therein;
a damping piston (<NUM>) coupled to a piston shaft (<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:
an internal floating piston (IFP) pump assembly (<NUM>); and
a spring preload piston assembly (<NUM>);
characterized in that said IFP pump assembly (<NUM>) comprises:
an IFP (<NUM>) to separate said working fluid from a compressible fluid in an IFP fluid chamber (<NUM>);
a pump (<NUM>) fixedly located within said IFP fluid chamber (<NUM>);
a fluid reservoir (<NUM>) to provide said working fluid to said pump (<NUM>), said working fluid in said fluid reservoir fluidly separated from said working fluid in said main chamber (<NUM>); and
a fluid pathway (<NUM>) to provide said working fluid from said pump to said spring preload piston assembly.