WO2025015169A1

WO2025015169A1 - Position selectable damper

Info

Publication number: WO2025015169A1
Application number: PCT/US2024/037608
Authority: WO
Inventors: Rudolf Gruber; Michael Francis Anthony ADAMOVSKY
Original assignee: Multimatic Inc; MULTIMATIC PATENTCO LLC
Current assignee: Multimatic Inc; MULTIMATIC PATENTCO LLC
Priority date: 2023-07-13
Filing date: 2024-07-11
Publication date: 2025-01-16
Anticipated expiration: 2026-01-13

Abstract

A vehicular damper with a piston reciprocating within a damper body during compression and rebound strokes has variable hydraulic fluid compression and rebound volumes on opposite sides of the piston. Arrays of compression valves connected in parallel and rebound valves connected in parallel resist hydraulic flow during the compression stroke in a compression valve active mode, and during the rebound stroke in a rebound valve active mode and provide minimal resistance to hydraulic flow respectively during the rebound stroke in a compression valve passive mode, and during the compression stroke in a rebound valve passive mode. A hydraulic fluid passageway conducts hydraulic fluid through the valves and a return tube. A sensor array senses piston location. A controller progressively opens and closes selected valves in the arrays of compression and rebound valves to adjust resistance to hydraulic flow dependent upon the sensed piston location during the compression and rebound strokes.

Description

POSITION SELECTABLE DAMPER

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Application No. 63/513,471 filed on July 13, 2023, and is incorporated herein by reference.

TECHNICAL FIELD

[0002] This application relates to the field of dampers, and particularly to the field of vehicular dampers.

BACKGROUND

[0003] A typical vehicular damper comprises a piston mounted on a piston rod which reciprocates in hydraulic fluid within a damper body. Each wheel of a vehicle is typically provided with a damper which works along with a spring to provide the vehicular suspension system. The spring reacts to motion of the wheel on a driving surface and the damper attenuates the induced motion to prevent the vehicle from bouncing up and down by absorbing energy and returning the spring to its neutral loaded or ride height position. When a velocity is inputted to the damper via the piston rod in what is generally referred to as a compression, bump or jounce stroke, the piston is forced further into the damper body against resistance of hydraulic fluid thus generating a velocity dependent resistive force. The terms compression, bump and jounce may generally be used interchangeably. Then the piston is pulled back towards its original position by the vehicle spring in what is generally referred to as a rebound stroke against resistance of the hydraulic fluid in the opposite direction.

[0004] During bump and rebound strokes, hydraulic fluid flows through one or more orifices in the piston to generate resistive forces dictated by the characteristics of the orifices. The passage of hydraulic fluid through the orifices generates heat which is dissipated to release the energy of the piston movement.

[0005] Off-road vehicles negotiate challenging terrain and require more robust suspension systems than typical on-road vehicles. The position sensitive damper facilitates staged damping resistance so that lesser resistance is generated during a partial compression stroke and maximum resistance is generated during a full damper compression stroke. This both controls the motion of the vehicle and prevents damage to the damper and other

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SUBSTITUTE SHEET (RULE 26) suspension components. During the rebound stroke a staged increase in damping force is typically also implemented. The extremely bumpy conditions of off-road driving generates considerable heat in the damper which must be dissipated quickly.

[0006] Traditional position sensitive dampers are constructed with a cylindrical damper body enclosing a piston with an attached piston rod. In essentially all similar damper systems, hydraulic fluid flows under pressure from the volume on one side of the piston to the volume on the other side of the piston. A reservoir for the hydraulic fluid is typically provided between these volumes to take into account the fluid volume displaced by the piston rod and the changing volume of the hydraulic fluid as it heats and cools.

[0007] A standard prior art position sensitive damper (100), as illustrated in FIGS. 1 A-1E, comprises a robust cylindrical damper body (102), piston (104) and piston rod (106). In addition to the hydraulic fluid flow through the piston (104) from the higher-pressure volume to the lower pressure volume during compression (FIGS. 1C, ID) and rebound (FIGS. 1A, IB) strokes as in most automotive dampers, the position sensitive damper (100) provides for additional exit of hydraulic fluid from the damper body (102) through orifices (108, 110, 112, 114, 116) spaced longitudinally along the wall of the damper body (102). These spaced orifices are arranged along the length of the damper body (102) between the neutral piston position and the closed end of the damper body (102). The number of orifices determines the number of possible pressure zones. Each orifice connects to a return tube passageway (119) which transmits hydraulic fluid back to the lower pressure volume. Hydraulic fluid flow may be controlled by valves (128). In FIGS. 1A-1E, a dark disk (120) beside a valve (128) indicates that the valve (128) is closed, while a white disk (122) indicates that the valve (128) is open. The dark and white disks (120, 122) represent a valve condition rather than a physical element. A hydraulic fluid reservoir (118) is provided. In the low-pressure zone, which is typically the mid stroke or vehicle ride height zone, the hydraulic fluid can flow through the piston orifices and several of the orifices (108, 110, 112, 114, 116) spaced along the damper body (102) (see FIGS. 1A, ID). As the piston (104) travels towards the full damper compression stroke (FIG. IB) it passes each of the spaced orifices sequentially reducing the number of fluid flow passages which increases the pressure at the leading edge of the piston (104) and thus the damper force. Ultimately, at a certain distance from the fully compressed, or fully extended, position the hydraulic fluid can only flow through the piston (104) thus generating the highest damping force (see FIGS. IB, 1C).

[0008] A position sensitive damper provides a number of pressure zones. This could be three, five or some other number of zones. To illustrate, a position sensitive damper

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SUBSTITUTE SHEET (RULE 26) with three zones has two spaced orifices arranged along the length of the damper body. With the piston in a neutral position, its piston orifice and the two spaced orifices are open to permit the maximum hydraulic fluid flow and to present minimum resistance to such flow. When a short bump stroke occurs, all three orifices may remain open during both the bump stroke and the rebound stroke. In the case of a longer bump stroke, the first spaced orifice may be blocked by the piston. Since the flow of hydraulic fluid is now restricted to two orifices, the pressure of the hydraulic fluid in the high pressure volume increases. The damper has transitioned from a first, lowest pressure zone to a second, higher pressure zone.

[0009] If the piston is urged to travel further during a compression stroke, the second spaced orifice may in turn be blocked by the piston leaving only the single piston orifice open. This creates the third pressure zone which resists movement of the piston to a still greater extent since only a single orifice is open to allow escape of hydraulic fluid from the higher pressure volume of the damper body.

[0010] In the rebound direction, a similar arrangement may be implemented with a second set of spaced orifices or the hydraulic fluid may only flow through the piston orifice. In the case of multiple spaced rebound orifices, typically check functions are used for all flow passages to only allow flow through the dedicated spaced bump or rebound orifices.

[0011] The number of orifices and return tubes increases with each additional zone.

The zones are fixed once the damper is constructed as their physical location is determinative of their response. Once the zones are selected when the damper is constructed, they may not be altered. In addition, each zone with its attendant fluid passageway adds weight and may increase the size of the damper as the damper’s external dimensions increase.

SUMMARY

[0012] Accordingly, it would be advantageous to create a damper which permits changes to the pressure zones with a single construction. It would also be advantageous to reduce the complexity by decreasing the number of passageways required to cycle hydraulic fluid from the high-pressure volume to the low-pressure volume in the damper body. In addition, it would be useful to provide effective cooling of the damper hydraulic fluid as close as possible to the flow restricting orifices which generate the heat.

[0013] An advance in position sensitive damping has been developed which may be referred to as position selective or position selectable damping. Rather than using multiple rebound and compression tubes located at various points along the length of the damper, a

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SUBSTITUTE SHEET (RULE 26) single passageway is employed for fluid to exit from the damper during compression. Hydraulic fluid passes via the single passageway through an array of specially designed spool valves, such as those described in US 8,235,186, US 8,800,732, and US 11,733,940. This results in the hydraulic fluid moving from an area of high pressure to an area of lower pressure. Such spool valve damper technology offers unparalleled precision of force-velocity (“F-V”) characteristics and provides cavitation-proof operation in extreme conditions.

[0014] The spool valves are arranged within the top and bottom housings of the damper, outside of the damper body, with the low-pressure fluid preferably being immediately cooled by finned radiant heat exchanger tubes to maximize the radiation and dissipation of the converted kinetic energy. This arrangement keeps the hydraulic fluid cooler than in conventional position sensitive dampers in thermally critical spots like the solid piston and rod seal areas. These innovative position selectable dampers can perform in the most extreme conditions of temperature and terrain without overheating. Use of a high-capacity, low pressure side reservoir assures insensitivity to temperature and little effect on vehicle spring rate at each wheel.

[0015] A range of force-velocity curves with customizable transition positions is created by actively controlling the spool valves. By linking the control of the spool valves to a detected position of the piston rather than having the function of the damper depend upon physically pre-set pressure zones, a number of advantages arise. For example, factory tuned settings are loaded as a default, but are adjustable. A range of different configurations for terrain, ambient conditions, vehicle mass, vehicle set up including carrying load, suspension spring stiffness, tire selection, etc., or user preferences can be defined. When the damper system is so configured, the user may even adjust pressure zone transition points from within the vehicle using a vehicle-mounted human interface module, or wirelessly, for example using a mobile software application loaded on a hand-held smartphone.

[0016] A vehicular damper may include a cylindrical damper body, a piston rod connected at a first end external to the damper body to an unsprung mass or a sprung mass of a vehicle, the piston rod connected at a second end internal to the damper body to a piston, the piston adapted to reciprocate within the damper body during compression strokes and rebound strokes, a variable hydraulic fluid compression volume within the damper body limited by a position of a compression face of the piston, a variable hydraulic fluid rebound volume within the damper body limited by a position of a rebound face of the piston, an array of compression valves connected in parallel adapted to provide resistance to the passage of hydraulic fluid during the compression stroke in a compression valve active mode and to provide minimal

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SUBSTITUTE SHEET (RULE 26) resistance to a passage of hydraulic fluid during the rebound stroke in a compression valve passive mode, an array of rebound valves connected in parallel adapted to provide resistance to the passage of hydraulic fluid during the rebound stroke in a rebound valve active mode and to provide minimal resistance to the passage of hydraulic fluid during the compression stroke in a rebound valve passive mode, a hydraulic fluid passageway which conducts hydraulic fluid from the compression volume through the compression valves in the compression valve active mode to a low pressure return tube and through the rebound valves in the rebound valve passive mode to the rebound volume during the compression stroke, and from the rebound volume through the rebound valves in the rebound valve active mode to the low pressure return tube and through the compression valves in the compression valve passive mode to the compression volume during the rebound stroke, an array of sensors spaced longitudinally along an outer face of the damper body adapted to sense a location of the piston, and a controller adapted to progressively close selected valves in the arrays of compression valves and rebound valves to increase the resistance to hydraulic fluid flow dependent upon the sensed piston location during the compression stroke and the rebound stroke respectively.

[0017] In a further aspect, the sensors are Hall-effect sensors adapted to sense a piston-mounted magnet.

[0018] In a further aspect, the arrays of compression valves and rebound valves comprise spool valves.

[0019] In a further aspect, the array of compression valves comprises three spool valves.

[0020] In a further aspect, the array of rebound valves comprises two spool valves.

[0021] In a further aspect, an exterior of the low-pressure return tube is provided with an array of fins to air cool the hydraulic fluid.

[0022] In a further aspect, each of the compression valves and rebound valves is adapted to close electronically under the control of a solenoid valve.

[0023] In a further aspect, each of the compression valves and rebound valves may be closed within 3 milliseconds.

[0024] In a further aspect, each compression valve and rebound valve is a spool valve with a pressure pin adapted to block hydraulic fluid flow when electronically closed.

[0025] In a further aspect, the controller is programmed to select the piston positions where the selective closure of any one of the compression valves occurs to vary pressure response zones.

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SUBSTITUTE SHEET (RULE 26) [0026] In a further aspect, the pressure response zones may be varied to adapt to conditions of a vehicle and of driving surfaces.

[0027] In a further aspect, the pressure response zones may be varied remotely by means of one of a vehicle-mounted human interface module and a mobile computer software application loaded on a hand-held smartphone.

[0028] In a further aspect, each of the compression valves and rebound valves is identical.

[0029] In a further aspect, any one of the compression valves and rebound valves may differ from another one of the compression valves and rebound valves.

[0030] In a further aspect, one compression valve remains passive during the rebound stroke and one rebound valve remains passive during the compression stroke.

[0031] Typically, one valve during each of the rebound and compression strokes remains passive as shutting off all valves at once would hydraulically lock the damper system. It is also possible to leave one valve open at all times since each of the valves in each of the arrays of bump valves and rebound valves may have different characteristics from the other valves. Adjustability may be increased by always leaving different selected valves open in different situations.

[0032] These and other features may be best understood from the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIGS. 1A to ID are elevation, schematic, cross-sectional views of a prior art position sensitive damper.

[0034] FIG. IE is a perspective view of the exterior of a prior art position sensitive damper.

[0035] FIG. 2 is a partial, perspective, exterior view of a representative position selectable damper.

[0036] FIG. 3 is a partial, elevation, cross-sectional view of the position selectable damper of FIG. 2.

[0037] FIG. 4 is a perspective view of the position selectable damper of FIG. 2 including a reservoir.

[0038] FIG. 5 is a partial, elevation, schematic, cross-sectional view of the position selectable damper with a controller and sensor array.

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SUBSTITUTE SHEET (RULE 26) [0039] FIG. 6 is a schematic representation of various pressure zones in the position selectable damper also showing handheld and vehicle mounted controller input devices.

[0040] FIG. 7A illustrates a solenoid valve in an elevation, exterior view.

[0041] FIG. 7B is a chart illustrating typical solenoid valve response times for a particular solenoid valve configuration.

[0042] FIG. 7C is an elevation, cross-sectional view of a solenoid valve showing hydraulic fluid flow in open and closed valve positions.

[0043] FIG. 8A is a cross-sectional view of a compression or a rebound spool valve and an elevation view of a solenoid valve both in an open position showing hydraulic fluid flow.

[0044] FIG. 8B is a cross-sectional view of a compression or a rebound spool valve and an elevation view of a solenoid valve both in a closed position showing hydraulic fluid flow.

[0045] FIG. 9A illustrates a conventional position sensitive damper football curve and a conventional position sensitive damper.

[0046] FIG. 9B illustrates position selectable damper football curves and a position selectable damper.

DETAILED DESCRIPTION

[0047] A representative position selectable damper is illustrated in FIGS. 2 to 8B. Referring to FIGS. 2 to 5, a vehicular damper (1) comprises a cylindrical damper body (3). A piston rod (5) is connected conventionally at a first end (7) external to the damper body (3) to an unsprung mass (6) or a sprung mass (8) of a vehicle (represented schematically). The piston rod (5) is connected at a second end (9) internal to the damper body (3) to a piston (11). The piston (11) is adapted to reciprocate within the damper body (3) during compression strokes and rebound strokes of the damper (1). A variable hydraulic fluid compression volume (13) within the damper body (3) is limited by a position of a compression face (15) of the piston (11). A variable hydraulic fluid rebound volume (17) within the damper body (3) is limited by a rebound face (19) of the piston (11).

[0048] As the volume of hydraulic fluid in the hydraulic fluid compression volume (13) increases, the volume of hydraulic fluid in the hydraulic fluid rebound volume decreases proportionately. As a corollary, as the volume of hydraulic fluid in the hydraulic fluid

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SUBSTITUTE SHEET (RULE 26) compression volume decreases, the volume of hydraulic fluid in the hydraulic fluid rebound volume increases proportionately.

[0049] An array of compression valves (21) are connected in parallel. During the compression stroke, the compression valves (21) are adapted to provide resistance to passage of hydraulic fluid in a compression valve active mode. During the rebound stroke, the compression valves (21) provide minimal resistance to the passage of hydraulic fluid in a compression valve passive mode. The array of compression valves (21) may comprise two, three or more valves.

[0050] An array of rebound valves (23) are connected in parallel. During the rebound stroke, the rebound valves (23) are adapted to provide resistance to the passage of hydraulic fluid in a rebound valve active mode. During the compression stroke, the rebound valves (23) provide minimal resistance to the passage of hydraulic fluid in a rebound valve passive mode. Although any suitable number of rebound valves (23) may be used, it has been found that having two rebound valves (23) in combination with three compression valves (21) is particularly functional.

[0051] Although multiple conventional valve types may be used in a position selectable damper, it is particularly beneficial to employ spool valves as taught in US 8,235,186, US 8,800,732, and US 11,733,940, the teachings of which are incorporated herein. In these spool valves, a coil spring is loaded and unloaded to move a spool within a cylinder to variously expose and cover different shaped orifices to control hydraulic fluid flow. In the illustrated embodiment of the position selectable damper, three spool valves such as those illustrated in US 11,733,940 are used as the compression valves (21) and two such spool valves are used as the rebound valves (23). The structure of such spool valves is best illustrated in FIGS. 3, 8A and 8B. Optimally, each compression valve (21) and rebound valve (23) is a spool valve (22) with a pressure pin (24) adapted to block or permit hydraulic fluid flow when electronically closed or opened under the control of a solenoid valve (39). A solenoid valve (39) is illustrated in isolation in FIGS. 7A, 7C, 8A and 8B. As illustrated in FIGS. 2, 3 and 4, solenoid valves (39) are provided for active spool valves but not passive spool valves. Accordingly, there are two solenoid valves (39) for three compression valves (21) and one solenoid valve (39) for two rebound valves (23).

[0052] Control of the spool valves (22) by the solenoid valves (39) is illustrated in FIGS. 8A and 8B. When a solenoid valve (39) allows hydraulic fluid to flow into a low-pressure return tube (27), thus reducing the hydraulic pressure acting on the pressure pin (24) in a spool valve (22), the pressure pin (24) may travel outwardly within the spool valve (22) to reveal

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SUBSTITUTE SHEET (RULE 26) flow ports in the spool valve (22). This is an open (0) spool valve position as illustrated in FIG. 8A and by the solid arrow showing hydraulic fluid flow in the solenoid valve (39) in FIG. 7C. By contrast, when the solenoid valve (39) allows hydraulic fluid flow from a higher-pressure area within the spool valve (22) to increase the hydraulic pressure acting on the pressure pin (24), the pressure pin (24) may travel back inwardly within the spool valve (22) to again close the flow ports in the spool valve (22). This is a closed (C ) spool valve position as illustrated in FIG. 8B and by the broken arrow showing hydraulic fluid flow in the solenoid valve (39) in FIG. 7C.

[0053] The solenoid valves (39) are preferably 3-way high speed valves. The typical response times for such solenoid valves (39) to move to the open (0) and closed (C ) conditions is shown in the chart of FIG. 7B. The response times (RT) are shown in milliseconds (MS). The response times (RT) are shown for a continuous duty coil (CDC) in a 3-way normally closed (3WNC) configuration. In the cross-sectional image of FIG. 7C, hydraulic fluid flow through the solenoid valve (39) is shown by a solid arrow for an open (0) spool valve position, and by a broken-line arrow for a closed (C ) spool valve position, corresponding to the illustrations in FIGS. 8A and 8B discussed previously. For high level damper performance, each of the compression valves (21) and the rebound valves (23) may be closed within 3 milliseconds using a 3-way high speed solenoid valve.

[0054] A variety of possible valve configurations may be employed. For example, each of the compression valves (21) and the rebound valves (23) may be identical. Alternatively, any one of the compression valves (21) and rebound valves (23) may differ from another one of the compression valves (21) or rebound valves (23). In a preferred embodiment, one compression valve (21) remains passive during the rebound stroke and one rebound valve (23) remains passive during the compression stroke.

[0055] During the compression stroke, a hydraulic fluid passageway (25) conducts hydraulic fluid from the compression volume (13) through the compression valves (21) in the compression valve active mode to a low-pressure return tube (27) and through the rebound valves (23) in the rebound valve passive mode to the rebound volume (17). During the rebound stroke, the hydraulic fluid passageway (25) conducts hydraulic fluid from the rebound volume (17) through the rebound valves (23) in the rebound valve active mode to the low-pressure return tube (27) and through the compression valves (21) in the compression valve passive mode to the compression volume (13). The hydraulic fluid passageway (25) may comprise multiple segments. In addition, a hydraulic fluid reservoir (38) may be provided to accept excess hydraulic fluid when not required in the remainder of the damper (1), and conversely to

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SUBSTITUTE SHEET (RULE 26) supply additional hydraulic fluid to the remainder of the damper when required. A high- capacity, low-pressure side reservoir (38) assures insensitivity to temperature with minimal effect on vehicle spring rate at each wheel.

[0056] Although at least one low-pressure return tube (27) is required, in the illustrated embodiment two low-pressure return tubes (27) are employed to double the low- pressure return tube (27) volume. Increasing the number of low-pressure return tubes (27) helps to ensure that the pressure in these tubes remains sufficiently low for optimal damper performance. In addition, since hydraulic fluid in dampers is heated by being compressed and forced through orifices, the low-pressure return tubes (27) are provided with an array of external fins (37) to increase the surface area of the low-pressure return tubes (27) in contact with the ambient air to facilitate cooling of the hydraulic fluid. Again, such cooling improves damper performance.

[0057] An array of sensors (29) are spaced longitudinally on a sensor strip (30) which is placed longitudinally along an outer face of the damper body (3), as illustrated in FIG. 5. Typically, the sensors (29) are evenly spaced along the sensor strip (30) although any desired spacing is possible. The sensors are adapted to sense a location of the piston (11) as it moves longitudinally inside the damper body (3). Although different means to sense the location of the piston (11) are available, a magnet (33) located on or within the piston (11) provides a useful object to be sensed by the sensors (29). Multiple magnets (33) may be employed as required. The more sensors which are employed, the greater is the sensitivity or precision of locating the piston (11). It may, however, be beneficial to maintain sufficient spacing of the sensors for optimal function. Hall-effect sensors are particularly useful in this regard.

[0058] A controller (31), which may comprise multiple parts, receives signals from the sensors (29). In response to these signals, the controller is adapted to progressively close selected valves in the arrays of compression valves (21) and rebound valves (23) to increase the resistance to hydraulic fluid flow dependent upon the sensed piston (11) location during the compression stroke and the rebound stroke respectively. The controller (31) is preferably programmed to select the piston (11) positions where a selective closure of any one of the compression valves (21) or rebound valves (23) occurs to vary pressure response zones. In a further refinement, the pressure response zones are varied to adapt to conditions of a vehicle and of driving surfaces. The pressure response zones may be varied remotely by means of a vehicle-mounted human interface module (40), such as a dedicated tablet device, wirelessly using a mobile computer software application loaded on a hand-held smartphone (41), or by

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SUBSTITUTE SHEET (RULE 26) other suitable means, as shown in FIG. 6. The controller (31) may comprise a circuit board connected to the sensor strip (30), as illustrated in FIG. 5.

[0059] A display for remote setting of the pressure response zones is illustrated in FIG. 6. The display may appear on the hand-held smartphone (41) or on a vehicle-mounted human interface module (40), such as a dashboard-mounted tablet, either of which may communicate with the controller (31). A set zero-line (0) is shown midway along the damper body (3). A compression stroke (CS) zone is shown running in either direction essentially the length of the damper body (3) while a rebound stroke (RS) zone is shown also running in either direction essentially the length of the damper body (3). The notations 30, 50, and 80 indicate the percentage of stroke boundary positions for the selected pressure response zones in the compression stroke (CS) zone. The notations -30, -60, and -80 indicate the percentage of stroke boundary positions for the selected pressure response zones in the rebound stroke (RS) zone. Compression zone adjustment is indicated by the notation CZA while rebound zone adjustment is indicated by the notation RZA. BR indicates a soft range in the compression zone, BM indicates a mid-range in the compression zone, and BS indicates a stiff or firm range in the compression zone. RN indicates a normal range in the rebound zone while RS indicates a stiff or firm range in the rebound zone. Each of these ranges is fully adjustable, unlike with prior art dampers. Even the set- zero (0) line may be shifted. Each of the vehicular dampers (1) located at four wheels of the vehicle may be controlled separately, or all vehicular dampers (1) may be set with the same pressure response zone parameters.

[0060] The enhanced performance of the disclosed position selectable dampers over that of a conventional, prior art position sensitive damper (such as that illustrated in FIGS. 1 A to IE) may be illustrated graphically. FIGS. 1A to ID illustrate a position sensitive damper with only one step in force level for compression and rebound strokes. With additional ports and piping as shown in FIG IE, the prior art position sensitive damper may have three steps in either direction. When force (F) and displacement (D) at the piston of a conventional position selective damper are measured on a testing apparatus and plotted on a screen, a so-called “football curve,” as illustrated in FIG. 9A, is generated. The football curve is an irregularly shaped closed loop which shows sharp pressure increases and decreases as the orifices which permit hydraulic fluid flow are blocked and reopened, respectively. The shape of the football curve is fixed given that the structural parameters of the conventional damper are fixed when it is manufactured, as previously discussed.

[0061] By contrast, the parameters of the position selectable damper may be varied as desired. The positions where the force step occurs are electronically adjustable in an

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SUBSTITUTE SHEET (RULE 26) essentially infinite manner. Each step position may be individually adjusted, and a very large number of steps is possible. Thus, multiple force-velocity curves may be generated. The position selectable damper force- velocity multiple football curves are illustrated in FIG. 9B. A solid line closed loop curve represents a baseline parameter setting. The dashed line closed loop curve offset from the solid line represents a different parameter setting. Although only a single dashed line is shown, multiple such different parameter settings are possible. With the position selectable damper illustrated below the corresponding football curves, it is possible to step between three compression force levels and two rebound levels. It is possible to jump back and forth between a high rebound force level and a low rebound force level as frequently as desired. In practice, it is preferable to generate football curves as shown in FIG. 9B. It is also possible to omit a force transition by not switching between different force levels, if desired. In the position selectable damper, a range of force-velocity curves with customizable transition positions is created by actively controlling the compression valves (21) and the rebound valves (23), particularly with such valves being spool valves (22). A range of different configurations for various terrains, ambient conditions, vehicle mass, vehicle setup, or user preferences can be defined. As previously discussed, when the damper system is so configured, the user may adjust pressure zone transition points from within the vehicle using a vehicle mounted human interface module (40), such as a dedicated tablet device, or remotely using, for example, a mobile software application loaded on a hand-held smartphone (41).

[0062] Although the different examples are illustrated as having specific components, the examples of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the embodiments in combination with features or components from any of the other embodiments.

[0063] The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.

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SUBSTITUTE SHEET (RULE 26)

Claims

1. A vehicular damper comprising: a cylindrical damper body; a piston rod connected at a first end external to the damper body to an unsprung mass or a sprung mass of a vehicle; the piston rod connected at a second end internal to the damper body to a piston, the piston adapted to reciprocate within the damper body during compression strokes and rebound strokes; a variable hydraulic fluid compression volume within the damper body limited by a position of a compression face of the piston; a variable hydraulic fluid rebound volume within the damper body limited by a position of a rebound face of the piston; an array of compression valves connected in parallel adapted to provide resistance to a passage of hydraulic fluid during the compression stroke in a compression valve active mode and to provide minimal resistance to the passage of hydraulic fluid during the rebound stroke in a compression valve passive mode; an array of rebound valves connected in parallel adapted to provide resistance to the passage of hydraulic fluid during the rebound stroke in a rebound valve active mode and to provide minimal resistance to the passage of hydraulic fluid during the compression stroke in a rebound valve passive mode; a hydraulic fluid passageway which conducts hydraulic fluid from the compression volume through the compression valves in the compression valve active mode to a low pressure return tube and through the rebound valves in the rebound valve passive mode to the rebound volume during the compression stroke, and from the rebound volume through the rebound valves in the rebound valve active mode to the low pressure return tube and through the compression valves in the compression valve passive mode to the compression volume during the rebound stroke; an array of sensors spaced longitudinally along an outer face of the damper body adapted to sense a location of the piston; and a controller adapted to progressively open and close selected valves in the arrays of compression valves and rebound valves to increase or decrease the resistance to hydraulic fluid

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SUBSTITUTE SHEET (RULE 26) flow dependent upon the sensed piston location during the compression stroke and the rebound stroke respectively.

2. The vehicular damper of claim 1, wherein the sensors are Hall-effect sensors adapted to sense a piston-mounted magnet.

3. The vehicular damper of claim 1 , wherein the arrays of compression valves and rebound valves comprise spool valves.

4. The vehicular damper of claim 3, wherein the array of compression valves comprises three spool valves.

5. The vehicular damper of claim 3, wherein the array of rebound valves comprises two spool valves.

6. The vehicular damper of claim 1 , wherein an exterior of the low pressure return tube is provided with an array of fins to air cool the hydraulic fluid.

7. The vehicular damper of claim 1, wherein each of the compression valves and rebound valves is adapted to close electronically under the control of a solenoid valve.

8. The vehicular damper of claim 7, wherein each of the compression valves and rebound valves may be closed within 3 milliseconds.

9. The vehicular damper of either one of claims 7 and 8, wherein each compression valve and rebound valve is a spool valve with a pressure pin adapted to block hydraulic fluid flow when electronically closed.

10. The vehicular damper of claim 1, wherein the controller is programmed to select the piston positions where a selective closure of any one of the compression valves and rebound valves occurs to vary pressure response zones.

11. The vehicular damper of claim 10, wherein the pressure response zones may be varied to adapt to conditions of a vehicle and of driving surfaces.

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SUBSTITUTE SHEET (RULE 26)

12. The vehicular damper of claim 11 , wherein the pressure response zones may be varied remotely by means of one of a vehicle mounted human interface module and a mobile computer software application loaded on a hand-held smartphone.

13. The vehicular damper of claim 1, wherein each of the compression valves and rebound valves is identical.

14. The vehicular damper of claim 1, wherein any one of the compression valves and rebound valves may differ from another one of the compression valves and rebound valves.

15. The vehicular damper of claim 1, wherein one compression valve remains passive during the rebound stroke and one rebound valve remains passive during the compression stroke.

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SUBSTITUTE SHEET (RULE 26)