Adjustable and progressive coil spring system for two wheeled vehicles

An adjustable coil spring system placed within a leg of a vehicle such as a mountain bicycle fork. The spring system comprises an adjustable first soft spring seated on top of a second firm spring having greater length than the first soft spring. A coupler assembly is positioned between two springs comprised of a threaded bolt threadedly received within a coupler. A spring adjustment mechanism may comprise a knob connected to the threaded bolt through a non-round shaped shaft, wherein the threaded bolt is disposed within the first soft spring. As the knob rotates, the coupler is moved up along the threaded bolt, decreasing the length of the first soft spring, thereby increasing firm spring characteristics of the spring system. As the knob rotates in an opposite direction, the coupler moves down, increasing the length of the first soft spring, thereby increasing soft spring characteristics of the spring system.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of spring characteristics in vehicle suspension systems such as those used in bicycle and motorcycle suspension systems that are designed to improve compressibility of a spring system in response to riding conditions and the rider's weight.

2. Description of the Prior Art

Spring and shock distribution systems for changing the spring characteristics of a mountain bicycle fork depending on the riding conditions or the rider's weight are generally known. In the prior art, one way to change the spring characteristics is to change the entire spring assembly to a different spring assembly. In general, the rider wants a suspension spring to be soft in normal travel but if the rider hits bumps, it needs to be stiffer so the rider has a bottom out protection. In the prior art, another variation is to have one spring with two characteristics. Also, another variation is to have one spring inside the other where the softer spring is on the outside and the stiffer spring is on the inside. The problem with the prior art is that it's a static system. Once the rider selects the spring characteristics, the rider cannot adjust the spring compression characteristics or spring pre-load while riding.

The following 14 patents and published patent applications are the closest prior art references which are known to the inventors.

11. U.S. Pat. No. 6,471,197 issued to Peter Denk et al. and assigned to Denk Engineering GmbH on Oct. 29, 2002 for “Spring Device For Shock Absorber With Adjuster” (hereafter the “Denk Patent”);

14. International Publication Number WO 2005/054046 issued to Brian Jordan et al. and assigned to SRAM Corporation on Jun. 16, 2005 for “Adjustable Gas Spring Suspension System” (hereafter the “Jordan International Publication”).

With respect to the Jerz Patent, this deals with a vehicle suspension system where there is a combination of a hard spring and a soft spring, and the travel of the soft spring is set by various stops and limit stops at certain locations near the bottom and near the top of the spring. Specifically the concept is “a vehicle suspension system including two springs connected in series, with one of the springs being stiffer than the other, and with the springs being so related that under normal load conditions the softer of the two springs is effected to provide a very gently cushioned ride, while upon the imposition of heavier load forces, the vehicle is supported more stiffly and primarily by the stronger spring. The conversion between these two conditions may be effected automatically, by engagement under heavy load conditions of stop shoulders acting to limit compression of the light spring. Similarly, upon excessive extension of the springs, an additional set of stop shoulder may automatically become effective to limit the amount of extension of the softer spring and cause the stiffer spring to resist further extension. A shock absorber may be utilized in conjunction with the springs, and may itself carry or include one or more of the stop shoulders”.

The Okazima Patent deals with a vehicle suspension system for a fork assembly. Specifically the concept is to adjust the amount of spring force with a knob (36), where the appropriate selection of the position of the stopper (47) or of the cam seat (33) caused by rotating knob (36) to rotate the cam seat thereby changing the relative position of the legs (34) with respect to the cam surfaces (29) of the cap (27) and the second helical spring (45) may be preloaded or the preload of the second helical spring (45) may be appropriately varied.

The Nishikawa Patent discloses the ability to adjust the tension of the shock absorber by utilizing a dial (11) or dial (111) as shown inFIG. 6. The shock absorber itself is comprised of a piston cylinder assembly. A coiled suspension spring (16) is arranged between an annular upper spring seat (14) supported on the upper mounting member (11) and a lower spring seat (15) vertically adjustably mounted on the external periphery of the tubular casing (2) by appropriate well known means. The upper surface of the spring seat (14) is provided on the top surface with a scale (23) to indicate the intensity of the damping force. The upper spring seat (14) thus serves as a damping force adjusting dial rotatable relative to the upper mounting member (11).

The Cowan Patent is a design patent which protects the shape of the object.

The Ueno Design Patent that protects the shape or ornamental beauty of a shock absorber for a motorcycle but does not disclose how the device functions.

The Behrens Patent is a design patent for a bicycle fork.

The Johnsen Patent discloses a dual sping damping system having an inner spring and an outer spring where the adjustment is made to the outer spring by the rotatable ball valve lever (22).

The '075 Turner Patent for a “Bicycle Fork Suspension With Exchangeable Spring Unit” relates to various damping systems that can be included in the bicycle fork, including a hydraulic system and the concept of adjusting a preload to a knob.

The '998 Turner Patent deals with adjustable springs which can be air springs or gas springs as well as coil and elastomer springs. This patent deals discloses a compressor piston and other additions in order to improve suspension response.

The Rathburn Patent discloses a suspension fork including an operating device mounted externally to the telescoping fork leg that permits the rider to selectively shorten or lengthen the extent of relative travel between the inner and outer tubular sections of the fork.

The Denk Patent discloses the concept of having a single spring on top which can be adjusted for spring distance length by a rotatable knob. Specifically, the patent in relevant part reads as follows “the fixed shock absorber (10) which is, for example, configured as a cartridge in a bicycle fork or as an independent shock absorber, comprises a shock absorber cover (12) having a thread about its periphery into which spring (14) engages, whereby the shock absorber (10), respectively absorber cover (12), is movably fixed relative to spring (14). Shock absorber (10) is a preferably fixed at a position relative to an embracing member. The end (16) of the spring (14) is fixed in a rotocap (18). The rotocap (18) is mounted rotatably about axis (20). Upon rotating cap (18), spring (14) turns so that the thread pitch of spring (14) displaces axially relative to the thread. For example when shock absorber cover (12) including thread is displaced upwardly as a consequence of a rotation of rotocap (18) by the spring (14) about the distance (22), the effective spring length, which corresponds to the spacing between rotocap (18) and absorber head (12), decreases from the dimension (24) to the dimension (26).”

The Becker Patent discloses the concept of an adjustment mechanism on top a bicycle which is a preload adjuster assembly with a single spring on which the load is may be adjusted. The preload adjuster assembly (330) is desirably provided to allow adjustment of the preload on the second spring (322). The preload adjuster assembly (330) generally comprises an adjuster cap (332), an adjuster shaft (334) or barrel (336) and an adjuster knob (338). Rotation of the adjuster knob provides a plurality of preload adjustments.

The London Patent deals with adjustable hydraulic damper units that disclose the ability to adjust the effectiveness of spring damping via an adjustment knob.

The Jordan Patent discloses an Adjustable Gas Spring Suspension System”.

There is a significant need for an improved shock distribution system that may be adjusted while the vehicle is in operation. Further there is a need for suspension system that has soft and firm setting adjustable spring characteristics.

SUMMARY OF THE INVENTION

The present invention is an adjustable coil spring system placed within a leg of a vehicle such as a mountain bicycle fork. The spring system comprises a first soft spring with an adjustable compressible distance, which is seated on top of a second firm spring having greater compression capability than the first soft spring. A coupler assembly comprising a threaded bolt threadedly received within a coupler is positioned between the two springs. A spring system adjustment means may comprise a knob connected to a non-round shaped shaft sliding within the threaded bolt having a non-round shaped central opening which is disposed within the first soft spring. As the knob is rotated in a given direction, the threaded bolt rotates correspondingly. The coupler then moves up along the threaded bolt and decreases the compression range of the first soft spring, thereby increasing spring system compressing force.

It has been discovered, according to a first preferred embodiment of the present invention, that if a spring system contained in a bicycle fork leg comprises a first soft spring mounted on top of a second firmer spring, then if the first soft spring is engaged with an adjustment means located at a readily accessibly position on a bicycle fork leg, then the spring compression characteristics of the system can be readily modified by the adjustment means causing the travel length of the first soft spring to be increased or deceased.

It has further been discovered, according to the first preferred embodiment of the present invention, that if the first soft spring is positioned on a coupler of the coupler assembly which has an adjustment receiving means and the second firm spring is positioned below the coupler, the adjustment means can cause the compressible distance of the first soft spring to be largely varied to thereby adjust the spring force of the spring assembly while the spring force of the second firm spring remains the same.

It has been additionally discovered, according to the second preferred embodiment of the present invention, that if a spring system contained in a bicycle fork leg comprises a first soft spring mounted on the bottom of a second firmer spring, then if the first soft spring is engaged with an adjustment means located at a readily accessibly position on a bicycle fork leg, then the spring compression characteristics of the system can be readily modified by the adjustment means causing the travel distance of the first soft spring to be increased or deceased.

It has further been discovered, according to the second preferred embodiment of the present invention, that if the second firm spring is positioned on a coupler of the coupler assembly which has an adjustment receiving means and the first soft spring is positioned below the coupler, the adjustment means can cause the compressible distance of the first soft spring to be largely varied to thereby adjust the spring force of the spring assembly while the spring force of the second firm spring remains the same.

It has further been discovered, according to the first and second preferred embodiments of the present invention, that by selecting a suitable thread size for a screw assembly configured to adjust the compression of the soft spring in a spring system, a user may quickly and dynamically adjust the spring force for user preferred characteristics while the vehicle is still in motion.

It has also been discovered, according to a third preferred embodiment of the present invention, that if a spring system contained in a bicycle fork leg is the opposite of the first preferred embodiment of the present invention and comprises a first soft spring mounted on the bottom of a second firmer spring, then if the first soft spring is engaged with an adjustment means located at a readily accessibly position on a bottom end of a bicycle fork leg, then the spring compression characteristics of the system can be readily modified by the adjustment means causing the travel distance of the first soft spring to be increased or deceased.

It is therefore an object of the present invention to provide a rapidly adjustable spring system for a vehicle such as a mountain bicycle by providing a spring system contained in a bicycle fork leg which comprises a first soft spring combined with a second firm spring in series. The first soft spring is engaged with an adjustment means located at a readily accessibly position on a bicycle fork leg so that the spring compression characteristics of the system can be readily modified by the adjustment means causing the travel distance of the first soft spring to be increased or deceased.

It is also an object of the present invention to provide a spring system containing a first shorter soft spring in conjunction of a second longer firm spring and an adjustable means for absorbing shock in order to dynamically improve handling performance in vehicles according to the user's preferences.

It is a further object of the present invention to provide a spring system containing a first shorter soft spring in conjunction of a second longer firm spring and an adjustable means that enables a user to dynamically adjust the spring characteristics in the field while the vehicle, such as a bicycle, is still in motion.

It is an additional object of the present invention to provide a spring system containing a first shorter soft spring in conjunction of a second longer firm spring and an adjustable means for absorbing shock that does not require additional cabling or other external means to a peripheral device attached elsewhere on the vehicle for manipulating the spring system compression characteristics.

It is another object of the present invention to provide a spring system containing a first shorter soft spring in conjunction of a second longer firm spring and an adjustable means for absorbing shock that does not add a significant amount of weight to the system.

It is a still further object of the present invention to provide two springs in series in conjunction with a coupler assembly, which can generate multiple preferred embodiments of the present invention on different mechanical structures, and that has a minimum amount of working parts. Similarly it is an object to provide a system that requires no cabling.

It is still a further object of the present invention to provide a spring system containing a first shorter soft spring in conjunction of a second longer firm spring and an adjustable means for absorbing shock that provides a one coil spring system which satisfies many different riders having varying weights and ride stiffness preferences.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIG. 1which is a front elevational view in partial cross-section, there is illustrated a vehicle fork100containing the present invention adjustable and progressive coil spring system50within a first fork leg200. The first fork leg200is constructed with a set of two matched telescoping hollow rods combined together, a first inner telescoping hollow rod202and a second outer telescoping hollow rod204. Similarly, a second fork leg201is comprised of a second inner telescoping hollow rod203and an outer telescoping hollow rod205. A transverse front wheel axle206is affixed to an outer end of the respective first and second outer telescoping hollow rods204and205, and a crown300is transversely connected to an outer end of the respective first and second inner telescoping hollow rod202and204. It will be appreciated that the inner and outer telescoping hollow rods are movable relative to each other along their longitudinal directions.

As further illustrated inFIG. 1, the adjustable and progressive coil spring system50for vehicles is comprised of a first spring10having a first end13and a second end15, a second spring20having a first end21and a second end23, a coupler assembly30which is retained between the first soft spring10and second firm spring20, and a compression rod system110having a fixed length, wherein the first and second spring, the coupler assembly, and the compression rod system are placed within the first inner and outer telescoping hollow rods202and204. A spring adjustment knob with detent40is placed at the outer end of the inner telescoping hollow rod202. It will be appreciated that the first spring10is selected such that the first spring is comparatively tender or softer than the second spring20, and noticeably shorter than the second spring. The relative mechanical positions are illustrated inFIG. 1for the first soft spring10, the second firm spring20, the coupler assembly30, the compression rod system110, and the spring adjustment knob40, wherein the first soft spring10is placed above the second firm spring20, and the second spring20at the second end23is placed on the top of compression rod system110.

The coupler assembly30of the present invention is illustrated inFIG. 2, which is comprised of a male threaded bolt31and a female threaded coupler32. The threaded bolt31is threadedly received within the coupler32. The male threaded bolt31is comprised of a first disc end3and a second disc end9having an inner round bore extending through both ends, wherein a non-round shaped central opening2is located on the first end3. In the preferred embodiment, the non-round central opening2is hexagonal. The coupler32is generally a “D” shaped nut with female threads having a transverse first top end5and a transverse second bottom end7, and an outer flat vertical wall1, which is aligned with an outer cylindrical wall11. As illustrated, the coupler32at a middle position is surrounded by a transverse ring22having a first surface4and second surface6, which evenly divides the flat and cylindrical wall1and11.

In a first preferred embodiment of the present invention as illustrated inFIG. 3, the first soft spring10is positioned so that its second end15sits on top of the first surface4of the coupler32of the assembly30. The first end3of the threaded bolt31is disposed within the first soft spring10, and the first end5of the coupler32is surrounded by the second end15of the first soft spring10. It will be appreciated that the second end15of the first soft spring10is also a“D” shaped, which matches the shape of the first end5of the coupler32. The second surface6of the coupler32sits on top of the second firm spring20. The second end7of the coupler32and the second end9of the threaded bolt31are disposed within the second firm spring20, wherein the firm spring20has the “D” shaped first end21to match the same “D” shape of the second end7of the coupler32. As further illustrated inFIG. 3, a non-round shaped shaft8with a length at least equal to the height “H” of the first soft spring10is comprised of a top portion12and a bottom portion14where the bottom portion14of the non-round shaped shaft8is slid into the non-round shaped center opening2of the threaded bolt31. In this way the first soft spring10surrounds the non-round shaped shaft8. Alternatively described, the non-round shaped shaft8is positioned within the first soft spring10. In this preferred embodiment, the non-round shaped shaft8is also hexagonal to match the shape of the center hole2of the threaded bolt31. However, any non round shapes for the shaft8and opening2are within the spirit and scope of the present invention including but not limited to a triangular, square, pentagonal, hexagonal and oval shape. A tension adjustment knob with detent40connected to a rod having a lower retaining portion16is used to turn the non-round shaped shaft8for varying the length “H” of the first soft spring10. Referring toFIGS. 3 and 4, there are illustrated the spring adjustment knob with detent40, a top fastening portion18for mounting the knob onto the outer end of the inner telescoping rod202, and a lower retaining portion16for fixedly retaining the top portion12of the non-round shaped shaft8.

Referring once again toFIG. 1, there is illustrated that the present invention adjustable and progressive coil spring system1inside of the fork leg200in a no-rider load situation, when the first soft spring10and the second firm spring20are at their almost non compressive conditions since they are only under compression from a very limited load such as the weight of a bicycle. In contrast to the non-loaded condition, it will be appreciated that the first soft spring10and the second firm spring20will be relatively compressed when a rider is riding the bicycle. Under this situation, the rider can apply a changeable spring compression function of the adjustable and progressive coil spring system1of the present invention for the rider's needs with respect to a road-riding condition.

The rider can reduce almost all compressible distance of the first spring10if the rider wishes to have firm spring compression characteristics while riding the bicycle, which is illustrated in the elevational view ofFIG. 4. In this condition, the first spring10is substantially compressed throughout the spring length adjustment by rotation of the knob40. The knob40has been rotated counter clockwise by several turns so that the non-round shaped shaft8is slid into the threaded bolt31of the coupler assembly30and has driven the threaded bolt31with the same number of turns while the coupler32remains unturned due to its rotational restriction from respective connections of the“D” shaped second and first ends15and21of the first and second spring10and20and the “D” shaped first and second ends5and7of the coupler32. It will be appreciated that, the coupler32is driven to move upward along the turned threaded bolt31while the turned threaded bolt31maintains its vertical position unchanged as the threaded bolt31is rotated. The first end5of the coupler32which supports the second end15of the soft spring10moves close to the first end3of the threaded bolt31until the first end5of the coupler32contacts the first end3of the threaded bolt31. During this process, the turning force applied to the knob40by the rider is changed to a compression force continually applied to the first soft spring10to reduce the spring length, which makes the first soft spring10gradually compressed and finally make it substantially compressed as illustrated inFIG. 4. In this situation, the spring system50comprising of the softer first spring10in conjunction with the second firm spring20predominantly outputs a firm spring compression characteristics of the second spring20, which will be suitable for a stiff riding condition.

In an opposite situation, the rider can rotate the knob40in a clockwise direction to expand the length of the soft spring10if the rider wants soft spring compression characteristics, as illustrated inFIG. 3which shows the soft spring10is almost fully expanded. To achieve this condition, the rider turns the knob40to drive the non-round shaped shaft8which further drives the threaded bolt31in the same clockwise direction, to thereby move the coupler32down to thereby increase the distance between the first surface4of the coupler32and the position of the first end13of the first spring10to expand the length of the soft first spring10. Concurrently the downward coupler32compresses the firm second spring20, which results in that the compressible distance of the firm spring20being slightly reduced since the second firm spring20is longer than the first soft spring10. Therefore, the first soft spring10can be maximumly expanded when the coupler31at its second end7moves down to contact the second end9of the threaded bolt31. At this point, the spring system1maximumly exhibits the soft spring compression characteristics.

It will be appreciated that the above disclosure including the second hard or firm spring20is selected in order to improve the fork spring compression characteristics and specifically to optimize the performance of the shock absorbing system in response to riding conditions and the user's weight. The middle ring22of the coupler32of the assembly30is circular in order to facilitate retention within the fork leg200. The non round “D” shaped first and second end5and7of the coupler also accommodates the respective seconded15of the first spring10and the first end21of the second spring20so that the coupler32itself cannot be turned when the threaded bolt31is turned. The length of the non-round shaped shaft8is selected to be of a length at least equal to the length of the first spring10. The bolt31is threaded along its length in order to accept the coupler32, wherein the non-round shaped hole2in the center of the coupler assembly30is further fixedly retained by the lower retaining portion14of the shaft8through the upper remaining portion12connected to the adjustment knob with detent40. The coupler32may quickly be moved up and down by the non-round shaped shaft8in response to adjustments made to the knob40. The first head3of the threaded bolt31is affixed to and turned by the non-round shaped shaft8. A portion of the first soft spring10and second firm spring20surround the threaded bolt31.

The exact position of the ring22of the coupler31of the assembly30as it is engaged on the non-round shaped shaft8changes the combination of spring compression characteristics. For example, referring toFIG. 3, there is illustrated an elevational view with the first softer spring10almost fully extended. In this position the spring system of the softer first spring10in conjunction with the second firm spring20outputs soft spring compression characteristics.

It will be appreciated that, between the positions of the coupler32illustrated inFIGS. 3 and 4, the spring system50comprising the first soft spring10in conjunction with the second firm spring20outputs intermediate spring compression characteristics. Therefore,FIGS. 1,3, and4illustrate how the present invention can change the spring compression characteristics from soft to firm, or to various in-between spring compression characteristics by the spring system containing the first soft spring10and second firm spring20in conjunction with the coupler assembly30having the threaded bolt31threadedly received within the coupler32.

The user may choose the soft spring compression characteristics for the spring system for his needs by turning the knob with detent40clockwise, such that the coupler32moves down to expend the soft spring10.

The knob40itself may be configured with quick click settings that act to partially or wholly engage and compress the first soft spring10. To modify the stiffness of the spring system, the first soft spring10is compressed against the knob40and top cap24by different amounts of compression. The user may reduce the first soft spring10tension in order to provide softer spring compression characteristics by turning the spring adjustment knob with detent40clockwise such that the coupler assembly30allows the first spring10to assume its natural extended position. Alternatively the rider may desire a stiffer ride in response to riding conditions. In this instance the rider may turn the adjustment knob40in the opposite direction and compress the first soft spring10. As the user turns the spring adjustment knob40counter-clockwise, the coupler32travels up the threaded bolt31allowing the first spring10to compress. For rough terrain conditions, a partial to complete compression of the first soft spring10is desirable in order to absorb and better distribute the larger impact forces the user may encounter.

The relative travel distances “D1” between a soft setting and a firm setting for the soft spring10is illustrated inFIG. 3, where the soft spring10has a length “H” when it is fully relaxed.

Referring toFIGS. 3 and 4, there is also illustrated a side cross-sectional view of the adjustable knob with detent. The knob40comprises a spring26and detent locking mechanism28. When the user turns the knob40, there may be as many as five settings the user may quickly choose from. As the knob turns the detent locking mechanism28which is forced downwardly by the spring26, the detent28is forced out of a pocket (not shown) in plate35until it engages in the next pocket. The engaging mechanism enables a user to readily tell by feel how many the compression settings have been adjusted before impact over a different terrain takes place.

Referring toFIG. 5, there is illustrated a top perspective view of the bicycle fork100with the compression adjustment knob40. Also visible is a steering column120, a first fork leg200which comprises the present invention, a second fork leg201, the crown300, and a top portion of a front wheel150. For comparison purposes, a standard fork suspension cap160is also shown. One key aspect of the present invention is the relative size of the adjustment knob40in that the overall size is comparable to the standard fork cap160, thereby reducing the added weight of the spring compression system1while still ensuring quick access for changing the spring compression characteristics of the first soft spring10at any time, even while the bicycle is in motion. Since the adjustment knob40is at the top of the fork100, it can be easily and quickly reached by a rider to enable the rider to make rapid adjustments to the compression characteristics of the spring system to adjust for changing conditions during the ride.

Referring toFIG. 6, a fork travel to spring force graph is shown that relates the distance of movement of the bicycle fork100with respect to the applied force of the spring compression system1set in its softest setting510and its firmest setting520. When a force of roughly less than forty pounds of force is applied, both settings510and520respond similarly with respect to overall fork travel. However, as the applied force increases, the softer setting line510diverges from the firm setting line520. It can be seen from the graph that the soft setting line510has greater fork travel than the firm setting line520when an equal force is applied. At maximum fork travel of 140 mm, a further innovation of the spring compression system1is shown as the difference of applied force in order to incur maximum fork travel between the soft setting line510and firm setting520is seventy-five pounds of bottom-out load. Again this difference in firmness of the system may be accomplished in as little as five turns of the adjustment knob40.

Through application of the present invention adjustable and progressive coil spring system50, the vehicle fork100can be designed in various ways but holds the same spring compression characteristics.

Referring toFIG. 7, there is illustrated second preferred embodiment of the vehicle fork100′ containing the present invention adjustable and progressive coil spring system50′ placed inside of a first fork leg200′. In contrast to the configuration where the first soft spring10sits on the top of the firm second spring20as in the first preferred embodiment shown inFIG. 1, in this second embodiment the second firm spring20can be arranged to sit on the top of the first soft spring10in conjunction of the coupler assembly30. As illustrated, the first fork leg200′ is comprised of the inner telescoping hollow rod202movably received within the outer telescoping hollow rod204, when the first fork leg200′ at the outer end of the inner telescoping hollow rod202is transversely connected to the crown300, and at the outer end of the outer telescoping hollow rod204transversely connected to the wheel axle206. Within the hollow telescoping rods, there are installed with the first soft spring10and the second firm spring20, the coupler assembly30, and the compression rod system110, wherein the second firm spring20at its first end21is placed under the spring adjustment knob with detent40which is placed at the outer end of the inner telescoping rod202, and at its second end23is placed on the first surface of the middle transverse ring22of the coupler32, wherein the threaded bolt31is threadedly received within the coupler32. The middle ring22of the coupler sits on the first end13of the first soft spring10, and the second end15of the first soft spring10is placed on the top of the compression rod system110. In accordance with the second preferred embodiment, the non-round shaft8is at least longer than the length of the second firm spring20. From application of the spring system50′, the soft spring compression characteristics can be achieved with a counter clockwise rotation of the spring adjustment knob with detent40, which moves the coupler32up to compress the firm second spring20, and relax the soft first spring10. In reverse, if the firm spring compression characteristics is desired, the spring adjustment knob with detent40can be rotated clockwise to move the coupler32down, which compresses the first soft spring10and simultaneously slightly relaxes the second firm spring20as shown inFIG. 7.

For the third preferred embodiment of the vehicle fork100″ shown inFIG. 8, there is illustrated first fork leg200″, which is the same as the first fork leg200in the first preferred embodiment introduced inFIG. 1but is reversely installed into the fork100″, wherein the outer end of the outer hollow telescoping rod204is transversely connected to the crown300, and the outer end of the inner hollow telescoping rod202is transversely connected to the wheel axle206. In this setting, the spring adjustment knob with detent40is placed at the bottom of the first fork leg200″ and adjacent to the wheel axle206, which makes adjustment of the spring system unavailable for the rider while riding the vehicle such as the bike. This it is the only difference in the third preferred embodiment of the vehicle fork, in comparison with the first preferred embodiment.

Therefore, the key novel feature of the present invention is to have a combination of a first soft spring10effectively seated on top of a second hard or firm spring20through a connection of a coupler assembly30comprising a threaded bolt31threadedly received within a coupler32where the compression characteristics of the overall spring assembly are modified by adjusting the length of the first soft spring10relative to the length of the second hard or firm spring20, which almost remains the same. By enabling the compression characteristics of the first soft spring10which sits on top of the second hard or firm spring20to be modified by the adjustment mechanism which is easily reachable by a rider while the rider is riding on the vehicle such as a bicycle, the rider can adjust the overall spring compression of the fork mechanism while the rider is riding on the bicycle so that adjustments can be rapidly made to the changing conditions along the path that is being ridden.

The present invention spring compression system1can be used with any vehicle fork such as a bicycle fork or a motorcycle fork.

Defined in detail as a first embodiment, the present invention is a coil spring system to be used within a leg of a bicycle fork comprising: (a) a first soft spring with a first and second end having a given height when in the fully extended condition, and a second firm spring with a first and second end having a greater height than the first soft spring; (b) a coupler assembly comprising a coupler and a threaded bolt, the coupler having a first and second end including an internally threaded bore and a transverse outer ring located at the middle of the coupler, the transverse ring having a first surface and a second surface wherein the first soft spring at its second end rests on the first surface and the second firm springs at its first end rests below the second surface, the first soft spring positioned above the second firm spring so that a the first end of the first soft spring rests adjacent a top end of the vehicle fork leg, the threaded bolt having a first and second end including a central bore with a non-round opening at the first end, the threaded bolt being threadedly received at the center of the coupler; (c) a non-round shaped shaft having a length at least equal to the height of the first soft spring, the non-round shaped shaft having a top portion and a bottom portion, the bottom portion of the shaft inserted within the central bore with the non-round opening of the coupler member such that the threaded bolt is centrally positioned within the first soft spring; (d) an adjustment knob having a knob, a top fastening portion for mounting the knob onto a top of the leg of the bicycle fork and a lower retaining portion for fixedly retaining the top portion of the non-round shaped shaft; (e) a compression rod system including the second firm spring retained at the top of the compression rod system, the first soft spring and the second firm spring and the coupler member and the non-round shaped shaft and the compression rod system resting within the leg of the bicycle fork; and (f) the spring compression range of the first soft spring is selectively increased by turning the knob in one direction to cause rotation of the threaded bolt which further moves the coupler away from the knob to thereby increase the height of the first soft spring and the spring compression range of the first soft spring is selectively decreased by rotating the knob in the opposite direction to cause the coupler to move closer to the knob to thereby decrease the height of the first soft spring.

For the first embodiment, defined more broadly, the present invention is a coil spring system to be used within a leg of a bicycle fork, comprising: (a) a first soft spring having a given length when in the fully extended condition and having a first end and a second end, and a second firm spring having greater length than the first soft spring and having a first and second end, the first soft spring positioned on top of the second firm spring so that the second end of the first soft spring rests adjacent the first end of the second firm spring and the first end of the first soft spring rests adjacent a top end of the bicycle fork leg, both springs resting within the leg of the bicycle fork; (b) a coupler assembly comprising a threaded bolt threadedly received with a coupler, the coupler positioned between the first and second spring; and (c) a spring adjustment means retained on the bicycle fork at a location adjacent the top of the fork leg and in communication with the first soft spring through the coupler so that the length of the first soft spring is selectively increased by moving the spring adjustment means in one direction and the length of the first soft spring is selectively decreased by moving the spring adjustment means in the opposite direction.

For the first embodiment, defined most broadly, the present invention a coil spring damping system to be used within a leg of a vehicle fork, comprising: (a) a first soft spring with a first and second end having a given length when in the fully extended condition, and a second firm spring with a first and second end having a greater spring length than the first soft spring, the first soft spring positioned on top of the second firm spring so that the second end of the first soft spring rests adjacent a first end of the second firm spring and the first end of the first soft spring rests adjacent a top end of the vehicle fork leg, both springs resting within the leg of the vehicle fork; (b) a coupler means is placed between the first and second springs; and (c) a spring adjustment means retained on the vehicle fork leg at a location adjacent the top of the fork leg and in communication with the first soft spring through the coupler means so that the length of the first soft spring is selectively increased by moving the spring adjustment means one way and the length on the first soft spring is selectively decreased by moving the spring adjustment means in an opposite way.

Defined in detail for a second embodiment, the present invention is a coil spring system to be used within a leg of a bicycle fork comprising: (a) a first soft spring with a first and second end having a given height when in the fully extended condition, and a second firm spring with a first and second end having a greater height than the first soft spring; (b) a coupler assembly comprising a coupler and a threaded bolt, the coupler having a first and second end including an internally threaded bore and a transverse outer ring located at the middle of the coupler, the transverse ring having a first surface and a second surface wherein the first soft spring at its first end rests below the second surface and the second firm springs at its second end rests on the first surface, the second firm spring positioned above the first soft spring so that a the first end of the second firm spring rests adjacent a top end of the vehicle fork leg, the threaded bolt having a first and second end including a central bore with a non-round opening at the first end, the threaded bolt being threadedly received at the center of the coupler; (c) a non-round shaped shaft having a length at least equal to the height of the first soft spring, the non-round shaped shaft having a top portion and a bottom portion, the bottom portion of the shaft inserted within the central bore with the non-round opening of the coupler member such that the threaded bolt is centrally positioned within the first soft spring; (d) an adjustment knob having a knob, a top fastening portion for mounting the knob onto a top of the leg of the bicycle fork and a lower retaining portion for fixedly retaining the top portion of the non-round shaped shaft; (e) a compression rod system including the first soft spring retained at the top of the compression rod system, the first soft spring and the second firm spring and the coupler member and the non-round shaped shaft and the compression rod system resting within the leg of the bicycle fork; and (f) the spring compression range of the first soft spring is selectively increased by turning the knob in one direction to cause rotation of the threaded bolt which further moves the coupler away from the knob to thereby increase the height of the first soft spring and the spring compression range of the first soft spring is selectively decreased by rotating the knob in the opposite direction to cause the coupler to move closer to the knob to thereby decrease the height of the first soft spring.

For the second embodiment, defined alternatively more broadly, the present invention is a coil spring system to be used within a leg of a bicycle fork, comprising: (a) a first soft spring having a given length when in the fully extended condition and having a first end and a second end, and a second firm spring having greater length than the first soft spring and having a first and second end, the first soft spring positioned adjacent the bottom of the second firm spring so that the first end of the first soft spring rests adjacent the second end of the second firm spring and the first end of the second firm spring rests adjacent a top end of the bicycle fork leg, both springs resting within the leg of the bicycle fork; (b) a coupler assembly comprising a threaded bolt threadedly received with a coupler, the coupler is placed between the first and second spring; and (c) a spring adjustment means retained on the bicycle fork at a location adjacent the top of the fork leg and in communication with the first soft spring through the coupler so that the length of the first soft spring is selectively increased by moving the spring adjustment means in one direction and the length on the first soft spring is selectively decreased by moving the spring adjustment means in the opposite direction.

For the second embodiment, defined most broadly, the present invention is a coil spring damping system to be used within a leg of a vehicle fork, comprising: (a) a first soft spring with a first and second end having a given length when in the fully extended condition, and a second firm spring with a first and second end having a greater spring length than the first soft spring, the first soft spring positioned adjacent the bottom of the second firm spring so that the first end of the first soft spring rests adjacent a second end of the second firm spring and the first end of the second firm spring rests adjacent a top end of the vehicle fork leg, both springs resting within the leg of the vehicle fork; (b) a coupler means is placed between the first and second springs; and (c) a spring adjustment means retained on the vehicle fork leg at a location adjacent the top of the fork leg and in communication with the first soft spring through the coupler means so that the length of the first soft spring is selectively increased by moving the spring adjustment means one way and the length on the first soft spring is selectively decreased by moving the spring adjustment means in an opposite way.

For a third embodiment defined in detail, the present invention is a coil spring system to be used within a leg of a bicycle fork comprising: (a) a first soft spring with a first and second end having a given height when in the fully extended condition, and a second firm spring with a first and second end having a greater height than the first soft spring; (b) a coupler assembly comprising a coupler and a threaded bolt, the coupler having a first and second end including an internally threaded bore and a transverse outer ring located at the middle of the coupler, the transverse ring having a first surface and a second surface wherein the first soft spring at its first end rests below the second surface and the second firm springs at its second end rests on the first surface, the first soft spring positioned below the second firm spring so that a the second end of the first soft spring rests adjacent a bottom end of the vehicle fork leg, the threaded bolt having a first and second end including a central bore with a non-round opening at the first end, the threaded bolt being threadedly received at the center of the coupler; (c) a non-round shaped shaft having a length at least equal to the height of the first soft spring, the non-round shaped shaft having a top portion and a bottom portion, the bottom portion of the shaft inserted within the central bore with the non-round opening of the coupler member such that the threaded bolt is centrally positioned within the first soft spring; (d) an adjustment knob having a knob, a fastening portion for mounting the knob onto a bottom of the leg of the bicycle fork and a lower retaining portion for fixedly retaining a portion of the non-round shaped shaft;(e) a compression rod system including the second firm spring retained below the compression rod system, the first soft spring and the second firm spring and the coupler member and the non-round shaped shaft and the compression rod system resting within the leg of the bicycle fork; and (f) the spring compression range of the first soft spring is selectively increased by turning the knob in one direction to cause rotation of the threaded bolt which further moves the coupler away from the knob to thereby increase the height of the first soft spring and the spring compression range of the first soft spring is selectively decreased by rotating the knob in the opposite direction to cause the coupler to move closer to the knob to thereby decrease the height of the first soft spring.

For the third embodiment, defined more broadly, the present invention is a coil spring system to be used within a leg of a bicycle fork, comprising: (a) a first soft spring having a given length when in the fully extended condition and having a first end and a second end, and a second firm spring having greater length than the first soft spring and having a first and second end, the first spring positioned adjacent a bottom of the second firm spring so that the first end of the first soft spring rests adjacent to the second end of the second firm spring and the second end of the first soft spring rests adjacent a bottom end of the bicycle fork leg, both springs resting within the leg of the bicycle fork; (b) a coupler assembly comprising a threaded bolt threadedly received with a coupler, the coupler is placed between the first and second springs; and (c) a spring adjustment means retained on the bicycle fork at a location adjacent a bottom of the fork leg and in communication with the first soft spring through the coupler so that the length of the first soft spring is selectively increased by moving the spring adjustment means in one direction and the length on the first soft spring is selectively decreased by moving the spring adjustment means in the opposite direction.

For the third embodiment, defined most broadly, the present invention is a coil spring damping system to be used within a leg of a vehicle fork, comprising: (a) a first soft spring with a first and second end having a given length when in the fully extended condition, and a second firm spring with a first and second end having greater spring length than the first soft spring, the first soft spring positioned adjacent a bottom of the second firm spring so that the first end of the first soft spring rests close to a second end of the second firm spring and the second end of the first soft spring rests adjacent a bottom end of the vehicle fork leg, both springs resting within the leg of the vehicle fork; (b) a coupler means is placed between the first and second spring; and (c) a spring adjustment means retained on the vehicle fork leg at a location adjacent the bottom of the fork leg and in communication with the first soft spring through the coupler means so that the length of the first soft spring is selectively increased by moving the spring adjustment means one way and the length on the first soft spring is selectively decreased by moving the spring adjustment means in an opposite way.