Patent Description:
Bicycles have been used for recreation, transportation, and sporting competition for decades, and can be found in all types of environments (e.g., urban, suburban, and rural). What started out as a relatively simple assembly of components has evolved into more complex forms as bicycles have been adapted from general use (e.g., transportation, exercise) to more specific niches (e.g., Olympic-style track racing, BMX-style racing, cross-country cycling, etc.).

As bicycle use has changed, the cycling industry has adapted and improved various components of the bicycle in order to meet the evolving needs of the cycling public. A bicycle rear derailleur is one such component. The purpose of a rear derailleur is to assist in changing the speed of a bicycle by selectively moving a bicycle chain between gears of a cassette located near a rear wheel of the bicycle. A typical rear derailleur has a base member connected to the bicycle near the rear wheel, a chain cage (or chain guide) engaging the bicycle chain, and a movable member connecting the base member and the chain cage so as to move the chain cage laterally relative to the base member. Movement of the chain cage moves the bicycle chain between the gears of the gear cassette. A rider is able to shift gears due to a shift control device (or shifter) mounted on or near the bicycle's handlebar. One end of a control cable running down the length of the bicycle is connected to the shift control device and the other end of the control cable is connected the rear derailleur. The shift control device adjusts the amount of tension on the control cable. The shift control device allows the rider to pull (increase tension) or release (decrease tension) the control cable. An increase or decrease in tension on the control cable determines the direction on the gear cassette in which the bicycle chain moves (i.e., from lower gear to higher gear or from higher gear to lower gear). Increasing tension on the control cable causes the chain cage to laterally move in one direction relative to the base member (which, in turn, moves the bicycle chain in that same direction), while releasing tension on the control cable causes the chain cage to laterally move in another direction relative to the base member (generally the opposite direction the chain cage moves in when tension is increased). Thus, the chain cage (and bicycle chain) can be moved laterally by increasing or decreasing tension on the control cable.

During use, a bicycle can be ridden over a variety of surfaces and terrains including, without limitation, smooth surfaces (e.g., paved surfaces), rough surfaces (e.g., dirt roads, off-road terrain), and the like that can subject the bicycle to various conditions including, without limitation, bouncing, vibration, and the like. There may be hazards including, without limitation, potholes, rocks, and the like. These various conditions and hazards can impact the bicycle in various ways including, without limitation, causing a bicycle rider to crash, causing the bicycle chain to become disengaged from the gear cassette, causing the control cable to become disconnected from the rear derailleur, or the like. For example, when the bicycle is moving on a rough surface, uncontrolled movement of the chain cage can result in the chain cage moving back and forth between the direction of chain tensioning and in the opposite direction. This can result in the bicycle chain bouncing to the extent the bicycle chain becomes disengaged from a portion of the chain cage (e.g., the drive sprocket or front chain ring) and/or the gear cassette.

Different types of rear derailleurs have been proposed to address uncontrolled movement of the chain cage that could result in the chain cage moving back and forth between the direction of chain tensioning and in the opposite direction. However, such rear derailleurs have their limitations and can always be improved.

Accordingly, there is a need for an improved rear derailleur to control movement of the chain cage back and forth between the direction of chain tensioning and in the opposite direction. There is a further need for an improved rear derailleur to reduce movement of the chain cage back and forth between the direction of chain tensioning and in the opposite direction. There is also a need for a rear derailleur that can mitigate the effects of various conditions and hazards that can impact engagement of the bicycle chain and the rear derailleur. There is an additional need for a rear derailleur that is easier to manufacture, assemble, adjust, and maintain. The present invention satisfies these needs and provides other related advantages.

<CIT>, which shows the preamble of claim <NUM>, describes that a rear derailleur includes a base member mountable to a bicycle frame, a movable member movably coupled to the base member, and a pivot member rotatably coupled to the movable member. The rear derailleur also includes a chain guide assembly rotatably connected to the movable member via the pivot member. The rear derailleur includes a damper device disposed within the movable member. The damper device is operable to apply a damping force to the chain guide assembly when the chain guide assembly rotates. The damper device includes a friction member having a friction surface. A first portion of the friction surface is in frictional engagement with the pivot member, and a second portion of the friction surface is in frictional engagement with the movable member. The friction device is disposed within the movable member at a distance relative to the biasing device in an axial direction along the pivot member.

<CIT> describes that a bicycle rear derailleur includes a movable member and a chain guide assembly rotatably connected to the movable member. The bicycle rear derailleur also includes a pivot member non-rotatably coupled to the chain guide assembly and having an outer annular surface, a biasing device configured to bias the chain guide assembly in a first rotational direction relative to the movable member, and a damper device disposed between the chain guide assembly and the movable member. The damper device is operable to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction relative to the movable member. The damper device includes a friction device that is radially inner relative to the biasing device. The friction device includes a friction member having at least one friction surface biased against and in frictional engagement with the pivot member.

An improved rear derailleur that can maintain tension on the bicycle chain. An improved rear derailleur that can mitigate the effects of various conditions and hazards that can impact engagement of the bicycle chain and the rear derailleur is provided. An improved rear derailleur that is easier to manufacture, assemble, adjust, and maintain is provided.

As discussed above, a rear derailleur of a bicycle includes a chain cage (chain guide) that maintains tension on the bicycle chain. The chain cage (chain guide) is coupled to a movable member. In order to maintain function of the drive system, the bicycle chain must have proper tension to stay seated on the pulleys (cogs) of the chain cage when the bicycle hits a bump on a surface. However, if there is no damper in the system, the chain cage (chain guide) may rotate beyond a reasonable amount in certain rough conditions. A reasonable amount is defined as the point where the bicycle chain will not become unseated from the pulleys (cogs). When the bicycle chain becomes unseated from the pulleys (cogs), the bicycle chain can "derail," making the drive system inoperable. To maintain a reasonable amount of chain guide rotation, a damper assembly is added to the system. The damper assembly is coupled to both the movable member and the chain guide. The damper assembly functions in a way that controls movement of the chain cage back and forth between the direction of chain tensioning and in the opposite direction.

The present invention is a rear derailleur assembly for mounting to a bicycle, as defined in claim <NUM>.

Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the scope of the invention.

The various present embodiments now will be discussed in detail with an emphasis on highlighting the advantageous features with reference to the drawings of various embodiments. The illustrated embodiments are intended to illustrate, but not to limit the invention. These drawings include the following figures, in which like numerals indicate like parts:.

The following detailed description describes the present embodiments, with reference to the accompanying drawings. In the drawings, reference numbers label elements of the present embodiments. These reference numbers are reproduced below in connection with the discussion of the corresponding drawing features.

It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for the purpose of clarity, many other elements found in rear derailleurs. Those of ordinary skill in the pertinent arts may recognize that other elements and/or steps are desirable and/or required in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein. The disclosure herein is directed to all such variations and modifications to such elements and methods known to those skilled in the pertinent arts.

As shown in <FIG> for purposes of illustration, a first embodiment of the present invention resides in a rear derailleur assembly <NUM> that can be engaged to a frame <NUM> of a bicycle near a rear wheel (not shown) of the bicycle. A side of the rear derailleur assembly <NUM> facing the frame <NUM> may be referred to as an inward or inner side while an opposite side of the rear derailleur assembly <NUM> may be referred to as an outward or outer side. The rear derailleur assembly <NUM> is capable of moving a bicycle chain <NUM> laterally between gears (or sprockets or cogs) of a cassette <NUM> connected to the frame <NUM>. The bicycle includes a control cable <NUM> extending between front and rear portions of the bicycle. The control cable <NUM> can be in the form of various cables including, without limitation, a Bowden-type control cable having an outer sheath and an inner wire. One end of the control cable <NUM> is connected to a shift control device (not shown) mounted on or near the bicycle's handlebar (not shown) at the front of the bicycle. The other end of the control cable <NUM> is connected to the rear derailleur assembly <NUM>. As outlined above, tension on the control cable <NUM> affects movement of the bicycle chain <NUM> between gears (or sprockets or cogs) of the cassette <NUM> by controlling operation of the rear derailleur assembly <NUM>.

The rear derailleur assembly <NUM> includes an upper body assembly <NUM> that acts as a base member by connecting the rear derailleur assembly <NUM> to a rear drop-out or rear axle holder (not shown) of the bicycle frame.

The rear derailleur assembly <NUM> also includes a chain guide (or chain cage) assembly <NUM> that engages the bicycle chain and moves the bicycle chain <NUM> from one gear of the cassette <NUM> to another gear of the cassette <NUM>.

The rear derailleur assembly <NUM> further includes a controller assembly <NUM> operationally connecting the upper body assembly <NUM> to the chain cage assembly <NUM>. As described in more detail below, movement of the controller assembly <NUM> causes movement of the chain cage assembly <NUM> which, in turn, moves the bicycle chain <NUM> between gears of the cassette <NUM>.

The rear derailleur assembly <NUM> additionally includes a lower body assembly <NUM> that acts as a moveable member operationally connecting the controller assembly <NUM> to the chain cage assembly <NUM>. The lower body assembly <NUM> also operationally connects the upper body assembly <NUM> to the chain cage assembly <NUM> due to the controller assembly <NUM> operationally connecting the upper body assembly <NUM> to the lower body assembly <NUM>.

The upper body assembly <NUM> includes an upper body portion <NUM>, a mounting bolt (or fixing bolt) <NUM> extending through a bore in the upper body portion <NUM> for threadedly securing the rear derailleur assembly <NUM> to the bicycle frame <NUM>, and a cable stay member <NUM>.

The cable stay member <NUM> acts as a support for the control cable <NUM>. The cable stay member <NUM> and extends away from the upper body portion <NUM> to receive the control cable <NUM>. The cable stay member <NUM> includes a cable guide bore through which the control cable <NUM> passes to be connected to the rear derailleur assembly <NUM>. Openings on opposite sides of the cable guide bore can be the same size or different sizes, depending on the type of control cable used. For example, when the control cable <NUM> is in the form of a Bowden-type control cable having an outer sheath and an inner wire, the opening of the cable guide bore on an inward side of the rear derailleur assembly <NUM> receiving the control cable <NUM> may be sized and shaped to receive the outer sheath of the control cable <NUM> (e.g., the diameter of the opening of the cable guide bore may be larger than or at least large enough for press-fit engagement with the outer surface of the outer sheath of the control cable <NUM>), while the opening of the cable guide bore on an outward side of the rear derailleur assembly <NUM> from which the control cable <NUM> extends may be sized and shaped to allow only an inner wire <NUM> of the control cable <NUM> to pass through the opening on the outward side of the rear derailleur assembly <NUM>.

The chain cage (or chain guide) assembly <NUM> includes a chain cage that includes a pair of spaced apart, parallel cage plates (also referred to as inner and outer <NUM> cage plates or inner and outer <NUM> cage guides) with a pair of pulleys (or sprockets or jockey wheels) (i.e., an upper guide pulley and a lower idler (or tension) pulley) disposed therebetween. The inner plate and the outer plate <NUM> are joined together at an upper end by a first pivot shaft, and joined together at a lower end by a second pivot shaft. The upper guide pulley is rotatably mounted on the first pivot shaft between the cage plates. The lower idler pulley is pivotally mounted on the second pivot shaft between the cage plates. The inner cage plate and the outer cage plate <NUM> may be made from various materials including, without limitation, durable cold-forged aluminum, molded plastic, a composite material, or the like. The pulleys may include sealed precision pulley bearings to reduce friction and avoid contamination.

The lower body assembly <NUM> includes a lower body portion (movable member) <NUM> operationally connected to the chain cage assembly <NUM>. The inner plate of the chain cage assembly <NUM> is the cage plate closest to the bicycle frame <NUM>, and the outer plate <NUM> of the chain cage assembly <NUM> is the cage plate closest to the lower body portion <NUM>. The bodies of the upper and lower body assemblies <NUM>, <NUM> may be made from various materials including, without limitation, a carbon fiber/nylon composite material; aluminum; plastic or the like.

As stated above, the controller assembly <NUM> operationally connects the chain cage assembly <NUM> to the upper body assembly <NUM>. The controller assembly <NUM> includes a controller including an upper link portion (or upper pivot bar or inner pivot bar) and a lower link portion (or lower pivot bar or inner pivot bar) spaced apart from one another that acts as a linkage assembly for connecting the upper and lower body assemblies <NUM>, <NUM>. The upper link portion is pivotally connected at one end to the upper body portion <NUM> by a pivot pin or the like. The lower link portion is pivotally connected at one end to the upper body portion <NUM> by a pivot pin or the like. The upper and lower body portions <NUM>, <NUM> are part of the controller assembly <NUM>. The upper link portion is pivotally connected to the lower body portion <NUM> at an end opposite the end pivotally connected to the upper body portion <NUM>. The lower link portion is pivotally connected to the lower body portion <NUM> at an end opposite the end pivotally connected to the upper body portion <NUM>.

The controller assembly <NUM> includes a spring (not shown) operationally engaging the controller (i.e., the upper and lower link portions). The spring is operationally connected to the upper and lower link portions to normally bias the upper and lower link portions in a first direction such that the lower body portion <NUM> is normally biased outwardly away from the bicycle frame <NUM> relative to the upper body portion <NUM> engaging the bicycle frame <NUM>. In operation, the upper and lower link portions generally form a parallelogram with the upper and lower body portions <NUM>, <NUM>; the parallelogram rotating about the several pivot pins or the like connecting the upper and lower body portions <NUM>, <NUM> as the spring expands and contracts between strained and unstrained configurations. As the spring is strained and expands, the parallelogram rotates about the several pivot pins or the like. The spring biases the chain cage assembly <NUM> to an innermost or outermost position relative to the gears of the cassette <NUM>. A high limit adjustment screw (or outer limit screw) and a low limit adjustment screw (or lower limit screw) are used to adjust the range the parallelogram rotates about the several pivot pins or the like so that chain cage assembly <NUM> be positioned over no more than the highest gear and no less than the lowest gear. Turning the limit screws adjusts the limit of travel of the pulleys. Tightening the limit screws restricts the travel, while loosening the limit screws allows more travel. The purpose of the adjusting the limit screws is to find the tightest high limit screw setting that will allow a good shift to the outermost gear (i.e., the smallest in size) on the cassette, and the tightest lower limit screw setting that will allow a good shift to the innermost gear (i.e., the largest in size) on the cassette. The high limit screw is used to adjust the rear derailleur assembly <NUM> such that the upper pulley is centered with the center of the highest gear. An angle adjustment screw (or B-adjustment screw) is used to adjust the rear derailleur assembly <NUM> such that there are <NUM>-<NUM> in-between the top of the upper pulley and the bottom of the lowest gear on the cassette <NUM>.

In use, the control cable <NUM> for actuating the rear derailleur assembly <NUM> passes through the cable bore in the cable stay <NUM> to operationally engage an end of the actuating arm. Tension on the control cable causes relative movement between the upper body portion <NUM> and the lower body portion <NUM>, moving the upper and lower link arms in a second direction opposite the first direction where the lower body portion <NUM> and the chain cage assembly <NUM> are normally biased outwardly away from the bicycle frame <NUM>, and moving the lower body portion <NUM> and the chain cage assembly <NUM> laterally towards the bicycle frame <NUM>. As stated above, the amount of tension on the control cable <NUM> determines which direction the bicycle chain <NUM> will move in (i.e., from lower gear to higher gear or from higher gear to lower gear). The shift control device (not shown) allows the rider of the bicycle to pull (increase tension) or release (decrease tension) the control cable <NUM>. With the control cable <NUM> (e.g., an inner wire if the control cable is a Bowden-type cable), the chain cage assembly <NUM> can be moved laterally by moving the controller assembly <NUM> via the amount of tension on the inner wire. When the shift control device is operated by the rider, tension on the inner wire of the control cable <NUM> is pulled or released. Pulling the inner wire <NUM> (i.e., increasing tension on the inner wire <NUM>) of the control cable <NUM> moves the chain cage assembly <NUM> against the biasing force of the spring, while releasing the inner wire <NUM> (i.e., decreasing tension on the inner wire <NUM>) causes the chain cage assembly <NUM> to move due to the biasing force of the spring. Increasing tension on the control cable <NUM> causes the chain cage assembly <NUM> to move in one direction (which, in turn, moves the bicycle chain <NUM> in that same direction), while releasing tension on the control cable <NUM> causes the chain cage assembly <NUM> to move in another direction (generally the opposite direction the chain cage assembly <NUM> moves in when tension is increased). Thus, the chain cage assembly <NUM> (along with the bicycle chain <NUM>) can be moved laterally by increasing or decreasing tension on the control cable <NUM>. When the control cable <NUM> is pulled (i.e., tension increased), the upper and lower link portions pivot inwardly against the force of the spring so as to move the chain cage assembly <NUM> inwardly towards the bicycle frame <NUM> which, in turn, moves the bicycle chain <NUM> from one gear to another on the cassette <NUM>. When the control cable <NUM> is released (i.e., tension decreased), the upper and lower link portions pivot outwardly, pulled by the force of the spring, so as to move the chain cage assembly <NUM> outwardly away from the bicycle frame <NUM> which, in turn, moves the bicycle chain <NUM> from one gear to another on the cassette <NUM>.

In the alternative, the rear derailleur assembly may be an electric derailleur that does not use a mechanical cable (housing included (e.g., a Bowden-type control cable)), cable stay member <NUM>, or high-force parallelogram spring to control movement of the chain cage assembly <NUM>. Instead, an electro-mechanical derailleur utilizes an electric motor (the electric motor may or may not be connected to a reduction gearbox) that, when given power, moves the chain cage assembly <NUM> into a new gear position. Similarly, the mechanical shifting mechanism (or shifter) is also replaced with an electronic version that has a series of buttons that allow the user to control movement of the chain cage assembly <NUM>. Furthermore, an electro-mechanical derailleur can be either what is called wired or wireless. For example, a wired electro-mechanical derailleur works in conjunction with an electronic shifting mechanism (or shifter) that sends a signal to the rear derailleur assembly through a set of wires electromechanically interconnecting the shifter and rear derailleur assembly. The signals from the shifter communicate a gear shift to the rear derailleur assembly. A wireless electromechanical shifter is a shifter that sends a signal through a wireless protocol to the rear derailleur to shift the gear. The shifter and derailleur are able to send/receive wireless signals from one another. There is also a battery or other power source that will either be attached to the rear derailleur assembly, the shifter, or mounted to the bicycle frame <NUM>.

The lower body portion <NUM> is rotatably secured to the outer cage plate <NUM> (i.e., the cage plate closest to lower body portion <NUM>), with the entire cage assembly <NUM> having limited rotation about a pivot axis <NUM> relative to the lower body portion <NUM>, as illustrated by arrow <NUM>. As discussed in more detail below, the chain cage assembly <NUM> is spring-loaded about the pivot axis <NUM> in one direction of rotation, and there is a limited range of rotation between the chain cage assembly <NUM> and the lower body portion <NUM>.

As discussed above, the rear derailleur assembly <NUM> includes a chain cage assembly <NUM> that maintains tension on the bicycle chain <NUM>. The chain cage assembly <NUM> is coupled to the lower body portion (movable member) <NUM>. In order to maintain function of the drive system, the bicycle chain <NUM> must have proper tension to stay seated on the pulleys (cogs) of the chain cage assembly <NUM> when the bicycle hits a bump on a surface the bicycle is riding over. However, if the assembly <NUM> lacks a dampening mechanism or damper, the chain cage assembly <NUM> may rotate relative to the lower body portion <NUM> beyond a reasonable amount in certain rough conditions. A "reasonable amount" is defined as the point where the bicycle chain <NUM> will not become unseated from the pulleys (cogs) of the chain cage assembly <NUM>. To maintain a reasonable amount of rotation of the chain cage assembly <NUM> relative to the lower body portion <NUM>, the assembly <NUM> includes a damper assembly (clutch assembly, damping assembly, dampening assembly, dampening mechanism, or damping arrangement) <NUM> for pivotal movement of the chain cage assembly <NUM> that creates friction to slow or reduce rotation speed of the chain cage assembly <NUM> around the pivot axis <NUM> in an opposite direction of rotation from the direction of rotation provided by the force of the spring-load. In this manner, the damper assembly <NUM> provides rotational resistance to pivotal movement of the chain cage assembly <NUM> caused by, for example, the bicycle hitting a bump on the surface the bicycle is riding over. The damper assembly <NUM> reduces angular acceleration in the direction the bicycle chain <NUM> is pulling as the chain cage assembly <NUM> moves forward and the damper assembly <NUM> provides no resistance as the chain cage assembly <NUM> travels back. Thus, in the direction of rotation provided by the spring-load, there is no damping provided by the damper assembly <NUM>. The damper assembly <NUM> is located in a knuckle portion <NUM> (also known as a "P Knuckle") of the lower body portion <NUM>. The knuckle portion <NUM> includes a generally cylindrical recess or bore <NUM>. The damper assembly <NUM> is housed within the bore <NUM> of the knuckle <NUM> of the lower body portion <NUM>.

The damper assembly <NUM> includes a central shaft (central axle) (also known as an input shaft or cage shaft) <NUM> (the pivot axis <NUM> runs through a central longitudinal axis of the input shaft <NUM> and, by extension, the damper assembly <NUM>), a friction clutch or spring clutch <NUM> (e.g., a coil spring or the like, such as a helical spring, an extension spring, a torsion spring, a compression spring, etc.), a clutch cap <NUM>, and a cap (also known as a "P cap") <NUM>. A first bushing <NUM> (or P cap bushing) is disposed between the central shaft <NUM> and the cap <NUM>, with a loose fit around the central shaft <NUM> and press fit to the cap <NUM>. A second bushing <NUM> is disposed between the central shaft <NUM> and the knuckle <NUM>, with a loose fit around the central shaft <NUM> and press fit to the knuckle <NUM>. The spring clutch <NUM> is disposed about the central shaft <NUM> and aligned with the central shaft <NUM> along the pivot axis <NUM>, with the clutch cap <NUM> also disposed about the spring clutch <NUM> with a portion of the central shaft <NUM> extending through a central aperture <NUM> of the clutch cap <NUM>. There is no contact between the inner diameter of the spring clutch <NUM> and the outer diameter of the central shaft <NUM>. The spring clutch <NUM> is press-fit with the clutch cap <NUM> and the knuckle <NUM>. As seen in <FIG>, more of the length of the outer diameter of the spring clutch <NUM> press-fit engages the inner diameter of the knuckle <NUM> than engages the inner diameter of the clutch cap <NUM>. The central aperture <NUM> is sized and shaped to correspond to the size and shape of the exterior perimeter of the central shaft <NUM> such that the clutch cap <NUM> cannot be rotated relative to the central shaft <NUM>. In the alternative, the aperture <NUM> can be press-fit with the exterior perimeter of the central shaft <NUM> such that the clutch cap <NUM> cannot be rotated relative to the central shaft <NUM> or the press-fit provides rotational resistance to rotation of the clutch cap <NUM> relative to the central shaft <NUM>. As illustrated, pair of fasteners <NUM> (e.g., screws) secure the cap <NUM> to the knuckle <NUM>. Each fastener <NUM> extends through a particular bore <NUM> on the knuckle <NUM>, and through a particular bore <NUM> on the cap <NUM> aligned with the bore <NUM> on the knuckle <NUM> to securably fasten the cap <NUM> to the knuckle <NUM> and enclose the damper assembly <NUM> by covering the opening to the bore <NUM> of the knuckle <NUM>.

A fastener <NUM> (e.g., a screw) extends through an aperture <NUM> in the outer plate <NUM> to secure the second bushing <NUM> between the outer plate <NUM> and the knuckle <NUM>. The fastener <NUM> extends into a bore <NUM> of the central shaft <NUM> to secure the outer plate <NUM>, second bushing <NUM>, and central shaft <NUM> together. The central shaft <NUM> also includes another bore on the opposite end of the shaft <NUM> to save weight, and with a hex area configured for insertion of a tool to hold the shaft <NUM> while the fastener <NUM> is being turned on the other end of the shaft <NUM> to engage the core <NUM>.

In operation, when the outer cage plate <NUM> rotates in a counter-clockwise direction or first direction (clutch engaged mode) along arrow <NUM> as seen from the outward side, the outer cage plate <NUM>, the central shaft <NUM>, and the clutch cap <NUM> will move together. The spring clutch <NUM> is generally fixed relative to the knuckle <NUM>. However, as the spring clutch <NUM> is press-fit with the clutch cap <NUM> and the knuckle <NUM>, rotation of the clutch cap <NUM> will rotate the spring clutch <NUM> a few degrees (e.g., five (<NUM>) to twenty (<NUM>) degrees). The number of degrees is determined by a ratio dependent on the torque setting (e.g., more torque will be more degrees). Rotation of the spring clutch <NUM> is then stopped by frictional contact between the outer diameter of the spring clutch <NUM> and the knuckle <NUM>. Rotation of the spring clutch <NUM> makes the outer diameter of the spring clutch <NUM> a bit bigger to press even tighter against the knuckle <NUM> and the clutch cap <NUM>. This generates increased friction torque between the clutch cap <NUM> and the outer diameter of the spring clutch <NUM> (as well as between the knuckle <NUM> and the outer diameter of the spring clutch <NUM>). That is, the outer diameter of the spring clutch <NUM> applies a normal force to the respective inner diameters of the clutch cap <NUM> and the knuckle <NUM>. As the normal force increases, the resistant torque is also increased in proportion. At some point, the resistant torque is sufficient to prevent movement of the chain cage assembly in the first direction. The dampening effect is changed by changing the normal force applied to the respective inner diameters of the clutch cap <NUM> and the knuckle <NUM> by the outer diameter of the spring clutch <NUM>. The spring clutch <NUM> acts as a clutch due to the change in the outer diameter of the spring clutch <NUM>.

When outer cage plate <NUM> rotates in a clockwise direction or second direction (clutch disengaged mode) along arrow <NUM> as seen from the outward side, the outer cage plate <NUM>, the central shaft <NUM>, and the clutch cap <NUM> will move together. The spring clutch <NUM> is generally fixed on the knuckle <NUM>, with no rotation of the knuckle <NUM>. However, the clutch cap <NUM> will rotate the spring clutch <NUM> a few degrees by friction that makes the outer diameter of the spring clutch <NUM> a bit smaller. This, in turn, makes the friction torque (between the engaged clutch cap <NUM> and outer diameter of the spring clutch <NUM> as well as between the engaged knuckle <NUM> and the outer diameter of the spring clutch <NUM>) much smaller than the friction between them when the outer diameter of the spring clutch <NUM> is larger. In this manner, the spring clutch <NUM>, via the chain cage assembly <NUM>, applies a sufficient tension to the bicycle chain <NUM>. The damper assembly <NUM> changes the acceleration of the chain cage assembly <NUM> about the pivot axis <NUM> but the acceleration is not always uniform due to differences in terrain (i.e., there will be different accelerations of the chain cage assembly <NUM> as acceleration is affected by the type of terrain the user is riding on, with different terrains causing different accelerations).

As shown in <FIG> for purposes of illustration, a second embodiment of the present invention resides in a damper assembly <NUM> where the spring clutch <NUM> mostly engages the clutch cap <NUM> (rather than the knuckle <NUM>) due to the clutch cap <NUM> being greater in length along the pivot axis <NUM>. As such, more of the length of the outer diameter of the spring clutch <NUM> press-fit engages the inner diameter of the clutch cap <NUM> than engages the inner diameter of the knuckle <NUM>. In operation, when the outer cage plate <NUM> rotates in a counter-clockwise direction (clutch engaged mode), the outer cage plate <NUM>, the central shaft <NUM>, the spring clutch <NUM>, and the clutch cap <NUM> will move together. The spring clutch <NUM> is fixed on the clutch cap <NUM> so there is no relative rotation at the clutch cap <NUM>. However, the knuckle <NUM> is static, and that will make the spring clutch <NUM> rotate a few degrees (e.g., five (<NUM>) to twenty (<NUM>) degrees). The number of degrees is determined by a ratio dependent on the torque setting (e.g., more torque will be more degrees). Rotation of the spring clutch <NUM> is then stopped by friction that makes the outer diameter of the spring clutch <NUM> a bit bigger. This, in turn, generates friction torque between the knuckle <NUM> and the outer diameter of the spring clutch <NUM>. When outer cage plate <NUM> rotates in a clockwise direction (clutch disengaged mode), the outer cage plate <NUM>, the central shaft <NUM>, the spring clutch <NUM>, and the clutch cap <NUM> will move together. The spring clutch <NUM> is fixed on the clutch cap <NUM>, with no relative rotation of the clutch cap <NUM> with the spring clutch <NUM>. However, the knuckle <NUM> is static, and rotation of the spring clutch <NUM> with the clutch cap <NUM> will make the spring clutch <NUM> rotate a few degrees and then stop (e.g., the spring clutch <NUM> stops when the chain cage torque is bigger than the friction torque), with the outer diameter of the spring clutch <NUM> a bit smaller. This, in turn, makes the friction torque between the knuckle <NUM> and the outer diameter of the spring clutch <NUM> much smaller when disengaged than the friction torque between the knuckle <NUM> and the spring clutch <NUM> when engaged.

An advantage of this damper assembly <NUM> as compared to others is that this damping assembly <NUM> uses fewer parts and requires no additional friction-producing elements to be aligned or fixed in place. The damper assembly <NUM> is also lightweight and simple for manufacturing.

In addition, the claimed invention is not limited in size and may be constructed in various sizes in which the same or similar principles of operation as described above would apply. Furthermore, the figures (and various components shown therein) of the specification are not to be construed as drawn to scale.

In other words, unless explicitly stated to the contrary, embodiments "comprising" or "having" an element or a plurality of elements having a particular property can include additional elements not having that property. In other words, the terms "comprises," "comprising," "including," and "having," are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. In other words, the use of "including," "comprising," "having," "containing," "involving," and variations thereof, is meant to encompass the items listed thereafter and additional items. Further, references to "one embodiment" or "one implementation" are not intended to be interpreted as excluding the existence of additional embodiments or implementations that also incorporate the recited features. The term "exemplary" is intended to mean "an example of".

In other words, an element or step recited in the singular and preceded by the word "a" or "an" should be understood as not necessarily excluding the plural of the elements or steps. Further, references to "one embodiment" or "one implementation" are not intended to be interpreted as excluding the existence of additional embodiments or implementations that also incorporate the recited features. Thus, when introducing elements of aspects of the disclosure or the examples thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. In other words, the indefinite articles "a", "an", "the", and "said" as used in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean "at least one. " The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary. Any range or value given herein can be extended or altered without losing the effect sought, as will be apparent to the skilled person.

While various spatial and directional terms, such as "top," "bottom," "upper," "lower," "vertical," and the like are used to describe embodiments and implementations of the present disclosure, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations can be inverted, rotated, or otherwise changed, such that a top side becomes a bottom side if the structure is flipped <NUM> degrees, becomes a left side or a right side if the structure is pivoted <NUM>°, and the like. In other words, spatially relative terms, such as "front," "rear," "left," "right," "inner," "outer," "beneath", "below", "lower", "above", "upper", "horizontal", "vertical", "lateral", "longitudinal" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures.

It will be understood that the benefits and advantages described above can relate to one embodiment or can relate to several embodiments.

That is, the operations can be performed in any order, unless otherwise specified, and examples of the disclosure can include additional or fewer operations than those disclosed herein. For example, it is contemplated that executing or performing a particular operation before, contemporaneously with, or after another operation (e.g., different steps, etc.) is within the scope of aspects and implementations of the disclosure. In other words, the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance.

The phrase "one or more of the following: A, B, and C" means "at least one of A and/or at least one of B and/or at least one of C. " The phrase "and/or", as used in the specification and in the claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases.

As briefly discussed above, as used in the specification and in the claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements.

Use of ordinal terms such as "first," "second," "third," etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed. Ordinal terms are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term), to distinguish the claim elements.

It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) can be used in combination with each other. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the various embodiments of the disclosure without departing from their scope. While the dimensions and types of materials described herein are intended to define the parameters of the various embodiments of the disclosure, the embodiments are by no means limiting and are example embodiments. Many other embodiments will be apparent to those of ordinary skill in the art upon reviewing the above description. The scope of the various embodiments of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein. " Moreover, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

This written description uses examples to disclose the various embodiments of the disclosure, including the best mode, and also to enable any person of ordinary skill in the art to practice the various embodiments of the disclosure, including making and using any devices or systems and performing any incorporated methods,.

The above description presents the best mode contemplated for carrying out the present invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains to make and use this invention.

The following claims are thus to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the invention. Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope of the invention. The illustrated embodiment has been set forth only for the purposes of example and that should not be taken as limiting the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.

Various technical features of the above embodiments may be combined randomly, and in order to simplify the description, possible combinations of various technical features in the above embodiments are not all described.

Claim 1:
A rear derailleur assembly (<NUM>) for mounting to a bicycle, wherein the bicycle includes a frame (<NUM>), comprising:
an upper body portion (<NUM>) for operationally engaging the rear derailleur assembly (<NUM>) to the frame (<NUM>);
a chain cage (<NUM>) for engaging a chain (<NUM>) of the bicycle;
a controller (<NUM>) pivotally connected to the upper body portion (<NUM>);
a lower body portion (<NUM>) operationally connected to the chain cage (<NUM>), pivotally connected to the controller (<NUM>), and pivotally connected to the chain cage (<NUM>) about a pivot axis (<NUM>); and
a damper assembly (<NUM>) configured to provide increased rotational resistance as the chain cage (<NUM>) rotates in a first direction about the pivot axis (<NUM>) due to increased frictional contact between the damper assembly (<NUM>) and the lower body portion (<NUM>);
wherein the lower body portion (<NUM>) includes a recess within which the damper assembly (<NUM>) is disposed;
wherein the damper assembly (<NUM>) includes a spring (<NUM>) having an outer diameter configured to increase as the chain cage (<NUM>) rotates in the first direction about the pivot axis (<NUM>) and to decrease as the chain cage (<NUM>) rotates in a second direction about the pivot axis (<NUM>); and
characterized in that
the recess includes a surface configured to engage a portion of the spring (<NUM>) with increased frictional contact between the surface of the recess and the portion of the spring (<NUM>) as the chain cage (<NUM>) rotates in the first direction.