Patent Description:
US patent with Patent No. <CIT> discloses a damping device including a cylinder (<NUM>). The cylinder (<NUM>) is filled with a damping medium. A resilient member (<NUM>) is disposed in the cylinder (<NUM>) and a piston (<NUM>) is movably mounted in the cylinder (<NUM>). The piston (<NUM>) includes a piston body (<NUM>), a connection portion (<NUM>) connected to an end of the resilient member (<NUM>) and a neck portion (<NUM>) connected between the piston body (<NUM>) and the connection portion (<NUM>). A control valve (<NUM>) is movably mounted to the neck portion (<NUM>) of the piston (<NUM>), wherein the control valve (<NUM>) is able to control a traveling velocity of the piston (<NUM>) by closing or detaching from openings with respect to the piston body (<NUM>).

The damping device disclosed in the US patent with Patent No. <CIT> can be implemented in a wide range of use, for example, a drawer slide rail assembly of a piece of furniture or a server slide rail assembly of a rack system. The said slide rail assemblies have functions of push-open and/or self-close. Herein, the damping device facilitates decreasing a retracting speed by which the slide rail assembly (or a drawer) moves during a final step of a process where the slide rail (or the drawer) moves from an extended state (or an open state) to a retracted state (or a closed state) relative to another slide rail (or a cabinet body). For example, US patent with Patent No. <CIT> discovers a so-called push-open mechanism that facilitates the drawer, as being in a closed position, to be opened relative to the cabinet body by the drawer being pushed, and a so-called self-close mechanism that facilitates the drawer to be closed by itself during the final step of the process where the drawer is moved from an open position to a closed position. In addition, US patent with Patent No. <CIT> discovers a design where intensity of push-open mechanism can be adjusted. The said three patents are incorporated herein for references.

However, when force exerted by users to close the drawer from the open position is excessive, or when the force is continuously applied as the drawer reaches the cabinet body, the drawer may pass the closed position of the cabinet body to an over-pressed position. As a result, the drawer will be re-opened by the push-open mechanism, resulting in failure of the drawer being closed relative to the cabinet. The present invention is provided to improve the abovementioned issues.

In addition, European patent with publication number <CIT> discloses a liquid damper device by which the operation of a movable body can be silently completed due to damping, the durability of a valve body can be improved, and the characteristics in the relationship between a moving speed and a drag of a piston can be adjusted in a wider range. The liquid damper device (<NUM>) is provided with a cylinder (<NUM>) in which a silicone oil is enclosed, a piston (<NUM>) which divides the inside of the cylinder (<NUM>) into a pressure chamber (<NUM>) side and a contra pressure chamber (<NUM>) side and which is provided with a piston rod (<NUM>) which protrudes outwardly from the cylinder (<NUM>), flow passages (<NUM>) provided in the piston (<NUM>) to cause the pressure to be adjusted, and a flexible valve body (<NUM>) for the flow passages (<NUM>). The surface (<NUM>) of the piston (<NUM>) which is located on the pressure chamber (<NUM>) side and into which the flow passages open is provided with convex surface portions (<NUM>) which locally support the outer peripheral edge of the valve body (<NUM>) at two points opposite to each other in the diametric direction of the piston (<NUM>) and a concave surface portion (<NUM>) which is formed between the convex surface portions (<NUM>). The flow passages (<NUM>) open at a bottom (45a) of the concave surface portion (<NUM>).

In addition, German patent with publication number <CIT> discloses a fluid damper for movable furniture parts.

In addition, German patent with publication number <CIT> discloses a sliding arrangement for drawers, doors, etc..

In addition, European patent with publication number<CIT> discloses a device (<NUM>) for damping or decelerating the movement of parts of pieces of furniture which are movable relative to a stationary part thereof. Said device comprises a cylinder (<NUM>) inside which a piston (<NUM>) is mounted so as to be movable in a longitudinal direction and which forms working chambers (<NUM>, <NUM>) filled with a liquid damping medium on the opposite faces thereof within the cylinder, the dimensions of said working chambers being modifiable according to the position of displacement of the cylinder. The liquid damping medium can be transferred in a throttled manner between the working chambers via overflow ports (<NUM>, <NUM>) or ducts (<NUM>) which are disposed in the piston (<NUM>) and/or in the cylinder (<NUM>). A piston rod (<NUM>) which is sealingly guided out of the associated end of the cylinder is connected to one side of the piston. The movement of the part of the piece of furniture which is to be damped or decelerated is transmitted to the piston via the outer end of the piston rod (<NUM>) facing away from the piston. A volume compensating mechanism is provided for compensating the total volume of the working chambers (<NUM>, <NUM>), which changes as a result of the volume displaced by the piston rod when the same is inserted into the cylinder. The piston rod (<NUM>) is coupled to the piston that is provided with overflow ports (<NUM>) so as to be movable by a given longitudinal path while encompassing a non-return disk (<NUM>) in the end region facing the piston. Said non-return disk (<NUM>) is provided with at least one overflow port (<NUM>), has a reduced outer diameter, and is moved into sealing contact with the facing piston face during a damping or decelerating working stroke while being displaced into a position that is spaced apart from said face of the piston during a return stroke. A spring (<NUM>) which biases the facing faces of the non-return disk (<NUM>) and the piston (<NUM>) into the spaced-apart position is arranged between the non-return disk (<NUM>) and the piston (<NUM>).

In addition, German patent with publication number <CIT> discloses a piston cylinder unit (<NUM>) having a cylinder (<NUM>), in which a piston rod (<NUM>) is set up to move on-axis along a longitudinal axis (<NUM>) and is guided out in a gas-tight manner through a guiding seal arrangement on one end of the cylinder. On the other end of the cylinder, there is a connecting element with a jointed lug, a ball socket or similar. A piston (<NUM>) has a fixed link with the piston rod.

This in mind, the present invention aims at providing a movable furniture part and a damping device thereof.

This is achieved by a damping device according to claim <NUM>. The dependent claims pertain to corresponding further developments and improvements.

As will be seen more clearly from the detailed description following below, the claimed damping device includes a housing, a piston, a base, a spring and a controller. The housing has an inner wall. A chamber is defined by the inner wall and has a damping medium filled therewith, wherein the inner wall has a first inner diameter, a second inner diameter and a third inner diameter, the first inner diameter is different from the second inner diameter, the second inner diameter is different from the third inner diameter. The piston is movable in the chamber along a substantially linear direction. The piston comprising a passage configured to allow the damping medium to pass through. The base is connected to the piston through an extending portion. The base comprises a passage for allowing the damping medium to pass through. The spring is configured to provide an elastic force to one of the piston and the base. The controller is disposed between the passage of the piston and the passage of the base. The controller is movably mounted to the extending portion. The controller comprises a control member and a resilient member. The control member and the resilient member are disposed between the piston and the base. A space is defined by the control member. The space is configured to accommodate the resilient member. The control member is capable of closing a portion or all portions of the passage of the piston, wherein the resilient member is configured to provide a resilient force for the control member to no longer close the passage of the piston.

<FIG> are diagrams illustrating a damping device <NUM> according to a first embodiment of the present invention. The damping device <NUM> includes a housing <NUM>, a piston <NUM>, a base <NUM>, a control member <NUM> and a resilient member <NUM>. Preferably, the damping device <NUM> further includes an extending member <NUM> and a spring <NUM>.

The housing <NUM> has an inner wall <NUM>, and a chamber <NUM> is defined by the inner wall <NUM>. The housing <NUM> includes a bottom portion <NUM> and a top portion <NUM>. Preferably, the bottom portion <NUM> is a closed end, and the top portion <NUM> has an opening <NUM> communicating with the chamber <NUM>. Besides, the damping device <NUM> further includes a cover <NUM> configured to close the opening <NUM>.

The piston <NUM> is movable in the chamber <NUM>. Specifically, the piston <NUM> is moved in the chamber <NUM> of the housing <NUM> in a substantially linear direction. On the other hand, the extending member <NUM> is movable relative to the housing <NUM> through the piston <NUM>. Specifically, one end of the extending member <NUM> is connected to a first side 24a of the piston <NUM>, and another end of the extending member <NUM> passes through the cover <NUM> and partially extends out of the chamber <NUM>.

The base <NUM> can be moved in the chamber <NUM> with the piston <NUM>. Preferably, the base <NUM> is connected to a second side 24b of the piston <NUM>, wherein the second side 24b is opposite to the first side 24a. Besides, the base <NUM> and/or the piston <NUM> include at least one passage. Hereinafter, the base <NUM> and the piston <NUM> respectively including a plurality of passages <NUM> and a plurality of passages <NUM> are illustrative of an example, as shown in <FIG>, but the present invention is not limited thereto.

The control member <NUM> and the resilient member <NUM> can be deemed as a controller. Specifically, the control member <NUM> and the resilient member <NUM> are disposed between the piston <NUM> and the base <NUM>. In the present embodiment, the control member <NUM> and the resilient member <NUM> are two separate parts. Preferably, the control member <NUM> defines a space <NUM>, and the space <NUM> is configured to accommodate the resilient member <NUM>. The control member <NUM> and the resilient member <NUM> are movable between the base <NUM> and the piston <NUM>. Hereinafter, the resilient member <NUM>, for example, is a disc spring, but it is not limited thereto.

The spring <NUM> is configured to provide an elastic force to the piston <NUM>. Hereinafter, the spring <NUM> providing the elastic force to the piston <NUM> through the base <NUM> is illustrative of an example. In other words, the elastic force generated by the spring <NUM> is exerted to the piston <NUM> and the base <NUM>.

As shown in <FIG>, the base <NUM> is connected to the piston <NUM> through an extending portion <NUM>, wherein the control member <NUM> and the resilient member <NUM> are movably mounted to the extending portion <NUM>.

As shown in <FIG>, the piston <NUM> and the housing <NUM> are in a pre-damping state. At this time, the piston <NUM> and the chamber <NUM> between the piston <NUM> and the top portion <NUM> of the housing <NUM> define a first zone R1, and the piston <NUM> and the chamber <NUM> between the piston <NUM> and the bottom portion <NUM> of the housing <NUM> define a second zone R2. The extending member <NUM> is able to partially extend out of the chamber <NUM> of the housing <NUM> rapidly by the elastic force generated by the spring <NUM>. Moreover, the chamber <NUM> of the housing <NUM> is filled with a damping medium. The said damping medium includes a fluid (the damping medium is illustrated as a plurality of black dots in <FIG>). The passages <NUM> of the piston <NUM> and the passages <NUM> of the base <NUM> are configured to allow the damping medium to pass through. The control member <NUM> and the resilient member <NUM> are located between passage openings E1 of the passages <NUM> of the base <NUM> and passage openings E2 of the passages <NUM> of the piston <NUM>.

The inner wall <NUM> of the housing <NUM> has a first inner diameter S1 and a second inner diameter S2 from the top portion <NUM> to the bottom portion <NUM> of the housing <NUM>. Preferably, the inner wall <NUM> further has a third inner diameter S3. In the present embodiment, the inner wall <NUM> of the housing <NUM> has the first inner diameter S1, the second inner diameter S2 and the third inner diameter S3 arranged in order from the top portion <NUM> to the bottom portion <NUM> of the housing <NUM>, wherein the first inner diameter S1 is greater than the second inner diameter S2, and the second inner diameter S2 is greater than the third inner diameter S3. It is noticed that the housing <NUM> has a frontal section <NUM>, a middle section <NUM> and an end section <NUM> in order from the top portion <NUM> to the bottom portion <NUM> of the housing <NUM>. As shown in <FIG>, the inner wall <NUM> has the first inner diameter S1 located corresponding to the frontal section <NUM>, the inner wall <NUM> has the second inner diameter S2 located corresponding to the middle section <NUM>, and the inner wall <NUM> has the third inner diameter S3 located corresponding to the end section <NUM>, respectively. According to the arrangement, the damping device <NUM> is capable of providing a damping effect with a substantially gradual increment along the frontal section <NUM>, the middle section <NUM> and the end section <NUM> of the housing <NUM>. Further, the inner wall <NUM> of the frontal section <NUM> and the inner wall <NUM> of the end section <NUM> are both cylindrical surfaces, and the inner wall <NUM> of the middle section <NUM> is a truncated cone surface. The truncated cone surface (i.e. the inner wall <NUM> of the middle section <NUM>) is connected to both of the cylindrical surfaces (i.e. the inner wall <NUM> of the frontal section <NUM> and the inner wall <NUM> of the end section <NUM>). Thereby, the damping device <NUM> is capable of providing a first constant damping effect in the frontal section <NUM> and a second constant damping effect in the end section <NUM>. Besides, the damping device <NUM> is capable of providing the damping effect with the substantially gradual increment in the middle section <NUM>. Besides, the housing <NUM> has an outer diameter OD, and the outer diameter OD of the housing <NUM> retains a constant value from the top portion <NUM> to the bottom portion <NUM> of the housing <NUM>. That is, the outer diameter OD corresponding to the frontal section <NUM>, the outer diameter OD corresponding to the middle section <NUM> and the outer diameter OD corresponding to the end section <NUM> are equal to one another. The arrangement where the outer diameter OD of the housing <NUM> retains the constant value from the top portion <NUM> to the bottom portion <NUM> of the housing <NUM> ensures the damping device <NUM> not to require an extra externally mechanical space, so that the damping device <NUM> is able to be implemented to the same apparatus (for example, the furniture part) due to no requirement of the extra externally mechanical space.

In addition, the base <NUM> is connected to the second side 24b of the piston <NUM> through the extending portion <NUM>. On the other hand, the control member <NUM> and the resilient member <NUM> are movable between the passages <NUM> of the base <NUM> and the passages <NUM> of the piston <NUM> along the extending portion <NUM>. Besides, the passages <NUM> of the piston <NUM> communicate with the first side 24a and the second side 24b of the piston <NUM>.

As shown in <FIG>, when the piston <NUM> is moved relative to the housing <NUM> by a damping speed, for example, one of the piston <NUM> and the housing <NUM> is displaced relative to the other one of the piston <NUM> and the housing <NUM>, the damping device <NUM> is able to provide a damping effect. The damping effect provided by the damping device <NUM> can be various according to different conditions. In the present embodiment, it is illustrative of an example that the piston <NUM> receiving a force (or an external force) through the extending member <NUM> to move the piston <NUM> relative to the housing <NUM>.

In the first condition, for example, a first force F1 is exerted to the extending member <NUM> or the piston <NUM> and causes the extending member <NUM> or the piston <NUM> to generate a first speed, and the piston <NUM> can pass through the chamber <NUM> defined by the first inner diameter S1, the second inner diameter S2 and the third inner diameter S3 in order (<FIG> only illustrate the piston <NUM> being located in the end section of the interior of the chamber <NUM> defined by the second inner diameter S2). During the process, the damping medium in the second zone R2 (the damping medium is illustrated as a plurality of black dots in <FIG>) flows towards the said first zone R1 in response to the first force F1 and generates a first corresponding force F1'. Specifically, the fluid of the damping medium can flow from a zone of the second side 24b of the piston <NUM> to a zone of the first side 24a of the piston <NUM>, so as to generate the first corresponding force F1'. Hereinafter, the fluid of the damping medium can flow out from the passage openings E1 of the passages <NUM> of the base <NUM>, and then reaches the zone of the first side 24a of the piston <NUM> through the passages <NUM> of the piston <NUM> and a clearance between the peripheral of the piston <NUM> and the inner wall <NUM> of the housing <NUM>, respectively. The control member <NUM> and the resilient member <NUM> can be driven by the first corresponding force F1' and taken away from the passage openings E1 of the base <NUM> to approach the passage openings E2 of the piston <NUM>, so as to control the flow rate of the damping medium from the second side 24b to the first side 24a through the passages <NUM> of the piston <NUM>. In other words, the control member <NUM> is capable of being moved towards the passages <NUM> of the piston <NUM> according to the damping speed. Herein, the resilient member <NUM> generates a resilient force in response to the damping speed. For example, the resilient member <NUM> can be moved to abut against a surface <NUM> of the second side 24b of the piston <NUM>. Thereby, the damping device <NUM> is able to provide a first damping effect in response to the first condition. Herein, the spring <NUM> accumulates an elastic force in response to the displacement of the piston <NUM>. When the elastic force is released, the elastic force is configured to recover the piston <NUM> and the housing <NUM> to the pre-damping state shown in the <FIG>.

As shown in <FIG>, in the second condition, for example, a second force F2 is exerted to the extending member <NUM> or the piston <NUM> and causes the extending member <NUM> or the piston <NUM> to generate a second speed, and the second speed is greater than the first speed. The piston <NUM> can pass through the chamber <NUM> defined by the first inner diameter S1, the second inner diameter S2 and the third inner diameter S3 in order (<FIG> only illustrate the piston <NUM> being located in the chamber <NUM> defined by the third inner diameter S3). At this time, the damping medium (the damping medium is illustrated as a plurality of black dots in <FIG>) generates a second corresponding force F2' in response to the second force F2 and against the second force F2. Specifically, the fluid of the damping medium flows from the zone of the second side 24b of the piston <NUM> to the zone of first side 24a of the piston <NUM> for generating the second corresponding force F2'. Herein, the second corresponding force F2' is able to drive the control member <NUM> and the resilient member <NUM> to depart from the passage openings E1 of the base <NUM> and approach the passage openings E2 of the piston <NUM>. Preferably, the control member <NUM> is located in a predetermined position X adjacent to the second side 24b of the piston <NUM> in response to the second corresponding force F2', such that the control member <NUM> is able to close a portion or all portions of the passages <NUM> of the piston <NUM>, so as to control the flow rate of the damping medium passing through the passages <NUM> of the piston <NUM> to increase the damping force. The resilient member <NUM> is located in the predetermined position X in response to the control member <NUM> and accumulates a resilient force F3. That is, the control member <NUM> can close the portion or the all portions of the passages <NUM> of the piston <NUM> according to the damping speed, so as to control the flow rate of the damping medium passing through the passages <NUM> of the piston <NUM>. For example, when the second corresponding force F2' is exerted to the control member <NUM> which has closed the passages <NUM> of the piston <NUM>, the flow rate of the damping medium passing through the passages <NUM> of the piston <NUM> from the zone of the second side 24b of the piston <NUM> to the zone of the first side 24a of the piston <NUM> will be reduced or cut off. Therefore, when the control member <NUM> closes the passages <NUM> of the piston <NUM> and the fluid of the damping medium flows out from the passage openings E1 of the passages <NUM> of the base <NUM>, the fluid of the damping medium reaches the zone of the first side 24a of the piston <NUM> through the clearance between the peripheral of the piston <NUM> and the inner wall <NUM> of the housing <NUM>, which results in a significant damping force. On the other hand, the resilient member <NUM> deforms elastically due to abutting against the surface <NUM> of the piston <NUM> and accumulates the resilient force F3. Thereby, it is known that the damping device <NUM> can provide a second damping effect according to the second condition.

In a third condition or in a pre-damping condition, when the piston <NUM> is located in the chamber <NUM> defined by the first inner diameter S1, the second inner diameter S2 and the third inner diameter S3 (<FIG> only illustrate the piston <NUM> being located in the chamber <NUM> defined by the third inner diameter S3) and the second force F2 is exerted to the piston <NUM> (in the third condition, the second force F2 is an impulse or a sudden excessive force), similar to the second condition, the control member <NUM> is capable of closing at least the portion or all portions of the passages <NUM> of the piston <NUM> in response to the second corresponding force F2' to increase the damping force, and the resilient member <NUM> accumulates the resilient force F3. As shown in <FIG>, <FIG>, once a speed of the second force F2 exerted to the piston <NUM> or the extending member <NUM> is decreased to a certain degree by the said increased damping force, or the second force F2 decreases less than the resilient force F3 accumulated by the resilient member <NUM>, the resilient member <NUM> will release the resilient force F3 and the resilient force F3 is exerted to the control member <NUM>, such that the control member <NUM> is moved away from the predetermined position X and no longer closes the passages <NUM> of the piston <NUM>. Thereby, the damping device <NUM> provides a weaker damping force in response to the third condition changing from the second damping effect. That is, the damping device <NUM> is able to provide a variable damping effect.

<FIG> are diagrams illustrating a damping device <NUM> according to a second embodiment of the present invention. Specifically, a major difference between the damping device <NUM> according to the second embodiment and the damping device <NUM> according to the first embodiment is that the said spring <NUM> is omitted in the damping device <NUM>. Furthermore, a chamber <NUM> in a housing <NUM> of the damping device <NUM> is filled with a damping medium. The said damping medium includes a fluid (the damping medium is illustrated as a plurality of black dots in <FIG>). The chamber <NUM> is pressurized in advance. When an extending member <NUM> or a piston <NUM> receives a force F4 (or an external force), a control member <NUM> is capable of closing a portion or all portions of passages <NUM> of the piston <NUM>. Once the force F4 stops, a pressure in the chamber <NUM> is able to drive the fluid of the damping medium to gradually activate the piston <NUM>, leading the piston <NUM> and the housing <NUM> to recover to the pre-damping state (as shown in <FIG>).

<FIG> are diagrams illustrating a damping device <NUM> according to a third embodiment of the present invention. Specifically, a major difference between the damping device <NUM> according to the third embodiment and the damping devices <NUM>, <NUM> according to the first and the second embodiment respectively is that a resilient member <NUM> is a flat sheet and a second side <NUM> of a piston <NUM> includes a connecting portion <NUM> and a contacting portion <NUM>. A surface <NUM> of the connecting portion <NUM> and the contacting portion <NUM> are spaced by a step difference H. Furthermore, a base <NUM> is connected to the connecting portion <NUM> of the piston <NUM> through an extending portion <NUM>. On the other hand, a control member <NUM> and the resilient member <NUM> are movable between passages <NUM> of the base <NUM> and passages <NUM> of the piston <NUM> along the extending portion <NUM>. When the extending member <NUM> or the piston <NUM> receives a force F5 (or an external force), in a pre-damping state, the control member <NUM> is capable of abutting against the contacting portion <NUM> of the piston <NUM> in response to a corresponding force K of a fluid of a damping medium, so as to close a portion or all portions of the passages <NUM> of the piston <NUM> for controlling a flow rate of the damping medium passing through the passages <NUM> of the piston <NUM>. Thus, the damping force increases accordingly. The resilient member <NUM> abuts against the surface <NUM> of the connecting portion <NUM> of the piston <NUM> and deforms elastically through the step difference H, so as to accumulate a resilient force. When the force F5 decreases and the resilient member <NUM> releases the resilient force, the control member <NUM> no longer closes the passages <NUM> of the piston <NUM>.

<FIG> are diagrams illustrating a damping device <NUM> not according to the present invention. Specifically, a major difference between the damping device <NUM> and the damping devices <NUM>, <NUM>, <NUM> according to the first, the second and the third embodiment respectively is that a control member <NUM> and a resilient member <NUM> are integrally formed as a part. Moreover, an appearance of a controller formed by the control member <NUM> and the resilient member <NUM> is a disc spring. A concave portion <NUM> is defined between the resilient member <NUM> and the control member <NUM>. When an extending member <NUM> or a piston <NUM> receives a force F6 (or an external force), in a pre-damping condition, the control member <NUM> is capable of abutting against a contacting portion <NUM> of the piston <NUM> in response to a corresponding force K of a fluid of a damping medium, so as to close a portion or all portions of passages <NUM> of the piston <NUM> for controlling a flow rate of the damping medium passing through the passages <NUM> of the piston <NUM>. Thus, a damping force increases accordingly. The resilient member <NUM> abuts against a surface <NUM> of a connecting portion of the piston <NUM>, so as to provide a resilient force. When the force F6 decreases and the resilient member <NUM> releases the resilient force, the control member <NUM> no longer closes the passages <NUM> of the piston <NUM>. It is noticed that the concave portion <NUM> facilitates the corresponding force K of the fluid of the damping medium to drive the control member <NUM> for closing the passages <NUM> of the piston <NUM>.

<FIG> are diagrams illustrating a damping device <NUM> not according the present invention. Specifically, a major difference between the damping device <NUM> and the damping device <NUM> is that no concave portion <NUM> is defined between the resilient member <NUM> and the control member <NUM>. Specifically, a side <NUM> of a control member <NUM> is a plane. Therefore, when an extending member <NUM> or a piston <NUM> receives a force F7 (or an external force), in a pre-damping condition, the control member <NUM> is capable of receiving a corresponding force K of a fluid of a damping medium through the side <NUM>, so as to close a portion or all portions of passages <NUM> of the piston <NUM>. Namely, this embodiment is able to provide the functions mentioned above.

<FIG> is a diagram illustrating a damping device <NUM> according to a fourth embodiment of the present invention.

Specifically, a major difference between the damping device <NUM> according to the fourth embodiment and the damping devices according to the first to the third embodiments is that an inner wall <NUM> of a housing <NUM> has a first inner diameter S4, a second inner diameter S5 and a third inner diameter S6 arranged in order from a top portion <NUM> to a bottom portion <NUM> of the housing <NUM>, wherein the first inner diameter S4 is greater than the second inner diameter S5, and the third inner diameter S6 is greater than the second inner diameter S5. It is noticed that the housing <NUM> has a frontal section <NUM>, a middle section <NUM> and an end section <NUM> in order from the top portion <NUM> to the bottom portion <NUM> of the housing <NUM>. As shown in <FIG>, the inner wall <NUM> has the first inner diameter S4 located corresponding to the frontal section <NUM>, the inner wall <NUM> has the second inner diameter S5 located corresponding to the middle section <NUM>, and the inner wall <NUM> has the third inner diameter S6 located corresponding to the end section <NUM>, respectively. According to the arrangement, the damping device <NUM> is capable of providing a non-gradual damping effect along the frontal section <NUM>, the middle section <NUM> and the end section <NUM> of the housing <NUM> substantially. Further, the inner wall <NUM> of the frontal section <NUM>, the inner wall <NUM> of the middle section <NUM> and the inner wall <NUM> of the end section <NUM> are connected to one another to form a camber. A vertex of the camber is located on the inner wall <NUM> of the middle section <NUM>, and the second inner diameter S5 of the inner wall <NUM> of the middle section <NUM> is a distance between two opposite vertices on a cross-section of the inner wall <NUM> of the middle section <NUM>. Besides, the housing <NUM> has an outer diameter OD, and the outer diameter OD of the housing <NUM> retains a constant value from the top portion <NUM> to the bottom portion <NUM> of the housing <NUM>. That is, the outer diameter OD corresponding to the frontal section <NUM>, the outer diameter OD corresponding to the middle section <NUM> and the outer diameter OD corresponding to the end section <NUM> are equal to one another. The arrangement where the outer diameter OD of the housing <NUM> retains the constant value from the top portion <NUM> to the bottom portion <NUM> of the housing <NUM> ensures the damping device <NUM> not to require an extra externally mechanical space, so that the damping device <NUM> is able to be implemented to the same apparatus (for example, the furniture part) due to no requirement of the extra externally mechanical space.

As shown in <FIG>, the said damping devices according to each of the embodiments can be implemented in a furniture part <NUM>. Hereinafter, the damping device <NUM> implemented in the furniture part <NUM> is illustrative of an example. Specifically, the furniture part <NUM> includes a first furniture member <NUM>, a second furniture member <NUM> and a driving mechanism. The first furniture member <NUM>, for example, is a first rail (a stationery rail) fixed to a cabinet body 60a. On the other hand, the second furniture member <NUM>, for example, is a second rail (a sliding rail) movable relative to the first rail, and the second furniture member <NUM> is configured to mount a drawer 62a. The driving mechanism includes an ejection device <NUM> and a retraction device <NUM>, wherein the second furniture member <NUM> (the drawer 62a) is located in a first position P1 (for example, a closed position) relative to the first furniture member <NUM> (the cabinet body 60a).

Referring to <FIG>, <FIG> and <FIG>, when the second furniture member <NUM> is pressed by a user and displaced from the first position P1 to a second position P2 (for example, an over-pressed position shown in <FIG>) in a first direction D1 relative to the first furniture member <NUM> and the user releases the pressing force, the ejection device <NUM> including an opening spring will provide an opening force, so that the second furniture member <NUM> is moved, in response to the opening force, to a third position P3 (for example, an open position shown in <FIG>) in a second direction D2 opposite to the first direction D1. That is a so-called self-opening function. During a final step where the second furniture member <NUM> is pushed by the user to be moved from the third position P3 to approach the first position P1 in the first direction D1 relative to the first furniture member <NUM>, the retraction device <NUM> including a closing spring provides a closing force, so that the second furniture member <NUM> is moved to the first position P1. That is a so-called self-closing function. Since the self-opening function and the self-closing function are well-known by one of ordinary skill in the art, the detailed description is omitted herein for simplicity. On the other hand, by a relative motion between the piston <NUM> (or the extending member <NUM>) and the housing <NUM> of the damping device <NUM> is able to provide a damping effect to the second furniture member <NUM> during a process where the second furniture member <NUM> is moved toward the first position P1 in response to the closing force.

A curve diagram of the damping force according to the first condition is shown in <FIG>, wherein the vertical axis represents a force in Newton (N), and the horizontal axis represents a distance in millimeter (mm).

For example, when the second furniture member <NUM> is moved from the third position P3 toward the first position P1 in the first direction D1 using the damping device <NUM> for providing the damping force, according to the said first condition (this part can be referred to <FIG>), the fluid of the damping medium can flow out from the passage openings E1 of the passages <NUM> of the base <NUM>, and reach the zone of the first side 24a of the piston <NUM> through the passages <NUM> of the piston <NUM>. Therefore, during a process where the damping force D reaches a main damping zone B2 from a pre-damping zone B1 (as the said pre-damping state) which is in front of the first position P1, the damping force D is able to substantially retain the same in response to the first force F1 (for example, the closing force of the retraction device <NUM>) exerted to the second furniture member <NUM>. In other words, the damping device <NUM> can provide the first damping effect before the second furniture member <NUM> reaches the first position P1, so as to decrease a velocity of the second furniture member <NUM> before reaching the first position P1. Besides, an over-pressed zone B3 is defined between the first position P1 and the second position P2.

Otherwise, when the second furniture member <NUM> is moved from the third position P3 toward the first position P1 in the first direction D1 and the damping force D is provided by the damping device <NUM>, according to the said second condition (this part can be referred to <FIG>), the control member <NUM> is capable of closing the portion or the all portions of the passages <NUM> of the piston <NUM>, so as to control the flow rate of the damping medium passing through the passages <NUM> of the piston <NUM> from the zone of the second side 24b to the zone of the first side 24a of the piston <NUM>. Therefore, as shown in <FIG>, during the process where the damping force D reaches the main damping zone B2 from the pre-damping zone B1 in front of the first position P1, the damping force D will rise greatly in response to the second force F2 (for example, a continual excessive force exerted by the user to the second furniture member <NUM>). In other words, the damping device <NUM> can provide the second damping effect before the second furniture member <NUM> reaches the first position P1, so as to rapidly decelerate the second furniture member <NUM>. At this time, when the control member <NUM> closes the passages <NUM> of the piston <NUM>, the control member <NUM> substantially prevents the second furniture member <NUM> from being moved relative to the first furniture member <NUM> from the first position P1 to the second position P2 so as to prevent the second furniture member <NUM> (the drawer 62a) from being moved relative to the first furniture member <NUM> (the cabinet body 60a) to the second position P2 and resulting in an unintentional activation (without intention), which provides the opening force, of the ejection device <NUM>.

Otherwise, when the second furniture member <NUM> is moved from the third position P3 toward the first position P1 in the first direction D1 and the damping force is provided by the damping device <NUM>, according to the said third condition (this part can be referred to <FIG>), the control member <NUM> is capable of closing the portion or the all portions of the passages <NUM> of the piston <NUM>, so as to control the flow rate of the damping medium passing through the passages <NUM> of the piston <NUM> from the zone of the second side 24b of the piston <NUM> to the zone of the first side 24a. Besides, when the second force F2 exerted to the second furniture <NUM> (for example, an instant excessive force exerted to the second furniture member <NUM> by the user) decreases to a certain degree, the resilient member <NUM> releases the resilient force to the control member <NUM>, and the control member <NUM> departs from the predetermined position X and no longer closes the passages <NUM> of the piston <NUM>. Therefore, the second damping effect is switched to the third damping effect with the weaker damping force D. Accordingly, as shown in <FIG>, during the process where the damping force D reaches the main damping zone B2 from the pre-damping zone B1 in front of the first position P1, the damping force D will rise greatly in response to the second force, and the damping force D decreases rapidly before the second furniture member <NUM> reaches the first position P1.

Thereby, the damping device <NUM> is capable of providing damping effects with different degree according to various external forces. When an instant pushing force toward the first direction D1, exerted by the user during the process where the second furniture member <NUM> is moved from the third position P3 relative to the first furniture member <NUM>, is excessive, by the second or the third damping effect provided by the damping device <NUM> will decrease the force exerted to the second furniture member <NUM> (the drawer 62a) rapidly, so as to prevent the second furniture member <NUM> (the drawer 62a) from directly passing the first position P1 to the second position P2 from the third position P3 relative to the first furniture member <NUM> (the cabinet body 60a). It prevents the ejection device <NUM> providing an opening force from an unintentional activation (without intention). That is, during the final step where the second furniture member <NUM> is moved from the third position P3 to the first position P1, it effectively ensures that the second furniture member <NUM> is stopped in the first position P1 by the damping device <NUM>, so as to enhance the stability and reliability of the driving mechanism.

Claim 1:
A damping device (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), comprising:
a housing (<NUM>, <NUM>, <NUM>) having an inner wall (<NUM>, <NUM>), a chamber (<NUM>, <NUM>) being defined by the inner wall (<NUM>, <NUM>) and having a damping medium filled therewith, wherein the inner wall (<NUM>, <NUM>) has a first inner diameter (S1, S4), a second inner diameter (S2, S5) and a third inner diameter (S3, S6), the first inner diameter (S1, S4) is different from the second inner diameter (S2, S5), the second inner diameter (S2, S5) is different from the third inner diameter (S3, S6); and
a piston (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) movable in the chamber (<NUM>, <NUM>) along a substantially linear direction, the piston (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising a passage (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) configured to allow the damping medium to pass through;
a base (<NUM>, <NUM>) connected to the piston (<NUM>, <NUM>) through an extending portion (<NUM>, <NUM>), the base (<NUM>, <NUM>) comprising a passage (<NUM>, <NUM>) for allowing the damping medium to pass through;
a spring (<NUM>) configured to provide an elastic force to one of the piston (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and the base (<NUM>, <NUM>); and
a controller disposed between the passage (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) of the piston (<NUM>, <NUM>) and the passage (<NUM>, <NUM>) of the base (<NUM>, <NUM>), the controller being movably mounted to the extending portion (<NUM>, <NUM>), the controller comprising a control member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and a resilient member (<NUM>, <NUM>, <NUM>), the control member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and the resilient member (<NUM>, <NUM>, <NUM>) being disposed between the piston (<NUM>, <NUM>) and the base (<NUM>, <NUM>), wherein a space (<NUM>) is defined by the control member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), the space (<NUM>) is configured to accommodate the resilient member (<NUM>, <NUM>, <NUM>), wherein the control member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is capable of closing a portion or all portions of the passage (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) of the piston (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein the resilient member (<NUM>, <NUM>, <NUM>) is configured to provide a resilient force (F3) for the control member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to no longer close the passage (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) of the piston (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>).