Patent Description:
The stroller is a very common baby product for parents to safely and steadily carry their baby on indoor and outdoor roads and provide care to the baby at the same time. Generally, a stroller includes a seat for an infant or a kid to sit thereon and a stroller frame for carrying the seat, and is designed to be lockable and foldable, such that when the stroller is in use, the seat and the stroller frame are locked in a unfolded state, and the seat and the stroller frame are both folded to reduce the occupied space when the use is done. However, currently, in the most strollers, a seat and a stroller are locked and unlocked through different locking mechanisms, and users need to operate each of the locking mechanisms to unlock the seat and the stroller frame, which is inconvenient to users. In addition, the multiple locking mechanisms in a stroller are complicated and easily damaged. <CIT> discloses an infant stroller apparatus that includes a first and a second leg segment, a handle segment and a backrest frame. The first and second leg segments are respectively affixed with a first and a second coupling member that are connected with each other. The handle segment is affixed with a third coupling member that is connected with the first coupling member. The backrest frame is connected with the second leg segment. A latch assembled with the second coupling member is movable to engage with the third coupling member to lock the handle segment and the first and second leg segments in an unfolded state. A release actuator operatively connected with the latch is pivotally connected with the second leg segment adjacent to the pivot axis of the backrest frame. The release actuator is rotatable to cause the latch to disengage from the third coupling member for allowing folding of the infant stroller apparatus. <CIT> and <CIT> also disclose collapsible strollers.

The present invention discloses a stroller having a synchronous unlocking mechanism, which can synchronously unlock locking states of a seat and a stroller frame, thereby saving the user's unlocking steps and time and simplifying the mechanism.

The present invention provides a stroller comprising a seat, a stroller frame and a synchronous unlocking mechanism, configured on the seat and the stroller frame, in which the seat includes a seat frame, a backrest and a shaft, the seat frame is pivotally connected to the backrest through the shaft, and the stroller frame includes a fixing member for selectively locking the stroller frame. The synchronous unlocking mechanism includes a grip, a locking member, an elastic member and a towing member, wherein the grip is pivotally connected to the seat frame and/or the backrest; the locking member is slidably disposed on the shaft, the seat frame and the backrest along an axial direction of the shaft and is coupled to the grip; the elastic member is configured between the locking member and the seat frame or between the locking member and the backrest; and the towing member is connected to the grip and the fixing member.

In one embodiment, the locking member comprises a main body and an extending arm, wherein the main body is configured between the seat frame and the backrest, and the extending arm is connected to the main body and passes through the grip and the seat frame along the axial direction. The grip is formed with a through hole, at least one abutting portion is formed on the through hole, the abutting portion comprises a driving surface, the extending arm comprises a driven surface, and the driving surface and the driven surface are inclined with respect to the axial direction and abut against each other.

In one embodiment, there are multiple extending arms, these extending arms are symmetrically arranged with respect to the main body, and a protrusion is formed on one end of each of the plurality of extending arms away from the main body.

In one embodiment, the synchronous unlocking mechanism further comprises an operating member, a driving member, an abutting member and a connecting member, wherein the operating member is configured on the backrest, the driving member and the abutting member are slidably disposed on the backrest along a radial direction of the shaft, and the connecting member is connected to the operating member and the driving member.

In one embodiment, the driving member comprises a driving surface, the abutting member comprises a driven surface, and the driving surface of the driving member and the driven surface of the abutting member are inclined with respect to the axial direction and abut against each other.

In one embodiment, the grip comprises a guiding rail and a slider, a distance between the guiding rail and the shaft is in a gradational relationship, the slider is slidably disposed on the guiding rail, and the towing member is connected to the grip through the slider.

In one embodiment, the seat is configured on the stroller frame.

In one embodiment, the stroller frame further comprises a handle, a joint, a front leg and a rear leg. One end of the handle is pivotally connected to the rear leg and is hanged with the front leg through the joint, at least one part of the fixing member is configured in the joint, and a pivotal connection of the handle and the rear leg is located above the joint.

In one embodiment, the stroller frame further comprises a link, the link is pivotally connected to the front leg and the rear leg, and a pivotal connection between the front leg and the link is located below the joint.

In one embodiment, the stroller frame further comprises a supporting member, the supporting member is configured on the link, and the seat frame is slidably disposed on the supporting member.

In one embodiment, the backrest comprises a stud, one end of the rear leg is formed with a groove thereon, and the stub is configured in the groove.

In one embodiment, the seat frame is formed with a recess, and at least one part of the grip is accommodated in the recess.

In one embodiment, the seat frame comprises a restricting portion, and the restricting portion is configured in the recess and selectively abuts against the grip.

In one embodiment, the seat frame and the backrest respectively comprise a locking portion, and the locking portion and the locking member match each other.

In one embodiment, the seat frame is formed with a wire-aligning portion, the wire-aligning portion is configured at an outer side of the guiding rail with respect to the shaft, and the towing member passes through the wire-aligning portion.

Therefore, in the synchronous unlocking mechanism and the stroller of the present invention, the locking member is driven by the grip so as to slide between the seat frame and the backrest, thereby locking or unlocking the seat and the backrest, and the fixing member is driven by the grip through the towing member so as to synchronously unlock the stroller frame. Accordingly, the present invention saves the user's time to unlock different components of the stroller, and also simplify the mechanism to reduce the probability of failure of the stroller.

In order to make the above-mentioned features and advantages of the present invention easier to understand, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

The foregoing and other technical content, features, and effects of the present invention will be clearly presented in the following detailed description of the preferred embodiment with reference to the drawings. The terms indicating directions in the following embodiments, for example: up, down, left, right, front or back, etc., only refer to the directions in the accompanying drawings. Therefore, the terms indicating directions are used for illustration, not for limiting the present invention. Further, in the following embodiments, the same or similar elements will be denoted by the same or similar reference numerals.

Please refer to <FIG>. <FIG> is a perspective schematic view of an unfolded state of a stroller according to an embodiment of the present invention. <FIG> is a perspective schematic view of the stroller of <FIG> from another angle. <FIG> is a perspective schematic view of the stroller of <FIG> from another angle. <FIG> is an enlarged schematic diagram of an area A in <FIG>. <FIG> is an enlarged schematic diagram of an area B in <FIG>. In this embodiment, a stroller <NUM> includes a seat <NUM>, a stroller frame <NUM> and a synchronous unlocking mechanism <NUM>, wherein the seat <NUM> is used for an infant or a toddler to sit thereon and includes a seat frame <NUM>, a backrest <NUM> and a shaft <NUM>, the seat frame <NUM> and the backrest <NUM> are connected to each other through the shaft <NUM>, the seat <NUM> is configured on the stroller frame <NUM>, and the synchronous unlocking mechanism <NUM> is connected to the seat <NUM> and the stroller frame <NUM>. Please note that the x-direction, y-direction, and z-direction in <FIG> respectively represent the front, left, and upper sides of the stroller frame <NUM>, and will be used in the following descriptions.

In detail, the shaft <NUM> penetrates the left and right ends of the seat frame <NUM> and the backrest <NUM>, such that the left end of the backrest <NUM> is pivotally connected to the left side of the seat frame <NUM>, and the right end of the backrest <NUM> is pivotally connected to the right side of the seat frame <NUM>, thereby increasing the connection strength when the seat frame <NUM> and the backrest <NUM> pivot to each other. On the other hand, the stroller frame <NUM> includes a left front leg 20a, a right front leg 20b, a left rear leg 20c, a right rear leg 20d, a left joint 20e, a right joint 20f and a handle <NUM>. The left and right ends of the handle <NUM> are pivotally connected to the left rear leg 20c and the right rear leg 20d, respectively, and are hinged with the left front leg 20a and the right front leg 20b through the left joint 20e and the right joint 20f, respectively. As shown in the figures, the pivotal connection of the handle <NUM> and the left rear leg 20c is disposed above the left joint 20e, and the pivotal connection of the handle <NUM> and the right rear leg 20d is disposed above the right joint 20f, so as to facilitate the pivoting of the handle <NUM> relative to the left front leg 20a, the right front leg 20b, the left rear leg 20c and the right rear leg 20d, which will be described in detail later. In addition, the stroller frame <NUM> has a substantially symmetrical structure, and thus only the components on one side of the stroller frame <NUM> will be described as a representative in the following descriptions.

Please refer to <FIG>. <FIG> is a perspective schematic view showing the assembly of the seat and the synchronous unlocking mechanism of <FIG>. <FIG> is a perspective schematic view showing the assembly of <FIG> from another angle. <FIG> is an exploded schematic diagram showing some components of <FIG>. <FIG> is an enlarged schematic diagram showing the driving member and the abutting member in <FIG>. <FIG> is an enlarged schematic diagram of an area C in <FIG>. <FIG> is a perspective schematic view showing some components of the seat frame, which are not shown in <FIG>. <FIG> is an enlarged schematic diagram of an area D in <FIG>. <FIG> is a perspective schematic view showing the components of <FIG> from another angle. <FIG> is an enlarged schematic diagram of an area E in <FIG>. In the present embodiment, the synchronous unlocking mechanism <NUM> is used for synchronously unlocking the backrest <NUM> and the stroller frame <NUM>, and includes a grip <NUM>, a locking member <NUM>, an elastic member <NUM> and a towing member <NUM>. The grip <NUM> is pivotally connected to the seat frame <NUM> along an axis L, and the grip <NUM>, the seat frame <NUM> and the backrest <NUM> are stacked in sequence. Preferably, the axis L is parallel to the left and right directions of the stroller frame <NUM>. More preferably, the axis L passes through the shaft <NUM> and coincides with the axis of the shaft <NUM>, so as to reduce the extra load caused by the eccentric rotation of the handle <NUM> , the seat frame <NUM> and the backrest <NUM> with each other. Certainly, according to actual needs, the grip <NUM> can also be pivotally connected to the backrest <NUM> and configured between the seat frame <NUM> and the backrest <NUM>, or disposed at an outer side of the seat frame <NUM>, which also achieves the purpose of pivoting the handle <NUM>, the seat frame <NUM> and the backrest <NUM>, and the present invention is not limited thereto.

On the other hand, the locking member <NUM> is sleeved on the shaft <NUM> and slidably disposed on the shaft <NUM>, the seat frame <NUM> and the backrest <NUM> along the axial direction of the shaft <NUM>. Therefore, the locking member <NUM> can slide between a locking position (as shown in <FIG>) and an unlocking position. When the locking member <NUM> is disposed at the locking position, the seat frame <NUM> and the backrest <NUM> are in the locking state and cannot pivot relatively to each other. When the locking member <NUM> is disposed at the unlocking position, the seat frame <NUM> and the backrest <NUM> can pivot relatively to each other. In addition, the locking member <NUM> is coupled to the grip <NUM>, such that when the grip <NUM> rotates relatively to the axis L, the locking member <NUM> switches between the aforementioned locking position and the unlocking position.

In this embodiment, the elastic member <NUM> is, for example, a spring, and is configured between the locking member <NUM> and the seat frame <NUM>, such that when the user does not operate the synchronous unlocking mechanism <NUM>, the locking member <NUM> is pushed by the elastic member <NUM> and maintained in the locking position, so as to avoid an accidental folding of the stroller <NUM> during use. In other embodiment, the elastic member <NUM> can be configured between the locking member <NUM> and the backrest <NUM>, and the locking member <NUM> can be pulled to the locking position by stretching tension, which is not limited in the present invention.

On the other hand, the stroller frame <NUM> further includes at least one fixing member <NUM> (referring to <FIG>). In the present embodiment, there are two fixing members <NUM>, which are respectively accommodated in the left front leg 20a and the right front leg 20b, and at least one part of the fixing members is configured in the left joint 20a and the right joint 20b for locking the stroller frame <NUM>, such that the handle <NUM> cannot pivot relatively to the left front leg 20a and the right front leg 20b. In other embodiments, there is only one fixing member <NUM>, which is configured at one side of the stroller frame <NUM>, so as to lock the pivoting of the stroller frame <NUM>. The towing member <NUM> is, for example, a cable, for being connected to the grip <NUM> and the fixing member <NUM>. Therefore, when the user operates the grip <NUM> to pivot, the locking member <NUM> slides from the locking position to the unlocking position and release the locking state between the seat frame <NUM> and the backrest <NUM>, and at the same time the grip <NUM> drives the fixing member <NUM> through the towing member <NUM> to unlock the stroller frame <NUM> synchronously, such that the handle <NUM> can pivot relatively to the left front leg 20a and the right front leg 20b, so as to achieve the effect of synchronous unlocking.

Specifically, please refer to <FIG>, <FIG>, <FIG> and <FIG>, in which <FIG> is a perspective schematic view showing the grip of <FIG>, and <FIG> is a perspective schematic view showing the locking member of <FIG>. As shown in <FIG> and <FIG>, the grip <NUM> includes a guiding rail 31b and a slider 31c, wherein the guiding rail 31b is arc-shaped and takes the axis of the shaft <NUM> (that is, the axis L) as the axis, the distance between the guiding rail 31b and the shaft <NUM> and the axis L is in a gradational relationship, the slider 31c is slidably disposed on the guiding rail 31b, and one end of the towing member <NUM> is connected to the slider 31c. In other words, the towing member <NUM> is connected to the grip <NUM> through the slider 31c. With this configuration, when the user rotates the grip <NUM>, the slider <NUM> c is blocked by the seat frame <NUM> and slides with respect to the guiding rail 31b, and since the distance between the guiding rail 31b and the shaft <NUM> is in a gradational relationship, the sliding block <NUM> c changes the relative distance with the fixing member <NUM> as if by the action of a cam, such that the towing member <NUM> drives the fixing member <NUM> and unlocks the stroller frame <NUM>.

The following descriptions illustrate how the grip <NUM> drives the locking member <NUM> to slide from the locking position to the unlocking position. As shown in <FIG>, the grip <NUM> is formed with a through hole 31d, and at least one abutting portion 31e is formed on the through hole 31d. For example, in the present embodiment, there are two abutting portions 31e, which are symmetrically arranged along the circumferential direction of the through hole 31d and protrude toward the inside of the through hole 31d, and each of the abutting portions 31e includes a driving surface 31a for driving the locking member <NUM>. On the other hand, the locking member <NUM> includes a main body 32a and at least one extending arm 32b, in which the main body 32a is configured between the seat frame <NUM> and the backrest <NUM>, and the extending arm 32b is connected to the main body 32a and penetrates the through hole 31d of the grip <NUM> and the seat frame <NUM> along the axial direction of the shaft <NUM>. In addition, the extending arm 32b includes a driven surface <NUM>, and the driving surface 31a and the driven surface <NUM> are inclined with respect to the axial direction and abut against each other. With this configuration, when the grip <NUM> pivots, the driving surface 31a pushes against the driven surface <NUM> along the circumference of the through hole 31d, and since the driving surface 31a and the driven surface <NUM> are both inclined with respect to the axial direction, the locking member <NUM> slides from the locking position to the unlocking position because the extending arm 32b moves toward the inner side of the grip <NUM> along the axial direction.

Furthermore, in order to reduce the bending moment of the single extending arm 32b in the circumferential direction of the through hole <NUM> Id, the number of extending arms 32b may be two, three or even more. These extending arms 32b are arranged symmetrically with respect to the main body 32a, but they can also be arranged asymmetrically. In order to avoid interference between the extending arms 32b, one end of each of the extending arms 32b is formed with a protrusion <NUM> thereon away from the main body 32a, and the driven surface <NUM> is configured on the protrusion <NUM>. At the same time, the grip <NUM> is formed with concaved portions 31f between these abutting portions 31e, and these concaved portions 31f are recessed relatively to the abutting portions 31e in the circumferential direction of the through hole 31d and are used for the extending arm 32b to pass through. With this configuration, the torque of the grip <NUM> pushing the locking member <NUM> can be shared by the extending arms 32b, and the extending arms 32b do not interfere with each other, thereby reducing the volume occupied by the grip <NUM> and the locking member <NUM>.

On the other hand, as shown in <FIG> and <FIG>, the seat frame <NUM> and the backrest <NUM> respectively include a locking portion 12a, and the locking portion 12a and the main body 32a of the locking member <NUM> match each other. In the present embodiment, the main body 32a is an external gear, and the locking portion 12a is an internal gear structure, thereby limiting the rotation stroke between the locking member <NUM> and the seat frame <NUM> and the backrest <NUM> and preventing relative sliding in the circumferential direction. In addition, in order to facilitate the wiring of the towing member <NUM>, as shown in <FIG>, the seat frame <NUM> is formed with a wire-aligning portion 11e, wherein the wire-aligning portion 11e is, for example, a wire groove and is disposed on the outside of the guiding rail 31b with respect to the shaft <NUM>, and the towing member <NUM> passes through the wire-aligning portion 11e. Preferably, the wire-aligning portion 11e is configured at the bottom side of the seat frame <NUM>, so as to prevent the towing member <NUM> from protruding relatively to the upper surface of the seat <NUM> and affecting the riding experience.

In addition to unlocking the seat frame <NUM> and the backrest <NUM> through the grip <NUM>, the synchronous unlocking mechanism <NUM> of the present embodiment also has other ways for unlocking. Please refer to <FIG>, <FIG> and <FIG>, wherein <FIG> is a perspective schematic view showing some components of the backrest, which are not shown in <FIG>, <FIG> is an enlarged schematic diagram of an area F in <FIG>, and <FIG> is a perspective schematic view showing the components of <FIG> from another angle. As shown in the figures, in the present embodiment, the synchronous unlocking mechanism <NUM> further comprises an operating member <NUM>, a connecting member <NUM>, a driving member <NUM> and an abutting member <NUM>, wherein the operating member <NUM> is configured on the backrest <NUM>, the driving member <NUM> and the abutting member <NUM> are slidably disposed on the backrest <NUM> along a radial direction of the shaft <NUM>, and the connecting member <NUM> is connected to the operating member <NUM> and the driving member <NUM>.

In detail, the operating member <NUM> is, for example, a button, which can be operated by the user to unlock the seat frame <NUM> and the backrest <NUM>. The connecting member <NUM> is, for example, a cable, which passes through the inside of the backrest <NUM>, and has one end connected to the operating member <NUM> and the other end connected to the driving member <NUM>. As shown in <FIG> and <FIG>, the driving member <NUM> and the abutting member <NUM> are configured at the outer side of the backrest <NUM>, wherein the driving member <NUM> includes a driving surface <NUM>, the abutting member <NUM> is adjacent to the main body 32a and includes a driven surface <NUM>, and the driving surface <NUM> and the driven surface <NUM> are inclined with respect to the axial direction of the shaft <NUM> and abut against each other. Similar to the situation of the grip <NUM> and the locking member <NUM>, when the user presses or flicks the operating member <NUM>, the operating member <NUM> pulls the driving member <NUM> through the connecting member <NUM> to slide along the radial direction of the shaft <NUM>, and the driving surface <NUM> and the driven surface <NUM> are inclined with respect to the axial direction of the shaft <NUM>, so as to drive the abutting member <NUM> to move along the axial direction of the shaft <NUM> and push the main body 32a to move, such that the locking member <NUM> moves to the unlocking position from the locking position. In other words, when the user wants to unlock the seat frame <NUM> and the backrest <NUM> separately and maintain the deploy of the stroller frame <NUM>, the locking member <NUM> can be unlocked through the operating member <NUM>, which increases the flexibility of using the synchronous unlocking mechanism <NUM>.

Furthermore, the driving member <NUM> is formed with a concaved portion <NUM>, and the abutting member <NUM> is also formed with a concaved portion <NUM>. Therefore, when the driving member <NUM> and the abutting member <NUM> are assembled on the backrest <NUM>, the shaft <NUM> can pass through the inside of the concaved portion <NUM> and the concaved portion <NUM>, thereby limiting the driving member <NUM> and the abutting member <NUM> to a limited extent.

Please refer to <FIG>. As shown in the figures, the seat frame <NUM> is formed with a recess. Preferably, the recess 11a is configured at the back side of the seat frame <NUM>, and at least one part of the grip <NUM> is accommodated in the recess 11a. Specifically, when the user does not operate the synchronous unlocking mechanism <NUM>, the grip <NUM> can be rotated with respect to the axis L and is completely accommodated in the recess 11a, and since the recess 11a is configured at the back side of the backrest <NUM>, it will not affect the infant or toddler who is sitting in the seat. Preferably, the seat frame <NUM> further includes a restricting portion 11b, wherein the restricting portion 11b is, for example, a block, and configured in the recess 11a. When the grip <NUM> is completely accommodated in the recess 11a, the restricting portion 11b can block the grip <NUM> to prevent the grip <NUM> from continuously rotating toward the bottom side of the seat frame <NUM>. In other words, the restricting portion 11b selectively abuts against the grip <NUM>, which makes it more convenient for the user to grab the grip <NUM>.

Please refer to <FIG>. In addition to the above components, the stroller <NUM> of the present embodiment further includes a left link 20j and a right link <NUM>. Taking the left link 20j as an example, one end of the left link 20j is pivotally connected to the left front leg 20a, the other end of the left link 20j is pivotally connected to the left rear leg 20c, and the pivotal connection of the left front leg 20a and the left link 20j is disposed below the left joint 20e. In combination with the pivotal connection of the handle <NUM> and the left rear leg 20c being above the left joint 20e, when the user operates the synchronous unlocking mechanism <NUM> to unlock the fixing member <NUM>, the handle <NUM> and the left front leg 20a are respectively disposed at different sides of the left joint 20e, and since the pivotal connection of the handle <NUM> and the left rear leg 20c is disposed above the left joint 20e, the handle <NUM> can be bent downward when the wheels of the left front leg 20a and the left rear leg 20c are in contact with the ground, that is, the center of gravity of the stroller frame <NUM> is lowered to ensure the stability of the stroller <NUM> when folded.

In detail, as shown in <FIG>, the stroller frame <NUM> further includes a supporting member <NUM>, a first crossing member <NUM> and a second crossing member 20i, wherein the supporting member <NUM> is configured on the left link 20j and the right link <NUM>, and the seat frame <NUM> is slidably disposed on the supporting member <NUM>. Further, the seat frame further includes at least one sleeve l id, which is sleeved on the supporting member <NUM>. Therefore, when the user adjusts angle of the backrest <NUM> through the operating member <NUM>, the seat frame <NUM> can slide in the front and rear directions with respect to the stroller frame <NUM>, such that the center of gravity of the seat <NUM> is located on the back side of the seat frame <NUM> when the infant or toddler is seated, and the center of gravity of the seat <NUM> is moved to the front side of the seat frame <NUM> as the seat frame <NUM> and the backrest pivot forward when folded , which is able to prevent the seat <NUM> carrying the infant or toddler from turning over due to displacement of the center of gravity of the stroller <NUM>.

In addition, the stroller frame further includes a first crossing member <NUM> and a second crossing member 20i. As shown in <FIG> and <FIG> to <FIG>, one end of the first crossing member <NUM> is pivotally connected to the right joint 20f through a right pivoting bracket 20n, the other end of the first crossing member <NUM> is hinged with a second hinge joint 20q through a first hinge joint 20p, and the side of the second hinge joint 20q away from the first hinge joint 20p is pivotally connected to the left link 20j. Similarly, one end of the second crossing member 20i is pivotally connected to the left joint 20e through a left pivoting bracket 20r, the other end of the second crossing member 20i is hinged with a fourth hinge joint 20t through a third hinge joint <NUM>, and the side of the fourth hinge joint 20t away from the third hinge joint <NUM> is pivotally connected to the right link <NUM>. On the other hand, the left link 20j is pivotally connected to the left rear leg 20c through a first hinge joint 20p' and a second hinge joint 20q', and the right link <NUM> is pivotally connected to the right rear leg 20d through a third hinge joint <NUM>' and a fourth hinge joint 20t'. With this configuration, a pivoting centric line L1 between the left rear leg 20c and the handle <NUM>, a pivoting centric line L2 between the right rear leg 20d and the handle, a pivoting centric line L3 between the right pivoting bracket and the right joint 20f, a pivoting centric line L5 between the first hinge joint 20p and the second hinge joint 20q, a pivoting centric line L8 between the left pivoting bracket 20r and the left joint 20e, a pivoting centric line L10 between the third hinge joint <NUM> and the fourth hinge joint 20t, a pivoting centric line L13 between the first hinge joint 20p' and the second hinge joint 20q', a pivoting centric line L16 between the third hinge joint <NUM>' and the fourth hinge joint 20t', a pivoting centric line L19 between the left link 20j and the left front leg 20a and a pivoting centric line L20 between the right link <NUM> and the right front leg 20b all extend along the left and right directions of the stroller frame <NUM>. The pivoting centric line L4 between the right pivoting bracket 20n and the first crossing member <NUM> intersects the pivoting centric line L3, the pivoting centric line L6 between the first hinge joint 20p and the first crossing member <NUM> intersects the pivoting centric line L5, the pivoting centric line L7 between the second hinge joint 20q and the left link 20j interests the pivoting centric line L5, the pivoting centric line L9 between the left pivoting bracket 20r and the second crossing member 20i intersects the pivoting centric line L8, the pivoting centric line L11 between the third hinge joint <NUM> and the second crossing member 20i intersects the pivoting centric line L10, the pivoting centric line L12 between the fourth hinge joint 20t and the right link <NUM> intersects the pivoting centric line L10, the pivoting centric line L14 between the first hinge joint 20p' and the left link 20j intersects the pivoting centric line L13, the pivoting centric line L15 between the second hinge joint 20q' and the left rear leg 20c intersects the pivoting centric line L13, the pivoting centric line L17 between the third hinge joint <NUM>' and the right link <NUM> intersects the pivoting centric line L16, and the pivoting centric line L18 between the fourth hinge joint 20t' and the right rear leg 20d intersects the pivoting centric line L16.

On the other hand, as shown in <FIG>, <FIG> and <FIG>, a stub 12b is formed on each of both sides of the backrest <NUM>, a groove <NUM> is formed on each of upper ends of the left rear leg 20c and the right rear leg 20d, and the stubs 12b are configured in the grooves <NUM>, respectively. Therefore, the seat <NUM> can be slidably and pivotally disposed on the supporting member <NUM> and the groove <NUM> though the seat frame <NUM> and the backrest <NUM>, respectively, so as to increase the stability while the stroller is in use and increase the convenience of folding after unlocking.

Claim 1:
A stroller (<NUM>) comprising,
a seat (<NUM>);
a stroller frame (<NUM>); and
a synchronous unlocking mechanism (<NUM>), configured on the seat (<NUM>) and the stroller frame (<NUM>), in which the seat (<NUM>) comprises a seat frame (<NUM>), a backrest (<NUM>) and a shaft (<NUM>), the seat frame (<NUM>) and the backrest (<NUM>) are pivotally connected through the shaft (<NUM>), and the stroller frame (<NUM>) comprises a fixing member (<NUM>) for selectively locking the stroller frame (<NUM>),
the synchronous unlocking mechanism (<NUM>) comprising:
a grip (<NUM>), pivotally connected to the seat frame (<NUM>) and/or the backrest (<NUM>);
a locking member (<NUM>), slidably disposed on the shaft (<NUM>), the seat frame (<NUM>) and
the backrest (<NUM>) along an axial direction of the shaft (<NUM>) and being coupled to the grip (<NUM>);
an elastic member (<NUM>), configured between the locking member (<NUM>) and the seat frame (<NUM>) or between the locking member (<NUM>) and the backrest (<NUM>); and
a towing member (<NUM>), connected to the grip (<NUM>) and the fixing member (<NUM>).