Patent Description:
Rotatable and foldable carriers, such as foldable strollers, are easy to store and carry, but are also prone to potential safety hazards. According to the test requirements of the European Regulation EN1888-<NUM>:<NUM> (<NUM>. <NUM> Test Standard for Folding System for Ease of storage or transportation), there shall be at least two separate and independent manual operating devices which fulfil the following conditions: where any one of the operating devices is released, it shall also automatically return to its original status and the locking device shall relock again. However, in the current stroller on the market, when, for example, a locking mechanism on a handle of the stroller is unintentionally pressed, the handle will pivot to a certain extent under the action of the child's weight or its own gravity, so that the locking mechanism cannot return to a locked position, causing certain safety hazards to the children in the stroller.

Accordingly, a foldable and movable carrier is provided, which can prevent pivoting of the carrier after unintentional release of a locking mechanism, so as to facilitate the relocking and refixing of the movable carrier.

According to the present invention, a foldable and movable carrier is provided, and includes:.

In the foldable and movable carrier, when the locking mechanism is unintentionally unlocked, since the first mating portion and the second mating portion are in a mating state, the first rod pivotally connected to the second rod will not pivot, so that the user can reset the locking mechanism, and thus the first rod can be restored to the locked state, and as a result, the safety of the entire foldable and movable carrier can be improved. In addition, when it is really necessary to release the locking, the locking mechanism can be pressed, and the first mating portion and the second mating portion can be released from the mating, for example, by applying a certain external force, so that the first rod can rotate and be folded relative to the second rod, to ensure the realization of the foldable function of the movable carrier.

In one of the embodiments, the first mating portion is a male connecting portion, and the second mating portion is a female connecting portion capable of detachably mating with the male connecting portion. Or, the first mating portion is a female connecting portion, and the second mating portion is a male connecting portion capable of detachably mating with the female connecting portion.

In one of the embodiments, one of the first mating portion and the second mating portion is an engaging groove; another one of the first mating portion and the second mating portion is an engaging protrusion capable of being engaged with the engaging groove.

In one of the embodiments, the engaging groove is a V-shaped groove. The V-shaped groove includes a first groove wall and a second groove wall that are arranged in a V shape. The engaging protrusion is an arc-shaped protrusion capable of being tangent to the first groove wall and the second groove wall.

In one of the embodiments, an included angle between the first groove wall and a plane where an opening of the V-shaped groove is located is in a range from <NUM>° to <NUM>°. An included angle between the second groove wall and the plane where the opening of the V-shaped groove is located is in a range from <NUM>° to <NUM>°. A height of the arc-shaped protrusion is in a range from <NUM> to <NUM>.

In one of the embodiments, the engaging protrusion is a serrated protrusion including at least two engaging teeth. The engaging groove is a serrated groove including at least two engaging grooves. The at least two engaging teeth are capable of mating with the at least two engaging grooves one by one.

In one of the embodiments, one of the first mating portion and the second mating portion is a plug hole; and another one of the first mating portion and the second mating portion is a plug pin capable of being plugged into the plug hole.

In one of the embodiments, a hole wall of the plug hole is capable of being elastically deformed; when the hole wall of the plug hole is elastically deformed, an inner diameter of the plug hole is greater than a diameter of the plug pin; when the hole wall of the plug hole is restored to its original shape, the inner diameter of the plug hole is less than the diameter of the plug pin. Or, the plug pin is capable of being elastically deformed; when the plug pin is elastically deformed, a diameter of the plug pin is less than an inner diameter of the plug hole; and when the plug pin is restored to its original state, the diameter of the plug pin is greater than the inner diameter of the plug hole.

In one of the embodiments, the foldable and movable carrier further includes a third rod. The first rod includes a first position, a second position, and a third position that are sequentially spaced apart in an extending direction of the first rod. The first mating portion is disposed in the third position. The third rod is pivotally connected to the first rod in the first position through the locking mechanism. When the locking mechanism is in the locked state, the first rod and the third rod are relatively fixed. When the locking mechanism is in the unlocked state, the first rod is capable of rotating relative to the third rod, so as to fold or unfold the movable carrier. The second rod is pivotally connected to the first rod in the second position.

In one of the embodiments, an end of the first rod is provided with a first rotating sector. An end of the second rod is provided with a second rotating sector. The first rotating sector is opposite to the second rotating sector. The second position is disposed at a circle center of the first rotating sector. A circle center of the second rotating sector is pivotally connected to the first rotating sector in the second position. The first mating portion is disposed at a circumferential edge of a surface of the first rotating sector facing the second rotating sector. The second mating portion is disposed at a circumferential edge of a surface of the second rotating sector facing the first rotating sector.

In one of the embodiments, a stopper is disposed on a side of the second rotating sector close to the third rod. When the first rod and the second rod are arranged at a second preset included angle, the first rotating sector abuts against the stopper.

In one of the embodiments, the locking mechanism includes:.

Illustration for reference signs:
<NUM>, first rod; <NUM>, first mating portion; <NUM>, first position; <NUM>, second position; <NUM>, third position; <NUM>, first rotating sector; <NUM>, arc-shaped guiding groove; <NUM>, engaging groove; <NUM>, first groove wall; <NUM>, second groove wall; <NUM>, third rod; <NUM>, second rod; <NUM>, second mating portion; <NUM>, second rotating sector; <NUM>, arc-shaped guiding rib; <NUM>, stopper; <NUM>, engaging protrusion; <NUM>, locking mechanism; <NUM>, first locking shell; <NUM>, first locking groove; <NUM>, elastic member; <NUM>, locking member; <NUM>, locking teeth; <NUM>, second locking shell; <NUM>, through hole; <NUM>, second locking groove; <NUM>, releasing member; <NUM>, pushing portion; <NUM>, handle; <NUM>, front support; <NUM>, rear support.

As shown in <FIG>, an embodiment of the present invention provides a foldable and movable carrier. The foldable and movable carrier includes a first rod <NUM>, a third rod <NUM>, and a second rod <NUM>. In this embodiment, the carrier may be a stroller. The stroller includes a handle <NUM>, a front support <NUM>, and a rear support <NUM>. In this embodiment, the first rod <NUM>, the third rod <NUM>, and the second rod <NUM> are all hollow rods, and are respectively sleeved on an end of the handle <NUM>, an end of the rear support <NUM>, and an end of the front support <NUM>. Certainly, in other embodiments, the first rod <NUM>, the third rod <NUM>, and the second rod <NUM> may also be connected to the handle <NUM>, the rear support <NUM>, and the front support <NUM> by other means, respectively. Or, the first rod <NUM>, the third rod <NUM>, and the second rod <NUM> are formed as a part of the handle <NUM>, a part of the rear support <NUM>, and a part of the front support <NUM>, respectively. In a word, the present application can be achieved as long as movements of the first rod <NUM>, the third rod <NUM>, and the second rod <NUM> can drive the handle <NUM>, the front support <NUM>, and the rear support <NUM> to move accordingly. The foldable and movable carrier <NUM> can prevent the handle <NUM> of the stroller from pivoting after a locking mechanism <NUM> is unintentionally released, so that the stroller can be relocked, and the safety performance of the stroller can be improved.

Specifically, as shown in <FIG> and <FIG>, the first rod <NUM> includes a first position <NUM>, a second position <NUM>, and a third position <NUM> which are sequentially spaced apart in an extending direction of the first rod <NUM>. It should be noted that the structure of the movable carrier of the present application is not limited to herein. In this embodiment, the first rod <NUM> is sleeved on a bottom end of the handle <NUM>. Certainly, the first rod <NUM> can also be connected to the bottom end of the handle <NUM> or be formed as a part of the bottom end of the handle <NUM>. A first mating portion <NUM> is disposed in the third position <NUM>.

The third rod <NUM> is pivotally connected to the first rod <NUM> in the first position <NUM> through the locking mechanism <NUM>. The locking mechanism <NUM> has a locked state and an unlocked state. When the locking mechanism <NUM> is in the locked state, the first rod <NUM> and the third rod <NUM> are relatively fixed and arranged at a first preset included angle. When the locking mechanism <NUM> is in the unlocked state, the first rod <NUM> can rotate relative to the third rod <NUM>. In this embodiment, the third rod <NUM> is sleeved on a top end of the rear support <NUM>. Certainly, the third rod <NUM> can also be connected to the top end of the rear support <NUM> or be formed as a part of the top end of the rear support <NUM> by other means. In this embodiment, the first preset included angle is an acute angle.

In this embodiment, as shown in <FIG>, the locking mechanism <NUM> includes a first locking shell <NUM>, an elastic member <NUM>, a locking member <NUM>, a second locking shell <NUM>, and a releasing member <NUM>, which are arranged in sequence. The first locking shell <NUM> is fixed on the first rod <NUM> or is a part of the first rod <NUM>. The first locking shell <NUM> includes a first locking groove <NUM>. The second locking shell <NUM> is fixed on the third rod <NUM>, or is formed as a part of the third rod <NUM>. The second locking shell <NUM> includes a second locking groove <NUM>. The locking member <NUM> includes at least two locking teeth <NUM> arranged at a predetermined angle. Shapes of the first locking groove <NUM> and the second locking groove <NUM> are both adapted to a shape of the locking member <NUM>. In this embodiment, the locking member <NUM> is a gear-shaped locking member <NUM>. The first locking groove <NUM> and the second locking groove <NUM> are both gear-shaped locking grooves mating with the gear-shaped locking member <NUM>. The locking member <NUM> has a locked state and an unlocked state. When the locking member <NUM> is in the locked state, the locking member <NUM> is arranged in both the first locking shell <NUM> and the second locking shell <NUM> to limit the rotation of the second locking shell <NUM> relative to the first locking shell <NUM>. When the locking member <NUM> is in the unlocked state, the locking member <NUM> is withdrawn from the first locking groove <NUM> or the second locking groove <NUM> to allow the second locking shell <NUM> to rotate relative to the first locking shell <NUM>. The elastic member <NUM> is operably connected to the locking member <NUM>, for maintaining the locking member <NUM> in the locked state. In this embodiment, the elastic member <NUM> is a spring. Two ends of the spring abut against the first locking shell <NUM> and the locking member <NUM>, respectively. The releasing member <NUM> is operably connected to the locking member <NUM>, for driving the locking member <NUM> to move against the elastic force of the elastic member <NUM> to switch the locking member <NUM> from the locked state to the unlocked state. In this embodiment, the releasing member <NUM> is a release button. The release button is provided with a pushing portion <NUM>. The second locking shell <NUM> is provided with a through hole <NUM> through which the pushing portion <NUM> can pass.

In this way, when the releasing member <NUM> is not pressed, and when the locking member <NUM> is in the locked state, the locking member <NUM> is locked into both the first locking shell <NUM> and the second locking shell <NUM> under the elastic force of the elastic member <NUM> that is a return spring. In this case, the first locking shell <NUM> and the second locking shell <NUM> are in the locked state, that is, the first rod <NUM> and the third rod <NUM> are in the locked state. When the releasing member <NUM> is pressed, the pushing portion <NUM> can pass through the through hole <NUM> to press the second locking shell <NUM> and the locking member <NUM>, so that the locking member <NUM> is separated from the first locking groove <NUM> or the second locking groove <NUM>. In this case, the first locking shell <NUM> and the second locking shell <NUM> are in the released state, that is, the first rod <NUM> can rotate relative to the third rod <NUM>. The locking mechanism <NUM> has a simple structure and can enable the first rod <NUM> and the third rod <NUM> to switch between the locked state and the unlocked state. However, when the releasing member <NUM> is unintentionally pressed, the first rod <NUM> will pivot under the action of external force or its own gravity, so that the locking teeth <NUM> of the locking member <NUM> are misaligned with the first locking groove <NUM> or the second locking groove <NUM>, so that it is difficult for the locking member <NUM> to reengage into the first locking groove <NUM> or the second locking groove <NUM> such that the first locking shell <NUM> and the second locking shell <NUM> are in the locked state again. That is, it is difficult to bring the first rod <NUM> and the third rod <NUM> into a relatively locked and fixed state again.

The second rod <NUM> is pivotally connected to the first rod <NUM> in the second position <NUM>. The second rod <NUM> is provided with a second mating portion <NUM> detachably mating with the first mating portion <NUM>. When the first mating portion <NUM> mates with the second mating portion <NUM>, the first rod <NUM> and the second rod <NUM> are relatively fixed and arranged at a second preset included angle. When the first mating portion <NUM> and the second mating portion <NUM> are released from mating, the first rod <NUM> can rotate relative to the second rod <NUM>, and an included angle facing the third rod <NUM>, between the first rod <NUM> and the second rod <NUM> is less than or equal to the second preset included angle. In this embodiment, the second preset included angle is <NUM> degrees. In this way, when the first mating portion <NUM> mates with the second mating portion <NUM>, the first rod <NUM> and the second rod <NUM> are on the same straight line. In addition, since the first preset included angle is an acute angle, when the locking mechanism <NUM> is in the locked and fixed state, a combined structure of the first rod <NUM> and the second rod <NUM>, and the third rod <NUM> form a triangular support structure. Furthermore, because the included angle facing the third rod <NUM>, between the first rod <NUM> and the second rod <NUM> is always kept less than or equal to the second preset included angle, that is, when the locking mechanism <NUM> is in the locked state, the first rod <NUM> can neither rotate from the third rod <NUM> to the second rod <NUM> nor from the second rod <NUM> to the third rod <NUM>. Therefore, when the locking mechanism <NUM> is in the locked state, the first rod <NUM> and the second rod <NUM> can be kept at the first preset included angle, thereby providing a stable triangular support structure for the whole stroller.

In this way, when the locking mechanism <NUM> is in the locked state, the first rod <NUM>, the second rod <NUM>, and the third rod <NUM> form a stable triangular support structure, so that the first rod <NUM> and the second rod <NUM> are relatively fixed, and the first rod <NUM> and the third rod <NUM> are also relatively fixed. When the locking mechanism <NUM> is unintentionally pressed and unlocked, since the first mating portion <NUM> which mates with the second mating portion <NUM> of the second rod <NUM> is disposed in the third position <NUM> of the first rod <NUM>, the first mating portion <NUM> mates with the second mating portion <NUM>, the first rod <NUM> and the second rod <NUM> are still relatively fixed, and the first rod <NUM> will not pivot. In this way, the first rod <NUM> can be prevented from pivoting in a state of unintentional release such that the locking mechanism <NUM> cannot be restored to the locked state, and the first rod <NUM> and the second rod <NUM> cannot be locked and fixed. When the foldable and movable carrier <NUM> needs to be folded, the locking mechanism <NUM> is unlocked, and a certain external force is applied to the first rod <NUM> at the same time, so that the first mating portion <NUM> and the second mating portion <NUM> are released from mating. In this way, the relative fixed state among the first rod <NUM>, the third rod <NUM>, and the second rod <NUM> can be released, and the foldable and movable carrier <NUM> can be folded.

In an embodiment, as shown in <FIG>, a bottom end of the first rod <NUM> is provided with a first rotating sector <NUM>, a top end of the second rod <NUM> is provided with a second rotating sector <NUM>. The second position <NUM> is disposed at a circle center of the first rotating sector <NUM>. A circle center of the second rotating sector <NUM> is pivotally connected to the first rotating sector <NUM> in the second position <NUM> (i.e., the circle center of the first rotating sector <NUM>). A surface of the first rotating sector <NUM> facing the second rotating sector <NUM> is provided with at least two arc-shaped guiding grooves <NUM> that are concentric with the first rotating sector <NUM>. A surface of the second rotating sector <NUM> facing the first rotating sector <NUM> is provided with at least two arc-shaped guiding ribs <NUM> that are concentric with the second rotating sector <NUM>. The arc-shaped guiding ribs <NUM> mates with the arc-shaped guiding grooves <NUM> in one-to-one correspondence, to guide the rotations of the first rod <NUM> and the second rod <NUM>, to facilitate the folding of the movable carrier. It can be understood that the locations of the arc-shaped guiding grooves <NUM> and the locations of the arc-shaped guiding ribs <NUM> can be interchanged.

In an embodiment, as shown in <FIG> and <FIG>, the first mating portion <NUM> is disposed at a circumferential edge of the surface of the first rotating sector <NUM> facing the second rotating sector <NUM>, and the second mating portion <NUM> is disposed at a circumferential edge of the surface of the second rotating sector <NUM> facing the first rotating sector <NUM>. In this way, a distance from the second position <NUM> to the third position <NUM> is relatively large. According to the lever principle, when the movable carrier is folded, the external force required to be applied to release the mating between the first mating portion <NUM> and the second mating portion <NUM> is smaller, which means that less effort is required when the movable carrier is folded. Certainly, the locations of the first mating portion <NUM> and the second mating portion <NUM> can also be arranged according to actual needs. For example, the first mating portion <NUM> and the second mating portion <NUM> can be arranged closer to the circle center of the first rotating sector <NUM> and the circle center of the second rotating sector <NUM>, respectively, so that when the locking mechanism <NUM> is unintentionally released, the first rod <NUM> is more difficult to pivot, etc., which is not limited to herein.

Further, a stopper <NUM> is disposed on a side of the second rotating sector <NUM> close to the third rod <NUM>. When the first rod <NUM> and the second rod <NUM> are arranged at the second preset included angle, the first rotating sector <NUM> abuts against the stopper <NUM>. The stopper <NUM> may be a stopping protrusion, a stopping slope, or the like. In this embodiment, the stopper <NUM> is a stopping slope disposed at the circumferential edge of the surface of the second rotating sector <NUM> facing the first rotating sector <NUM>, and the stopping slope is gradually raised in a direction of approaching the third rod <NUM>. In this way, it can be ensured that the included angle facing the third rod <NUM>, between the first rod <NUM> and the second rod <NUM> is always less than or equal to the second preset included angle.

Optionally, the first mating portion <NUM> is a male connecting portion, and the second mating portion <NUM> is a female connecting portion that can detachably mate with the male connecting portion. Or, the first mating portion <NUM> is a female connecting portion, and the second mating portion <NUM> is a male connecting portion that can detachably mate with the female connecting portion.

In an embodiment, as shown in <FIG> and <FIG>, the first mating portion <NUM> is an engaging groove <NUM>, and the second mating portion <NUM> is an engaging protrusion <NUM> capable of being engaged with the engaging groove <NUM>. In this way, when the locking mechanism <NUM> is unintentionally unlocked, since the engaging protrusion <NUM> of the second rod <NUM> is engaged into the engaging groove <NUM> of the first rod <NUM>, the first rod <NUM> is not easy to pivot under the action of external force or its own gravity, so that the locking mechanism <NUM> can be restored to the locked state again, and thus the movable carrier can be relocked and refixed. When the movable carrier needs to be folded, it is only necessary to apply a certain external force on the first rod <NUM> to make the engaging protrusion <NUM> rotate out from the engaging groove <NUM>, which ensures the foldable function of the movable carrier. It can be understood that the first mating portion <NUM> can also be the engaging protrusion <NUM>, and the second mating portion <NUM> can be the engaging groove <NUM> capable of being engaged with the engaging protrusion <NUM>.

In this embodiment, the engaging groove <NUM> is disposed on the circumferential edge of the surface of the first rotating sector <NUM> facing the second rotating sector <NUM>, and the engaging protrusion <NUM> is disposed on the circumferential edge of the surface of the second rotating sector <NUM> facing the first rotating sector <NUM>. Certainly, in other embodiments, the engaging groove <NUM> may also be disposed in other positions of the first rotating sector <NUM>, and the engaging protrusion <NUM> may also be disposed in other positions of the second rotating sector <NUM>.

Further, as shown in <FIG>, the engaging groove <NUM> is a V-shaped groove. The V-shaped groove includes a first groove wall <NUM> and a second groove wall <NUM> that are arranged in a V shape. The engaging protrusion <NUM> is an arc-shaped protrusion capable of being tangent to the groove walls of the V-shaped groove. That is, a cross-sectional shape of the engaging groove <NUM> perpendicular to the first rod <NUM> is V-shaped, and a cross-sectional shape of the engaging protrusion <NUM> perpendicular to the third rod <NUM> is arc-shaped. In this way, when the first rod <NUM> rotates to be engaged and fixed to the third rod <NUM>, the engaging protrusion <NUM> can be more smoothly engaged into the engaging groove <NUM>. When the fixing between the first rod <NUM> and the third rod <NUM> is released, the engaging protrusion <NUM> can also be easily rotated out from the engaging groove <NUM>. Optionally, a first included angle between the first groove wall <NUM> and a plane where an opening of the V-shaped groove is located is in a range from <NUM>° to <NUM>°. In this embodiment, the first included angle is <NUM>°. A second included angle between the second groove wall <NUM> and the plane where the opening of the V-shaped groove is located is in a range from <NUM>° to <NUM>°. In this embodiment, the second included angle is <NUM>°. A height of the arc-shaped protrusion is in a range from <NUM> to <NUM>. In this embodiment, the height is <NUM>. The above configuration can prevent the realization of the foldable function of the movable carrier from being affected even when the locking mechanism <NUM> is unintentionally released while the first rod <NUM> is pivoting.

Further, the engaging protrusion <NUM> is a serrated protrusion including at least two engaging teeth, and the engaging groove <NUM> is a serrated groove including at least two engaging grooves. The at least two engaging teeth can mate with the at least two engaging grooves one by one. Compared with the mating between the single protrusion and the groove, the mating structure of the serrated protrusion and the serrated groove can provide a larger friction force, so that the first rod <NUM> has a stronger anti-pivoting ability during the unintentional release. Certainly, under the condition of the same required anti-pivoting ability, the height of the serrated protrusion can be less than that of the single protrusion, and the depth of the corresponding engaging groove <NUM> can also be less than that of the single groove.

In another embodiment, the first mating portion <NUM> may be a plug hole, and the second mating portion <NUM> may be a plug pin capable of being plugged into the plug hole. In this way, when the locking mechanism <NUM> is unintentionally unlocked, since the plug pin of the first rod <NUM> is plugged into the plug hole of the second rod <NUM>, the first rod <NUM> is not easy to pivot under the action of external force or its own gravity, so that it is convenient to restore the locking mechanism <NUM> to the locked state again, and thus the foldable and movable carrier <NUM> can be relocked and refixed. When the movable carrier needs to be folded, it is only necessary to apply a certain external force to the first rod <NUM> to make the plug pin rotate out from the plug hole, which ensures the foldable function of the foldable and movable carrier. It can be understood that the first mating portion <NUM> can also be a plug pin, and the second mating portion <NUM> can also be a plug hole capable of being plugged with the plug pin.

Further, a hole wall of the plug hole can be elastically deformed. When the hole wall of the plug hole is elastically deformed, an inner diameter of the plug hole is greater than a diameter of the plug pin. When the hole wall of the plug hole is restored to its original shape, the inner diameter of the plug hole is less than the diameter of the plug pin. Or, the plug pin can be elastically deformed. When the plug pin is elastically deformed, the diameter of the plug pin is less than the inner diameter of the plug hole; and when the plug pin is restored to its original state, the diameter of the plug pin is greater than the inner diameter of the plug hole. On the one hand, this configuration facilitates the plug pin plugging into the plug hole, and keeping the plug pin stably in the plug hole without easily coming out of the plug hole; and on the other hand, this configuration is also convenient for the plug pin to come out from the plug hole when external force is applied.

Optionally, both the first rod <NUM> and the second rod <NUM> are made of deformable plastic materials, so as to facilitate the mating and separation of the first mating portion <NUM> and the second mating portion <NUM>.

The above-mentioned foldable and movable carrier <NUM> at least have the following technical effects.

When the locking mechanism <NUM> is unintentionally unlocked, since the first mating portion <NUM> and the second mating portion <NUM> are in a mating state, the first rod <NUM> pivotally connected to the second rod <NUM> is not easy to pivot, so that the user can reset the locking mechanism <NUM>, and thus the movable carrier can be restored to the locked and fixed state, and as a result, the safety of the entire movable carrier can be improved. In addition, when it is really necessary to release the locking, the locking mechanism <NUM> can be pressed, and the first mating portion <NUM> and the second mating portion <NUM> can be released from the mating, for example, by applying a certain external force, so that the first rod <NUM> can rotate and be folded relative to the second rod <NUM>, to ensure the realization of the foldable function of the movable carrier.

Claim 1:
A foldable and movable carrier (<NUM>), comprising:
a locking mechanism (<NUM>) having a locked state and an unlocked state;
a first rod (<NUM>) provided with a first mating portion (<NUM>); and
a second rod (<NUM>) pivotally connected to the first rod (<NUM>), and the second rod (<NUM>) being provided with a second mating portion (<NUM>) detachably mating with the first mating portion (<NUM>);
characterized in that, when the locking mechanism (<NUM>) is in the locked state, the first rod (<NUM>) and the second rod (<NUM>) are relatively fixed; when the locking mechanism (<NUM>) is in the unlocked state, if the first mating portion (<NUM>) mates with the second mating portion (<NUM>), the first rod (<NUM>) and the second rod (<NUM>) are relatively fixed, if the first mating portion (<NUM>) and the second mating portion (<NUM>) are released from mating, the first rod (<NUM>) is capable of rotating relative to the second rod (<NUM>), so as to fold or unfold the movable carrier (<NUM>).